Merge tag 'spi-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "Not the biggest set of changes for SPI but a bit of a pickup in
  activity on the core:

   - Support for memory mapped read from flash devices via a SPI
     controller.

   - The beginnings of a message rewriting framework in the core which
     should in time allow us to support transforming messages to work
     around the limits of controllers or optimise the performance for
     controllers transparently to calling drivers.

   - Updates to the PXA2xx, the main functional change being to improve
     the ACPI support.

   - A new driver for the Analog Devices AXI SPI engine"

* tag 'spi-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (66 commits)
  spi: Add gfp parameter to kernel-doc to fix build warning
  spi: Fix htmldocs build error due struct spi_replaced_transfers
  spi: rockchip: covert rsd_nsecs to u32 type
  spi: rockchip: header file cleanup
  spi: xilinx: Add devicetree binding for spi-xilinx
  spi: respect the maximum segment size of DMA device
  spi: rockchip: check requesting dma channel with EPROBE_DEFER
  spi: rockchip: migrate to dmaengine_terminate_async
  spi: rockchip: check return value of dmaengine_prep_slave_sg
  spi: core: Fix deadlock when sending messages
  spi/rockchip: fix endian mode for 16-bit transfers
  spi/rockchip: Make sure spi clk is on in rockchip_spi_set_cs
  spi: pxa2xx: Use newer more explicit DMAengine terminate API
  spi: pxa2xx: Add support for Intel Broxton B-Step
  spi: lp-8841: return correct error code from probe
  spi: imx: drop bogus tests for rx/tx bufs in DMA transfer
  spi: imx: set MX51_ECSPI_CTRL_SMC bit in setup function
  spi: imx: make some register defines simpler
  spi: imx: remove unnecessary bit clearing in mx51_ecspi_config
  spi: imx: add support for all SPI word width for DMA
  ...

Documentation/devicetree/bindings/spi/adi,axi-spi-engine.txt

+Analog Devices AXI SPI Engine controller Device Tree Bindings
+
+Required properties:
+- compatible		: Must be "adi,axi-spi-engine-1.00.a""
+- reg			: Physical base address and size of the register map.
+- interrupts		: Property with a value describing the interrupt
+			  number.
+- clock-names		: List of input clock names - "s_axi_aclk", "spi_clk"
+- clocks		: Clock phandles and specifiers (See clock bindings for
+			  details on clock-names and clocks).
+- #address-cells	: Must be <1>
+- #size-cells		: Must be <0>
+
+Optional subnodes:
+	Subnodes are use to represent the SPI slave devices connected to the SPI
+	master. They follow the generic SPI bindings as outlined in spi-bus.txt.
+
+Example:
+
+    spi@@44a00000 {
+		compatible = "adi,axi-spi-engine-1.00.a";
+		reg = <0x44a00000 0x1000>;
+		interrupts = <0 56 4>;
+		clocks = <&clkc 15 &clkc 15>;
+		clock-names = "s_axi_aclk", "spi_clk";
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		/* SPI devices */
+    };

Documentation/devicetree/bindings/spi/icpdas-lp8841-spi-rtc.txt

+* ICP DAS LP-8841 SPI Controller for RTC
+
+ICP DAS LP-8841 contains a DS-1302 RTC. RTC is connected to an IO
+memory register, which acts as an SPI master device.
+
+The device uses the standard MicroWire half-duplex transfer timing.
+Master output is set on low clock and sensed by the RTC on the rising
+edge. Master input is set by the RTC on the trailing edge and is sensed
+by the master on low clock.
+
+Required properties:
+
+- #address-cells: should be 1
+
+- #size-cells: should be 0
+
+- compatible: should be "icpdas,lp8841-spi-rtc"
+
+- reg: should provide IO memory address
+
+Requirements to SPI slave nodes:
+
+- There can be only one slave device.
+
+- The spi slave node should claim the following flags which are
+  required by the spi controller.
+
+  - spi-3wire: The master itself has only 3 wire. It cannor work in
+    full duplex mode.
+
+  - spi-cs-high: DS-1302 has active high chip select line. The master
+    doesn't support active low.
+
+  - spi-lsb-first: DS-1302 requires least significant bit first
+    transfers. The master only support this type of bit ordering.
+
+
+Example:
+
+spi@901c {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	compatible = "icpdas,lp8841-spi-rtc";
+	reg = <0x901c 0x1>;
+
+	rtc@0 {
+		compatible = "maxim,ds1302";
+		reg = <0>;
+		spi-max-frequency = <500000>;
+		spi-3wire;
+		spi-lsb-first;
+		spi-cs-high;
+	};
+};

Documentation/devicetree/bindings/spi/spi-rockchip.txt

@@ -9,6 +9,7 @@ Required Properties:
     "rockchip,rk3066-spi" for rk3066.
     "rockchip,rk3188-spi", "rockchip,rk3066-spi" for rk3188.
     "rockchip,rk3288-spi", "rockchip,rk3066-spi" for rk3288.
+    "rockchip,rk3399-spi", "rockchip,rk3066-spi" for rk3399.
 - reg: physical base address of the controller and length of memory mapped
        region.
 - interrupts: The interrupt number to the cpu. The interrupt specifier format

Documentation/devicetree/bindings/spi/spi-xilinx.txt

+Xilinx SPI controller Device Tree Bindings
+-------------------------------------------------
+
+Required properties:
+- compatible		: Should be "xlnx,xps-spi-2.00.a" or "xlnx,xps-spi-2.00.b"
+- reg			: Physical base address and size of SPI registers map.
+- interrupts		: Property with a value describing the interrupt
+			  number.
+- interrupt-parent	: Must be core interrupt controller
+
+Optional properties:
+- xlnx,num-ss-bits	: Number of chip selects used.
+
+Example:
+	axi_quad_spi@41e00000 {
+			compatible = "xlnx,xps-spi-2.00.a";
+			interrupt-parent = <&intc>;
+			interrupts = <0 31 1>;
+			reg = <0x41e00000 0x10000>;
+			xlnx,num-ss-bits = <0x1>;
+	};
+

drivers/spi/Kconfig

@@ -75,11 +75,26 @@ config SPI_ATMEL
 	  This selects a driver for the Atmel SPI Controller, present on
 	  many AT32 (AVR32) and AT91 (ARM) chips.
 
+config SPI_AU1550
+	tristate "Au1550/Au1200/Au1300 SPI Controller"
+	depends on MIPS_ALCHEMY
+	select SPI_BITBANG
+	help
+	  If you say yes to this option, support will be included for the
+	  PSC SPI controller found on Au1550, Au1200 and Au1300 series.
+
+config SPI_AXI_SPI_ENGINE
+	tristate "Analog Devices AXI SPI Engine controller"
+	depends on HAS_IOMEM
+	help
+	  This enables support for the Analog Devices AXI SPI Engine SPI controller.
+	  It is part of the SPI Engine framework that is used in some Analog Devices
+	  reference designs for FPGAs.
+
 config SPI_BCM2835
 	tristate "BCM2835 SPI controller"
 	depends on GPIOLIB
 	depends on ARCH_BCM2835 || COMPILE_TEST
-	depends on GPIOLIB
 	help
 	  This selects a driver for the Broadcom BCM2835 SPI master.
 
@@ -90,8 +105,7 @@ config SPI_BCM2835
 
 config SPI_BCM2835AUX
 	tristate "BCM2835 SPI auxiliary controller"
-	depends on ARCH_BCM2835 || COMPILE_TEST
-	depends on GPIOLIB
+	depends on (ARCH_BCM2835 && GPIOLIB) || COMPILE_TEST
 	help
 	  This selects a driver for the Broadcom BCM2835 SPI aux master.
 
@@ -118,14 +132,6 @@ config SPI_BFIN_SPORT
 	help
 	  Enable support for a SPI bus via the Blackfin SPORT peripheral.
 
-config SPI_AU1550
-	tristate "Au1550/Au1200/Au1300 SPI Controller"
-	depends on MIPS_ALCHEMY
-	select SPI_BITBANG
-	help
-	  If you say yes to this option, support will be included for the
-	  PSC SPI controller found on Au1550, Au1200 and Au1300 series.
-
 config SPI_BCM53XX
 	tristate "Broadcom BCM53xx SPI controller"
 	depends on ARCH_BCM_5301X
@@ -197,6 +203,23 @@ config SPI_DAVINCI
 	help
 	  SPI master controller for DaVinci/DA8x/OMAP-L/AM1x SPI modules.
 
+config SPI_DESIGNWARE
+	tristate "DesignWare SPI controller core support"
+	help
+	  general driver for SPI controller core from DesignWare
+
+config SPI_DW_PCI
+	tristate "PCI interface driver for DW SPI core"
+	depends on SPI_DESIGNWARE && PCI
+
+config SPI_DW_MID_DMA
+	bool "DMA support for DW SPI controller on Intel MID platform"
+	depends on SPI_DW_PCI && DW_DMAC_PCI
+
+config SPI_DW_MMIO
+	tristate "Memory-mapped io interface driver for DW SPI core"
+	depends on SPI_DESIGNWARE
+
 config SPI_DLN2
        tristate "Diolan DLN-2 USB SPI adapter"
        depends on MFD_DLN2
@@ -271,6 +294,16 @@ config SPI_LM70_LLP
 	  which interfaces to an LM70 temperature sensor using
 	  a parallel port.
 
+config SPI_LP8841_RTC
+	tristate "ICP DAS LP-8841 SPI Controller for RTC"
+	depends on MACH_PXA27X_DT || COMPILE_TEST
+	help
+	  This driver provides an SPI master device to drive Maxim
+	  DS-1302 real time clock.
+
+	  Say N here unless you plan to run the kernel on an ICP DAS
+	  LP-8x4x industrial computer.
+
 config SPI_MPC52xx
 	tristate "Freescale MPC52xx SPI (non-PSC) controller support"
 	depends on PPC_MPC52xx
@@ -346,6 +379,13 @@ config SPI_MT65XX
 	  say Y or M here.If you are not sure, say N.
 	  SPI drivers for Mediatek MT65XX and MT81XX series ARM SoCs.
 
+config SPI_NUC900
+	tristate "Nuvoton NUC900 series SPI"
+	depends on ARCH_W90X900
+	select SPI_BITBANG
+	help
+	  SPI driver for Nuvoton NUC900 series ARM SoCs
+
 config SPI_OC_TINY
 	tristate "OpenCores tiny SPI"
 	depends on GPIOLIB || COMPILE_TEST
@@ -415,10 +455,6 @@ config SPI_PPC4xx
 	help
 	  This selects a driver for the PPC4xx SPI Controller.
 
-config SPI_PXA2XX_DMA
-	def_bool y
-	depends on SPI_PXA2XX
-
 config SPI_PXA2XX
 	tristate "PXA2xx SSP SPI master"
 	depends on (ARCH_PXA || PCI || ACPI)
@@ -451,7 +487,7 @@ config SPI_RB4XX
 
 config SPI_RSPI
 	tristate "Renesas RSPI/QSPI controller"
-	depends on SUPERH || ARCH_SHMOBILE || COMPILE_TEST
+	depends on SUPERH || ARCH_RENESAS || COMPILE_TEST
 	help
 	  SPI driver for Renesas RSPI and QSPI blocks.
 
@@ -501,7 +537,7 @@ config SPI_SC18IS602
 config SPI_SH_MSIOF
 	tristate "SuperH MSIOF SPI controller"
 	depends on HAVE_CLK && HAS_DMA
-	depends on SUPERH || ARCH_SHMOBILE || COMPILE_TEST
+	depends on SUPERH || ARCH_RENESAS || COMPILE_TEST
 	help
 	  SPI driver for SuperH and SH Mobile MSIOF blocks.
 
@@ -520,7 +556,7 @@ config SPI_SH_SCI
 
 config SPI_SH_HSPI
 	tristate "SuperH HSPI controller"
-	depends on ARCH_SHMOBILE || COMPILE_TEST
+	depends on ARCH_RENESAS || COMPILE_TEST
 	help
 	  SPI driver for SuperH HSPI blocks.
 
@@ -647,34 +683,10 @@ config SPI_ZYNQMP_GQSPI
 	help
 	  Enables Xilinx GQSPI controller driver for Zynq UltraScale+ MPSoC.
 
-config SPI_NUC900
-	tristate "Nuvoton NUC900 series SPI"
-	depends on ARCH_W90X900
-	select SPI_BITBANG
-	help
-	  SPI driver for Nuvoton NUC900 series ARM SoCs
-
 #
 # Add new SPI master controllers in alphabetical order above this line
 #
 
-config SPI_DESIGNWARE
-	tristate "DesignWare SPI controller core support"
-	help
-	  general driver for SPI controller core from DesignWare
-
-config SPI_DW_PCI
-	tristate "PCI interface driver for DW SPI core"
-	depends on SPI_DESIGNWARE && PCI
-
-config SPI_DW_MID_DMA
-	bool "DMA support for DW SPI controller on Intel MID platform"
-	depends on SPI_DW_PCI && DW_DMAC_PCI
-
-config SPI_DW_MMIO
-	tristate "Memory-mapped io interface driver for DW SPI core"
-	depends on SPI_DESIGNWARE
-
 #
 # There are lots of SPI device types, with sensors and memory
 # being probably the most widely used ones.

drivers/spi/Makefile

@@ -15,6 +15,7 @@ obj-$(CONFIG_SPI_ALTERA)		+= spi-altera.o
 obj-$(CONFIG_SPI_ATMEL)			+= spi-atmel.o
 obj-$(CONFIG_SPI_ATH79)			+= spi-ath79.o
 obj-$(CONFIG_SPI_AU1550)		+= spi-au1550.o
+obj-$(CONFIG_SPI_AXI_SPI_ENGINE)	+= spi-axi-spi-engine.o
 obj-$(CONFIG_SPI_BCM2835)		+= spi-bcm2835.o
 obj-$(CONFIG_SPI_BCM2835AUX)		+= spi-bcm2835aux.o
 obj-$(CONFIG_SPI_BCM53XX)		+= spi-bcm53xx.o
@@ -46,6 +47,7 @@ obj-$(CONFIG_SPI_GPIO)			+= spi-gpio.o
 obj-$(CONFIG_SPI_IMG_SPFI)		+= spi-img-spfi.o
 obj-$(CONFIG_SPI_IMX)			+= spi-imx.o
 obj-$(CONFIG_SPI_LM70_LLP)		+= spi-lm70llp.o
+obj-$(CONFIG_SPI_LP8841_RTC)		+= spi-lp8841-rtc.o
 obj-$(CONFIG_SPI_MESON_SPIFC)		+= spi-meson-spifc.o
 obj-$(CONFIG_SPI_MPC512x_PSC)		+= spi-mpc512x-psc.o
 obj-$(CONFIG_SPI_MPC52xx_PSC)		+= spi-mpc52xx-psc.o
@@ -62,8 +64,7 @@ obj-$(CONFIG_SPI_TI_QSPI)		+= spi-ti-qspi.o
 obj-$(CONFIG_SPI_ORION)			+= spi-orion.o
 obj-$(CONFIG_SPI_PL022)			+= spi-pl022.o
 obj-$(CONFIG_SPI_PPC4xx)		+= spi-ppc4xx.o
-spi-pxa2xx-platform-objs		:= spi-pxa2xx.o
-spi-pxa2xx-platform-$(CONFIG_SPI_PXA2XX_DMA)	+= spi-pxa2xx-dma.o
+spi-pxa2xx-platform-objs		:= spi-pxa2xx.o spi-pxa2xx-dma.o
 obj-$(CONFIG_SPI_PXA2XX)		+= spi-pxa2xx-platform.o
 obj-$(CONFIG_SPI_PXA2XX_PCI)		+= spi-pxa2xx-pci.o
 obj-$(CONFIG_SPI_QUP)			+= spi-qup.o

drivers/spi/spi-axi-spi-engine.c

+/*
+ * SPI-Engine SPI controller driver
+ * Copyright 2015 Analog Devices Inc.
+ *  Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+
+#define SPI_ENGINE_VERSION_MAJOR(x)	((x >> 16) & 0xff)
+#define SPI_ENGINE_VERSION_MINOR(x)	((x >> 8) & 0xff)
+#define SPI_ENGINE_VERSION_PATCH(x)	(x & 0xff)
+
+#define SPI_ENGINE_REG_VERSION			0x00
+
+#define SPI_ENGINE_REG_RESET			0x40
+
+#define SPI_ENGINE_REG_INT_ENABLE		0x80
+#define SPI_ENGINE_REG_INT_PENDING		0x84
+#define SPI_ENGINE_REG_INT_SOURCE		0x88
+
+#define SPI_ENGINE_REG_SYNC_ID			0xc0
+
+#define SPI_ENGINE_REG_CMD_FIFO_ROOM		0xd0
+#define SPI_ENGINE_REG_SDO_FIFO_ROOM		0xd4
+#define SPI_ENGINE_REG_SDI_FIFO_LEVEL		0xd8
+
+#define SPI_ENGINE_REG_CMD_FIFO			0xe0
+#define SPI_ENGINE_REG_SDO_DATA_FIFO		0xe4
+#define SPI_ENGINE_REG_SDI_DATA_FIFO		0xe8
+#define SPI_ENGINE_REG_SDI_DATA_FIFO_PEEK	0xec
+
+#define SPI_ENGINE_INT_CMD_ALMOST_EMPTY		BIT(0)
+#define SPI_ENGINE_INT_SDO_ALMOST_EMPTY		BIT(1)
+#define SPI_ENGINE_INT_SDI_ALMOST_FULL		BIT(2)
+#define SPI_ENGINE_INT_SYNC			BIT(3)
+
+#define SPI_ENGINE_CONFIG_CPHA			BIT(0)
+#define SPI_ENGINE_CONFIG_CPOL			BIT(1)
+#define SPI_ENGINE_CONFIG_3WIRE			BIT(2)
+
+#define SPI_ENGINE_INST_TRANSFER		0x0
+#define SPI_ENGINE_INST_ASSERT			0x1
+#define SPI_ENGINE_INST_WRITE			0x2
+#define SPI_ENGINE_INST_MISC			0x3
+
+#define SPI_ENGINE_CMD_REG_CLK_DIV		0x0
+#define SPI_ENGINE_CMD_REG_CONFIG		0x1
+
+#define SPI_ENGINE_MISC_SYNC			0x0
+#define SPI_ENGINE_MISC_SLEEP			0x1
+
+#define SPI_ENGINE_TRANSFER_WRITE		0x1
+#define SPI_ENGINE_TRANSFER_READ		0x2
+
+#define SPI_ENGINE_CMD(inst, arg1, arg2) \
+	(((inst) << 12) | ((arg1) << 8) | (arg2))
+
+#define SPI_ENGINE_CMD_TRANSFER(flags, n) \
+	SPI_ENGINE_CMD(SPI_ENGINE_INST_TRANSFER, (flags), (n))
+#define SPI_ENGINE_CMD_ASSERT(delay, cs) \
+	SPI_ENGINE_CMD(SPI_ENGINE_INST_ASSERT, (delay), (cs))
+#define SPI_ENGINE_CMD_WRITE(reg, val) \
+	SPI_ENGINE_CMD(SPI_ENGINE_INST_WRITE, (reg), (val))
+#define SPI_ENGINE_CMD_SLEEP(delay) \
+	SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SLEEP, (delay))
+#define SPI_ENGINE_CMD_SYNC(id) \
+	SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SYNC, (id))
+
+struct spi_engine_program {
+	unsigned int length;
+	uint16_t instructions[];
+};
+
+struct spi_engine {
+	struct clk *clk;
+	struct clk *ref_clk;
+
+	spinlock_t lock;
+
+	void __iomem *base;
+
+	struct spi_message *msg;
+	struct spi_engine_program *p;
+	unsigned cmd_length;
+	const uint16_t *cmd_buf;
+
+	struct spi_transfer *tx_xfer;
+	unsigned int tx_length;
+	const uint8_t *tx_buf;
+
+	struct spi_transfer *rx_xfer;
+	unsigned int rx_length;
+	uint8_t *rx_buf;
+
+	unsigned int sync_id;
+	unsigned int completed_id;
+
+	unsigned int int_enable;
+};
+
+static void spi_engine_program_add_cmd(struct spi_engine_program *p,
+	bool dry, uint16_t cmd)
+{
+	if (!dry)
+		p->instructions[p->length] = cmd;
+	p->length++;
+}
+
+static unsigned int spi_engine_get_config(struct spi_device *spi)
+{
+	unsigned int config = 0;
+
+	if (spi->mode & SPI_CPOL)
+		config |= SPI_ENGINE_CONFIG_CPOL;
+	if (spi->mode & SPI_CPHA)
+		config |= SPI_ENGINE_CONFIG_CPHA;
+	if (spi->mode & SPI_3WIRE)
+		config |= SPI_ENGINE_CONFIG_3WIRE;
+
+	return config;
+}
+
+static unsigned int spi_engine_get_clk_div(struct spi_engine *spi_engine,
+	struct spi_device *spi, struct spi_transfer *xfer)
+{
+	unsigned int clk_div;
+
+	clk_div = DIV_ROUND_UP(clk_get_rate(spi_engine->ref_clk),
+		xfer->speed_hz * 2);
+	if (clk_div > 255)
+		clk_div = 255;
+	else if (clk_div > 0)
+		clk_div -= 1;
+
+	return clk_div;
+}
+
+static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry,
+	struct spi_transfer *xfer)
+{
+	unsigned int len = xfer->len;
+
+	while (len) {
+		unsigned int n = min(len, 256U);
+		unsigned int flags = 0;
+
+		if (xfer->tx_buf)
+			flags |= SPI_ENGINE_TRANSFER_WRITE;
+		if (xfer->rx_buf)
+			flags |= SPI_ENGINE_TRANSFER_READ;
+
+		spi_engine_program_add_cmd(p, dry,
+			SPI_ENGINE_CMD_TRANSFER(flags, n - 1));
+		len -= n;
+	}
+}
+
+static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry,
+	struct spi_engine *spi_engine, unsigned int clk_div, unsigned int delay)
+{
+	unsigned int spi_clk = clk_get_rate(spi_engine->ref_clk);
+	unsigned int t;
+
+	if (delay == 0)
+		return;
+
+	t = DIV_ROUND_UP(delay * spi_clk, (clk_div + 1) * 2);
+	while (t) {
+		unsigned int n = min(t, 256U);
+
+		spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_SLEEP(n - 1));
+		t -= n;
+	}
+}
+
+static void spi_engine_gen_cs(struct spi_engine_program *p, bool dry,
+		struct spi_device *spi, bool assert)
+{
+	unsigned int mask = 0xff;
+
+	if (assert)
+		mask ^= BIT(spi->chip_select);
+
+	spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_ASSERT(1, mask));
+}
+
+static int spi_engine_compile_message(struct spi_engine *spi_engine,
+	struct spi_message *msg, bool dry, struct spi_engine_program *p)
+{
+	struct spi_device *spi = msg->spi;
+	struct spi_transfer *xfer;
+	int clk_div, new_clk_div;
+	bool cs_change = true;
+
+	clk_div = -1;
+
+	spi_engine_program_add_cmd(p, dry,
+		SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CONFIG,
+			spi_engine_get_config(spi)));
+
+	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+		new_clk_div = spi_engine_get_clk_div(spi_engine, spi, xfer);
+		if (new_clk_div != clk_div) {
+			clk_div = new_clk_div;
+			spi_engine_program_add_cmd(p, dry,
+				SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV,
+					clk_div));
+		}
+
+		if (cs_change)
+			spi_engine_gen_cs(p, dry, spi, true);
+
+		spi_engine_gen_xfer(p, dry, xfer);
+		spi_engine_gen_sleep(p, dry, spi_engine, clk_div,
+			xfer->delay_usecs);
+
+		cs_change = xfer->cs_change;
+		if (list_is_last(&xfer->transfer_list, &msg->transfers))
+			cs_change = !cs_change;
+
+		if (cs_change)
+			spi_engine_gen_cs(p, dry, spi, false);
+	}
+
+	return 0;
+}
+
+static void spi_engine_xfer_next(struct spi_engine *spi_engine,
+	struct spi_transfer **_xfer)
+{
+	struct spi_message *msg = spi_engine->msg;
+	struct spi_transfer *xfer = *_xfer;
+
+	if (!xfer) {
+		xfer = list_first_entry(&msg->transfers,
+			struct spi_transfer, transfer_list);
+	} else if (list_is_last(&xfer->transfer_list, &msg->transfers)) {
+		xfer = NULL;
+	} else {
+		xfer = list_next_entry(xfer, transfer_list);
+	}
+
+	*_xfer = xfer;
+}
+
+static void spi_engine_tx_next(struct spi_engine *spi_engine)
+{
+	struct spi_transfer *xfer = spi_engine->tx_xfer;
+
+	do {
+		spi_engine_xfer_next(spi_engine, &xfer);
+	} while (xfer && !xfer->tx_buf);
+
+	spi_engine->tx_xfer = xfer;
+	if (xfer) {
+		spi_engine->tx_length = xfer->len;
+		spi_engine->tx_buf = xfer->tx_buf;
+	} else {
+		spi_engine->tx_buf = NULL;
+	}
+}
+
+static void spi_engine_rx_next(struct spi_engine *spi_engine)
+{
+	struct spi_transfer *xfer = spi_engine->rx_xfer;
+
+	do {
+		spi_engine_xfer_next(spi_engine, &xfer);
+	} while (xfer && !xfer->rx_buf);
+
+	spi_engine->rx_xfer = xfer;
+	if (xfer) {
+		spi_engine->rx_length = xfer->len;
+		spi_engine->rx_buf = xfer->rx_buf;
+	} else {
+		spi_engine->rx_buf = NULL;
+	}
+}
+
+static bool spi_engine_write_cmd_fifo(struct spi_engine *spi_engine)
+{
+	void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_CMD_FIFO;
+	unsigned int n, m, i;
+	const uint16_t *buf;
+
+	n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_CMD_FIFO_ROOM);
+	while (n && spi_engine->cmd_length) {
+		m = min(n, spi_engine->cmd_length);
+		buf = spi_engine->cmd_buf;
+		for (i = 0; i < m; i++)
+			writel_relaxed(buf[i], addr);
+		spi_engine->cmd_buf += m;
+		spi_engine->cmd_length -= m;
+		n -= m;
+	}
+
+	return spi_engine->cmd_length != 0;
+}
+
+static bool spi_engine_write_tx_fifo(struct spi_engine *spi_engine)
+{
+	void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDO_DATA_FIFO;
+	unsigned int n, m, i;
+	const uint8_t *buf;
+
+	n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDO_FIFO_ROOM);
+	while (n && spi_engine->tx_length) {
+		m = min(n, spi_engine->tx_length);
+		buf = spi_engine->tx_buf;
+		for (i = 0; i < m; i++)
+			writel_relaxed(buf[i], addr);
+		spi_engine->tx_buf += m;
+		spi_engine->tx_length -= m;
+		n -= m;
+		if (spi_engine->tx_length == 0)
+			spi_engine_tx_next(spi_engine);
+	}
+
+	return spi_engine->tx_length != 0;
+}
+
+static bool spi_engine_read_rx_fifo(struct spi_engine *spi_engine)
+{
+	void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDI_DATA_FIFO;
+	unsigned int n, m, i;
+	uint8_t *buf;
+
+	n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDI_FIFO_LEVEL);
+	while (n && spi_engine->rx_length) {
+		m = min(n, spi_engine->rx_length);
+		buf = spi_engine->rx_buf;
+		for (i = 0; i < m; i++)
+			buf[i] = readl_relaxed(addr);
+		spi_engine->rx_buf += m;
+		spi_engine->rx_length -= m;
+		n -= m;
+		if (spi_engine->rx_length == 0)
+			spi_engine_rx_next(spi_engine);
+	}
+
+	return spi_engine->rx_length != 0;
+}
+
+static irqreturn_t spi_engine_irq(int irq, void *devid)
+{
+	struct spi_master *master = devid;
+	struct spi_engine *spi_engine = spi_master_get_devdata(master);
+	unsigned int disable_int = 0;
+	unsigned int pending;
+
+	pending = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
+
+	if (pending & SPI_ENGINE_INT_SYNC) {
+		writel_relaxed(SPI_ENGINE_INT_SYNC,
+			spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
+		spi_engine->completed_id = readl_relaxed(
+			spi_engine->base + SPI_ENGINE_REG_SYNC_ID);
+	}
+
+	spin_lock(&spi_engine->lock);
+
+	if (pending & SPI_ENGINE_INT_CMD_ALMOST_EMPTY) {
+		if (!spi_engine_write_cmd_fifo(spi_engine))
+			disable_int |= SPI_ENGINE_INT_CMD_ALMOST_EMPTY;
+	}
+
+	if (pending & SPI_ENGINE_INT_SDO_ALMOST_EMPTY) {
+		if (!spi_engine_write_tx_fifo(spi_engine))
+			disable_int |= SPI_ENGINE_INT_SDO_ALMOST_EMPTY;
+	}
+
+	if (pending & (SPI_ENGINE_INT_SDI_ALMOST_FULL | SPI_ENGINE_INT_SYNC)) {
+		if (!spi_engine_read_rx_fifo(spi_engine))
+			disable_int |= SPI_ENGINE_INT_SDI_ALMOST_FULL;
+	}
+
+	if (pending & SPI_ENGINE_INT_SYNC) {
+		if (spi_engine->msg &&
+		    spi_engine->completed_id == spi_engine->sync_id) {
+			struct spi_message *msg = spi_engine->msg;
+
+			kfree(spi_engine->p);
+			msg->status = 0;
+			msg->actual_length = msg->frame_length;
+			spi_engine->msg = NULL;
+			spi_finalize_current_message(master);
+			disable_int |= SPI_ENGINE_INT_SYNC;
+		}
+	}
+
+	if (disable_int) {
+		spi_engine->int_enable &= ~disable_int;
+		writel_relaxed(spi_engine->int_enable,
+			spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
+	}
+
+	spin_unlock(&spi_engine->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int spi_engine_transfer_one_message(struct spi_master *master,
+	struct spi_message *msg)
+{
+	struct spi_engine_program p_dry, *p;
+	struct spi_engine *spi_engine = spi_master_get_devdata(master);
+	unsigned int int_enable = 0;
+	unsigned long flags;
+	size_t size;
+
+	p_dry.length = 0;
+	spi_engine_compile_message(spi_engine, msg, true, &p_dry);
+
+	size = sizeof(*p->instructions) * (p_dry.length + 1);
+	p = kzalloc(sizeof(*p) + size, GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+	spi_engine_compile_message(spi_engine, msg, false, p);
+
+	spin_lock_irqsave(&spi_engine->lock, flags);
+	spi_engine->sync_id = (spi_engine->sync_id + 1) & 0xff;
+	spi_engine_program_add_cmd(p, false,
+		SPI_ENGINE_CMD_SYNC(spi_engine->sync_id));
+
+	spi_engine->msg = msg;
+	spi_engine->p = p;
+
+	spi_engine->cmd_buf = p->instructions;
+	spi_engine->cmd_length = p->length;
+	if (spi_engine_write_cmd_fifo(spi_engine))
+		int_enable |= SPI_ENGINE_INT_CMD_ALMOST_EMPTY;
+
+	spi_engine_tx_next(spi_engine);
+	if (spi_engine_write_tx_fifo(spi_engine))
+		int_enable |= SPI_ENGINE_INT_SDO_ALMOST_EMPTY;
+
+	spi_engine_rx_next(spi_engine);
+	if (spi_engine->rx_length != 0)
+		int_enable |= SPI_ENGINE_INT_SDI_ALMOST_FULL;
+
+	int_enable |= SPI_ENGINE_INT_SYNC;
+
+	writel_relaxed(int_enable,
+		spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
+	spi_engine->int_enable = int_enable;
+	spin_unlock_irqrestore(&spi_engine->lock, flags);
+
+	return 0;
+}
+
+static int spi_engine_probe(struct platform_device *pdev)
+{
+	struct spi_engine *spi_engine;
+	struct spi_master *master;
+	unsigned int version;
+	struct resource *res;
+	int irq;
+	int ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0)
+		return -ENXIO;
+
+	spi_engine = devm_kzalloc(&pdev->dev, sizeof(*spi_engine), GFP_KERNEL);
+	if (!spi_engine)
+		return -ENOMEM;
+
+	master = spi_alloc_master(&pdev->dev, 0);
+	if (!master)
+		return -ENOMEM;
+
+	spi_master_set_devdata(master, spi_engine);
+
+	spin_lock_init(&spi_engine->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	spi_engine->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(spi_engine->base)) {
+		ret = PTR_ERR(spi_engine->base);
+		goto err_put_master;
+	}
+
+	version = readl(spi_engine->base + SPI_ENGINE_REG_VERSION);
+	if (SPI_ENGINE_VERSION_MAJOR(version) != 1) {
+		dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%c\n",
+			SPI_ENGINE_VERSION_MAJOR(version),
+			SPI_ENGINE_VERSION_MINOR(version),
+			SPI_ENGINE_VERSION_PATCH(version));
+		return -ENODEV;
+	}
+
+	spi_engine->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
+	if (IS_ERR(spi_engine->clk)) {
+		ret = PTR_ERR(spi_engine->clk);
+		goto err_put_master;
+	}
+
+	spi_engine->ref_clk = devm_clk_get(&pdev->dev, "spi_clk");
+	if (IS_ERR(spi_engine->ref_clk)) {
+		ret = PTR_ERR(spi_engine->ref_clk);
+		goto err_put_master;
+	}
+
+	ret = clk_prepare_enable(spi_engine->clk);
+	if (ret)
+		goto err_put_master;
+
+	ret = clk_prepare_enable(spi_engine->ref_clk);
+	if (ret)
+		goto err_clk_disable;
+
+	writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET);
+	writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
+	writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
+
+	ret = request_irq(irq, spi_engine_irq, 0, pdev->name, master);
+	if (ret)
+		goto err_ref_clk_disable;
+
+	master->dev.parent = &pdev->dev;
+	master->dev.of_node = pdev->dev.of_node;
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_3WIRE;
+	master->bits_per_word_mask = SPI_BPW_MASK(8);
+	master->max_speed_hz = clk_get_rate(spi_engine->ref_clk) / 2;
+	master->transfer_one_message = spi_engine_transfer_one_message;
+	master->num_chipselect = 8;
+
+	ret = spi_register_master(master);
+	if (ret)
+		goto err_free_irq;
+
+	platform_set_drvdata(pdev, master);
+
+	return 0;
+err_free_irq:
+	free_irq(irq, master);
+err_ref_clk_disable:
+	clk_disable_unprepare(spi_engine->ref_clk);
+err_clk_disable:
+	clk_disable_unprepare(spi_engine->clk);
+err_put_master:
+	spi_master_put(master);
+	return ret;
+}
+
+static int spi_engine_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = platform_get_drvdata(pdev);
+	struct spi_engine *spi_engine = spi_master_get_devdata(master);
+	int irq = platform_get_irq(pdev, 0);
+
+	spi_unregister_master(master);
+
+	free_irq(irq, master);
+
+	writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
+	writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
+	writel_relaxed(0x01, spi_engine->base + SPI_ENGINE_REG_RESET);
+
+	clk_disable_unprepare(spi_engine->ref_clk);
+	clk_disable_unprepare(spi_engine->clk);
+
+	return 0;
+}
+
+static const struct of_device_id spi_engine_match_table[] = {
+	{ .compatible = "adi,axi-spi-engine-1.00.a" },
+	{ },
+};
+
+static struct platform_driver spi_engine_driver = {
+	.probe = spi_engine_probe,
+	.remove = spi_engine_remove,
+	.driver = {
+		.name = "spi-engine",
+		.of_match_table = spi_engine_match_table,
+	},
+};
+module_platform_driver(spi_engine_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Analog Devices SPI engine peripheral driver");
+MODULE_LICENSE("GPL");

drivers/spi/spi-bcm2835.c

@@ -727,11 +727,6 @@ static int bcm2835_spi_setup(struct spi_device *spi)
 			spi->chip_select, spi->cs_gpio, err);
 		return err;
 	}
-	/* the implementation of pinctrl-bcm2835 currently does not
-	 * set the GPIO value when using gpio_direction_output
-	 * so we are setting it here explicitly
-	 */
-	gpio_set_value(spi->cs_gpio, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
 
 	return 0;
 }

drivers/spi/spi-bcm2835aux.c

@@ -64,9 +64,9 @@
 #define BCM2835_AUX_SPI_CNTL0_VAR_WIDTH	0x00004000
 #define BCM2835_AUX_SPI_CNTL0_DOUTHOLD	0x00003000
 #define BCM2835_AUX_SPI_CNTL0_ENABLE	0x00000800
-#define BCM2835_AUX_SPI_CNTL0_CPHA_IN	0x00000400
+#define BCM2835_AUX_SPI_CNTL0_IN_RISING	0x00000400
 #define BCM2835_AUX_SPI_CNTL0_CLEARFIFO	0x00000200
-#define BCM2835_AUX_SPI_CNTL0_CPHA_OUT	0x00000100
+#define BCM2835_AUX_SPI_CNTL0_OUT_RISING	0x00000100
 #define BCM2835_AUX_SPI_CNTL0_CPOL	0x00000080
 #define BCM2835_AUX_SPI_CNTL0_MSBF_OUT	0x00000040
 #define BCM2835_AUX_SPI_CNTL0_SHIFTLEN	0x0000003F
@@ -92,9 +92,6 @@
 #define BCM2835_AUX_SPI_POLLING_LIMIT_US	30
 #define BCM2835_AUX_SPI_POLLING_JIFFIES		2
 
-#define BCM2835_AUX_SPI_MODE_BITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
-				  | SPI_NO_CS)
-
 struct bcm2835aux_spi {
 	void __iomem *regs;
 	struct clk *clk;
@@ -212,9 +209,15 @@ static irqreturn_t bcm2835aux_spi_interrupt(int irq, void *dev_id)
 		ret = IRQ_HANDLED;
 	}
 
-	/* and if rx_len is 0 then wake up completion and disable spi */
+	if (!bs->tx_len) {
+		/* disable tx fifo empty interrupt */
+		bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL1, bs->cntl[1] |
+			BCM2835_AUX_SPI_CNTL1_IDLE);
+	}
+
+	/* and if rx_len is 0 then disable interrupts and wake up completion */
 	if (!bs->rx_len) {
-		bcm2835aux_spi_reset_hw(bs);
+		bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL1, bs->cntl[1]);
 		complete(&master->xfer_completion);
 	}
 
@@ -307,9 +310,6 @@ static int bcm2835aux_spi_transfer_one_poll(struct spi_master *master,
 		}
 	}
 
-	/* Transfer complete - reset SPI HW */
-	bcm2835aux_spi_reset_hw(bs);
-
 	/* and return without waiting for completion */
 	return 0;
 }
@@ -330,10 +330,6 @@ static int bcm2835aux_spi_transfer_one(struct spi_master *master,
 	 * resulting (potentially) in more interrupts when transferring
 	 * more than 12 bytes
 	 */
-	bs->cntl[0] = BCM2835_AUX_SPI_CNTL0_ENABLE |
-		      BCM2835_AUX_SPI_CNTL0_VAR_WIDTH |
-		      BCM2835_AUX_SPI_CNTL0_MSBF_OUT;
-	bs->cntl[1] = BCM2835_AUX_SPI_CNTL1_MSBF_IN;
 
 	/* set clock */
 	spi_hz = tfr->speed_hz;
@@ -348,17 +344,13 @@ static int bcm2835aux_spi_transfer_one(struct spi_master *master,
 	} else { /* the slowest we can go */
 		speed = BCM2835_AUX_SPI_CNTL0_SPEED_MAX;
 	}
+	/* mask out old speed from previous spi_transfer */
+	bs->cntl[0] &= ~(BCM2835_AUX_SPI_CNTL0_SPEED);
+	/* set the new speed */
 	bs->cntl[0] |= speed << BCM2835_AUX_SPI_CNTL0_SPEED_SHIFT;
 
 	spi_used_hz = clk_hz / (2 * (speed + 1));
 
-	/* handle all the modes */
-	if (spi->mode & SPI_CPOL)
-		bs->cntl[0] |= BCM2835_AUX_SPI_CNTL0_CPOL;
-	if (spi->mode & SPI_CPHA)
-		bs->cntl[0] |= BCM2835_AUX_SPI_CNTL0_CPHA_OUT |
-			       BCM2835_AUX_SPI_CNTL0_CPHA_IN;
-
 	/* set transmit buffers and length */
 	bs->tx_buf = tfr->tx_buf;
 	bs->rx_buf = tfr->rx_buf;
@@ -382,6 +374,40 @@ static int bcm2835aux_spi_transfer_one(struct spi_master *master,
 	return bcm2835aux_spi_transfer_one_irq(master, spi, tfr);
 }
 
+static int bcm2835aux_spi_prepare_message(struct spi_master *master,
+					  struct spi_message *msg)
+{
+	struct spi_device *spi = msg->spi;
+	struct bcm2835aux_spi *bs = spi_master_get_devdata(master);
+
+	bs->cntl[0] = BCM2835_AUX_SPI_CNTL0_ENABLE |
+		      BCM2835_AUX_SPI_CNTL0_VAR_WIDTH |
+		      BCM2835_AUX_SPI_CNTL0_MSBF_OUT;
+	bs->cntl[1] = BCM2835_AUX_SPI_CNTL1_MSBF_IN;
+
+	/* handle all the modes */
+	if (spi->mode & SPI_CPOL) {
+		bs->cntl[0] |= BCM2835_AUX_SPI_CNTL0_CPOL;
+		bs->cntl[0] |= BCM2835_AUX_SPI_CNTL0_OUT_RISING;
+	} else {
+		bs->cntl[0] |= BCM2835_AUX_SPI_CNTL0_IN_RISING;
+	}
+	bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL1, bs->cntl[1]);
+	bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL0, bs->cntl[0]);
+
+	return 0;
+}
+
+static int bcm2835aux_spi_unprepare_message(struct spi_master *master,
+					    struct spi_message *msg)
+{
+	struct bcm2835aux_spi *bs = spi_master_get_devdata(master);
+
+	bcm2835aux_spi_reset_hw(bs);
+
+	return 0;
+}
+
 static void bcm2835aux_spi_handle_err(struct spi_master *master,
 				      struct spi_message *msg)
 {
@@ -405,11 +431,13 @@ static int bcm2835aux_spi_probe(struct platform_device *pdev)
 	}
 
 	platform_set_drvdata(pdev, master);
-	master->mode_bits = BCM2835_AUX_SPI_MODE_BITS;
+	master->mode_bits = (SPI_CPOL | SPI_CS_HIGH | SPI_NO_CS);
 	master->bits_per_word_mask = SPI_BPW_MASK(8);
 	master->num_chipselect = -1;
 	master->transfer_one = bcm2835aux_spi_transfer_one;
 	master->handle_err = bcm2835aux_spi_handle_err;
+	master->prepare_message = bcm2835aux_spi_prepare_message;
+	master->unprepare_message = bcm2835aux_spi_unprepare_message;
 	master->dev.of_node = pdev->dev.of_node;
 
 	bs = spi_master_get_devdata(master);

drivers/spi/spi-dw-mid.c

@@ -89,10 +89,10 @@ static void mid_spi_dma_exit(struct dw_spi *dws)
 	if (!dws->dma_inited)
 		return;
 
-	dmaengine_terminate_all(dws->txchan);
+	dmaengine_terminate_sync(dws->txchan);
 	dma_release_channel(dws->txchan);
 
-	dmaengine_terminate_all(dws->rxchan);
+	dmaengine_terminate_sync(dws->rxchan);
 	dma_release_channel(dws->rxchan);
 }
 

drivers/spi/spi-dw-mmio.c

@@ -47,11 +47,6 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
 
 	/* Get basic io resource and map it */
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!mem) {
-		dev_err(&pdev->dev, "no mem resource?\n");
-		return -EINVAL;
-	}
-
 	dws->regs = devm_ioremap_resource(&pdev->dev, mem);
 	if (IS_ERR(dws->regs)) {
 		dev_err(&pdev->dev, "SPI region map failed\n");

drivers/spi/spi-imx.c

@@ -56,7 +56,6 @@
 
 /* The maximum  bytes that a sdma BD can transfer.*/
 #define MAX_SDMA_BD_BYTES  (1 << 15)
-#define IMX_DMA_TIMEOUT (msecs_to_jiffies(3000))
 struct spi_imx_config {
 	unsigned int speed_hz;
 	unsigned int bpw;
@@ -86,12 +85,18 @@ struct spi_imx_devtype_data {
 
 struct spi_imx_data {
 	struct spi_bitbang bitbang;
+	struct device *dev;
 
 	struct completion xfer_done;
 	void __iomem *base;
+	unsigned long base_phys;
+
 	struct clk *clk_per;
 	struct clk *clk_ipg;
 	unsigned long spi_clk;
+	unsigned int spi_bus_clk;
+
+	unsigned int bytes_per_word;
 
 	unsigned int count;
 	void (*tx)(struct spi_imx_data *);
@@ -101,8 +106,6 @@ struct spi_imx_data {
 	unsigned int txfifo; /* number of words pushed in tx FIFO */
 
 	/* DMA */
-	unsigned int dma_is_inited;
-	unsigned int dma_finished;
 	bool usedma;
 	u32 wml;
 	struct completion dma_rx_completion;
@@ -199,15 +202,35 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin,
 	return 7;
 }
 
+static int spi_imx_bytes_per_word(const int bpw)
+{
+	return DIV_ROUND_UP(bpw, BITS_PER_BYTE);
+}
+
 static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 			 struct spi_transfer *transfer)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+	unsigned int bpw = transfer->bits_per_word;
+
+	if (!master->dma_rx)
+		return false;
 
-	if (spi_imx->dma_is_inited && transfer->len >= spi_imx->wml &&
-	    (transfer->len % spi_imx->wml) == 0)
-		return true;
-	return false;
+	if (!bpw)
+		bpw = spi->bits_per_word;
+
+	bpw = spi_imx_bytes_per_word(bpw);
+
+	if (bpw != 1 && bpw != 2 && bpw != 4)
+		return false;
+
+	if (transfer->len < spi_imx->wml * bpw)
+		return false;
+
+	if (transfer->len % (spi_imx->wml * bpw))
+		return false;
+
+	return true;
 }
 
 #define MX51_ECSPI_CTRL		0x08
@@ -232,16 +255,13 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 #define MX51_ECSPI_INT_RREN		(1 <<  3)
 
 #define MX51_ECSPI_DMA      0x14
-#define MX51_ECSPI_DMA_TX_WML_OFFSET	0
-#define MX51_ECSPI_DMA_TX_WML_MASK	0x3F
-#define MX51_ECSPI_DMA_RX_WML_OFFSET	16
-#define MX51_ECSPI_DMA_RX_WML_MASK	(0x3F << 16)
-#define MX51_ECSPI_DMA_RXT_WML_OFFSET	24
-#define MX51_ECSPI_DMA_RXT_WML_MASK	(0x3F << 24)
+#define MX51_ECSPI_DMA_TX_WML(wml)	((wml) & 0x3f)
+#define MX51_ECSPI_DMA_RX_WML(wml)	(((wml) & 0x3f) << 16)
+#define MX51_ECSPI_DMA_RXT_WML(wml)	(((wml) & 0x3f) << 24)
 
-#define MX51_ECSPI_DMA_TEDEN_OFFSET	7
-#define MX51_ECSPI_DMA_RXDEN_OFFSET	23
-#define MX51_ECSPI_DMA_RXTDEN_OFFSET	31
+#define MX51_ECSPI_DMA_TEDEN		(1 << 7)
+#define MX51_ECSPI_DMA_RXDEN		(1 << 23)
+#define MX51_ECSPI_DMA_RXTDEN		(1 << 31)
 
 #define MX51_ECSPI_STAT		0x18
 #define MX51_ECSPI_STAT_RR		(1 <<  3)
@@ -250,14 +270,15 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 #define MX51_ECSPI_TESTREG_LBC	BIT(31)
 
 /* MX51 eCSPI */
-static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi,
-				      unsigned int *fres)
+static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx,
+				      unsigned int fspi, unsigned int *fres)
 {
 	/*
 	 * there are two 4-bit dividers, the pre-divider divides by
 	 * $pre, the post-divider by 2^$post
 	 */
 	unsigned int pre, post;
+	unsigned int fin = spi_imx->spi_clk;
 
 	if (unlikely(fspi > fin))
 		return 0;
@@ -270,14 +291,14 @@ static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi,
 
 	post = max(4U, post) - 4;
 	if (unlikely(post > 0xf)) {
-		pr_err("%s: cannot set clock freq: %u (base freq: %u)\n",
-				__func__, fspi, fin);
+		dev_err(spi_imx->dev, "cannot set clock freq: %u (base freq: %u)\n",
+				fspi, fin);
 		return 0xff;
 	}
 
 	pre = DIV_ROUND_UP(fin, fspi << post) - 1;
 
-	pr_debug("%s: fin: %u, fspi: %u, post: %u, pre: %u\n",
+	dev_dbg(spi_imx->dev, "%s: fin: %u, fspi: %u, post: %u, pre: %u\n",
 			__func__, fin, fspi, post, pre);
 
 	/* Resulting frequency for the SCLK line. */
@@ -302,22 +323,17 @@ static void __maybe_unused mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int
 
 static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
 {
-	u32 reg = readl(spi_imx->base + MX51_ECSPI_CTRL);
+	u32 reg;
 
-	if (!spi_imx->usedma)
-		reg |= MX51_ECSPI_CTRL_XCH;
-	else if (!spi_imx->dma_finished)
-		reg |= MX51_ECSPI_CTRL_SMC;
-	else
-		reg &= ~MX51_ECSPI_CTRL_SMC;
+	reg = readl(spi_imx->base + MX51_ECSPI_CTRL);
+	reg |= MX51_ECSPI_CTRL_XCH;
 	writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
 }
 
 static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
 		struct spi_imx_config *config)
 {
-	u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0;
-	u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg;
+	u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0;
 	u32 clk = config->speed_hz, delay, reg;
 
 	/*
@@ -330,7 +346,8 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
 	ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
 
 	/* set clock speed */
-	ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz, &clk);
+	ctrl |= mx51_ecspi_clkdiv(spi_imx, config->speed_hz, &clk);
+	spi_imx->spi_bus_clk = clk;
 
 	/* set chip select to use */
 	ctrl |= MX51_ECSPI_CTRL_CS(config->cs);
@@ -341,20 +358,16 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
 
 	if (config->mode & SPI_CPHA)
 		cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs);
-	else
-		cfg &= ~MX51_ECSPI_CONFIG_SCLKPHA(config->cs);
 
 	if (config->mode & SPI_CPOL) {
 		cfg |= MX51_ECSPI_CONFIG_SCLKPOL(config->cs);
 		cfg |= MX51_ECSPI_CONFIG_SCLKCTL(config->cs);
-	} else {
-		cfg &= ~MX51_ECSPI_CONFIG_SCLKPOL(config->cs);
-		cfg &= ~MX51_ECSPI_CONFIG_SCLKCTL(config->cs);
 	}
 	if (config->mode & SPI_CS_HIGH)
 		cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs);
-	else
-		cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(config->cs);
+
+	if (spi_imx->usedma)
+		ctrl |= MX51_ECSPI_CTRL_SMC;
 
 	/* CTRL register always go first to bring out controller from reset */
 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
@@ -389,22 +402,12 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
 	 * Configure the DMA register: setup the watermark
 	 * and enable DMA request.
 	 */
-	if (spi_imx->dma_is_inited) {
-		dma = readl(spi_imx->base + MX51_ECSPI_DMA);
-
-		rx_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_RX_WML_OFFSET;
-		tx_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_TX_WML_OFFSET;
-		rxt_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_RXT_WML_OFFSET;
-		dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK
-			   & ~MX51_ECSPI_DMA_RX_WML_MASK
-			   & ~MX51_ECSPI_DMA_RXT_WML_MASK)
-			   | rx_wml_cfg | tx_wml_cfg | rxt_wml_cfg
-			   |(1 << MX51_ECSPI_DMA_TEDEN_OFFSET)
-			   |(1 << MX51_ECSPI_DMA_RXDEN_OFFSET)
-			   |(1 << MX51_ECSPI_DMA_RXTDEN_OFFSET);
-
-		writel(dma, spi_imx->base + MX51_ECSPI_DMA);
-	}
+
+	writel(MX51_ECSPI_DMA_RX_WML(spi_imx->wml) |
+		MX51_ECSPI_DMA_TX_WML(spi_imx->wml) |
+		MX51_ECSPI_DMA_RXT_WML(spi_imx->wml) |
+		MX51_ECSPI_DMA_TEDEN | MX51_ECSPI_DMA_RXDEN |
+		MX51_ECSPI_DMA_RXTDEN, spi_imx->base + MX51_ECSPI_DMA);
 
 	return 0;
 }
@@ -784,11 +787,63 @@ static irqreturn_t spi_imx_isr(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static int spi_imx_dma_configure(struct spi_master *master,
+				 int bytes_per_word)
+{
+	int ret;
+	enum dma_slave_buswidth buswidth;
+	struct dma_slave_config rx = {}, tx = {};
+	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
+
+	if (bytes_per_word == spi_imx->bytes_per_word)
+		/* Same as last time */
+		return 0;
+
+	switch (bytes_per_word) {
+	case 4:
+		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
+		break;
+	case 2:
+		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
+		break;
+	case 1:
+		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	tx.direction = DMA_MEM_TO_DEV;
+	tx.dst_addr = spi_imx->base_phys + MXC_CSPITXDATA;
+	tx.dst_addr_width = buswidth;
+	tx.dst_maxburst = spi_imx->wml;
+	ret = dmaengine_slave_config(master->dma_tx, &tx);
+	if (ret) {
+		dev_err(spi_imx->dev, "TX dma configuration failed with %d\n", ret);
+		return ret;
+	}
+
+	rx.direction = DMA_DEV_TO_MEM;
+	rx.src_addr = spi_imx->base_phys + MXC_CSPIRXDATA;
+	rx.src_addr_width = buswidth;
+	rx.src_maxburst = spi_imx->wml;
+	ret = dmaengine_slave_config(master->dma_rx, &rx);
+	if (ret) {
+		dev_err(spi_imx->dev, "RX dma configuration failed with %d\n", ret);
+		return ret;
+	}
+
+	spi_imx->bytes_per_word = bytes_per_word;
+
+	return 0;
+}
+
 static int spi_imx_setupxfer(struct spi_device *spi,
 				 struct spi_transfer *t)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
 	struct spi_imx_config config;
+	int ret;
 
 	config.bpw = t ? t->bits_per_word : spi->bits_per_word;
 	config.speed_hz  = t ? t->speed_hz : spi->max_speed_hz;
@@ -812,6 +867,18 @@ static int spi_imx_setupxfer(struct spi_device *spi,
 		spi_imx->tx = spi_imx_buf_tx_u32;
 	}
 
+	if (spi_imx_can_dma(spi_imx->bitbang.master, spi, t))
+		spi_imx->usedma = 1;
+	else
+		spi_imx->usedma = 0;
+
+	if (spi_imx->usedma) {
+		ret = spi_imx_dma_configure(spi->master,
+					    spi_imx_bytes_per_word(config.bpw));
+		if (ret)
+			return ret;
+	}
+
 	spi_imx->devtype_data->config(spi_imx, &config);
 
 	return 0;
@@ -830,15 +897,11 @@ static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx)
 		dma_release_channel(master->dma_tx);
 		master->dma_tx = NULL;
 	}
-
-	spi_imx->dma_is_inited = 0;
 }
 
 static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
-			     struct spi_master *master,
-			     const struct resource *res)
+			     struct spi_master *master)
 {
-	struct dma_slave_config slave_config = {};
 	int ret;
 
 	/* use pio mode for i.mx6dl chip TKT238285 */
@@ -856,16 +919,6 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 		goto err;
 	}
 
-	slave_config.direction = DMA_MEM_TO_DEV;
-	slave_config.dst_addr = res->start + MXC_CSPITXDATA;
-	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-	slave_config.dst_maxburst = spi_imx->wml;
-	ret = dmaengine_slave_config(master->dma_tx, &slave_config);
-	if (ret) {
-		dev_err(dev, "error in TX dma configuration.\n");
-		goto err;
-	}
-
 	/* Prepare for RX : */
 	master->dma_rx = dma_request_slave_channel_reason(dev, "rx");
 	if (IS_ERR(master->dma_rx)) {
@@ -875,15 +928,7 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 		goto err;
 	}
 
-	slave_config.direction = DMA_DEV_TO_MEM;
-	slave_config.src_addr = res->start + MXC_CSPIRXDATA;
-	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-	slave_config.src_maxburst = spi_imx->wml;
-	ret = dmaengine_slave_config(master->dma_rx, &slave_config);
-	if (ret) {
-		dev_err(dev, "error in RX dma configuration.\n");
-		goto err;
-	}
+	spi_imx_dma_configure(master, 1);
 
 	init_completion(&spi_imx->dma_rx_completion);
 	init_completion(&spi_imx->dma_tx_completion);
@@ -891,7 +936,6 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	master->max_dma_len = MAX_SDMA_BD_BYTES;
 	spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX |
 					 SPI_MASTER_MUST_TX;
-	spi_imx->dma_is_inited = 1;
 
 	return 0;
 err:
@@ -913,95 +957,81 @@ static void spi_imx_dma_tx_callback(void *cookie)
 	complete(&spi_imx->dma_tx_completion);
 }
 
+static int spi_imx_calculate_timeout(struct spi_imx_data *spi_imx, int size)
+{
+	unsigned long timeout = 0;
+
+	/* Time with actual data transfer and CS change delay related to HW */
+	timeout = (8 + 4) * size / spi_imx->spi_bus_clk;
+
+	/* Add extra second for scheduler related activities */
+	timeout += 1;
+
+	/* Double calculated timeout */
+	return msecs_to_jiffies(2 * timeout * MSEC_PER_SEC);
+}
+
 static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 				struct spi_transfer *transfer)
 {
-	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
-	int ret;
+	struct dma_async_tx_descriptor *desc_tx, *desc_rx;
+	unsigned long transfer_timeout;
 	unsigned long timeout;
 	struct spi_master *master = spi_imx->bitbang.master;
 	struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg;
 
-	if (tx) {
-		desc_tx = dmaengine_prep_slave_sg(master->dma_tx,
-					tx->sgl, tx->nents, DMA_MEM_TO_DEV,
-					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-		if (!desc_tx)
-			goto tx_nodma;
-
-		desc_tx->callback = spi_imx_dma_tx_callback;
-		desc_tx->callback_param = (void *)spi_imx;
-		dmaengine_submit(desc_tx);
-	}
+	/*
+	 * The TX DMA setup starts the transfer, so make sure RX is configured
+	 * before TX.
+	 */
+	desc_rx = dmaengine_prep_slave_sg(master->dma_rx,
+				rx->sgl, rx->nents, DMA_DEV_TO_MEM,
+				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc_rx)
+		return -EINVAL;
 
-	if (rx) {
-		desc_rx = dmaengine_prep_slave_sg(master->dma_rx,
-					rx->sgl, rx->nents, DMA_DEV_TO_MEM,
-					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-		if (!desc_rx)
-			goto rx_nodma;
+	desc_rx->callback = spi_imx_dma_rx_callback;
+	desc_rx->callback_param = (void *)spi_imx;
+	dmaengine_submit(desc_rx);
+	reinit_completion(&spi_imx->dma_rx_completion);
+	dma_async_issue_pending(master->dma_rx);
 
-		desc_rx->callback = spi_imx_dma_rx_callback;
-		desc_rx->callback_param = (void *)spi_imx;
-		dmaengine_submit(desc_rx);
+	desc_tx = dmaengine_prep_slave_sg(master->dma_tx,
+				tx->sgl, tx->nents, DMA_MEM_TO_DEV,
+				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc_tx) {
+		dmaengine_terminate_all(master->dma_tx);
+		return -EINVAL;
 	}
 
-	reinit_completion(&spi_imx->dma_rx_completion);
+	desc_tx->callback = spi_imx_dma_tx_callback;
+	desc_tx->callback_param = (void *)spi_imx;
+	dmaengine_submit(desc_tx);
 	reinit_completion(&spi_imx->dma_tx_completion);
-
-	/* Trigger the cspi module. */
-	spi_imx->dma_finished = 0;
-
-	/*
-	 * Set these order to avoid potential RX overflow. The overflow may
-	 * happen if we enable SPI HW before starting RX DMA due to rescheduling
-	 * for another task and/or interrupt.
-	 * So RX DMA enabled first to make sure data would be read out from FIFO
-	 * ASAP. TX DMA enabled next to start filling TX FIFO with new data.
-	 * And finaly SPI HW enabled to start actual data transfer.
-	 */
-	dma_async_issue_pending(master->dma_rx);
 	dma_async_issue_pending(master->dma_tx);
-	spi_imx->devtype_data->trigger(spi_imx);
+
+	transfer_timeout = spi_imx_calculate_timeout(spi_imx, transfer->len);
 
 	/* Wait SDMA to finish the data transfer.*/
 	timeout = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
-						IMX_DMA_TIMEOUT);
+						transfer_timeout);
 	if (!timeout) {
-		pr_warn("%s %s: I/O Error in DMA TX\n",
-			dev_driver_string(&master->dev),
-			dev_name(&master->dev));
+		dev_err(spi_imx->dev, "I/O Error in DMA TX\n");
 		dmaengine_terminate_all(master->dma_tx);
 		dmaengine_terminate_all(master->dma_rx);
-	} else {
-		timeout = wait_for_completion_timeout(
-				&spi_imx->dma_rx_completion, IMX_DMA_TIMEOUT);
-		if (!timeout) {
-			pr_warn("%s %s: I/O Error in DMA RX\n",
-				dev_driver_string(&master->dev),
-				dev_name(&master->dev));
-			spi_imx->devtype_data->reset(spi_imx);
-			dmaengine_terminate_all(master->dma_rx);
-		}
+		return -ETIMEDOUT;
 	}
 
-	spi_imx->dma_finished = 1;
-	spi_imx->devtype_data->trigger(spi_imx);
-
-	if (!timeout)
-		ret = -ETIMEDOUT;
-	else
-		ret = transfer->len;
-
-	return ret;
+	timeout = wait_for_completion_timeout(&spi_imx->dma_rx_completion,
+					      transfer_timeout);
+	if (!timeout) {
+		dev_err(&master->dev, "I/O Error in DMA RX\n");
+		spi_imx->devtype_data->reset(spi_imx);
+		dmaengine_terminate_all(master->dma_rx);
+		return -ETIMEDOUT;
+	}
 
-rx_nodma:
-	dmaengine_terminate_all(master->dma_tx);
-tx_nodma:
-	pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
-		     dev_driver_string(&master->dev),
-		     dev_name(&master->dev));
-	return -EAGAIN;
+	return transfer->len;
 }
 
 static int spi_imx_pio_transfer(struct spi_device *spi,
@@ -1028,19 +1058,12 @@ static int spi_imx_pio_transfer(struct spi_device *spi,
 static int spi_imx_transfer(struct spi_device *spi,
 				struct spi_transfer *transfer)
 {
-	int ret;
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
 
-	if (spi_imx->bitbang.master->can_dma &&
-	    spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) {
-		spi_imx->usedma = true;
-		ret = spi_imx_dma_transfer(spi_imx, transfer);
-		if (ret != -EAGAIN)
-			return ret;
-	}
-	spi_imx->usedma = false;
-
-	return spi_imx_pio_transfer(spi, transfer);
+	if (spi_imx->usedma)
+		return spi_imx_dma_transfer(spi_imx, transfer);
+	else
+		return spi_imx_pio_transfer(spi, transfer);
 }
 
 static int spi_imx_setup(struct spi_device *spi)
@@ -1130,6 +1153,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 
 	spi_imx = spi_master_get_devdata(master);
 	spi_imx->bitbang.master = master;
+	spi_imx->dev = &pdev->dev;
 
 	spi_imx->devtype_data = of_id ? of_id->data :
 		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;
@@ -1170,6 +1194,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 		ret = PTR_ERR(spi_imx->base);
 		goto out_master_put;
 	}
+	spi_imx->base_phys = res->start;
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
@@ -1210,7 +1235,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 	 * other chips.
 	 */
 	if (is_imx51_ecspi(spi_imx)) {
-		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master, res);
+		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master);
 		if (ret == -EPROBE_DEFER)
 			goto out_clk_put;
 

drivers/spi/spi-lp8841-rtc.c

+/*
+ * SPI master driver for ICP DAS LP-8841 RTC
+ *
+ * Copyright (C) 2016 Sergei Ianovich
+ *
+ * based on
+ *
+ * Dallas DS1302 RTC Support
+ * Copyright (C) 2002 David McCullough
+ * Copyright (C) 2003 - 2007 Paul Mundt
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/spi/spi.h>
+
+#define DRIVER_NAME	"spi_lp8841_rtc"
+
+#define SPI_LP8841_RTC_CE	0x01
+#define SPI_LP8841_RTC_CLK	0x02
+#define SPI_LP8841_RTC_nWE	0x04
+#define SPI_LP8841_RTC_MOSI	0x08
+#define SPI_LP8841_RTC_MISO	0x01
+
+/*
+ * REVISIT If there is support for SPI_3WIRE and SPI_LSB_FIRST in SPI
+ * GPIO driver, this SPI driver can be replaced by a simple GPIO driver
+ * providing 3 GPIO pins.
+ */
+
+struct spi_lp8841_rtc {
+	void		*iomem;
+	unsigned long	state;
+};
+
+static inline void
+setsck(struct spi_lp8841_rtc *data, int is_on)
+{
+	if (is_on)
+		data->state |= SPI_LP8841_RTC_CLK;
+	else
+		data->state &= ~SPI_LP8841_RTC_CLK;
+	writeb(data->state, data->iomem);
+}
+
+static inline void
+setmosi(struct spi_lp8841_rtc *data, int is_on)
+{
+	if (is_on)
+		data->state |= SPI_LP8841_RTC_MOSI;
+	else
+		data->state &= ~SPI_LP8841_RTC_MOSI;
+	writeb(data->state, data->iomem);
+}
+
+static inline int
+getmiso(struct spi_lp8841_rtc *data)
+{
+	return ioread8(data->iomem) & SPI_LP8841_RTC_MISO;
+}
+
+static inline u32
+bitbang_txrx_be_cpha0_lsb(struct spi_lp8841_rtc *data,
+		unsigned usecs, unsigned cpol, unsigned flags,
+		u32 word, u8 bits)
+{
+	/* if (cpol == 0) this is SPI_MODE_0; else this is SPI_MODE_2 */
+
+	u32 shift = 32 - bits;
+	/* clock starts at inactive polarity */
+	for (; likely(bits); bits--) {
+
+		/* setup LSB (to slave) on leading edge */
+		if ((flags & SPI_MASTER_NO_TX) == 0)
+			setmosi(data, (word & 1));
+
+		usleep_range(usecs, usecs + 1);	/* T(setup) */
+
+		/* sample LSB (from slave) on trailing edge */
+		word >>= 1;
+		if ((flags & SPI_MASTER_NO_RX) == 0)
+			word |= (getmiso(data) << 31);
+
+		setsck(data, !cpol);
+		usleep_range(usecs, usecs + 1);
+
+		setsck(data, cpol);
+	}
+
+	word >>= shift;
+	return word;
+}
+
+static int
+spi_lp8841_rtc_transfer_one(struct spi_master *master,
+			    struct spi_device *spi,
+			    struct spi_transfer *t)
+{
+	struct spi_lp8841_rtc	*data = spi_master_get_devdata(master);
+	unsigned		count = t->len;
+	const u8		*tx = t->tx_buf;
+	u8			*rx = t->rx_buf;
+	u8			word = 0;
+	int			ret = 0;
+
+	if (tx) {
+		data->state &= ~SPI_LP8841_RTC_nWE;
+		writeb(data->state, data->iomem);
+		while (likely(count > 0)) {
+			word = *tx++;
+			bitbang_txrx_be_cpha0_lsb(data, 1, 0,
+					SPI_MASTER_NO_RX, word, 8);
+			count--;
+		}
+	} else if (rx) {
+		data->state |= SPI_LP8841_RTC_nWE;
+		writeb(data->state, data->iomem);
+		while (likely(count > 0)) {
+			word = bitbang_txrx_be_cpha0_lsb(data, 1, 0,
+					SPI_MASTER_NO_TX, word, 8);
+			*rx++ = word;
+			count--;
+		}
+	} else {
+		ret = -EINVAL;
+	}
+
+	spi_finalize_current_transfer(master);
+
+	return ret;
+}
+
+static void
+spi_lp8841_rtc_set_cs(struct spi_device *spi, bool enable)
+{
+	struct spi_lp8841_rtc *data = spi_master_get_devdata(spi->master);
+
+	data->state = 0;
+	writeb(data->state, data->iomem);
+	if (enable) {
+		usleep_range(4, 5);
+		data->state |= SPI_LP8841_RTC_CE;
+		writeb(data->state, data->iomem);
+		usleep_range(4, 5);
+	}
+}
+
+static int
+spi_lp8841_rtc_setup(struct spi_device *spi)
+{
+	if ((spi->mode & SPI_CS_HIGH) == 0) {
+		dev_err(&spi->dev, "unsupported active low chip select\n");
+		return -EINVAL;
+	}
+
+	if ((spi->mode & SPI_LSB_FIRST) == 0) {
+		dev_err(&spi->dev, "unsupported MSB first mode\n");
+		return -EINVAL;
+	}
+
+	if ((spi->mode & SPI_3WIRE) == 0) {
+		dev_err(&spi->dev, "unsupported wiring. 3 wires required\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id spi_lp8841_rtc_dt_ids[] = {
+	{ .compatible = "icpdas,lp8841-spi-rtc" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, spi_lp8841_rtc_dt_ids);
+#endif
+
+static int
+spi_lp8841_rtc_probe(struct platform_device *pdev)
+{
+	int				ret;
+	struct spi_master		*master;
+	struct spi_lp8841_rtc		*data;
+	void				*iomem;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*data));
+	if (!master)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, master);
+
+	master->flags = SPI_MASTER_HALF_DUPLEX;
+	master->mode_bits = SPI_CS_HIGH | SPI_3WIRE | SPI_LSB_FIRST;
+
+	master->bus_num = pdev->id;
+	master->num_chipselect = 1;
+	master->setup = spi_lp8841_rtc_setup;
+	master->set_cs = spi_lp8841_rtc_set_cs;
+	master->transfer_one = spi_lp8841_rtc_transfer_one;
+	master->bits_per_word_mask = SPI_BPW_MASK(8);
+#ifdef CONFIG_OF
+	master->dev.of_node = pdev->dev.of_node;
+#endif
+
+	data = spi_master_get_devdata(master);
+
+	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->iomem = devm_ioremap_resource(&pdev->dev, iomem);
+	ret = PTR_ERR_OR_ZERO(data->iomem);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to get IO address\n");
+		goto err_put_master;
+	}
+
+	/* register with the SPI framework */
+	ret = devm_spi_register_master(&pdev->dev, master);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot register spi master\n");
+		goto err_put_master;
+	}
+
+	return ret;
+
+
+err_put_master:
+	spi_master_put(master);
+
+	return ret;
+}
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+
+static struct platform_driver spi_lp8841_rtc_driver = {
+	.driver = {
+		.name	= DRIVER_NAME,
+		.of_match_table = of_match_ptr(spi_lp8841_rtc_dt_ids),
+	},
+	.probe		= spi_lp8841_rtc_probe,
+};
+module_platform_driver(spi_lp8841_rtc_driver);
+
+MODULE_DESCRIPTION("SPI master driver for ICP DAS LP-8841 RTC");
+MODULE_AUTHOR("Sergei Ianovich");
+MODULE_LICENSE("GPL");

drivers/spi/spi-pl022.c

@@ -346,13 +346,6 @@ struct vendor_data {
  * @clk: outgoing clock "SPICLK" for the SPI bus
  * @master: SPI framework hookup
  * @master_info: controller-specific data from machine setup
- * @kworker: thread struct for message pump
- * @kworker_task: pointer to task for message pump kworker thread
- * @pump_messages: work struct for scheduling work to the message pump
- * @queue_lock: spinlock to syncronise access to message queue
- * @queue: message queue
- * @busy: message pump is busy
- * @running: message pump is running
  * @pump_transfers: Tasklet used in Interrupt Transfer mode
  * @cur_msg: Pointer to current spi_message being processed
  * @cur_transfer: Pointer to current spi_transfer

drivers/spi/spi-pxa2xx-dma.c

@@ -254,8 +254,8 @@ irqreturn_t pxa2xx_spi_dma_transfer(struct driver_data *drv_data)
 	if (status & SSSR_ROR) {
 		dev_err(&drv_data->pdev->dev, "FIFO overrun\n");
 
-		dmaengine_terminate_all(drv_data->rx_chan);
-		dmaengine_terminate_all(drv_data->tx_chan);
+		dmaengine_terminate_async(drv_data->rx_chan);
+		dmaengine_terminate_async(drv_data->tx_chan);
 
 		pxa2xx_spi_dma_transfer_complete(drv_data, true);
 		return IRQ_HANDLED;
@@ -331,13 +331,13 @@ int pxa2xx_spi_dma_setup(struct driver_data *drv_data)
 void pxa2xx_spi_dma_release(struct driver_data *drv_data)
 {
 	if (drv_data->rx_chan) {
-		dmaengine_terminate_all(drv_data->rx_chan);
+		dmaengine_terminate_sync(drv_data->rx_chan);
 		dma_release_channel(drv_data->rx_chan);
 		sg_free_table(&drv_data->rx_sgt);
 		drv_data->rx_chan = NULL;
 	}
 	if (drv_data->tx_chan) {
-		dmaengine_terminate_all(drv_data->tx_chan);
+		dmaengine_terminate_sync(drv_data->tx_chan);
 		dma_release_channel(drv_data->tx_chan);
 		sg_free_table(&drv_data->tx_sgt);
 		drv_data->tx_chan = NULL;

drivers/spi/spi-pxa2xx-pci.c

@@ -19,6 +19,7 @@ enum {
 	PORT_BSW1,
 	PORT_BSW2,
 	PORT_QUARK_X1000,
+	PORT_LPT,
 };
 
 struct pxa_spi_info {
@@ -42,6 +43,9 @@ static struct dw_dma_slave bsw1_rx_param = { .src_id = 7 };
 static struct dw_dma_slave bsw2_tx_param = { .dst_id = 8 };
 static struct dw_dma_slave bsw2_rx_param = { .src_id = 9 };
 
+static struct dw_dma_slave lpt_tx_param = { .dst_id = 0 };
+static struct dw_dma_slave lpt_rx_param = { .src_id = 1 };
+
 static bool lpss_dma_filter(struct dma_chan *chan, void *param)
 {
 	struct dw_dma_slave *dws = param;
@@ -98,6 +102,14 @@ static struct pxa_spi_info spi_info_configs[] = {
 		.num_chipselect = 1,
 		.max_clk_rate = 50000000,
 	},
+	[PORT_LPT] = {
+		.type = LPSS_LPT_SSP,
+		.port_id = 0,
+		.num_chipselect = 1,
+		.max_clk_rate = 50000000,
+		.tx_param = &lpt_tx_param,
+		.rx_param = &lpt_rx_param,
+	},
 };
 
 static int pxa2xx_spi_pci_probe(struct pci_dev *dev,
@@ -202,6 +214,7 @@ static const struct pci_device_id pxa2xx_spi_pci_devices[] = {
 	{ PCI_VDEVICE(INTEL, 0x228e), PORT_BSW0 },
 	{ PCI_VDEVICE(INTEL, 0x2290), PORT_BSW1 },
 	{ PCI_VDEVICE(INTEL, 0x22ac), PORT_BSW2 },
+	{ PCI_VDEVICE(INTEL, 0x9ce6), PORT_LPT },
 	{ },
 };
 MODULE_DEVICE_TABLE(pci, pxa2xx_spi_pci_devices);

drivers/spi/spi-pxa2xx.c

@@ -65,8 +65,6 @@ MODULE_ALIAS("platform:pxa2xx-spi");
 #define LPSS_GENERAL_REG_RXTO_HOLDOFF_DISABLE	BIT(24)
 #define LPSS_CS_CONTROL_SW_MODE			BIT(0)
 #define LPSS_CS_CONTROL_CS_HIGH			BIT(1)
-#define LPSS_CS_CONTROL_CS_SEL_SHIFT		8
-#define LPSS_CS_CONTROL_CS_SEL_MASK		(3 << LPSS_CS_CONTROL_CS_SEL_SHIFT)
 #define LPSS_CAPS_CS_EN_SHIFT			9
 #define LPSS_CAPS_CS_EN_MASK			(0xf << LPSS_CAPS_CS_EN_SHIFT)
 
@@ -82,6 +80,10 @@ struct lpss_config {
 	u32 rx_threshold;
 	u32 tx_threshold_lo;
 	u32 tx_threshold_hi;
+	/* Chip select control */
+	unsigned cs_sel_shift;
+	unsigned cs_sel_mask;
+	unsigned cs_num;
 };
 
 /* Keep these sorted with enum pxa_ssp_type */
@@ -106,6 +108,19 @@ static const struct lpss_config lpss_platforms[] = {
 		.tx_threshold_lo = 160,
 		.tx_threshold_hi = 224,
 	},
+	{	/* LPSS_BSW_SSP */
+		.offset = 0x400,
+		.reg_general = 0x08,
+		.reg_ssp = 0x0c,
+		.reg_cs_ctrl = 0x18,
+		.reg_capabilities = -1,
+		.rx_threshold = 64,
+		.tx_threshold_lo = 160,
+		.tx_threshold_hi = 224,
+		.cs_sel_shift = 2,
+		.cs_sel_mask = 1 << 2,
+		.cs_num = 2,
+	},
 	{	/* LPSS_SPT_SSP */
 		.offset = 0x200,
 		.reg_general = -1,
@@ -125,6 +140,8 @@ static const struct lpss_config lpss_platforms[] = {
 		.rx_threshold = 1,
 		.tx_threshold_lo = 16,
 		.tx_threshold_hi = 48,
+		.cs_sel_shift = 8,
+		.cs_sel_mask = 3 << 8,
 	},
 };
 
@@ -139,6 +156,7 @@ static bool is_lpss_ssp(const struct driver_data *drv_data)
 	switch (drv_data->ssp_type) {
 	case LPSS_LPT_SSP:
 	case LPSS_BYT_SSP:
+	case LPSS_BSW_SSP:
 	case LPSS_SPT_SSP:
 	case LPSS_BXT_SSP:
 		return true;
@@ -288,37 +306,50 @@ static void lpss_ssp_setup(struct driver_data *drv_data)
 	}
 }
 
+static void lpss_ssp_select_cs(struct driver_data *drv_data,
+			       const struct lpss_config *config)
+{
+	u32 value, cs;
+
+	if (!config->cs_sel_mask)
+		return;
+
+	value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
+
+	cs = drv_data->cur_msg->spi->chip_select;
+	cs <<= config->cs_sel_shift;
+	if (cs != (value & config->cs_sel_mask)) {
+		/*
+		 * When switching another chip select output active the
+		 * output must be selected first and wait 2 ssp_clk cycles
+		 * before changing state to active. Otherwise a short
+		 * glitch will occur on the previous chip select since
+		 * output select is latched but state control is not.
+		 */
+		value &= ~config->cs_sel_mask;
+		value |= cs;
+		__lpss_ssp_write_priv(drv_data,
+				      config->reg_cs_ctrl, value);
+		ndelay(1000000000 /
+		       (drv_data->master->max_speed_hz / 2));
+	}
+}
+
 static void lpss_ssp_cs_control(struct driver_data *drv_data, bool enable)
 {
 	const struct lpss_config *config;
-	u32 value, cs;
+	u32 value;
 
 	config = lpss_get_config(drv_data);
 
+	if (enable)
+		lpss_ssp_select_cs(drv_data, config);
+
 	value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
-	if (enable) {
-		cs = drv_data->cur_msg->spi->chip_select;
-		cs <<= LPSS_CS_CONTROL_CS_SEL_SHIFT;
-		if (cs != (value & LPSS_CS_CONTROL_CS_SEL_MASK)) {
-			/*
-			 * When switching another chip select output active
-			 * the output must be selected first and wait 2 ssp_clk
-			 * cycles before changing state to active. Otherwise
-			 * a short glitch will occur on the previous chip
-			 * select since output select is latched but state
-			 * control is not.
-			 */
-			value &= ~LPSS_CS_CONTROL_CS_SEL_MASK;
-			value |= cs;
-			__lpss_ssp_write_priv(drv_data,
-					      config->reg_cs_ctrl, value);
-			ndelay(1000000000 /
-			       (drv_data->master->max_speed_hz / 2));
-		}
+	if (enable)
 		value &= ~LPSS_CS_CONTROL_CS_HIGH;
-	} else {
+	else
 		value |= LPSS_CS_CONTROL_CS_HIGH;
-	}
 	__lpss_ssp_write_priv(drv_data, config->reg_cs_ctrl, value);
 }
 
@@ -496,6 +527,7 @@ static void giveback(struct driver_data *drv_data)
 {
 	struct spi_transfer* last_transfer;
 	struct spi_message *msg;
+	unsigned long timeout;
 
 	msg = drv_data->cur_msg;
 	drv_data->cur_msg = NULL;
@@ -508,6 +540,12 @@ static void giveback(struct driver_data *drv_data)
 	if (last_transfer->delay_usecs)
 		udelay(last_transfer->delay_usecs);
 
+	/* Wait until SSP becomes idle before deasserting the CS */
+	timeout = jiffies + msecs_to_jiffies(10);
+	while (pxa2xx_spi_read(drv_data, SSSR) & SSSR_BSY &&
+	       !time_after(jiffies, timeout))
+		cpu_relax();
+
 	/* Drop chip select UNLESS cs_change is true or we are returning
 	 * a message with an error, or next message is for another chip
 	 */
@@ -572,7 +610,7 @@ static void int_error_stop(struct driver_data *drv_data, const char* msg)
 
 static void int_transfer_complete(struct driver_data *drv_data)
 {
-	/* Stop SSP */
+	/* Clear and disable interrupts */
 	write_SSSR_CS(drv_data, drv_data->clear_sr);
 	reset_sccr1(drv_data);
 	if (!pxa25x_ssp_comp(drv_data))
@@ -957,8 +995,6 @@ static void pump_transfers(unsigned long data)
 	drv_data->tx_end = drv_data->tx + transfer->len;
 	drv_data->rx = transfer->rx_buf;
 	drv_data->rx_end = drv_data->rx + transfer->len;
-	drv_data->rx_dma = transfer->rx_dma;
-	drv_data->tx_dma = transfer->tx_dma;
 	drv_data->len = transfer->len;
 	drv_data->write = drv_data->tx ? chip->write : null_writer;
 	drv_data->read = drv_data->rx ? chip->read : null_reader;
@@ -1001,19 +1037,6 @@ static void pump_transfers(unsigned long data)
 					     "pump_transfers: DMA burst size reduced to match bits_per_word\n");
 	}
 
-	/* NOTE:  PXA25x_SSP _could_ use external clocking ... */
-	cr0 = pxa2xx_configure_sscr0(drv_data, clk_div, bits);
-	if (!pxa25x_ssp_comp(drv_data))
-		dev_dbg(&message->spi->dev, "%u Hz actual, %s\n",
-			drv_data->master->max_speed_hz
-				/ (1 + ((cr0 & SSCR0_SCR(0xfff)) >> 8)),
-			chip->enable_dma ? "DMA" : "PIO");
-	else
-		dev_dbg(&message->spi->dev, "%u Hz actual, %s\n",
-			drv_data->master->max_speed_hz / 2
-				/ (1 + ((cr0 & SSCR0_SCR(0x0ff)) >> 8)),
-			chip->enable_dma ? "DMA" : "PIO");
-
 	message->state = RUNNING_STATE;
 
 	drv_data->dma_mapped = 0;
@@ -1040,6 +1063,19 @@ static void pump_transfers(unsigned long data)
 		write_SSSR_CS(drv_data, drv_data->clear_sr);
 	}
 
+	/* NOTE:  PXA25x_SSP _could_ use external clocking ... */
+	cr0 = pxa2xx_configure_sscr0(drv_data, clk_div, bits);
+	if (!pxa25x_ssp_comp(drv_data))
+		dev_dbg(&message->spi->dev, "%u Hz actual, %s\n",
+			drv_data->master->max_speed_hz
+				/ (1 + ((cr0 & SSCR0_SCR(0xfff)) >> 8)),
+			drv_data->dma_mapped ? "DMA" : "PIO");
+	else
+		dev_dbg(&message->spi->dev, "%u Hz actual, %s\n",
+			drv_data->master->max_speed_hz / 2
+				/ (1 + ((cr0 & SSCR0_SCR(0x0ff)) >> 8)),
+			drv_data->dma_mapped ? "DMA" : "PIO");
+
 	if (is_lpss_ssp(drv_data)) {
 		if ((pxa2xx_spi_read(drv_data, SSIRF) & 0xff)
 		    != chip->lpss_rx_threshold)
@@ -1166,6 +1202,7 @@ static int setup(struct spi_device *spi)
 		break;
 	case LPSS_LPT_SSP:
 	case LPSS_BYT_SSP:
+	case LPSS_BSW_SSP:
 	case LPSS_SPT_SSP:
 	case LPSS_BXT_SSP:
 		config = lpss_get_config(drv_data);
@@ -1313,7 +1350,7 @@ static const struct acpi_device_id pxa2xx_spi_acpi_match[] = {
 	{ "INT3430", LPSS_LPT_SSP },
 	{ "INT3431", LPSS_LPT_SSP },
 	{ "80860F0E", LPSS_BYT_SSP },
-	{ "8086228E", LPSS_BYT_SSP },
+	{ "8086228E", LPSS_BSW_SSP },
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, pxa2xx_spi_acpi_match);
@@ -1347,10 +1384,14 @@ static const struct pci_device_id pxa2xx_spi_pci_compound_match[] = {
 	/* SPT-H */
 	{ PCI_VDEVICE(INTEL, 0xa129), LPSS_SPT_SSP },
 	{ PCI_VDEVICE(INTEL, 0xa12a), LPSS_SPT_SSP },
-	/* BXT */
+	/* BXT A-Step */
 	{ PCI_VDEVICE(INTEL, 0x0ac2), LPSS_BXT_SSP },
 	{ PCI_VDEVICE(INTEL, 0x0ac4), LPSS_BXT_SSP },
 	{ PCI_VDEVICE(INTEL, 0x0ac6), LPSS_BXT_SSP },
+	/* BXT B-Step */
+	{ PCI_VDEVICE(INTEL, 0x1ac2), LPSS_BXT_SSP },
+	{ PCI_VDEVICE(INTEL, 0x1ac4), LPSS_BXT_SSP },
+	{ PCI_VDEVICE(INTEL, 0x1ac6), LPSS_BXT_SSP },
 	/* APL */
 	{ PCI_VDEVICE(INTEL, 0x5ac2), LPSS_BXT_SSP },
 	{ PCI_VDEVICE(INTEL, 0x5ac4), LPSS_BXT_SSP },
@@ -1438,6 +1479,29 @@ pxa2xx_spi_init_pdata(struct platform_device *pdev)
 }
 #endif
 
+static int pxa2xx_spi_fw_translate_cs(struct spi_master *master, unsigned cs)
+{
+	struct driver_data *drv_data = spi_master_get_devdata(master);
+
+	if (has_acpi_companion(&drv_data->pdev->dev)) {
+		switch (drv_data->ssp_type) {
+		/*
+		 * For Atoms the ACPI DeviceSelection used by the Windows
+		 * driver starts from 1 instead of 0 so translate it here
+		 * to match what Linux expects.
+		 */
+		case LPSS_BYT_SSP:
+		case LPSS_BSW_SSP:
+			return cs - 1;
+
+		default:
+			break;
+		}
+	}
+
+	return cs;
+}
+
 static int pxa2xx_spi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1490,6 +1554,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 	master->setup = setup;
 	master->transfer_one_message = pxa2xx_spi_transfer_one_message;
 	master->unprepare_transfer_hardware = pxa2xx_spi_unprepare_transfer;
+	master->fw_translate_cs = pxa2xx_spi_fw_translate_cs;
 	master->auto_runtime_pm = true;
 
 	drv_data->ssp_type = ssp->type;
@@ -1576,6 +1641,8 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 			tmp &= LPSS_CAPS_CS_EN_MASK;
 			tmp >>= LPSS_CAPS_CS_EN_SHIFT;
 			platform_info->num_chipselect = ffz(tmp);
+		} else if (config->cs_num) {
+			platform_info->num_chipselect = config->cs_num;
 		}
 	}
 	master->num_chipselect = platform_info->num_chipselect;

drivers/spi/spi-pxa2xx.h

@@ -69,8 +69,6 @@ struct driver_data {
 	void *rx;
 	void *rx_end;
 	int dma_mapped;
-	dma_addr_t rx_dma;
-	dma_addr_t tx_dma;
 	size_t rx_map_len;
 	size_t tx_map_len;
 	u8 n_bytes;
@@ -147,20 +145,9 @@ static inline void write_SSSR_CS(struct driver_data *drv_data, u32 val)
 extern int pxa2xx_spi_flush(struct driver_data *drv_data);
 extern void *pxa2xx_spi_next_transfer(struct driver_data *drv_data);
 
-/*
- * Select the right DMA implementation.
- */
-#if defined(CONFIG_SPI_PXA2XX_DMA)
-#define SPI_PXA2XX_USE_DMA	1
 #define MAX_DMA_LEN		SZ_64K
 #define DEFAULT_DMA_CR1		(SSCR1_TSRE | SSCR1_RSRE | SSCR1_TRAIL)
-#else
-#undef SPI_PXA2XX_USE_DMA
-#define MAX_DMA_LEN		0
-#define DEFAULT_DMA_CR1		0
-#endif
 
-#ifdef SPI_PXA2XX_USE_DMA
 extern bool pxa2xx_spi_dma_is_possible(size_t len);
 extern int pxa2xx_spi_map_dma_buffers(struct driver_data *drv_data);
 extern irqreturn_t pxa2xx_spi_dma_transfer(struct driver_data *drv_data);
@@ -173,29 +160,5 @@ extern int pxa2xx_spi_set_dma_burst_and_threshold(struct chip_data *chip,
 						  u8 bits_per_word,
 						  u32 *burst_code,
 						  u32 *threshold);
-#else
-static inline bool pxa2xx_spi_dma_is_possible(size_t len) { return false; }
-static inline int pxa2xx_spi_map_dma_buffers(struct driver_data *drv_data)
-{
-	return 0;
-}
-#define pxa2xx_spi_dma_transfer NULL
-static inline void pxa2xx_spi_dma_prepare(struct driver_data *drv_data,
-					  u32 dma_burst) {}
-static inline void pxa2xx_spi_dma_start(struct driver_data *drv_data) {}
-static inline int pxa2xx_spi_dma_setup(struct driver_data *drv_data)
-{
-	return 0;
-}
-static inline void pxa2xx_spi_dma_release(struct driver_data *drv_data) {}
-static inline int pxa2xx_spi_set_dma_burst_and_threshold(struct chip_data *chip,
-							 struct spi_device *spi,
-							 u8 bits_per_word,
-							 u32 *burst_code,
-							 u32 *threshold)
-{
-	return -ENODEV;
-}
-#endif
 
 #endif /* SPI_PXA2XX_H */

drivers/spi/spi-rockchip.c

@@ -13,20 +13,14 @@
  *
  */
 
-#include <linux/init.h>
-#include <linux/module.h>
 #include <linux/clk.h>
-#include <linux/err.h>
-#include <linux/delay.h>
-#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
-#include <linux/slab.h>
 #include <linux/spi/spi.h>
-#include <linux/scatterlist.h>
-#include <linux/of.h>
 #include <linux/pm_runtime.h>
-#include <linux/io.h>
-#include <linux/dmaengine.h>
+#include <linux/scatterlist.h>
 
 #define DRIVER_NAME "rockchip-spi"
 
@@ -179,7 +173,7 @@ struct rockchip_spi {
 	u8 tmode;
 	u8 bpw;
 	u8 n_bytes;
-	u8 rsd_nsecs;
+	u32 rsd_nsecs;
 	unsigned len;
 	u32 speed;
 
@@ -192,8 +186,6 @@ struct rockchip_spi {
 	/* protect state */
 	spinlock_t lock;
 
-	struct completion xfer_completion;
-
 	u32 use_dma;
 	struct sg_table tx_sg;
 	struct sg_table rx_sg;
@@ -265,7 +257,10 @@ static inline u32 rx_max(struct rockchip_spi *rs)
 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
 {
 	u32 ser;
-	struct rockchip_spi *rs = spi_master_get_devdata(spi->master);
+	struct spi_master *master = spi->master;
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	pm_runtime_get_sync(rs->dev);
 
 	ser = readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & SER_MASK;
 
@@ -290,6 +285,8 @@ static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
 		ser &= ~(1 << spi->chip_select);
 
 	writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER);
+
+	pm_runtime_put_sync(rs->dev);
 }
 
 static int rockchip_spi_prepare_message(struct spi_master *master,
@@ -319,12 +316,12 @@ static void rockchip_spi_handle_err(struct spi_master *master,
 	 */
 	if (rs->use_dma) {
 		if (rs->state & RXBUSY) {
-			dmaengine_terminate_all(rs->dma_rx.ch);
+			dmaengine_terminate_async(rs->dma_rx.ch);
 			flush_fifo(rs);
 		}
 
 		if (rs->state & TXBUSY)
-			dmaengine_terminate_all(rs->dma_tx.ch);
+			dmaengine_terminate_async(rs->dma_tx.ch);
 	}
 
 	spin_unlock_irqrestore(&rs->lock, flags);
@@ -433,7 +430,7 @@ static void rockchip_spi_dma_txcb(void *data)
 	spin_unlock_irqrestore(&rs->lock, flags);
 }
 
-static void rockchip_spi_prepare_dma(struct rockchip_spi *rs)
+static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
 {
 	unsigned long flags;
 	struct dma_slave_config rxconf, txconf;
@@ -456,6 +453,8 @@ static void rockchip_spi_prepare_dma(struct rockchip_spi *rs)
 				rs->dma_rx.ch,
 				rs->rx_sg.sgl, rs->rx_sg.nents,
 				rs->dma_rx.direction, DMA_PREP_INTERRUPT);
+		if (!rxdesc)
+			return -EINVAL;
 
 		rxdesc->callback = rockchip_spi_dma_rxcb;
 		rxdesc->callback_param = rs;
@@ -473,6 +472,11 @@ static void rockchip_spi_prepare_dma(struct rockchip_spi *rs)
 				rs->dma_tx.ch,
 				rs->tx_sg.sgl, rs->tx_sg.nents,
 				rs->dma_tx.direction, DMA_PREP_INTERRUPT);
+		if (!txdesc) {
+			if (rxdesc)
+				dmaengine_terminate_sync(rs->dma_rx.ch);
+			return -EINVAL;
+		}
 
 		txdesc->callback = rockchip_spi_dma_txcb;
 		txdesc->callback_param = rs;
@@ -494,6 +498,8 @@ static void rockchip_spi_prepare_dma(struct rockchip_spi *rs)
 		dmaengine_submit(txdesc);
 		dma_async_issue_pending(rs->dma_tx.ch);
 	}
+
+	return 0;
 }
 
 static void rockchip_spi_config(struct rockchip_spi *rs)
@@ -503,7 +509,8 @@ static void rockchip_spi_config(struct rockchip_spi *rs)
 	int rsd = 0;
 
 	u32 cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
-		| (CR0_SSD_ONE << CR0_SSD_OFFSET);
+		| (CR0_SSD_ONE << CR0_SSD_OFFSET)
+		| (CR0_EM_BIG << CR0_EM_OFFSET);
 
 	cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
 	cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
@@ -606,12 +613,12 @@ static int rockchip_spi_transfer_one(
 	if (rs->use_dma) {
 		if (rs->tmode == CR0_XFM_RO) {
 			/* rx: dma must be prepared first */
-			rockchip_spi_prepare_dma(rs);
+			ret = rockchip_spi_prepare_dma(rs);
 			spi_enable_chip(rs, 1);
 		} else {
 			/* tx or tr: spi must be enabled first */
 			spi_enable_chip(rs, 1);
-			rockchip_spi_prepare_dma(rs);
+			ret = rockchip_spi_prepare_dma(rs);
 		}
 	} else {
 		spi_enable_chip(rs, 1);
@@ -717,8 +724,14 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 	master->handle_err = rockchip_spi_handle_err;
 
 	rs->dma_tx.ch = dma_request_slave_channel(rs->dev, "tx");
-	if (!rs->dma_tx.ch)
+	if (IS_ERR_OR_NULL(rs->dma_tx.ch)) {
+		/* Check tx to see if we need defer probing driver */
+		if (PTR_ERR(rs->dma_tx.ch) == -EPROBE_DEFER) {
+			ret = -EPROBE_DEFER;
+			goto err_get_fifo_len;
+		}
 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
+	}
 
 	rs->dma_rx.ch = dma_request_slave_channel(rs->dev, "rx");
 	if (!rs->dma_rx.ch) {
@@ -871,6 +884,7 @@ static const struct of_device_id rockchip_spi_dt_match[] = {
 	{ .compatible = "rockchip,rk3066-spi", },
 	{ .compatible = "rockchip,rk3188-spi", },
 	{ .compatible = "rockchip,rk3288-spi", },
+	{ .compatible = "rockchip,rk3399-spi", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);

drivers/spi/spi-ti-qspi.c

@@ -31,6 +31,8 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/pinctrl/consumer.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 
 #include <linux/spi/spi.h>
 
@@ -44,8 +46,9 @@ struct ti_qspi {
 
 	struct spi_master	*master;
 	void __iomem            *base;
-	void __iomem            *ctrl_base;
 	void __iomem            *mmap_base;
+	struct regmap		*ctrl_base;
+	unsigned int		ctrl_reg;
 	struct clk		*fclk;
 	struct device           *dev;
 
@@ -55,7 +58,7 @@ struct ti_qspi {
 	u32 cmd;
 	u32 dc;
 
-	bool ctrl_mod;
+	bool mmap_enabled;
 };
 
 #define QSPI_PID			(0x0)
@@ -65,11 +68,8 @@ struct ti_qspi {
 #define QSPI_SPI_CMD_REG		(0x48)
 #define QSPI_SPI_STATUS_REG		(0x4c)
 #define QSPI_SPI_DATA_REG		(0x50)
-#define QSPI_SPI_SETUP0_REG		(0x54)
+#define QSPI_SPI_SETUP_REG(n)		((0x54 + 4 * n))
 #define QSPI_SPI_SWITCH_REG		(0x64)
-#define QSPI_SPI_SETUP1_REG		(0x58)
-#define QSPI_SPI_SETUP2_REG		(0x5c)
-#define QSPI_SPI_SETUP3_REG		(0x60)
 #define QSPI_SPI_DATA_REG_1		(0x68)
 #define QSPI_SPI_DATA_REG_2		(0x6c)
 #define QSPI_SPI_DATA_REG_3		(0x70)
@@ -109,6 +109,17 @@ struct ti_qspi {
 
 #define QSPI_AUTOSUSPEND_TIMEOUT         2000
 
+#define MEM_CS_EN(n)			((n + 1) << 8)
+#define MEM_CS_MASK			(7 << 8)
+
+#define MM_SWITCH			0x1
+
+#define QSPI_SETUP_RD_NORMAL		(0x0 << 12)
+#define QSPI_SETUP_RD_DUAL		(0x1 << 12)
+#define QSPI_SETUP_RD_QUAD		(0x3 << 12)
+#define QSPI_SETUP_ADDR_SHIFT		8
+#define QSPI_SETUP_DUMMY_SHIFT		10
+
 static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
 		unsigned long reg)
 {
@@ -366,6 +377,72 @@ static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 	return 0;
 }
 
+static void ti_qspi_enable_memory_map(struct spi_device *spi)
+{
+	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
+
+	ti_qspi_write(qspi, MM_SWITCH, QSPI_SPI_SWITCH_REG);
+	if (qspi->ctrl_base) {
+		regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
+				   MEM_CS_EN(spi->chip_select),
+				   MEM_CS_MASK);
+	}
+	qspi->mmap_enabled = true;
+}
+
+static void ti_qspi_disable_memory_map(struct spi_device *spi)
+{
+	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
+
+	ti_qspi_write(qspi, 0, QSPI_SPI_SWITCH_REG);
+	if (qspi->ctrl_base)
+		regmap_update_bits(qspi->ctrl_base, qspi->ctrl_reg,
+				   0, MEM_CS_MASK);
+	qspi->mmap_enabled = false;
+}
+
+static void ti_qspi_setup_mmap_read(struct spi_device *spi,
+				    struct spi_flash_read_message *msg)
+{
+	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
+	u32 memval = msg->read_opcode;
+
+	switch (msg->data_nbits) {
+	case SPI_NBITS_QUAD:
+		memval |= QSPI_SETUP_RD_QUAD;
+		break;
+	case SPI_NBITS_DUAL:
+		memval |= QSPI_SETUP_RD_DUAL;
+		break;
+	default:
+		memval |= QSPI_SETUP_RD_NORMAL;
+		break;
+	}
+	memval |= ((msg->addr_width - 1) << QSPI_SETUP_ADDR_SHIFT |
+		   msg->dummy_bytes << QSPI_SETUP_DUMMY_SHIFT);
+	ti_qspi_write(qspi, memval,
+		      QSPI_SPI_SETUP_REG(spi->chip_select));
+}
+
+static int ti_qspi_spi_flash_read(struct  spi_device *spi,
+				  struct spi_flash_read_message *msg)
+{
+	struct ti_qspi *qspi = spi_master_get_devdata(spi->master);
+	int ret = 0;
+
+	mutex_lock(&qspi->list_lock);
+
+	if (!qspi->mmap_enabled)
+		ti_qspi_enable_memory_map(spi);
+	ti_qspi_setup_mmap_read(spi, msg);
+	memcpy_fromio(msg->buf, qspi->mmap_base + msg->from, msg->len);
+	msg->retlen = msg->len;
+
+	mutex_unlock(&qspi->list_lock);
+
+	return ret;
+}
+
 static int ti_qspi_start_transfer_one(struct spi_master *master,
 		struct spi_message *m)
 {
@@ -398,6 +475,9 @@ static int ti_qspi_start_transfer_one(struct spi_master *master,
 
 	mutex_lock(&qspi->list_lock);
 
+	if (qspi->mmap_enabled)
+		ti_qspi_disable_memory_map(spi);
+
 	list_for_each_entry(t, &m->transfers, transfer_list) {
 		qspi->cmd |= QSPI_WLEN(t->bits_per_word);
 
@@ -441,7 +521,7 @@ static int ti_qspi_probe(struct platform_device *pdev)
 {
 	struct  ti_qspi *qspi;
 	struct spi_master *master;
-	struct resource         *r, *res_ctrl, *res_mmap;
+	struct resource         *r, *res_mmap;
 	struct device_node *np = pdev->dev.of_node;
 	u32 max_freq;
 	int ret = 0, num_cs, irq;
@@ -487,16 +567,6 @@ static int ti_qspi_probe(struct platform_device *pdev)
 		}
 	}
 
-	res_ctrl = platform_get_resource_byname(pdev,
-			IORESOURCE_MEM, "qspi_ctrlmod");
-	if (res_ctrl == NULL) {
-		res_ctrl = platform_get_resource(pdev, IORESOURCE_MEM, 2);
-		if (res_ctrl == NULL) {
-			dev_dbg(&pdev->dev,
-				"control module resources not required\n");
-		}
-	}
-
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		dev_err(&pdev->dev, "no irq resource?\n");
@@ -511,20 +581,31 @@ static int ti_qspi_probe(struct platform_device *pdev)
 		goto free_master;
 	}
 
-	if (res_ctrl) {
-		qspi->ctrl_mod = true;
-		qspi->ctrl_base = devm_ioremap_resource(&pdev->dev, res_ctrl);
-		if (IS_ERR(qspi->ctrl_base)) {
-			ret = PTR_ERR(qspi->ctrl_base);
-			goto free_master;
-		}
-	}
-
 	if (res_mmap) {
-		qspi->mmap_base = devm_ioremap_resource(&pdev->dev, res_mmap);
+		qspi->mmap_base = devm_ioremap_resource(&pdev->dev,
+							res_mmap);
+		master->spi_flash_read = ti_qspi_spi_flash_read;
 		if (IS_ERR(qspi->mmap_base)) {
-			ret = PTR_ERR(qspi->mmap_base);
-			goto free_master;
+			dev_err(&pdev->dev,
+				"falling back to PIO mode\n");
+			master->spi_flash_read = NULL;
+		}
+	}
+	qspi->mmap_enabled = false;
+
+	if (of_property_read_bool(np, "syscon-chipselects")) {
+		qspi->ctrl_base =
+		syscon_regmap_lookup_by_phandle(np,
+						"syscon-chipselects");
+		if (IS_ERR(qspi->ctrl_base))
+			return PTR_ERR(qspi->ctrl_base);
+		ret = of_property_read_u32_index(np,
+						 "syscon-chipselects",
+						 1, &qspi->ctrl_reg);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"couldn't get ctrl_mod reg index\n");
+			return ret;
 		}
 	}
 

drivers/spi/spi.c

@@ -144,6 +144,8 @@ SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
 SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
 SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
 
+SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
+
 static struct attribute *spi_dev_attrs[] = {
 	&dev_attr_modalias.attr,
 	NULL,
@@ -181,6 +183,7 @@ static struct attribute *spi_device_statistics_attrs[] = {
 	&dev_attr_spi_device_transfer_bytes_histo14.attr,
 	&dev_attr_spi_device_transfer_bytes_histo15.attr,
 	&dev_attr_spi_device_transfer_bytes_histo16.attr,
+	&dev_attr_spi_device_transfers_split_maxsize.attr,
 	NULL,
 };
 
@@ -223,6 +226,7 @@ static struct attribute *spi_master_statistics_attrs[] = {
 	&dev_attr_spi_master_transfer_bytes_histo14.attr,
 	&dev_attr_spi_master_transfer_bytes_histo15.attr,
 	&dev_attr_spi_master_transfer_bytes_histo16.attr,
+	&dev_attr_spi_master_transfers_split_maxsize.attr,
 	NULL,
 };
 
@@ -702,6 +706,7 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
 		       enum dma_data_direction dir)
 {
 	const bool vmalloced_buf = is_vmalloc_addr(buf);
+	unsigned int max_seg_size = dma_get_max_seg_size(dev);
 	int desc_len;
 	int sgs;
 	struct page *vm_page;
@@ -710,10 +715,10 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
 	int i, ret;
 
 	if (vmalloced_buf) {
-		desc_len = PAGE_SIZE;
+		desc_len = min_t(int, max_seg_size, PAGE_SIZE);
 		sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
 	} else {
-		desc_len = master->max_dma_len;
+		desc_len = min_t(int, max_seg_size, master->max_dma_len);
 		sgs = DIV_ROUND_UP(len, desc_len);
 	}
 
@@ -739,7 +744,6 @@ static int spi_map_buf(struct spi_master *master, struct device *dev,
 			sg_set_buf(&sgt->sgl[i], sg_buf, min);
 		}
 
-
 		buf += min;
 		len -= min;
 	}
@@ -1024,6 +1028,8 @@ static int spi_transfer_one_message(struct spi_master *master,
 	if (msg->status && master->handle_err)
 		master->handle_err(master, msg);
 
+	spi_res_release(master, msg);
+
 	spi_finalize_current_message(master);
 
 	return ret;
@@ -1047,6 +1053,7 @@ EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
  * __spi_pump_messages - function which processes spi message queue
  * @master: master to process queue for
  * @in_kthread: true if we are in the context of the message pump thread
+ * @bus_locked: true if the bus mutex is held when calling this function
  *
  * This function checks if there is any spi message in the queue that
  * needs processing and if so call out to the driver to initialize hardware
@@ -1056,7 +1063,8 @@ EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
  * inside spi_sync(); the queue extraction handling at the top of the
  * function should deal with this safely.
  */
-static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
+static void __spi_pump_messages(struct spi_master *master, bool in_kthread,
+				bool bus_locked)
 {
 	unsigned long flags;
 	bool was_busy = false;
@@ -1152,6 +1160,9 @@ static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
 		}
 	}
 
+	if (!bus_locked)
+		mutex_lock(&master->bus_lock_mutex);
+
 	trace_spi_message_start(master->cur_msg);
 
 	if (master->prepare_message) {
@@ -1161,7 +1172,7 @@ static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
 				"failed to prepare message: %d\n", ret);
 			master->cur_msg->status = ret;
 			spi_finalize_current_message(master);
-			return;
+			goto out;
 		}
 		master->cur_msg_prepared = true;
 	}
@@ -1170,15 +1181,23 @@ static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
 	if (ret) {
 		master->cur_msg->status = ret;
 		spi_finalize_current_message(master);
-		return;
+		goto out;
 	}
 
 	ret = master->transfer_one_message(master, master->cur_msg);
 	if (ret) {
 		dev_err(&master->dev,
 			"failed to transfer one message from queue\n");
-		return;
+		goto out;
 	}
+
+out:
+	if (!bus_locked)
+		mutex_unlock(&master->bus_lock_mutex);
+
+	/* Prod the scheduler in case transfer_one() was busy waiting */
+	if (!ret)
+		cond_resched();
 }
 
 /**
@@ -1190,7 +1209,7 @@ static void spi_pump_messages(struct kthread_work *work)
 	struct spi_master *master =
 		container_of(work, struct spi_master, pump_messages);
 
-	__spi_pump_messages(master, true);
+	__spi_pump_messages(master, true, false);
 }
 
 static int spi_init_queue(struct spi_master *master)
@@ -1581,13 +1600,30 @@ static void of_register_spi_devices(struct spi_master *master) { }
 static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
 {
 	struct spi_device *spi = data;
+	struct spi_master *master = spi->master;
 
 	if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
 		struct acpi_resource_spi_serialbus *sb;
 
 		sb = &ares->data.spi_serial_bus;
 		if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
-			spi->chip_select = sb->device_selection;
+			/*
+			 * ACPI DeviceSelection numbering is handled by the
+			 * host controller driver in Windows and can vary
+			 * from driver to driver. In Linux we always expect
+			 * 0 .. max - 1 so we need to ask the driver to
+			 * translate between the two schemes.
+			 */
+			if (master->fw_translate_cs) {
+				int cs = master->fw_translate_cs(master,
+						sb->device_selection);
+				if (cs < 0)
+					return cs;
+				spi->chip_select = cs;
+			} else {
+				spi->chip_select = sb->device_selection;
+			}
+
 			spi->max_speed_hz = sb->connection_speed;
 
 			if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
@@ -2013,6 +2049,336 @@ struct spi_master *spi_busnum_to_master(u16 bus_num)
 }
 EXPORT_SYMBOL_GPL(spi_busnum_to_master);
 
+/*-------------------------------------------------------------------------*/
+
+/* Core methods for SPI resource management */
+
+/**
+ * spi_res_alloc - allocate a spi resource that is life-cycle managed
+ *                 during the processing of a spi_message while using
+ *                 spi_transfer_one
+ * @spi:     the spi device for which we allocate memory
+ * @release: the release code to execute for this resource
+ * @size:    size to alloc and return
+ * @gfp:     GFP allocation flags
+ *
+ * Return: the pointer to the allocated data
+ *
+ * This may get enhanced in the future to allocate from a memory pool
+ * of the @spi_device or @spi_master to avoid repeated allocations.
+ */
+void *spi_res_alloc(struct spi_device *spi,
+		    spi_res_release_t release,
+		    size_t size, gfp_t gfp)
+{
+	struct spi_res *sres;
+
+	sres = kzalloc(sizeof(*sres) + size, gfp);
+	if (!sres)
+		return NULL;
+
+	INIT_LIST_HEAD(&sres->entry);
+	sres->release = release;
+
+	return sres->data;
+}
+EXPORT_SYMBOL_GPL(spi_res_alloc);
+
+/**
+ * spi_res_free - free an spi resource
+ * @res: pointer to the custom data of a resource
+ *
+ */
+void spi_res_free(void *res)
+{
+	struct spi_res *sres = container_of(res, struct spi_res, data);
+
+	if (!res)
+		return;
+
+	WARN_ON(!list_empty(&sres->entry));
+	kfree(sres);
+}
+EXPORT_SYMBOL_GPL(spi_res_free);
+
+/**
+ * spi_res_add - add a spi_res to the spi_message
+ * @message: the spi message
+ * @res:     the spi_resource
+ */
+void spi_res_add(struct spi_message *message, void *res)
+{
+	struct spi_res *sres = container_of(res, struct spi_res, data);
+
+	WARN_ON(!list_empty(&sres->entry));
+	list_add_tail(&sres->entry, &message->resources);
+}
+EXPORT_SYMBOL_GPL(spi_res_add);
+
+/**
+ * spi_res_release - release all spi resources for this message
+ * @master:  the @spi_master
+ * @message: the @spi_message
+ */
+void spi_res_release(struct spi_master *master,
+		     struct spi_message *message)
+{
+	struct spi_res *res;
+
+	while (!list_empty(&message->resources)) {
+		res = list_last_entry(&message->resources,
+				      struct spi_res, entry);
+
+		if (res->release)
+			res->release(master, message, res->data);
+
+		list_del(&res->entry);
+
+		kfree(res);
+	}
+}
+EXPORT_SYMBOL_GPL(spi_res_release);
+
+/*-------------------------------------------------------------------------*/
+
+/* Core methods for spi_message alterations */
+
+static void __spi_replace_transfers_release(struct spi_master *master,
+					    struct spi_message *msg,
+					    void *res)
+{
+	struct spi_replaced_transfers *rxfer = res;
+	size_t i;
+
+	/* call extra callback if requested */
+	if (rxfer->release)
+		rxfer->release(master, msg, res);
+
+	/* insert replaced transfers back into the message */
+	list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
+
+	/* remove the formerly inserted entries */
+	for (i = 0; i < rxfer->inserted; i++)
+		list_del(&rxfer->inserted_transfers[i].transfer_list);
+}
+
+/**
+ * spi_replace_transfers - replace transfers with several transfers
+ *                         and register change with spi_message.resources
+ * @msg:           the spi_message we work upon
+ * @xfer_first:    the first spi_transfer we want to replace
+ * @remove:        number of transfers to remove
+ * @insert:        the number of transfers we want to insert instead
+ * @release:       extra release code necessary in some circumstances
+ * @extradatasize: extra data to allocate (with alignment guarantees
+ *                 of struct @spi_transfer)
+ * @gfp:           gfp flags
+ *
+ * Returns: pointer to @spi_replaced_transfers,
+ *          PTR_ERR(...) in case of errors.
+ */
+struct spi_replaced_transfers *spi_replace_transfers(
+	struct spi_message *msg,
+	struct spi_transfer *xfer_first,
+	size_t remove,
+	size_t insert,
+	spi_replaced_release_t release,
+	size_t extradatasize,
+	gfp_t gfp)
+{
+	struct spi_replaced_transfers *rxfer;
+	struct spi_transfer *xfer;
+	size_t i;
+
+	/* allocate the structure using spi_res */
+	rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
+			      insert * sizeof(struct spi_transfer)
+			      + sizeof(struct spi_replaced_transfers)
+			      + extradatasize,
+			      gfp);
+	if (!rxfer)
+		return ERR_PTR(-ENOMEM);
+
+	/* the release code to invoke before running the generic release */
+	rxfer->release = release;
+
+	/* assign extradata */
+	if (extradatasize)
+		rxfer->extradata =
+			&rxfer->inserted_transfers[insert];
+
+	/* init the replaced_transfers list */
+	INIT_LIST_HEAD(&rxfer->replaced_transfers);
+
+	/* assign the list_entry after which we should reinsert
+	 * the @replaced_transfers - it may be spi_message.messages!
+	 */
+	rxfer->replaced_after = xfer_first->transfer_list.prev;
+
+	/* remove the requested number of transfers */
+	for (i = 0; i < remove; i++) {
+		/* if the entry after replaced_after it is msg->transfers
+		 * then we have been requested to remove more transfers
+		 * than are in the list
+		 */
+		if (rxfer->replaced_after->next == &msg->transfers) {
+			dev_err(&msg->spi->dev,
+				"requested to remove more spi_transfers than are available\n");
+			/* insert replaced transfers back into the message */
+			list_splice(&rxfer->replaced_transfers,
+				    rxfer->replaced_after);
+
+			/* free the spi_replace_transfer structure */
+			spi_res_free(rxfer);
+
+			/* and return with an error */
+			return ERR_PTR(-EINVAL);
+		}
+
+		/* remove the entry after replaced_after from list of
+		 * transfers and add it to list of replaced_transfers
+		 */
+		list_move_tail(rxfer->replaced_after->next,
+			       &rxfer->replaced_transfers);
+	}
+
+	/* create copy of the given xfer with identical settings
+	 * based on the first transfer to get removed
+	 */
+	for (i = 0; i < insert; i++) {
+		/* we need to run in reverse order */
+		xfer = &rxfer->inserted_transfers[insert - 1 - i];
+
+		/* copy all spi_transfer data */
+		memcpy(xfer, xfer_first, sizeof(*xfer));
+
+		/* add to list */
+		list_add(&xfer->transfer_list, rxfer->replaced_after);
+
+		/* clear cs_change and delay_usecs for all but the last */
+		if (i) {
+			xfer->cs_change = false;
+			xfer->delay_usecs = 0;
+		}
+	}
+
+	/* set up inserted */
+	rxfer->inserted = insert;
+
+	/* and register it with spi_res/spi_message */
+	spi_res_add(msg, rxfer);
+
+	return rxfer;
+}
+EXPORT_SYMBOL_GPL(spi_replace_transfers);
+
+static int __spi_split_transfer_maxsize(struct spi_master *master,
+					struct spi_message *msg,
+					struct spi_transfer **xferp,
+					size_t maxsize,
+					gfp_t gfp)
+{
+	struct spi_transfer *xfer = *xferp, *xfers;
+	struct spi_replaced_transfers *srt;
+	size_t offset;
+	size_t count, i;
+
+	/* warn once about this fact that we are splitting a transfer */
+	dev_warn_once(&msg->spi->dev,
+		      "spi_transfer of length %i exceed max length of %zu - needed to split transfers\n",
+		      xfer->len, maxsize);
+
+	/* calculate how many we have to replace */
+	count = DIV_ROUND_UP(xfer->len, maxsize);
+
+	/* create replacement */
+	srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
+	if (IS_ERR(srt))
+		return PTR_ERR(srt);
+	xfers = srt->inserted_transfers;
+
+	/* now handle each of those newly inserted spi_transfers
+	 * note that the replacements spi_transfers all are preset
+	 * to the same values as *xferp, so tx_buf, rx_buf and len
+	 * are all identical (as well as most others)
+	 * so we just have to fix up len and the pointers.
+	 *
+	 * this also includes support for the depreciated
+	 * spi_message.is_dma_mapped interface
+	 */
+
+	/* the first transfer just needs the length modified, so we
+	 * run it outside the loop
+	 */
+	xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
+
+	/* all the others need rx_buf/tx_buf also set */
+	for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
+		/* update rx_buf, tx_buf and dma */
+		if (xfers[i].rx_buf)
+			xfers[i].rx_buf += offset;
+		if (xfers[i].rx_dma)
+			xfers[i].rx_dma += offset;
+		if (xfers[i].tx_buf)
+			xfers[i].tx_buf += offset;
+		if (xfers[i].tx_dma)
+			xfers[i].tx_dma += offset;
+
+		/* update length */
+		xfers[i].len = min(maxsize, xfers[i].len - offset);
+	}
+
+	/* we set up xferp to the last entry we have inserted,
+	 * so that we skip those already split transfers
+	 */
+	*xferp = &xfers[count - 1];
+
+	/* increment statistics counters */
+	SPI_STATISTICS_INCREMENT_FIELD(&master->statistics,
+				       transfers_split_maxsize);
+	SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
+				       transfers_split_maxsize);
+
+	return 0;
+}
+
+/**
+ * spi_split_tranfers_maxsize - split spi transfers into multiple transfers
+ *                              when an individual transfer exceeds a
+ *                              certain size
+ * @master:    the @spi_master for this transfer
+ * @msg:   the @spi_message to transform
+ * @maxsize:  the maximum when to apply this
+ * @gfp: GFP allocation flags
+ *
+ * Return: status of transformation
+ */
+int spi_split_transfers_maxsize(struct spi_master *master,
+				struct spi_message *msg,
+				size_t maxsize,
+				gfp_t gfp)
+{
+	struct spi_transfer *xfer;
+	int ret;
+
+	/* iterate over the transfer_list,
+	 * but note that xfer is advanced to the last transfer inserted
+	 * to avoid checking sizes again unnecessarily (also xfer does
+	 * potentiall belong to a different list by the time the
+	 * replacement has happened
+	 */
+	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+		if (xfer->len > maxsize) {
+			ret = __spi_split_transfer_maxsize(
+				master, msg, &xfer, maxsize, gfp);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
 
 /*-------------------------------------------------------------------------*/
 
@@ -2351,6 +2717,46 @@ int spi_async_locked(struct spi_device *spi, struct spi_message *message)
 EXPORT_SYMBOL_GPL(spi_async_locked);
 
 
+int spi_flash_read(struct spi_device *spi,
+		   struct spi_flash_read_message *msg)
+
+{
+	struct spi_master *master = spi->master;
+	int ret;
+
+	if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
+	     msg->addr_nbits == SPI_NBITS_DUAL) &&
+	    !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
+		return -EINVAL;
+	if ((msg->opcode_nbits == SPI_NBITS_QUAD ||
+	     msg->addr_nbits == SPI_NBITS_QUAD) &&
+	    !(spi->mode & SPI_TX_QUAD))
+		return -EINVAL;
+	if (msg->data_nbits == SPI_NBITS_DUAL &&
+	    !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
+		return -EINVAL;
+	if (msg->data_nbits == SPI_NBITS_QUAD &&
+	    !(spi->mode &  SPI_RX_QUAD))
+		return -EINVAL;
+
+	if (master->auto_runtime_pm) {
+		ret = pm_runtime_get_sync(master->dev.parent);
+		if (ret < 0) {
+			dev_err(&master->dev, "Failed to power device: %d\n",
+				ret);
+			return ret;
+		}
+	}
+	mutex_lock(&master->bus_lock_mutex);
+	ret = master->spi_flash_read(spi, msg);
+	mutex_unlock(&master->bus_lock_mutex);
+	if (master->auto_runtime_pm)
+		pm_runtime_put(master->dev.parent);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(spi_flash_read);
+
 /*-------------------------------------------------------------------------*/
 
 /* Utility methods for SPI master protocol drivers, layered on
@@ -2414,7 +2820,7 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message,
 						       spi_sync_immediate);
 			SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
 						       spi_sync_immediate);
-			__spi_pump_messages(master, false);
+			__spi_pump_messages(master, false, bus_locked);
 		}
 
 		wait_for_completion(&done);

include/linux/pxa2xx_ssp.h

@@ -197,6 +197,7 @@ enum pxa_ssp_type {
 	QUARK_X1000_SSP,
 	LPSS_LPT_SSP, /* Keep LPSS types sorted with lpss_platforms[] */
 	LPSS_BYT_SSP,
+	LPSS_BSW_SSP,
 	LPSS_SPT_SSP,
 	LPSS_BXT_SSP,
 };

include/linux/spi/spi.h

@@ -25,6 +25,7 @@
 struct dma_chan;
 struct spi_master;
 struct spi_transfer;
+struct spi_flash_read_message;
 
 /*
  * INTERFACES between SPI master-side drivers and SPI infrastructure.
@@ -53,6 +54,10 @@ extern struct bus_type spi_bus_type;
  *
  * @transfer_bytes_histo:
  *                 transfer bytes histogramm
+ *
+ * @transfers_split_maxsize:
+ *                 number of transfers that have been split because of
+ *                 maxsize limit
  */
 struct spi_statistics {
 	spinlock_t		lock; /* lock for the whole structure */
@@ -72,6 +77,8 @@ struct spi_statistics {
 
 #define SPI_STATISTICS_HISTO_SIZE 17
 	unsigned long transfer_bytes_histo[SPI_STATISTICS_HISTO_SIZE];
+
+	unsigned long transfers_split_maxsize;
 };
 
 void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
@@ -303,6 +310,8 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  * @min_speed_hz: Lowest supported transfer speed
  * @max_speed_hz: Highest supported transfer speed
  * @flags: other constraints relevant to this driver
+ * @max_transfer_size: function that returns the max transfer size for
+ *	a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
  * @bus_lock_spinlock: spinlock for SPI bus locking
  * @bus_lock_mutex: mutex for SPI bus locking
  * @bus_lock_flag: indicates that the SPI bus is locked for exclusive use
@@ -361,6 +370,8 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  * @handle_err: the subsystem calls the driver to handle an error that occurs
  *		in the generic implementation of transfer_one_message().
  * @unprepare_message: undo any work done by prepare_message().
+ * @spi_flash_read: to support spi-controller hardwares that provide
+ *                  accelerated interface to read from flash devices.
  * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS
  *	number. Any individual value may be -ENOENT for CS lines that
  *	are not GPIOs (driven by the SPI controller itself).
@@ -369,6 +380,9 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  * @dma_rx: DMA receive channel
  * @dummy_rx: dummy receive buffer for full-duplex devices
  * @dummy_tx: dummy transmit buffer for full-duplex devices
+ * @fw_translate_cs: If the boot firmware uses different numbering scheme
+ *	what Linux expects, this optional hook can be used to translate
+ *	between the two.
  *
  * Each SPI master controller can communicate with one or more @spi_device
  * children.  These make a small bus, sharing MOSI, MISO and SCK signals
@@ -513,6 +527,8 @@ struct spi_master {
 			       struct spi_message *message);
 	int (*unprepare_message)(struct spi_master *master,
 				 struct spi_message *message);
+	int (*spi_flash_read)(struct  spi_device *spi,
+			      struct spi_flash_read_message *msg);
 
 	/*
 	 * These hooks are for drivers that use a generic implementation
@@ -537,6 +553,8 @@ struct spi_master {
 	/* dummy data for full duplex devices */
 	void			*dummy_rx;
 	void			*dummy_tx;
+
+	int (*fw_translate_cs)(struct spi_master *master, unsigned cs);
 };
 
 static inline void *spi_master_get_devdata(struct spi_master *master)
@@ -582,6 +600,38 @@ extern void spi_unregister_master(struct spi_master *master);
 
 extern struct spi_master *spi_busnum_to_master(u16 busnum);
 
+/*
+ * SPI resource management while processing a SPI message
+ */
+
+typedef void (*spi_res_release_t)(struct spi_master *master,
+				  struct spi_message *msg,
+				  void *res);
+
+/**
+ * struct spi_res - spi resource management structure
+ * @entry:   list entry
+ * @release: release code called prior to freeing this resource
+ * @data:    extra data allocated for the specific use-case
+ *
+ * this is based on ideas from devres, but focused on life-cycle
+ * management during spi_message processing
+ */
+struct spi_res {
+	struct list_head        entry;
+	spi_res_release_t       release;
+	unsigned long long      data[]; /* guarantee ull alignment */
+};
+
+extern void *spi_res_alloc(struct spi_device *spi,
+			   spi_res_release_t release,
+			   size_t size, gfp_t gfp);
+extern void spi_res_add(struct spi_message *message, void *res);
+extern void spi_res_free(void *res);
+
+extern void spi_res_release(struct spi_master *master,
+			    struct spi_message *message);
+
 /*---------------------------------------------------------------------------*/
 
 /*
@@ -720,6 +770,7 @@ struct spi_transfer {
  * @status: zero for success, else negative errno
  * @queue: for use by whichever driver currently owns the message
  * @state: for use by whichever driver currently owns the message
+ * @resources: for resource management when the spi message is processed
  *
  * A @spi_message is used to execute an atomic sequence of data transfers,
  * each represented by a struct spi_transfer.  The sequence is "atomic"
@@ -766,11 +817,15 @@ struct spi_message {
 	 */
 	struct list_head	queue;
 	void			*state;
+
+	/* list of spi_res reources when the spi message is processed */
+	struct list_head        resources;
 };
 
 static inline void spi_message_init_no_memset(struct spi_message *m)
 {
 	INIT_LIST_HEAD(&m->transfers);
+	INIT_LIST_HEAD(&m->resources);
 }
 
 static inline void spi_message_init(struct spi_message *m)
@@ -854,6 +909,60 @@ spi_max_transfer_size(struct spi_device *spi)
 
 /*---------------------------------------------------------------------------*/
 
+/* SPI transfer replacement methods which make use of spi_res */
+
+struct spi_replaced_transfers;
+typedef void (*spi_replaced_release_t)(struct spi_master *master,
+				       struct spi_message *msg,
+				       struct spi_replaced_transfers *res);
+/**
+ * struct spi_replaced_transfers - structure describing the spi_transfer
+ *                                 replacements that have occurred
+ *                                 so that they can get reverted
+ * @release:            some extra release code to get executed prior to
+ *                      relasing this structure
+ * @extradata:          pointer to some extra data if requested or NULL
+ * @replaced_transfers: transfers that have been replaced and which need
+ *                      to get restored
+ * @replaced_after:     the transfer after which the @replaced_transfers
+ *                      are to get re-inserted
+ * @inserted:           number of transfers inserted
+ * @inserted_transfers: array of spi_transfers of array-size @inserted,
+ *                      that have been replacing replaced_transfers
+ *
+ * note: that @extradata will point to @inserted_transfers[@inserted]
+ * if some extra allocation is requested, so alignment will be the same
+ * as for spi_transfers
+ */
+struct spi_replaced_transfers {
+	spi_replaced_release_t release;
+	void *extradata;
+	struct list_head replaced_transfers;
+	struct list_head *replaced_after;
+	size_t inserted;
+	struct spi_transfer inserted_transfers[];
+};
+
+extern struct spi_replaced_transfers *spi_replace_transfers(
+	struct spi_message *msg,
+	struct spi_transfer *xfer_first,
+	size_t remove,
+	size_t insert,
+	spi_replaced_release_t release,
+	size_t extradatasize,
+	gfp_t gfp);
+
+/*---------------------------------------------------------------------------*/
+
+/* SPI transfer transformation methods */
+
+extern int spi_split_transfers_maxsize(struct spi_master *master,
+				       struct spi_message *msg,
+				       size_t maxsize,
+				       gfp_t gfp);
+
+/*---------------------------------------------------------------------------*/
+
 /* All these synchronous SPI transfer routines are utilities layered
  * over the core async transfer primitive.  Here, "synchronous" means
  * they will sleep uninterruptibly until the async transfer completes.
@@ -1019,6 +1128,42 @@ static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd)
 	return be16_to_cpu(result);
 }
 
+/**
+ * struct spi_flash_read_message - flash specific information for
+ * spi-masters that provide accelerated flash read interfaces
+ * @buf: buffer to read data
+ * @from: offset within the flash from where data is to be read
+ * @len: length of data to be read
+ * @retlen: actual length of data read
+ * @read_opcode: read_opcode to be used to communicate with flash
+ * @addr_width: number of address bytes
+ * @dummy_bytes: number of dummy bytes
+ * @opcode_nbits: number of lines to send opcode
+ * @addr_nbits: number of lines to send address
+ * @data_nbits: number of lines for data
+ */
+struct spi_flash_read_message {
+	void *buf;
+	loff_t from;
+	size_t len;
+	size_t retlen;
+	u8 read_opcode;
+	u8 addr_width;
+	u8 dummy_bytes;
+	u8 opcode_nbits;
+	u8 addr_nbits;
+	u8 data_nbits;
+};
+
+/* SPI core interface for flash read support */
+static inline bool spi_flash_read_supported(struct spi_device *spi)
+{
+	return spi->master->spi_flash_read ? true : false;
+}
+
+int spi_flash_read(struct spi_device *spi,
+		   struct spi_flash_read_message *msg);
+
 /*---------------------------------------------------------------------------*/
 
 /*