DMA: TXx9 Soc DMA Controller driver

This patch adds support for the integrated DMAC of the TXx9 family.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/txx9/dmac.h

+/*
+ * TXx9 SoC DMA Controller
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_TXX9_DMAC_H
+#define __ASM_TXX9_DMAC_H
+
+#include <linux/dmaengine.h>
+
+#define TXX9_DMA_MAX_NR_CHANNELS	4
+
+/**
+ * struct txx9dmac_platform_data - Controller configuration parameters
+ * @memcpy_chan: Channel used for DMA_MEMCPY
+ * @have_64bit_regs: DMAC have 64 bit registers
+ */
+struct txx9dmac_platform_data {
+	int	memcpy_chan;
+	bool	have_64bit_regs;
+};
+
+/**
+ * struct txx9dmac_chan_platform_data - Channel configuration parameters
+ * @dmac_dev: A platform device for DMAC
+ */
+struct txx9dmac_chan_platform_data {
+	struct platform_device *dmac_dev;
+};
+
+/**
+ * struct txx9dmac_slave - Controller-specific information about a slave
+ * @tx_reg: physical address of data register used for
+ *	memory-to-peripheral transfers
+ * @rx_reg: physical address of data register used for
+ *	peripheral-to-memory transfers
+ * @reg_width: peripheral register width
+ */
+struct txx9dmac_slave {
+	u64		tx_reg;
+	u64		rx_reg;
+	unsigned int	reg_width;
+};
+
+#endif /* __ASM_TXX9_DMAC_H */

drivers/dma/Kconfig

@@ -81,6 +81,14 @@ config MX3_IPU_IRQS
 	  To avoid bloating the irq_desc[] array we allocate a sufficient
 	  number of IRQ slots and map them dynamically to specific sources.
 
+config TXX9_DMAC
+	tristate "Toshiba TXx9 SoC DMA support"
+	depends on MACH_TX49XX || MACH_TX39XX
+	select DMA_ENGINE
+	help
+	  Support the TXx9 SoC internal DMA controller.  This can be
+	  integrated in chips such as the Toshiba TX4927/38/39.
+
 config DMA_ENGINE
 	bool
 

drivers/dma/Makefile

@@ -8,3 +8,4 @@ obj-$(CONFIG_FSL_DMA) += fsldma.o
 obj-$(CONFIG_MV_XOR) += mv_xor.o
 obj-$(CONFIG_DW_DMAC) += dw_dmac.o
 obj-$(CONFIG_MX3_IPU) += ipu/
+obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o

drivers/dma/txx9dmac.h

+/*
+ * Driver for the TXx9 SoC DMA Controller
+ *
+ * Copyright (C) 2009 Atsushi Nemoto
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef TXX9DMAC_H
+#define TXX9DMAC_H
+
+#include <linux/dmaengine.h>
+#include <asm/txx9/dmac.h>
+
+/*
+ * Design Notes:
+ *
+ * This DMAC have four channels and one FIFO buffer.  Each channel can
+ * be configured for memory-memory or device-memory transfer, but only
+ * one channel can do alignment-free memory-memory transfer at a time
+ * while the channel should occupy the FIFO buffer for effective
+ * transfers.
+ *
+ * Instead of dynamically assign the FIFO buffer to channels, I chose
+ * make one dedicated channel for memory-memory transfer.  The
+ * dedicated channel is public.  Other channels are private and used
+ * for slave transfer.  Some devices in the SoC are wired to certain
+ * DMA channel.
+ */
+
+#ifdef CONFIG_MACH_TX49XX
+static inline bool txx9_dma_have_SMPCHN(void)
+{
+	return true;
+}
+#define TXX9_DMA_USE_SIMPLE_CHAIN
+#else
+static inline bool txx9_dma_have_SMPCHN(void)
+{
+	return false;
+}
+#endif
+
+#ifdef __LITTLE_ENDIAN
+#ifdef CONFIG_MACH_TX49XX
+#define CCR_LE	TXX9_DMA_CCR_LE
+#define MCR_LE	0
+#else
+#define CCR_LE	0
+#define MCR_LE	TXX9_DMA_MCR_LE
+#endif
+#else
+#define CCR_LE	0
+#define MCR_LE	0
+#endif
+
+/*
+ * Redefine this macro to handle differences between 32- and 64-bit
+ * addressing, big vs. little endian, etc.
+ */
+#ifdef __BIG_ENDIAN
+#define TXX9_DMA_REG32(name)		u32 __pad_##name; u32 name
+#else
+#define TXX9_DMA_REG32(name)		u32 name; u32 __pad_##name
+#endif
+
+/* Hardware register definitions. */
+struct txx9dmac_cregs {
+#if defined(CONFIG_32BIT) && !defined(CONFIG_64BIT_PHYS_ADDR)
+	TXX9_DMA_REG32(CHAR);	/* Chain Address Register */
+#else
+	u64 CHAR;		/* Chain Address Register */
+#endif
+	u64 SAR;		/* Source Address Register */
+	u64 DAR;		/* Destination Address Register */
+	TXX9_DMA_REG32(CNTR);	/* Count Register */
+	TXX9_DMA_REG32(SAIR);	/* Source Address Increment Register */
+	TXX9_DMA_REG32(DAIR);	/* Destination Address Increment Register */
+	TXX9_DMA_REG32(CCR);	/* Channel Control Register */
+	TXX9_DMA_REG32(CSR);	/* Channel Status Register */
+};
+struct txx9dmac_cregs32 {
+	u32 CHAR;
+	u32 SAR;
+	u32 DAR;
+	u32 CNTR;
+	u32 SAIR;
+	u32 DAIR;
+	u32 CCR;
+	u32 CSR;
+};
+
+struct txx9dmac_regs {
+	/* per-channel registers */
+	struct txx9dmac_cregs	CHAN[TXX9_DMA_MAX_NR_CHANNELS];
+	u64	__pad[9];
+	u64	MFDR;		/* Memory Fill Data Register */
+	TXX9_DMA_REG32(MCR);	/* Master Control Register */
+};
+struct txx9dmac_regs32 {
+	struct txx9dmac_cregs32	CHAN[TXX9_DMA_MAX_NR_CHANNELS];
+	u32	__pad[9];
+	u32	MFDR;
+	u32	MCR;
+};
+
+/* bits for MCR */
+#define TXX9_DMA_MCR_EIS(ch)	(0x10000000<<(ch))
+#define TXX9_DMA_MCR_DIS(ch)	(0x01000000<<(ch))
+#define TXX9_DMA_MCR_RSFIF	0x00000080
+#define TXX9_DMA_MCR_FIFUM(ch)	(0x00000008<<(ch))
+#define TXX9_DMA_MCR_LE		0x00000004
+#define TXX9_DMA_MCR_RPRT	0x00000002
+#define TXX9_DMA_MCR_MSTEN	0x00000001
+
+/* bits for CCRn */
+#define TXX9_DMA_CCR_IMMCHN	0x20000000
+#define TXX9_DMA_CCR_USEXFSZ	0x10000000
+#define TXX9_DMA_CCR_LE		0x08000000
+#define TXX9_DMA_CCR_DBINH	0x04000000
+#define TXX9_DMA_CCR_SBINH	0x02000000
+#define TXX9_DMA_CCR_CHRST	0x01000000
+#define TXX9_DMA_CCR_RVBYTE	0x00800000
+#define TXX9_DMA_CCR_ACKPOL	0x00400000
+#define TXX9_DMA_CCR_REQPL	0x00200000
+#define TXX9_DMA_CCR_EGREQ	0x00100000
+#define TXX9_DMA_CCR_CHDN	0x00080000
+#define TXX9_DMA_CCR_DNCTL	0x00060000
+#define TXX9_DMA_CCR_EXTRQ	0x00010000
+#define TXX9_DMA_CCR_INTRQD	0x0000e000
+#define TXX9_DMA_CCR_INTENE	0x00001000
+#define TXX9_DMA_CCR_INTENC	0x00000800
+#define TXX9_DMA_CCR_INTENT	0x00000400
+#define TXX9_DMA_CCR_CHNEN	0x00000200
+#define TXX9_DMA_CCR_XFACT	0x00000100
+#define TXX9_DMA_CCR_SMPCHN	0x00000020
+#define TXX9_DMA_CCR_XFSZ(order)	(((order) << 2) & 0x0000001c)
+#define TXX9_DMA_CCR_XFSZ_1	TXX9_DMA_CCR_XFSZ(0)
+#define TXX9_DMA_CCR_XFSZ_2	TXX9_DMA_CCR_XFSZ(1)
+#define TXX9_DMA_CCR_XFSZ_4	TXX9_DMA_CCR_XFSZ(2)
+#define TXX9_DMA_CCR_XFSZ_8	TXX9_DMA_CCR_XFSZ(3)
+#define TXX9_DMA_CCR_XFSZ_X4	TXX9_DMA_CCR_XFSZ(4)
+#define TXX9_DMA_CCR_XFSZ_X8	TXX9_DMA_CCR_XFSZ(5)
+#define TXX9_DMA_CCR_XFSZ_X16	TXX9_DMA_CCR_XFSZ(6)
+#define TXX9_DMA_CCR_XFSZ_X32	TXX9_DMA_CCR_XFSZ(7)
+#define TXX9_DMA_CCR_MEMIO	0x00000002
+#define TXX9_DMA_CCR_SNGAD	0x00000001
+
+/* bits for CSRn */
+#define TXX9_DMA_CSR_CHNEN	0x00000400
+#define TXX9_DMA_CSR_STLXFER	0x00000200
+#define TXX9_DMA_CSR_XFACT	0x00000100
+#define TXX9_DMA_CSR_ABCHC	0x00000080
+#define TXX9_DMA_CSR_NCHNC	0x00000040
+#define TXX9_DMA_CSR_NTRNFC	0x00000020
+#define TXX9_DMA_CSR_EXTDN	0x00000010
+#define TXX9_DMA_CSR_CFERR	0x00000008
+#define TXX9_DMA_CSR_CHERR	0x00000004
+#define TXX9_DMA_CSR_DESERR	0x00000002
+#define TXX9_DMA_CSR_SORERR	0x00000001
+
+struct txx9dmac_chan {
+	struct dma_chan		chan;
+	struct dma_device	dma;
+	struct txx9dmac_dev	*ddev;
+	void __iomem		*ch_regs;
+	struct tasklet_struct	tasklet;
+	int			irq;
+	u32			ccr;
+
+	spinlock_t		lock;
+
+	/* these other elements are all protected by lock */
+	dma_cookie_t		completed;
+	struct list_head	active_list;
+	struct list_head	queue;
+	struct list_head	free_list;
+
+	unsigned int		descs_allocated;
+};
+
+struct txx9dmac_dev {
+	void __iomem		*regs;
+	struct tasklet_struct	tasklet;
+	int			irq;
+	struct txx9dmac_chan	*chan[TXX9_DMA_MAX_NR_CHANNELS];
+	bool			have_64bit_regs;
+	unsigned int		descsize;
+};
+
+static inline bool __is_dmac64(const struct txx9dmac_dev *ddev)
+{
+	return ddev->have_64bit_regs;
+}
+
+static inline bool is_dmac64(const struct txx9dmac_chan *dc)
+{
+	return __is_dmac64(dc->ddev);
+}
+
+#ifdef TXX9_DMA_USE_SIMPLE_CHAIN
+/* Hardware descriptor definition. (for simple-chain) */
+struct txx9dmac_hwdesc {
+#if defined(CONFIG_32BIT) && !defined(CONFIG_64BIT_PHYS_ADDR)
+	TXX9_DMA_REG32(CHAR);
+#else
+	u64 CHAR;
+#endif
+	u64 SAR;
+	u64 DAR;
+	TXX9_DMA_REG32(CNTR);
+};
+struct txx9dmac_hwdesc32 {
+	u32 CHAR;
+	u32 SAR;
+	u32 DAR;
+	u32 CNTR;
+};
+#else
+#define txx9dmac_hwdesc txx9dmac_cregs
+#define txx9dmac_hwdesc32 txx9dmac_cregs32
+#endif
+
+struct txx9dmac_desc {
+	/* FIRST values the hardware uses */
+	union {
+		struct txx9dmac_hwdesc hwdesc;
+		struct txx9dmac_hwdesc32 hwdesc32;
+	};
+
+	/* THEN values for driver housekeeping */
+	struct list_head		desc_node ____cacheline_aligned;
+	struct dma_async_tx_descriptor	txd;
+	size_t				len;
+};
+
+#ifdef TXX9_DMA_USE_SIMPLE_CHAIN
+
+static inline bool txx9dmac_chan_INTENT(struct txx9dmac_chan *dc)
+{
+	return (dc->ccr & TXX9_DMA_CCR_INTENT) != 0;
+}
+
+static inline void txx9dmac_chan_set_INTENT(struct txx9dmac_chan *dc)
+{
+	dc->ccr |= TXX9_DMA_CCR_INTENT;
+}
+
+static inline void txx9dmac_desc_set_INTENT(struct txx9dmac_dev *ddev,
+					    struct txx9dmac_desc *desc)
+{
+}
+
+static inline void txx9dmac_chan_set_SMPCHN(struct txx9dmac_chan *dc)
+{
+	dc->ccr |= TXX9_DMA_CCR_SMPCHN;
+}
+
+static inline void txx9dmac_desc_set_nosimple(struct txx9dmac_dev *ddev,
+					      struct txx9dmac_desc *desc,
+					      u32 sair, u32 dair, u32 ccr)
+{
+}
+
+#else /* TXX9_DMA_USE_SIMPLE_CHAIN */
+
+static inline bool txx9dmac_chan_INTENT(struct txx9dmac_chan *dc)
+{
+	return true;
+}
+
+static void txx9dmac_chan_set_INTENT(struct txx9dmac_chan *dc)
+{
+}
+
+static inline void txx9dmac_desc_set_INTENT(struct txx9dmac_dev *ddev,
+					    struct txx9dmac_desc *desc)
+{
+	if (__is_dmac64(ddev))
+		desc->hwdesc.CCR |= TXX9_DMA_CCR_INTENT;
+	else
+		desc->hwdesc32.CCR |= TXX9_DMA_CCR_INTENT;
+}
+
+static inline void txx9dmac_chan_set_SMPCHN(struct txx9dmac_chan *dc)
+{
+}
+
+static inline void txx9dmac_desc_set_nosimple(struct txx9dmac_dev *ddev,
+					      struct txx9dmac_desc *desc,
+					      u32 sai, u32 dai, u32 ccr)
+{
+	if (__is_dmac64(ddev)) {
+		desc->hwdesc.SAIR = sai;
+		desc->hwdesc.DAIR = dai;
+		desc->hwdesc.CCR = ccr;
+	} else {
+		desc->hwdesc32.SAIR = sai;
+		desc->hwdesc32.DAIR = dai;
+		desc->hwdesc32.CCR = ccr;
+	}
+}
+
+#endif /* TXX9_DMA_USE_SIMPLE_CHAIN */
+
+#endif /* TXX9DMAC_H */