soc: ti: add Keystone Navigator DMA support

The Keystone Navigator DMA driver sets up the dma channels and flows for
the QMSS(Queue Manager SubSystem) who triggers the actual data movements
across clients using destination queues. Every client modules like
NETCP(Network Coprocessor), SRIO(Serial Rapid IO) and CRYPTO
Engines has its own instance of packet dma hardware. QMSS has also
an internal packet DMA module which is used as an infrastructure
DMA with zero copy.

Initially this driver was proposed as DMA engine driver but since the
hardware is not typical DMA engine and hence doesn't comply with typical
DMA engine driver needs, that approach was naked. Link to that
discussion -
	https://lkml.org/lkml/2014/3/18/340

As aligned, now we pair the Navigator DMA with its companion Navigator
QMSS subsystem driver.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sandeep Nair <sandeep_n@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

drivers/soc/ti/Kconfig

@@ -18,4 +18,14 @@ config KEYSTONE_NAVIGATOR_QMSS
 
 	  If unsure, say N.
 
+config KEYSTONE_NAVIGATOR_DMA
+	tristate "TI Keystone Navigator Packet DMA support"
+	depends on ARCH_KEYSTONE
+	help
+	  Say y tp enable support for the Keystone Navigator Packet DMA on
+	  on Keystone family of devices. It sets up the dma channels for the
+	  Queue Manager Sub System.
+
+	  If unsure, say N.
+
 endif # SOC_TI

drivers/soc/ti/Makefile

@@ -2,3 +2,4 @@
 # TI Keystone SOC drivers
 #
 obj-$(CONFIG_KEYSTONE_NAVIGATOR_QMSS)	+= knav_qmss_queue.o knav_qmss_acc.o
+obj-$(CONFIG_KEYSTONE_NAVIGATOR_DMA)	+= knav_dma.o

include/linux/soc/ti/knav_dma.h

+/*
+ * Copyright (C) 2014 Texas Instruments Incorporated
+ * Authors:	Sandeep Nair <sandeep_n@ti.com
+ *		Cyril Chemparathy <cyril@ti.com
+		Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __SOC_TI_KEYSTONE_NAVIGATOR_DMA_H__
+#define __SOC_TI_KEYSTONE_NAVIGATOR_DMA_H__
+
+/*
+ * PKTDMA descriptor manipulation macros for host packet descriptor
+ */
+#define MASK(x)					(BIT(x) - 1)
+#define KNAV_DMA_DESC_PKT_LEN_MASK		MASK(22)
+#define KNAV_DMA_DESC_PKT_LEN_SHIFT		0
+#define KNAV_DMA_DESC_PS_INFO_IN_SOP		BIT(22)
+#define KNAV_DMA_DESC_PS_INFO_IN_DESC		0
+#define KNAV_DMA_DESC_TAG_MASK			MASK(8)
+#define KNAV_DMA_DESC_SAG_HI_SHIFT		24
+#define KNAV_DMA_DESC_STAG_LO_SHIFT		16
+#define KNAV_DMA_DESC_DTAG_HI_SHIFT		8
+#define KNAV_DMA_DESC_DTAG_LO_SHIFT		0
+#define KNAV_DMA_DESC_HAS_EPIB			BIT(31)
+#define KNAV_DMA_DESC_NO_EPIB			0
+#define KNAV_DMA_DESC_PSLEN_SHIFT		24
+#define KNAV_DMA_DESC_PSLEN_MASK		MASK(6)
+#define KNAV_DMA_DESC_ERR_FLAG_SHIFT		20
+#define KNAV_DMA_DESC_ERR_FLAG_MASK		MASK(4)
+#define KNAV_DMA_DESC_PSFLAG_SHIFT		16
+#define KNAV_DMA_DESC_PSFLAG_MASK		MASK(4)
+#define KNAV_DMA_DESC_RETQ_SHIFT		0
+#define KNAV_DMA_DESC_RETQ_MASK			MASK(14)
+#define KNAV_DMA_DESC_BUF_LEN_MASK		MASK(22)
+
+#define KNAV_DMA_NUM_EPIB_WORDS			4
+#define KNAV_DMA_NUM_PS_WORDS			16
+#define KNAV_DMA_FDQ_PER_CHAN			4
+
+/* Tx channel scheduling priority */
+enum knav_dma_tx_priority {
+	DMA_PRIO_HIGH	= 0,
+	DMA_PRIO_MED_H,
+	DMA_PRIO_MED_L,
+	DMA_PRIO_LOW
+};
+
+/* Rx channel error handling mode during buffer starvation */
+enum knav_dma_rx_err_mode {
+	DMA_DROP = 0,
+	DMA_RETRY
+};
+
+/* Rx flow size threshold configuration */
+enum knav_dma_rx_thresholds {
+	DMA_THRESH_NONE		= 0,
+	DMA_THRESH_0		= 1,
+	DMA_THRESH_0_1		= 3,
+	DMA_THRESH_0_1_2	= 7
+};
+
+/* Descriptor type */
+enum knav_dma_desc_type {
+	DMA_DESC_HOST = 0,
+	DMA_DESC_MONOLITHIC = 2
+};
+
+/**
+ * struct knav_dma_tx_cfg:	Tx channel configuration
+ * @filt_einfo:			Filter extended packet info
+ * @filt_pswords:		Filter PS words present
+ * @knav_dma_tx_priority:	Tx channel scheduling priority
+ */
+struct knav_dma_tx_cfg {
+	bool				filt_einfo;
+	bool				filt_pswords;
+	enum knav_dma_tx_priority	priority;
+};
+
+/**
+ * struct knav_dma_rx_cfg:	Rx flow configuration
+ * @einfo_present:		Extended packet info present
+ * @psinfo_present:		PS words present
+ * @knav_dma_rx_err_mode:	Error during buffer starvation
+ * @knav_dma_desc_type:	Host or Monolithic desc
+ * @psinfo_at_sop:		PS word located at start of packet
+ * @sop_offset:			Start of packet offset
+ * @dst_q:			Destination queue for a given flow
+ * @thresh:			Rx flow size threshold
+ * @fdq[]:			Free desc Queue array
+ * @sz_thresh0:			RX packet size threshold 0
+ * @sz_thresh1:			RX packet size threshold 1
+ * @sz_thresh2:			RX packet size threshold 2
+ */
+struct knav_dma_rx_cfg {
+	bool				einfo_present;
+	bool				psinfo_present;
+	enum knav_dma_rx_err_mode	err_mode;
+	enum knav_dma_desc_type		desc_type;
+	bool				psinfo_at_sop;
+	unsigned int			sop_offset;
+	unsigned int			dst_q;
+	enum knav_dma_rx_thresholds	thresh;
+	unsigned int			fdq[KNAV_DMA_FDQ_PER_CHAN];
+	unsigned int			sz_thresh0;
+	unsigned int			sz_thresh1;
+	unsigned int			sz_thresh2;
+};
+
+/**
+ * struct knav_dma_cfg:	Pktdma channel configuration
+ * @sl_cfg:			Slave configuration
+ * @tx:				Tx channel configuration
+ * @rx:				Rx flow configuration
+ */
+struct knav_dma_cfg {
+	enum dma_transfer_direction direction;
+	union {
+		struct knav_dma_tx_cfg	tx;
+		struct knav_dma_rx_cfg	rx;
+	} u;
+};
+
+/**
+ * struct knav_dma_desc:	Host packet descriptor layout
+ * @desc_info:			Descriptor information like id, type, length
+ * @tag_info:			Flow tag info written in during RX
+ * @packet_info:		Queue Manager, policy, flags etc
+ * @buff_len:			Buffer length in bytes
+ * @buff:			Buffer pointer
+ * @next_desc:			For chaining the descriptors
+ * @orig_len:			length since 'buff_len' can be overwritten
+ * @orig_buff:			buff pointer since 'buff' can be overwritten
+ * @epib:			Extended packet info block
+ * @psdata:			Protocol specific
+ */
+struct knav_dma_desc {
+	u32	desc_info;
+	u32	tag_info;
+	u32	packet_info;
+	u32	buff_len;
+	u32	buff;
+	u32	next_desc;
+	u32	orig_len;
+	u32	orig_buff;
+	u32	epib[KNAV_DMA_NUM_EPIB_WORDS];
+	u32	psdata[KNAV_DMA_NUM_PS_WORDS];
+	u32	pad[4];
+} ____cacheline_aligned;
+
+#ifdef CONFIG_KEYSTONE_NAVIGATOR_DMA
+void *knav_dma_open_channel(struct device *dev, const char *name,
+				struct knav_dma_cfg *config);
+void knav_dma_close_channel(void *channel);
+#else
+static inline void *knav_dma_open_channel(struct device *dev, const char *name,
+				struct knav_dma_cfg *config)
+{
+	return (void *) NULL;
+}
+static inline void knav_dma_close_channel(void *channel)
+{}
+
+#endif
+
+#endif /* __SOC_TI_KEYSTONE_NAVIGATOR_DMA_H__ */