[PATCH v9 2/2] dmaengine: Add Xilinx zynqmp dma engine driver support

Appana Durga Kedareswara Rao appana.durga.rao at xilinx.com
Sun May 29 21:17:16 PDT 2016


Ping!!

> -----Original Message-----
> From: Kedareswara rao Appana [mailto:appana.durga.rao at xilinx.com]
> Sent: Friday, May 13, 2016 12:34 PM
> To: robh+dt at kernel.org; pawel.moll at arm.com; mark.rutland at arm.com;
> ijc+devicetree at hellion.org.uk; galak at codeaurora.org; Michal Simek
> <michals at xilinx.com>; Soren Brinkmann <sorenb at xilinx.com>;
> vinod.koul at intel.com; dan.j.williams at intel.com; Appana Durga Kedareswara
> Rao <appanad at xilinx.com>; moritz.fischer at ettus.com;
> laurent.pinchart at ideasonboard.com; luis at debethencourt.com
> Cc: devicetree at vger.kernel.org; linux-arm-kernel at lists.infradead.org; linux-
> kernel at vger.kernel.org; dmaengine at vger.kernel.org; Punnaiah Choudary
> Kalluri <punnaia at xilinx.com>
> Subject: [PATCH v9 2/2] dmaengine: Add Xilinx zynqmp dma engine driver
> support
> 
> Added the driver for zynqmp dma engine used in Zynq
> UltraScale+ MPSoC. This dma controller supports memory to memory
> and memory to I/O buffer transfers.
> 
> Signed-off-by: Punnaiah Choudary Kalluri <punnaia at xilinx.com>
> Signed-off-by: Kedareswara rao Appana <appanad at xilinx.com>
> ---
> Changes for v9:
> - Derive the include sg software runtime configuration parameter
>   through config strucutre as suggested by the Lars.
> Changes for v8:
> - Derive the software runtime configuration parameters
>   through config strucutre and configure them during transfer
>   as suggested by the Lars.
> Changes for v7:
> - Fixed kbuild compilation warnings.
> - Fixed {src,dst}_addr_widths are supposed to be a bitmask of
>   supported slave device widths as suggested by Rob.
> Changes in v6:
> - Removed unnecessary axcache properties from the driver
> - Fixed compilation issues
> Changes in v5:
> - Removed in_interrupt check from the tasklet cleanup as
>   suggested by the vinod/lars.
> Changes in v4:
> - Modified the defines to start with ZYNQMP_DMA perfix
> - Changed the zynqmp_dma_alloc_chan_resources to return number of
>   allocated descriptors
> - Changed the zynqmp_dma_device variable name
> - Released the locks before calling user callback
> - freeup irq in zynqmp_dma_chan_remove function.
> Changes in v3:
> - Modified the zynqmp_dma_chan_is_idle function return type to bool Changes
> in v2:
> - Corrected the function header documentation
> - Framework expects bus-width value in bytes. so, fixed it
> - Removed magic numbers for bus-width
> 
>  drivers/dma/Kconfig             |    6 +
>  drivers/dma/xilinx/Makefile     |    1 +
>  drivers/dma/xilinx/zynqmp_dma.c | 1262
> +++++++++++++++++++++++++++++++++++++++
>  include/linux/dma/xilinx_dma.h  |   21 +-
>  4 files changed, 1289 insertions(+), 1 deletion(-)  create mode 100644
> drivers/dma/xilinx/zynqmp_dma.c
> 
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index f843dd5..6758417
> 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -527,6 +527,12 @@ config ZX_DMA
>  	help
>  	  Support the DMA engine for ZTE ZX296702 platform devices.
> 
> +config XILINX_ZYNQMP_DMA
> +	tristate "Xilinx ZynqMP DMA Engine"
> +	depends on (ARCH_ZYNQ || MICROBLAZE || ARM64)
> +	select DMA_ENGINE
> +	help
> +	  Enable support for Xilinx ZynqMP DMA controller.
> 
>  # driver files
>  source "drivers/dma/bestcomm/Kconfig"
> diff --git a/drivers/dma/xilinx/Makefile b/drivers/dma/xilinx/Makefile index
> 3c4e9f2..95469dc 100644
> --- a/drivers/dma/xilinx/Makefile
> +++ b/drivers/dma/xilinx/Makefile
> @@ -1 +1,2 @@
>  obj-$(CONFIG_XILINX_VDMA) += xilinx_vdma.o
> +obj-$(CONFIG_XILINX_ZYNQMP_DMA) += zynqmp_dma.o
> diff --git a/drivers/dma/xilinx/zynqmp_dma.c
> b/drivers/dma/xilinx/zynqmp_dma.c new file mode 100644 index
> 0000000..9964dcb
> --- /dev/null
> +++ b/drivers/dma/xilinx/zynqmp_dma.c
> @@ -0,0 +1,1262 @@
> +/*
> + * DMA driver for Xilinx ZynqMP DMA Engine
> + *
> + * Copyright (C) 2016 Xilinx, Inc. All rights reserved.
> + *
> + * 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.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dma/xilinx_dma.h>
> +#include <linux/dmaengine.h>
> +#include <linux/dmapool.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/of_dma.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_platform.h>
> +#include <linux/slab.h>
> +#include <linux/clk.h>
> +
> +#include "../dmaengine.h"
> +
> +/* Register Offsets */
> +#define ZYNQMP_DMA_ISR			0x100
> +#define ZYNQMP_DMA_IMR			0x104
> +#define ZYNQMP_DMA_IER			0x108
> +#define ZYNQMP_DMA_IDS			0x10C
> +#define ZYNQMP_DMA_CTRL0		0x110
> +#define ZYNQMP_DMA_CTRL1		0x114
> +#define ZYNQMP_DMA_DATA_ATTR		0x120
> +#define ZYNQMP_DMA_DSCR_ATTR		0x124
> +#define ZYNQMP_DMA_SRC_DSCR_WRD0	0x128
> +#define ZYNQMP_DMA_SRC_DSCR_WRD1	0x12C
> +#define ZYNQMP_DMA_SRC_DSCR_WRD2	0x130
> +#define ZYNQMP_DMA_SRC_DSCR_WRD3	0x134
> +#define ZYNQMP_DMA_DST_DSCR_WRD0	0x138
> +#define ZYNQMP_DMA_DST_DSCR_WRD1	0x13C
> +#define ZYNQMP_DMA_DST_DSCR_WRD2	0x140
> +#define ZYNQMP_DMA_DST_DSCR_WRD3	0x144
> +#define ZYNQMP_DMA_SRC_START_LSB	0x158
> +#define ZYNQMP_DMA_SRC_START_MSB	0x15C
> +#define ZYNQMP_DMA_DST_START_LSB	0x160
> +#define ZYNQMP_DMA_DST_START_MSB	0x164
> +#define ZYNQMP_DMA_RATE_CTRL		0x18C
> +#define ZYNQMP_DMA_IRQ_SRC_ACCT		0x190
> +#define ZYNQMP_DMA_IRQ_DST_ACCT		0x194
> +#define ZYNQMP_DMA_CTRL2		0x200
> +
> +/* Interrupt registers bit field definitions */
> +#define ZYNQMP_DMA_DONE			BIT(10)
> +#define ZYNQMP_DMA_AXI_WR_DATA		BIT(9)
> +#define ZYNQMP_DMA_AXI_RD_DATA		BIT(8)
> +#define ZYNQMP_DMA_AXI_RD_DST_DSCR	BIT(7)
> +#define ZYNQMP_DMA_AXI_RD_SRC_DSCR	BIT(6)
> +#define ZYNQMP_DMA_IRQ_DST_ACCT_ERR	BIT(5)
> +#define ZYNQMP_DMA_IRQ_SRC_ACCT_ERR	BIT(4)
> +#define ZYNQMP_DMA_BYTE_CNT_OVRFL	BIT(3)
> +#define ZYNQMP_DMA_DST_DSCR_DONE	BIT(2)
> +#define ZYNQMP_DMA_INV_APB		BIT(0)
> +
> +/* Control 0 register bit field definitions */
> +#define ZYNQMP_DMA_OVR_FETCH		BIT(7)
> +#define ZYNQMP_DMA_POINT_TYPE_SG	BIT(6)
> +#define ZYNQMP_DMA_RATE_CTRL_EN		BIT(3)
> +
> +/* Control 1 register bit field definitions */
> +#define ZYNQMP_DMA_SRC_ISSUE		GENMASK(4, 0)
> +
> +/* Data Attribute register bit field definitions */
> +#define ZYNQMP_DMA_ARBURST		GENMASK(27, 26)
> +#define ZYNQMP_DMA_ARCACHE		GENMASK(25, 22)
> +#define ZYNQMP_DMA_ARCACHE_OFST		22
> +#define ZYNQMP_DMA_ARQOS		GENMASK(21, 18)
> +#define ZYNQMP_DMA_ARQOS_OFST		18
> +#define ZYNQMP_DMA_ARLEN		GENMASK(17, 14)
> +#define ZYNQMP_DMA_ARLEN_OFST		14
> +#define ZYNQMP_DMA_AWBURST		GENMASK(13, 12)
> +#define ZYNQMP_DMA_AWCACHE		GENMASK(11, 8)
> +#define ZYNQMP_DMA_AWCACHE_OFST		8
> +#define ZYNQMP_DMA_AWQOS		GENMASK(7, 4)
> +#define ZYNQMP_DMA_AWQOS_OFST		4
> +#define ZYNQMP_DMA_AWLEN		GENMASK(3, 0)
> +#define ZYNQMP_DMA_AWLEN_OFST		0
> +
> +/* Descriptor Attribute register bit field definitions */
> +#define ZYNQMP_DMA_AXCOHRNT		BIT(8)
> +#define ZYNQMP_DMA_AXCACHE		GENMASK(7, 4)
> +#define ZYNQMP_DMA_AXCACHE_OFST		4
> +#define ZYNQMP_DMA_AXQOS		GENMASK(3, 0)
> +#define ZYNQMP_DMA_AXQOS_OFST		0
> +
> +/* Control register 2 bit field definitions */
> +#define ZYNQMP_DMA_ENABLE		BIT(0)
> +
> +/* Buffer Descriptor definitions */
> +#define ZYNQMP_DMA_DESC_CTRL_STOP	0x10
> +#define ZYNQMP_DMA_DESC_CTRL_COMP_INT	0x4
> +#define ZYNQMP_DMA_DESC_CTRL_SIZE_256	0x2
> +#define ZYNQMP_DMA_DESC_CTRL_COHRNT	0x1
> +
> +/* Interrupt Mask specific definitions */
> +#define ZYNQMP_DMA_INT_ERR	(ZYNQMP_DMA_AXI_RD_DATA | \
> +				ZYNQMP_DMA_AXI_WR_DATA | \
> +				ZYNQMP_DMA_AXI_RD_DST_DSCR | \
> +				ZYNQMP_DMA_AXI_RD_SRC_DSCR | \
> +				ZYNQMP_DMA_INV_APB)
> +#define ZYNQMP_DMA_INT_OVRFL	(ZYNQMP_DMA_BYTE_CNT_OVRFL | \
> +				ZYNQMP_DMA_IRQ_SRC_ACCT_ERR | \
> +				ZYNQMP_DMA_IRQ_DST_ACCT_ERR)
> +#define ZYNQMP_DMA_INT_DONE	(ZYNQMP_DMA_DONE |
> ZYNQMP_DMA_DST_DSCR_DONE)
> +#define ZYNQMP_DMA_INT_EN_DEFAULT_MASK
> 	(ZYNQMP_DMA_INT_DONE | \
> +					ZYNQMP_DMA_INT_ERR | \
> +					ZYNQMP_DMA_INT_OVRFL | \
> +					ZYNQMP_DMA_DST_DSCR_DONE)
> +
> +/* Max number of descriptors per channel */
> +#define ZYNQMP_DMA_NUM_DESCS	32
> +
> +/* Max transfer size per descriptor */
> +#define ZYNQMP_DMA_MAX_TRANS_LEN	0x40000000
> +
> +/* Reset values for data attributes */
> +#define ZYNQMP_DMA_AXCACHE_VAL		0xF
> +#define ZYNQMP_DMA_ARLEN_RST_VAL	0xF
> +#define ZYNQMP_DMA_AWLEN_RST_VAL	0xF
> +
> +#define ZYNQMP_DMA_SRC_ISSUE_RST_VAL	0x1F
> +
> +#define ZYNQMP_DMA_IDS_DEFAULT_MASK	0xFFF
> +
> +/* Bus width in bits */
> +#define ZYNQMP_DMA_BUS_WIDTH_64		64
> +#define ZYNQMP_DMA_BUS_WIDTH_128	128
> +
> +#define ZYNQMP_DMA_DESC_SIZE(chan)	(chan->desc_size)
> +
> +#define to_chan(chan)		container_of(chan, struct zynqmp_dma_chan, \
> +					     common)
> +#define tx_to_desc(tx)		container_of(tx, struct zynqmp_dma_desc_sw,
> \
> +					     async_tx)
> +
> +/**
> + * struct zynqmp_dma_desc_ll - Hw linked list descriptor
> + * @addr: Buffer address
> + * @size: Size of the buffer
> + * @ctrl: Control word
> + * @nxtdscraddr: Next descriptor base address
> + * @rsvd: Reserved field and for Hw internal use.
> + */
> +struct zynqmp_dma_desc_ll {
> +	u64 addr;
> +	u32 size;
> +	u32 ctrl;
> +	u64 nxtdscraddr;
> +	u64 rsvd;
> +}; __aligned(64)
> +
> +/**
> + * struct zynqmp_dma_desc_sw - Per Transaction structure
> + * @src: Source address for simple mode dma
> + * @dst: Destination address for simple mode dma
> + * @len: Transfer length for simple mode dma
> + * @node: Node in the channel descriptor list
> + * @tx_list: List head for the current transfer
> + * @async_tx: Async transaction descriptor
> + * @src_v: Virtual address of the src descriptor
> + * @src_p: Physical address of the src descriptor
> + * @dst_v: Virtual address of the dst descriptor
> + * @dst_p: Physical address of the dst descriptor  */ struct
> +zynqmp_dma_desc_sw {
> +	u64 src;
> +	u64 dst;
> +	u32 len;
> +	struct list_head node;
> +	struct list_head tx_list;
> +	struct dma_async_tx_descriptor async_tx;
> +	struct zynqmp_dma_desc_ll *src_v;
> +	dma_addr_t src_p;
> +	struct zynqmp_dma_desc_ll *dst_v;
> +	dma_addr_t dst_p;
> +};
> +
> +/**
> + * struct zynqmp_dma_chan - Driver specific DMA channel structure
> + * @zdev: Driver specific device structure
> + * @regs: Control registers offset
> + * @lock: Descriptor operation lock
> + * @pending_list: Descriptors waiting
> + * @free_list: Descriptors free
> + * @active_list: Descriptors active
> + * @sw_desc_pool: SW descriptor pool
> + * @done_list: Complete descriptors
> + * @common: DMA common channel
> + * @desc_pool_v: Statically allocated descriptor base
> + * @desc_pool_p: Physical allocated descriptor base
> + * @desc_free_cnt: Descriptor available count
> + * @dev: The dma device
> + * @irq: Channel IRQ
> + * @is_dmacoherent: Tells whether dma operations are coherent or not
> + * @tasklet: Cleanup work after irq
> + * @idle : Channel status;
> + * @desc_size: Size of the low level descriptor
> + * @err: Channel has errors
> + * @bus_width: Bus width
> + * @clk_main: Pointer to main clock
> + * @clk_apb: Pointer to apb clock
> + * @config: Device configuration info
> + */
> +struct zynqmp_dma_chan {
> +	struct zynqmp_dma_device *zdev;
> +	void __iomem *regs;
> +	spinlock_t lock;
> +	struct list_head pending_list;
> +	struct list_head free_list;
> +	struct list_head active_list;
> +	struct zynqmp_dma_desc_sw *sw_desc_pool;
> +	struct list_head done_list;
> +	struct dma_chan common;
> +	void *desc_pool_v;
> +	dma_addr_t desc_pool_p;
> +	u32 desc_free_cnt;
> +	struct device *dev;
> +	int irq;
> +	bool is_dmacoherent;
> +	struct tasklet_struct tasklet;
> +	bool idle;
> +	u32 desc_size;
> +	bool err;
> +	u32 bus_width;
> +	struct clk *clk_main;
> +	struct clk *clk_apb;
> +	struct zynqmp_dma_config config;
> +};
> +
> +/**
> + * struct zynqmp_dma_device - DMA device structure
> + * @dev: Device Structure
> + * @common: DMA device structure
> + * @chan: Driver specific DMA channel
> + */
> +struct zynqmp_dma_device {
> +	struct device *dev;
> +	struct dma_device common;
> +	struct zynqmp_dma_chan *chan;
> +};
> +
> +/**
> + * zynqmp_dma_chan_is_idle - Provides the channel idle status
> + * @chan: ZynqMP DMA DMA channel pointer
> + *
> + * Return: 'true' if the channel is idle otherwise 'false'
> + */
> +static inline bool zynqmp_dma_chan_is_idle(struct zynqmp_dma_chan
> +*chan) {
> +	return chan->idle;
> +
> +}
> +
> +/**
> + * zynqmp_dma_update_desc_to_ctrlr - Updates descriptor to the
> +controller
> + * @chan: ZynqMP DMA DMA channel pointer
> + * @desc: Transaction descriptor pointer  */ static void
> +zynqmp_dma_update_desc_to_ctrlr(struct zynqmp_dma_chan *chan,
> +				      struct zynqmp_dma_desc_sw *desc) {
> +	dma_addr_t addr;
> +
> +	addr = desc->src_p;
> +	writel(addr, chan->regs + ZYNQMP_DMA_SRC_START_LSB);
> +	writel(upper_32_bits(addr), chan->regs +
> ZYNQMP_DMA_SRC_START_MSB);
> +	addr = desc->dst_p;
> +	writel(addr, chan->regs + ZYNQMP_DMA_DST_START_LSB);
> +	writel(upper_32_bits(addr), chan->regs +
> ZYNQMP_DMA_DST_START_MSB); }
> +
> +/**
> + * zynqmp_dma_desc_config_eod - Mark the descriptor as end descriptor
> + * @chan: ZynqMP DMA channel pointer
> + * @desc: Hw descriptor pointer
> + */
> +static void zynqmp_dma_desc_config_eod(struct zynqmp_dma_chan *chan,
> +void *desc) {
> +	struct zynqmp_dma_desc_ll *hw = (struct zynqmp_dma_desc_ll *)desc;
> +
> +	hw->ctrl |= ZYNQMP_DMA_DESC_CTRL_STOP;
> +	hw++;
> +	hw->ctrl |= ZYNQMP_DMA_DESC_CTRL_COMP_INT |
> ZYNQMP_DMA_DESC_CTRL_STOP;
> +}
> +
> +/**
> + * zynqmp_dma_config_simple_desc - Configure the transfer parameters
> + * @chan: ZynqMP DMA channel pointer
> + * @src: Source buffer address
> + * @dst: Destination buffer address
> + * @len: Transfer length
> + */
> +static void zynqmp_dma_config_simple_desc(struct zynqmp_dma_chan *chan,
> +					  dma_addr_t src, dma_addr_t dst,
> +					  size_t len)
> +{
> +	u32 val;
> +
> +	writel(src, chan->regs + ZYNQMP_DMA_SRC_DSCR_WRD0);
> +	writel(upper_32_bits(src), chan->regs +
> ZYNQMP_DMA_SRC_DSCR_WRD1);
> +	writel(len, chan->regs + ZYNQMP_DMA_SRC_DSCR_WRD2);
> +
> +	if (chan->is_dmacoherent)
> +		writel(ZYNQMP_DMA_DESC_CTRL_COHRNT,
> +			chan->regs + ZYNQMP_DMA_SRC_DSCR_WRD3);
> +	else
> +		writel(0, chan->regs + ZYNQMP_DMA_SRC_DSCR_WRD3);
> +
> +	writel(dst, chan->regs + ZYNQMP_DMA_DST_DSCR_WRD0);
> +	writel(upper_32_bits(dst), chan->regs +
> ZYNQMP_DMA_DST_DSCR_WRD1);
> +	writel(len, chan->regs + ZYNQMP_DMA_DST_DSCR_WRD2);
> +
> +	if (chan->is_dmacoherent)
> +		val = ZYNQMP_DMA_DESC_CTRL_COHRNT |
> +				ZYNQMP_DMA_DESC_CTRL_COMP_INT;
> +	else
> +		val = ZYNQMP_DMA_DESC_CTRL_COMP_INT;
> +	writel(val, chan->regs + ZYNQMP_DMA_DST_DSCR_WRD3); }
> +
> +/**
> + * zynqmp_dma_config_sg_ll_desc - Configure the linked list descriptor
> + * @chan: ZynqMP DMA channel pointer
> + * @sdesc: Hw descriptor pointer
> + * @src: Source buffer address
> + * @dst: Destination buffer address
> + * @len: Transfer length
> + * @prev: Previous hw descriptor pointer  */ static void
> +zynqmp_dma_config_sg_ll_desc(struct zynqmp_dma_chan *chan,
> +				   struct zynqmp_dma_desc_ll *sdesc,
> +				   dma_addr_t src, dma_addr_t dst, size_t len,
> +				   struct zynqmp_dma_desc_ll *prev) {
> +	struct zynqmp_dma_desc_ll *ddesc = sdesc + 1;
> +
> +	sdesc->size = ddesc->size = len;
> +	sdesc->addr = src;
> +	ddesc->addr = dst;
> +
> +	sdesc->ctrl = ddesc->ctrl = ZYNQMP_DMA_DESC_CTRL_SIZE_256;
> +	if (chan->is_dmacoherent) {
> +		sdesc->ctrl |= ZYNQMP_DMA_DESC_CTRL_COHRNT;
> +		ddesc->ctrl |= ZYNQMP_DMA_DESC_CTRL_COHRNT;
> +	}
> +
> +	if (prev) {
> +		dma_addr_t addr = chan->desc_pool_p +
> +			    ((dma_addr_t)sdesc - (dma_addr_t)chan-
> >desc_pool_v);
> +		ddesc = prev + 1;
> +		prev->nxtdscraddr = addr;
> +		ddesc->nxtdscraddr = addr + ZYNQMP_DMA_DESC_SIZE(chan);
> +	}
> +}
> +
> +/**
> + * zynqmp_dma_init - Initialize the channel
> + * @chan: ZynqMP DMA channel pointer
> + */
> +static void zynqmp_dma_init(struct zynqmp_dma_chan *chan) {
> +	u32 val;
> +
> +	writel(ZYNQMP_DMA_IDS_DEFAULT_MASK, chan->regs +
> ZYNQMP_DMA_IDS);
> +	val = readl(chan->regs + ZYNQMP_DMA_ISR);
> +	writel(val, chan->regs + ZYNQMP_DMA_ISR);
> +
> +	val = 0;
> +	if (chan->config.has_sg)
> +		val |= ZYNQMP_DMA_POINT_TYPE_SG;
> +	writel(val, chan->regs + ZYNQMP_DMA_CTRL0);
> +
> +	val = 0;
> +	if (chan->is_dmacoherent) {
> +		val |= ZYNQMP_DMA_AXCOHRNT;
> +		val = (val & ~ZYNQMP_DMA_AXCACHE) |
> +			(ZYNQMP_DMA_AXCACHE_VAL <<
> ZYNQMP_DMA_AXCACHE_OFST);
> +	}
> +	writel(val, chan->regs + ZYNQMP_DMA_DSCR_ATTR);
> +
> +	val = readl(chan->regs + ZYNQMP_DMA_DATA_ATTR);
> +	if (chan->is_dmacoherent) {
> +		val = (val & ~ZYNQMP_DMA_ARCACHE) |
> +			(ZYNQMP_DMA_AXCACHE_VAL <<
> ZYNQMP_DMA_ARCACHE_OFST);
> +		val = (val & ~ZYNQMP_DMA_AWCACHE) |
> +			(ZYNQMP_DMA_AXCACHE_VAL <<
> ZYNQMP_DMA_AWCACHE_OFST);
> +	}
> +	writel(val, chan->regs + ZYNQMP_DMA_DATA_ATTR);
> +
> +	/* Clearing the interrupt account rgisters */
> +	val = readl(chan->regs + ZYNQMP_DMA_IRQ_SRC_ACCT);
> +	val = readl(chan->regs + ZYNQMP_DMA_IRQ_DST_ACCT);
> +
> +	chan->idle = true;
> +}
> +
> +/**
> + * zynqmp_dma_tx_submit - Submit DMA transaction
> + * @tx: Async transaction descriptor pointer
> + *
> + * Return: cookie value
> + */
> +static dma_cookie_t zynqmp_dma_tx_submit(struct dma_async_tx_descriptor
> +*tx) {
> +	struct zynqmp_dma_chan *chan = to_chan(tx->chan);
> +	struct zynqmp_dma_desc_sw *desc, *new;
> +	dma_cookie_t cookie;
> +
> +	new = tx_to_desc(tx);
> +	spin_lock_bh(&chan->lock);
> +	cookie = dma_cookie_assign(tx);
> +
> +	if (!list_empty(&chan->pending_list) && chan->config.has_sg) {
> +		desc = list_last_entry(&chan->pending_list,
> +				     struct zynqmp_dma_desc_sw, node);
> +		if (!list_empty(&desc->tx_list))
> +			desc = list_last_entry(&desc->tx_list,
> +					       struct zynqmp_dma_desc_sw,
> node);
> +		desc->src_v->nxtdscraddr = new->src_p;
> +		desc->src_v->ctrl &= ~ZYNQMP_DMA_DESC_CTRL_STOP;
> +		desc->dst_v->nxtdscraddr = new->dst_p;
> +		desc->dst_v->ctrl &= ~ZYNQMP_DMA_DESC_CTRL_STOP;
> +	}
> +
> +	list_add_tail(&new->node, &chan->pending_list);
> +	spin_unlock_bh(&chan->lock);
> +
> +	return cookie;
> +}
> +
> +/**
> + * zynqmp_dma_get_descriptor - Get the sw descriptor from the pool
> + * @chan: ZynqMP DMA channel pointer
> + *
> + * Return: The sw descriptor
> + */
> +static struct zynqmp_dma_desc_sw *
> +zynqmp_dma_get_descriptor(struct zynqmp_dma_chan *chan) {
> +	struct zynqmp_dma_desc_sw *desc;
> +
> +	spin_lock_bh(&chan->lock);
> +	desc = list_first_entry(&chan->free_list, struct zynqmp_dma_desc_sw,
> +				 node);
> +	list_del(&desc->node);
> +	spin_unlock_bh(&chan->lock);
> +
> +	INIT_LIST_HEAD(&desc->tx_list);
> +	/* Clear the src and dst descriptor memory */
> +	if (chan->config.has_sg) {
> +		memset((void *)desc->src_v, 0,
> ZYNQMP_DMA_DESC_SIZE(chan));
> +		memset((void *)desc->dst_v, 0,
> ZYNQMP_DMA_DESC_SIZE(chan));
> +	}
> +
> +	return desc;
> +}
> +
> +/**
> + * zynqmp_dma_free_descriptor - Issue pending transactions
> + * @chan: ZynqMP DMA channel pointer
> + * @sdesc: Transaction descriptor pointer  */ static void
> +zynqmp_dma_free_descriptor(struct zynqmp_dma_chan *chan,
> +				 struct zynqmp_dma_desc_sw *sdesc)
> +{
> +	struct zynqmp_dma_desc_sw *child, *next;
> +
> +	chan->desc_free_cnt++;
> +	list_add_tail(&sdesc->node, &chan->free_list);
> +	list_for_each_entry_safe(child, next, &sdesc->tx_list, node) {
> +		chan->desc_free_cnt++;
> +		INIT_LIST_HEAD(&child->tx_list);
> +		list_move_tail(&child->node, &chan->free_list);
> +	}
> +	INIT_LIST_HEAD(&sdesc->tx_list);
> +}
> +
> +/**
> + * zynqmp_dma_free_desc_list - Free descriptors list
> + * @chan: ZynqMP DMA channel pointer
> + * @list: List to parse and delete the descriptor  */ static void
> +zynqmp_dma_free_desc_list(struct zynqmp_dma_chan *chan,
> +				      struct list_head *list)
> +{
> +	struct zynqmp_dma_desc_sw *desc, *next;
> +
> +	list_for_each_entry_safe(desc, next, list, node)
> +		zynqmp_dma_free_descriptor(chan, desc); }
> +
> +/**
> + * zynqmp_dma_alloc_chan_resources - Allocate channel resources
> + * @dchan: DMA channel
> + *
> + * Return: Number of descriptors on success and failure value on error
> +*/ static int zynqmp_dma_alloc_chan_resources(struct dma_chan *dchan) {
> +	struct zynqmp_dma_chan *chan = to_chan(dchan);
> +	struct zynqmp_dma_desc_sw *desc;
> +	int i;
> +
> +	chan->sw_desc_pool = kzalloc(sizeof(*desc) *
> ZYNQMP_DMA_NUM_DESCS,
> +				     GFP_KERNEL);
> +	if (!chan->sw_desc_pool)
> +		return -ENOMEM;
> +	chan->idle = true;
> +	chan->desc_free_cnt = ZYNQMP_DMA_NUM_DESCS;
> +
> +	INIT_LIST_HEAD(&chan->free_list);
> +
> +	for (i = 0; i < ZYNQMP_DMA_NUM_DESCS; i++) {
> +		desc = chan->sw_desc_pool + i;
> +		dma_async_tx_descriptor_init(&desc->async_tx, &chan-
> >common);
> +		desc->async_tx.tx_submit = zynqmp_dma_tx_submit;
> +		list_add_tail(&desc->node, &chan->free_list);
> +	}
> +
> +	chan->desc_pool_v = dma_zalloc_coherent(chan->dev,
> +				(2 * chan->desc_size *
> ZYNQMP_DMA_NUM_DESCS),
> +				&chan->desc_pool_p, GFP_KERNEL);
> +	if (!chan->desc_pool_v)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < ZYNQMP_DMA_NUM_DESCS; i++) {
> +		desc = chan->sw_desc_pool + i;
> +		desc->src_v = (struct zynqmp_dma_desc_ll *) (chan-
> >desc_pool_v +
> +					(i * ZYNQMP_DMA_DESC_SIZE(chan) *
> 2));
> +		desc->dst_v = (struct zynqmp_dma_desc_ll *) (desc->src_v + 1);
> +		desc->src_p = chan->desc_pool_p +
> +				(i * ZYNQMP_DMA_DESC_SIZE(chan) * 2);
> +		desc->dst_p = desc->src_p + ZYNQMP_DMA_DESC_SIZE(chan);
> +	}
> +
> +	return ZYNQMP_DMA_NUM_DESCS;
> +}
> +
> +/**
> + * zynqmp_dma_start - Start DMA channel
> + * @chan: ZynqMP DMA channel pointer
> + */
> +static void zynqmp_dma_start(struct zynqmp_dma_chan *chan) {
> +	writel(ZYNQMP_DMA_INT_EN_DEFAULT_MASK, chan->regs +
> ZYNQMP_DMA_IER);
> +	chan->idle = false;
> +	writel(ZYNQMP_DMA_ENABLE, chan->regs + ZYNQMP_DMA_CTRL2); }
> +
> +/**
> + * zynqmp_dma_handle_ovfl_int - Process the overflow interrupt
> + * @chan: ZynqMP DMA channel pointer
> + * @status: Interrupt status value
> + */
> +static void zynqmp_dma_handle_ovfl_int(struct zynqmp_dma_chan *chan,
> +u32 status) {
> +	u32 val;
> +
> +	if (status & ZYNQMP_DMA_IRQ_DST_ACCT_ERR)
> +		val = readl(chan->regs + ZYNQMP_DMA_IRQ_DST_ACCT);
> +	if (status & ZYNQMP_DMA_IRQ_SRC_ACCT_ERR)
> +		val = readl(chan->regs + ZYNQMP_DMA_IRQ_SRC_ACCT); }
> +
> +static void zynqmp_dma_config(struct zynqmp_dma_chan *chan) {
> +	u32 val;
> +
> +	val = readl(chan->regs + ZYNQMP_DMA_CTRL0);
> +	if (chan->config.ovrfetch)
> +		val |= ZYNQMP_DMA_OVR_FETCH;
> +	if (chan->config.ratectrl) {
> +		val |= ZYNQMP_DMA_RATE_CTRL_EN;
> +		writel(chan->config.ratectrl, chan->regs +
> +		       ZYNQMP_DMA_RATE_CTRL);
> +	}
> +	writel(val, chan->regs + ZYNQMP_DMA_CTRL0);
> +
> +	val = readl(chan->regs + ZYNQMP_DMA_CTRL1);
> +	if (chan->config.src_issue)
> +		val = (val & ~ZYNQMP_DMA_SRC_ISSUE) | chan-
> >config.src_issue;
> +	else
> +		val |= ZYNQMP_DMA_SRC_ISSUE_RST_VAL;
> +	writel(val, chan->regs + ZYNQMP_DMA_CTRL1);
> +
> +	val = readl(chan->regs + ZYNQMP_DMA_DATA_ATTR);
> +	if (chan->config.src_burst_len)
> +		val = (val & ~ZYNQMP_DMA_ARLEN) |
> +			(chan->config.src_burst_len <<
> ZYNQMP_DMA_ARLEN_OFST);
> +	else
> +		val |= ZYNQMP_DMA_ARLEN_RST_VAL;
> +
> +	if (chan->config.dst_burst_len)
> +		val = (val & ~ZYNQMP_DMA_AWLEN) |
> +			(chan->config.dst_burst_len <<
> ZYNQMP_DMA_AWLEN_OFST);
> +	else
> +		val |= ZYNQMP_DMA_AWLEN_RST_VAL;
> +	writel(val, chan->regs + ZYNQMP_DMA_DATA_ATTR);
> +
> +}
> +
> +/**
> + * zynqmp_dma_start_transfer - Initiate the new transfer
> + * @chan: ZynqMP DMA channel pointer
> + */
> +static void zynqmp_dma_start_transfer(struct zynqmp_dma_chan *chan) {
> +	struct zynqmp_dma_desc_sw *desc;
> +
> +	if (!zynqmp_dma_chan_is_idle(chan))
> +		return;
> +
> +	zynqmp_dma_config(chan);
> +
> +	desc = list_first_entry_or_null(&chan->pending_list,
> +					struct zynqmp_dma_desc_sw, node);
> +	if (!desc)
> +		return;
> +
> +	if (chan->config.has_sg)
> +		list_splice_tail_init(&chan->pending_list, &chan->active_list);
> +	else
> +		list_move_tail(&desc->node, &chan->active_list);
> +
> +	if (chan->config.has_sg)
> +		zynqmp_dma_update_desc_to_ctrlr(chan, desc);
> +	else
> +		zynqmp_dma_config_simple_desc(chan, desc->src, desc->dst,
> +					      desc->len);
> +
> +	zynqmp_dma_start(chan);
> +}
> +
> +
> +/**
> + * zynqmp_dma_chan_desc_cleanup - Cleanup the completed descriptors
> + * @chan: ZynqMP DMA channel
> + */
> +static void zynqmp_dma_chan_desc_cleanup(struct zynqmp_dma_chan *chan)
> +{
> +	struct zynqmp_dma_desc_sw *desc, *next;
> +
> +	list_for_each_entry_safe(desc, next, &chan->done_list, node) {
> +		dma_async_tx_callback callback;
> +		void *callback_param;
> +
> +		list_del(&desc->node);
> +
> +		callback = desc->async_tx.callback;
> +		callback_param = desc->async_tx.callback_param;
> +		if (callback) {
> +			spin_unlock(&chan->lock);
> +			callback(callback_param);
> +			spin_lock(&chan->lock);
> +		}
> +
> +		/* Run any dependencies, then free the descriptor */
> +		zynqmp_dma_free_descriptor(chan, desc);
> +	}
> +}
> +
> +/**
> + * zynqmp_dma_complete_descriptor - Mark the active descriptor as
> +complete
> + * @chan: ZynqMP DMA channel pointer
> + */
> +static void zynqmp_dma_complete_descriptor(struct zynqmp_dma_chan
> +*chan) {
> +	struct zynqmp_dma_desc_sw *desc;
> +
> +	desc = list_first_entry_or_null(&chan->active_list,
> +					struct zynqmp_dma_desc_sw, node);
> +	if (!desc)
> +		return;
> +	list_del(&desc->node);
> +	dma_cookie_complete(&desc->async_tx);
> +	list_add_tail(&desc->node, &chan->done_list); }
> +
> +/**
> + * zynqmp_dma_issue_pending - Issue pending transactions
> + * @dchan: DMA channel pointer
> + */
> +static void zynqmp_dma_issue_pending(struct dma_chan *dchan) {
> +	struct zynqmp_dma_chan *chan = to_chan(dchan);
> +
> +	spin_lock_bh(&chan->lock);
> +	zynqmp_dma_start_transfer(chan);
> +	spin_unlock_bh(&chan->lock);
> +}
> +
> +/**
> + * zynqmp_dma_free_descriptors - Free channel descriptors
> + * @dchan: DMA channel pointer
> + */
> +static void zynqmp_dma_free_descriptors(struct zynqmp_dma_chan *chan) {
> +	zynqmp_dma_free_desc_list(chan, &chan->active_list);
> +	zynqmp_dma_free_desc_list(chan, &chan->pending_list);
> +	zynqmp_dma_free_desc_list(chan, &chan->done_list); }
> +
> +/**
> + * zynqmp_dma_free_chan_resources - Free channel resources
> + * @dchan: DMA channel pointer
> + */
> +static void zynqmp_dma_free_chan_resources(struct dma_chan *dchan) {
> +	struct zynqmp_dma_chan *chan = to_chan(dchan);
> +
> +	spin_lock_bh(&chan->lock);
> +	zynqmp_dma_free_descriptors(chan);
> +	spin_unlock_bh(&chan->lock);
> +	dma_free_coherent(chan->dev,
> +		(2 * ZYNQMP_DMA_DESC_SIZE(chan) *
> ZYNQMP_DMA_NUM_DESCS),
> +		chan->desc_pool_v, chan->desc_pool_p);
> +	kfree(chan->sw_desc_pool);
> +}
> +
> +/**
> + * zynqmp_dma_tx_status - Get dma transaction status
> + * @dchan: DMA channel pointer
> + * @cookie: Transaction identifier
> + * @txstate: Transaction state
> + *
> + * Return: DMA transaction status
> + */
> +static enum dma_status zynqmp_dma_tx_status(struct dma_chan *dchan,
> +				      dma_cookie_t cookie,
> +				      struct dma_tx_state *txstate) {
> +	return dma_cookie_status(dchan, cookie, txstate); }
> +
> +/**
> + * zynqmp_dma_reset - Reset the channel
> + * @chan: ZynqMP DMA channel pointer
> + */
> +static void zynqmp_dma_reset(struct zynqmp_dma_chan *chan) {
> +	writel(ZYNQMP_DMA_IDS_DEFAULT_MASK, chan->regs +
> ZYNQMP_DMA_IDS);
> +
> +	zynqmp_dma_complete_descriptor(chan);
> +	zynqmp_dma_chan_desc_cleanup(chan);
> +	zynqmp_dma_free_descriptors(chan);
> +	zynqmp_dma_init(chan);
> +}
> +
> +/**
> + * zynqmp_dma_irq_handler - ZynqMP DMA Interrupt handler
> + * @irq: IRQ number
> + * @data: Pointer to the ZynqMP DMA channel structure
> + *
> + * Return: IRQ_HANDLED/IRQ_NONE
> + */
> +static irqreturn_t zynqmp_dma_irq_handler(int irq, void *data) {
> +	struct zynqmp_dma_chan *chan = (struct zynqmp_dma_chan *)data;
> +	u32 isr, imr, status;
> +	irqreturn_t ret = IRQ_NONE;
> +
> +	isr = readl(chan->regs + ZYNQMP_DMA_ISR);
> +	imr = readl(chan->regs + ZYNQMP_DMA_IMR);
> +	status = isr & ~imr;
> +
> +	writel(isr, chan->regs + ZYNQMP_DMA_ISR);
> +	if (status & ZYNQMP_DMA_INT_DONE) {
> +		tasklet_schedule(&chan->tasklet);
> +		ret = IRQ_HANDLED;
> +	}
> +
> +	if (status & ZYNQMP_DMA_DONE)
> +		chan->idle = true;
> +
> +	if (status & ZYNQMP_DMA_INT_ERR) {
> +		chan->err = true;
> +		tasklet_schedule(&chan->tasklet);
> +		dev_err(chan->dev, "Channel %p has errors\n", chan);
> +		ret = IRQ_HANDLED;
> +	}
> +
> +	if (status & ZYNQMP_DMA_INT_OVRFL) {
> +		zynqmp_dma_handle_ovfl_int(chan, status);
> +		dev_info(chan->dev, "Channel %p overflow interrupt\n", chan);
> +		ret = IRQ_HANDLED;
> +	}
> +
> +	return ret;
> +}
> +
> +/**
> + * zynqmp_dma_do_tasklet - Schedule completion tasklet
> + * @data: Pointer to the ZynqMP DMA channel structure  */ static void
> +zynqmp_dma_do_tasklet(unsigned long data) {
> +	struct zynqmp_dma_chan *chan = (struct zynqmp_dma_chan *)data;
> +	u32 count;
> +
> +	spin_lock(&chan->lock);
> +
> +	if (chan->err) {
> +		zynqmp_dma_reset(chan);
> +		chan->err = false;
> +		goto unlock;
> +	}
> +
> +	count = readl(chan->regs + ZYNQMP_DMA_IRQ_DST_ACCT);
> +
> +	while (count) {
> +		zynqmp_dma_complete_descriptor(chan);
> +		zynqmp_dma_chan_desc_cleanup(chan);
> +		count--;
> +	}
> +
> +	if (chan->idle)
> +		zynqmp_dma_start_transfer(chan);
> +
> +unlock:
> +	spin_unlock(&chan->lock);
> +}
> +
> +/**
> + * zynqmp_dma_device_terminate_all - Aborts all transfers on a channel
> + * @dchan: DMA channel pointer
> + *
> + * Return: Always '0'
> + */
> +static int zynqmp_dma_device_terminate_all(struct dma_chan *dchan) {
> +	struct zynqmp_dma_chan *chan = to_chan(dchan);
> +
> +	spin_lock_bh(&chan->lock);
> +	writel(ZYNQMP_DMA_IDS_DEFAULT_MASK, chan->regs +
> ZYNQMP_DMA_IDS);
> +	zynqmp_dma_free_descriptors(chan);
> +	spin_unlock_bh(&chan->lock);
> +
> +	return 0;
> +}
> +
> +/**
> + * zynqmp_dma_prep_memcpy - prepare descriptors for memcpy transaction
> + * @dchan: DMA channel
> + * @dma_dst: Destination buffer address
> + * @dma_src: Source buffer address
> + * @len: Transfer length
> + * @flags: transfer ack flags
> + *
> + * Return: Async transaction descriptor on success and NULL on failure
> +*/ static struct dma_async_tx_descriptor *zynqmp_dma_prep_memcpy(
> +				struct dma_chan *dchan, dma_addr_t
> dma_dst,
> +				dma_addr_t dma_src, size_t len, ulong flags) {
> +	struct zynqmp_dma_chan *chan;
> +	struct zynqmp_dma_desc_sw *new, *first = NULL;
> +	void *desc = NULL, *prev = NULL;
> +	size_t copy;
> +	u32 desc_cnt;
> +
> +	chan = to_chan(dchan);
> +
> +	if ((len > ZYNQMP_DMA_MAX_TRANS_LEN) && !chan->config.has_sg)
> +		return NULL;
> +
> +	desc_cnt = DIV_ROUND_UP(len, ZYNQMP_DMA_MAX_TRANS_LEN);
> +
> +	spin_lock_bh(&chan->lock);
> +	if ((desc_cnt > chan->desc_free_cnt) && chan->config.has_sg) {
> +		spin_unlock_bh(&chan->lock);
> +		dev_dbg(chan->dev, "chan %p descs are not available\n", chan);
> +		return NULL;
> +	}
> +	chan->desc_free_cnt = chan->desc_free_cnt - desc_cnt;
> +	spin_unlock_bh(&chan->lock);
> +
> +	do {
> +		/* Allocate and populate the descriptor */
> +		new = zynqmp_dma_get_descriptor(chan);
> +
> +		copy = min_t(size_t, len, ZYNQMP_DMA_MAX_TRANS_LEN);
> +		if (chan->config.has_sg) {
> +			desc = (struct zynqmp_dma_desc_ll *)new->src_v;
> +			zynqmp_dma_config_sg_ll_desc(chan, desc, dma_src,
> +						     dma_dst, copy, prev);
> +		} else {
> +			new->src = dma_src;
> +			new->dst = dma_dst;
> +			new->len = len;
> +		}
> +
> +		prev = desc;
> +		len -= copy;
> +		dma_src += copy;
> +		dma_dst += copy;
> +		if (!first)
> +			first = new;
> +		else
> +			list_add_tail(&new->node, &first->tx_list);
> +	} while (len);
> +
> +	if (chan->config.has_sg)
> +		zynqmp_dma_desc_config_eod(chan, desc);
> +
> +	async_tx_ack(&first->async_tx);
> +	first->async_tx.flags = flags;
> +	return &first->async_tx;
> +}
> +
> +/**
> + * zynqmp_dma_prep_slave_sg - prepare descriptors for a memory sg
> +transaction
> + * @dchan: DMA channel
> + * @dst_sg: Destination scatter list
> + * @dst_sg_len: Number of entries in destination scatter list
> + * @src_sg: Source scatter list
> + * @src_sg_len: Number of entries in source scatter list
> + * @flags: transfer ack flags
> + *
> + * Return: Async transaction descriptor on success and NULL on failure
> +*/ static struct dma_async_tx_descriptor *zynqmp_dma_prep_sg(
> +			struct dma_chan *dchan, struct scatterlist *dst_sg,
> +			unsigned int dst_sg_len, struct scatterlist *src_sg,
> +			unsigned int src_sg_len, unsigned long flags) {
> +	struct zynqmp_dma_desc_sw *new, *first = NULL;
> +	struct zynqmp_dma_chan *chan = to_chan(dchan);
> +	void *desc = NULL, *prev = NULL;
> +	size_t len, dst_avail, src_avail;
> +	dma_addr_t dma_dst, dma_src;
> +	u32 desc_cnt = 0, i;
> +	struct scatterlist *sg;
> +
> +	if (!chan->config.has_sg)
> +		return NULL;
> +
> +	for_each_sg(src_sg, sg, src_sg_len, i)
> +		desc_cnt += DIV_ROUND_UP(sg_dma_len(sg),
> +					 ZYNQMP_DMA_MAX_TRANS_LEN);
> +
> +	spin_lock_bh(&chan->lock);
> +	if (desc_cnt > chan->desc_free_cnt) {
> +		spin_unlock_bh(&chan->lock);
> +		dev_dbg(chan->dev, "chan %p descs are not available\n", chan);
> +		return NULL;
> +	}
> +	chan->desc_free_cnt = chan->desc_free_cnt - desc_cnt;
> +	spin_unlock_bh(&chan->lock);
> +
> +	dst_avail = sg_dma_len(dst_sg);
> +	src_avail = sg_dma_len(src_sg);
> +
> +	/* Run until we are out of scatterlist entries */
> +	while (true) {
> +		/* Allocate and populate the descriptor */
> +		new = zynqmp_dma_get_descriptor(chan);
> +		desc = (struct zynqmp_dma_desc_ll *)new->src_v;
> +		len = min_t(size_t, src_avail, dst_avail);
> +		len = min_t(size_t, len, ZYNQMP_DMA_MAX_TRANS_LEN);
> +		if (len == 0)
> +			goto fetch;
> +		dma_dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) -
> +			dst_avail;
> +		dma_src = sg_dma_address(src_sg) + sg_dma_len(src_sg) -
> +			src_avail;
> +
> +		zynqmp_dma_config_sg_ll_desc(chan, desc, dma_src, dma_dst,
> +					     len, prev);
> +		prev = desc;
> +		dst_avail -= len;
> +		src_avail -= len;
> +
> +		if (!first)
> +			first = new;
> +		else
> +			list_add_tail(&new->node, &first->tx_list);
> +fetch:
> +		/* Fetch the next dst scatterlist entry */
> +		if (dst_avail == 0) {
> +			if (dst_sg_len == 0)
> +				break;
> +			dst_sg = sg_next(dst_sg);
> +			if (dst_sg == NULL)
> +				break;
> +			dst_sg_len--;
> +			dst_avail = sg_dma_len(dst_sg);
> +		}
> +		/* Fetch the next src scatterlist entry */
> +		if (src_avail == 0) {
> +			if (src_sg_len == 0)
> +				break;
> +			src_sg = sg_next(src_sg);
> +			if (src_sg == NULL)
> +				break;
> +			src_sg_len--;
> +			src_avail = sg_dma_len(src_sg);
> +		}
> +	}
> +
> +	zynqmp_dma_desc_config_eod(chan, desc);
> +	first->async_tx.flags = flags;
> +	return &first->async_tx;
> +}
> +
> +/**
> + * zynqmp_dma_channel_set_config - Configure ZYNQMP DMA channel
> + * @dchan: DMA channel
> + * @cfg: ZYNQMP DMA device configuration pointer
> + *
> + * Return: '0' always
> + */
> +int zynqmp_dma_channel_set_config(struct dma_chan *dchan,
> +				  struct zynqmp_dma_config *cfg)
> +{
> +	struct zynqmp_dma_chan *chan = to_chan(dchan);
> +
> +	chan->config.ovrfetch = cfg->ovrfetch;
> +	chan->config.has_sg = cfg->has_sg;
> +	chan->config.ratectrl = cfg->ratectrl;
> +	chan->config.src_issue = cfg->src_issue;
> +	chan->config.src_burst_len = cfg->src_burst_len;
> +	chan->config.dst_burst_len = cfg->dst_burst_len;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(zynqmp_dma_channel_set_config);
> +
> +/**
> + * zynqmp_dma_chan_remove - Channel remove function
> + * @chan: ZynqMP DMA channel pointer
> + */
> +static void zynqmp_dma_chan_remove(struct zynqmp_dma_chan *chan) {
> +	if (!chan)
> +		return;
> +
> +	devm_free_irq(chan->zdev->dev, chan->irq, chan);
> +	tasklet_kill(&chan->tasklet);
> +	list_del(&chan->common.device_node);
> +	clk_disable_unprepare(chan->clk_apb);
> +	clk_disable_unprepare(chan->clk_main);
> +}
> +
> +/**
> + * zynqmp_dma_chan_probe - Per Channel Probing
> + * @zdev: Driver specific device structure
> + * @pdev: Pointer to the platform_device structure
> + *
> + * Return: '0' on success and failure value on error  */ static int
> +zynqmp_dma_chan_probe(struct zynqmp_dma_device *zdev,
> +			   struct platform_device *pdev)
> +{
> +	struct zynqmp_dma_chan *chan;
> +	struct resource *res;
> +	struct device_node *node = pdev->dev.of_node;
> +	int err;
> +
> +	chan = devm_kzalloc(zdev->dev, sizeof(*chan), GFP_KERNEL);
> +	if (!chan)
> +		return -ENOMEM;
> +	chan->dev = zdev->dev;
> +	chan->zdev = zdev;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	chan->regs = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(chan->regs))
> +		return PTR_ERR(chan->regs);
> +
> +	chan->bus_width = ZYNQMP_DMA_BUS_WIDTH_64;
> +	chan->config.src_issue = ZYNQMP_DMA_SRC_ISSUE_RST_VAL;
> +	chan->config.dst_burst_len = ZYNQMP_DMA_AWLEN_RST_VAL;
> +	chan->config.src_burst_len = ZYNQMP_DMA_ARLEN_RST_VAL;
> +	err = of_property_read_u32(node, "xlnx,bus-width", &chan-
> >bus_width);
> +	if ((err < 0) && ((chan->bus_width != ZYNQMP_DMA_BUS_WIDTH_64) ||
> +			  (chan->bus_width !=
> ZYNQMP_DMA_BUS_WIDTH_128))) {
> +		dev_err(zdev->dev, "invalid bus-width value");
> +		return err;
> +	}
> +
> +	chan->bus_width = chan->bus_width / 8;
> +	chan->is_dmacoherent =  of_property_read_bool(node, "dma-
> coherent");
> +
> +	zdev->chan = chan;
> +	tasklet_init(&chan->tasklet, zynqmp_dma_do_tasklet, (ulong)chan);
> +	spin_lock_init(&chan->lock);
> +	INIT_LIST_HEAD(&chan->active_list);
> +	INIT_LIST_HEAD(&chan->pending_list);
> +	INIT_LIST_HEAD(&chan->done_list);
> +	INIT_LIST_HEAD(&chan->free_list);
> +
> +	dma_cookie_init(&chan->common);
> +	chan->common.device = &zdev->common;
> +	list_add_tail(&chan->common.device_node, &zdev-
> >common.channels);
> +
> +	zynqmp_dma_init(chan);
> +	chan->irq = platform_get_irq(pdev, 0);
> +	if (chan->irq < 0)
> +		return -ENXIO;
> +	err = devm_request_irq(&pdev->dev, chan->irq,
> zynqmp_dma_irq_handler, 0,
> +			       "zynqmp-dma", chan);
> +	if (err)
> +		return err;
> +	chan->clk_main = devm_clk_get(&pdev->dev, "clk_main");
> +	if (IS_ERR(chan->clk_main)) {
> +		dev_err(&pdev->dev, "main clock not found.\n");
> +		return PTR_ERR(chan->clk_main);
> +	}
> +
> +	chan->clk_apb = devm_clk_get(&pdev->dev, "clk_apb");
> +	if (IS_ERR(chan->clk_apb)) {
> +		dev_err(&pdev->dev, "apb clock not found.\n");
> +		return PTR_ERR(chan->clk_apb);
> +	}
> +
> +	err = clk_prepare_enable(chan->clk_main);
> +	if (err) {
> +		dev_err(&pdev->dev, "Unable to enable main clock.\n");
> +		return err;
> +	}
> +
> +	err = clk_prepare_enable(chan->clk_apb);
> +	if (err) {
> +		clk_disable_unprepare(chan->clk_main);
> +		dev_err(&pdev->dev, "Unable to enable apb clock.\n");
> +		return err;
> +	}
> +
> +	chan->desc_size = sizeof(struct zynqmp_dma_desc_ll);
> +	chan->idle = true;
> +	return 0;
> +}
> +
> +/**
> + * of_zynqmp_dma_xlate - Translation function
> + * @dma_spec: Pointer to DMA specifier as found in the device tree
> + * @ofdma: Pointer to DMA controller data
> + *
> + * Return: DMA channel pointer on success and NULL on error  */ static
> +struct dma_chan *of_zynqmp_dma_xlate(struct of_phandle_args *dma_spec,
> +					    struct of_dma *ofdma)
> +{
> +	struct zynqmp_dma_device *zdev = ofdma->of_dma_data;
> +
> +	return dma_get_slave_channel(&zdev->chan->common);
> +}
> +
> +/**
> + * zynqmp_dma_probe - Driver probe function
> + * @pdev: Pointer to the platform_device structure
> + *
> + * Return: '0' on success and failure value on error  */ static int
> +zynqmp_dma_probe(struct platform_device *pdev) {
> +	struct zynqmp_dma_device *zdev;
> +	struct dma_device *p;
> +	int ret;
> +
> +	zdev = devm_kzalloc(&pdev->dev, sizeof(*zdev), GFP_KERNEL);
> +	if (!zdev)
> +		return -ENOMEM;
> +
> +	zdev->dev = &pdev->dev;
> +	INIT_LIST_HEAD(&zdev->common.channels);
> +
> +	dma_set_mask(&pdev->dev, DMA_BIT_MASK(44));
> +	dma_cap_set(DMA_SG, zdev->common.cap_mask);
> +	dma_cap_set(DMA_MEMCPY, zdev->common.cap_mask);
> +
> +	p = &zdev->common;
> +	p->device_prep_dma_sg = zynqmp_dma_prep_sg;
> +	p->device_prep_dma_memcpy = zynqmp_dma_prep_memcpy;
> +	p->device_terminate_all = zynqmp_dma_device_terminate_all;
> +	p->device_issue_pending = zynqmp_dma_issue_pending;
> +	p->device_alloc_chan_resources = zynqmp_dma_alloc_chan_resources;
> +	p->device_free_chan_resources = zynqmp_dma_free_chan_resources;
> +	p->device_tx_status = zynqmp_dma_tx_status;
> +	p->dev = &pdev->dev;
> +
> +	platform_set_drvdata(pdev, zdev);
> +
> +	ret = zynqmp_dma_chan_probe(zdev, pdev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Probing channel failed\n");
> +		goto free_chan_resources;
> +	}
> +
> +	p->dst_addr_widths = BIT(zdev->chan->bus_width);
> +	p->src_addr_widths = BIT(zdev->chan->bus_width);
> +
> +	dma_async_device_register(&zdev->common);
> +
> +	ret = of_dma_controller_register(pdev->dev.of_node,
> +					 of_zynqmp_dma_xlate, zdev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Unable to register DMA to DT\n");
> +		dma_async_device_unregister(&zdev->common);
> +		goto free_chan_resources;
> +	}
> +
> +	dev_info(&pdev->dev, "ZynqMP DMA driver Probe success\n");
> +
> +	return 0;
> +
> +free_chan_resources:
> +	zynqmp_dma_chan_remove(zdev->chan);
> +	return ret;
> +}
> +
> +/**
> + * zynqmp_dma_remove - Driver remove function
> + * @pdev: Pointer to the platform_device structure
> + *
> + * Return: Always '0'
> + */
> +static int zynqmp_dma_remove(struct platform_device *pdev) {
> +	struct zynqmp_dma_device *zdev = platform_get_drvdata(pdev);
> +
> +	of_dma_controller_free(pdev->dev.of_node);
> +	dma_async_device_unregister(&zdev->common);
> +
> +	zynqmp_dma_chan_remove(zdev->chan);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id zynqmp_dma_of_match[] = {
> +	{ .compatible = "xlnx,zynqmp-dma-1.0", },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, zynqmp_dma_of_match);
> +
> +static struct platform_driver zynqmp_dma_driver = {
> +	.driver = {
> +		.name = "xilinx-zynqmp-dma",
> +		.of_match_table = zynqmp_dma_of_match,
> +	},
> +	.probe = zynqmp_dma_probe,
> +	.remove = zynqmp_dma_remove,
> +};
> +
> +module_platform_driver(zynqmp_dma_driver);
> +
> +MODULE_AUTHOR("Xilinx, Inc.");
> +MODULE_DESCRIPTION("Xilinx ZynqMP DMA driver");
> MODULE_LICENSE("GPL");
> diff --git a/include/linux/dma/xilinx_dma.h b/include/linux/dma/xilinx_dma.h
> index 3ae3000..7d7312f 100644
> --- a/include/linux/dma/xilinx_dma.h
> +++ b/include/linux/dma/xilinx_dma.h
> @@ -42,6 +42,24 @@ struct xilinx_vdma_config {  };
> 
>  /**
> + * struct zynqmp_dma_config - ZYNQMP DMA Configuration structure
> + * @ovrfetch: Overfetch status
> + * @has_sg: Support scatter gather transfers
> + * @ratectrl: Rate control value
> + * @src_issue: Out standing transactions on source
> + * @src_burst_len: Source burst length
> + * @dst_burst_len: Dest burst length
> + */
> +struct zynqmp_dma_config {
> +	bool ovrfetch;
> +	bool has_sg;
> +	u32 ratectrl;
> +	u32 src_issue;
> +	u32 src_burst_len;
> +	u32 dst_burst_len;
> +};
> +
> +/**
>   * enum xdma_ip_type: DMA IP type.
>   *
>   * XDMA_TYPE_AXIDMA: Axi dma ip.
> @@ -57,5 +75,6 @@ enum xdma_ip_type {
> 
>  int xilinx_vdma_channel_set_config(struct dma_chan *dchan,
>  					struct xilinx_vdma_config *cfg);
> -
> +int zynqmp_dma_channel_set_config(struct dma_chan *dchan,
> +					struct zynqmp_dma_config *cfg);
>  #endif
> --
> 2.1.1




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