--- /dev/null
+/*
+ * DMA driver for Xilinx Video DMA Engine
+ *
+ * Copyright (C) 2010-2014 Xilinx, Inc. All rights reserved.
+ *
+ * Based on the Freescale DMA driver.
+ *
+ * Description:
+ * The AXI Video Direct Memory Access (AXI VDMA) core is a soft Xilinx IP
+ * core that provides high-bandwidth direct memory access between memory
+ * and AXI4-Stream type video target peripherals. The core provides efficient
+ * two dimensional DMA operations with independent asynchronous read (S2MM)
+ * and write (MM2S) channel operation. It can be configured to have either
+ * one channel or two channels. If configured as two channels, one is to
+ * transmit to the video device (MM2S) and another is to receive from the
+ * video device (S2MM). Initialization, status, interrupt and management
+ * registers are accessed through an AXI4-Lite slave interface.
+ *
+ * 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/dmapool.h>
+#include <linux/dma/xilinx_dma.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_platform.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+
+#include "../dmaengine.h"
+
+/* Register/Descriptor Offsets */
+#define XILINX_VDMA_MM2S_CTRL_OFFSET 0x0000
+#define XILINX_VDMA_S2MM_CTRL_OFFSET 0x0030
+#define XILINX_VDMA_MM2S_DESC_OFFSET 0x0050
+#define XILINX_VDMA_S2MM_DESC_OFFSET 0x00a0
+
+/* Control Registers */
+#define XILINX_VDMA_REG_DMACR 0x0000
+#define XILINX_VDMA_DMACR_DELAY_MAX 0xff
+#define XILINX_VDMA_DMACR_DELAY_SHIFT 24
+#define XILINX_VDMA_DMACR_FRAME_COUNT_MAX 0xff
+#define XILINX_VDMA_DMACR_FRAME_COUNT_SHIFT 16
+#define XILINX_VDMA_DMACR_ERR_IRQ BIT(14)
+#define XILINX_VDMA_DMACR_DLY_CNT_IRQ BIT(13)
+#define XILINX_VDMA_DMACR_FRM_CNT_IRQ BIT(12)
+#define XILINX_VDMA_DMACR_MASTER_SHIFT 8
+#define XILINX_VDMA_DMACR_FSYNCSRC_SHIFT 5
+#define XILINX_VDMA_DMACR_FRAMECNT_EN BIT(4)
+#define XILINX_VDMA_DMACR_GENLOCK_EN BIT(3)
+#define XILINX_VDMA_DMACR_RESET BIT(2)
+#define XILINX_VDMA_DMACR_CIRC_EN BIT(1)
+#define XILINX_VDMA_DMACR_RUNSTOP BIT(0)
+#define XILINX_VDMA_DMACR_FSYNCSRC_MASK GENMASK(6, 5)
+
+#define XILINX_VDMA_REG_DMASR 0x0004
+#define XILINX_VDMA_DMASR_EOL_LATE_ERR BIT(15)
+#define XILINX_VDMA_DMASR_ERR_IRQ BIT(14)
+#define XILINX_VDMA_DMASR_DLY_CNT_IRQ BIT(13)
+#define XILINX_VDMA_DMASR_FRM_CNT_IRQ BIT(12)
+#define XILINX_VDMA_DMASR_SOF_LATE_ERR BIT(11)
+#define XILINX_VDMA_DMASR_SG_DEC_ERR BIT(10)
+#define XILINX_VDMA_DMASR_SG_SLV_ERR BIT(9)
+#define XILINX_VDMA_DMASR_EOF_EARLY_ERR BIT(8)
+#define XILINX_VDMA_DMASR_SOF_EARLY_ERR BIT(7)
+#define XILINX_VDMA_DMASR_DMA_DEC_ERR BIT(6)
+#define XILINX_VDMA_DMASR_DMA_SLAVE_ERR BIT(5)
+#define XILINX_VDMA_DMASR_DMA_INT_ERR BIT(4)
+#define XILINX_VDMA_DMASR_IDLE BIT(1)
+#define XILINX_VDMA_DMASR_HALTED BIT(0)
+#define XILINX_VDMA_DMASR_DELAY_MASK GENMASK(31, 24)
+#define XILINX_VDMA_DMASR_FRAME_COUNT_MASK GENMASK(23, 16)
+
+#define XILINX_VDMA_REG_CURDESC 0x0008
+#define XILINX_VDMA_REG_TAILDESC 0x0010
+#define XILINX_VDMA_REG_REG_INDEX 0x0014
+#define XILINX_VDMA_REG_FRMSTORE 0x0018
+#define XILINX_VDMA_REG_THRESHOLD 0x001c
+#define XILINX_VDMA_REG_FRMPTR_STS 0x0024
+#define XILINX_VDMA_REG_PARK_PTR 0x0028
+#define XILINX_VDMA_PARK_PTR_WR_REF_SHIFT 8
+#define XILINX_VDMA_PARK_PTR_RD_REF_SHIFT 0
+#define XILINX_VDMA_REG_VDMA_VERSION 0x002c
+
+/* Register Direct Mode Registers */
+#define XILINX_VDMA_REG_VSIZE 0x0000
+#define XILINX_VDMA_REG_HSIZE 0x0004
+
+#define XILINX_VDMA_REG_FRMDLY_STRIDE 0x0008
+#define XILINX_VDMA_FRMDLY_STRIDE_FRMDLY_SHIFT 24
+#define XILINX_VDMA_FRMDLY_STRIDE_STRIDE_SHIFT 0
+
+#define XILINX_VDMA_REG_START_ADDRESS(n) (0x000c + 4 * (n))
+
+/* HW specific definitions */
+#define XILINX_VDMA_MAX_CHANS_PER_DEVICE 0x2
+
+#define XILINX_VDMA_DMAXR_ALL_IRQ_MASK \
+ (XILINX_VDMA_DMASR_FRM_CNT_IRQ | \
+ XILINX_VDMA_DMASR_DLY_CNT_IRQ | \
+ XILINX_VDMA_DMASR_ERR_IRQ)
+
+#define XILINX_VDMA_DMASR_ALL_ERR_MASK \
+ (XILINX_VDMA_DMASR_EOL_LATE_ERR | \
+ XILINX_VDMA_DMASR_SOF_LATE_ERR | \
+ XILINX_VDMA_DMASR_SG_DEC_ERR | \
+ XILINX_VDMA_DMASR_SG_SLV_ERR | \
+ XILINX_VDMA_DMASR_EOF_EARLY_ERR | \
+ XILINX_VDMA_DMASR_SOF_EARLY_ERR | \
+ XILINX_VDMA_DMASR_DMA_DEC_ERR | \
+ XILINX_VDMA_DMASR_DMA_SLAVE_ERR | \
+ XILINX_VDMA_DMASR_DMA_INT_ERR)
+
+/*
+ * Recoverable errors are DMA Internal error, SOF Early, EOF Early
+ * and SOF Late. They are only recoverable when C_FLUSH_ON_FSYNC
+ * is enabled in the h/w system.
+ */
+#define XILINX_VDMA_DMASR_ERR_RECOVER_MASK \
+ (XILINX_VDMA_DMASR_SOF_LATE_ERR | \
+ XILINX_VDMA_DMASR_EOF_EARLY_ERR | \
+ XILINX_VDMA_DMASR_SOF_EARLY_ERR | \
+ XILINX_VDMA_DMASR_DMA_INT_ERR)
+
+/* Axi VDMA Flush on Fsync bits */
+#define XILINX_VDMA_FLUSH_S2MM 3
+#define XILINX_VDMA_FLUSH_MM2S 2
+#define XILINX_VDMA_FLUSH_BOTH 1
+
+/* Delay loop counter to prevent hardware failure */
+#define XILINX_VDMA_LOOP_COUNT 1000000
+
+/**
+ * struct xilinx_vdma_desc_hw - Hardware Descriptor
+ * @next_desc: Next Descriptor Pointer @0x00
+ * @pad1: Reserved @0x04
+ * @buf_addr: Buffer address @0x08
+ * @pad2: Reserved @0x0C
+ * @vsize: Vertical Size @0x10
+ * @hsize: Horizontal Size @0x14
+ * @stride: Number of bytes between the first
+ * pixels of each horizontal line @0x18
+ */
+struct xilinx_vdma_desc_hw {
+ u32 next_desc;
+ u32 pad1;
+ u32 buf_addr;
+ u32 pad2;
+ u32 vsize;
+ u32 hsize;
+ u32 stride;
+} __aligned(64);
+
+/**
+ * struct xilinx_vdma_tx_segment - Descriptor segment
+ * @hw: Hardware descriptor
+ * @node: Node in the descriptor segments list
+ * @phys: Physical address of segment
+ */
+struct xilinx_vdma_tx_segment {
+ struct xilinx_vdma_desc_hw hw;
+ struct list_head node;
+ dma_addr_t phys;
+} __aligned(64);
+
+/**
+ * struct xilinx_vdma_tx_descriptor - Per Transaction structure
+ * @async_tx: Async transaction descriptor
+ * @segments: TX segments list
+ * @node: Node in the channel descriptors list
+ */
+struct xilinx_vdma_tx_descriptor {
+ struct dma_async_tx_descriptor async_tx;
+ struct list_head segments;
+ struct list_head node;
+};
+
+/**
+ * struct xilinx_vdma_chan - Driver specific VDMA channel structure
+ * @xdev: Driver specific device structure
+ * @ctrl_offset: Control registers offset
+ * @desc_offset: TX descriptor registers offset
+ * @lock: Descriptor operation lock
+ * @pending_list: Descriptors waiting
+ * @active_desc: Active descriptor
+ * @allocated_desc: Allocated descriptor
+ * @done_list: Complete descriptors
+ * @common: DMA common channel
+ * @desc_pool: Descriptors pool
+ * @dev: The dma device
+ * @irq: Channel IRQ
+ * @id: Channel ID
+ * @direction: Transfer direction
+ * @num_frms: Number of frames
+ * @has_sg: Support scatter transfers
+ * @genlock: Support genlock mode
+ * @err: Channel has errors
+ * @tasklet: Cleanup work after irq
+ * @config: Device configuration info
+ * @flush_on_fsync: Flush on Frame sync
+ */
+struct xilinx_vdma_chan {
+ struct xilinx_vdma_device *xdev;
+ u32 ctrl_offset;
+ u32 desc_offset;
+ spinlock_t lock;
+ struct list_head pending_list;
+ struct xilinx_vdma_tx_descriptor *active_desc;
+ struct xilinx_vdma_tx_descriptor *allocated_desc;
+ struct list_head done_list;
+ struct dma_chan common;
+ struct dma_pool *desc_pool;
+ struct device *dev;
+ int irq;
+ int id;
+ enum dma_transfer_direction direction;
+ int num_frms;
+ bool has_sg;
+ bool genlock;
+ bool err;
+ struct tasklet_struct tasklet;
+ struct xilinx_vdma_config config;
+ bool flush_on_fsync;
+};
+
+/**
+ * struct xilinx_vdma_device - VDMA device structure
+ * @regs: I/O mapped base address
+ * @dev: Device Structure
+ * @common: DMA device structure
+ * @chan: Driver specific VDMA channel
+ * @has_sg: Specifies whether Scatter-Gather is present or not
+ * @flush_on_fsync: Flush on frame sync
+ */
+struct xilinx_vdma_device {
+ void __iomem *regs;
+ struct device *dev;
+ struct dma_device common;
+ struct xilinx_vdma_chan *chan[XILINX_VDMA_MAX_CHANS_PER_DEVICE];
+ bool has_sg;
+ u32 flush_on_fsync;
+};
+
+/* Macros */
+#define to_xilinx_chan(chan) \
+ container_of(chan, struct xilinx_vdma_chan, common)
+#define to_vdma_tx_descriptor(tx) \
+ container_of(tx, struct xilinx_vdma_tx_descriptor, async_tx)
+
+/* IO accessors */
+static inline u32 vdma_read(struct xilinx_vdma_chan *chan, u32 reg)
+{
+ return ioread32(chan->xdev->regs + reg);
+}
+
+static inline void vdma_write(struct xilinx_vdma_chan *chan, u32 reg, u32 value)
+{
+ iowrite32(value, chan->xdev->regs + reg);
+}
+
+static inline void vdma_desc_write(struct xilinx_vdma_chan *chan, u32 reg,
+ u32 value)
+{
+ vdma_write(chan, chan->desc_offset + reg, value);
+}
+
+static inline u32 vdma_ctrl_read(struct xilinx_vdma_chan *chan, u32 reg)
+{
+ return vdma_read(chan, chan->ctrl_offset + reg);
+}
+
+static inline void vdma_ctrl_write(struct xilinx_vdma_chan *chan, u32 reg,
+ u32 value)
+{
+ vdma_write(chan, chan->ctrl_offset + reg, value);
+}
+
+static inline void vdma_ctrl_clr(struct xilinx_vdma_chan *chan, u32 reg,
+ u32 clr)
+{
+ vdma_ctrl_write(chan, reg, vdma_ctrl_read(chan, reg) & ~clr);
+}
+
+static inline void vdma_ctrl_set(struct xilinx_vdma_chan *chan, u32 reg,
+ u32 set)
+{
+ vdma_ctrl_write(chan, reg, vdma_ctrl_read(chan, reg) | set);
+}
+
+/* -----------------------------------------------------------------------------
+ * Descriptors and segments alloc and free
+ */
+
+/**
+ * xilinx_vdma_alloc_tx_segment - Allocate transaction segment
+ * @chan: Driver specific VDMA channel
+ *
+ * Return: The allocated segment on success and NULL on failure.
+ */
+static struct xilinx_vdma_tx_segment *
+xilinx_vdma_alloc_tx_segment(struct xilinx_vdma_chan *chan)
+{
+ struct xilinx_vdma_tx_segment *segment;
+ dma_addr_t phys;
+
+ segment = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &phys);
+ if (!segment)
+ return NULL;
+
+ memset(segment, 0, sizeof(*segment));
+ segment->phys = phys;
+
+ return segment;
+}
+
+/**
+ * xilinx_vdma_free_tx_segment - Free transaction segment
+ * @chan: Driver specific VDMA channel
+ * @segment: VDMA transaction segment
+ */
+static void xilinx_vdma_free_tx_segment(struct xilinx_vdma_chan *chan,
+ struct xilinx_vdma_tx_segment *segment)
+{
+ dma_pool_free(chan->desc_pool, segment, segment->phys);
+}
+
+/**
+ * xilinx_vdma_tx_descriptor - Allocate transaction descriptor
+ * @chan: Driver specific VDMA channel
+ *
+ * Return: The allocated descriptor on success and NULL on failure.
+ */
+static struct xilinx_vdma_tx_descriptor *
+xilinx_vdma_alloc_tx_descriptor(struct xilinx_vdma_chan *chan)
+{
+ struct xilinx_vdma_tx_descriptor *desc;
+ unsigned long flags;
+
+ if (chan->allocated_desc)
+ return chan->allocated_desc;
+
+ desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+ if (!desc)
+ return NULL;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ chan->allocated_desc = desc;
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ INIT_LIST_HEAD(&desc->segments);
+
+ return desc;
+}
+
+/**
+ * xilinx_vdma_free_tx_descriptor - Free transaction descriptor
+ * @chan: Driver specific VDMA channel
+ * @desc: VDMA transaction descriptor
+ */
+static void
+xilinx_vdma_free_tx_descriptor(struct xilinx_vdma_chan *chan,
+ struct xilinx_vdma_tx_descriptor *desc)
+{
+ struct xilinx_vdma_tx_segment *segment, *next;
+
+ if (!desc)
+ return;
+
+ list_for_each_entry_safe(segment, next, &desc->segments, node) {
+ list_del(&segment->node);
+ xilinx_vdma_free_tx_segment(chan, segment);
+ }
+
+ kfree(desc);
+}
+
+/* Required functions */
+
+/**
+ * xilinx_vdma_free_desc_list - Free descriptors list
+ * @chan: Driver specific VDMA channel
+ * @list: List to parse and delete the descriptor
+ */
+static void xilinx_vdma_free_desc_list(struct xilinx_vdma_chan *chan,
+ struct list_head *list)
+{
+ struct xilinx_vdma_tx_descriptor *desc, *next;
+
+ list_for_each_entry_safe(desc, next, list, node) {
+ list_del(&desc->node);
+ xilinx_vdma_free_tx_descriptor(chan, desc);
+ }
+}
+
+/**
+ * xilinx_vdma_free_descriptors - Free channel descriptors
+ * @chan: Driver specific VDMA channel
+ */
+static void xilinx_vdma_free_descriptors(struct xilinx_vdma_chan *chan)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+
+ xilinx_vdma_free_desc_list(chan, &chan->pending_list);
+ xilinx_vdma_free_desc_list(chan, &chan->done_list);
+
+ xilinx_vdma_free_tx_descriptor(chan, chan->active_desc);
+ chan->active_desc = NULL;
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+/**
+ * xilinx_vdma_free_chan_resources - Free channel resources
+ * @dchan: DMA channel
+ */
+static void xilinx_vdma_free_chan_resources(struct dma_chan *dchan)
+{
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
+
+ dev_dbg(chan->dev, "Free all channel resources.\n");
+
+ xilinx_vdma_free_descriptors(chan);
+ dma_pool_destroy(chan->desc_pool);
+ chan->desc_pool = NULL;
+}
+
+/**
+ * xilinx_vdma_chan_desc_cleanup - Clean channel descriptors
+ * @chan: Driver specific VDMA channel
+ */
+static void xilinx_vdma_chan_desc_cleanup(struct xilinx_vdma_chan *chan)
+{
+ struct xilinx_vdma_tx_descriptor *desc, *next;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+
+ list_for_each_entry_safe(desc, next, &chan->done_list, node) {
+ dma_async_tx_callback callback;
+ void *callback_param;
+
+ /* Remove from the list of running transactions */
+ list_del(&desc->node);
+
+ /* Run the link descriptor callback function */
+ callback = desc->async_tx.callback;
+ callback_param = desc->async_tx.callback_param;
+ if (callback) {
+ spin_unlock_irqrestore(&chan->lock, flags);
+ callback(callback_param);
+ spin_lock_irqsave(&chan->lock, flags);
+ }
+
+ /* Run any dependencies, then free the descriptor */
+ dma_run_dependencies(&desc->async_tx);
+ xilinx_vdma_free_tx_descriptor(chan, desc);
+ }
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+/**
+ * xilinx_vdma_do_tasklet - Schedule completion tasklet
+ * @data: Pointer to the Xilinx VDMA channel structure
+ */
+static void xilinx_vdma_do_tasklet(unsigned long data)
+{
+ struct xilinx_vdma_chan *chan = (struct xilinx_vdma_chan *)data;
+
+ xilinx_vdma_chan_desc_cleanup(chan);
+}
+
+/**
+ * xilinx_vdma_alloc_chan_resources - Allocate channel resources
+ * @dchan: DMA channel
+ *
+ * Return: '0' on success and failure value on error
+ */
+static int xilinx_vdma_alloc_chan_resources(struct dma_chan *dchan)
+{
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
+
+ /* Has this channel already been allocated? */
+ if (chan->desc_pool)
+ return 0;
+
+ /*
+ * We need the descriptor to be aligned to 64bytes
+ * for meeting Xilinx VDMA specification requirement.
+ */
+ chan->desc_pool = dma_pool_create("xilinx_vdma_desc_pool",
+ chan->dev,
+ sizeof(struct xilinx_vdma_tx_segment),
+ __alignof__(struct xilinx_vdma_tx_segment), 0);
+ if (!chan->desc_pool) {
+ dev_err(chan->dev,
+ "unable to allocate channel %d descriptor pool\n",
+ chan->id);
+ return -ENOMEM;
+ }
+
+ dma_cookie_init(dchan);
+ return 0;
+}
+
+/**
+ * xilinx_vdma_tx_status - Get VDMA transaction status
+ * @dchan: DMA channel
+ * @cookie: Transaction identifier
+ * @txstate: Transaction state
+ *
+ * Return: DMA transaction status
+ */
+static enum dma_status xilinx_vdma_tx_status(struct dma_chan *dchan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ return dma_cookie_status(dchan, cookie, txstate);
+}
+
+/**
+ * xilinx_vdma_is_running - Check if VDMA channel is running
+ * @chan: Driver specific VDMA channel
+ *
+ * Return: '1' if running, '0' if not.
+ */
+static bool xilinx_vdma_is_running(struct xilinx_vdma_chan *chan)
+{
+ return !(vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR) &
+ XILINX_VDMA_DMASR_HALTED) &&
+ (vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR) &
+ XILINX_VDMA_DMACR_RUNSTOP);
+}
+
+/**
+ * xilinx_vdma_is_idle - Check if VDMA channel is idle
+ * @chan: Driver specific VDMA channel
+ *
+ * Return: '1' if idle, '0' if not.
+ */
+static bool xilinx_vdma_is_idle(struct xilinx_vdma_chan *chan)
+{
+ return vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR) &
+ XILINX_VDMA_DMASR_IDLE;
+}
+
+/**
+ * xilinx_vdma_halt - Halt VDMA channel
+ * @chan: Driver specific VDMA channel
+ */
+static void xilinx_vdma_halt(struct xilinx_vdma_chan *chan)
+{
+ int loop = XILINX_VDMA_LOOP_COUNT;
+
+ vdma_ctrl_clr(chan, XILINX_VDMA_REG_DMACR, XILINX_VDMA_DMACR_RUNSTOP);
+
+ /* Wait for the hardware to halt */
+ do {
+ if (vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR) &
+ XILINX_VDMA_DMASR_HALTED)
+ break;
+ } while (loop--);
+
+ if (!loop) {
+ dev_err(chan->dev, "Cannot stop channel %p: %x\n",
+ chan, vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR));
+ chan->err = true;
+ }
+
+ return;
+}
+
+/**
+ * xilinx_vdma_start - Start VDMA channel
+ * @chan: Driver specific VDMA channel
+ */
+static void xilinx_vdma_start(struct xilinx_vdma_chan *chan)
+{
+ int loop = XILINX_VDMA_LOOP_COUNT;
+
+ vdma_ctrl_set(chan, XILINX_VDMA_REG_DMACR, XILINX_VDMA_DMACR_RUNSTOP);
+
+ /* Wait for the hardware to start */
+ do {
+ if (!(vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR) &
+ XILINX_VDMA_DMASR_HALTED))
+ break;
+ } while (loop--);
+
+ if (!loop) {
+ dev_err(chan->dev, "Cannot start channel %p: %x\n",
+ chan, vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR));
+
+ chan->err = true;
+ }
+
+ return;
+}
+
+/**
+ * xilinx_vdma_start_transfer - Starts VDMA transfer
+ * @chan: Driver specific channel struct pointer
+ */
+static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan)
+{
+ struct xilinx_vdma_config *config = &chan->config;
+ struct xilinx_vdma_tx_descriptor *desc;
+ unsigned long flags;
+ u32 reg;
+ struct xilinx_vdma_tx_segment *head, *tail = NULL;
+
+ if (chan->err)
+ return;
+
+ spin_lock_irqsave(&chan->lock, flags);
+
+ /* There's already an active descriptor, bail out. */
+ if (chan->active_desc)
+ goto out_unlock;
+
+ if (list_empty(&chan->pending_list))
+ goto out_unlock;
+
+ desc = list_first_entry(&chan->pending_list,
+ struct xilinx_vdma_tx_descriptor, node);
+
+ /* If it is SG mode and hardware is busy, cannot submit */
+ if (chan->has_sg && xilinx_vdma_is_running(chan) &&
+ !xilinx_vdma_is_idle(chan)) {
+ dev_dbg(chan->dev, "DMA controller still busy\n");
+ goto out_unlock;
+ }
+
+ /*
+ * If hardware is idle, then all descriptors on the running lists are
+ * done, start new transfers
+ */
+ if (chan->has_sg) {
+ head = list_first_entry(&desc->segments,
+ struct xilinx_vdma_tx_segment, node);
+ tail = list_entry(desc->segments.prev,
+ struct xilinx_vdma_tx_segment, node);
+
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_CURDESC, head->phys);
+ }
+
+ /* Configure the hardware using info in the config structure */
+ reg = vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR);
+
+ if (config->frm_cnt_en)
+ reg |= XILINX_VDMA_DMACR_FRAMECNT_EN;
+ else
+ reg &= ~XILINX_VDMA_DMACR_FRAMECNT_EN;
+
+ /*
+ * With SG, start with circular mode, so that BDs can be fetched.
+ * In direct register mode, if not parking, enable circular mode
+ */
+ if (chan->has_sg || !config->park)
+ reg |= XILINX_VDMA_DMACR_CIRC_EN;
+
+ if (config->park)
+ reg &= ~XILINX_VDMA_DMACR_CIRC_EN;
+
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_DMACR, reg);
+
+ if (config->park && (config->park_frm >= 0) &&
+ (config->park_frm < chan->num_frms)) {
+ if (chan->direction == DMA_MEM_TO_DEV)
+ vdma_write(chan, XILINX_VDMA_REG_PARK_PTR,
+ config->park_frm <<
+ XILINX_VDMA_PARK_PTR_RD_REF_SHIFT);
+ else
+ vdma_write(chan, XILINX_VDMA_REG_PARK_PTR,
+ config->park_frm <<
+ XILINX_VDMA_PARK_PTR_WR_REF_SHIFT);
+ }
+
+ /* Start the hardware */
+ xilinx_vdma_start(chan);
+
+ if (chan->err)
+ goto out_unlock;
+
+ /* Start the transfer */
+ if (chan->has_sg) {
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_TAILDESC, tail->phys);
+ } else {
+ struct xilinx_vdma_tx_segment *segment, *last = NULL;
+ int i = 0;
+
+ list_for_each_entry(segment, &desc->segments, node) {
+ vdma_desc_write(chan,
+ XILINX_VDMA_REG_START_ADDRESS(i++),
+ segment->hw.buf_addr);
+ last = segment;
+ }
+
+ if (!last)
+ goto out_unlock;
+
+ /* HW expects these parameters to be same for one transaction */
+ vdma_desc_write(chan, XILINX_VDMA_REG_HSIZE, last->hw.hsize);
+ vdma_desc_write(chan, XILINX_VDMA_REG_FRMDLY_STRIDE,
+ last->hw.stride);
+ vdma_desc_write(chan, XILINX_VDMA_REG_VSIZE, last->hw.vsize);
+ }
+
+ list_del(&desc->node);
+ chan->active_desc = desc;
+
+out_unlock:
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+/**
+ * xilinx_vdma_issue_pending - Issue pending transactions
+ * @dchan: DMA channel
+ */
+static void xilinx_vdma_issue_pending(struct dma_chan *dchan)
+{
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
+
+ xilinx_vdma_start_transfer(chan);
+}
+
+/**
+ * xilinx_vdma_complete_descriptor - Mark the active descriptor as complete
+ * @chan : xilinx DMA channel
+ *
+ * CONTEXT: hardirq
+ */
+static void xilinx_vdma_complete_descriptor(struct xilinx_vdma_chan *chan)
+{
+ struct xilinx_vdma_tx_descriptor *desc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+
+ desc = chan->active_desc;
+ if (!desc) {
+ dev_dbg(chan->dev, "no running descriptors\n");
+ goto out_unlock;
+ }
+
+ dma_cookie_complete(&desc->async_tx);
+ list_add_tail(&desc->node, &chan->done_list);
+
+ chan->active_desc = NULL;
+
+out_unlock:
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+
+/**
+ * xilinx_vdma_reset - Reset VDMA channel
+ * @chan: Driver specific VDMA channel
+ *
+ * Return: '0' on success and failure value on error
+ */
+static int xilinx_vdma_reset(struct xilinx_vdma_chan *chan)
+{
+ int loop = XILINX_VDMA_LOOP_COUNT;
+ u32 tmp;
+
+ vdma_ctrl_set(chan, XILINX_VDMA_REG_DMACR, XILINX_VDMA_DMACR_RESET);
+
+ tmp = vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR) &
+ XILINX_VDMA_DMACR_RESET;
+
+ /* Wait for the hardware to finish reset */
+ do {
+ tmp = vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR) &
+ XILINX_VDMA_DMACR_RESET;
+ } while (loop-- && tmp);
+
+ if (!loop) {
+ dev_err(chan->dev, "reset timeout, cr %x, sr %x\n",
+ vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR),
+ vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR));
+ return -ETIMEDOUT;
+ }
+
+ chan->err = false;
+
+ return 0;
+}
+
+/**
+ * xilinx_vdma_chan_reset - Reset VDMA channel and enable interrupts
+ * @chan: Driver specific VDMA channel
+ *
+ * Return: '0' on success and failure value on error
+ */
+static int xilinx_vdma_chan_reset(struct xilinx_vdma_chan *chan)
+{
+ int err;
+
+ /* Reset VDMA */
+ err = xilinx_vdma_reset(chan);
+ if (err)
+ return err;
+
+ /* Enable interrupts */
+ vdma_ctrl_set(chan, XILINX_VDMA_REG_DMACR,
+ XILINX_VDMA_DMAXR_ALL_IRQ_MASK);
+
+ return 0;
+}
+
+/**
+ * xilinx_vdma_irq_handler - VDMA Interrupt handler
+ * @irq: IRQ number
+ * @data: Pointer to the Xilinx VDMA channel structure
+ *
+ * Return: IRQ_HANDLED/IRQ_NONE
+ */
+static irqreturn_t xilinx_vdma_irq_handler(int irq, void *data)
+{
+ struct xilinx_vdma_chan *chan = data;
+ u32 status;
+
+ /* Read the status and ack the interrupts. */
+ status = vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR);
+ if (!(status & XILINX_VDMA_DMAXR_ALL_IRQ_MASK))
+ return IRQ_NONE;
+
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_DMASR,
+ status & XILINX_VDMA_DMAXR_ALL_IRQ_MASK);
+
+ if (status & XILINX_VDMA_DMASR_ERR_IRQ) {
+ /*
+ * An error occurred. If C_FLUSH_ON_FSYNC is enabled and the
+ * error is recoverable, ignore it. Otherwise flag the error.
+ *
+ * Only recoverable errors can be cleared in the DMASR register,
+ * make sure not to write to other error bits to 1.
+ */
+ u32 errors = status & XILINX_VDMA_DMASR_ALL_ERR_MASK;
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_DMASR,
+ errors & XILINX_VDMA_DMASR_ERR_RECOVER_MASK);
+
+ if (!chan->flush_on_fsync ||
+ (errors & ~XILINX_VDMA_DMASR_ERR_RECOVER_MASK)) {
+ dev_err(chan->dev,
+ "Channel %p has errors %x, cdr %x tdr %x\n",
+ chan, errors,
+ vdma_ctrl_read(chan, XILINX_VDMA_REG_CURDESC),
+ vdma_ctrl_read(chan, XILINX_VDMA_REG_TAILDESC));
+ chan->err = true;
+ }
+ }
+
+ if (status & XILINX_VDMA_DMASR_DLY_CNT_IRQ) {
+ /*
+ * Device takes too long to do the transfer when user requires
+ * responsiveness.
+ */
+ dev_dbg(chan->dev, "Inter-packet latency too long\n");
+ }
+
+ if (status & XILINX_VDMA_DMASR_FRM_CNT_IRQ) {
+ xilinx_vdma_complete_descriptor(chan);
+ xilinx_vdma_start_transfer(chan);
+ }
+
+ tasklet_schedule(&chan->tasklet);
+ return IRQ_HANDLED;
+}
+
+/**
+ * xilinx_vdma_tx_submit - Submit DMA transaction
+ * @tx: Async transaction descriptor
+ *
+ * Return: cookie value on success and failure value on error
+ */
+static dma_cookie_t xilinx_vdma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ struct xilinx_vdma_tx_descriptor *desc = to_vdma_tx_descriptor(tx);
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(tx->chan);
+ dma_cookie_t cookie;
+ unsigned long flags;
+ int err;
+
+ if (chan->err) {
+ /*
+ * If reset fails, need to hard reset the system.
+ * Channel is no longer functional
+ */
+ err = xilinx_vdma_chan_reset(chan);
+ if (err < 0)
+ return err;
+ }
+
+ spin_lock_irqsave(&chan->lock, flags);
+
+ cookie = dma_cookie_assign(tx);
+
+ /* Append the transaction to the pending transactions queue. */
+ list_add_tail(&desc->node, &chan->pending_list);
+
+ /* Free the allocated desc */
+ chan->allocated_desc = NULL;
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ return cookie;
+}
+
+/**
+ * xilinx_vdma_dma_prep_interleaved - prepare a descriptor for a
+ * DMA_SLAVE transaction
+ * @dchan: DMA channel
+ * @xt: Interleaved template pointer
+ * @flags: transfer ack flags
+ *
+ * Return: Async transaction descriptor on success and NULL on failure
+ */
+static struct dma_async_tx_descriptor *
+xilinx_vdma_dma_prep_interleaved(struct dma_chan *dchan,
+ struct dma_interleaved_template *xt,
+ unsigned long flags)
+{
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
+ struct xilinx_vdma_tx_descriptor *desc;
+ struct xilinx_vdma_tx_segment *segment, *prev = NULL;
+ struct xilinx_vdma_desc_hw *hw;
+
+ if (!is_slave_direction(xt->dir))
+ return NULL;
+
+ if (!xt->numf || !xt->sgl[0].size)
+ return NULL;
+
+ if (xt->frame_size != 1)
+ return NULL;
+
+ /* Allocate a transaction descriptor. */
+ desc = xilinx_vdma_alloc_tx_descriptor(chan);
+ if (!desc)
+ return NULL;
+
+ dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
+ desc->async_tx.tx_submit = xilinx_vdma_tx_submit;
+ async_tx_ack(&desc->async_tx);
+
+ /* Allocate the link descriptor from DMA pool */
+ segment = xilinx_vdma_alloc_tx_segment(chan);
+ if (!segment)
+ goto error;
+
+ /* Fill in the hardware descriptor */
+ hw = &segment->hw;
+ hw->vsize = xt->numf;
+ hw->hsize = xt->sgl[0].size;
+ hw->stride = (xt->sgl[0].icg + xt->sgl[0].size) <<
+ XILINX_VDMA_FRMDLY_STRIDE_STRIDE_SHIFT;
+ hw->stride |= chan->config.frm_dly <<
+ XILINX_VDMA_FRMDLY_STRIDE_FRMDLY_SHIFT;
+
+ if (xt->dir != DMA_MEM_TO_DEV)
+ hw->buf_addr = xt->dst_start;
+ else
+ hw->buf_addr = xt->src_start;
+
+ /* Link the previous next descriptor to current */
+ if (!list_empty(&desc->segments)) {
+ prev = list_last_entry(&desc->segments,
+ struct xilinx_vdma_tx_segment, node);
+ prev->hw.next_desc = segment->phys;
+ }
+
+ /* Insert the segment into the descriptor segments list. */
+ list_add_tail(&segment->node, &desc->segments);
+
+ prev = segment;
+
+ /* Link the last hardware descriptor with the first. */
+ segment = list_first_entry(&desc->segments,
+ struct xilinx_vdma_tx_segment, node);
+ prev->hw.next_desc = segment->phys;
+
+ return &desc->async_tx;
+
+error:
+ xilinx_vdma_free_tx_descriptor(chan, desc);
+ return NULL;
+}
+
+/**
+ * xilinx_vdma_terminate_all - Halt the channel and free descriptors
+ * @chan: Driver specific VDMA Channel pointer
+ */
+static int xilinx_vdma_terminate_all(struct dma_chan *dchan)
+{
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
+
+ /* Halt the DMA engine */
+ xilinx_vdma_halt(chan);
+
+ /* Remove and free all of the descriptors in the lists */
+ xilinx_vdma_free_descriptors(chan);
+
+ return 0;
+}
+
+/**
+ * xilinx_vdma_channel_set_config - Configure VDMA channel
+ * Run-time configuration for Axi VDMA, supports:
+ * . halt the channel
+ * . configure interrupt coalescing and inter-packet delay threshold
+ * . start/stop parking
+ * . enable genlock
+ *
+ * @dchan: DMA channel
+ * @cfg: VDMA device configuration pointer
+ *
+ * Return: '0' on success and failure value on error
+ */
+int xilinx_vdma_channel_set_config(struct dma_chan *dchan,
+ struct xilinx_vdma_config *cfg)
+{
+ struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
+ u32 dmacr;
+
+ if (cfg->reset)
+ return xilinx_vdma_chan_reset(chan);
+
+ dmacr = vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR);
+
+ chan->config.frm_dly = cfg->frm_dly;
+ chan->config.park = cfg->park;
+
+ /* genlock settings */
+ chan->config.gen_lock = cfg->gen_lock;
+ chan->config.master = cfg->master;
+
+ if (cfg->gen_lock && chan->genlock) {
+ dmacr |= XILINX_VDMA_DMACR_GENLOCK_EN;
+ dmacr |= cfg->master << XILINX_VDMA_DMACR_MASTER_SHIFT;
+ }
+
+ chan->config.frm_cnt_en = cfg->frm_cnt_en;
+ if (cfg->park)
+ chan->config.park_frm = cfg->park_frm;
+ else
+ chan->config.park_frm = -1;
+
+ chan->config.coalesc = cfg->coalesc;
+ chan->config.delay = cfg->delay;
+
+ if (cfg->coalesc <= XILINX_VDMA_DMACR_FRAME_COUNT_MAX) {
+ dmacr |= cfg->coalesc << XILINX_VDMA_DMACR_FRAME_COUNT_SHIFT;
+ chan->config.coalesc = cfg->coalesc;
+ }
+
+ if (cfg->delay <= XILINX_VDMA_DMACR_DELAY_MAX) {
+ dmacr |= cfg->delay << XILINX_VDMA_DMACR_DELAY_SHIFT;
+ chan->config.delay = cfg->delay;
+ }
+
+ /* FSync Source selection */
+ dmacr &= ~XILINX_VDMA_DMACR_FSYNCSRC_MASK;
+ dmacr |= cfg->ext_fsync << XILINX_VDMA_DMACR_FSYNCSRC_SHIFT;
+
+ vdma_ctrl_write(chan, XILINX_VDMA_REG_DMACR, dmacr);
+
+ return 0;
+}
+EXPORT_SYMBOL(xilinx_vdma_channel_set_config);
+
+/* -----------------------------------------------------------------------------
+ * Probe and remove
+ */
+
+/**
+ * xilinx_vdma_chan_remove - Per Channel remove function
+ * @chan: Driver specific VDMA channel
+ */
+static void xilinx_vdma_chan_remove(struct xilinx_vdma_chan *chan)
+{
+ /* Disable all interrupts */
+ vdma_ctrl_clr(chan, XILINX_VDMA_REG_DMACR,
+ XILINX_VDMA_DMAXR_ALL_IRQ_MASK);
+
+ if (chan->irq > 0)
+ free_irq(chan->irq, chan);
+
+ tasklet_kill(&chan->tasklet);
+
+ list_del(&chan->common.device_node);
+}
+
+/**
+ * xilinx_vdma_chan_probe - Per Channel Probing
+ * It get channel features from the device tree entry and
+ * initialize special channel handling routines
+ *
+ * @xdev: Driver specific device structure
+ * @node: Device node
+ *
+ * Return: '0' on success and failure value on error
+ */
+static int xilinx_vdma_chan_probe(struct xilinx_vdma_device *xdev,
+ struct device_node *node)
+{
+ struct xilinx_vdma_chan *chan;
+ bool has_dre = false;
+ u32 value, width;
+ int err;
+
+ /* Allocate and initialize the channel structure */
+ chan = devm_kzalloc(xdev->dev, sizeof(*chan), GFP_KERNEL);
+ if (!chan)
+ return -ENOMEM;
+
+ chan->dev = xdev->dev;
+ chan->xdev = xdev;
+ chan->has_sg = xdev->has_sg;
+
+ spin_lock_init(&chan->lock);
+ INIT_LIST_HEAD(&chan->pending_list);
+ INIT_LIST_HEAD(&chan->done_list);
+
+ /* Retrieve the channel properties from the device tree */
+ has_dre = of_property_read_bool(node, "xlnx,include-dre");
+
+ chan->genlock = of_property_read_bool(node, "xlnx,genlock-mode");
+
+ err = of_property_read_u32(node, "xlnx,datawidth", &value);
+ if (err) {
+ dev_err(xdev->dev, "missing xlnx,datawidth property\n");
+ return err;
+ }
+ width = value >> 3; /* Convert bits to bytes */
+
+ /* If data width is greater than 8 bytes, DRE is not in hw */
+ if (width > 8)
+ has_dre = false;
+
+ if (!has_dre)
+ xdev->common.copy_align = fls(width - 1);
+
+ if (of_device_is_compatible(node, "xlnx,axi-vdma-mm2s-channel")) {
+ chan->direction = DMA_MEM_TO_DEV;
+ chan->id = 0;
+
+ chan->ctrl_offset = XILINX_VDMA_MM2S_CTRL_OFFSET;
+ chan->desc_offset = XILINX_VDMA_MM2S_DESC_OFFSET;
+
+ if (xdev->flush_on_fsync == XILINX_VDMA_FLUSH_BOTH ||
+ xdev->flush_on_fsync == XILINX_VDMA_FLUSH_MM2S)
+ chan->flush_on_fsync = true;
+ } else if (of_device_is_compatible(node,
+ "xlnx,axi-vdma-s2mm-channel")) {
+ chan->direction = DMA_DEV_TO_MEM;
+ chan->id = 1;
+
+ chan->ctrl_offset = XILINX_VDMA_S2MM_CTRL_OFFSET;
+ chan->desc_offset = XILINX_VDMA_S2MM_DESC_OFFSET;
+
+ if (xdev->flush_on_fsync == XILINX_VDMA_FLUSH_BOTH ||
+ xdev->flush_on_fsync == XILINX_VDMA_FLUSH_S2MM)
+ chan->flush_on_fsync = true;
+ } else {
+ dev_err(xdev->dev, "Invalid channel compatible node\n");
+ return -EINVAL;
+ }
+
+ /* Request the interrupt */
+ chan->irq = irq_of_parse_and_map(node, 0);
+ err = request_irq(chan->irq, xilinx_vdma_irq_handler, IRQF_SHARED,
+ "xilinx-vdma-controller", chan);
+ if (err) {
+ dev_err(xdev->dev, "unable to request IRQ %d\n", chan->irq);
+ return err;
+ }
+
+ /* Initialize the tasklet */
+ tasklet_init(&chan->tasklet, xilinx_vdma_do_tasklet,
+ (unsigned long)chan);
+
+ /*
+ * Initialize the DMA channel and add it to the DMA engine channels
+ * list.
+ */
+ chan->common.device = &xdev->common;
+
+ list_add_tail(&chan->common.device_node, &xdev->common.channels);
+ xdev->chan[chan->id] = chan;
+
+ /* Reset the channel */
+ err = xilinx_vdma_chan_reset(chan);
+ if (err < 0) {
+ dev_err(xdev->dev, "Reset channel failed\n");
+ return err;
+ }
+
+ return 0;
+}
+
+/**
+ * of_dma_xilinx_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_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct xilinx_vdma_device *xdev = ofdma->of_dma_data;
+ int chan_id = dma_spec->args[0];
+
+ if (chan_id >= XILINX_VDMA_MAX_CHANS_PER_DEVICE)
+ return NULL;
+
+ return dma_get_slave_channel(&xdev->chan[chan_id]->common);
+}
+
+/**
+ * xilinx_vdma_probe - Driver probe function
+ * @pdev: Pointer to the platform_device structure
+ *
+ * Return: '0' on success and failure value on error
+ */
+static int xilinx_vdma_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct xilinx_vdma_device *xdev;
+ struct device_node *child;
+ struct resource *io;
+ u32 num_frames;
+ int i, err;
+
+ /* Allocate and initialize the DMA engine structure */
+ xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
+ if (!xdev)
+ return -ENOMEM;
+
+ xdev->dev = &pdev->dev;
+
+ /* Request and map I/O memory */
+ io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ xdev->regs = devm_ioremap_resource(&pdev->dev, io);
+ if (IS_ERR(xdev->regs))
+ return PTR_ERR(xdev->regs);
+
+ /* Retrieve the DMA engine properties from the device tree */
+ xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");
+
+ err = of_property_read_u32(node, "xlnx,num-fstores", &num_frames);
+ if (err < 0) {
+ dev_err(xdev->dev, "missing xlnx,num-fstores property\n");
+ return err;
+ }
+
+ err = of_property_read_u32(node, "xlnx,flush-fsync",
+ &xdev->flush_on_fsync);
+ if (err < 0)
+ dev_warn(xdev->dev, "missing xlnx,flush-fsync property\n");
+
+ /* Initialize the DMA engine */
+ xdev->common.dev = &pdev->dev;
+
+ INIT_LIST_HEAD(&xdev->common.channels);
+ dma_cap_set(DMA_SLAVE, xdev->common.cap_mask);
+ dma_cap_set(DMA_PRIVATE, xdev->common.cap_mask);
+
+ xdev->common.device_alloc_chan_resources =
+ xilinx_vdma_alloc_chan_resources;
+ xdev->common.device_free_chan_resources =
+ xilinx_vdma_free_chan_resources;
+ xdev->common.device_prep_interleaved_dma =
+ xilinx_vdma_dma_prep_interleaved;
+ xdev->common.device_terminate_all = xilinx_vdma_terminate_all;
+ xdev->common.device_tx_status = xilinx_vdma_tx_status;
+ xdev->common.device_issue_pending = xilinx_vdma_issue_pending;
+
+ platform_set_drvdata(pdev, xdev);
+
+ /* Initialize the channels */
+ for_each_child_of_node(node, child) {
+ err = xilinx_vdma_chan_probe(xdev, child);
+ if (err < 0)
+ goto error;
+ }
+
+ for (i = 0; i < XILINX_VDMA_MAX_CHANS_PER_DEVICE; i++)
+ if (xdev->chan[i])
+ xdev->chan[i]->num_frms = num_frames;
+
+ /* Register the DMA engine with the core */
+ dma_async_device_register(&xdev->common);
+
+ err = of_dma_controller_register(node, of_dma_xilinx_xlate,
+ xdev);
+ if (err < 0) {
+ dev_err(&pdev->dev, "Unable to register DMA to DT\n");
+ dma_async_device_unregister(&xdev->common);
+ goto error;
+ }
+
+ dev_info(&pdev->dev, "Xilinx AXI VDMA Engine Driver Probed!!\n");
+
+ return 0;
+
+error:
+ for (i = 0; i < XILINX_VDMA_MAX_CHANS_PER_DEVICE; i++)
+ if (xdev->chan[i])
+ xilinx_vdma_chan_remove(xdev->chan[i]);
+
+ return err;
+}
+
+/**
+ * xilinx_vdma_remove - Driver remove function
+ * @pdev: Pointer to the platform_device structure
+ *
+ * Return: Always '0'
+ */
+static int xilinx_vdma_remove(struct platform_device *pdev)
+{
+ struct xilinx_vdma_device *xdev = platform_get_drvdata(pdev);
+ int i;
+
+ of_dma_controller_free(pdev->dev.of_node);
+
+ dma_async_device_unregister(&xdev->common);
+
+ for (i = 0; i < XILINX_VDMA_MAX_CHANS_PER_DEVICE; i++)
+ if (xdev->chan[i])
+ xilinx_vdma_chan_remove(xdev->chan[i]);
+
+ return 0;
+}
+
+static const struct of_device_id xilinx_vdma_of_ids[] = {
+ { .compatible = "xlnx,axi-vdma-1.00.a",},
+ {}
+};
+
+static struct platform_driver xilinx_vdma_driver = {
+ .driver = {
+ .name = "xilinx-vdma",
+ .of_match_table = xilinx_vdma_of_ids,
+ },
+ .probe = xilinx_vdma_probe,
+ .remove = xilinx_vdma_remove,
+};
+
+module_platform_driver(xilinx_vdma_driver);
+
+MODULE_AUTHOR("Xilinx, Inc.");
+MODULE_DESCRIPTION("Xilinx VDMA driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff