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linux/drivers/dma/xilinx/xilinx_dpdma.c
Hyun Kwon 7cbb0c63de dmaengine: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver 
The ZynqMP DisplayPort subsystem includes a DMA engine called DPDMA with
6 DMa channels (4 for display and 2 for audio). This driver exposes the
DPDMA through the dmaengine API, to be used by audio (ALSA) and display
(DRM) drivers for the DisplayPort subsystem.

Signed-off-by: Hyun Kwon <hyun.kwon@xilinx.com>
Signed-off-by: Tejas Upadhyay <tejasu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20200717013337.24122-4-laurent.pinchart@ideasonboard.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-07-17 11:37:59 +05:30

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// SPDX-License-Identifier: GPL-2.0
/*
* Xilinx ZynqMP DPDMA Engine driver
*
* Copyright (C) 2015 - 2020 Xilinx, Inc.
*
* Author: Hyun Woo Kwon <hyun.kwon@xilinx.com>
*/
#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <dt-bindings/dma/xlnx-zynqmp-dpdma.h>
#include "../dmaengine.h"
#include "../virt-dma.h"
/* DPDMA registers */
#define XILINX_DPDMA_ERR_CTRL 0x000
#define XILINX_DPDMA_ISR 0x004
#define XILINX_DPDMA_IMR 0x008
#define XILINX_DPDMA_IEN 0x00c
#define XILINX_DPDMA_IDS 0x010
#define XILINX_DPDMA_INTR_DESC_DONE(n) BIT((n) + 0)
#define XILINX_DPDMA_INTR_DESC_DONE_MASK GENMASK(5, 0)
#define XILINX_DPDMA_INTR_NO_OSTAND(n) BIT((n) + 6)
#define XILINX_DPDMA_INTR_NO_OSTAND_MASK GENMASK(11, 6)
#define XILINX_DPDMA_INTR_AXI_ERR(n) BIT((n) + 12)
#define XILINX_DPDMA_INTR_AXI_ERR_MASK GENMASK(17, 12)
#define XILINX_DPDMA_INTR_DESC_ERR(n) BIT((n) + 16)
#define XILINX_DPDMA_INTR_DESC_ERR_MASK GENMASK(23, 18)
#define XILINX_DPDMA_INTR_WR_CMD_FIFO_FULL BIT(24)
#define XILINX_DPDMA_INTR_WR_DATA_FIFO_FULL BIT(25)
#define XILINX_DPDMA_INTR_AXI_4K_CROSS BIT(26)
#define XILINX_DPDMA_INTR_VSYNC BIT(27)
#define XILINX_DPDMA_INTR_CHAN_ERR_MASK 0x00041000
#define XILINX_DPDMA_INTR_CHAN_ERR 0x00fff000
#define XILINX_DPDMA_INTR_GLOBAL_ERR 0x07000000
#define XILINX_DPDMA_INTR_ERR_ALL 0x07fff000
#define XILINX_DPDMA_INTR_CHAN_MASK 0x00041041
#define XILINX_DPDMA_INTR_GLOBAL_MASK 0x0f000000
#define XILINX_DPDMA_INTR_ALL 0x0fffffff
#define XILINX_DPDMA_EISR 0x014
#define XILINX_DPDMA_EIMR 0x018
#define XILINX_DPDMA_EIEN 0x01c
#define XILINX_DPDMA_EIDS 0x020
#define XILINX_DPDMA_EINTR_INV_APB BIT(0)
#define XILINX_DPDMA_EINTR_RD_AXI_ERR(n) BIT((n) + 1)
#define XILINX_DPDMA_EINTR_RD_AXI_ERR_MASK GENMASK(6, 1)
#define XILINX_DPDMA_EINTR_PRE_ERR(n) BIT((n) + 7)
#define XILINX_DPDMA_EINTR_PRE_ERR_MASK GENMASK(12, 7)
#define XILINX_DPDMA_EINTR_CRC_ERR(n) BIT((n) + 13)
#define XILINX_DPDMA_EINTR_CRC_ERR_MASK GENMASK(18, 13)
#define XILINX_DPDMA_EINTR_WR_AXI_ERR(n) BIT((n) + 19)
#define XILINX_DPDMA_EINTR_WR_AXI_ERR_MASK GENMASK(24, 19)
#define XILINX_DPDMA_EINTR_DESC_DONE_ERR(n) BIT((n) + 25)
#define XILINX_DPDMA_EINTR_DESC_DONE_ERR_MASK GENMASK(30, 25)
#define XILINX_DPDMA_EINTR_RD_CMD_FIFO_FULL BIT(32)
#define XILINX_DPDMA_EINTR_CHAN_ERR_MASK 0x02082082
#define XILINX_DPDMA_EINTR_CHAN_ERR 0x7ffffffe
#define XILINX_DPDMA_EINTR_GLOBAL_ERR 0x80000001
#define XILINX_DPDMA_EINTR_ALL 0xffffffff
#define XILINX_DPDMA_CNTL 0x100
#define XILINX_DPDMA_GBL 0x104
#define XILINX_DPDMA_GBL_TRIG_MASK(n) ((n) << 0)
#define XILINX_DPDMA_GBL_RETRIG_MASK(n) ((n) << 6)
#define XILINX_DPDMA_ALC0_CNTL 0x108
#define XILINX_DPDMA_ALC0_STATUS 0x10c
#define XILINX_DPDMA_ALC0_MAX 0x110
#define XILINX_DPDMA_ALC0_MIN 0x114
#define XILINX_DPDMA_ALC0_ACC 0x118
#define XILINX_DPDMA_ALC0_ACC_TRAN 0x11c
#define XILINX_DPDMA_ALC1_CNTL 0x120
#define XILINX_DPDMA_ALC1_STATUS 0x124
#define XILINX_DPDMA_ALC1_MAX 0x128
#define XILINX_DPDMA_ALC1_MIN 0x12c
#define XILINX_DPDMA_ALC1_ACC 0x130
#define XILINX_DPDMA_ALC1_ACC_TRAN 0x134
/* Channel register */
#define XILINX_DPDMA_CH_BASE 0x200
#define XILINX_DPDMA_CH_OFFSET 0x100
#define XILINX_DPDMA_CH_DESC_START_ADDRE 0x000
#define XILINX_DPDMA_CH_DESC_START_ADDRE_MASK GENMASK(15, 0)
#define XILINX_DPDMA_CH_DESC_START_ADDR 0x004
#define XILINX_DPDMA_CH_DESC_NEXT_ADDRE 0x008
#define XILINX_DPDMA_CH_DESC_NEXT_ADDR 0x00c
#define XILINX_DPDMA_CH_PYLD_CUR_ADDRE 0x010
#define XILINX_DPDMA_CH_PYLD_CUR_ADDR 0x014
#define XILINX_DPDMA_CH_CNTL 0x018
#define XILINX_DPDMA_CH_CNTL_ENABLE BIT(0)
#define XILINX_DPDMA_CH_CNTL_PAUSE BIT(1)
#define XILINX_DPDMA_CH_CNTL_QOS_DSCR_WR_MASK GENMASK(5, 2)
#define XILINX_DPDMA_CH_CNTL_QOS_DSCR_RD_MASK GENMASK(9, 6)
#define XILINX_DPDMA_CH_CNTL_QOS_DATA_RD_MASK GENMASK(13, 10)
#define XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS 11
#define XILINX_DPDMA_CH_STATUS 0x01c
#define XILINX_DPDMA_CH_STATUS_OTRAN_CNT_MASK GENMASK(24, 21)
#define XILINX_DPDMA_CH_VDO 0x020
#define XILINX_DPDMA_CH_PYLD_SZ 0x024
#define XILINX_DPDMA_CH_DESC_ID 0x028
/* DPDMA descriptor fields */
#define XILINX_DPDMA_DESC_CONTROL_PREEMBLE 0xa5
#define XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR BIT(8)
#define XILINX_DPDMA_DESC_CONTROL_DESC_UPDATE BIT(9)
#define XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE BIT(10)
#define XILINX_DPDMA_DESC_CONTROL_FRAG_MODE BIT(18)
#define XILINX_DPDMA_DESC_CONTROL_LAST BIT(19)
#define XILINX_DPDMA_DESC_CONTROL_ENABLE_CRC BIT(20)
#define XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME BIT(21)
#define XILINX_DPDMA_DESC_ID_MASK GENMASK(15, 0)
#define XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK GENMASK(17, 0)
#define XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK GENMASK(31, 18)
#define XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK GENMASK(15, 0)
#define XILINX_DPDMA_DESC_ADDR_EXT_SRC_ADDR_MASK GENMASK(31, 16)
#define XILINX_DPDMA_ALIGN_BYTES 256
#define XILINX_DPDMA_LINESIZE_ALIGN_BITS 128
#define XILINX_DPDMA_NUM_CHAN 6
struct xilinx_dpdma_chan;
/**
* struct xilinx_dpdma_hw_desc - DPDMA hardware descriptor
* @control: control configuration field
* @desc_id: descriptor ID
* @xfer_size: transfer size
* @hsize_stride: horizontal size and stride
* @timestamp_lsb: LSB of time stamp
* @timestamp_msb: MSB of time stamp
* @addr_ext: upper 16 bit of 48 bit address (next_desc and src_addr)
* @next_desc: next descriptor 32 bit address
* @src_addr: payload source address (1st page, 32 LSB)
* @addr_ext_23: payload source address (3nd and 3rd pages, 16 LSBs)
* @addr_ext_45: payload source address (4th and 5th pages, 16 LSBs)
* @src_addr2: payload source address (2nd page, 32 LSB)
* @src_addr3: payload source address (3rd page, 32 LSB)
* @src_addr4: payload source address (4th page, 32 LSB)
* @src_addr5: payload source address (5th page, 32 LSB)
* @crc: descriptor CRC
*/
struct xilinx_dpdma_hw_desc {
u32 control;
u32 desc_id;
u32 xfer_size;
u32 hsize_stride;
u32 timestamp_lsb;
u32 timestamp_msb;
u32 addr_ext;
u32 next_desc;
u32 src_addr;
u32 addr_ext_23;
u32 addr_ext_45;
u32 src_addr2;
u32 src_addr3;
u32 src_addr4;
u32 src_addr5;
u32 crc;
} __aligned(XILINX_DPDMA_ALIGN_BYTES);
/**
* struct xilinx_dpdma_sw_desc - DPDMA software descriptor
* @hw: DPDMA hardware descriptor
* @node: list node for software descriptors
* @dma_addr: DMA address of the software descriptor
*/
struct xilinx_dpdma_sw_desc {
struct xilinx_dpdma_hw_desc hw;
struct list_head node;
dma_addr_t dma_addr;
};
/**
* struct xilinx_dpdma_tx_desc - DPDMA transaction descriptor
* @vdesc: virtual DMA descriptor
* @chan: DMA channel
* @descriptors: list of software descriptors
* @error: an error has been detected with this descriptor
*/
struct xilinx_dpdma_tx_desc {
struct virt_dma_desc vdesc;
struct xilinx_dpdma_chan *chan;
struct list_head descriptors;
bool error;
};
#define to_dpdma_tx_desc(_desc) \
container_of(_desc, struct xilinx_dpdma_tx_desc, vdesc)
/**
* struct xilinx_dpdma_chan - DPDMA channel
* @vchan: virtual DMA channel
* @reg: register base address
* @id: channel ID
* @wait_to_stop: queue to wait for outstanding transacitons before stopping
* @running: true if the channel is running
* @first_frame: flag for the first frame of stream
* @video_group: flag if multi-channel operation is needed for video channels
* @lock: lock to access struct xilinx_dpdma_chan
* @desc_pool: descriptor allocation pool
* @err_task: error IRQ bottom half handler
* @desc.pending: Descriptor schedule to the hardware, pending execution
* @desc.active: Descriptor being executed by the hardware
* @xdev: DPDMA device
*/
struct xilinx_dpdma_chan {
struct virt_dma_chan vchan;
void __iomem *reg;
unsigned int id;
wait_queue_head_t wait_to_stop;
bool running;
bool first_frame;
bool video_group;
spinlock_t lock; /* lock to access struct xilinx_dpdma_chan */
struct dma_pool *desc_pool;
struct tasklet_struct err_task;
struct {
struct xilinx_dpdma_tx_desc *pending;
struct xilinx_dpdma_tx_desc *active;
} desc;
struct xilinx_dpdma_device *xdev;
};
#define to_xilinx_chan(_chan) \
container_of(_chan, struct xilinx_dpdma_chan, vchan.chan)
/**
* struct xilinx_dpdma_device - DPDMA device
* @common: generic dma device structure
* @reg: register base address
* @dev: generic device structure
* @irq: the interrupt number
* @axi_clk: axi clock
* @chan: DPDMA channels
* @ext_addr: flag for 64 bit system (48 bit addressing)
*/
struct xilinx_dpdma_device {
struct dma_device common;
void __iomem *reg;
struct device *dev;
int irq;
struct clk *axi_clk;
struct xilinx_dpdma_chan *chan[XILINX_DPDMA_NUM_CHAN];
bool ext_addr;
};
/* -----------------------------------------------------------------------------
* I/O Accessors
*/
static inline u32 dpdma_read(void __iomem *base, u32 offset)
{
return ioread32(base + offset);
}
static inline void dpdma_write(void __iomem *base, u32 offset, u32 val)
{
iowrite32(val, base + offset);
}
static inline void dpdma_clr(void __iomem *base, u32 offset, u32 clr)
{
dpdma_write(base, offset, dpdma_read(base, offset) & ~clr);
}
static inline void dpdma_set(void __iomem *base, u32 offset, u32 set)
{
dpdma_write(base, offset, dpdma_read(base, offset) | set);
}
/* -----------------------------------------------------------------------------
* Descriptor Operations
*/
/**
* xilinx_dpdma_sw_desc_set_dma_addrs - Set DMA addresses in the descriptor
* @sw_desc: The software descriptor in which to set DMA addresses
* @prev: The previous descriptor
* @dma_addr: array of dma addresses
* @num_src_addr: number of addresses in @dma_addr
*
* Set all the DMA addresses in the hardware descriptor corresponding to @dev
* from @dma_addr. If a previous descriptor is specified in @prev, its next
* descriptor DMA address is set to the DMA address of @sw_desc. @prev may be
* identical to @sw_desc for cyclic transfers.
*/
static void xilinx_dpdma_sw_desc_set_dma_addrs(struct xilinx_dpdma_device *xdev,
struct xilinx_dpdma_sw_desc *sw_desc,
struct xilinx_dpdma_sw_desc *prev,
dma_addr_t dma_addr[],
unsigned int num_src_addr)
{
struct xilinx_dpdma_hw_desc *hw_desc = &sw_desc->hw;
unsigned int i;
hw_desc->src_addr = lower_32_bits(dma_addr[0]);
if (xdev->ext_addr)
hw_desc->addr_ext |=
FIELD_PREP(XILINX_DPDMA_DESC_ADDR_EXT_SRC_ADDR_MASK,
upper_32_bits(dma_addr[0]));
for (i = 1; i < num_src_addr; i++) {
u32 *addr = &hw_desc->src_addr2;
addr[i-1] = lower_32_bits(dma_addr[i]);
if (xdev->ext_addr) {
u32 *addr_ext = &hw_desc->addr_ext_23;
u32 addr_msb;
addr_msb = upper_32_bits(dma_addr[i]) & GENMASK(15, 0);
addr_msb <<= 16 * ((i - 1) % 2);
addr_ext[(i - 1) / 2] |= addr_msb;
}
}
if (!prev)
return;
prev->hw.next_desc = lower_32_bits(sw_desc->dma_addr);
if (xdev->ext_addr)
prev->hw.addr_ext |=
FIELD_PREP(XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK,
upper_32_bits(sw_desc->dma_addr));
}
/**
* xilinx_dpdma_chan_alloc_sw_desc - Allocate a software descriptor
* @chan: DPDMA channel
*
* Allocate a software descriptor from the channel's descriptor pool.
*
* Return: a software descriptor or NULL.
*/
static struct xilinx_dpdma_sw_desc *
xilinx_dpdma_chan_alloc_sw_desc(struct xilinx_dpdma_chan *chan)
{
struct xilinx_dpdma_sw_desc *sw_desc;
dma_addr_t dma_addr;
sw_desc = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &dma_addr);
if (!sw_desc)
return NULL;
sw_desc->dma_addr = dma_addr;
return sw_desc;
}
/**
* xilinx_dpdma_chan_free_sw_desc - Free a software descriptor
* @chan: DPDMA channel
* @sw_desc: software descriptor to free
*
* Free a software descriptor from the channel's descriptor pool.
*/
static void
xilinx_dpdma_chan_free_sw_desc(struct xilinx_dpdma_chan *chan,
struct xilinx_dpdma_sw_desc *sw_desc)
{
dma_pool_free(chan->desc_pool, sw_desc, sw_desc->dma_addr);
}
/**
* xilinx_dpdma_chan_dump_tx_desc - Dump a tx descriptor
* @chan: DPDMA channel
* @tx_desc: tx descriptor to dump
*
* Dump contents of a tx descriptor
*/
static void xilinx_dpdma_chan_dump_tx_desc(struct xilinx_dpdma_chan *chan,
struct xilinx_dpdma_tx_desc *tx_desc)
{
struct xilinx_dpdma_sw_desc *sw_desc;
struct device *dev = chan->xdev->dev;
unsigned int i = 0;
dev_dbg(dev, "------- TX descriptor dump start -------\n");
dev_dbg(dev, "------- channel ID = %d -------\n", chan->id);
list_for_each_entry(sw_desc, &tx_desc->descriptors, node) {
struct xilinx_dpdma_hw_desc *hw_desc = &sw_desc->hw;
dev_dbg(dev, "------- HW descriptor %d -------\n", i++);
dev_dbg(dev, "descriptor DMA addr: %pad\n", &sw_desc->dma_addr);
dev_dbg(dev, "control: 0x%08x\n", hw_desc->control);
dev_dbg(dev, "desc_id: 0x%08x\n", hw_desc->desc_id);
dev_dbg(dev, "xfer_size: 0x%08x\n", hw_desc->xfer_size);
dev_dbg(dev, "hsize_stride: 0x%08x\n", hw_desc->hsize_stride);
dev_dbg(dev, "timestamp_lsb: 0x%08x\n", hw_desc->timestamp_lsb);
dev_dbg(dev, "timestamp_msb: 0x%08x\n", hw_desc->timestamp_msb);
dev_dbg(dev, "addr_ext: 0x%08x\n", hw_desc->addr_ext);
dev_dbg(dev, "next_desc: 0x%08x\n", hw_desc->next_desc);
dev_dbg(dev, "src_addr: 0x%08x\n", hw_desc->src_addr);
dev_dbg(dev, "addr_ext_23: 0x%08x\n", hw_desc->addr_ext_23);
dev_dbg(dev, "addr_ext_45: 0x%08x\n", hw_desc->addr_ext_45);
dev_dbg(dev, "src_addr2: 0x%08x\n", hw_desc->src_addr2);
dev_dbg(dev, "src_addr3: 0x%08x\n", hw_desc->src_addr3);
dev_dbg(dev, "src_addr4: 0x%08x\n", hw_desc->src_addr4);
dev_dbg(dev, "src_addr5: 0x%08x\n", hw_desc->src_addr5);
dev_dbg(dev, "crc: 0x%08x\n", hw_desc->crc);
}
dev_dbg(dev, "------- TX descriptor dump end -------\n");
}
/**
* xilinx_dpdma_chan_alloc_tx_desc - Allocate a transaction descriptor
* @chan: DPDMA channel
*
* Allocate a tx descriptor.
*
* Return: a tx descriptor or NULL.
*/
static struct xilinx_dpdma_tx_desc *
xilinx_dpdma_chan_alloc_tx_desc(struct xilinx_dpdma_chan *chan)
{
struct xilinx_dpdma_tx_desc *tx_desc;
tx_desc = kzalloc(sizeof(*tx_desc), GFP_NOWAIT);
if (!tx_desc)
return NULL;
INIT_LIST_HEAD(&tx_desc->descriptors);
tx_desc->chan = chan;
tx_desc->error = false;
return tx_desc;
}
/**
* xilinx_dpdma_chan_free_tx_desc - Free a virtual DMA descriptor
* @vdesc: virtual DMA descriptor
*
* Free the virtual DMA descriptor @vdesc including its software descriptors.
*/
static void xilinx_dpdma_chan_free_tx_desc(struct virt_dma_desc *vdesc)
{
struct xilinx_dpdma_sw_desc *sw_desc, *next;
struct xilinx_dpdma_tx_desc *desc;
if (!vdesc)
return;
desc = to_dpdma_tx_desc(vdesc);
list_for_each_entry_safe(sw_desc, next, &desc->descriptors, node) {
list_del(&sw_desc->node);
xilinx_dpdma_chan_free_sw_desc(desc->chan, sw_desc);
}
kfree(desc);
}
/**
* xilinx_dpdma_chan_prep_interleaved_dma - Prepare an interleaved dma
* descriptor
* @chan: DPDMA channel
* @xt: dma interleaved template
*
* Prepare a tx descriptor including internal software/hardware descriptors
* based on @xt.
*
* Return: A DPDMA TX descriptor on success, or NULL.
*/
static struct xilinx_dpdma_tx_desc *
xilinx_dpdma_chan_prep_interleaved_dma(struct xilinx_dpdma_chan *chan,
struct dma_interleaved_template *xt)
{
struct xilinx_dpdma_tx_desc *tx_desc;
struct xilinx_dpdma_sw_desc *sw_desc;
struct xilinx_dpdma_hw_desc *hw_desc;
size_t hsize = xt->sgl[0].size;
size_t stride = hsize + xt->sgl[0].icg;
if (!IS_ALIGNED(xt->src_start, XILINX_DPDMA_ALIGN_BYTES)) {
dev_err(chan->xdev->dev, "buffer should be aligned at %d B\n",
XILINX_DPDMA_ALIGN_BYTES);
return NULL;
}
tx_desc = xilinx_dpdma_chan_alloc_tx_desc(chan);
if (!tx_desc)
return NULL;
sw_desc = xilinx_dpdma_chan_alloc_sw_desc(chan);
if (!sw_desc) {
xilinx_dpdma_chan_free_tx_desc(&tx_desc->vdesc);
return NULL;
}
xilinx_dpdma_sw_desc_set_dma_addrs(chan->xdev, sw_desc, sw_desc,
&xt->src_start, 1);
hw_desc = &sw_desc->hw;
hsize = ALIGN(hsize, XILINX_DPDMA_LINESIZE_ALIGN_BITS / 8);
hw_desc->xfer_size = hsize * xt->numf;
hw_desc->hsize_stride =
FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK, hsize) |
FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK,
stride / 16);
hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_PREEMBLE;
hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR;
hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE;
hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME;
list_add_tail(&sw_desc->node, &tx_desc->descriptors);
return tx_desc;
}
/* -----------------------------------------------------------------------------
* DPDMA Channel Operations
*/
/**
* xilinx_dpdma_chan_enable - Enable the channel
* @chan: DPDMA channel
*
* Enable the channel and its interrupts. Set the QoS values for video class.
*/
static void xilinx_dpdma_chan_enable(struct xilinx_dpdma_chan *chan)
{
u32 reg;
reg = (XILINX_DPDMA_INTR_CHAN_MASK << chan->id)
| XILINX_DPDMA_INTR_GLOBAL_MASK;
dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN, reg);
reg = (XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id)
| XILINX_DPDMA_INTR_GLOBAL_ERR;
dpdma_write(chan->xdev->reg, XILINX_DPDMA_EIEN, reg);
reg = XILINX_DPDMA_CH_CNTL_ENABLE
| FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DSCR_WR_MASK,
XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS)
| FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DSCR_RD_MASK,
XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS)
| FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DATA_RD_MASK,
XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS);
dpdma_set(chan->reg, XILINX_DPDMA_CH_CNTL, reg);
}
/**
* xilinx_dpdma_chan_disable - Disable the channel
* @chan: DPDMA channel
*
* Disable the channel and its interrupts.
*/
static void xilinx_dpdma_chan_disable(struct xilinx_dpdma_chan *chan)
{
u32 reg;
reg = XILINX_DPDMA_INTR_CHAN_MASK << chan->id;
dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN, reg);
reg = XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id;
dpdma_write(chan->xdev->reg, XILINX_DPDMA_EIEN, reg);
dpdma_clr(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_ENABLE);
}
/**
* xilinx_dpdma_chan_pause - Pause the channel
* @chan: DPDMA channel
*
* Pause the channel.
*/
static void xilinx_dpdma_chan_pause(struct xilinx_dpdma_chan *chan)
{
dpdma_set(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_PAUSE);
}
/**
* xilinx_dpdma_chan_unpause - Unpause the channel
* @chan: DPDMA channel
*
* Unpause the channel.
*/
static void xilinx_dpdma_chan_unpause(struct xilinx_dpdma_chan *chan)
{
dpdma_clr(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_PAUSE);
}
static u32 xilinx_dpdma_chan_video_group_ready(struct xilinx_dpdma_chan *chan)
{
struct xilinx_dpdma_device *xdev = chan->xdev;
u32 channels = 0;
unsigned int i;
for (i = ZYNQMP_DPDMA_VIDEO0; i <= ZYNQMP_DPDMA_VIDEO2; i++) {
if (xdev->chan[i]->video_group && !xdev->chan[i]->running)
return 0;
if (xdev->chan[i]->video_group)
channels |= BIT(i);
}
return channels;
}
/**
* xilinx_dpdma_chan_queue_transfer - Queue the next transfer
* @chan: DPDMA channel
*
* Queue the next descriptor, if any, to the hardware. If the channel is
* stopped, start it first. Otherwise retrigger it with the next descriptor.
*/
static void xilinx_dpdma_chan_queue_transfer(struct xilinx_dpdma_chan *chan)
{
struct xilinx_dpdma_device *xdev = chan->xdev;
struct xilinx_dpdma_sw_desc *sw_desc;
struct xilinx_dpdma_tx_desc *desc;
struct virt_dma_desc *vdesc;
u32 reg, channels;
lockdep_assert_held(&chan->lock);
if (chan->desc.pending)
return;
if (!chan->running) {
xilinx_dpdma_chan_unpause(chan);
xilinx_dpdma_chan_enable(chan);
chan->first_frame = true;
chan->running = true;
}
if (chan->video_group)
channels = xilinx_dpdma_chan_video_group_ready(chan);
else
channels = BIT(chan->id);
if (!channels)
return;
vdesc = vchan_next_desc(&chan->vchan);
if (!vdesc)
return;
desc = to_dpdma_tx_desc(vdesc);
chan->desc.pending = desc;
list_del(&desc->vdesc.node);
/*
* Assign the cookie to descriptors in this transaction. Only 16 bit
* will be used, but it should be enough.
*/
list_for_each_entry(sw_desc, &desc->descriptors, node)
sw_desc->hw.desc_id = desc->vdesc.tx.cookie;
sw_desc = list_first_entry(&desc->descriptors,
struct xilinx_dpdma_sw_desc, node);
dpdma_write(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDR,
lower_32_bits(sw_desc->dma_addr));
if (xdev->ext_addr)
dpdma_write(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDRE,
FIELD_PREP(XILINX_DPDMA_CH_DESC_START_ADDRE_MASK,
upper_32_bits(sw_desc->dma_addr)));
if (chan->first_frame)
reg = XILINX_DPDMA_GBL_TRIG_MASK(channels);
else
reg = XILINX_DPDMA_GBL_RETRIG_MASK(channels);
chan->first_frame = false;
dpdma_write(xdev->reg, XILINX_DPDMA_GBL, reg);
}
/**
* xilinx_dpdma_chan_ostand - Number of outstanding transactions
* @chan: DPDMA channel
*
* Read and return the number of outstanding transactions from register.
*
* Return: Number of outstanding transactions from the status register.
*/
static u32 xilinx_dpdma_chan_ostand(struct xilinx_dpdma_chan *chan)
{
return FIELD_GET(XILINX_DPDMA_CH_STATUS_OTRAN_CNT_MASK,
dpdma_read(chan->reg, XILINX_DPDMA_CH_STATUS));
}
/**
* xilinx_dpdma_chan_no_ostand - Notify no outstanding transaction event
* @chan: DPDMA channel
*
* Notify waiters for no outstanding event, so waiters can stop the channel
* safely. This function is supposed to be called when 'no outstanding'
* interrupt is generated. The 'no outstanding' interrupt is disabled and
* should be re-enabled when this event is handled. If the channel status
* register still shows some number of outstanding transactions, the interrupt
* remains enabled.
*
* Return: 0 on success. On failure, -EWOULDBLOCK if there's still outstanding
* transaction(s).
*/
static int xilinx_dpdma_chan_notify_no_ostand(struct xilinx_dpdma_chan *chan)
{
u32 cnt;
cnt = xilinx_dpdma_chan_ostand(chan);
if (cnt) {
dev_dbg(chan->xdev->dev, "%d outstanding transactions\n", cnt);
return -EWOULDBLOCK;
}
/* Disable 'no outstanding' interrupt */
dpdma_write(chan->xdev->reg, XILINX_DPDMA_IDS,
XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
wake_up(&chan->wait_to_stop);
return 0;
}
/**
* xilinx_dpdma_chan_wait_no_ostand - Wait for the no outstanding irq
* @chan: DPDMA channel
*
* Wait for the no outstanding transaction interrupt. This functions can sleep
* for 50ms.
*
* Return: 0 on success. On failure, -ETIMEOUT for time out, or the error code
* from wait_event_interruptible_timeout().
*/
static int xilinx_dpdma_chan_wait_no_ostand(struct xilinx_dpdma_chan *chan)
{
int ret;
/* Wait for a no outstanding transaction interrupt upto 50msec */
ret = wait_event_interruptible_timeout(chan->wait_to_stop,
!xilinx_dpdma_chan_ostand(chan),
msecs_to_jiffies(50));
if (ret > 0) {
dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN,
XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
return 0;
}
dev_err(chan->xdev->dev, "not ready to stop: %d trans\n",
xilinx_dpdma_chan_ostand(chan));
if (ret == 0)
return -ETIMEDOUT;
return ret;
}
/**
* xilinx_dpdma_chan_poll_no_ostand - Poll the outstanding transaction status
* @chan: DPDMA channel
*
* Poll the outstanding transaction status, and return when there's no
* outstanding transaction. This functions can be used in the interrupt context
* or where the atomicity is required. Calling thread may wait more than 50ms.
*
* Return: 0 on success, or -ETIMEDOUT.
*/
static int xilinx_dpdma_chan_poll_no_ostand(struct xilinx_dpdma_chan *chan)
{
u32 cnt, loop = 50000;
/* Poll at least for 50ms (20 fps). */
do {
cnt = xilinx_dpdma_chan_ostand(chan);
udelay(1);
} while (loop-- > 0 && cnt);
if (loop) {
dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN,
XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
return 0;
}
dev_err(chan->xdev->dev, "not ready to stop: %d trans\n",
xilinx_dpdma_chan_ostand(chan));
return -ETIMEDOUT;
}
/**
* xilinx_dpdma_chan_stop - Stop the channel
* @chan: DPDMA channel
*
* Stop a previously paused channel by first waiting for completion of all
* outstanding transaction and then disabling the channel.
*
* Return: 0 on success, or -ETIMEDOUT if the channel failed to stop.
*/
static int xilinx_dpdma_chan_stop(struct xilinx_dpdma_chan *chan)
{
unsigned long flags;
int ret;
ret = xilinx_dpdma_chan_wait_no_ostand(chan);
if (ret)
return ret;
spin_lock_irqsave(&chan->lock, flags);
xilinx_dpdma_chan_disable(chan);
chan->running = false;
spin_unlock_irqrestore(&chan->lock, flags);
return 0;
}
/**
* xilinx_dpdma_chan_done_irq - Handle hardware descriptor completion
* @chan: DPDMA channel
*
* Handle completion of the currently active descriptor (@chan->desc.active). As
* we currently support cyclic transfers only, this just invokes the cyclic
* callback. The descriptor will be completed at the VSYNC interrupt when a new
* descriptor replaces it.
*/
static void xilinx_dpdma_chan_done_irq(struct xilinx_dpdma_chan *chan)
{
struct xilinx_dpdma_tx_desc *active = chan->desc.active;
unsigned long flags;
spin_lock_irqsave(&chan->lock, flags);
if (active)
vchan_cyclic_callback(&active->vdesc);
else
dev_warn(chan->xdev->dev,
"DONE IRQ with no active descriptor!\n");
spin_unlock_irqrestore(&chan->lock, flags);
}
/**
* xilinx_dpdma_chan_vsync_irq - Handle hardware descriptor scheduling
* @chan: DPDMA channel
*
* At VSYNC the active descriptor may have been replaced by the pending
* descriptor. Detect this through the DESC_ID and perform appropriate
* bookkeeping.
*/
static void xilinx_dpdma_chan_vsync_irq(struct xilinx_dpdma_chan *chan)
{
struct xilinx_dpdma_tx_desc *pending;
struct xilinx_dpdma_sw_desc *sw_desc;
unsigned long flags;
u32 desc_id;
spin_lock_irqsave(&chan->lock, flags);
pending = chan->desc.pending;
if (!chan->running || !pending)
goto out;
desc_id = dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_ID);
/* If the retrigger raced with vsync, retry at the next frame. */
sw_desc = list_first_entry(&pending->descriptors,
struct xilinx_dpdma_sw_desc, node);
if (sw_desc->hw.desc_id != desc_id)
goto out;
/*
* Complete the active descriptor, if any, promote the pending
* descriptor to active, and queue the next transfer, if any.
*/
if (chan->desc.active)
vchan_cookie_complete(&chan->desc.active->vdesc);
chan->desc.active = pending;
chan->desc.pending = NULL;
xilinx_dpdma_chan_queue_transfer(chan);
out:
spin_unlock_irqrestore(&chan->lock, flags);
}
/**
* xilinx_dpdma_chan_err - Detect any channel error
* @chan: DPDMA channel
* @isr: masked Interrupt Status Register
* @eisr: Error Interrupt Status Register
*
* Return: true if any channel error occurs, or false otherwise.
*/
static bool
xilinx_dpdma_chan_err(struct xilinx_dpdma_chan *chan, u32 isr, u32 eisr)
{
if (!chan)
return false;
if (chan->running &&
((isr & (XILINX_DPDMA_INTR_CHAN_ERR_MASK << chan->id)) ||
(eisr & (XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id))))
return true;
return false;
}
/**
* xilinx_dpdma_chan_handle_err - DPDMA channel error handling
* @chan: DPDMA channel
*
* This function is called when any channel error or any global error occurs.
* The function disables the paused channel by errors and determines
* if the current active descriptor can be rescheduled depending on
* the descriptor status.
*/
static void xilinx_dpdma_chan_handle_err(struct xilinx_dpdma_chan *chan)
{
struct xilinx_dpdma_device *xdev = chan->xdev;
struct xilinx_dpdma_tx_desc *active;
unsigned long flags;
spin_lock_irqsave(&chan->lock, flags);
dev_dbg(xdev->dev, "cur desc addr = 0x%04x%08x\n",
dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDRE),
dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDR));
dev_dbg(xdev->dev, "cur payload addr = 0x%04x%08x\n",
dpdma_read(chan->reg, XILINX_DPDMA_CH_PYLD_CUR_ADDRE),
dpdma_read(chan->reg, XILINX_DPDMA_CH_PYLD_CUR_ADDR));
xilinx_dpdma_chan_disable(chan);
chan->running = false;
if (!chan->desc.active)
goto out_unlock;
active = chan->desc.active;
chan->desc.active = NULL;
xilinx_dpdma_chan_dump_tx_desc(chan, active);
if (active->error)
dev_dbg(xdev->dev, "repeated error on desc\n");
/* Reschedule if there's no new descriptor */
if (!chan->desc.pending &&
list_empty(&chan->vchan.desc_issued)) {
active->error = true;
list_add_tail(&active->vdesc.node,
&chan->vchan.desc_issued);
} else {
xilinx_dpdma_chan_free_tx_desc(&active->vdesc);
}
out_unlock:
spin_unlock_irqrestore(&chan->lock, flags);
}
/* -----------------------------------------------------------------------------
* DMA Engine Operations
*/
static struct dma_async_tx_descriptor *
xilinx_dpdma_prep_interleaved_dma(struct dma_chan *dchan,
struct dma_interleaved_template *xt,
unsigned long flags)
{
struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
struct xilinx_dpdma_tx_desc *desc;
if (xt->dir != DMA_MEM_TO_DEV)
return NULL;
if (!xt->numf || !xt->sgl[0].size)
return NULL;
if (!(flags & DMA_PREP_REPEAT) || !(flags & DMA_PREP_LOAD_EOT))
return NULL;
desc = xilinx_dpdma_chan_prep_interleaved_dma(chan, xt);
if (!desc)
return NULL;
vchan_tx_prep(&chan->vchan, &desc->vdesc, flags | DMA_CTRL_ACK);
return &desc->vdesc.tx;
}
/**
* xilinx_dpdma_alloc_chan_resources - Allocate resources for the channel
* @dchan: DMA channel
*
* Allocate a descriptor pool for the channel.
*
* Return: 0 on success, or -ENOMEM if failed to allocate a pool.
*/
static int xilinx_dpdma_alloc_chan_resources(struct dma_chan *dchan)
{
struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
size_t align = __alignof__(struct xilinx_dpdma_sw_desc);
chan->desc_pool = dma_pool_create(dev_name(chan->xdev->dev),
chan->xdev->dev,
sizeof(struct xilinx_dpdma_sw_desc),
align, 0);
if (!chan->desc_pool) {
dev_err(chan->xdev->dev,
"failed to allocate a descriptor pool\n");
return -ENOMEM;
}
return 0;
}
/**
* xilinx_dpdma_free_chan_resources - Free all resources for the channel
* @dchan: DMA channel
*
* Free resources associated with the virtual DMA channel, and destroy the
* descriptor pool.
*/
static void xilinx_dpdma_free_chan_resources(struct dma_chan *dchan)
{
struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
vchan_free_chan_resources(&chan->vchan);
dma_pool_destroy(chan->desc_pool);
chan->desc_pool = NULL;
}
static void xilinx_dpdma_issue_pending(struct dma_chan *dchan)
{
struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
unsigned long flags;
spin_lock_irqsave(&chan->vchan.lock, flags);
if (vchan_issue_pending(&chan->vchan))
xilinx_dpdma_chan_queue_transfer(chan);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
}
static int xilinx_dpdma_config(struct dma_chan *dchan,
struct dma_slave_config *config)
{
struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
unsigned long flags;
/*
* The destination address doesn't need to be specified as the DPDMA is
* hardwired to the destination (the DP controller). The transfer
* width, burst size and port window size are thus meaningless, they're
* fixed both on the DPDMA side and on the DP controller side.
*/
spin_lock_irqsave(&chan->lock, flags);
/*
* Abuse the slave_id to indicate that the channel is part of a video
* group.
*/
if (chan->id >= ZYNQMP_DPDMA_VIDEO0 && chan->id <= ZYNQMP_DPDMA_VIDEO2)
chan->video_group = config->slave_id != 0;
spin_unlock_irqrestore(&chan->lock, flags);
return 0;
}
static int xilinx_dpdma_pause(struct dma_chan *dchan)
{
xilinx_dpdma_chan_pause(to_xilinx_chan(dchan));
return 0;
}
static int xilinx_dpdma_resume(struct dma_chan *dchan)
{
xilinx_dpdma_chan_unpause(to_xilinx_chan(dchan));
return 0;
}
/**
* xilinx_dpdma_terminate_all - Terminate the channel and descriptors
* @dchan: DMA channel
*
* Pause the channel without waiting for ongoing transfers to complete. Waiting
* for completion is performed by xilinx_dpdma_synchronize() that will disable
* the channel to complete the stop.
*
* All the descriptors associated with the channel that are guaranteed not to
* be touched by the hardware. The pending and active descriptor are not
* touched, and will be freed either upon completion, or by
* xilinx_dpdma_synchronize().
*
* Return: 0 on success, or -ETIMEDOUT if the channel failed to stop.
*/
static int xilinx_dpdma_terminate_all(struct dma_chan *dchan)
{
struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
struct xilinx_dpdma_device *xdev = chan->xdev;
LIST_HEAD(descriptors);
unsigned long flags;
unsigned int i;
/* Pause the channel (including the whole video group if applicable). */
if (chan->video_group) {
for (i = ZYNQMP_DPDMA_VIDEO0; i <= ZYNQMP_DPDMA_VIDEO2; i++) {
if (xdev->chan[i]->video_group &&
xdev->chan[i]->running) {
xilinx_dpdma_chan_pause(xdev->chan[i]);
xdev->chan[i]->video_group = false;
}
}
} else {
xilinx_dpdma_chan_pause(chan);
}
/* Gather all the descriptors we can free and free them. */
spin_lock_irqsave(&chan->vchan.lock, flags);
vchan_get_all_descriptors(&chan->vchan, &descriptors);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
vchan_dma_desc_free_list(&chan->vchan, &descriptors);
return 0;
}
/**
* xilinx_dpdma_synchronize - Synchronize callback execution
* @dchan: DMA channel
*
* Synchronizing callback execution ensures that all previously issued
* transfers have completed and all associated callbacks have been called and
* have returned.
*
* This function waits for the DMA channel to stop. It assumes it has been
* paused by a previous call to dmaengine_terminate_async(), and that no new
* pending descriptors have been issued with dma_async_issue_pending(). The
* behaviour is undefined otherwise.
*/
static void xilinx_dpdma_synchronize(struct dma_chan *dchan)
{
struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
unsigned long flags;
xilinx_dpdma_chan_stop(chan);
spin_lock_irqsave(&chan->vchan.lock, flags);
if (chan->desc.pending) {
vchan_terminate_vdesc(&chan->desc.pending->vdesc);
chan->desc.pending = NULL;
}
if (chan->desc.active) {
vchan_terminate_vdesc(&chan->desc.active->vdesc);
chan->desc.active = NULL;
}
spin_unlock_irqrestore(&chan->vchan.lock, flags);
vchan_synchronize(&chan->vchan);
}
/* -----------------------------------------------------------------------------
* Interrupt and Tasklet Handling
*/
/**
* xilinx_dpdma_err - Detect any global error
* @isr: Interrupt Status Register
* @eisr: Error Interrupt Status Register
*
* Return: True if any global error occurs, or false otherwise.
*/
static bool xilinx_dpdma_err(u32 isr, u32 eisr)
{
if (isr & XILINX_DPDMA_INTR_GLOBAL_ERR ||
eisr & XILINX_DPDMA_EINTR_GLOBAL_ERR)
return true;
return false;
}
/**
* xilinx_dpdma_handle_err_irq - Handle DPDMA error interrupt
* @xdev: DPDMA device
* @isr: masked Interrupt Status Register
* @eisr: Error Interrupt Status Register
*
* Handle if any error occurs based on @isr and @eisr. This function disables
* corresponding error interrupts, and those should be re-enabled once handling
* is done.
*/
static void xilinx_dpdma_handle_err_irq(struct xilinx_dpdma_device *xdev,
u32 isr, u32 eisr)
{
bool err = xilinx_dpdma_err(isr, eisr);
unsigned int i;
dev_dbg_ratelimited(xdev->dev,
"error irq: isr = 0x%08x, eisr = 0x%08x\n",
isr, eisr);
/* Disable channel error interrupts until errors are handled. */
dpdma_write(xdev->reg, XILINX_DPDMA_IDS,
isr & ~XILINX_DPDMA_INTR_GLOBAL_ERR);
dpdma_write(xdev->reg, XILINX_DPDMA_EIDS,
eisr & ~XILINX_DPDMA_EINTR_GLOBAL_ERR);
for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
if (err || xilinx_dpdma_chan_err(xdev->chan[i], isr, eisr))
tasklet_schedule(&xdev->chan[i]->err_task);
}
/**
* xilinx_dpdma_enable_irq - Enable interrupts
* @xdev: DPDMA device
*
* Enable interrupts.
*/
static void xilinx_dpdma_enable_irq(struct xilinx_dpdma_device *xdev)
{
dpdma_write(xdev->reg, XILINX_DPDMA_IEN, XILINX_DPDMA_INTR_ALL);
dpdma_write(xdev->reg, XILINX_DPDMA_EIEN, XILINX_DPDMA_EINTR_ALL);
}
/**
* xilinx_dpdma_disable_irq - Disable interrupts
* @xdev: DPDMA device
*
* Disable interrupts.
*/
static void xilinx_dpdma_disable_irq(struct xilinx_dpdma_device *xdev)
{
dpdma_write(xdev->reg, XILINX_DPDMA_IDS, XILINX_DPDMA_INTR_ERR_ALL);
dpdma_write(xdev->reg, XILINX_DPDMA_EIDS, XILINX_DPDMA_EINTR_ALL);
}
/**
* xilinx_dpdma_chan_err_task - Per channel tasklet for error handling
* @data: tasklet data to be casted to DPDMA channel structure
*
* Per channel error handling tasklet. This function waits for the outstanding
* transaction to complete and triggers error handling. After error handling,
* re-enable channel error interrupts, and restart the channel if needed.
*/
static void xilinx_dpdma_chan_err_task(unsigned long data)
{
struct xilinx_dpdma_chan *chan = (struct xilinx_dpdma_chan *)data;
struct xilinx_dpdma_device *xdev = chan->xdev;
unsigned long flags;
/* Proceed error handling even when polling fails. */
xilinx_dpdma_chan_poll_no_ostand(chan);
xilinx_dpdma_chan_handle_err(chan);
dpdma_write(xdev->reg, XILINX_DPDMA_IEN,
XILINX_DPDMA_INTR_CHAN_ERR_MASK << chan->id);
dpdma_write(xdev->reg, XILINX_DPDMA_EIEN,
XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id);
spin_lock_irqsave(&chan->lock, flags);
xilinx_dpdma_chan_queue_transfer(chan);
spin_unlock_irqrestore(&chan->lock, flags);
}
static irqreturn_t xilinx_dpdma_irq_handler(int irq, void *data)
{
struct xilinx_dpdma_device *xdev = data;
unsigned long mask;
unsigned int i;
u32 status;
u32 error;
status = dpdma_read(xdev->reg, XILINX_DPDMA_ISR);
error = dpdma_read(xdev->reg, XILINX_DPDMA_EISR);
if (!status && !error)
return IRQ_NONE;
dpdma_write(xdev->reg, XILINX_DPDMA_ISR, status);
dpdma_write(xdev->reg, XILINX_DPDMA_EISR, error);
if (status & XILINX_DPDMA_INTR_VSYNC) {
/*
* There's a single VSYNC interrupt that needs to be processed
* by each running channel to update the active descriptor.
*/
for (i = 0; i < ARRAY_SIZE(xdev->chan); i++) {
struct xilinx_dpdma_chan *chan = xdev->chan[i];
if (chan)
xilinx_dpdma_chan_vsync_irq(chan);
}
}
mask = FIELD_GET(XILINX_DPDMA_INTR_DESC_DONE_MASK, status);
if (mask) {
for_each_set_bit(i, &mask, ARRAY_SIZE(xdev->chan))
xilinx_dpdma_chan_done_irq(xdev->chan[i]);
}
mask = FIELD_GET(XILINX_DPDMA_INTR_NO_OSTAND_MASK, status);
if (mask) {
for_each_set_bit(i, &mask, ARRAY_SIZE(xdev->chan))
xilinx_dpdma_chan_notify_no_ostand(xdev->chan[i]);
}
mask = status & XILINX_DPDMA_INTR_ERR_ALL;
if (mask || error)
xilinx_dpdma_handle_err_irq(xdev, mask, error);
return IRQ_HANDLED;
}
/* -----------------------------------------------------------------------------
* Initialization & Cleanup
*/
static int xilinx_dpdma_chan_init(struct xilinx_dpdma_device *xdev,
unsigned int chan_id)
{
struct xilinx_dpdma_chan *chan;
chan = devm_kzalloc(xdev->dev, sizeof(*chan), GFP_KERNEL);
if (!chan)
return -ENOMEM;
chan->id = chan_id;
chan->reg = xdev->reg + XILINX_DPDMA_CH_BASE
+ XILINX_DPDMA_CH_OFFSET * chan->id;
chan->running = false;
chan->xdev = xdev;
spin_lock_init(&chan->lock);
init_waitqueue_head(&chan->wait_to_stop);
tasklet_init(&chan->err_task, xilinx_dpdma_chan_err_task,
(unsigned long)chan);
chan->vchan.desc_free = xilinx_dpdma_chan_free_tx_desc;
vchan_init(&chan->vchan, &xdev->common);
xdev->chan[chan->id] = chan;
return 0;
}
static void xilinx_dpdma_chan_remove(struct xilinx_dpdma_chan *chan)
{
if (!chan)
return;
tasklet_kill(&chan->err_task);
list_del(&chan->vchan.chan.device_node);
}
static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct xilinx_dpdma_device *xdev = ofdma->of_dma_data;
uint32_t chan_id = dma_spec->args[0];
if (chan_id >= ARRAY_SIZE(xdev->chan))
return NULL;
if (!xdev->chan[chan_id])
return NULL;
return dma_get_slave_channel(&xdev->chan[chan_id]->vchan.chan);
}
static int xilinx_dpdma_probe(struct platform_device *pdev)
{
struct xilinx_dpdma_device *xdev;
struct dma_device *ddev;
unsigned int i;
int ret;
xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
if (!xdev)
return -ENOMEM;
xdev->dev = &pdev->dev;
xdev->ext_addr = sizeof(dma_addr_t) > 4;
INIT_LIST_HEAD(&xdev->common.channels);
platform_set_drvdata(pdev, xdev);
xdev->axi_clk = devm_clk_get(xdev->dev, "axi_clk");
if (IS_ERR(xdev->axi_clk))
return PTR_ERR(xdev->axi_clk);
xdev->reg = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(xdev->reg))
return PTR_ERR(xdev->reg);
xdev->irq = platform_get_irq(pdev, 0);
if (xdev->irq < 0) {
dev_err(xdev->dev, "failed to get platform irq\n");
return xdev->irq;
}
ret = request_irq(xdev->irq, xilinx_dpdma_irq_handler, IRQF_SHARED,
dev_name(xdev->dev), xdev);
if (ret) {
dev_err(xdev->dev, "failed to request IRQ\n");
return ret;
}
ddev = &xdev->common;
ddev->dev = &pdev->dev;
dma_cap_set(DMA_SLAVE, ddev->cap_mask);
dma_cap_set(DMA_PRIVATE, ddev->cap_mask);
dma_cap_set(DMA_INTERLEAVE, ddev->cap_mask);
dma_cap_set(DMA_REPEAT, ddev->cap_mask);
dma_cap_set(DMA_LOAD_EOT, ddev->cap_mask);
ddev->copy_align = fls(XILINX_DPDMA_ALIGN_BYTES - 1);
ddev->device_alloc_chan_resources = xilinx_dpdma_alloc_chan_resources;
ddev->device_free_chan_resources = xilinx_dpdma_free_chan_resources;
ddev->device_prep_interleaved_dma = xilinx_dpdma_prep_interleaved_dma;
/* TODO: Can we achieve better granularity ? */
ddev->device_tx_status = dma_cookie_status;
ddev->device_issue_pending = xilinx_dpdma_issue_pending;
ddev->device_config = xilinx_dpdma_config;
ddev->device_pause = xilinx_dpdma_pause;
ddev->device_resume = xilinx_dpdma_resume;
ddev->device_terminate_all = xilinx_dpdma_terminate_all;
ddev->device_synchronize = xilinx_dpdma_synchronize;
ddev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED);
ddev->directions = BIT(DMA_MEM_TO_DEV);
ddev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
for (i = 0; i < ARRAY_SIZE(xdev->chan); ++i) {
ret = xilinx_dpdma_chan_init(xdev, i);
if (ret < 0) {
dev_err(xdev->dev, "failed to initialize channel %u\n",
i);
goto error;
}
}
ret = clk_prepare_enable(xdev->axi_clk);
if (ret) {
dev_err(xdev->dev, "failed to enable the axi clock\n");
goto error;
}
ret = dma_async_device_register(ddev);
if (ret) {
dev_err(xdev->dev, "failed to register the dma device\n");
goto error_dma_async;
}
ret = of_dma_controller_register(xdev->dev->of_node,
of_dma_xilinx_xlate, ddev);
if (ret) {
dev_err(xdev->dev, "failed to register DMA to DT DMA helper\n");
goto error_of_dma;
}
xilinx_dpdma_enable_irq(xdev);
dev_info(&pdev->dev, "Xilinx DPDMA engine is probed\n");
return 0;
error_of_dma:
dma_async_device_unregister(ddev);
error_dma_async:
clk_disable_unprepare(xdev->axi_clk);
error:
for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
xilinx_dpdma_chan_remove(xdev->chan[i]);
free_irq(xdev->irq, xdev);
return ret;
}
static int xilinx_dpdma_remove(struct platform_device *pdev)
{
struct xilinx_dpdma_device *xdev = platform_get_drvdata(pdev);
unsigned int i;
/* Start by disabling the IRQ to avoid races during cleanup. */
free_irq(xdev->irq, xdev);
xilinx_dpdma_disable_irq(xdev);
of_dma_controller_free(pdev->dev.of_node);
dma_async_device_unregister(&xdev->common);
clk_disable_unprepare(xdev->axi_clk);
for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
xilinx_dpdma_chan_remove(xdev->chan[i]);
return 0;
}
static const struct of_device_id xilinx_dpdma_of_match[] = {
{ .compatible = "xlnx,zynqmp-dpdma",},
{ /* end of table */ },
};
MODULE_DEVICE_TABLE(of, xilinx_dpdma_of_match);
static struct platform_driver xilinx_dpdma_driver = {
.probe = xilinx_dpdma_probe,
.remove = xilinx_dpdma_remove,
.driver = {
.name = "xilinx-zynqmp-dpdma",
.of_match_table = xilinx_dpdma_of_match,
},
};
module_platform_driver(xilinx_dpdma_driver);
MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("Xilinx ZynqMP DPDMA driver");
MODULE_LICENSE("GPL v2");
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