[PATCH v4 4/6] dmaengine: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver

Laurent Pinchart
2020-05-13T17:00:07Z

From: Hyun Kwon <hyun.kwon@xilinx.com>

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>
---
Changes since v3:

- Fix uninitialized variable in xilinx_dpdma_config()
- Free pending and active descriptors upon termination
- Switch to DMA_PREP_REPEAT

Changes since v2:

- Switch to virt-dma
- Support interleaved cyclic transfers and nothing else
- Fix terminate_all behaviour (don't wait)
- Fix bug in extended address handling for hw desc
- Clean up video group handling
- Update driver name
- Use macros for bitfields
- Remove unneeded header
- Coding style and typo fixes

Changes since v1:

- Remove unneeded #include
- Drop enum xilinx_dpdma_chan_id
- Update compatible string
- Drop DT subnodes
- Replace XILINX_DPDMA_NUM_CHAN with ARRAY_SIZE(xdev->chan)
- Disable IRQ at remove() time
- Use devm_platform_ioremap_resource()
- Don't inline functions manually
- Add section headers
- Merge DMA engine implementation in their wrappers
- Rename xilinx_dpdma_sw_desc::phys to dma_addr
- Use GENMASK()
- Use FIELD_PREP/FIELD_GET
- Fix MSB handling in xilinx_dpdma_sw_desc_addr_64()
- Fix logic in xilinx_dpdma_chan_prep_slave_sg()
- Document why xilinx_dpdma_config() doesn't need to check most
parameters
- Remove debugfs support
- Rechedule errored descriptor
- Align the line size with 128bit
- SPDX header formatting
---
MAINTAINERS | 1 +
drivers/dma/Kconfig | 10 +
drivers/dma/xilinx/Makefile | 1 +
drivers/dma/xilinx/xilinx_dpdma.c | 1543 +++++++++++++++++++++++++++++
4 files changed, 1555 insertions(+)
create mode 100644 drivers/dma/xilinx/xilinx_dpdma.c

diff --git a/MAINTAINERS b/MAINTAINERS
index be39aab8b706..aae90caba2a6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18435,6 +18435,7 @@ M: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
L: dmaengine@vger.kernel.org
S: Supported
F: Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dpdma.yaml
+F: drivers/dma/xilinx/xilinx_dpdma.c
F: include/dt-bindings/dma/xlnx-zynqmp-dpdma.h

XILLYBUS DRIVER
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 5142da401db3..b8f9d6ba7bf2 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -697,6 +697,16 @@ config XILINX_ZYNQMP_DMA
help
Enable support for Xilinx ZynqMP DMA controller.

+config XILINX_ZYNQMP_DPDMA
+ tristate "Xilinx DPDMA Engine"
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+ help
+ Enable support for Xilinx ZynqMP DisplayPort DMA. Choose this option
+ if you have a Xilinx ZynqMP SoC with a DisplayPort subsystem. The
+ driver provides the dmaengine required by the DisplayPort subsystem
+ display driver.
+
config ZX_DMA
tristate "ZTE ZX DMA support"
depends on ARCH_ZX || COMPILE_TEST
diff --git a/drivers/dma/xilinx/Makefile b/drivers/dma/xilinx/Makefile
index e921de575b55..767bb45f641f 100644
--- a/drivers/dma/xilinx/Makefile
+++ b/drivers/dma/xilinx/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_XILINX_DMA) += xilinx_dma.o
obj-$(CONFIG_XILINX_ZYNQMP_DMA) += zynqmp_dma.o
+obj-$(CONFIG_XILINX_ZYNQMP_DPDMA) += xilinx_dpdma.o
diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c
new file mode 100644
index 000000000000..de28c63afc7d
--- /dev/null
+++ b/drivers/dma/xilinx/xilinx_dpdma.c
@@ -0,0 +1,1543 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx ZynqMP DPDMA Engine driver
+ *
+ * Copyright (C) 2015 - 2019 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_KERNEL);
+ 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))
+ 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;
+ int ret = 0;
+
+ if (config->direction != DMA_MEM_TO_DEV)
+ return -EINVAL;
+
+ /*
+ * 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);
+
+ /* Can't reconfigure a running channel. */
+ if (chan->running) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ /*
+ * 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;
+
+unlock:
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ return ret;
+}
+
+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);
+ 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");