diff options
Diffstat (limited to 'drivers/dma/xilinx/xilinx_dpdma.c')
| -rw-r--r-- | drivers/dma/xilinx/xilinx_dpdma.c | 1535 |
1 files changed, 1535 insertions, 0 deletions
diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c new file mode 100644 index 000000000000..b37197c772aa --- /dev/null +++ b/drivers/dma/xilinx/xilinx_dpdma.c @@ -0,0 +1,1535 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Xilinx ZynqMP DPDMA Engine driver + * + * Copyright (C) 2015 - 2020 Xilinx, Inc. + * + * Author: Hyun Woo Kwon <[email protected]> + */ + +#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: References to descriptors being processed + * @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 + * @xdev: DPDMA device + * @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_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"); |