This is the driver for the AXI Direct Memory Access (AXI DMA) core, which is a soft Xilinx IP core that provides high- bandwidth direct memory access between memory and AXI4-Stream type target peripherals. Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx> --- The deivce tree doc got applied in the slave-dmaengine.git. Changes in v9: - Used the readl_poll_timeout instead of do while loops in the driver as suggested by Moritz Fischer. - Intialize the residue variable to get rid of compilation warining. Changes in v8: - Updated the SG handling as suggested by Nicolae Rosia. - Removed the unnecessary xilinx_dma_channel_set_config API the properties in this API is not being used by the driver. Changes in v7: - Updated license in the driver as suggested by Paul. - Corrected return value in is_idle funtion. Changes in v6: - Fixed Odd indention in the Kconfig. - used GFP_NOWAIT instead of GFP_KERNEL during the desc allocation - Calculated residue in the tx_status instead of complete_descriptor. - Update copy right to 2015. - Modified spin_lock handling moved the spin_lock to the appropriate functions (instead of xilinx_dma_start_transfer doing it xilinx_dma_issue_pending api). - device_control and declare slave caps updated as per newer APi's. Changes in v5: - Modified the xilinx_dma.h header file location to the include/linux/dma/xilinx_dma.h Changes in v4: - Add direction field to DMA descriptor structure and removed from channel structure to avoid duplication. - Check for DMA idle condition before changing the configuration. - Residue is being calculated in complete_descriptor() and is reported to slave driver. Changes in v3: - Rebased on 3.16-rc7 Changes in v2: - Simplified the logic to set SOP and APP words in prep_slave_sg(). - Corrected function description comments to match the return type. - Fixed some minor comments as suggested by Andy. --- drivers/dma/Kconfig | 13 + drivers/dma/xilinx/Makefile | 1 + drivers/dma/xilinx/xilinx_dma.c | 1178 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 1192 insertions(+) create mode 100644 drivers/dma/xilinx/xilinx_dma.c diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 88d474b..5e95f07 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -507,4 +507,17 @@ config QCOM_BAM_DMA Enable support for the QCOM BAM DMA controller. This controller provides DMA capabilities for a variety of on-chip devices. +config XILINX_DMA + tristate "Xilinx AXI DMA Engine" + depends on (ARCH_ZYNQ || MICROBLAZE) + select DMA_ENGINE + help + Enable support for Xilinx AXI DMA Soft IP. + + This engine provides high-bandwidth direct memory access + between memory and AXI4-Stream type target peripherals. + It has two stream interfaces/channels, Memory Mapped to + Stream (MM2S) and Stream to Memory Mapped (S2MM) for the + data transfers. + endif diff --git a/drivers/dma/xilinx/Makefile b/drivers/dma/xilinx/Makefile index 3c4e9f2..6224a49 100644 --- a/drivers/dma/xilinx/Makefile +++ b/drivers/dma/xilinx/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_XILINX_VDMA) += xilinx_vdma.o +obj-$(CONFIG_XILINX_DMA) += xilinx_dma.o diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c new file mode 100644 index 0000000..d19009e --- /dev/null +++ b/drivers/dma/xilinx/xilinx_dma.c @@ -0,0 +1,1178 @@ +/* + * DMA driver for Xilinx DMA Engine + * + * Copyright (C) 2010 - 2015 Xilinx, Inc. All rights reserved. + * + * Based on the Freescale DMA driver. + * + * Description: + * The AXI DMA, is a soft IP, which provides high-bandwidth Direct Memory + * Access between memory and AXI4-Stream-type target peripherals. It can be + * configured to have one channel or two channels and if configured as two + * channels, one is to transmit data from memory to a device and another is + * to receive from a device. + * + * This is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/bitops.h> +#include <linux/dma/xilinx_dma.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_dma.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/slab.h> + +#include "../dmaengine.h" + +/* Register Offsets */ +#define XILINX_DMA_REG_CONTROL 0x00 +#define XILINX_DMA_REG_STATUS 0x04 +#define XILINX_DMA_REG_CURDESC 0x08 +#define XILINX_DMA_REG_TAILDESC 0x10 +#define XILINX_DMA_REG_SRCADDR 0x18 +#define XILINX_DMA_REG_DSTADDR 0x20 +#define XILINX_DMA_REG_BTT 0x28 + +/* Channel/Descriptor Offsets */ +#define XILINX_DMA_MM2S_CTRL_OFFSET 0x00 +#define XILINX_DMA_S2MM_CTRL_OFFSET 0x30 + +/* General register bits definitions */ +#define XILINX_DMA_CR_RUNSTOP_MASK BIT(0) +#define XILINX_DMA_CR_RESET_MASK BIT(2) + +#define XILINX_DMA_CR_DELAY_SHIFT 24 +#define XILINX_DMA_CR_COALESCE_SHIFT 16 + +#define XILINX_DMA_CR_DELAY_MAX GENMASK(7, 0) +#define XILINX_DMA_CR_COALESCE_MAX GENMASK(7, 0) + +#define XILINX_DMA_SR_HALTED_MASK BIT(0) +#define XILINX_DMA_SR_IDLE_MASK BIT(1) + +#define XILINX_DMA_XR_IRQ_IOC_MASK BIT(12) +#define XILINX_DMA_XR_IRQ_DELAY_MASK BIT(13) +#define XILINX_DMA_XR_IRQ_ERROR_MASK BIT(14) +#define XILINX_DMA_XR_IRQ_ALL_MASK GENMASK(14, 12) + +/* BD definitions */ +#define XILINX_DMA_BD_STS_ALL_MASK GENMASK(31, 28) +#define XILINX_DMA_BD_SOP BIT(27) +#define XILINX_DMA_BD_EOP BIT(26) + +/* Hw specific definitions */ +#define XILINX_DMA_MAX_CHANS_PER_DEVICE 0x2 +#define XILINX_DMA_MAX_TRANS_LEN GENMASK(22, 0) + +/* Delay loop counter to prevent hardware failure */ +#define XILINX_DMA_LOOP_COUNT 1000000 + +/* Maximum number of Descriptors */ +#define XILINX_DMA_NUM_DESCS 255 +#define XILINX_DMA_COALESCE_MAX 255 +#define XILINX_DMA_NUM_APP_WORDS 5 + +#define xilinx_dma_poll_timeout(chan, reg, val, cond, delay_us, timeout_us) \ + readl_poll_timeout(chan->xdev->regs + chan->ctrl_offset + reg, val, \ + cond, delay_us, timeout_us) + +/** + * struct xilinx_dma_desc_hw - Hardware Descriptor + * @next_desc: Next Descriptor Pointer @0x00 + * @pad1: Reserved @0x04 + * @buf_addr: Buffer address @0x08 + * @pad2: Reserved @0x0C + * @pad3: Reserved @0x10 + * @pad4: Reserved @0x14 + * @control: Control field @0x18 + * @status: Status field @0x1C + * @app: APP Fields @0x20 - 0x30 + */ +struct xilinx_dma_desc_hw { + u32 next_desc; + u32 pad1; + u32 buf_addr; + u32 pad2; + u32 pad3; + u32 pad4; + u32 control; + u32 status; + u32 app[XILINX_DMA_NUM_APP_WORDS]; +} __aligned(64); + +/** + * struct xilinx_dma_tx_segment - Descriptor segment + * @hw: Hardware descriptor + * @node: Node in the descriptor segments list + * @phys: Physical address of segment + */ +struct xilinx_dma_tx_segment { + struct xilinx_dma_desc_hw hw; + struct list_head node; + dma_addr_t phys; +} __aligned(64); + +/** + * struct xilinx_dma_tx_descriptor - Per Transaction structure + * @async_tx: Async transaction descriptor + * @segments: TX segments list + * @node: Node in the channel descriptors list + * @direction: Transfer direction + */ +struct xilinx_dma_tx_descriptor { + struct dma_async_tx_descriptor async_tx; + struct list_head segments; + struct list_head node; + enum dma_transfer_direction direction; +}; + +/** + * struct xilinx_dma_chan - Driver specific DMA channel structure + * @xdev: Driver specific device structure + * @ctrl_offset: Control registers offset + * @ctrl_reg: Control register value + * @lock: Descriptor operation lock + * @pending_list: Descriptors waiting + * @active_list: Descriptors ready to submit + * @done_list: Complete descriptors + * @free_seg_list: Free descriptors + * @common: DMA common channel + * @seg_v: Statically allocated segments base + * @seg_p: Physical allocated segments base + * @dev: The dma device + * @irq: Channel IRQ + * @id: Channel ID + * @has_sg: Support scatter transfers + * @idle: Check for channel idle + * @err: Channel has errors + * @tasklet: Cleanup work after irq + * @residue: Residue + * @desc_pendingcount: Descriptor pending count + */ +struct xilinx_dma_chan { + struct xilinx_dma_device *xdev; + u32 ctrl_offset; + u32 ctrl_reg; + spinlock_t lock; + struct list_head pending_list; + struct list_head done_list; + struct list_head active_list; + struct list_head free_seg_list; + struct dma_chan common; + struct xilinx_dma_tx_segment *seg_v; + dma_addr_t seg_p; + struct device *dev; + int irq; + int id; + bool has_sg; + bool idle; + int err; + struct tasklet_struct tasklet; + u32 residue; + u32 desc_pendingcount; +}; + +/** + * struct xilinx_dma_device - DMA device structure + * @regs: I/O mapped base address + * @dev: Device Structure + * @common: DMA device structure + * @chan: Driver specific DMA channel + * @has_sg: Specifies whether Scatter-Gather is present or not + */ +struct xilinx_dma_device { + void __iomem *regs; + struct device *dev; + struct dma_device common; + struct xilinx_dma_chan *chan[XILINX_DMA_MAX_CHANS_PER_DEVICE]; + bool has_sg; +}; + +/* Macros */ +#define to_xilinx_chan(chan) \ + container_of(chan, struct xilinx_dma_chan, common) +#define to_dma_tx_descriptor(tx) \ + container_of(tx, struct xilinx_dma_tx_descriptor, async_tx) + +/* IO accessors */ +static inline void dma_write(struct xilinx_dma_chan *chan, u32 reg, u32 value) +{ + iowrite32(value, chan->xdev->regs + reg); +} + +static inline u32 dma_read(struct xilinx_dma_chan *chan, u32 reg) +{ + return ioread32(chan->xdev->regs + reg); +} + +static inline u32 dma_ctrl_read(struct xilinx_dma_chan *chan, u32 reg) +{ + return dma_read(chan, chan->ctrl_offset + reg); +} + +static inline void dma_ctrl_write(struct xilinx_dma_chan *chan, u32 reg, + u32 value) +{ + dma_write(chan, chan->ctrl_offset + reg, value); +} + +/* ----------------------------------------------------------------------------- + * Descriptors and segments alloc and free + */ + +/** + * xilinx_dma_alloc_tx_segment - Allocate transaction segment + * @chan: Driver specific dma channel + * + * Return: The allocated segment on success and NULL on failure. + */ +static struct xilinx_dma_tx_segment * +xilinx_dma_alloc_tx_segment(struct xilinx_dma_chan *chan) +{ + struct xilinx_dma_tx_segment *segment = NULL; + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + if (!list_empty(&chan->free_seg_list)) { + segment = list_first_entry(&chan->free_seg_list, + struct xilinx_dma_tx_segment, + node); + list_del(&segment->node); + } + spin_unlock_irqrestore(&chan->lock, flags); + + return segment; +} + +/** + * xilinx_dma_clean_hw_desc - Clean hardware descriptor + * @hw: HW descriptor to clean + */ +static void xilinx_dma_clean_hw_desc(struct xilinx_dma_desc_hw *hw) +{ + u32 next_desc = hw->next_desc; + + memset(hw, 0, sizeof(struct xilinx_dma_desc_hw)); + + hw->next_desc = next_desc; +} + +/** + * xilinx_dma_free_tx_segment - Free transaction segment + * @chan: Driver specific dma channel + * @segment: dma transaction segment + */ +static void xilinx_dma_free_tx_segment(struct xilinx_dma_chan *chan, + struct xilinx_dma_tx_segment *segment) +{ + xilinx_dma_clean_hw_desc(&segment->hw); + + list_add_tail(&segment->node, &chan->free_seg_list); +} + +/** + * xilinx_dma_tx_descriptor - Allocate transaction descriptor + * @chan: Driver specific dma channel + * + * Return: The allocated descriptor on success and NULL on failure. + */ +static struct xilinx_dma_tx_descriptor * +xilinx_dma_alloc_tx_descriptor(struct xilinx_dma_chan *chan) +{ + struct xilinx_dma_tx_descriptor *desc; + + desc = kzalloc(sizeof(*desc), GFP_NOWAIT); + if (!desc) + return NULL; + + INIT_LIST_HEAD(&desc->segments); + + return desc; +} + +/** + * xilinx_dma_free_tx_descriptor - Free transaction descriptor + * @chan: Driver specific dma channel + * @desc: dma transaction descriptor + */ +static void +xilinx_dma_free_tx_descriptor(struct xilinx_dma_chan *chan, + struct xilinx_dma_tx_descriptor *desc) +{ + struct xilinx_dma_tx_segment *segment, *next; + + if (!desc) + return; + + list_for_each_entry_safe(segment, next, &desc->segments, node) { + list_del(&segment->node); + xilinx_dma_free_tx_segment(chan, segment); + } + + kfree(desc); +} + +/** + * xilinx_dma_alloc_chan_resources - Allocate channel resources + * @dchan: DMA channel + * + * Return: '0' on success and failure value on error + */ +static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan) +{ + struct xilinx_dma_chan *chan = to_xilinx_chan(dchan); + int i; + + /* Allocate the buffer descriptors. */ + chan->seg_v = dma_zalloc_coherent(chan->dev, + sizeof(*chan->seg_v) * + XILINX_DMA_NUM_DESCS, + &chan->seg_p, GFP_KERNEL); + if (!chan->seg_v) { + dev_err(chan->dev, + "unable to allocate channel %d descriptors\n", + chan->id); + return -ENOMEM; + } + + for (i = 0; i < XILINX_DMA_NUM_DESCS; i++) { + chan->seg_v[i].hw.next_desc = + chan->seg_p + sizeof(*chan->seg_v) * + ((i + 1) % XILINX_DMA_NUM_DESCS); + chan->seg_v[i].phys = + chan->seg_p + sizeof(*chan->seg_v) * i; + list_add_tail(&chan->seg_v[i].node, &chan->free_seg_list); + } + + dma_cookie_init(dchan); + + /* Enable interrupts */ + chan->ctrl_reg |= XILINX_DMA_XR_IRQ_ALL_MASK; + dma_ctrl_write(chan, XILINX_DMA_REG_CONTROL, chan->ctrl_reg); + + return 0; +} + +/** + * xilinx_dma_free_desc_list - Free descriptors list + * @chan: Driver specific dma channel + * @list: List to parse and delete the descriptor + */ +static void xilinx_dma_free_desc_list(struct xilinx_dma_chan *chan, + struct list_head *list) +{ + struct xilinx_dma_tx_descriptor *desc, *next; + + list_for_each_entry_safe(desc, next, list, node) { + list_del(&desc->node); + xilinx_dma_free_tx_descriptor(chan, desc); + } +} + +/** + * xilinx_dma_free_descriptors - Free channel descriptors + * @chan: Driver specific dma channel + */ +static void xilinx_dma_free_descriptors(struct xilinx_dma_chan *chan) +{ + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + + xilinx_dma_free_desc_list(chan, &chan->pending_list); + xilinx_dma_free_desc_list(chan, &chan->done_list); + xilinx_dma_free_desc_list(chan, &chan->active_list); + + spin_unlock_irqrestore(&chan->lock, flags); +} + +/** + * xilinx_dma_free_chan_resources - Free channel resources + * @dchan: DMA channel + */ +static void xilinx_dma_free_chan_resources(struct dma_chan *dchan) +{ + struct xilinx_dma_chan *chan = to_xilinx_chan(dchan); + + xilinx_dma_free_descriptors(chan); + + dma_free_coherent(chan->dev, + sizeof(*chan->seg_v) * XILINX_DMA_NUM_DESCS, + chan->seg_v, chan->seg_p); +} + +/** + * xilinx_dma_chan_desc_cleanup - Clean channel descriptors + * @chan: Driver specific dma channel + */ +static void xilinx_dma_chan_desc_cleanup(struct xilinx_dma_chan *chan) +{ + struct xilinx_dma_tx_descriptor *desc; + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + + while (!list_empty(&chan->done_list)) { + dma_async_tx_callback callback; + void *callback_param; + + desc = list_first_entry(&chan->done_list, + struct xilinx_dma_tx_descriptor, node); + + /* Remove from the list of running transactions */ + list_del(&desc->node); + + /* Run the link descriptor callback function */ + callback = desc->async_tx.callback; + callback_param = desc->async_tx.callback_param; + if (callback) { + spin_unlock_irqrestore(&chan->lock, flags); + callback(callback_param); + spin_lock_irqsave(&chan->lock, flags); + } + + /* Run any dependencies, then free the descriptor */ + dma_run_dependencies(&desc->async_tx); + xilinx_dma_free_tx_descriptor(chan, desc); + } + + spin_unlock_irqrestore(&chan->lock, flags); +} + +/** + * xilinx_dma_tx_status - Get dma transaction status + * @dchan: DMA channel + * @cookie: Transaction identifier + * @txstate: Transaction state + * + * Return: DMA transaction status + */ +static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct xilinx_dma_chan *chan = to_xilinx_chan(dchan); + struct xilinx_dma_tx_descriptor *desc; + struct xilinx_dma_tx_segment *segment; + struct xilinx_dma_desc_hw *hw; + enum dma_status ret; + unsigned long flags; + u32 residue = 0; + + ret = dma_cookie_status(dchan, cookie, txstate); + if (ret == DMA_COMPLETE || !txstate) + return ret; + + desc = list_last_entry(&chan->active_list, + struct xilinx_dma_tx_descriptor, node); + + spin_lock_irqsave(&chan->lock, flags); + if (chan->has_sg) { + while (!list_empty(&desc->segments)) { + segment = list_first_entry(&desc->segments, + struct xilinx_dma_tx_segment, node); + hw = &segment->hw; + residue += (hw->control - hw->status) & + XILINX_DMA_MAX_TRANS_LEN; + } + } + + chan->residue = residue; + dma_set_residue(txstate, chan->residue); + spin_unlock_irqrestore(&chan->lock, flags); + + return ret; +} + +/** + * xilinx_dma_halt - Halt DMA channel + * @chan: Driver specific DMA channel + */ +static void xilinx_dma_halt(struct xilinx_dma_chan *chan) +{ + int err = 0; + u32 val; + + chan->ctrl_reg &= ~XILINX_DMA_CR_RUNSTOP_MASK; + dma_ctrl_write(chan, XILINX_DMA_REG_CONTROL, chan->ctrl_reg); + + /* Wait for the hardware to halt */ + err = xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_STATUS, val, + (val & XILINX_DMA_SR_HALTED_MASK), 10, + XILINX_DMA_LOOP_COUNT); + + if (err) { + dev_err(chan->dev, "Cannot stop channel %p: %x\n", + chan, dma_ctrl_read(chan, XILINX_DMA_REG_STATUS)); + chan->err = true; + } +} + +/** + * xilinx_dma_start - Start DMA channel + * @chan: Driver specific DMA channel + */ +static void xilinx_dma_start(struct xilinx_dma_chan *chan) +{ + int err = 0; + u32 val; + + chan->ctrl_reg |= XILINX_DMA_CR_RUNSTOP_MASK; + dma_ctrl_write(chan, XILINX_DMA_REG_CONTROL, chan->ctrl_reg); + + /* Wait for the hardware to start */ + err = xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_STATUS, val, + !(val & XILINX_DMA_SR_HALTED_MASK), 10, + XILINX_DMA_LOOP_COUNT); + + if (err) { + dev_err(chan->dev, "Cannot start channel %p: %x\n", + chan, dma_ctrl_read(chan, XILINX_DMA_REG_STATUS)); + chan->err = true; + } +} + +/** + * xilinx_dma_start_transfer - Starts DMA transfer + * @chan: Driver specific channel struct pointer + */ +static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan) +{ + struct xilinx_dma_tx_descriptor *head_desc, *tail_desc; + struct xilinx_dma_tx_segment *tail_segment; + + if (chan->err) + return; + + if (list_empty(&chan->pending_list)) + return; + + if (!chan->idle) + return; + + head_desc = list_first_entry(&chan->pending_list, + struct xilinx_dma_tx_descriptor, node); + tail_desc = list_last_entry(&chan->pending_list, + struct xilinx_dma_tx_descriptor, node); + tail_segment = list_last_entry(&tail_desc->segments, + struct xilinx_dma_tx_segment, node); + + if (chan->desc_pendingcount <= XILINX_DMA_COALESCE_MAX) { + chan->ctrl_reg &= ~XILINX_DMA_CR_COALESCE_MAX; + chan->ctrl_reg |= chan->desc_pendingcount << + XILINX_DMA_CR_COALESCE_SHIFT; + dma_ctrl_write(chan, XILINX_DMA_REG_CONTROL, chan->ctrl_reg); + } + + if (chan->has_sg) + dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC, + head_desc->async_tx.phys); + + xilinx_dma_start(chan); + + if (chan->err) + return; + + /* Start the transfer */ + if (chan->has_sg) { + dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC, + tail_segment->phys); + } else { + struct xilinx_dma_tx_segment *segment; + struct xilinx_dma_desc_hw *hw; + + segment = list_first_entry(&head_desc->segments, + struct xilinx_dma_tx_segment, node); + hw = &segment->hw; + + if (head_desc->direction == DMA_MEM_TO_DEV) + dma_ctrl_write(chan, XILINX_DMA_REG_SRCADDR, + hw->buf_addr); + else + dma_ctrl_write(chan, XILINX_DMA_REG_DSTADDR, + hw->buf_addr); + + /* Start the transfer */ + dma_ctrl_write(chan, XILINX_DMA_REG_BTT, + hw->control & XILINX_DMA_MAX_TRANS_LEN); + } + + list_splice_tail_init(&chan->pending_list, &chan->active_list); + chan->desc_pendingcount = 0; + chan->idle = false; +} + +/** + * xilinx_dma_issue_pending - Issue pending transactions + * @dchan: DMA channel + */ +static void xilinx_dma_issue_pending(struct dma_chan *dchan) +{ + struct xilinx_dma_chan *chan = to_xilinx_chan(dchan); + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + xilinx_dma_start_transfer(chan); + spin_unlock_irqrestore(&chan->lock, flags); +} + +/** + * xilinx_dma_complete_descriptor - Mark the active descriptor as complete + * @chan : xilinx DMA channel + */ +static void xilinx_dma_complete_descriptor(struct xilinx_dma_chan *chan) +{ + struct xilinx_dma_tx_descriptor *desc, *next; + + if (list_empty(&chan->active_list)) + return; + + list_for_each_entry_safe(desc, next, &chan->active_list, node) { + list_del(&desc->node); + dma_cookie_complete(&desc->async_tx); + list_add_tail(&desc->node, &chan->done_list); + } +} + +/** + * xilinx_dma_chan_reset - Reset DMA channel + * @chan: Driver specific DMA channel + * + * Return: '0' on success and failure value on error + */ +static int xilinx_dma_chan_reset(struct xilinx_dma_chan *chan) +{ + int err = 0; + u32 val; + + chan->ctrl_reg = dma_ctrl_read(chan, XILINX_DMA_REG_CONTROL); + dma_ctrl_write(chan, XILINX_DMA_REG_CONTROL, chan->ctrl_reg | + XILINX_DMA_CR_RESET_MASK); + + /* Wait for the hardware to finish reset */ + err = xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_CONTROL, val, + !(val & XILINX_DMA_CR_RESET_MASK), 10, + XILINX_DMA_LOOP_COUNT); + + if (err) { + dev_err(chan->dev, "reset timeout, cr %x, sr %x\n", + dma_ctrl_read(chan, XILINX_DMA_REG_CONTROL), + dma_ctrl_read(chan, XILINX_DMA_REG_STATUS)); + return -EBUSY; + } + + chan->err = false; + + return err; +} + +/** + * xilinx_dma_irq_handler - DMA Interrupt handler + * @irq: IRQ number + * @data: Pointer to the Xilinx DMA channel structure + * + * Return: IRQ_HANDLED/IRQ_NONE + */ +static irqreturn_t xilinx_dma_irq_handler(int irq, void *data) +{ + struct xilinx_dma_chan *chan = data; + u32 status; + + /* Read the status and ack the interrupts. */ + status = dma_ctrl_read(chan, XILINX_DMA_REG_STATUS); + if (!(status & XILINX_DMA_XR_IRQ_ALL_MASK)) + return IRQ_NONE; + + dma_ctrl_write(chan, XILINX_DMA_REG_STATUS, + status & XILINX_DMA_XR_IRQ_ALL_MASK); + + if (status & XILINX_DMA_XR_IRQ_ERROR_MASK) { + dev_err(chan->dev, + "Channel %p has errors %x, cdr %x tdr %x\n", + chan, dma_ctrl_read(chan, XILINX_DMA_REG_STATUS), + dma_ctrl_read(chan, XILINX_DMA_REG_CURDESC), + dma_ctrl_read(chan, XILINX_DMA_REG_TAILDESC)); + chan->err = true; + } + + /* + * Device takes too long to do the transfer when user requires + * responsiveness + */ + if (status & XILINX_DMA_XR_IRQ_DELAY_MASK) + dev_dbg(chan->dev, "Inter-packet latency too long\n"); + + if (status & XILINX_DMA_XR_IRQ_IOC_MASK) { + spin_lock(&chan->lock); + xilinx_dma_complete_descriptor(chan); + chan->idle = true; + xilinx_dma_start_transfer(chan); + spin_unlock(&chan->lock); + } + + tasklet_schedule(&chan->tasklet); + return IRQ_HANDLED; +} + +/** + * xilinx_dma_do_tasklet - Schedule completion tasklet + * @data: Pointer to the Xilinx dma channel structure + */ +static void xilinx_dma_do_tasklet(unsigned long data) +{ + struct xilinx_dma_chan *chan = (struct xilinx_dma_chan *)data; + + xilinx_dma_chan_desc_cleanup(chan); +} + +/** + * append_desc_queue - Queuing descriptor + * @chan: Driver specific dma channel + * @desc: dma transaction descriptor + */ +static void append_desc_queue(struct xilinx_dma_chan *chan, + struct xilinx_dma_tx_descriptor *desc) +{ + struct xilinx_dma_tx_segment *tail_segment; + struct xilinx_dma_tx_descriptor *tail_desc; + + if (list_empty(&chan->pending_list)) + goto append; + + /* + * Add the hardware descriptor to the chain of hardware descriptors + * that already exists in memory. + */ + tail_desc = list_last_entry(&chan->pending_list, + struct xilinx_dma_tx_descriptor, node); + tail_segment = list_last_entry(&tail_desc->segments, + struct xilinx_dma_tx_segment, node); + tail_segment->hw.next_desc = (u32)desc->async_tx.phys; + + /* + * Add the software descriptor and all children to the list + * of pending transactions + */ +append: + list_add_tail(&desc->node, &chan->pending_list); + chan->desc_pendingcount++; + + if (unlikely(chan->desc_pendingcount > XILINX_DMA_COALESCE_MAX)) { + dev_dbg(chan->dev, "desc pendingcount is too high\n"); + chan->desc_pendingcount = XILINX_DMA_COALESCE_MAX; + BUG(); + } +} + +/** + * xilinx_dma_tx_submit - Submit DMA transaction + * @tx: Async transaction descriptor + * + * Return: cookie value on success and failure value on error + */ +static dma_cookie_t xilinx_dma_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct xilinx_dma_tx_descriptor *desc = to_dma_tx_descriptor(tx); + struct xilinx_dma_chan *chan = to_xilinx_chan(tx->chan); + dma_cookie_t cookie; + unsigned long flags; + int err; + + if (chan->err) { + /* + * If reset fails, need to hard reset the system. + * Channel is no longer functional + */ + err = xilinx_dma_chan_reset(chan); + if (err < 0) + return err; + } + + spin_lock_irqsave(&chan->lock, flags); + + cookie = dma_cookie_assign(tx); + + /* Put this transaction onto the tail of the pending queue */ + append_desc_queue(chan, desc); + + spin_unlock_irqrestore(&chan->lock, flags); + + return cookie; +} + +/** + * xilinx_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction + * @dchan: DMA channel + * @sgl: scatterlist to transfer to/from + * @sg_len: number of entries in @scatterlist + * @direction: DMA direction + * @flags: transfer ack flags + * @context: APP words of the descriptor + * + * Return: Async transaction descriptor on success and NULL on failure + */ +static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg( + struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len, + enum dma_transfer_direction direction, unsigned long flags, + void *context) +{ + struct xilinx_dma_chan *chan = to_xilinx_chan(dchan); + struct xilinx_dma_tx_descriptor *desc; + struct xilinx_dma_tx_segment *segment; + u32 *app_w = (u32 *)context; + struct scatterlist *sg; + size_t copy, sg_used; + int i; + + if (!is_slave_direction(direction)) + return NULL; + + /* Allocate a transaction descriptor. */ + desc = xilinx_dma_alloc_tx_descriptor(chan); + if (!desc) + return NULL; + + desc->direction = direction; + dma_async_tx_descriptor_init(&desc->async_tx, &chan->common); + desc->async_tx.tx_submit = xilinx_dma_tx_submit; + + /* Build transactions using information in the scatter gather list */ + for_each_sg(sgl, sg, sg_len, i) { + sg_used = 0; + + /* Loop until the entire scatterlist entry is used */ + while (sg_used < sg_dma_len(sg)) { + struct xilinx_dma_desc_hw *hw; + + /* Get a free segment */ + segment = xilinx_dma_alloc_tx_segment(chan); + if (!segment) + goto error; + + /* + * Calculate the maximum number of bytes to transfer, + * making sure it is less than the hw limit + */ + copy = min_t(size_t, sg_dma_len(sg) - sg_used, + XILINX_DMA_MAX_TRANS_LEN); + hw = &segment->hw; + + /* Fill in the descriptor */ + hw->buf_addr = sg_dma_address(sg) + sg_used; + + hw->control = copy; + + if (direction == DMA_MEM_TO_DEV) { + if (app_w) + memcpy(hw->app, app_w, sizeof(u32) * + XILINX_DMA_NUM_APP_WORDS); + } + + sg_used += copy; + + /* + * Insert the segment into the descriptor segments + * list. + */ + list_add_tail(&segment->node, &desc->segments); + } + } + + segment = list_first_entry(&desc->segments, + struct xilinx_dma_tx_segment, node); + desc->async_tx.phys = segment->phys; + + /* For the last DMA_MEM_TO_DEV transfer, set EOP */ + if (direction == DMA_MEM_TO_DEV) { + segment->hw.control |= XILINX_DMA_BD_SOP; + segment = list_last_entry(&desc->segments, + struct xilinx_dma_tx_segment, + node); + segment->hw.control |= XILINX_DMA_BD_EOP; + } + + return &desc->async_tx; + +error: + xilinx_dma_free_tx_descriptor(chan, desc); + return NULL; +} + +/** + * xilinx_dma_terminate_all - Halt the channel and free descriptors + * @dchan: DMA Channel pointer + * + * Return: '0' always + */ +static int xilinx_dma_terminate_all(struct dma_chan *dchan) +{ + struct xilinx_dma_chan *chan = to_xilinx_chan(dchan); + + /* Halt the DMA engine */ + xilinx_dma_halt(chan); + + /* Remove and free all of the descriptors in the lists */ + xilinx_dma_free_descriptors(chan); + + return 0; +} + +/** + * xilinx_dma_chan_remove - Per Channel remove function + * @chan: Driver specific DMA channel + */ +static void xilinx_dma_chan_remove(struct xilinx_dma_chan *chan) +{ + /* Disable interrupts */ + chan->ctrl_reg &= ~XILINX_DMA_XR_IRQ_ALL_MASK; + dma_ctrl_write(chan, XILINX_DMA_REG_CONTROL, chan->ctrl_reg); + + if (chan->irq > 0) + free_irq(chan->irq, chan); + + tasklet_kill(&chan->tasklet); + + list_del(&chan->common.device_node); +} + +/** + * xilinx_dma_chan_probe - Per Channel Probing + * It get channel features from the device tree entry and + * initialize special channel handling routines + * + * @xdev: Driver specific device structure + * @node: Device node + * + * Return: '0' on success and failure value on error + */ +static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev, + struct device_node *node) +{ + struct xilinx_dma_chan *chan; + int err; + bool has_dre; + u32 value, width = 0; + + /* alloc channel */ + chan = devm_kzalloc(xdev->dev, sizeof(*chan), GFP_KERNEL); + if (!chan) + return -ENOMEM; + + chan->dev = xdev->dev; + chan->xdev = xdev; + chan->has_sg = xdev->has_sg; + chan->desc_pendingcount = 0x0; + + has_dre = of_property_read_bool(node, "xlnx,include-dre"); + + err = of_property_read_u32(node, "xlnx,datawidth", &value); + if (err) { + dev_err(xdev->dev, "unable to read datawidth property"); + return err; + } + + width = value >> 3; /* Convert bits to bytes */ + + /* If data width is greater than 8 bytes, DRE is not in hw */ + if (width > 8) + has_dre = false; + + if (!has_dre) + xdev->common.copy_align = fls(width - 1); + + if (of_device_is_compatible(node, "xlnx,axi-dma-mm2s-channel")) { + chan->id = 0; + chan->ctrl_offset = XILINX_DMA_MM2S_CTRL_OFFSET; + } else if (of_device_is_compatible(node, "xlnx,axi-dma-s2mm-channel")) { + chan->id = 1; + chan->ctrl_offset = XILINX_DMA_S2MM_CTRL_OFFSET; + } else { + dev_err(xdev->dev, "Invalid channel compatible node\n"); + return -EINVAL; + } + + xdev->chan[chan->id] = chan; + + /* Initialize the channel */ + err = xilinx_dma_chan_reset(chan); + if (err) { + dev_err(xdev->dev, "Reset channel failed\n"); + return err; + } + + spin_lock_init(&chan->lock); + INIT_LIST_HEAD(&chan->pending_list); + INIT_LIST_HEAD(&chan->done_list); + INIT_LIST_HEAD(&chan->active_list); + INIT_LIST_HEAD(&chan->free_seg_list); + + chan->common.device = &xdev->common; + + /* find the IRQ line, if it exists in the device tree */ + chan->irq = irq_of_parse_and_map(node, 0); + err = request_irq(chan->irq, xilinx_dma_irq_handler, + IRQF_SHARED, + "xilinx-dma-controller", chan); + if (err) { + dev_err(xdev->dev, "unable to request IRQ %d\n", chan->irq); + return err; + } + + /* Initialize the tasklet */ + tasklet_init(&chan->tasklet, xilinx_dma_do_tasklet, + (unsigned long)chan); + + /* Add the channel to DMA device channel list */ + list_add_tail(&chan->common.device_node, &xdev->common.channels); + + chan->idle = true; + + return 0; +} + +/** + * of_dma_xilinx_xlate - Translation function + * @dma_spec: Pointer to DMA specifier as found in the device tree + * @ofdma: Pointer to DMA controller data + * + * Return: DMA channel pointer on success and NULL on error + */ +static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct xilinx_dma_device *xdev = ofdma->of_dma_data; + int chan_id = dma_spec->args[0]; + + if (chan_id >= XILINX_DMA_MAX_CHANS_PER_DEVICE) + return NULL; + + return dma_get_slave_channel(&xdev->chan[chan_id]->common); +} + +/** + * xilinx_dma_probe - Driver probe function + * @pdev: Pointer to the platform_device structure + * + * Return: '0' on success and failure value on error + */ +static int xilinx_dma_probe(struct platform_device *pdev) +{ + struct xilinx_dma_device *xdev; + struct device_node *child, *node; + struct resource *res; + int i, ret; + + xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL); + if (!xdev) + return -ENOMEM; + + xdev->dev = &(pdev->dev); + INIT_LIST_HEAD(&xdev->common.channels); + + node = pdev->dev.of_node; + + /* Map the registers */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + xdev->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(xdev->regs)) + return PTR_ERR(xdev->regs); + + /* Check if SG is enabled */ + xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg"); + + /* Axi DMA only do slave transfers */ + dma_cap_set(DMA_SLAVE, xdev->common.cap_mask); + dma_cap_set(DMA_PRIVATE, xdev->common.cap_mask); + xdev->common.device_prep_slave_sg = xilinx_dma_prep_slave_sg; + xdev->common.device_terminate_all = xilinx_dma_terminate_all; + xdev->common.device_issue_pending = xilinx_dma_issue_pending; + xdev->common.device_alloc_chan_resources = + xilinx_dma_alloc_chan_resources; + xdev->common.device_free_chan_resources = + xilinx_dma_free_chan_resources; + xdev->common.device_tx_status = xilinx_dma_tx_status; + xdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); + xdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT; + xdev->common.dev = &pdev->dev; + + platform_set_drvdata(pdev, xdev); + + for_each_child_of_node(node, child) { + ret = xilinx_dma_chan_probe(xdev, child); + if (ret) { + dev_err(&pdev->dev, "Probing channels failed\n"); + goto free_chan_resources; + } + } + + dma_async_device_register(&xdev->common); + + ret = of_dma_controller_register(node, of_dma_xilinx_xlate, xdev); + if (ret) { + dev_err(&pdev->dev, "Unable to register DMA to DT\n"); + dma_async_device_unregister(&xdev->common); + goto free_chan_resources; + } + + dev_info(&pdev->dev, "Xilinx AXI DMA Engine driver Probed!!\n"); + + return 0; + +free_chan_resources: + for (i = 0; i < XILINX_DMA_MAX_CHANS_PER_DEVICE; i++) + if (xdev->chan[i]) + xilinx_dma_chan_remove(xdev->chan[i]); + + return ret; +} + +/** + * xilinx_dma_remove - Driver remove function + * @pdev: Pointer to the platform_device structure + * + * Return: Always '0' + */ +static int xilinx_dma_remove(struct platform_device *pdev) +{ + struct xilinx_dma_device *xdev = platform_get_drvdata(pdev); + int i; + + of_dma_controller_free(pdev->dev.of_node); + dma_async_device_unregister(&xdev->common); + + for (i = 0; i < XILINX_DMA_MAX_CHANS_PER_DEVICE; i++) + if (xdev->chan[i]) + xilinx_dma_chan_remove(xdev->chan[i]); + + return 0; +} + +static const struct of_device_id xilinx_dma_of_match[] = { + { .compatible = "xlnx,axi-dma-1.00.a",}, + {} +}; +MODULE_DEVICE_TABLE(of, xilinx_dma_of_match); + +static struct platform_driver xilinx_dma_driver = { + .driver = { + .name = "xilinx-dma", + .of_match_table = xilinx_dma_of_match, + }, + .probe = xilinx_dma_probe, + .remove = xilinx_dma_remove, +}; + +module_platform_driver(xilinx_dma_driver); + +MODULE_AUTHOR("Xilinx, Inc."); +MODULE_DESCRIPTION("Xilinx DMA driver"); +MODULE_LICENSE("GPL"); -- 2.1.2 -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html