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RULEID:; SRVR:BY2FFO11HUB025; X-Forefront-PRVS: 052670E5A4 X-OriginatorOrg: xilinx.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Mar 2015 05:08:58.4087 (UTC) X-MS-Exchange-CrossTenant-Id: 657af505-d5df-48d0-8300-c31994686c5c X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=657af505-d5df-48d0-8300-c31994686c5c; Ip=[149.199.60.100]; Helo=[xsj-pvapsmtpgw02] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY2FFO11HUB025 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150324_220922_875120_39B14798 X-CRM114-Status: GOOD ( 21.03 ) X-Spam-Score: -0.0 (/) Cc: linux-kernel@vger.kernel.org, Srikanth Thokala , appand@xilinx.com, dmaengine@vger.kernel.org, Kedareswara rao Appana , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This is the driver for the AXI Central Direct Memory Access (AXI CDMA) core, which is a soft Xilinx IP core that provides high-bandwidth Direct Memory Access (DMA) between a memory-mapped source address and a memory-mapped destination address. This module works on Zynq (ARM Based SoC) and Microblaze platforms. Signed-off-by: Srikanth Thokala Signed-off-by: Kedareswara rao Appana --- This patch is rebased on top of dma: xilinx-dma: move header file to common location. Changes in v3: - Check for CDMA idle condition before changing the configuration. - Modified the xilinx_dma.h header file location to the include/linux/dma/xilinx_dma.h Changes in v2: - Rebased on 3.16-rc7. drivers/dma/Kconfig | 12 + drivers/dma/xilinx/Makefile | 1 + drivers/dma/xilinx/xilinx_cdma.c | 1000 ++++++++++++++++++++++++++++++++++++++ include/linux/dma/xilinx_dma.h | 15 +- 4 files changed, 1027 insertions(+), 1 deletion(-) create mode 100644 drivers/dma/xilinx/xilinx_cdma.c diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index a874b6e..1bc17c6 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -425,6 +425,18 @@ config IMG_MDC_DMA help Enable support for the IMG multi-threaded DMA controller (MDC). +config XILINX_CDMA + tristate "Xilinx AXI CDMA Engine" + depends on (ARCH_ZYNQ || MICROBLAZE) + select DMA_ENGINE + help + Enable support for Xilinx AXI CDMA Soft IP. + + The AXI CDMA is a soft IP which provides high-bandwidth + Direct Memory Access (DMA) between a memory-mapped source + address and a memory-mapped destination address using the + AXI4 protocol. + config DMA_ENGINE bool diff --git a/drivers/dma/xilinx/Makefile b/drivers/dma/xilinx/Makefile index 3c4e9f2..e1dee77 100644 --- a/drivers/dma/xilinx/Makefile +++ b/drivers/dma/xilinx/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_XILINX_VDMA) += xilinx_vdma.o +obj-$(CONFIG_XILINX_CDMA) += xilinx_cdma.o diff --git a/drivers/dma/xilinx/xilinx_cdma.c b/drivers/dma/xilinx/xilinx_cdma.c new file mode 100644 index 0000000..ff82fab --- /dev/null +++ b/drivers/dma/xilinx/xilinx_cdma.c @@ -0,0 +1,1000 @@ +/* + * DMA driver for Xilinx Central DMA Engine + * + * Copyright (C) 2010 - 2015 Xilinx, Inc. All rights reserved. + * + * Based on the Freescale DMA driver. + * + * Description: + * The AXI CDMA, is a soft IP, which provides high-bandwidth Direct Memory + * Access (DMA) between a memory-mapped source address and a memory-mapped + * destination address. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../dmaengine.h" + +/* Register Offsets */ +#define XILINX_CDMA_CONTROL_OFFSET 0x00 +#define XILINX_CDMA_STATUS_OFFSET 0x04 +#define XILINX_CDMA_CDESC_OFFSET 0x08 +#define XILINX_CDMA_TDESC_OFFSET 0x10 +#define XILINX_CDMA_SRCADDR_OFFSET 0x18 +#define XILINX_CDMA_DSTADDR_OFFSET 0x20 +#define XILINX_CDMA_BTT_OFFSET 0x28 + +/* General register bits definitions */ +#define XILINX_CDMA_CR_RESET BIT(2) +#define XILINX_CDMA_CR_SGMODE BIT(3) + +#define XILINX_CDMA_SR_IDLE BIT(1) + +#define XILINX_CDMA_XR_IRQ_IOC_MASK BIT(12) +#define XILINX_CDMA_XR_IRQ_DELAY_MASK BIT(13) +#define XILINX_CDMA_XR_IRQ_ERROR_MASK BIT(14) +#define XILINX_CDMA_XR_IRQ_ALL_MASK GENMASK(14, 12) + +#define XILINX_CDMA_XR_DELAY_MASK GENMASK(31, 24) +#define XILINX_CDMA_XR_COALESCE_MASK GENMASK(23, 16) + +#define XILINX_CDMA_DELAY_MAX GENMASK(7, 0) +#define XILINX_CDMA_DELAY_SHIFT 24 + +#define XILINX_CDMA_COALESCE_MAX GENMASK(7, 0) +#define XILINX_CDMA_COALESCE_SHIFT 16 + +/* Delay loop counter to prevent hardware failure */ +#define XILINX_CDMA_RESET_LOOP 1000000 + +/* Maximum transfer length */ +#define XILINX_CDMA_MAX_TRANS_LEN GENMASK(22, 0) + +/** + * struct xilinx_cdma_desc_hw - Hardware Descriptor + * @next_desc: Next Descriptor Pointer @0x00 + * @pad1: Reserved @0x04 + * @src_addr: Source address @0x08 + * @pad2: Reserved @0x0C + * @dest_addr: Destination address @0x10 + * @pad3: Reserved @0x14 + * @control: Control field @0x18 + * @status: Status field @0x1C + */ +struct xilinx_cdma_desc_hw { + u32 next_desc; + u32 pad1; + u32 src_addr; + u32 pad2; + u32 dest_addr; + u32 pad3; + u32 control; + u32 status; +} __aligned(64); + +/** + * struct xilinx_cdma_tx_segment - Descriptor segment + * @hw: Hardware descriptor + * @node: Node in the descriptor segments list + * @phys: Physical address of segment + */ +struct xilinx_cdma_tx_segment { + struct xilinx_cdma_desc_hw hw; + struct list_head node; + dma_addr_t phys; +} __aligned(64); + +/** + * struct xilinx_cdma_tx_descriptor - Per Transaction structure + * @async_tx: Async transaction descriptor + * @segments: TX segments list + * @node: Node in the channel descriptors list + */ +struct xilinx_cdma_tx_descriptor { + struct dma_async_tx_descriptor async_tx; + struct list_head segments; + struct list_head node; +}; + +/** + * struct xilinx_cdma_chan - Driver specific cdma channel structure + * @xdev: Driver specific device structure + * @lock: Descriptor operation lock + * @done_list: Complete descriptors + * @pending_list: Descriptors waiting + * @active_desc: Active descriptor + * @allocated_desc: Allocated descriptor + * @common: DMA common channel + * @desc_pool: Descriptors pool + * @dev: The dma device + * @irq: Channel IRQ + * @has_sg: Support scatter transfers + * @err: Channel has errors + * @tasklet: Cleanup work after irq + */ +struct xilinx_cdma_chan { + struct xilinx_cdma_device *xdev; + spinlock_t lock; + struct list_head done_list; + struct list_head pending_list; + struct xilinx_cdma_tx_descriptor *active_desc; + struct xilinx_cdma_tx_descriptor *allocated_desc; + struct dma_chan common; + struct dma_pool *desc_pool; + struct device *dev; + int irq; + bool has_sg; + int err; + struct tasklet_struct tasklet; +}; + +/** + * struct xilinx_cdma_device - CDMA device structure + * @regs: I/O mapped base address + * @dev: Device Structure + * @common: DMA device structure + * @chan: Driver specific cdma channel + * @has_sg: Specifies whether Scatter-Gather is present or not + */ +struct xilinx_cdma_device { + void __iomem *regs; + struct device *dev; + struct dma_device common; + struct xilinx_cdma_chan *chan; + bool has_sg; +}; + +/* Macros */ +#define to_xilinx_chan(chan) \ + container_of(chan, struct xilinx_cdma_chan, common) +#define to_cdma_tx_descriptor(tx) \ + container_of(tx, struct xilinx_cdma_tx_descriptor, async_tx) + +/* IO accessors */ +static inline void cdma_write(struct xilinx_cdma_chan *chan, u32 reg, u32 val) +{ + writel(val, chan->xdev->regs + reg); +} + +static inline u32 cdma_read(struct xilinx_cdma_chan *chan, u32 reg) +{ + return readl(chan->xdev->regs + reg); +} + +static inline void cdma_ctrl_clr(struct xilinx_cdma_chan *chan, u32 reg, + u32 clr) +{ + cdma_write(chan, reg, cdma_read(chan, reg) & ~clr); +} + +static inline void cdma_ctrl_set(struct xilinx_cdma_chan *chan, u32 reg, + u32 set) +{ + cdma_write(chan, reg, cdma_read(chan, reg) | set); +} + +/* ----------------------------------------------------------------------------- + * Descriptors and segments alloc and free + */ + +/** + * xilinx_cdma_alloc_tx_segment - Allocate transaction segment + * @chan: Driver specific cdma channel + * + * Return: The allocated segment on success and NULL on failure. + */ +static struct xilinx_cdma_tx_segment * +xilinx_cdma_alloc_tx_segment(struct xilinx_cdma_chan *chan) +{ + struct xilinx_cdma_tx_segment *segment; + dma_addr_t phys; + + segment = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &phys); + if (!segment) + return NULL; + + memset(segment, 0, sizeof(*segment)); + segment->phys = phys; + + return segment; +} + +/** + * xilinx_cdma_free_tx_segment - Free transaction segment + * @chan: Driver specific cdma channel + * @segment: cdma transaction segment + */ +static void xilinx_cdma_free_tx_segment(struct xilinx_cdma_chan *chan, + struct xilinx_cdma_tx_segment *segment) +{ + dma_pool_free(chan->desc_pool, segment, segment->phys); +} + +/** + * xilinx_cdma_tx_descriptor - Allocate transaction descriptor + * @chan: Driver specific cdma channel + * + * Return: The allocated descriptor on success and NULL on failure. + */ +static struct xilinx_cdma_tx_descriptor * +xilinx_cdma_alloc_tx_descriptor(struct xilinx_cdma_chan *chan) +{ + struct xilinx_cdma_tx_descriptor *desc; + unsigned long flags; + + if (chan->allocated_desc) + return chan->allocated_desc; + + desc = kzalloc(sizeof(*desc), GFP_KERNEL); + if (!desc) + return NULL; + + spin_lock_irqsave(&chan->lock, flags); + chan->allocated_desc = desc; + spin_unlock_irqrestore(&chan->lock, flags); + + INIT_LIST_HEAD(&desc->segments); + + return desc; +} + +/** + * xilinx_cdma_free_tx_descriptor - Free transaction descriptor + * @chan: Driver specific cdma channel + * @desc: cdma transaction descriptor + */ +static void +xilinx_cdma_free_tx_descriptor(struct xilinx_cdma_chan *chan, + struct xilinx_cdma_tx_descriptor *desc) +{ + struct xilinx_cdma_tx_segment *segment, *next; + + if (!desc) + return; + + list_for_each_entry_safe(segment, next, &desc->segments, node) { + list_del(&segment->node); + xilinx_cdma_free_tx_segment(chan, segment); + } + + kfree(desc); +} + +/** + * xilinx_cdma_alloc_chan_resources - Allocate channel resources + * @dchan: DMA channel + * + * Return: '0' on success and failure value on error + */ +static int xilinx_cdma_alloc_chan_resources(struct dma_chan *dchan) +{ + struct xilinx_cdma_chan *chan = to_xilinx_chan(dchan); + + /* Has this channel already been allocated? */ + if (chan->desc_pool) + return 0; + + /* + * We need the descriptor to be aligned to 64bytes + * for meeting Xilinx DMA specification requirement. + */ + chan->desc_pool = dma_pool_create("xilinx_cdma_desc_pool", + chan->dev, + sizeof(struct xilinx_cdma_tx_segment), + __alignof__(struct xilinx_cdma_tx_segment), 0); + if (!chan->desc_pool) { + dev_err(chan->dev, + "unable to allocate channel descriptor pool\n"); + return -ENOMEM; + } + + dma_cookie_init(dchan); + return 0; +} + +/** + * xilinx_cdma_free_desc_list - Free descriptors list + * @chan: Driver specific cdma channel + * @list: List to parse and delete the descriptor + */ +static void xilinx_cdma_free_desc_list(struct xilinx_cdma_chan *chan, + struct list_head *list) +{ + struct xilinx_cdma_tx_descriptor *desc, *next; + + list_for_each_entry_safe(desc, next, list, node) { + list_del(&desc->node); + xilinx_cdma_free_tx_descriptor(chan, desc); + } +} + +/** + * xilinx_cdma_free_chan_resources - Free channel resources + * @dchan: DMA channel + */ +static void xilinx_cdma_free_chan_resources(struct dma_chan *dchan) +{ + struct xilinx_cdma_chan *chan = to_xilinx_chan(dchan); + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + xilinx_cdma_free_desc_list(chan, &chan->done_list); + xilinx_cdma_free_desc_list(chan, &chan->pending_list); + spin_unlock_irqrestore(&chan->lock, flags); + + dma_pool_destroy(chan->desc_pool); + chan->desc_pool = NULL; +} + +/** + * xilinx_cdma_chan_desc_cleanup - Clean channel descriptors + * @chan: Driver specific cdma channel + */ +static void xilinx_cdma_chan_desc_cleanup(struct xilinx_cdma_chan *chan) +{ + struct xilinx_cdma_tx_descriptor *desc, *next; + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + + list_for_each_entry_safe(desc, next, &chan->done_list, node) { + dma_async_tx_callback callback; + void *callback_param; + + /* Remove from the list of running transactions */ + list_del(&desc->node); + + /* Run the link descriptor callback function */ + callback = desc->async_tx.callback; + callback_param = desc->async_tx.callback_param; + if (callback) { + spin_unlock_irqrestore(&chan->lock, flags); + callback(callback_param); + spin_lock_irqsave(&chan->lock, flags); + } + + /* Run any dependencies, then free the descriptor */ + dma_run_dependencies(&desc->async_tx); + xilinx_cdma_free_tx_descriptor(chan, desc); + } + + spin_unlock_irqrestore(&chan->lock, flags); +} + +/** + * xilinx_cdma_tx_status - Get CDMA transaction status + * @dchan: DMA channel + * @cookie: Transaction identifier + * @txstate: Transaction state + * + * Return: DMA transaction status + */ +static enum dma_status xilinx_tx_status(struct dma_chan *dchan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + return dma_cookie_status(dchan, cookie, txstate); +} + +/** + * xilinx_cdma_is_idle - Check if cdma channel is idle + * @chan: Driver specific cdma channel + * + * Return: 'true' if idle, 'false' if not. + */ +static bool cdma_is_idle(struct xilinx_cdma_chan *chan) +{ + return cdma_read(chan, XILINX_CDMA_STATUS_OFFSET) & XILINX_CDMA_SR_IDLE; +} + +/** + * xilinx_cdma_start_transfer - Starts cdma transfer + * @chan: Driver specific channel struct pointer + */ +static void xilinx_cdma_start_transfer(struct xilinx_cdma_chan *chan) +{ + unsigned long flags; + struct xilinx_cdma_tx_descriptor *desc; + struct xilinx_cdma_tx_segment *head, *tail; + + if (chan->err) + return; + + spin_lock_irqsave(&chan->lock, flags); + + if (list_empty(&chan->pending_list)) + goto out_unlock; + + /* If hardware is busy, cannot submit */ + if (!cdma_is_idle(chan)) { + dev_dbg(chan->dev, "DMA controller still busy %x\n", + cdma_read(chan, XILINX_CDMA_STATUS_OFFSET)); + goto out_unlock; + } + + desc = list_first_entry(&chan->pending_list, + struct xilinx_cdma_tx_descriptor, node); + + if (chan->has_sg) { + head = list_first_entry(&desc->segments, + struct xilinx_cdma_tx_segment, node); + tail = list_entry(desc->segments.prev, + struct xilinx_cdma_tx_segment, node); + + cdma_write(chan, XILINX_CDMA_CDESC_OFFSET, head->phys); + + /* Update tail ptr register which will start the transfer */ + cdma_write(chan, XILINX_CDMA_TDESC_OFFSET, tail->phys); + } else { + /* In simple mode */ + struct xilinx_cdma_tx_segment *segment; + struct xilinx_cdma_desc_hw *hw; + + segment = list_first_entry(&desc->segments, + struct xilinx_cdma_tx_segment, + node); + + hw = &segment->hw; + + cdma_write(chan, XILINX_CDMA_SRCADDR_OFFSET, hw->src_addr); + cdma_write(chan, XILINX_CDMA_DSTADDR_OFFSET, hw->dest_addr); + + /* Start the transfer */ + cdma_write(chan, XILINX_CDMA_BTT_OFFSET, + hw->control & XILINX_CDMA_MAX_TRANS_LEN); + } + + list_del(&desc->node); + chan->active_desc = desc; + +out_unlock: + spin_unlock_irqrestore(&chan->lock, flags); +} + +/** + * xilinx_cdma_issue_pending - Issue pending transactions + * @dchan: DMA channel + */ +static void xilinx_cdma_issue_pending(struct dma_chan *dchan) +{ + struct xilinx_cdma_chan *chan = to_xilinx_chan(dchan); + + xilinx_cdma_start_transfer(chan); +} + +/** + * xilinx_cdma_complete_descriptor - Mark the active descriptor as complete + * @chan : xilinx DMA channel + */ +static void xilinx_cdma_complete_descriptor(struct xilinx_cdma_chan *chan) +{ + struct xilinx_cdma_tx_descriptor *desc; + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + + desc = chan->active_desc; + if (!desc) { + dev_dbg(chan->dev, "no running descriptors\n"); + goto out_unlock; + } + + dma_cookie_complete(&desc->async_tx); + list_add_tail(&desc->node, &chan->done_list); + + chan->active_desc = NULL; + +out_unlock: + spin_unlock_irqrestore(&chan->lock, flags); +} + +/** + * xilinx_cdma_chan_reset - Reset CDMA channel + * @chan: Driver specific CDMA channel + * + * Return: '0' on success and failure value on error + */ +static int xilinx_cdma_chan_reset(struct xilinx_cdma_chan *chan) +{ + int loop = XILINX_CDMA_RESET_LOOP; + u32 tmp; + + cdma_ctrl_set(chan, XILINX_CDMA_CONTROL_OFFSET, + XILINX_CDMA_CR_RESET); + + tmp = cdma_read(chan, XILINX_CDMA_CONTROL_OFFSET) & + XILINX_CDMA_CR_RESET; + + /* Wait for the hardware to finish reset */ + do { + tmp = cdma_read(chan, XILINX_CDMA_CONTROL_OFFSET) & + XILINX_CDMA_CR_RESET; + } while (loop-- && tmp); + + if (!loop) { + dev_err(chan->dev, "reset timeout, cr %x, sr %x\n", + cdma_read(chan, XILINX_CDMA_CONTROL_OFFSET), + cdma_read(chan, XILINX_CDMA_STATUS_OFFSET)); + return -EBUSY; + } + + /* Enable interrupts */ + cdma_ctrl_set(chan, XILINX_CDMA_CONTROL_OFFSET, + XILINX_CDMA_XR_IRQ_ALL_MASK); + + /* Enable SG Mode */ + if (chan->has_sg) + cdma_ctrl_set(chan, XILINX_CDMA_CONTROL_OFFSET, + XILINX_CDMA_CR_SGMODE); + return 0; +} + +/** + * xilinx_cdma_irq_handler - CDMA Interrupt handler + * @irq: IRQ number + * @data: Pointer to the Xilinx CDMA channel structure + * + * Return: IRQ_HANDLED/IRQ_NONE + */ +static irqreturn_t xilinx_cdma_irq_handler(int irq, void *data) +{ + struct xilinx_cdma_chan *chan = data; + u32 status; + + status = cdma_read(chan, XILINX_CDMA_STATUS_OFFSET); + if (!(status & XILINX_CDMA_XR_IRQ_ALL_MASK)) + return IRQ_NONE; + + /* Ack the interrupts */ + cdma_write(chan, XILINX_CDMA_STATUS_OFFSET, + XILINX_CDMA_XR_IRQ_ALL_MASK); + + if (status & XILINX_CDMA_XR_IRQ_ERROR_MASK) { + dev_err(chan->dev, + "Channel %x has errors %x, cdr %x tdr %x\n", + (u32)chan, + (u32)cdma_read(chan, XILINX_CDMA_STATUS_OFFSET), + (u32)cdma_read(chan, XILINX_CDMA_CDESC_OFFSET), + (u32)cdma_read(chan, XILINX_CDMA_TDESC_OFFSET)); + chan->err = true; + } + + /* + * Device takes too long to do the transfer when user requires + * responsiveness + */ + if (status & XILINX_CDMA_XR_IRQ_DELAY_MASK) + dev_dbg(chan->dev, "Inter-packet latency too long\n"); + + if (status & XILINX_CDMA_XR_IRQ_IOC_MASK) { + xilinx_cdma_complete_descriptor(chan); + xilinx_cdma_start_transfer(chan); + } + + tasklet_schedule(&chan->tasklet); + return IRQ_HANDLED; +} + +/** + * xilinx_cdma_do_tasklet - Schedule completion tasklet + * @data: Pointer to the Xilinx cdma channel structure + */ +static void xilinx_cdma_do_tasklet(unsigned long data) +{ + struct xilinx_cdma_chan *chan = (struct xilinx_cdma_chan *)data; + + xilinx_cdma_chan_desc_cleanup(chan); +} + +/** + * xilinx_cdma_tx_submit - Submit DMA transaction + * @tx: Async transaction descriptor + * + * Return: cookie value on success and failure value on error + */ +static dma_cookie_t xilinx_cdma_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct xilinx_cdma_chan *chan = to_xilinx_chan(tx->chan); + struct xilinx_cdma_tx_descriptor *desc = to_cdma_tx_descriptor(tx); + 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_cdma_chan_reset(chan); + if (err < 0) + return err; + } + + spin_lock_irqsave(&chan->lock, flags); + + cookie = dma_cookie_assign(tx); + + /* Append the transaction to the pending transactions queue. */ + list_add_tail(&desc->node, &chan->pending_list); + + /* Free the allocated desc */ + chan->allocated_desc = NULL; + + spin_unlock_irqrestore(&chan->lock, flags); + + return cookie; +} + +/** + * xilinx_cdma_prep_memcpy - prepare descriptors for a memcpy transaction + * @dchan: DMA channel + * @dma_dst: destination address + * @dma_src: source address + * @len: transfer length + * @flags: transfer ack flags + * + * Return: Async transaction descriptor on success and NULL on failure + */ +static struct dma_async_tx_descriptor * +xilinx_cdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst, + dma_addr_t dma_src, size_t len, unsigned long flags) +{ + struct xilinx_cdma_chan *chan = to_xilinx_chan(dchan); + struct xilinx_cdma_desc_hw *hw; + struct xilinx_cdma_tx_descriptor *desc; + struct xilinx_cdma_tx_segment *segment, *prev; + + if (!len || len > XILINX_CDMA_MAX_TRANS_LEN) + return NULL; + + desc = xilinx_cdma_alloc_tx_descriptor(chan); + if (!desc) + return NULL; + + dma_async_tx_descriptor_init(&desc->async_tx, &chan->common); + desc->async_tx.tx_submit = xilinx_cdma_tx_submit; + async_tx_ack(&desc->async_tx); + + /* Allocate the link descriptor from DMA pool */ + segment = xilinx_cdma_alloc_tx_segment(chan); + if (!segment) + goto error; + + hw = &segment->hw; + hw->control = len; + hw->src_addr = dma_src; + hw->dest_addr = dma_dst; + + /* Fill the previous next descriptor with current */ + prev = list_last_entry(&desc->segments, + struct xilinx_cdma_tx_segment, node); + prev->hw.next_desc = segment->phys; + + /* Insert the segment into the descriptor segments list. */ + list_add_tail(&segment->node, &desc->segments); + + prev = segment; + + /* Link the last hardware descriptor with the first. */ + segment = list_first_entry(&desc->segments, + struct xilinx_cdma_tx_segment, node); + prev->hw.next_desc = segment->phys; + + return &desc->async_tx; + +error: + xilinx_cdma_free_tx_descriptor(chan, desc); + return NULL; +} + +/** + * xilinx_cdma_device_control - Configure DMA channel of the device + * @dchan: DMA Channel pointer + * @cmd: DMA control command + * @arg: Channel configuration + * + * Return: '0' on success and failure value on error + */ +static int xilinx_cdma_device_control(struct dma_chan *dchan, + enum dma_ctrl_cmd cmd, unsigned long arg) +{ + struct xilinx_cdma_chan *chan = to_xilinx_chan(dchan); + unsigned long flags; + + if (cmd != DMA_TERMINATE_ALL) + return -ENXIO; + + spin_lock_irqsave(&chan->lock, flags); + + /* Remove and free all of the descriptors in the lists */ + xilinx_cdma_free_desc_list(chan, &chan->pending_list); + xilinx_cdma_free_desc_list(chan, &chan->done_list); + + spin_unlock_irqrestore(&chan->lock, flags); + + return 0; +} + +/** + * xilinx_cdma_channel_set_config - Configure cdma channel + * @dchan: DMA channel + * @cfg: cdma device configuration pointer + * + * Return: '0' on success and failure value on error + */ +int xilinx_cdma_channel_set_config(struct dma_chan *dchan, + struct xilinx_cdma_config *cfg) +{ + struct xilinx_cdma_chan *chan = to_xilinx_chan(dchan); + u32 reg = cdma_read(chan, XILINX_CDMA_CONTROL_OFFSET); + + if (!cdma_is_idle(chan)) + return -EBUSY; + + if (cfg->reset) + return xilinx_cdma_chan_reset(chan); + + if (cfg->coalesc <= XILINX_CDMA_COALESCE_MAX) { + reg &= ~XILINX_CDMA_XR_COALESCE_MASK; + reg |= cfg->coalesc << XILINX_CDMA_COALESCE_SHIFT; + } + + if (cfg->delay <= XILINX_CDMA_DELAY_MAX) { + reg &= ~XILINX_CDMA_XR_DELAY_MASK; + reg |= cfg->delay << XILINX_CDMA_DELAY_SHIFT; + } + + cdma_write(chan, XILINX_CDMA_CONTROL_OFFSET, reg); + + return 0; +} +EXPORT_SYMBOL(xilinx_cdma_channel_set_config); + +/* ----------------------------------------------------------------------------- + * Probe and remove + */ + +/** + * xilinx_cdma_free_channel - Channel remove function + * @chan: Driver specific cdma channel + */ +static void xilinx_cdma_free_channel(struct xilinx_cdma_chan *chan) +{ + /* Disable Interrupts */ + cdma_ctrl_clr(chan, XILINX_CDMA_CONTROL_OFFSET, + XILINX_CDMA_XR_IRQ_ALL_MASK); + + if (chan->irq > 0) + free_irq(chan->irq, chan); + + tasklet_kill(&chan->tasklet); + + list_del(&chan->common.device_node); +} + +/** + * xilinx_cdma_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_cdma_chan_probe(struct xilinx_cdma_device *xdev, + struct device_node *node) +{ + struct xilinx_cdma_chan *chan; + bool has_dre; + u32 value, width; + int err; + + /* Alloc channel */ + chan = devm_kzalloc(xdev->dev, sizeof(*chan), GFP_KERNEL); + if (!chan) + return -ENOMEM; + + chan->dev = xdev->dev; + chan->has_sg = xdev->has_sg; + chan->xdev = xdev; + + spin_lock_init(&chan->lock); + INIT_LIST_HEAD(&chan->pending_list); + INIT_LIST_HEAD(&chan->done_list); + + /* Retrieve the channel properties from the device tree */ + has_dre = of_property_read_bool(node, "xlnx,include-dre"); + + 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); + + /* Request the interrupt */ + chan->irq = irq_of_parse_and_map(node, 0); + err = request_irq(chan->irq, xilinx_cdma_irq_handler, IRQF_SHARED, + "xilinx-cdma-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_cdma_do_tasklet, + (unsigned long)chan); + + /* + * Initialize the DMA channel and add it to the DMA engine channels + * list. + */ + chan->common.device = &xdev->common; + + list_add_tail(&chan->common.device_node, &xdev->common.channels); + xdev->chan = chan; + + /* Initialize the channel */ + err = xilinx_cdma_chan_reset(chan); + if (err) { + dev_err(xdev->dev, "Reset channel failed\n"); + return err; + } + + return 0; +} + +/** + * of_dma_xilinx_xlate - Translation function + * @dma_spec: Pointer to DMA specifier as found in the device tree + * @ofdma: Pointer to DMA controller data + * + * Return: DMA channel pointer on success and NULL on error + */ +static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct xilinx_cdma_device *xdev = ofdma->of_dma_data; + + return dma_get_slave_channel(&xdev->chan->common); +} + +/** + * xilinx_cdma_probe - Driver probe function + * @pdev: Pointer to the platform_device structure + * + * Return: '0' on success and failure value on error + */ +static int xilinx_cdma_probe(struct platform_device *pdev) +{ + struct xilinx_cdma_device *xdev; + struct device_node *child, *node; + struct resource *res; + int 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"); + + dma_cap_set(DMA_MEMCPY, xdev->common.cap_mask); + xdev->common.device_prep_dma_memcpy = xilinx_cdma_prep_memcpy; + + xdev->common.device_control = xilinx_cdma_device_control; + xdev->common.device_issue_pending = xilinx_cdma_issue_pending; + xdev->common.device_alloc_chan_resources = + xilinx_cdma_alloc_chan_resources; + xdev->common.device_free_chan_resources = + xilinx_cdma_free_chan_resources; + xdev->common.device_tx_status = xilinx_tx_status; + xdev->common.dev = &pdev->dev; + + platform_set_drvdata(pdev, xdev); + + child = of_get_next_child(node, NULL); + if (!child) { + dev_err(&pdev->dev, "No channel found\n"); + return PTR_ERR(child); + } + + ret = xilinx_cdma_chan_probe(xdev, child); + if (ret) { + dev_err(&pdev->dev, "Probing channel 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 CDMA Engine driver Probed!!\n"); + + return 0; + +free_chan_resources: + xilinx_cdma_free_channel(xdev->chan); + + return ret; +} + +/** + * xilinx_cdma_remove - Driver remove function + * @pdev: Pointer to the platform_device structure + * + * Return: Always '0' + */ +static int xilinx_cdma_remove(struct platform_device *pdev) +{ + struct xilinx_cdma_device *xdev = platform_get_drvdata(pdev); + + of_dma_controller_free(pdev->dev.of_node); + dma_async_device_unregister(&xdev->common); + + xilinx_cdma_free_channel(xdev->chan); + + return 0; +} + +static const struct of_device_id xilinx_cdma_of_match[] = { + { .compatible = "xlnx,axi-cdma-1.00.a", }, + {} +}; +MODULE_DEVICE_TABLE(of, xilinx_cdma_of_match); + +static struct platform_driver xilinx_cdma_driver = { + .driver = { + .name = "xilinx-cdma", + .owner = THIS_MODULE, + .of_match_table = xilinx_cdma_of_match, + }, + .probe = xilinx_cdma_probe, + .remove = xilinx_cdma_remove, +}; + +module_platform_driver(xilinx_cdma_driver); + +MODULE_AUTHOR("Xilinx, Inc."); +MODULE_DESCRIPTION("Xilinx CDMA driver"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/dma/xilinx_dma.h b/include/linux/dma/xilinx_dma.h index 34b98f2..fb74ff7 100644 --- a/include/linux/dma/xilinx_dma.h +++ b/include/linux/dma/xilinx_dma.h @@ -41,7 +41,20 @@ struct xilinx_vdma_config { int ext_fsync; }; +/** + * struct xilinx_cdma_config - CDMA Configuration structure + * @coalesc: Interrupt coalescing threshold + * @delay: Delay counter + * @reset: Reset Channel + */ +struct xilinx_cdma_config { + int coalesc; + int delay; + int reset; +}; + int xilinx_vdma_channel_set_config(struct dma_chan *dchan, struct xilinx_vdma_config *cfg); - +int xilinx_cdma_channel_set_config(struct dma_chan *dchan, + struct xilinx_cdma_config *cfg); #endif