diff options
Diffstat (limited to 'drivers/dma/dma-axi-dmac.c')
| -rw-r--r-- | drivers/dma/dma-axi-dmac.c | 691 |
1 files changed, 691 insertions, 0 deletions
diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c new file mode 100644 index 000000000..5b2395e7e --- /dev/null +++ b/drivers/dma/dma-axi-dmac.c @@ -0,0 +1,691 @@ +/* + * Driver for the Analog Devices AXI-DMAC core + * + * Copyright 2013-2015 Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * Licensed under the GPL-2. + */ + +#include <linux/clk.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_dma.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include <dt-bindings/dma/axi-dmac.h> + +#include "dmaengine.h" +#include "virt-dma.h" + +/* + * The AXI-DMAC is a soft IP core that is used in FPGA designs. The core has + * various instantiation parameters which decided the exact feature set support + * by the core. + * + * Each channel of the core has a source interface and a destination interface. + * The number of channels and the type of the channel interfaces is selected at + * configuration time. A interface can either be a connected to a central memory + * interconnect, which allows access to system memory, or it can be connected to + * a dedicated bus which is directly connected to a data port on a peripheral. + * Given that those are configuration options of the core that are selected when + * it is instantiated this means that they can not be changed by software at + * runtime. By extension this means that each channel is uni-directional. It can + * either be device to memory or memory to device, but not both. Also since the + * device side is a dedicated data bus only connected to a single peripheral + * there is no address than can or needs to be configured for the device side. + */ + +#define AXI_DMAC_REG_IRQ_MASK 0x80 +#define AXI_DMAC_REG_IRQ_PENDING 0x84 +#define AXI_DMAC_REG_IRQ_SOURCE 0x88 + +#define AXI_DMAC_REG_CTRL 0x400 +#define AXI_DMAC_REG_TRANSFER_ID 0x404 +#define AXI_DMAC_REG_START_TRANSFER 0x408 +#define AXI_DMAC_REG_FLAGS 0x40c +#define AXI_DMAC_REG_DEST_ADDRESS 0x410 +#define AXI_DMAC_REG_SRC_ADDRESS 0x414 +#define AXI_DMAC_REG_X_LENGTH 0x418 +#define AXI_DMAC_REG_Y_LENGTH 0x41c +#define AXI_DMAC_REG_DEST_STRIDE 0x420 +#define AXI_DMAC_REG_SRC_STRIDE 0x424 +#define AXI_DMAC_REG_TRANSFER_DONE 0x428 +#define AXI_DMAC_REG_ACTIVE_TRANSFER_ID 0x42c +#define AXI_DMAC_REG_STATUS 0x430 +#define AXI_DMAC_REG_CURRENT_SRC_ADDR 0x434 +#define AXI_DMAC_REG_CURRENT_DEST_ADDR 0x438 + +#define AXI_DMAC_CTRL_ENABLE BIT(0) +#define AXI_DMAC_CTRL_PAUSE BIT(1) + +#define AXI_DMAC_IRQ_SOT BIT(0) +#define AXI_DMAC_IRQ_EOT BIT(1) + +#define AXI_DMAC_FLAG_CYCLIC BIT(0) + +struct axi_dmac_sg { + dma_addr_t src_addr; + dma_addr_t dest_addr; + unsigned int x_len; + unsigned int y_len; + unsigned int dest_stride; + unsigned int src_stride; + unsigned int id; +}; + +struct axi_dmac_desc { + struct virt_dma_desc vdesc; + bool cyclic; + + unsigned int num_submitted; + unsigned int num_completed; + unsigned int num_sgs; + struct axi_dmac_sg sg[]; +}; + +struct axi_dmac_chan { + struct virt_dma_chan vchan; + + struct axi_dmac_desc *next_desc; + struct list_head active_descs; + enum dma_transfer_direction direction; + + unsigned int src_width; + unsigned int dest_width; + unsigned int src_type; + unsigned int dest_type; + + unsigned int max_length; + unsigned int align_mask; + + bool hw_cyclic; + bool hw_2d; +}; + +struct axi_dmac { + void __iomem *base; + int irq; + + struct clk *clk; + + struct dma_device dma_dev; + struct axi_dmac_chan chan; + + struct device_dma_parameters dma_parms; +}; + +static struct axi_dmac *chan_to_axi_dmac(struct axi_dmac_chan *chan) +{ + return container_of(chan->vchan.chan.device, struct axi_dmac, + dma_dev); +} + +static struct axi_dmac_chan *to_axi_dmac_chan(struct dma_chan *c) +{ + return container_of(c, struct axi_dmac_chan, vchan.chan); +} + +static struct axi_dmac_desc *to_axi_dmac_desc(struct virt_dma_desc *vdesc) +{ + return container_of(vdesc, struct axi_dmac_desc, vdesc); +} + +static void axi_dmac_write(struct axi_dmac *axi_dmac, unsigned int reg, + unsigned int val) +{ + writel(val, axi_dmac->base + reg); +} + +static int axi_dmac_read(struct axi_dmac *axi_dmac, unsigned int reg) +{ + return readl(axi_dmac->base + reg); +} + +static int axi_dmac_src_is_mem(struct axi_dmac_chan *chan) +{ + return chan->src_type == AXI_DMAC_BUS_TYPE_AXI_MM; +} + +static int axi_dmac_dest_is_mem(struct axi_dmac_chan *chan) +{ + return chan->dest_type == AXI_DMAC_BUS_TYPE_AXI_MM; +} + +static bool axi_dmac_check_len(struct axi_dmac_chan *chan, unsigned int len) +{ + if (len == 0 || len > chan->max_length) + return false; + if ((len & chan->align_mask) != 0) /* Not aligned */ + return false; + return true; +} + +static bool axi_dmac_check_addr(struct axi_dmac_chan *chan, dma_addr_t addr) +{ + if ((addr & chan->align_mask) != 0) /* Not aligned */ + return false; + return true; +} + +static void axi_dmac_start_transfer(struct axi_dmac_chan *chan) +{ + struct axi_dmac *dmac = chan_to_axi_dmac(chan); + struct virt_dma_desc *vdesc; + struct axi_dmac_desc *desc; + struct axi_dmac_sg *sg; + unsigned int flags = 0; + unsigned int val; + + val = axi_dmac_read(dmac, AXI_DMAC_REG_START_TRANSFER); + if (val) /* Queue is full, wait for the next SOT IRQ */ + return; + + desc = chan->next_desc; + + if (!desc) { + vdesc = vchan_next_desc(&chan->vchan); + if (!vdesc) + return; + list_move_tail(&vdesc->node, &chan->active_descs); + desc = to_axi_dmac_desc(vdesc); + } + sg = &desc->sg[desc->num_submitted]; + + desc->num_submitted++; + if (desc->num_submitted == desc->num_sgs) + chan->next_desc = NULL; + else + chan->next_desc = desc; + + sg->id = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_ID); + + if (axi_dmac_dest_is_mem(chan)) { + axi_dmac_write(dmac, AXI_DMAC_REG_DEST_ADDRESS, sg->dest_addr); + axi_dmac_write(dmac, AXI_DMAC_REG_DEST_STRIDE, sg->dest_stride); + } + + if (axi_dmac_src_is_mem(chan)) { + axi_dmac_write(dmac, AXI_DMAC_REG_SRC_ADDRESS, sg->src_addr); + axi_dmac_write(dmac, AXI_DMAC_REG_SRC_STRIDE, sg->src_stride); + } + + /* + * If the hardware supports cyclic transfers and there is no callback to + * call, enable hw cyclic mode to avoid unnecessary interrupts. + */ + if (chan->hw_cyclic && desc->cyclic && !desc->vdesc.tx.callback) + flags |= AXI_DMAC_FLAG_CYCLIC; + + axi_dmac_write(dmac, AXI_DMAC_REG_X_LENGTH, sg->x_len - 1); + axi_dmac_write(dmac, AXI_DMAC_REG_Y_LENGTH, sg->y_len - 1); + axi_dmac_write(dmac, AXI_DMAC_REG_FLAGS, flags); + axi_dmac_write(dmac, AXI_DMAC_REG_START_TRANSFER, 1); +} + +static struct axi_dmac_desc *axi_dmac_active_desc(struct axi_dmac_chan *chan) +{ + return list_first_entry_or_null(&chan->active_descs, + struct axi_dmac_desc, vdesc.node); +} + +static void axi_dmac_transfer_done(struct axi_dmac_chan *chan, + unsigned int completed_transfers) +{ + struct axi_dmac_desc *active; + struct axi_dmac_sg *sg; + + active = axi_dmac_active_desc(chan); + if (!active) + return; + + if (active->cyclic) { + vchan_cyclic_callback(&active->vdesc); + } else { + do { + sg = &active->sg[active->num_completed]; + if (!(BIT(sg->id) & completed_transfers)) + break; + active->num_completed++; + if (active->num_completed == active->num_sgs) { + list_del(&active->vdesc.node); + vchan_cookie_complete(&active->vdesc); + active = axi_dmac_active_desc(chan); + } + } while (active); + } +} + +static irqreturn_t axi_dmac_interrupt_handler(int irq, void *devid) +{ + struct axi_dmac *dmac = devid; + unsigned int pending; + + pending = axi_dmac_read(dmac, AXI_DMAC_REG_IRQ_PENDING); + axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_PENDING, pending); + + spin_lock(&dmac->chan.vchan.lock); + /* One or more transfers have finished */ + if (pending & AXI_DMAC_IRQ_EOT) { + unsigned int completed; + + completed = axi_dmac_read(dmac, AXI_DMAC_REG_TRANSFER_DONE); + axi_dmac_transfer_done(&dmac->chan, completed); + } + /* Space has become available in the descriptor queue */ + if (pending & AXI_DMAC_IRQ_SOT) + axi_dmac_start_transfer(&dmac->chan); + spin_unlock(&dmac->chan.vchan.lock); + + return IRQ_HANDLED; +} + +static int axi_dmac_terminate_all(struct dma_chan *c) +{ + struct axi_dmac_chan *chan = to_axi_dmac_chan(c); + struct axi_dmac *dmac = chan_to_axi_dmac(chan); + unsigned long flags; + LIST_HEAD(head); + + spin_lock_irqsave(&chan->vchan.lock, flags); + axi_dmac_write(dmac, AXI_DMAC_REG_CTRL, 0); + chan->next_desc = NULL; + vchan_get_all_descriptors(&chan->vchan, &head); + list_splice_tail_init(&chan->active_descs, &head); + spin_unlock_irqrestore(&chan->vchan.lock, flags); + + vchan_dma_desc_free_list(&chan->vchan, &head); + + return 0; +} + +static void axi_dmac_issue_pending(struct dma_chan *c) +{ + struct axi_dmac_chan *chan = to_axi_dmac_chan(c); + struct axi_dmac *dmac = chan_to_axi_dmac(chan); + unsigned long flags; + + axi_dmac_write(dmac, AXI_DMAC_REG_CTRL, AXI_DMAC_CTRL_ENABLE); + + spin_lock_irqsave(&chan->vchan.lock, flags); + if (vchan_issue_pending(&chan->vchan)) + axi_dmac_start_transfer(chan); + spin_unlock_irqrestore(&chan->vchan.lock, flags); +} + +static struct axi_dmac_desc *axi_dmac_alloc_desc(unsigned int num_sgs) +{ + struct axi_dmac_desc *desc; + + desc = kzalloc(sizeof(struct axi_dmac_desc) + + sizeof(struct axi_dmac_sg) * num_sgs, GFP_NOWAIT); + if (!desc) + return NULL; + + desc->num_sgs = num_sgs; + + return desc; +} + +static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg( + struct dma_chan *c, struct scatterlist *sgl, + unsigned int sg_len, enum dma_transfer_direction direction, + unsigned long flags, void *context) +{ + struct axi_dmac_chan *chan = to_axi_dmac_chan(c); + struct axi_dmac_desc *desc; + struct scatterlist *sg; + unsigned int i; + + if (direction != chan->direction) + return NULL; + + desc = axi_dmac_alloc_desc(sg_len); + if (!desc) + return NULL; + + for_each_sg(sgl, sg, sg_len, i) { + if (!axi_dmac_check_addr(chan, sg_dma_address(sg)) || + !axi_dmac_check_len(chan, sg_dma_len(sg))) { + kfree(desc); + return NULL; + } + + if (direction == DMA_DEV_TO_MEM) + desc->sg[i].dest_addr = sg_dma_address(sg); + else + desc->sg[i].src_addr = sg_dma_address(sg); + desc->sg[i].x_len = sg_dma_len(sg); + desc->sg[i].y_len = 1; + } + + desc->cyclic = false; + + return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); +} + +static struct dma_async_tx_descriptor *axi_dmac_prep_dma_cyclic( + struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len, + size_t period_len, enum dma_transfer_direction direction, + unsigned long flags) +{ + struct axi_dmac_chan *chan = to_axi_dmac_chan(c); + struct axi_dmac_desc *desc; + unsigned int num_periods, i; + + if (direction != chan->direction) + return NULL; + + if (!axi_dmac_check_len(chan, buf_len) || + !axi_dmac_check_addr(chan, buf_addr)) + return NULL; + + if (period_len == 0 || buf_len % period_len) + return NULL; + + num_periods = buf_len / period_len; + + desc = axi_dmac_alloc_desc(num_periods); + if (!desc) + return NULL; + + for (i = 0; i < num_periods; i++) { + if (direction == DMA_DEV_TO_MEM) + desc->sg[i].dest_addr = buf_addr; + else + desc->sg[i].src_addr = buf_addr; + desc->sg[i].x_len = period_len; + desc->sg[i].y_len = 1; + buf_addr += period_len; + } + + desc->cyclic = true; + + return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); +} + +static struct dma_async_tx_descriptor *axi_dmac_prep_interleaved( + struct dma_chan *c, struct dma_interleaved_template *xt, + unsigned long flags) +{ + struct axi_dmac_chan *chan = to_axi_dmac_chan(c); + struct axi_dmac_desc *desc; + size_t dst_icg, src_icg; + + if (xt->frame_size != 1) + return NULL; + + if (xt->dir != chan->direction) + return NULL; + + if (axi_dmac_src_is_mem(chan)) { + if (!xt->src_inc || !axi_dmac_check_addr(chan, xt->src_start)) + return NULL; + } + + if (axi_dmac_dest_is_mem(chan)) { + if (!xt->dst_inc || !axi_dmac_check_addr(chan, xt->dst_start)) + return NULL; + } + + dst_icg = dmaengine_get_dst_icg(xt, &xt->sgl[0]); + src_icg = dmaengine_get_src_icg(xt, &xt->sgl[0]); + + if (chan->hw_2d) { + if (!axi_dmac_check_len(chan, xt->sgl[0].size) || + !axi_dmac_check_len(chan, xt->numf)) + return NULL; + if (xt->sgl[0].size + dst_icg > chan->max_length || + xt->sgl[0].size + src_icg > chan->max_length) + return NULL; + } else { + if (dst_icg != 0 || src_icg != 0) + return NULL; + if (chan->max_length / xt->sgl[0].size < xt->numf) + return NULL; + if (!axi_dmac_check_len(chan, xt->sgl[0].size * xt->numf)) + return NULL; + } + + desc = axi_dmac_alloc_desc(1); + if (!desc) + return NULL; + + if (axi_dmac_src_is_mem(chan)) { + desc->sg[0].src_addr = xt->src_start; + desc->sg[0].src_stride = xt->sgl[0].size + src_icg; + } + + if (axi_dmac_dest_is_mem(chan)) { + desc->sg[0].dest_addr = xt->dst_start; + desc->sg[0].dest_stride = xt->sgl[0].size + dst_icg; + } + + if (chan->hw_2d) { + desc->sg[0].x_len = xt->sgl[0].size; + desc->sg[0].y_len = xt->numf; + } else { + desc->sg[0].x_len = xt->sgl[0].size * xt->numf; + desc->sg[0].y_len = 1; + } + + return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); +} + +static void axi_dmac_free_chan_resources(struct dma_chan *c) +{ + vchan_free_chan_resources(to_virt_chan(c)); +} + +static void axi_dmac_desc_free(struct virt_dma_desc *vdesc) +{ + kfree(container_of(vdesc, struct axi_dmac_desc, vdesc)); +} + +/* + * The configuration stored in the devicetree matches the configuration + * parameters of the peripheral instance and allows the driver to know which + * features are implemented and how it should behave. + */ +static int axi_dmac_parse_chan_dt(struct device_node *of_chan, + struct axi_dmac_chan *chan) +{ + u32 val; + int ret; + + ret = of_property_read_u32(of_chan, "reg", &val); + if (ret) + return ret; + + /* We only support 1 channel for now */ + if (val != 0) + return -EINVAL; + + ret = of_property_read_u32(of_chan, "adi,source-bus-type", &val); + if (ret) + return ret; + if (val > AXI_DMAC_BUS_TYPE_FIFO) + return -EINVAL; + chan->src_type = val; + + ret = of_property_read_u32(of_chan, "adi,destination-bus-type", &val); + if (ret) + return ret; + if (val > AXI_DMAC_BUS_TYPE_FIFO) + return -EINVAL; + chan->dest_type = val; + + ret = of_property_read_u32(of_chan, "adi,source-bus-width", &val); + if (ret) + return ret; + chan->src_width = val / 8; + + ret = of_property_read_u32(of_chan, "adi,destination-bus-width", &val); + if (ret) + return ret; + chan->dest_width = val / 8; + + ret = of_property_read_u32(of_chan, "adi,length-width", &val); + if (ret) + return ret; + + if (val >= 32) + chan->max_length = UINT_MAX; + else + chan->max_length = (1ULL << val) - 1; + + chan->align_mask = max(chan->dest_width, chan->src_width) - 1; + + if (axi_dmac_dest_is_mem(chan) && axi_dmac_src_is_mem(chan)) + chan->direction = DMA_MEM_TO_MEM; + else if (!axi_dmac_dest_is_mem(chan) && axi_dmac_src_is_mem(chan)) + chan->direction = DMA_MEM_TO_DEV; + else if (axi_dmac_dest_is_mem(chan) && !axi_dmac_src_is_mem(chan)) + chan->direction = DMA_DEV_TO_MEM; + else + chan->direction = DMA_DEV_TO_DEV; + + chan->hw_cyclic = of_property_read_bool(of_chan, "adi,cyclic"); + chan->hw_2d = of_property_read_bool(of_chan, "adi,2d"); + + return 0; +} + +static int axi_dmac_probe(struct platform_device *pdev) +{ + struct device_node *of_channels, *of_chan; + struct dma_device *dma_dev; + struct axi_dmac *dmac; + struct resource *res; + int ret; + + dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL); + if (!dmac) + return -ENOMEM; + + dmac->irq = platform_get_irq(pdev, 0); + if (dmac->irq <= 0) + return -EINVAL; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dmac->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(dmac->base)) + return PTR_ERR(dmac->base); + + dmac->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(dmac->clk)) + return PTR_ERR(dmac->clk); + + INIT_LIST_HEAD(&dmac->chan.active_descs); + + of_channels = of_get_child_by_name(pdev->dev.of_node, "adi,channels"); + if (of_channels == NULL) + return -ENODEV; + + for_each_child_of_node(of_channels, of_chan) { + ret = axi_dmac_parse_chan_dt(of_chan, &dmac->chan); + if (ret) { + of_node_put(of_chan); + of_node_put(of_channels); + return -EINVAL; + } + } + of_node_put(of_channels); + + pdev->dev.dma_parms = &dmac->dma_parms; + dma_set_max_seg_size(&pdev->dev, dmac->chan.max_length); + + dma_dev = &dmac->dma_dev; + dma_cap_set(DMA_SLAVE, dma_dev->cap_mask); + dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask); + dma_dev->device_free_chan_resources = axi_dmac_free_chan_resources; + dma_dev->device_tx_status = dma_cookie_status; + dma_dev->device_issue_pending = axi_dmac_issue_pending; + dma_dev->device_prep_slave_sg = axi_dmac_prep_slave_sg; + dma_dev->device_prep_dma_cyclic = axi_dmac_prep_dma_cyclic; + dma_dev->device_prep_interleaved_dma = axi_dmac_prep_interleaved; + dma_dev->device_terminate_all = axi_dmac_terminate_all; + dma_dev->dev = &pdev->dev; + dma_dev->chancnt = 1; + dma_dev->src_addr_widths = BIT(dmac->chan.src_width); + dma_dev->dst_addr_widths = BIT(dmac->chan.dest_width); + dma_dev->directions = BIT(dmac->chan.direction); + dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; + INIT_LIST_HEAD(&dma_dev->channels); + + dmac->chan.vchan.desc_free = axi_dmac_desc_free; + vchan_init(&dmac->chan.vchan, dma_dev); + + ret = clk_prepare_enable(dmac->clk); + if (ret < 0) + return ret; + + axi_dmac_write(dmac, AXI_DMAC_REG_IRQ_MASK, 0x00); + + ret = dma_async_device_register(dma_dev); + if (ret) + goto err_clk_disable; + + ret = of_dma_controller_register(pdev->dev.of_node, + of_dma_xlate_by_chan_id, dma_dev); + if (ret) + goto err_unregister_device; + + ret = request_irq(dmac->irq, axi_dmac_interrupt_handler, 0, + dev_name(&pdev->dev), dmac); + if (ret) + goto err_unregister_of; + + platform_set_drvdata(pdev, dmac); + + return 0; + +err_unregister_of: + of_dma_controller_free(pdev->dev.of_node); +err_unregister_device: + dma_async_device_unregister(&dmac->dma_dev); +err_clk_disable: + clk_disable_unprepare(dmac->clk); + + return ret; +} + +static int axi_dmac_remove(struct platform_device *pdev) +{ + struct axi_dmac *dmac = platform_get_drvdata(pdev); + + of_dma_controller_free(pdev->dev.of_node); + free_irq(dmac->irq, dmac); + tasklet_kill(&dmac->chan.vchan.task); + dma_async_device_unregister(&dmac->dma_dev); + clk_disable_unprepare(dmac->clk); + + return 0; +} + +static const struct of_device_id axi_dmac_of_match_table[] = { + { .compatible = "adi,axi-dmac-1.00.a" }, + { }, +}; + +static struct platform_driver axi_dmac_driver = { + .driver = { + .name = "dma-axi-dmac", + .of_match_table = axi_dmac_of_match_table, + }, + .probe = axi_dmac_probe, + .remove = axi_dmac_remove, +}; +module_platform_driver(axi_dmac_driver); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("DMA controller driver for the AXI-DMAC controller"); +MODULE_LICENSE("GPL v2"); |