/* * 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_synchronize(struct dma_chan *c) { struct axi_dmac_chan *chan = to_axi_dmac_chan(c); vchan_synchronize(&chan->vchan); } 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->device_synchronize = axi_dmac_synchronize; 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");