/* * Copyright (C) 2013, Lars-Peter Clausen <lars@metafoo.de> * JZ4740 DMAC support * * 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 <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/err.h> #include <linux/init.h> #include <linux/list.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/irq.h> #include <linux/clk.h> #include "virt-dma.h" #define JZ_DMA_NR_CHANS 6 #define JZ_REG_DMA_SRC_ADDR(x) (0x00 + (x) * 0x20) #define JZ_REG_DMA_DST_ADDR(x) (0x04 + (x) * 0x20) #define JZ_REG_DMA_TRANSFER_COUNT(x) (0x08 + (x) * 0x20) #define JZ_REG_DMA_REQ_TYPE(x) (0x0C + (x) * 0x20) #define JZ_REG_DMA_STATUS_CTRL(x) (0x10 + (x) * 0x20) #define JZ_REG_DMA_CMD(x) (0x14 + (x) * 0x20) #define JZ_REG_DMA_DESC_ADDR(x) (0x18 + (x) * 0x20) #define JZ_REG_DMA_CTRL 0x300 #define JZ_REG_DMA_IRQ 0x304 #define JZ_REG_DMA_DOORBELL 0x308 #define JZ_REG_DMA_DOORBELL_SET 0x30C #define JZ_DMA_STATUS_CTRL_NO_DESC BIT(31) #define JZ_DMA_STATUS_CTRL_DESC_INV BIT(6) #define JZ_DMA_STATUS_CTRL_ADDR_ERR BIT(4) #define JZ_DMA_STATUS_CTRL_TRANSFER_DONE BIT(3) #define JZ_DMA_STATUS_CTRL_HALT BIT(2) #define JZ_DMA_STATUS_CTRL_COUNT_TERMINATE BIT(1) #define JZ_DMA_STATUS_CTRL_ENABLE BIT(0) #define JZ_DMA_CMD_SRC_INC BIT(23) #define JZ_DMA_CMD_DST_INC BIT(22) #define JZ_DMA_CMD_RDIL_MASK (0xf << 16) #define JZ_DMA_CMD_SRC_WIDTH_MASK (0x3 << 14) #define JZ_DMA_CMD_DST_WIDTH_MASK (0x3 << 12) #define JZ_DMA_CMD_INTERVAL_LENGTH_MASK (0x7 << 8) #define JZ_DMA_CMD_BLOCK_MODE BIT(7) #define JZ_DMA_CMD_DESC_VALID BIT(4) #define JZ_DMA_CMD_DESC_VALID_MODE BIT(3) #define JZ_DMA_CMD_VALID_IRQ_ENABLE BIT(2) #define JZ_DMA_CMD_TRANSFER_IRQ_ENABLE BIT(1) #define JZ_DMA_CMD_LINK_ENABLE BIT(0) #define JZ_DMA_CMD_FLAGS_OFFSET 22 #define JZ_DMA_CMD_RDIL_OFFSET 16 #define JZ_DMA_CMD_SRC_WIDTH_OFFSET 14 #define JZ_DMA_CMD_DST_WIDTH_OFFSET 12 #define JZ_DMA_CMD_TRANSFER_SIZE_OFFSET 8 #define JZ_DMA_CMD_MODE_OFFSET 7 #define JZ_DMA_CTRL_PRIORITY_MASK (0x3 << 8) #define JZ_DMA_CTRL_HALT BIT(3) #define JZ_DMA_CTRL_ADDRESS_ERROR BIT(2) #define JZ_DMA_CTRL_ENABLE BIT(0) enum jz4740_dma_width { JZ4740_DMA_WIDTH_32BIT = 0, JZ4740_DMA_WIDTH_8BIT = 1, JZ4740_DMA_WIDTH_16BIT = 2, }; enum jz4740_dma_transfer_size { JZ4740_DMA_TRANSFER_SIZE_4BYTE = 0, JZ4740_DMA_TRANSFER_SIZE_1BYTE = 1, JZ4740_DMA_TRANSFER_SIZE_2BYTE = 2, JZ4740_DMA_TRANSFER_SIZE_16BYTE = 3, JZ4740_DMA_TRANSFER_SIZE_32BYTE = 4, }; enum jz4740_dma_flags { JZ4740_DMA_SRC_AUTOINC = 0x2, JZ4740_DMA_DST_AUTOINC = 0x1, }; enum jz4740_dma_mode { JZ4740_DMA_MODE_SINGLE = 0, JZ4740_DMA_MODE_BLOCK = 1, }; struct jz4740_dma_sg { dma_addr_t addr; unsigned int len; }; struct jz4740_dma_desc { struct virt_dma_desc vdesc; enum dma_transfer_direction direction; bool cyclic; unsigned int num_sgs; struct jz4740_dma_sg sg[]; }; struct jz4740_dmaengine_chan { struct virt_dma_chan vchan; unsigned int id; dma_addr_t fifo_addr; unsigned int transfer_shift; struct jz4740_dma_desc *desc; unsigned int next_sg; }; struct jz4740_dma_dev { struct dma_device ddev; void __iomem *base; struct clk *clk; struct jz4740_dmaengine_chan chan[JZ_DMA_NR_CHANS]; }; static struct jz4740_dma_dev *jz4740_dma_chan_get_dev( struct jz4740_dmaengine_chan *chan) { return container_of(chan->vchan.chan.device, struct jz4740_dma_dev, ddev); } static struct jz4740_dmaengine_chan *to_jz4740_dma_chan(struct dma_chan *c) { return container_of(c, struct jz4740_dmaengine_chan, vchan.chan); } static struct jz4740_dma_desc *to_jz4740_dma_desc(struct virt_dma_desc *vdesc) { return container_of(vdesc, struct jz4740_dma_desc, vdesc); } static inline uint32_t jz4740_dma_read(struct jz4740_dma_dev *dmadev, unsigned int reg) { return readl(dmadev->base + reg); } static inline void jz4740_dma_write(struct jz4740_dma_dev *dmadev, unsigned reg, uint32_t val) { writel(val, dmadev->base + reg); } static inline void jz4740_dma_write_mask(struct jz4740_dma_dev *dmadev, unsigned int reg, uint32_t val, uint32_t mask) { uint32_t tmp; tmp = jz4740_dma_read(dmadev, reg); tmp &= ~mask; tmp |= val; jz4740_dma_write(dmadev, reg, tmp); } static struct jz4740_dma_desc *jz4740_dma_alloc_desc(unsigned int num_sgs) { return kzalloc(sizeof(struct jz4740_dma_desc) + sizeof(struct jz4740_dma_sg) * num_sgs, GFP_ATOMIC); } static enum jz4740_dma_width jz4740_dma_width(enum dma_slave_buswidth width) { switch (width) { case DMA_SLAVE_BUSWIDTH_1_BYTE: return JZ4740_DMA_WIDTH_8BIT; case DMA_SLAVE_BUSWIDTH_2_BYTES: return JZ4740_DMA_WIDTH_16BIT; case DMA_SLAVE_BUSWIDTH_4_BYTES: return JZ4740_DMA_WIDTH_32BIT; default: return JZ4740_DMA_WIDTH_32BIT; } } static enum jz4740_dma_transfer_size jz4740_dma_maxburst(u32 maxburst) { if (maxburst <= 1) return JZ4740_DMA_TRANSFER_SIZE_1BYTE; else if (maxburst <= 3) return JZ4740_DMA_TRANSFER_SIZE_2BYTE; else if (maxburst <= 15) return JZ4740_DMA_TRANSFER_SIZE_4BYTE; else if (maxburst <= 31) return JZ4740_DMA_TRANSFER_SIZE_16BYTE; return JZ4740_DMA_TRANSFER_SIZE_32BYTE; } static int jz4740_dma_slave_config(struct dma_chan *c, struct dma_slave_config *config) { struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c); struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan); enum jz4740_dma_width src_width; enum jz4740_dma_width dst_width; enum jz4740_dma_transfer_size transfer_size; enum jz4740_dma_flags flags; uint32_t cmd; switch (config->direction) { case DMA_MEM_TO_DEV: flags = JZ4740_DMA_SRC_AUTOINC; transfer_size = jz4740_dma_maxburst(config->dst_maxburst); chan->fifo_addr = config->dst_addr; break; case DMA_DEV_TO_MEM: flags = JZ4740_DMA_DST_AUTOINC; transfer_size = jz4740_dma_maxburst(config->src_maxburst); chan->fifo_addr = config->src_addr; break; default: return -EINVAL; } src_width = jz4740_dma_width(config->src_addr_width); dst_width = jz4740_dma_width(config->dst_addr_width); switch (transfer_size) { case JZ4740_DMA_TRANSFER_SIZE_2BYTE: chan->transfer_shift = 1; break; case JZ4740_DMA_TRANSFER_SIZE_4BYTE: chan->transfer_shift = 2; break; case JZ4740_DMA_TRANSFER_SIZE_16BYTE: chan->transfer_shift = 4; break; case JZ4740_DMA_TRANSFER_SIZE_32BYTE: chan->transfer_shift = 5; break; default: chan->transfer_shift = 0; break; } cmd = flags << JZ_DMA_CMD_FLAGS_OFFSET; cmd |= src_width << JZ_DMA_CMD_SRC_WIDTH_OFFSET; cmd |= dst_width << JZ_DMA_CMD_DST_WIDTH_OFFSET; cmd |= transfer_size << JZ_DMA_CMD_TRANSFER_SIZE_OFFSET; cmd |= JZ4740_DMA_MODE_SINGLE << JZ_DMA_CMD_MODE_OFFSET; cmd |= JZ_DMA_CMD_TRANSFER_IRQ_ENABLE; jz4740_dma_write(dmadev, JZ_REG_DMA_CMD(chan->id), cmd); jz4740_dma_write(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0); jz4740_dma_write(dmadev, JZ_REG_DMA_REQ_TYPE(chan->id), config->slave_id); return 0; } static int jz4740_dma_terminate_all(struct dma_chan *c) { struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c); struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan); unsigned long flags; LIST_HEAD(head); spin_lock_irqsave(&chan->vchan.lock, flags); jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0, JZ_DMA_STATUS_CTRL_ENABLE); chan->desc = NULL; vchan_get_all_descriptors(&chan->vchan, &head); spin_unlock_irqrestore(&chan->vchan.lock, flags); vchan_dma_desc_free_list(&chan->vchan, &head); return 0; } static int jz4740_dma_start_transfer(struct jz4740_dmaengine_chan *chan) { struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan); dma_addr_t src_addr, dst_addr; struct virt_dma_desc *vdesc; struct jz4740_dma_sg *sg; jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), 0, JZ_DMA_STATUS_CTRL_ENABLE); if (!chan->desc) { vdesc = vchan_next_desc(&chan->vchan); if (!vdesc) return 0; chan->desc = to_jz4740_dma_desc(vdesc); chan->next_sg = 0; } if (chan->next_sg == chan->desc->num_sgs) chan->next_sg = 0; sg = &chan->desc->sg[chan->next_sg]; if (chan->desc->direction == DMA_MEM_TO_DEV) { src_addr = sg->addr; dst_addr = chan->fifo_addr; } else { src_addr = chan->fifo_addr; dst_addr = sg->addr; } jz4740_dma_write(dmadev, JZ_REG_DMA_SRC_ADDR(chan->id), src_addr); jz4740_dma_write(dmadev, JZ_REG_DMA_DST_ADDR(chan->id), dst_addr); jz4740_dma_write(dmadev, JZ_REG_DMA_TRANSFER_COUNT(chan->id), sg->len >> chan->transfer_shift); chan->next_sg++; jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(chan->id), JZ_DMA_STATUS_CTRL_NO_DESC | JZ_DMA_STATUS_CTRL_ENABLE, JZ_DMA_STATUS_CTRL_HALT | JZ_DMA_STATUS_CTRL_NO_DESC | JZ_DMA_STATUS_CTRL_ENABLE); jz4740_dma_write_mask(dmadev, JZ_REG_DMA_CTRL, JZ_DMA_CTRL_ENABLE, JZ_DMA_CTRL_HALT | JZ_DMA_CTRL_ENABLE); return 0; } static void jz4740_dma_chan_irq(struct jz4740_dmaengine_chan *chan) { spin_lock(&chan->vchan.lock); if (chan->desc) { if (chan->desc->cyclic) { vchan_cyclic_callback(&chan->desc->vdesc); } else { if (chan->next_sg == chan->desc->num_sgs) { list_del(&chan->desc->vdesc.node); vchan_cookie_complete(&chan->desc->vdesc); chan->desc = NULL; } } } jz4740_dma_start_transfer(chan); spin_unlock(&chan->vchan.lock); } static irqreturn_t jz4740_dma_irq(int irq, void *devid) { struct jz4740_dma_dev *dmadev = devid; uint32_t irq_status; unsigned int i; irq_status = readl(dmadev->base + JZ_REG_DMA_IRQ); for (i = 0; i < 6; ++i) { if (irq_status & (1 << i)) { jz4740_dma_write_mask(dmadev, JZ_REG_DMA_STATUS_CTRL(i), 0, JZ_DMA_STATUS_CTRL_ENABLE | JZ_DMA_STATUS_CTRL_TRANSFER_DONE); jz4740_dma_chan_irq(&dmadev->chan[i]); } } return IRQ_HANDLED; } static void jz4740_dma_issue_pending(struct dma_chan *c) { struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c); unsigned long flags; spin_lock_irqsave(&chan->vchan.lock, flags); if (vchan_issue_pending(&chan->vchan) && !chan->desc) jz4740_dma_start_transfer(chan); spin_unlock_irqrestore(&chan->vchan.lock, flags); } static struct dma_async_tx_descriptor *jz4740_dma_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 jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c); struct jz4740_dma_desc *desc; struct scatterlist *sg; unsigned int i; desc = jz4740_dma_alloc_desc(sg_len); if (!desc) return NULL; for_each_sg(sgl, sg, sg_len, i) { desc->sg[i].addr = sg_dma_address(sg); desc->sg[i].len = sg_dma_len(sg); } desc->num_sgs = sg_len; desc->direction = direction; desc->cyclic = false; return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); } static struct dma_async_tx_descriptor *jz4740_dma_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 jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c); struct jz4740_dma_desc *desc; unsigned int num_periods, i; if (buf_len % period_len) return NULL; num_periods = buf_len / period_len; desc = jz4740_dma_alloc_desc(num_periods); if (!desc) return NULL; for (i = 0; i < num_periods; i++) { desc->sg[i].addr = buf_addr; desc->sg[i].len = period_len; buf_addr += period_len; } desc->num_sgs = num_periods; desc->direction = direction; desc->cyclic = true; return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); } static size_t jz4740_dma_desc_residue(struct jz4740_dmaengine_chan *chan, struct jz4740_dma_desc *desc, unsigned int next_sg) { struct jz4740_dma_dev *dmadev = jz4740_dma_chan_get_dev(chan); unsigned int residue, count; unsigned int i; residue = 0; for (i = next_sg; i < desc->num_sgs; i++) residue += desc->sg[i].len; if (next_sg != 0) { count = jz4740_dma_read(dmadev, JZ_REG_DMA_TRANSFER_COUNT(chan->id)); residue += count << chan->transfer_shift; } return residue; } static enum dma_status jz4740_dma_tx_status(struct dma_chan *c, dma_cookie_t cookie, struct dma_tx_state *state) { struct jz4740_dmaengine_chan *chan = to_jz4740_dma_chan(c); struct virt_dma_desc *vdesc; enum dma_status status; unsigned long flags; status = dma_cookie_status(c, cookie, state); if (status == DMA_COMPLETE || !state) return status; spin_lock_irqsave(&chan->vchan.lock, flags); vdesc = vchan_find_desc(&chan->vchan, cookie); if (cookie == chan->desc->vdesc.tx.cookie) { state->residue = jz4740_dma_desc_residue(chan, chan->desc, chan->next_sg); } else if (vdesc) { state->residue = jz4740_dma_desc_residue(chan, to_jz4740_dma_desc(vdesc), 0); } else { state->residue = 0; } spin_unlock_irqrestore(&chan->vchan.lock, flags); return status; } static void jz4740_dma_free_chan_resources(struct dma_chan *c) { vchan_free_chan_resources(to_virt_chan(c)); } static void jz4740_dma_desc_free(struct virt_dma_desc *vdesc) { kfree(container_of(vdesc, struct jz4740_dma_desc, vdesc)); } #define JZ4740_DMA_BUSWIDTHS (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \ BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)) static int jz4740_dma_probe(struct platform_device *pdev) { struct jz4740_dmaengine_chan *chan; struct jz4740_dma_dev *dmadev; struct dma_device *dd; unsigned int i; struct resource *res; int ret; int irq; dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL); if (!dmadev) return -EINVAL; dd = &dmadev->ddev; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); dmadev->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(dmadev->base)) return PTR_ERR(dmadev->base); dmadev->clk = clk_get(&pdev->dev, "dma"); if (IS_ERR(dmadev->clk)) return PTR_ERR(dmadev->clk); clk_prepare_enable(dmadev->clk); dma_cap_set(DMA_SLAVE, dd->cap_mask); dma_cap_set(DMA_CYCLIC, dd->cap_mask); dd->device_free_chan_resources = jz4740_dma_free_chan_resources; dd->device_tx_status = jz4740_dma_tx_status; dd->device_issue_pending = jz4740_dma_issue_pending; dd->device_prep_slave_sg = jz4740_dma_prep_slave_sg; dd->device_prep_dma_cyclic = jz4740_dma_prep_dma_cyclic; dd->device_config = jz4740_dma_slave_config; dd->device_terminate_all = jz4740_dma_terminate_all; dd->src_addr_widths = JZ4740_DMA_BUSWIDTHS; dd->dst_addr_widths = JZ4740_DMA_BUSWIDTHS; dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; dd->dev = &pdev->dev; INIT_LIST_HEAD(&dd->channels); for (i = 0; i < JZ_DMA_NR_CHANS; i++) { chan = &dmadev->chan[i]; chan->id = i; chan->vchan.desc_free = jz4740_dma_desc_free; vchan_init(&chan->vchan, dd); } ret = dma_async_device_register(dd); if (ret) goto err_clk; irq = platform_get_irq(pdev, 0); ret = request_irq(irq, jz4740_dma_irq, 0, dev_name(&pdev->dev), dmadev); if (ret) goto err_unregister; platform_set_drvdata(pdev, dmadev); return 0; err_unregister: dma_async_device_unregister(dd); err_clk: clk_disable_unprepare(dmadev->clk); return ret; } static void jz4740_cleanup_vchan(struct dma_device *dmadev) { struct jz4740_dmaengine_chan *chan, *_chan; list_for_each_entry_safe(chan, _chan, &dmadev->channels, vchan.chan.device_node) { list_del(&chan->vchan.chan.device_node); tasklet_kill(&chan->vchan.task); } } static int jz4740_dma_remove(struct platform_device *pdev) { struct jz4740_dma_dev *dmadev = platform_get_drvdata(pdev); int irq = platform_get_irq(pdev, 0); free_irq(irq, dmadev); jz4740_cleanup_vchan(&dmadev->ddev); dma_async_device_unregister(&dmadev->ddev); clk_disable_unprepare(dmadev->clk); return 0; } static struct platform_driver jz4740_dma_driver = { .probe = jz4740_dma_probe, .remove = jz4740_dma_remove, .driver = { .name = "jz4740-dma", }, }; module_platform_driver(jz4740_dma_driver); MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); MODULE_DESCRIPTION("JZ4740 DMA driver"); MODULE_LICENSE("GPL v2");