diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/dma/sf-pdma/sf-pdma.c | 624 |
1 files changed, 624 insertions, 0 deletions
diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c new file mode 100644 index 000000000..5c615a8b5 --- /dev/null +++ b/drivers/dma/sf-pdma/sf-pdma.c @@ -0,0 +1,624 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * SiFive FU540 Platform DMA driver + * Copyright (C) 2019 SiFive + * + * Based partially on: + * - drivers/dma/fsl-edma.c + * - drivers/dma/dw-edma/ + * - drivers/dma/pxa-dma.c + * + * See the following sources for further documentation: + * - Chapter 12 "Platform DMA Engine (PDMA)" of + * SiFive FU540-C000 v1.0 + * https://static.dev.sifive.com/FU540-C000-v1.0.pdf + */ +#include <linux/module.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/mod_devicetable.h> +#include <linux/dma-mapping.h> +#include <linux/of.h> +#include <linux/slab.h> + +#include "sf-pdma.h" + +#ifndef readq +static inline unsigned long long readq(void __iomem *addr) +{ + return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL); +} +#endif + +#ifndef writeq +static inline void writeq(unsigned long long v, void __iomem *addr) +{ + writel(lower_32_bits(v), addr); + writel(upper_32_bits(v), addr + 4); +} +#endif + +static inline struct sf_pdma_chan *to_sf_pdma_chan(struct dma_chan *dchan) +{ + return container_of(dchan, struct sf_pdma_chan, vchan.chan); +} + +static inline struct sf_pdma_desc *to_sf_pdma_desc(struct virt_dma_desc *vd) +{ + return container_of(vd, struct sf_pdma_desc, vdesc); +} + +static struct sf_pdma_desc *sf_pdma_alloc_desc(struct sf_pdma_chan *chan) +{ + struct sf_pdma_desc *desc; + + desc = kzalloc(sizeof(*desc), GFP_NOWAIT); + if (!desc) + return NULL; + + desc->chan = chan; + + return desc; +} + +static void sf_pdma_fill_desc(struct sf_pdma_desc *desc, + u64 dst, u64 src, u64 size) +{ + desc->xfer_type = PDMA_FULL_SPEED; + desc->xfer_size = size; + desc->dst_addr = dst; + desc->src_addr = src; +} + +static void sf_pdma_disclaim_chan(struct sf_pdma_chan *chan) +{ + struct pdma_regs *regs = &chan->regs; + + writel(PDMA_CLEAR_CTRL, regs->ctrl); +} + +static struct dma_async_tx_descriptor * +sf_pdma_prep_dma_memcpy(struct dma_chan *dchan, dma_addr_t dest, dma_addr_t src, + size_t len, unsigned long flags) +{ + struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan); + struct sf_pdma_desc *desc; + unsigned long iflags; + + if (chan && (!len || !dest || !src)) { + dev_err(chan->pdma->dma_dev.dev, + "Please check dma len, dest, src!\n"); + return NULL; + } + + desc = sf_pdma_alloc_desc(chan); + if (!desc) + return NULL; + + desc->in_use = true; + desc->dirn = DMA_MEM_TO_MEM; + desc->async_tx = vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); + + spin_lock_irqsave(&chan->vchan.lock, iflags); + sf_pdma_fill_desc(desc, dest, src, len); + spin_unlock_irqrestore(&chan->vchan.lock, iflags); + + return desc->async_tx; +} + +static int sf_pdma_slave_config(struct dma_chan *dchan, + struct dma_slave_config *cfg) +{ + struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan); + + memcpy(&chan->cfg, cfg, sizeof(*cfg)); + + return 0; +} + +static int sf_pdma_alloc_chan_resources(struct dma_chan *dchan) +{ + struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan); + struct pdma_regs *regs = &chan->regs; + + dma_cookie_init(dchan); + writel(PDMA_CLAIM_MASK, regs->ctrl); + + return 0; +} + +static void sf_pdma_disable_request(struct sf_pdma_chan *chan) +{ + struct pdma_regs *regs = &chan->regs; + + writel(readl(regs->ctrl) & ~PDMA_RUN_MASK, regs->ctrl); +} + +static void sf_pdma_free_chan_resources(struct dma_chan *dchan) +{ + struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan); + unsigned long flags; + LIST_HEAD(head); + + spin_lock_irqsave(&chan->vchan.lock, flags); + sf_pdma_disable_request(chan); + kfree(chan->desc); + chan->desc = NULL; + vchan_get_all_descriptors(&chan->vchan, &head); + sf_pdma_disclaim_chan(chan); + spin_unlock_irqrestore(&chan->vchan.lock, flags); + vchan_dma_desc_free_list(&chan->vchan, &head); +} + +static size_t sf_pdma_desc_residue(struct sf_pdma_chan *chan, + dma_cookie_t cookie) +{ + struct virt_dma_desc *vd = NULL; + struct pdma_regs *regs = &chan->regs; + unsigned long flags; + u64 residue = 0; + struct sf_pdma_desc *desc; + struct dma_async_tx_descriptor *tx = NULL; + + spin_lock_irqsave(&chan->vchan.lock, flags); + + list_for_each_entry(vd, &chan->vchan.desc_submitted, node) + if (vd->tx.cookie == cookie) + tx = &vd->tx; + + if (!tx) + goto out; + + if (cookie == tx->chan->completed_cookie) + goto out; + + if (cookie == tx->cookie) { + residue = readq(regs->residue); + } else { + vd = vchan_find_desc(&chan->vchan, cookie); + if (!vd) + goto out; + + desc = to_sf_pdma_desc(vd); + residue = desc->xfer_size; + } + +out: + spin_unlock_irqrestore(&chan->vchan.lock, flags); + return residue; +} + +static enum dma_status +sf_pdma_tx_status(struct dma_chan *dchan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan); + enum dma_status status; + + status = dma_cookie_status(dchan, cookie, txstate); + + if (txstate && status != DMA_ERROR) + dma_set_residue(txstate, sf_pdma_desc_residue(chan, cookie)); + + return status; +} + +static int sf_pdma_terminate_all(struct dma_chan *dchan) +{ + struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan); + unsigned long flags; + LIST_HEAD(head); + + spin_lock_irqsave(&chan->vchan.lock, flags); + sf_pdma_disable_request(chan); + kfree(chan->desc); + chan->desc = NULL; + chan->xfer_err = false; + 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 void sf_pdma_enable_request(struct sf_pdma_chan *chan) +{ + struct pdma_regs *regs = &chan->regs; + u32 v; + + v = PDMA_CLAIM_MASK | + PDMA_ENABLE_DONE_INT_MASK | + PDMA_ENABLE_ERR_INT_MASK | + PDMA_RUN_MASK; + + writel(v, regs->ctrl); +} + +static struct sf_pdma_desc *sf_pdma_get_first_pending_desc(struct sf_pdma_chan *chan) +{ + struct virt_dma_chan *vchan = &chan->vchan; + struct virt_dma_desc *vdesc; + + if (list_empty(&vchan->desc_issued)) + return NULL; + + vdesc = list_first_entry(&vchan->desc_issued, struct virt_dma_desc, node); + + return container_of(vdesc, struct sf_pdma_desc, vdesc); +} + +static void sf_pdma_xfer_desc(struct sf_pdma_chan *chan) +{ + struct sf_pdma_desc *desc = chan->desc; + struct pdma_regs *regs = &chan->regs; + + if (!desc) { + dev_err(chan->pdma->dma_dev.dev, "NULL desc.\n"); + return; + } + + writel(desc->xfer_type, regs->xfer_type); + writeq(desc->xfer_size, regs->xfer_size); + writeq(desc->dst_addr, regs->dst_addr); + writeq(desc->src_addr, regs->src_addr); + + chan->desc = desc; + chan->status = DMA_IN_PROGRESS; + sf_pdma_enable_request(chan); +} + +static void sf_pdma_issue_pending(struct dma_chan *dchan) +{ + struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan); + unsigned long flags; + + spin_lock_irqsave(&chan->vchan.lock, flags); + + if (!chan->desc && vchan_issue_pending(&chan->vchan)) { + /* vchan_issue_pending has made a check that desc in not NULL */ + chan->desc = sf_pdma_get_first_pending_desc(chan); + sf_pdma_xfer_desc(chan); + } + + spin_unlock_irqrestore(&chan->vchan.lock, flags); +} + +static void sf_pdma_free_desc(struct virt_dma_desc *vdesc) +{ + struct sf_pdma_desc *desc; + + desc = to_sf_pdma_desc(vdesc); + desc->in_use = false; +} + +static void sf_pdma_donebh_tasklet(struct tasklet_struct *t) +{ + struct sf_pdma_chan *chan = from_tasklet(chan, t, done_tasklet); + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + if (chan->xfer_err) { + chan->retries = MAX_RETRY; + chan->status = DMA_COMPLETE; + chan->xfer_err = false; + } + spin_unlock_irqrestore(&chan->lock, flags); + + spin_lock_irqsave(&chan->vchan.lock, flags); + list_del(&chan->desc->vdesc.node); + vchan_cookie_complete(&chan->desc->vdesc); + + chan->desc = sf_pdma_get_first_pending_desc(chan); + if (chan->desc) + sf_pdma_xfer_desc(chan); + + spin_unlock_irqrestore(&chan->vchan.lock, flags); +} + +static void sf_pdma_errbh_tasklet(struct tasklet_struct *t) +{ + struct sf_pdma_chan *chan = from_tasklet(chan, t, err_tasklet); + struct sf_pdma_desc *desc = chan->desc; + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + if (chan->retries <= 0) { + /* fail to recover */ + spin_unlock_irqrestore(&chan->lock, flags); + dmaengine_desc_get_callback_invoke(desc->async_tx, NULL); + } else { + /* retry */ + chan->retries--; + chan->xfer_err = true; + chan->status = DMA_ERROR; + + sf_pdma_enable_request(chan); + spin_unlock_irqrestore(&chan->lock, flags); + } +} + +static irqreturn_t sf_pdma_done_isr(int irq, void *dev_id) +{ + struct sf_pdma_chan *chan = dev_id; + struct pdma_regs *regs = &chan->regs; + unsigned long flags; + u64 residue; + + spin_lock_irqsave(&chan->vchan.lock, flags); + writel((readl(regs->ctrl)) & ~PDMA_DONE_STATUS_MASK, regs->ctrl); + residue = readq(regs->residue); + + if (!residue) { + tasklet_hi_schedule(&chan->done_tasklet); + } else { + /* submit next trascatioin if possible */ + struct sf_pdma_desc *desc = chan->desc; + + desc->src_addr += desc->xfer_size - residue; + desc->dst_addr += desc->xfer_size - residue; + desc->xfer_size = residue; + + sf_pdma_xfer_desc(chan); + } + + spin_unlock_irqrestore(&chan->vchan.lock, flags); + + return IRQ_HANDLED; +} + +static irqreturn_t sf_pdma_err_isr(int irq, void *dev_id) +{ + struct sf_pdma_chan *chan = dev_id; + struct pdma_regs *regs = &chan->regs; + unsigned long flags; + + spin_lock_irqsave(&chan->lock, flags); + writel((readl(regs->ctrl)) & ~PDMA_ERR_STATUS_MASK, regs->ctrl); + spin_unlock_irqrestore(&chan->lock, flags); + + tasklet_schedule(&chan->err_tasklet); + + return IRQ_HANDLED; +} + +/** + * sf_pdma_irq_init() - Init PDMA IRQ Handlers + * @pdev: pointer of platform_device + * @pdma: pointer of PDMA engine. Caller should check NULL + * + * Initialize DONE and ERROR interrupt handler for 4 channels. Caller should + * make sure the pointer passed in are non-NULL. This function should be called + * only one time during the device probe. + * + * Context: Any context. + * + * Return: + * * 0 - OK to init all IRQ handlers + * * -EINVAL - Fail to request IRQ + */ +static int sf_pdma_irq_init(struct platform_device *pdev, struct sf_pdma *pdma) +{ + int irq, r, i; + struct sf_pdma_chan *chan; + + for (i = 0; i < pdma->n_chans; i++) { + chan = &pdma->chans[i]; + + irq = platform_get_irq(pdev, i * 2); + if (irq < 0) { + dev_err(&pdev->dev, "ch(%d) Can't get done irq.\n", i); + return -EINVAL; + } + + r = devm_request_irq(&pdev->dev, irq, sf_pdma_done_isr, 0, + dev_name(&pdev->dev), (void *)chan); + if (r) { + dev_err(&pdev->dev, "Fail to attach done ISR: %d\n", r); + return -EINVAL; + } + + chan->txirq = irq; + + irq = platform_get_irq(pdev, (i * 2) + 1); + if (irq < 0) { + dev_err(&pdev->dev, "ch(%d) Can't get err irq.\n", i); + return -EINVAL; + } + + r = devm_request_irq(&pdev->dev, irq, sf_pdma_err_isr, 0, + dev_name(&pdev->dev), (void *)chan); + if (r) { + dev_err(&pdev->dev, "Fail to attach err ISR: %d\n", r); + return -EINVAL; + } + + chan->errirq = irq; + } + + return 0; +} + +/** + * sf_pdma_setup_chans() - Init settings of each channel + * @pdma: pointer of PDMA engine. Caller should check NULL + * + * Initialize all data structure and register base. Caller should make sure + * the pointer passed in are non-NULL. This function should be called only + * one time during the device probe. + * + * Context: Any context. + * + * Return: none + */ +static void sf_pdma_setup_chans(struct sf_pdma *pdma) +{ + int i; + struct sf_pdma_chan *chan; + + INIT_LIST_HEAD(&pdma->dma_dev.channels); + + for (i = 0; i < pdma->n_chans; i++) { + chan = &pdma->chans[i]; + + chan->regs.ctrl = + SF_PDMA_REG_BASE(i) + PDMA_CTRL; + chan->regs.xfer_type = + SF_PDMA_REG_BASE(i) + PDMA_XFER_TYPE; + chan->regs.xfer_size = + SF_PDMA_REG_BASE(i) + PDMA_XFER_SIZE; + chan->regs.dst_addr = + SF_PDMA_REG_BASE(i) + PDMA_DST_ADDR; + chan->regs.src_addr = + SF_PDMA_REG_BASE(i) + PDMA_SRC_ADDR; + chan->regs.act_type = + SF_PDMA_REG_BASE(i) + PDMA_ACT_TYPE; + chan->regs.residue = + SF_PDMA_REG_BASE(i) + PDMA_REMAINING_BYTE; + chan->regs.cur_dst_addr = + SF_PDMA_REG_BASE(i) + PDMA_CUR_DST_ADDR; + chan->regs.cur_src_addr = + SF_PDMA_REG_BASE(i) + PDMA_CUR_SRC_ADDR; + + chan->pdma = pdma; + chan->pm_state = RUNNING; + chan->slave_id = i; + chan->xfer_err = false; + spin_lock_init(&chan->lock); + + chan->vchan.desc_free = sf_pdma_free_desc; + vchan_init(&chan->vchan, &pdma->dma_dev); + + writel(PDMA_CLEAR_CTRL, chan->regs.ctrl); + + tasklet_setup(&chan->done_tasklet, sf_pdma_donebh_tasklet); + tasklet_setup(&chan->err_tasklet, sf_pdma_errbh_tasklet); + } +} + +static int sf_pdma_probe(struct platform_device *pdev) +{ + struct sf_pdma *pdma; + struct sf_pdma_chan *chan; + struct resource *res; + int len, chans; + int ret; + const enum dma_slave_buswidth widths = + DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES | + DMA_SLAVE_BUSWIDTH_4_BYTES | DMA_SLAVE_BUSWIDTH_8_BYTES | + DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES | + DMA_SLAVE_BUSWIDTH_64_BYTES; + + chans = PDMA_NR_CH; + len = sizeof(*pdma) + sizeof(*chan) * chans; + pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL); + if (!pdma) + return -ENOMEM; + + pdma->n_chans = chans; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + pdma->membase = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(pdma->membase)) + return PTR_ERR(pdma->membase); + + ret = sf_pdma_irq_init(pdev, pdma); + if (ret) + return ret; + + sf_pdma_setup_chans(pdma); + + pdma->dma_dev.dev = &pdev->dev; + + /* Setup capability */ + dma_cap_set(DMA_MEMCPY, pdma->dma_dev.cap_mask); + pdma->dma_dev.copy_align = 2; + pdma->dma_dev.src_addr_widths = widths; + pdma->dma_dev.dst_addr_widths = widths; + pdma->dma_dev.directions = BIT(DMA_MEM_TO_MEM); + pdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; + pdma->dma_dev.descriptor_reuse = true; + + /* Setup DMA APIs */ + pdma->dma_dev.device_alloc_chan_resources = + sf_pdma_alloc_chan_resources; + pdma->dma_dev.device_free_chan_resources = + sf_pdma_free_chan_resources; + pdma->dma_dev.device_tx_status = sf_pdma_tx_status; + pdma->dma_dev.device_prep_dma_memcpy = sf_pdma_prep_dma_memcpy; + pdma->dma_dev.device_config = sf_pdma_slave_config; + pdma->dma_dev.device_terminate_all = sf_pdma_terminate_all; + pdma->dma_dev.device_issue_pending = sf_pdma_issue_pending; + + platform_set_drvdata(pdev, pdma); + + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); + if (ret) + dev_warn(&pdev->dev, + "Failed to set DMA mask. Fall back to default.\n"); + + ret = dma_async_device_register(&pdma->dma_dev); + if (ret) { + dev_err(&pdev->dev, + "Can't register SiFive Platform DMA. (%d)\n", ret); + return ret; + } + + return 0; +} + +static int sf_pdma_remove(struct platform_device *pdev) +{ + struct sf_pdma *pdma = platform_get_drvdata(pdev); + struct sf_pdma_chan *ch; + int i; + + for (i = 0; i < PDMA_NR_CH; i++) { + ch = &pdma->chans[i]; + + devm_free_irq(&pdev->dev, ch->txirq, ch); + devm_free_irq(&pdev->dev, ch->errirq, ch); + list_del(&ch->vchan.chan.device_node); + tasklet_kill(&ch->vchan.task); + tasklet_kill(&ch->done_tasklet); + tasklet_kill(&ch->err_tasklet); + } + + dma_async_device_unregister(&pdma->dma_dev); + + return 0; +} + +static const struct of_device_id sf_pdma_dt_ids[] = { + { .compatible = "sifive,fu540-c000-pdma" }, + {}, +}; +MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids); + +static struct platform_driver sf_pdma_driver = { + .probe = sf_pdma_probe, + .remove = sf_pdma_remove, + .driver = { + .name = "sf-pdma", + .of_match_table = of_match_ptr(sf_pdma_dt_ids), + }, +}; + +static int __init sf_pdma_init(void) +{ + return platform_driver_register(&sf_pdma_driver); +} + +static void __exit sf_pdma_exit(void) +{ + platform_driver_unregister(&sf_pdma_driver); +} + +/* do early init */ +subsys_initcall(sf_pdma_init); +module_exit(sf_pdma_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("SiFive Platform DMA driver"); +MODULE_AUTHOR("Green Wan <green.wan@sifive.com>"); |