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|
// 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;
unsigned long flags;
spin_lock_irqsave(&chan->lock, flags);
if (chan->desc && !chan->desc->in_use) {
spin_unlock_irqrestore(&chan->lock, flags);
return chan->desc;
}
spin_unlock_irqrestore(&chan->lock, flags);
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;
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, flags);
chan->desc = desc;
sf_pdma_fill_desc(desc, dest, src, len);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
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;
spin_lock_irqsave(&chan->vchan.lock, flags);
tx = &chan->desc->vdesc.tx;
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 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 (vchan_issue_pending(&chan->vchan) && chan->desc)
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);
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>");
|