linux/drivers/dma/fsl-edma.c

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/*
* drivers/dma/fsl-edma.c
*
* Copyright 2013-2014 Freescale Semiconductor, Inc.
*
* Driver for the Freescale eDMA engine with flexible channel multiplexing
* capability for DMA request sources. The eDMA block can be found on some
* Vybrid and Layerscape SoCs.
*
* 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/module.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_dma.h>
#include "fsl-edma-common.h"
static irqreturn_t fsl_edma_tx_handler(int irq, void *dev_id)
{
struct fsl_edma_engine *fsl_edma = dev_id;
unsigned int intr, ch;
struct edma_regs *regs = &fsl_edma->regs;
struct fsl_edma_chan *fsl_chan;
intr = edma_readl(fsl_edma, regs->intl);
if (!intr)
return IRQ_NONE;
for (ch = 0; ch < fsl_edma->n_chans; ch++) {
if (intr & (0x1 << ch)) {
edma_writeb(fsl_edma, EDMA_CINT_CINT(ch), regs->cint);
fsl_chan = &fsl_edma->chans[ch];
spin_lock(&fsl_chan->vchan.lock);
if (!fsl_chan->edesc->iscyclic) {
list_del(&fsl_chan->edesc->vdesc.node);
vchan_cookie_complete(&fsl_chan->edesc->vdesc);
fsl_chan->edesc = NULL;
fsl_chan->status = DMA_COMPLETE;
fsl_chan->idle = true;
} else {
vchan_cyclic_callback(&fsl_chan->edesc->vdesc);
}
if (!fsl_chan->edesc)
fsl_edma_xfer_desc(fsl_chan);
spin_unlock(&fsl_chan->vchan.lock);
}
}
return IRQ_HANDLED;
}
static irqreturn_t fsl_edma_err_handler(int irq, void *dev_id)
{
struct fsl_edma_engine *fsl_edma = dev_id;
unsigned int err, ch;
struct edma_regs *regs = &fsl_edma->regs;
err = edma_readl(fsl_edma, regs->errl);
if (!err)
return IRQ_NONE;
for (ch = 0; ch < fsl_edma->n_chans; ch++) {
if (err & (0x1 << ch)) {
fsl_edma_disable_request(&fsl_edma->chans[ch]);
edma_writeb(fsl_edma, EDMA_CERR_CERR(ch), regs->cerr);
fsl_edma->chans[ch].status = DMA_ERROR;
fsl_edma->chans[ch].idle = true;
}
}
return IRQ_HANDLED;
}
static irqreturn_t fsl_edma_irq_handler(int irq, void *dev_id)
{
if (fsl_edma_tx_handler(irq, dev_id) == IRQ_HANDLED)
return IRQ_HANDLED;
return fsl_edma_err_handler(irq, dev_id);
}
static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct fsl_edma_engine *fsl_edma = ofdma->of_dma_data;
struct dma_chan *chan, *_chan;
struct fsl_edma_chan *fsl_chan;
unsigned long chans_per_mux = fsl_edma->n_chans / DMAMUX_NR;
if (dma_spec->args_count != 2)
return NULL;
mutex_lock(&fsl_edma->fsl_edma_mutex);
list_for_each_entry_safe(chan, _chan, &fsl_edma->dma_dev.channels, device_node) {
if (chan->client_count)
continue;
if ((chan->chan_id / chans_per_mux) == dma_spec->args[0]) {
chan = dma_get_slave_channel(chan);
if (chan) {
chan->device->privatecnt++;
fsl_chan = to_fsl_edma_chan(chan);
fsl_chan->slave_id = dma_spec->args[1];
fsl_edma_chan_mux(fsl_chan, fsl_chan->slave_id,
true);
mutex_unlock(&fsl_edma->fsl_edma_mutex);
return chan;
}
}
}
mutex_unlock(&fsl_edma->fsl_edma_mutex);
return NULL;
}
static int
fsl_edma_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
{
int ret;
fsl_edma->txirq = platform_get_irq_byname(pdev, "edma-tx");
if (fsl_edma->txirq < 0) {
dev_err(&pdev->dev, "Can't get edma-tx irq.\n");
return fsl_edma->txirq;
}
fsl_edma->errirq = platform_get_irq_byname(pdev, "edma-err");
if (fsl_edma->errirq < 0) {
dev_err(&pdev->dev, "Can't get edma-err irq.\n");
return fsl_edma->errirq;
}
if (fsl_edma->txirq == fsl_edma->errirq) {
ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
fsl_edma_irq_handler, 0, "eDMA", fsl_edma);
if (ret) {
dev_err(&pdev->dev, "Can't register eDMA IRQ.\n");
return ret;
}
} else {
ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
fsl_edma_tx_handler, 0, "eDMA tx", fsl_edma);
if (ret) {
dev_err(&pdev->dev, "Can't register eDMA tx IRQ.\n");
return ret;
}
ret = devm_request_irq(&pdev->dev, fsl_edma->errirq,
fsl_edma_err_handler, 0, "eDMA err", fsl_edma);
if (ret) {
dev_err(&pdev->dev, "Can't register eDMA err IRQ.\n");
return ret;
}
}
return 0;
}
static void fsl_edma_irq_exit(
struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
{
if (fsl_edma->txirq == fsl_edma->errirq) {
devm_free_irq(&pdev->dev, fsl_edma->txirq, fsl_edma);
} else {
devm_free_irq(&pdev->dev, fsl_edma->txirq, fsl_edma);
devm_free_irq(&pdev->dev, fsl_edma->errirq, fsl_edma);
}
}
static void fsl_disable_clocks(struct fsl_edma_engine *fsl_edma, int nr_clocks)
{
int i;
for (i = 0; i < nr_clocks; i++)
clk_disable_unprepare(fsl_edma->muxclk[i]);
}
static int fsl_edma_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct fsl_edma_engine *fsl_edma;
struct fsl_edma_chan *fsl_chan;
struct edma_regs *regs;
struct resource *res;
int len, chans;
int ret, i;
ret = of_property_read_u32(np, "dma-channels", &chans);
if (ret) {
dev_err(&pdev->dev, "Can't get dma-channels.\n");
return ret;
}
len = sizeof(*fsl_edma) + sizeof(*fsl_chan) * chans;
fsl_edma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
if (!fsl_edma)
return -ENOMEM;
fsl_edma->version = v1;
fsl_edma->n_chans = chans;
mutex_init(&fsl_edma->fsl_edma_mutex);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
fsl_edma->membase = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(fsl_edma->membase))
return PTR_ERR(fsl_edma->membase);
fsl_edma_setup_regs(fsl_edma);
regs = &fsl_edma->regs;
for (i = 0; i < DMAMUX_NR; i++) {
char clkname[32];
res = platform_get_resource(pdev, IORESOURCE_MEM, 1 + i);
fsl_edma->muxbase[i] = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(fsl_edma->muxbase[i])) {
/* on error: disable all previously enabled clks */
fsl_disable_clocks(fsl_edma, i);
return PTR_ERR(fsl_edma->muxbase[i]);
}
sprintf(clkname, "dmamux%d", i);
fsl_edma->muxclk[i] = devm_clk_get(&pdev->dev, clkname);
if (IS_ERR(fsl_edma->muxclk[i])) {
dev_err(&pdev->dev, "Missing DMAMUX block clock.\n");
/* on error: disable all previously enabled clks */
fsl_disable_clocks(fsl_edma, i);
return PTR_ERR(fsl_edma->muxclk[i]);
}
ret = clk_prepare_enable(fsl_edma->muxclk[i]);
if (ret)
/* on error: disable all previously enabled clks */
fsl_disable_clocks(fsl_edma, i);
}
fsl_edma->big_endian = of_property_read_bool(np, "big-endian");
INIT_LIST_HEAD(&fsl_edma->dma_dev.channels);
for (i = 0; i < fsl_edma->n_chans; i++) {
struct fsl_edma_chan *fsl_chan = &fsl_edma->chans[i];
fsl_chan->edma = fsl_edma;
fsl_chan->pm_state = RUNNING;
fsl_chan->slave_id = 0;
fsl_chan->idle = true;
fsl_chan->vchan.desc_free = fsl_edma_free_desc;
vchan_init(&fsl_chan->vchan, &fsl_edma->dma_dev);
edma_writew(fsl_edma, 0x0, &regs->tcd[i].csr);
fsl_edma_chan_mux(fsl_chan, 0, false);
}
edma_writel(fsl_edma, ~0, regs->intl);
ret = fsl_edma_irq_init(pdev, fsl_edma);
if (ret)
return ret;
dma_cap_set(DMA_PRIVATE, fsl_edma->dma_dev.cap_mask);
dma_cap_set(DMA_SLAVE, fsl_edma->dma_dev.cap_mask);
dma_cap_set(DMA_CYCLIC, fsl_edma->dma_dev.cap_mask);
fsl_edma->dma_dev.dev = &pdev->dev;
fsl_edma->dma_dev.device_alloc_chan_resources
= fsl_edma_alloc_chan_resources;
fsl_edma->dma_dev.device_free_chan_resources
= fsl_edma_free_chan_resources;
fsl_edma->dma_dev.device_tx_status = fsl_edma_tx_status;
fsl_edma->dma_dev.device_prep_slave_sg = fsl_edma_prep_slave_sg;
fsl_edma->dma_dev.device_prep_dma_cyclic = fsl_edma_prep_dma_cyclic;
fsl_edma->dma_dev.device_config = fsl_edma_slave_config;
fsl_edma->dma_dev.device_pause = fsl_edma_pause;
fsl_edma->dma_dev.device_resume = fsl_edma_resume;
fsl_edma->dma_dev.device_terminate_all = fsl_edma_terminate_all;
fsl_edma->dma_dev.device_issue_pending = fsl_edma_issue_pending;
fsl_edma->dma_dev.src_addr_widths = FSL_EDMA_BUSWIDTHS;
fsl_edma->dma_dev.dst_addr_widths = FSL_EDMA_BUSWIDTHS;
fsl_edma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
platform_set_drvdata(pdev, fsl_edma);
ret = dma_async_device_register(&fsl_edma->dma_dev);
if (ret) {
dev_err(&pdev->dev,
"Can't register Freescale eDMA engine. (%d)\n", ret);
fsl_disable_clocks(fsl_edma, DMAMUX_NR);
return ret;
}
ret = of_dma_controller_register(np, fsl_edma_xlate, fsl_edma);
if (ret) {
dev_err(&pdev->dev,
"Can't register Freescale eDMA of_dma. (%d)\n", ret);
dma_async_device_unregister(&fsl_edma->dma_dev);
fsl_disable_clocks(fsl_edma, DMAMUX_NR);
return ret;
}
/* enable round robin arbitration */
edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA, regs->cr);
return 0;
}
static int fsl_edma_remove(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct fsl_edma_engine *fsl_edma = platform_get_drvdata(pdev);
fsl_edma_irq_exit(pdev, fsl_edma);
fsl_edma_cleanup_vchan(&fsl_edma->dma_dev);
of_dma_controller_free(np);
dma_async_device_unregister(&fsl_edma->dma_dev);
fsl_disable_clocks(fsl_edma, DMAMUX_NR);
return 0;
}
static int fsl_edma_suspend_late(struct device *dev)
{
struct fsl_edma_engine *fsl_edma = dev_get_drvdata(dev);
struct fsl_edma_chan *fsl_chan;
unsigned long flags;
int i;
for (i = 0; i < fsl_edma->n_chans; i++) {
fsl_chan = &fsl_edma->chans[i];
spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
/* Make sure chan is idle or will force disable. */
if (unlikely(!fsl_chan->idle)) {
dev_warn(dev, "WARN: There is non-idle channel.");
fsl_edma_disable_request(fsl_chan);
fsl_edma_chan_mux(fsl_chan, 0, false);
}
fsl_chan->pm_state = SUSPENDED;
spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
}
return 0;
}
static int fsl_edma_resume_early(struct device *dev)
{
struct fsl_edma_engine *fsl_edma = dev_get_drvdata(dev);
struct fsl_edma_chan *fsl_chan;
struct edma_regs *regs = &fsl_edma->regs;
int i;
for (i = 0; i < fsl_edma->n_chans; i++) {
fsl_chan = &fsl_edma->chans[i];
fsl_chan->pm_state = RUNNING;
edma_writew(fsl_edma, 0x0, &regs->tcd[i].csr);
if (fsl_chan->slave_id != 0)
fsl_edma_chan_mux(fsl_chan, fsl_chan->slave_id, true);
}
edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA, regs->cr);
return 0;
}
/*
* eDMA provides the service to others, so it should be suspend late
* and resume early. When eDMA suspend, all of the clients should stop
* the DMA data transmission and let the channel idle.
*/
static const struct dev_pm_ops fsl_edma_pm_ops = {
.suspend_late = fsl_edma_suspend_late,
.resume_early = fsl_edma_resume_early,
};
static const struct of_device_id fsl_edma_dt_ids[] = {
{ .compatible = "fsl,vf610-edma", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, fsl_edma_dt_ids);
static struct platform_driver fsl_edma_driver = {
.driver = {
.name = "fsl-edma",
.of_match_table = fsl_edma_dt_ids,
.pm = &fsl_edma_pm_ops,
},
.probe = fsl_edma_probe,
.remove = fsl_edma_remove,
};
static int __init fsl_edma_init(void)
{
return platform_driver_register(&fsl_edma_driver);
}
subsys_initcall(fsl_edma_init);
static void __exit fsl_edma_exit(void)
{
platform_driver_unregister(&fsl_edma_driver);
}
module_exit(fsl_edma_exit);
MODULE_ALIAS("platform:fsl-edma");
MODULE_DESCRIPTION("Freescale eDMA engine driver");
MODULE_LICENSE("GPL v2");