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dmaengine: fsl-edma: add PM suspend/resume support

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This add power management suspend/resume support for the fsl-edma
driver.

eDMA acted as a basic function used by others. What it needs to do
is the two steps below to support power management.

In fsl_edma_suspend_late:
Check whether the DMA chan is idle, if it is not idle disable DMA
request.

In fsl_edma_resume_early:
Enable the eDMA and wait for being used.

Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Yuan Yao 2015-10-30 19:03:58 +08:00 committed by Vinod Koul
parent f0579c8cea
commit 82d149b86d
1 changed files with 82 additions and 3 deletions
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85
drivers/dma/fsl-edma.c
View file

@ -116,6 +116,10 @@
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES)
enum fsl_edma_pm_state {
RUNNING = 0,
SUSPENDED,
};
struct fsl_edma_hw_tcd {
__le32 saddr;
@ -147,6 +151,9 @@ struct fsl_edma_slave_config {
struct fsl_edma_chan {
struct virt_dma_chan vchan;
enum dma_status status;
enum fsl_edma_pm_state pm_state;
bool idle;
u32 slave_id;
struct fsl_edma_engine *edma;
struct fsl_edma_desc *edesc;
struct fsl_edma_slave_config fsc;
@ -298,6 +305,7 @@ static int fsl_edma_terminate_all(struct dma_chan *chan)
spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
fsl_edma_disable_request(fsl_chan);
fsl_chan->edesc = NULL;
fsl_chan->idle = true;
vchan_get_all_descriptors(&fsl_chan->vchan, &head);
spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
@ -313,6 +321,7 @@ static int fsl_edma_pause(struct dma_chan *chan)
if (fsl_chan->edesc) {
fsl_edma_disable_request(fsl_chan);
fsl_chan->status = DMA_PAUSED;
fsl_chan->idle = true;
}
spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
return 0;
@ -327,6 +336,7 @@ static int fsl_edma_resume(struct dma_chan *chan)
if (fsl_chan->edesc) {
fsl_edma_enable_request(fsl_chan);
fsl_chan->status = DMA_IN_PROGRESS;
fsl_chan->idle = false;
}
spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
return 0;
@ -648,6 +658,7 @@ static void fsl_edma_xfer_desc(struct fsl_edma_chan *fsl_chan)
fsl_edma_set_tcd_regs(fsl_chan, fsl_chan->edesc->tcd[0].vtcd);
fsl_edma_enable_request(fsl_chan);
fsl_chan->status = DMA_IN_PROGRESS;
fsl_chan->idle = false;
}
static irqreturn_t fsl_edma_tx_handler(int irq, void *dev_id)
@ -676,6 +687,7 @@ static irqreturn_t fsl_edma_tx_handler(int irq, void *dev_id)
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);
}
@ -704,6 +716,7 @@ static irqreturn_t fsl_edma_err_handler(int irq, void *dev_id)
edma_writeb(fsl_edma, EDMA_CERR_CERR(ch),
fsl_edma->membase + EDMA_CERR);
fsl_edma->chans[ch].status = DMA_ERROR;
fsl_edma->chans[ch].idle = true;
}
}
return IRQ_HANDLED;
@ -724,6 +737,12 @@ static void fsl_edma_issue_pending(struct dma_chan *chan)
spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
if (unlikely(fsl_chan->pm_state != RUNNING)) {
spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
/* cannot submit due to suspend */
return;
}
if (vchan_issue_pending(&fsl_chan->vchan) && !fsl_chan->edesc)
fsl_edma_xfer_desc(fsl_chan);
@ -735,6 +754,7 @@ static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
{
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)
@ -748,8 +768,10 @@ static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
chan = dma_get_slave_channel(chan);
if (chan) {
chan->device->privatecnt++;
fsl_edma_chan_mux(to_fsl_edma_chan(chan),
dma_spec->args[1], true);
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;
}
@ -888,7 +910,9 @@ static int fsl_edma_probe(struct platform_device *pdev)
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);
@ -959,6 +983,60 @@ static int fsl_edma_remove(struct platform_device *pdev)
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;
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, fsl_edma->membase + EDMA_TCD_CSR(i));
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,
fsl_edma->membase + EDMA_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 */ }
@ -969,6 +1047,7 @@ 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,