Re: [PATCH v2] mmc: atmel-mci: add runtime pm support

From: Ludovic Desroches
Date: Tue Nov 04 2014 - 08:15:01 EST

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On Tue, Nov 04, 2014 at 11:05:56AM +0100, Ulf Hansson wrote:
> On 30 October 2014 05:00, Wenyou Yang <wenyou.yang@xxxxxxxxx> wrote:
> > Add runtime pm support to atmel mci controller.
> > Use runtime pm APIs to enable/disable atmel mci's clock.
> > Use runtime autosuspend APIs to enable auto suspend delay.
> >
> > Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
>
Acked-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>

> Ludovic, any objections to this one?

I am not a PM runtime guru, since you have reviewed the first version,
it is ok for me :)

Regards

Ludovic

>
> Kind regards
> Uffe
>
> > ---
> > Changes v1 -> v2:
> > * Adjust the APIs and invoking sequence to avoid clock unbalance issue during ->probe.
> > * Fix miss to invoke clk_disable_unprepare() in the error handling in ->probe.
> > * Remove atmci_suspend/resume and use pm_runtime_force_suspend/resume() to simplify code.
> >
> > drivers/mmc/host/atmel-mci.c | 90 +++++++++++++++++++++++++++++++-----------
> > 1 file changed, 67 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
> > index 0b9ddf8..f8f2bbe 100644
> > --- a/drivers/mmc/host/atmel-mci.c
> > +++ b/drivers/mmc/host/atmel-mci.c
> > @@ -37,6 +37,8 @@
> >
> > #include <linux/atmel-mci.h>
> > #include <linux/atmel_pdc.h>
> > +#include <linux/pm.h>
> > +#include <linux/pm_runtime.h>
> >
> > #include <asm/cacheflush.h>
> > #include <asm/io.h>
> > @@ -44,6 +46,8 @@
> >
> > #include "atmel-mci-regs.h"
> >
> > +#define AUTOSUSPEND_DELAY 50
> > +
> > #define ATMCI_DATA_ERROR_FLAGS (ATMCI_DCRCE | ATMCI_DTOE | ATMCI_OVRE | ATMCI_UNRE)
> > #define ATMCI_DMA_THRESHOLD 16
> >
> > @@ -386,20 +390,19 @@ static int atmci_regs_show(struct seq_file *s, void *v)
> > if (!buf)
> > return -ENOMEM;
> >
> > + pm_runtime_get_sync(&host->pdev->dev);
> > +
> > /*
> > * Grab a more or less consistent snapshot. Note that we're
> > * not disabling interrupts, so IMR and SR may not be
> > * consistent.
> > */
> > - ret = clk_prepare_enable(host->mck);
> > - if (ret)
> > - goto out;
> > -
> > spin_lock_bh(&host->lock);
> > memcpy_fromio(buf, host->regs, ATMCI_REGS_SIZE);
> > spin_unlock_bh(&host->lock);
> >
> > - clk_disable_unprepare(host->mck);
> > + pm_runtime_mark_last_busy(&host->pdev->dev);
> > + pm_runtime_put_autosuspend(&host->pdev->dev);
> >
> > seq_printf(s, "MR:\t0x%08x%s%s ",
> > buf[ATMCI_MR / 4],
> > @@ -449,7 +452,6 @@ static int atmci_regs_show(struct seq_file *s, void *v)
> > val & ATMCI_CFG_LSYNC ? " LSYNC" : "");
> > }
> >
> > -out:
> > kfree(buf);
> >
> > return ret;
> > @@ -1252,6 +1254,8 @@ static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
> > WARN_ON(slot->mrq);
> > dev_dbg(&host->pdev->dev, "MRQ: cmd %u\n", mrq->cmd->opcode);
> >
> > + pm_runtime_get_sync(&host->pdev->dev);
> > +
> > /*
> > * We may "know" the card is gone even though there's still an
> > * electrical connection. If so, we really need to communicate
> > @@ -1281,7 +1285,8 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > struct atmel_mci_slot *slot = mmc_priv(mmc);
> > struct atmel_mci *host = slot->host;
> > unsigned int i;
> > - bool unprepare_clk;
> > +
> > + pm_runtime_get_sync(&host->pdev->dev);
> >
> > slot->sdc_reg &= ~ATMCI_SDCBUS_MASK;
> > switch (ios->bus_width) {
> > @@ -1297,13 +1302,8 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > unsigned int clock_min = ~0U;
> > u32 clkdiv;
> >
> > - clk_prepare(host->mck);
> > - unprepare_clk = true;
> > -
> > spin_lock_bh(&host->lock);
> > if (!host->mode_reg) {
> > - clk_enable(host->mck);
> > - unprepare_clk = false;
> > atmci_writel(host, ATMCI_CR, ATMCI_CR_SWRST);
> > atmci_writel(host, ATMCI_CR, ATMCI_CR_MCIEN);
> > if (host->caps.has_cfg_reg)
> > @@ -1371,8 +1371,6 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > } else {
> > bool any_slot_active = false;
> >
> > - unprepare_clk = false;
> > -
> > spin_lock_bh(&host->lock);
> > slot->clock = 0;
> > for (i = 0; i < ATMCI_MAX_NR_SLOTS; i++) {
> > @@ -1385,17 +1383,12 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > atmci_writel(host, ATMCI_CR, ATMCI_CR_MCIDIS);
> > if (host->mode_reg) {
> > atmci_readl(host, ATMCI_MR);
> > - clk_disable(host->mck);
> > - unprepare_clk = true;
> > }
> > host->mode_reg = 0;
> > }
> > spin_unlock_bh(&host->lock);
> > }
> >
> > - if (unprepare_clk)
> > - clk_unprepare(host->mck);
> > -
> > switch (ios->power_mode) {
> > case MMC_POWER_OFF:
> > if (!IS_ERR(mmc->supply.vmmc))
> > @@ -1421,6 +1414,9 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > */
> > break;
> > }
> > +
> > + pm_runtime_mark_last_busy(&host->pdev->dev);
> > + pm_runtime_put_autosuspend(&host->pdev->dev);
> > }
> >
> > static int atmci_get_ro(struct mmc_host *mmc)
> > @@ -1512,6 +1508,9 @@ static void atmci_request_end(struct atmel_mci *host, struct mmc_request *mrq)
> > spin_unlock(&host->lock);
> > mmc_request_done(prev_mmc, mrq);
> > spin_lock(&host->lock);
> > +
> > + pm_runtime_mark_last_busy(&host->pdev->dev);
> > + pm_runtime_put_autosuspend(&host->pdev->dev);
> > }
> >
> > static void atmci_command_complete(struct atmel_mci *host,
> > @@ -2417,15 +2416,16 @@ static int __init atmci_probe(struct platform_device *pdev)
> >
> > atmci_writel(host, ATMCI_CR, ATMCI_CR_SWRST);
> > host->bus_hz = clk_get_rate(host->mck);
> > - clk_disable_unprepare(host->mck);
> >
> > host->mapbase = regs->start;
> >
> > tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)host);
> >
> > ret = request_irq(irq, atmci_interrupt, 0, dev_name(&pdev->dev), host);
> > - if (ret)
> > + if (ret) {
> > + clk_disable_unprepare(host->mck);
> > return ret;
> > + }
> >
> > /* Get MCI capabilities and set operations according to it */
> > atmci_get_cap(host);
> > @@ -2449,6 +2449,12 @@ static int __init atmci_probe(struct platform_device *pdev)
> >
> > setup_timer(&host->timer, atmci_timeout_timer, (unsigned long)host);
> >
> > + pm_runtime_get_noresume(&pdev->dev);
> > + pm_runtime_set_active(&pdev->dev);
> > + pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_DELAY);
> > + pm_runtime_use_autosuspend(&pdev->dev);
> > + pm_runtime_enable(&pdev->dev);
> > +
> > /* We need at least one slot to succeed */
> > nr_slots = 0;
> > ret = -ENODEV;
> > @@ -2491,6 +2497,9 @@ static int __init atmci_probe(struct platform_device *pdev)
> > "Atmel MCI controller at 0x%08lx irq %d, %u slots\n",
> > host->mapbase, irq, nr_slots);
> >
> > + pm_runtime_mark_last_busy(&host->pdev->dev);
> > + pm_runtime_put_autosuspend(&pdev->dev);
> > +
> > return 0;
> >
> > err_dma_alloc:
> > @@ -2499,6 +2508,11 @@ err_dma_alloc:
> > atmci_cleanup_slot(host->slot[i], i);
> > }
> > err_init_slot:
> > + clk_disable_unprepare(host->mck);
> > +
> > + pm_runtime_disable(&pdev->dev);
> > + pm_runtime_put_noidle(&pdev->dev);
> > +
> > del_timer_sync(&host->timer);
> > if (host->dma.chan)
> > dma_release_channel(host->dma.chan);
> > @@ -2511,6 +2525,8 @@ static int __exit atmci_remove(struct platform_device *pdev)
> > struct atmel_mci *host = platform_get_drvdata(pdev);
> > unsigned int i;
> >
> > + pm_runtime_get_sync(&pdev->dev);
> > +
> > if (host->buffer)
> > dma_free_coherent(&pdev->dev, host->buf_size,
> > host->buffer, host->buf_phys_addr);
> > @@ -2520,11 +2536,9 @@ static int __exit atmci_remove(struct platform_device *pdev)
> > atmci_cleanup_slot(host->slot[i], i);
> > }
> >
> > - clk_prepare_enable(host->mck);
> > atmci_writel(host, ATMCI_IDR, ~0UL);
> > atmci_writel(host, ATMCI_CR, ATMCI_CR_MCIDIS);
> > atmci_readl(host, ATMCI_SR);
> > - clk_disable_unprepare(host->mck);
> >
> > del_timer_sync(&host->timer);
> > if (host->dma.chan)
> > @@ -2532,14 +2546,44 @@ static int __exit atmci_remove(struct platform_device *pdev)
> >
> > free_irq(platform_get_irq(pdev, 0), host);
> >
> > + clk_disable_unprepare(host->mck);
> > +
> > + pm_runtime_disable(&pdev->dev);
> > + pm_runtime_put_noidle(&pdev->dev);
> > +
> > + return 0;
> > +}
> > +
> > +#ifdef CONFIG_PM
> > +static int atmci_runtime_suspend(struct device *dev)
> > +{
> > + struct atmel_mci *host = dev_get_drvdata(dev);
> > +
> > + clk_disable_unprepare(host->mck);
> > +
> > return 0;
> > }
> >
> > +static int atmci_runtime_resume(struct device *dev)
> > +{
> > + struct atmel_mci *host = dev_get_drvdata(dev);
> > +
> > + return clk_prepare_enable(host->mck);
> > +}
> > +
> > +static const struct dev_pm_ops atmci_dev_pm_ops = {
> > + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > + pm_runtime_force_resume)
> > + SET_PM_RUNTIME_PM_OPS(atmci_runtime_suspend, atmci_runtime_resume, NULL)
> > +};
> > +#endif
> > +
> > static struct platform_driver atmci_driver = {
> > .remove = __exit_p(atmci_remove),
> > .driver = {
> > .name = "atmel_mci",
> > .of_match_table = of_match_ptr(atmci_dt_ids),
> > + .pm = &atmci_dev_pm_ops,
> > },
> > };
> >
> > --
> > 1.7.9.5
> >
--
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Next message: Stephane Eranian: "Re: [PATCH 3/5] perf, x86: Add Broadwell core support"
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In reply to: Ulf Hansson: "Re: [PATCH v2] mmc: atmel-mci: add runtime pm support"
Next in thread: Ulf Hansson: "Re: [PATCH v2] mmc: atmel-mci: add runtime pm support"
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