mmc: tmio: maximize power saving

This patch uses runtime PM to allow the system to power down the MMC
controller, when the MMC closk is switched off.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index f0d7c43..ba0d8e6 100644 (file)
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -53,6 +53,8 @@ struct tmio_mmc_host {
        void (*set_clk_div)(struct platform_device *host, int state);
 
        int                     pm_error;
+       /* recognise system-wide suspend in runtime PM methods */
+       bool                    pm_global;
 
        /* pio related stuff */
        struct scatterlist      *sg_ptr;

diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index a2f76ad..221ffb7 100644 (file)
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/drivers/mmc/host/tmio_mmc_pio.c
@@ -546,6 +546,7 @@ out:
 irqreturn_t tmio_mmc_irq(int irq, void *devid)
 {
        struct tmio_mmc_host *host = devid;
+       struct mmc_host *mmc = host->mmc;
        struct tmio_mmc_data *pdata = host->pdata;
        unsigned int ireg, irq_mask, status;
        unsigned int sdio_ireg, sdio_irq_mask, sdio_status;
@@ -567,13 +568,13 @@ irqreturn_t tmio_mmc_irq(int irq, void *devid)
                if (sdio_ireg && !host->sdio_irq_enabled) {
                        pr_warning("tmio_mmc: Spurious SDIO IRQ, disabling! 0x%04x 0x%04x 0x%04x\n",
                                   sdio_status, sdio_irq_mask, sdio_ireg);
-                       tmio_mmc_enable_sdio_irq(host->mmc, 0);
+                       tmio_mmc_enable_sdio_irq(mmc, 0);
                        goto out;
                }
 
-               if (host->mmc->caps & MMC_CAP_SDIO_IRQ &&
+               if (mmc->caps & MMC_CAP_SDIO_IRQ &&
                        sdio_ireg & TMIO_SDIO_STAT_IOIRQ)
-                       mmc_signal_sdio_irq(host->mmc);
+                       mmc_signal_sdio_irq(mmc);
 
                if (sdio_ireg)
                        goto out;
@@ -586,7 +587,9 @@ irqreturn_t tmio_mmc_irq(int irq, void *devid)
        if (ireg & (TMIO_STAT_CARD_INSERT | TMIO_STAT_CARD_REMOVE)) {
                tmio_mmc_ack_mmc_irqs(host, TMIO_STAT_CARD_INSERT |
                        TMIO_STAT_CARD_REMOVE);
-               if (!work_pending(&host->mmc->detect.work))
+               if ((((ireg & TMIO_STAT_CARD_REMOVE) && mmc->card) ||
+                    ((ireg & TMIO_STAT_CARD_INSERT) && !mmc->card)) &&
+                   !work_pending(&mmc->detect.work))
                        mmc_detect_change(host->mmc, msecs_to_jiffies(100));
                goto out;
        }
@@ -743,33 +746,30 @@ static void tmio_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
        spin_unlock_irqrestore(&host->lock, flags);
 
-       if (ios->clock)
-               tmio_mmc_set_clock(host, ios->clock);
-
-       /* Power sequence - OFF -> UP -> ON */
-       if (ios->power_mode == MMC_POWER_UP) {
-               if ((pdata->flags & TMIO_MMC_HAS_COLD_CD) && !pdata->power) {
+       /*
+        * pdata->power == false only if COLD_CD is available, otherwise only
+        * in short time intervals during probing or resuming
+        */
+       if (ios->power_mode == MMC_POWER_ON && ios->clock) {
+               if (!pdata->power) {
                        pm_runtime_get_sync(&host->pdev->dev);
                        pdata->power = true;
                }
+               tmio_mmc_set_clock(host, ios->clock);
                /* power up SD bus */
                if (host->set_pwr)
                        host->set_pwr(host->pdev, 1);
-       } else if (ios->power_mode == MMC_POWER_OFF || !ios->clock) {
-               /* power down SD bus */
-               if (ios->power_mode == MMC_POWER_OFF) {
-                       if (host->set_pwr)
-                               host->set_pwr(host->pdev, 0);
-                       if ((pdata->flags & TMIO_MMC_HAS_COLD_CD) &&
-                           pdata->power) {
-                               pdata->power = false;
-                               pm_runtime_put(&host->pdev->dev);
-                       }
-               }
-               tmio_mmc_clk_stop(host);
-       } else {
                /* start bus clock */
                tmio_mmc_clk_start(host);
+       } else if (ios->power_mode != MMC_POWER_UP) {
+               if (host->set_pwr)
+                       host->set_pwr(host->pdev, 0);
+               if ((pdata->flags & TMIO_MMC_HAS_COLD_CD) &&
+                   pdata->power) {
+                       pdata->power = false;
+                       pm_runtime_put(&host->pdev->dev);
+               }
+               tmio_mmc_clk_stop(host);
        }
 
        switch (ios->bus_width) {
@@ -897,8 +897,10 @@ int __devinit tmio_mmc_host_probe(struct tmio_mmc_host **host,
        tmio_mmc_request_dma(_host, pdata);
 
        /* We have to keep the device powered for its card detection to work */
-       if (!(pdata->flags & TMIO_MMC_HAS_COLD_CD))
+       if (!(pdata->flags & TMIO_MMC_HAS_COLD_CD)) {
+               pdata->power = true;
                pm_runtime_get_noresume(&pdev->dev);
+       }
 
        mmc_add_host(mmc);
 
@@ -975,11 +977,16 @@ int tmio_mmc_host_resume(struct device *dev)
        /* The MMC core will perform the complete set up */
        host->pdata->power = false;
 
+       host->pm_global = true;
        if (!host->pm_error)
                pm_runtime_get_sync(dev);
 
-       tmio_mmc_reset(mmc_priv(mmc));
-       tmio_mmc_request_dma(host, host->pdata);
+       if (host->pm_global) {
+               /* Runtime PM resume callback didn't run */
+               tmio_mmc_reset(host);
+               tmio_mmc_request_dma(host, host->pdata);
+               host->pm_global = false;
+       }
 
        return mmc_resume_host(mmc);
 }
@@ -1000,12 +1007,15 @@ int tmio_mmc_host_runtime_resume(struct device *dev)
        struct tmio_mmc_data *pdata = host->pdata;
 
        tmio_mmc_reset(host);
+       tmio_mmc_request_dma(host, host->pdata);
 
        if (pdata->power) {
                /* Only entered after a card-insert interrupt */
-               tmio_mmc_set_ios(mmc, &mmc->ios);
+               if (!mmc->card)
+                       tmio_mmc_set_ios(mmc, &mmc->ios);
                mmc_detect_change(mmc, msecs_to_jiffies(100));
        }
+       host->pm_global = false;
 
        return 0;
 }