[RFC,PATCHv3,2/3] mmc: sdhci: use ios->clock to know when sdhci is idle

Commit Message

Pierre Tardy March 1, 2011, 6:15 p.m. UTC

None

Patch

diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index f167a55..1b5e70b 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -1089,6 +1089,9 @@  static int __devinit sdhci_pci_probe(struct pci_dev *pdev,
 
 		chip->slots[i] = slot;
 	}
+	pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_suspend_ignore_children(&pdev->dev, 1);
 	pm_runtime_put_noidle(&pdev->dev);
 	return 0;
 
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index cd79a28..735c3f7 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -20,6 +20,7 @@ 
 #include <linux/slab.h>
 #include <linux/scatterlist.h>
 #include <linux/regulator/consumer.h>
+#include <linux/pm_runtime.h>
 
 #include <linux/leds.h>
 
@@ -1161,6 +1162,7 @@  static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
 	struct sdhci_host *host;
 	unsigned long flags;
+	unsigned int lastclock;
 	u8 ctrl;
 
 	host = mmc_priv(mmc);
@@ -1171,6 +1173,27 @@  static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		goto out;
 
 	/*
+	 * get/put runtime_pm usage counter at ios->clock transitions
+	 * We need to do it before any other chip access, as sdhci could
+	 * be power gated
+	 */
+	lastclock = host->iosclock;
+	host->iosclock = ios->clock;
+	if (lastclock == 0 && ios->clock != 0) {
+		spin_unlock_irqrestore(&host->lock, flags);
+		pm_runtime_get_sync(host->mmc->parent);
+		spin_lock_irqsave(&host->lock, flags);
+	} else if (lastclock != 0 && ios->clock == 0) {
+		spin_unlock_irqrestore(&host->lock, flags);
+		pm_runtime_mark_last_busy(host->mmc->parent);
+		pm_runtime_put_autosuspend(host->mmc->parent);
+		spin_lock_irqsave(&host->lock, flags);
+	}
+	/* no need to configure the rest.. */
+	if (host->iosclock == 0)
+		goto out;
+
+	/*
 	 * Reset the chip on each power off.
 	 * Should clear out any weird states.
 	 */
@@ -1244,6 +1267,8 @@  static int sdhci_get_ro(struct mmc_host *mmc)
 	int is_readonly;
 
 	host = mmc_priv(mmc);
+	/* this function is called before set_ios... */
+	pm_runtime_get_sync(mmc->parent);
 
 	spin_lock_irqsave(&host->lock, flags);
 
@@ -1257,6 +1282,7 @@  static int sdhci_get_ro(struct mmc_host *mmc)
 
 	spin_unlock_irqrestore(&host->lock, flags);
 
+	pm_runtime_put_autosuspend(mmc->parent);
 	/* This quirk needs to be replaced by a callback-function later */
 	return host->quirks & SDHCI_QUIRK_INVERTED_WRITE_PROTECT ?
 		!is_readonly : is_readonly;
@@ -1268,6 +1294,7 @@  static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable)
 	unsigned long flags;
 
 	host = mmc_priv(mmc);
+	pm_runtime_get_sync(mmc->parent);
 
 	spin_lock_irqsave(&host->lock, flags);
 
@@ -1282,6 +1309,7 @@  out:
 	mmiowb();
 
 	spin_unlock_irqrestore(&host->lock, flags);
+	pm_runtime_put_autosuspend(mmc->parent);
 }
 
 static const struct mmc_host_ops sdhci_ops = {
@@ -1766,6 +1794,7 @@  struct sdhci_host *sdhci_alloc_host(struct device *dev,
 
 	host = mmc_priv(mmc);
 	host->mmc = mmc;
+	host->iosclock = 0;
 
 	return host;
 }
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index 83bd9f7..a38d040 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -116,6 +116,7 @@  struct sdhci_host {
 	unsigned int timeout_clk;	/* Timeout freq (KHz) */
 
 	unsigned int clock;	/* Current clock (MHz) */
+	unsigned int iosclock;	/* Last clock asked via set_ios  */
 	u8 pwr;			/* Current voltage */
 
 	struct mmc_request *mrq;	/* Current request */