[PATCH] mmc: sdhci-s3c: fix missing clock for gpio card-detect

["Heiko Stübner" <heiko@sntech.de>]

Commit 2abeb5c5ded2 (Add clk_(enable/disable) in runtime suspend/resume)
added the capability to stop the clocks when the device is runtime
suspended, but forgot to handle the case of the card-detect using
an external gpio.

Therefore in the case that runtime-pm is enabled, start the io-clock
when a card is inserted and stop it again once it is removed.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 drivers/mmc/host/sdhci-s3c.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

This _should_ go into 3.7 because currently it causes a regression there.
Nevertheless it applies to both 3.7-rc6 and linux-next.

I also tried to use pm_runtime_get_sync (and _put) there, but it didn't
seem to work and the clock was still missing. With the changes in this
patch, the gpio-card-detect works again on my machine - all of insert,
remove and reinsert.

diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index a54dd5d..c9ec725 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -373,18 +373,25 @@ static struct sdhci_ops sdhci_s3c_ops = {
 static void sdhci_s3c_notify_change(struct platform_device *dev, int state)
 {
 	struct sdhci_host *host = platform_get_drvdata(dev);
+	struct sdhci_s3c *sc = sdhci_priv(host);
 	unsigned long flags;
 
 	if (host) {
 		spin_lock_irqsave(&host->lock, flags);
 		if (state) {
 			dev_dbg(&dev->dev, "card inserted.\n");
+#ifdef CONFIG_PM_RUNTIME
+			clk_prepare_enable(sc->clk_io);
+#endif
 			host->flags &= ~SDHCI_DEVICE_DEAD;
 			host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
 		} else {
 			dev_dbg(&dev->dev, "card removed.\n");
 			host->flags |= SDHCI_DEVICE_DEAD;
 			host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
+#ifdef CONFIG_PM_RUNTIME
+			clk_disable_unprepare(sc->clk_io);
+#endif
 		}
 		tasklet_schedule(&host->card_tasklet);
 		spin_unlock_irqrestore(&host->lock, flags);
-- 
1.7.2.3