[PATCH v3] mmc: sdhci-s3c: ensure non-transaction of bus before clk_disable

[Seungwon Jeon <tgih.jun@samsung.com>]

clock shoud be supplied during bus transaction. This patch defers
clk_disabe in runtime_suspend if cmd/data line is used.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
---
V3: Removed the error message. (reported by Fengguang Wu)

 drivers/mmc/host/sdhci-s3c.c |   13 +++++++++----
 drivers/mmc/host/sdhci.c     |   20 ++++----------------
 drivers/mmc/host/sdhci.h     |   12 ++++++++++++
 3 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index a54dd5d..d680c0b 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -847,12 +847,17 @@ static int sdhci_s3c_runtime_suspend(struct device *dev)
 	struct sdhci_host *host = dev_get_drvdata(dev);
 	struct sdhci_s3c *ourhost = to_s3c(host);
 	struct clk *busclk = ourhost->clk_io;
-	int ret;
+	int ret = 0;
 
-	ret = sdhci_runtime_suspend_host(host);
+	if (!(readl(host->ioaddr + SDHCI_PRESENT_STATE) &
+			(SDHCI_CMD_INHIBIT | SDHCI_DATA_INHIBIT))) {
+		ret = sdhci_runtime_suspend_host(host);
+		clk_disable_unprepare(ourhost->clk_bus[ourhost->cur_clk]);
+		clk_disable_unprepare(busclk);
+	} else {
+		sdhci_runtime_pm_put(host);
+	}
 
-	clk_disable_unprepare(ourhost->clk_bus[ourhost->cur_clk]);
-	clk_disable_unprepare(busclk);
 	return ret;
 }
 
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index c7851c0..59b60e1 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -54,20 +54,6 @@ static void sdhci_finish_command(struct sdhci_host *);
 static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);
 static void sdhci_tuning_timer(unsigned long data);
 
-#ifdef CONFIG_PM_RUNTIME
-static int sdhci_runtime_pm_get(struct sdhci_host *host);
-static int sdhci_runtime_pm_put(struct sdhci_host *host);
-#else
-static inline int sdhci_runtime_pm_get(struct sdhci_host *host)
-{
-	return 0;
-}
-static inline int sdhci_runtime_pm_put(struct sdhci_host *host)
-{
-	return 0;
-}
-#endif
-
 static void sdhci_dumpregs(struct sdhci_host *host)
 {
 	pr_debug(DRIVER_NAME ": =========== REGISTER DUMP (%s)===========\n",
@@ -2538,16 +2524,18 @@ EXPORT_SYMBOL_GPL(sdhci_enable_irq_wakeups);
 
 #ifdef CONFIG_PM_RUNTIME
 
-static int sdhci_runtime_pm_get(struct sdhci_host *host)
+int sdhci_runtime_pm_get(struct sdhci_host *host)
 {
 	return pm_runtime_get_sync(host->mmc->parent);
 }
+EXPORT_SYMBOL_GPL(sdhci_runtime_pm_get);
 
-static int sdhci_runtime_pm_put(struct sdhci_host *host)
+int sdhci_runtime_pm_put(struct sdhci_host *host)
 {
 	pm_runtime_mark_last_busy(host->mmc->parent);
 	return pm_runtime_put_autosuspend(host->mmc->parent);
 }
+EXPORT_SYMBOL_GPL(sdhci_runtime_pm_put);
 
 int sdhci_runtime_suspend_host(struct sdhci_host *host)
 {
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 71a4a7e..02edce1 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -385,8 +385,20 @@ extern void sdhci_enable_irq_wakeups(struct sdhci_host *host);
 #endif
 
 #ifdef CONFIG_PM_RUNTIME
+extern int sdhci_runtime_pm_get(struct sdhci_host *host);
+extern int sdhci_runtime_pm_put(struct sdhci_host *host);
 extern int sdhci_runtime_suspend_host(struct sdhci_host *host);
 extern int sdhci_runtime_resume_host(struct sdhci_host *host);
+#else
+static inline int sdhci_runtime_pm_get(struct sdhci_host *host)
+{
+	return 0;
+}
+
+static inline int sdhci_runtime_pm_put(struct sdhci_host *host)
+{
+	return 0;
+}
 #endif
 
 #endif /* __SDHCI_HW_H */
-- 
1.7.0.4