SDHCI: Add change_clock callback for glue drivers

Add a change_clock callback to allow drivers to update
device specific clock selections and control registers
when there is a change in clock.

Move the main part of sdhci_set_clock() to a new routine
which can be called by the glue drivers to do the sdhci
standard clock management.

Update the sdhci-s3c driver to use this to select the
appropriate clock source when clocks change.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 59c890e7b4c..280f3eafac9 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -907,13 +907,18 @@ static void sdhci_finish_command(struct sdhci_host *host)
 
 static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
 {
+	if (clock == host->clock)
+		return;
+
+	host->ops->change_clock(host, clock);
+}
+
+void sdhci_change_clock(struct sdhci_host *host, unsigned int clock)
+{
 	int div;
 	u16 clk;
 	unsigned long timeout;
 
-	if (clock == host->clock)
-		return;
-
 	writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
 
 	if (clock == 0)
@@ -950,6 +955,8 @@ out:
 	host->clock = clock;
 }
 
+EXPORT_SYMBOL_GPL(sdhci_set_clock);
+
 static void sdhci_set_power(struct sdhci_host *host, unsigned short power)
 {
 	u8 pwr;