mmc: core: Add mmc_power_cycle

Add mmc_power_cycle which can be used to power cycle for instance
SD-cards.

Signed-off-by: Johan Rudholm <[email protected]>
Acked-by: Ulf Hansson <[email protected]>
Tested-by: Wei WANG <[email protected]>
Signed-off-by: Chris Ball <[email protected]>

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 39f28af34cb653475d8f9621d4b4606113a1c423..789056fbfc9333a692dd72d917a065f45bbf9e00 100644 (file)
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1470,6 +1470,14 @@ void mmc_power_off(struct mmc_host *host)
        mmc_host_clk_release(host);
 }
 
+void mmc_power_cycle(struct mmc_host *host)
+{
+       mmc_power_off(host);
+       /* Wait at least 1 ms according to SD spec */
+       mmc_delay(1);
+       mmc_power_up(host);
+}
+
 /*
  * Cleanup when the last reference to the bus operator is dropped.
  */

diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 0272b3284b5efcb4d659e90d32ec1d41fb2ce78a..9007de74d8a9cab7c62b4a98c8bc92a80d113719 100644 (file)
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -45,6 +45,7 @@ int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage,
 void mmc_set_timing(struct mmc_host *host, unsigned int timing);
 void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type);
 void mmc_power_off(struct mmc_host *host);
+void mmc_power_cycle(struct mmc_host *host);
 
 static inline void mmc_delay(unsigned int ms)
 {