[MMC] ios for mmc chip select

Adds a new ios for setting the chip select pin on MMC cards. Needed on
SD controllers which use this pin for other things and therefore cannot
have it pulled high at all times.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 18 insertions, 0 deletions

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 3c5904834fe8..0a8165974ba7 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -457,6 +457,11 @@ static void mmc_idle_cards(struct mmc_host *host)
 {
         struct mmc_command cmd;
 
+        host->ios.chip_select = MMC_CS_HIGH;
+        host->ops->set_ios(host, &host->ios);
+
+        mmc_delay(1);
+
         cmd.opcode = MMC_GO_IDLE_STATE;
         cmd.arg = 0;
         cmd.flags = MMC_RSP_NONE;
@@ -464,6 +469,11 @@ static void mmc_idle_cards(struct mmc_host *host)
         mmc_wait_for_cmd(host, &cmd, 0);
 
         mmc_delay(1);
+
+        host->ios.chip_select = MMC_CS_DONTCARE;
+        host->ops->set_ios(host, &host->ios);
+
+        mmc_delay(1);
 }
 
 /*
@@ -475,6 +485,7 @@ static void mmc_power_up(struct mmc_host *host)
 
         host->ios.vdd = bit;
         host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
+        host->ios.chip_select = MMC_CS_DONTCARE;
         host->ios.power_mode = MMC_POWER_UP;
         host->ops->set_ios(host, &host->ios);
 
@@ -492,6 +503,7 @@ static void mmc_power_off(struct mmc_host *host)
         host->ios.clock = 0;
         host->ios.vdd = 0;
         host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
+        host->ios.chip_select = MMC_CS_DONTCARE;
         host->ios.power_mode = MMC_POWER_OFF;
         host->ops->set_ios(host, &host->ios);
 }
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 9a0893f3249e..30f68c0c8c6e 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -46,6 +46,12 @@ struct mmc_ios {
 #define MMC_BUSMODE_OPENDRAIN   1
 #define MMC_BUSMODE_PUSHPULL    2
 
+        unsigned char   chip_select;            /* SPI chip select */
+
+#define MMC_CS_DONTCARE         0
+#define MMC_CS_HIGH             1
+#define MMC_CS_LOW              2
+
         unsigned char   power_mode;             /* power supply mode */
 
 #define MMC_POWER_OFF           0