ARM: 7218/1: mmc: mmci: Provide option to configure bus signal direction

The ST Micro variant supports bus signal direction indication. A new
member in the variant struct is added for this.

Moreover the actual signal direction configuration is board specific,
thus the amba mmci platform data is extended with a new member to be
able provide mmci with these specific board configurations.

This patch is based upon a patch from Sebastian Rasmussen.

Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Rasmussen <sebastian.rasmussen@stericsson.com>
Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 7cc89beee87f..eb11ce61941d 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -54,6 +54,7 @@ static unsigned int fmax = 515633;
  * @st_clkdiv: true if using a ST-specific clock divider algorithm
  * @blksz_datactrl16: true if Block size is at b16..b30 position in datactrl register
  * @pwrreg_powerup: power up value for MMCIPOWER register
+ * @signal_direction: input/out direction of bus signals can be indicated
  */
 struct variant_data {
         unsigned int            clkreg;
@@ -65,6 +66,7 @@ struct variant_data {
         bool                    st_clkdiv;
         bool                    blksz_datactrl16;
         u32                     pwrreg_powerup;
+        bool                    signal_direction;
 };
 
 static struct variant_data variant_arm = {
@@ -88,6 +90,7 @@ static struct variant_data variant_u300 = {
         .datalength_bits        = 16,
         .sdio                   = true,
         .pwrreg_powerup         = MCI_PWR_ON,
+        .signal_direction       = true,
 };
 
 static struct variant_data variant_ux500 = {
@@ -99,6 +102,7 @@ static struct variant_data variant_ux500 = {
         .sdio                   = true,
         .st_clkdiv              = true,
         .pwrreg_powerup         = MCI_PWR_ON,
+        .signal_direction       = true,
 };
 
 static struct variant_data variant_ux500v2 = {
@@ -111,6 +115,7 @@ static struct variant_data variant_ux500v2 = {
         .st_clkdiv              = true,
         .blksz_datactrl16       = true,
         .pwrreg_powerup         = MCI_PWR_ON,
+        .signal_direction       = true,
 };
 
 /*
@@ -1057,6 +1062,22 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
                 break;
         }
 
+        if (variant->signal_direction && ios->power_mode != MMC_POWER_OFF) {
+                /*
+                 * The ST Micro variant has some additional bits
+                 * indicating signal direction for the signals in
+                 * the SD/MMC bus and feedback-clock usage.
+                 */
+                pwr |= host->plat->sigdir;
+
+                if (ios->bus_width == MMC_BUS_WIDTH_4)
+                        pwr &= ~MCI_ST_DATA74DIREN;
+                else if (ios->bus_width == MMC_BUS_WIDTH_1)
+                        pwr &= (~MCI_ST_DATA74DIREN &
+                                ~MCI_ST_DATA31DIREN &
+                                ~MCI_ST_DATA2DIREN);
+        }
+
         if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN) {
                 if (host->hw_designer != AMBA_VENDOR_ST)
                         pwr |= MCI_ROD;