omap_hsmmc: Wait for SDBP

It is necessary to wait for bus power before sending
any commands.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 15 insertions, 5 deletions

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 61883093e25b..488f222054f8 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -498,6 +498,19 @@ static irqreturn_t mmc_omap_irq(int irq, void *dev_id)
         return IRQ_HANDLED;
 }
 
+static void set_sd_bus_power(struct mmc_omap_host *host)
+{
+        unsigned long i;
+
+        OMAP_HSMMC_WRITE(host->base, HCTL,
+                         OMAP_HSMMC_READ(host->base, HCTL) | SDBP);
+        for (i = 0; i < loops_per_jiffy; i++) {
+                if (OMAP_HSMMC_READ(host->base, HCTL) & SDBP)
+                        break;
+                cpu_relax();
+        }
+}
+
 /*
  * Switch MMC interface voltage ... only relevant for MMC1.
  *
@@ -554,9 +567,7 @@ static int omap_mmc_switch_opcond(struct mmc_omap_host *host, int vdd)
                 reg_val |= SDVS30;
 
         OMAP_HSMMC_WRITE(host->base, HCTL, reg_val);
-
-        OMAP_HSMMC_WRITE(host->base, HCTL,
-                OMAP_HSMMC_READ(host->base, HCTL) | SDBP);
+        set_sd_bus_power(host);
 
         return 0;
 err:
@@ -942,8 +953,7 @@ static void omap_hsmmc_init(struct mmc_omap_host *host)
         OMAP_HSMMC_WRITE(host->base, SYSCONFIG, value | AUTOIDLE);
 
         /* Set SD bus power bit */
-        value = OMAP_HSMMC_READ(host->base, HCTL);
-        OMAP_HSMMC_WRITE(host->base, HCTL, value | SDBP);
+        set_sd_bus_power(host);
 }
 
 static struct mmc_host_ops mmc_omap_ops = {