ARM: OMAP3: mmc-twl4030 fix for vmmc = 0

Resolve longstanding issue noted by Adrian Hunter:  confusion
between settting VSEL=0 (which is 1.8V on MMC1) and poweroff.

Also, leave VSEL alone if we're just powering the regulator off.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/mach-omap2/mmc-twl4030.c b/arch/arm/mach-omap2/mmc-twl4030.c
index d9fad8d..d434214 100644 (file)
--- a/arch/arm/mach-omap2/mmc-twl4030.c
+++ b/arch/arm/mach-omap2/mmc-twl4030.c
@@ -178,7 +178,10 @@ static int twl_mmc_resume(struct device *dev, int slot)
 static int twl_mmc_set_voltage(struct twl_mmc_controller *c, int vdd)
 {
        int ret;
-       u8 vmmc, dev_grp_val;
+       u8 vmmc = 0, dev_grp_val;
+
+       if (!vdd)
+               goto doit;
 
        if (c->twl_vmmc_dev_grp == VMMC1_DEV_GRP) {
                /* VMMC1:  max 220 mA.  And for 8-bit mode,
@@ -203,8 +206,7 @@ static int twl_mmc_set_voltage(struct twl_mmc_controller *c, int vdd)
                        /* error if VSIM needed */
                        break;
                default:
-                       vmmc = 0;
-                       break;
+                       return -EINVAL;
                }
        } else if (c->twl_vmmc_dev_grp == VMMC2_DEV_GRP) {
                /* VMMC2:  max 100 mA */
@@ -230,21 +232,21 @@ static int twl_mmc_set_voltage(struct twl_mmc_controller *c, int vdd)
                        vmmc = VMMC2_315V;
                        break;
                default:
-                       vmmc = 0;
-                       break;
+                       return -EINVAL;
                }
        } else {
-               return 0;
+               return -EINVAL;
        }
 
-       if (vmmc)
+doit:
+       if (vdd)
                dev_grp_val = VMMC_DEV_GRP_P1;  /* Power up */
        else
                dev_grp_val = LDO_CLR;          /* Power down */
 
        ret = twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER,
                                        dev_grp_val, c->twl_vmmc_dev_grp);
-       if (ret)
+       if (ret || !vdd)
                return ret;
 
        ret = twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER,