omap: RX51: Remux to pull eMMC lines down when powering off

It has been discovered that, when eMMC is powered off, current
will flow from OMAP eMMC data pull-ups to the eMMC voltage supply.
Configuring pads for OMAP off-mode does not help because eMMC is
powered off independently of OMAP off-mode.  Hence the pads are
now re-configured when eMMC is powered on or off.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

3 files changed, 52 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/board-rx51-peripherals.c b/arch/arm/mach-omap2/board-rx51-peripherals.c
index ab07ca2d4085..4377a4cf36eb 100644
--- a/arch/arm/mach-omap2/board-rx51-peripherals.c
+++ b/arch/arm/mach-omap2/board-rx51-peripherals.c
@@ -209,6 +209,46 @@ static struct twl4030_madc_platform_data rx51_madc_data = {
         .irq_line               = 1,
 };
 
+/* Enable input logic and pull all lines up when eMMC is on. */
+static struct omap_board_mux rx51_mmc2_on_mux[] = {
+        OMAP3_MUX(SDMMC2_CMD, OMAP_PIN_INPUT_PULLUP | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT0, OMAP_PIN_INPUT_PULLUP | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT1, OMAP_PIN_INPUT_PULLUP | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT2, OMAP_PIN_INPUT_PULLUP | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT3, OMAP_PIN_INPUT_PULLUP | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT4, OMAP_PIN_INPUT_PULLUP | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT5, OMAP_PIN_INPUT_PULLUP | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT6, OMAP_PIN_INPUT_PULLUP | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT7, OMAP_PIN_INPUT_PULLUP | OMAP_MUX_MODE0),
+        { .reg_offset = OMAP_MUX_TERMINATOR },
+};
+
+/* Disable input logic and pull all lines down when eMMC is off. */
+static struct omap_board_mux rx51_mmc2_off_mux[] = {
+        OMAP3_MUX(SDMMC2_CMD, OMAP_PULL_ENA | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT0, OMAP_PULL_ENA | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT1, OMAP_PULL_ENA | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT2, OMAP_PULL_ENA | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT3, OMAP_PULL_ENA | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT4, OMAP_PULL_ENA | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT5, OMAP_PULL_ENA | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT6, OMAP_PULL_ENA | OMAP_MUX_MODE0),
+        OMAP3_MUX(SDMMC2_DAT7, OMAP_PULL_ENA | OMAP_MUX_MODE0),
+        { .reg_offset = OMAP_MUX_TERMINATOR },
+};
+
+/*
+ * Current flows to eMMC when eMMC is off and the data lines are pulled up,
+ * so pull them down. N.B. we pull 8 lines because we are using 8 lines.
+ */
+static void rx51_mmc2_remux(struct device *dev, int slot, int power_on)
+{
+        if (power_on)
+                omap_mux_write_array(rx51_mmc2_on_mux);
+        else
+                omap_mux_write_array(rx51_mmc2_off_mux);
+}
+
 static struct omap2_hsmmc_info mmc[] __initdata = {
         {
                 .name           = "external",
@@ -222,11 +262,12 @@ static struct omap2_hsmmc_info mmc[] __initdata = {
         {
                 .name           = "internal",
                 .mmc            = 2,
-                .wires          = 8,
+                .wires          = 8, /* See also rx51_mmc2_remux */
                 .gpio_cd        = -EINVAL,
                 .gpio_wp        = -EINVAL,
                 .nonremovable   = true,
                 .power_saving   = true,
+                .remux          = rx51_mmc2_remux,
         },
         {}      /* Terminator */
 };
diff --git a/arch/arm/mach-omap2/hsmmc.c b/arch/arm/mach-omap2/hsmmc.c
index cc7e77f09268..4a05c3722d54 100644
--- a/arch/arm/mach-omap2/hsmmc.c
+++ b/arch/arm/mach-omap2/hsmmc.c
@@ -48,6 +48,9 @@ static void hsmmc1_before_set_reg(struct device *dev, int slot,
         u32 reg, prog_io;
         struct omap_mmc_platform_data *mmc = dev->platform_data;
 
+        if (mmc->slots[0].remux)
+                mmc->slots[0].remux(dev, slot, power_on);
+
         /*
          * Assume we power both OMAP VMMC1 (for CMD, CLK, DAT0..3) and the
          * card with Vcc regulator (from twl4030 or whatever).  OMAP has both
@@ -121,6 +124,9 @@ static void hsmmc23_before_set_reg(struct device *dev, int slot,
 {
         struct omap_mmc_platform_data *mmc = dev->platform_data;
 
+        if (mmc->slots[0].remux)
+                mmc->slots[0].remux(dev, slot, power_on);
+
         if (power_on) {
                 /* Only MMC2 supports a CLKIN */
                 if (mmc->slots[0].internal_clock) {
@@ -185,6 +191,8 @@ void __init omap2_hsmmc_init(struct omap2_hsmmc_info *controllers)
                 mmc->slots[0].switch_pin = c->gpio_cd;
                 mmc->slots[0].gpio_wp = c->gpio_wp;
 
+                mmc->slots[0].remux = c->remux;
+
                 if (c->cover_only)
                         mmc->slots[0].cover = 1;
 
diff --git a/arch/arm/mach-omap2/hsmmc.h b/arch/arm/mach-omap2/hsmmc.h
index e946b5f79be1..f641f592ffad 100644
--- a/arch/arm/mach-omap2/hsmmc.h
+++ b/arch/arm/mach-omap2/hsmmc.h
@@ -19,6 +19,8 @@ struct omap2_hsmmc_info {
         char    *name;          /* or NULL for default */
         struct device *dev;     /* returned: pointer to mmc adapter */
         int     ocr_mask;       /* temporary HACK */
+        /* Remux (pad configuation) when powering on/off */
+        void (*remux)(struct device *dev, int slot, int power_on);
 };
 
 #if defined(CONFIG_MMC_OMAP_HS) || defined(CONFIG_MMC_OMAP_HS_MODULE)