ARM: OMAP3: mmc-twl4030 voltage cleanup

Correct twl4030 MMC power switching:  fix voltage ranges reported
for each slot, and handle them fully.

 Lies corrected:
  - MMC-1 doesn't support the 2.6-2.7 Volt range
  - MMC-2 can't normally support anything except 1.8V
 Omissions corrected
  - MMC-1 *does* handle the 2.8-2.9 Volt range
  - MMC-2 can handle 2.5-3.2 Volt cards, given a transceiver

Add transciever support for MMC-2; enable it for Overo and Pandora.
(Depends on something else to have set up pinmuxing for control
signals instead of as MMC2_DAT4..7 pins.)

Also shrink twl4030_hsmmc_info a smidgeon ... padding is all gone.

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

4 files changed, 84 insertions, 48 deletions

diff --git a/arch/arm/mach-omap2/board-omap3pandora.c b/arch/arm/mach-omap2/board-omap3pandora.c
index b3196107afdb..7a46a6563a58 100644
--- a/arch/arm/mach-omap2/board-omap3pandora.c
+++ b/arch/arm/mach-omap2/board-omap3pandora.c
@@ -53,6 +53,7 @@ static struct twl4030_hsmmc_info omap3pandora_mmc[] = {
                 .gpio_cd        = -EINVAL,
                 .gpio_wp        = 127,
                 .ext_clock      = 1,
+                .transceiver    = true,
         },
         {}      /* Terminator */
 };
diff --git a/arch/arm/mach-omap2/board-overo.c b/arch/arm/mach-omap2/board-overo.c
index b92313c8b84b..9c14324d8c68 100644
--- a/arch/arm/mach-omap2/board-overo.c
+++ b/arch/arm/mach-omap2/board-overo.c
@@ -214,6 +214,7 @@ static struct twl4030_hsmmc_info mmc[] __initdata = {
                 .wires          = 4,
                 .gpio_cd        = -EINVAL,
                 .gpio_wp        = -EINVAL,
+                .transceiver    = true,
         },
         {}      /* Terminator */
 };
diff --git a/arch/arm/mach-omap2/mmc-twl4030.c b/arch/arm/mach-omap2/mmc-twl4030.c
index 84cac87537a3..df1539e2cd07 100644
--- a/arch/arm/mach-omap2/mmc-twl4030.c
+++ b/arch/arm/mach-omap2/mmc-twl4030.c
@@ -44,6 +44,7 @@
 #define VMMC2_315V              0x0c
 #define VMMC2_300V              0x0b
 #define VMMC2_285V              0x0a
+#define VMMC2_280V              0x09
 #define VMMC2_260V              0x08
 #define VMMC2_185V              0x06
 #define VMMC2_DEDICATED         0x2E
@@ -166,56 +167,73 @@ static int twl_mmc_resume(struct device *dev, int slot)
 /*
  * Sets the MMC voltage in twl4030
  */
+
+#define MMC1_OCR        (MMC_VDD_165_195 \
+                |MMC_VDD_28_29|MMC_VDD_29_30|MMC_VDD_30_31|MMC_VDD_31_32)
+#define MMC2_OCR        (MMC_VDD_165_195 \
+                |MMC_VDD_25_26|MMC_VDD_26_27|MMC_VDD_27_28 \
+                |MMC_VDD_28_29|MMC_VDD_29_30|MMC_VDD_30_31|MMC_VDD_31_32)
+
 static int twl_mmc_set_voltage(struct twl_mmc_controller *c, int vdd)
 {
         int ret;
         u8 vmmc, dev_grp_val;
 
-        switch (1 << vdd) {
-        case MMC_VDD_35_36:
-        case MMC_VDD_34_35:
-        case MMC_VDD_33_34:
-        case MMC_VDD_32_33:
-        case MMC_VDD_31_32:
-        case MMC_VDD_30_31:
-                if (c->twl_vmmc_dev_grp == VMMC1_DEV_GRP)
-                        vmmc = VMMC1_315V;
-                else
-                        vmmc = VMMC2_315V;
-                break;
-        case MMC_VDD_29_30:
-                if (c->twl_vmmc_dev_grp == VMMC1_DEV_GRP)
-                        vmmc = VMMC1_315V;
-                else
-                        vmmc = VMMC2_300V;
-                break;
-        case MMC_VDD_27_28:
-        case MMC_VDD_26_27:
-                if (c->twl_vmmc_dev_grp == VMMC1_DEV_GRP)
-                        vmmc = VMMC1_285V;
-                else
-                        vmmc = VMMC2_285V;
-                break;
-        case MMC_VDD_25_26:
-        case MMC_VDD_24_25:
-        case MMC_VDD_23_24:
-        case MMC_VDD_22_23:
-        case MMC_VDD_21_22:
-        case MMC_VDD_20_21:
-                if (c->twl_vmmc_dev_grp == VMMC1_DEV_GRP)
-                        vmmc = VMMC1_285V;
-                else
-                        vmmc = VMMC2_260V;
-                break;
-        case MMC_VDD_165_195:
-                if (c->twl_vmmc_dev_grp == VMMC1_DEV_GRP)
+        if (c->twl_vmmc_dev_grp == VMMC1_DEV_GRP) {
+                /* VMMC1:  max 220 mA.  And for 8-bit mode,
+                 * VSIM:  max 50 mA
+                 */
+                switch (1 << vdd) {
+                case MMC_VDD_165_195:
                         vmmc = VMMC1_185V;
-                else
+                        /* and VSIM_180V */
+                        break;
+                case MMC_VDD_28_29:
+                        vmmc = VMMC1_285V;
+                        /* and VSIM_280V */
+                        break;
+                case MMC_VDD_29_30:
+                case MMC_VDD_30_31:
+                        vmmc = VMMC1_300V;
+                        /* and VSIM_300V */
+                        break;
+                case MMC_VDD_31_32:
+                        vmmc = VMMC1_315V;
+                        /* error if VSIM needed */
+                        break;
+                default:
+                        vmmc = 0;
+                        break;
+                }
+        } else if (c->twl_vmmc_dev_grp == VMMC2_DEV_GRP) {
+                /* VMMC2:  max 100 mA */
+                switch (1 << vdd) {
+                case MMC_VDD_165_195:
                         vmmc = VMMC2_185V;
-                break;
-        default:
-                vmmc = 0;
-                break;
+                        break;
+                case MMC_VDD_25_26:
+                case MMC_VDD_26_27:
+                        vmmc = VMMC2_260V;
+                        break;
+                case MMC_VDD_27_28:
+                        vmmc = VMMC2_280V;
+                        break;
+                case MMC_VDD_28_29:
+                        vmmc = VMMC2_285V;
+                        break;
+                case MMC_VDD_29_30:
+                case MMC_VDD_30_31:
+                        vmmc = VMMC2_300V;
+                        break;
+                case MMC_VDD_31_32:
+                        vmmc = VMMC2_315V;
+                        break;
+                default:
+                        vmmc = 0;
+                        break;
+                }
+        } else {
+                return 0;
         }
 
         if (vmmc)
@@ -242,6 +260,14 @@ static int twl_mmc1_set_power(struct device *dev, int slot, int power_on,
         struct twl_mmc_controller *c = &hsmmc[0];
         struct omap_mmc_platform_data *mmc = dev->platform_data;
 
+        /*
+         * Assume we power both OMAP VMMC1 (for CMD, CLK, DAT0..3) and the
+         * card using the same TWL VMMC1 supply (hsmmc[0]); OMAP has both
+         * 1.8V and 3.0V modes, controlled by the PBIAS register.
+         *
+         * In 8-bit modes, OMAP VMMC1A (for DAT4..7) needs a supply, which
+         * is most naturally TWL VSIM; those pins also use PBIAS.
+         */
         if (power_on) {
                 if (cpu_is_omap2430()) {
                         reg = omap_ctrl_readl(OMAP243X_CONTROL_DEVCONF1);
@@ -298,6 +324,12 @@ static int twl_mmc2_set_power(struct device *dev, int slot, int power_on, int vd
         struct twl_mmc_controller *c = &hsmmc[1];
         struct omap_mmc_platform_data *mmc = dev->platform_data;
 
+        /*
+         * Assume TWL VMMC2 (hsmmc[1]) is used only to power the card ... OMAP
+         * VDDS is used to power the pins, optionally with a transceiver to
+         * support cards using voltages other than VDDS (1.8V nominal).  When a
+         * transceiver is used, DAT3..7 are muxed as transceiver control pins.
+         */
         if (power_on) {
                 if (mmc->slots[0].internal_clock) {
                         u32 reg;
@@ -353,10 +385,6 @@ void __init twl4030_mmc_init(struct twl4030_hsmmc_info *controllers)
                                 c->mmc, 1);
                 mmc->slots[0].name = twl->name;
                 mmc->nr_slots = 1;
-                mmc->slots[0].ocr_mask = MMC_VDD_165_195 |
-                                        MMC_VDD_26_27 | MMC_VDD_27_28 |
-                                        MMC_VDD_29_30 |
-                                        MMC_VDD_30_31 | MMC_VDD_31_32;
                 mmc->slots[0].wires = c->wires;
                 mmc->slots[0].internal_clock = !c->ext_clock;
                 mmc->dma_mask = 0xffffffff;
@@ -392,9 +420,14 @@ void __init twl4030_mmc_init(struct twl4030_hsmmc_info *controllers)
                 switch (c->mmc) {
                 case 1:
                         mmc->slots[0].set_power = twl_mmc1_set_power;
+                        mmc->slots[0].ocr_mask = MMC1_OCR;
                         break;
                 case 2:
                         mmc->slots[0].set_power = twl_mmc2_set_power;
+                        if (c->transceiver)
+                                mmc->slots[0].ocr_mask = MMC2_OCR;
+                        else
+                                mmc->slots[0].ocr_mask = MMC_VDD_165_195;
                         break;
                 default:
                         pr_err("MMC%d configuration not supported!\n", c->mmc);
diff --git a/arch/arm/mach-omap2/mmc-twl4030.h b/arch/arm/mach-omap2/mmc-twl4030.h
index e1c8076400ca..380dde7bcfe3 100644
--- a/arch/arm/mach-omap2/mmc-twl4030.h
+++ b/arch/arm/mach-omap2/mmc-twl4030.h
@@ -9,9 +9,10 @@
 struct twl4030_hsmmc_info {
         u8      mmc;            /* controller 1/2/3 */
         u8      wires;          /* 1/4/8 wires */
+        bool    transceiver;    /* MMC-2 option */
+        bool    ext_clock;      /* use external pin for input clock */
         int     gpio_cd;        /* or -EINVAL */
         int     gpio_wp;        /* or -EINVAL */
-        int     ext_clock:1;    /* use external pin for input clock */
 };
 
 #if     defined(CONFIG_TWL4030_CORE) && \