ARM: OMAP3: mmc-twl4030 uses regulator framework

Decouple the HSMMC glue from the twl4030 as the only
regulator provider, using the regulator framework instead.
This makes the glue's "mmc-twl4030" name become a complete
misnomer ... this code could probably all migrate into the
HSMMC driver now.

Tested on 3430SDP (SD and low-voltage MMC) and Beagle (SD),
plus some other boards (including Overo) after they were
converted to set up MMC regulators properly.

Eventually all boards should just associate a regulator with
each MMC controller they use.  In some cases (Overo MMC2 and
Pandora MMC3, at least) that would be a fixed-voltage regulator
with no real software control.  As a temporary hack (pending
regulator-next updates to make the "fixed.c" regulator become
usable) there's a new ocr_mask field for those boards.

Patch updated with a fix for disabling vcc_aux by
Adrian Hunter <adrian.hunter@nokia.com>

Cc: Pierre Ossman <drzeus-list@drzeus.cx>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>

2 files changed, 115 insertions, 168 deletions

diff --git a/arch/arm/mach-omap2/mmc-twl4030.c b/arch/arm/mach-omap2/mmc-twl4030.c
index dc40b3e72206..9756a878fd90 100644
--- a/arch/arm/mach-omap2/mmc-twl4030.c
+++ b/arch/arm/mach-omap2/mmc-twl4030.c
@@ -16,8 +16,8 @@
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/gpio.h>
-#include <linux/i2c/twl4030.h>
-#include <linux/regulator/machine.h>
+#include <linux/mmc/host.h>
+#include <linux/regulator/consumer.h>
 
 #include <mach/hardware.h>
 #include <mach/control.h>
@@ -26,31 +26,9 @@
 
 #include "mmc-twl4030.h"
 
-#if defined(CONFIG_TWL4030_CORE) && \
-        (defined(CONFIG_MMC_OMAP_HS) || defined(CONFIG_MMC_OMAP_HS_MODULE))
 
-#define LDO_CLR                 0x00
-#define VSEL_S2_CLR             0x40
-
-#define VMMC1_DEV_GRP           0x27
-#define VMMC1_CLR               0x00
-#define VMMC1_315V              0x03
-#define VMMC1_300V              0x02
-#define VMMC1_285V              0x01
-#define VMMC1_185V              0x00
-#define VMMC1_DEDICATED         0x2A
-
-#define VMMC2_DEV_GRP           0x2B
-#define VMMC2_CLR               0x40
-#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
-
-#define VMMC_DEV_GRP_P1         0x20
+#if defined(CONFIG_REGULATOR) && \
+        (defined(CONFIG_MMC_OMAP_HS) || defined(CONFIG_MMC_OMAP_HS_MODULE))
 
 static u16 control_pbias_offset;
 static u16 control_devconf1_offset;
@@ -59,19 +37,16 @@ static u16 control_devconf1_offset;
 
 static struct twl_mmc_controller {
         struct omap_mmc_platform_data   *mmc;
-        u8              twl_vmmc_dev_grp;
-        u8              twl_mmc_dedicated;
-        char            name[HSMMC_NAME_LEN + 1];
-} hsmmc[OMAP34XX_NR_MMC] = {
-        {
-                .twl_vmmc_dev_grp               = VMMC1_DEV_GRP,
-                .twl_mmc_dedicated              = VMMC1_DEDICATED,
-        },
-        {
-                .twl_vmmc_dev_grp               = VMMC2_DEV_GRP,
-                .twl_mmc_dedicated              = VMMC2_DEDICATED,
-        },
-};
+        /* Vcc == configured supply
+         * Vcc_alt == optional
+         *   -  MMC1, supply for DAT4..DAT7
+         *   -  MMC2/MMC2, external level shifter voltage supply, for
+         *      chip (SDIO, eMMC, etc) or transceiver (MMC2 only)
+         */
+        struct regulator                *vcc;
+        struct regulator                *vcc_aux;
+        char                            name[HSMMC_NAME_LEN + 1];
+} hsmmc[OMAP34XX_NR_MMC];
 
 static int twl_mmc_card_detect(int irq)
 {
@@ -117,16 +92,60 @@ static int twl_mmc_late_init(struct device *dev)
         int ret = 0;
         int i;
 
-        ret = gpio_request(mmc->slots[0].switch_pin, "mmc_cd");
-        if (ret)
-                goto done;
-        ret = gpio_direction_input(mmc->slots[0].switch_pin);
-        if (ret)
-                goto err;
+        /* MMC/SD/SDIO doesn't require a card detect switch */
+        if (gpio_is_valid(mmc->slots[0].switch_pin)) {
+                ret = gpio_request(mmc->slots[0].switch_pin, "mmc_cd");
+                if (ret)
+                        goto done;
+                ret = gpio_direction_input(mmc->slots[0].switch_pin);
+                if (ret)
+                        goto err;
+        }
 
+        /* require at least main regulator */
         for (i = 0; i < ARRAY_SIZE(hsmmc); i++) {
                 if (hsmmc[i].name == mmc->slots[0].name) {
+                        struct regulator *reg;
+
                         hsmmc[i].mmc = mmc;
+
+                        reg = regulator_get(dev, "vmmc");
+                        if (IS_ERR(reg)) {
+                                dev_dbg(dev, "vmmc regulator missing\n");
+                                /* HACK: until fixed.c regulator is usable,
+                                 * we don't require a main regulator
+                                 * for MMC2 or MMC3
+                                 */
+                                if (i != 0)
+                                        break;
+                                ret = PTR_ERR(reg);
+                                goto err;
+                        }
+                        hsmmc[i].vcc = reg;
+                        mmc->slots[0].ocr_mask = mmc_regulator_get_ocrmask(reg);
+
+                        /* allow an aux regulator */
+                        reg = regulator_get(dev, "vmmc_aux");
+                        hsmmc[i].vcc_aux = IS_ERR(reg) ? NULL : reg;
+
+                        /* UGLY HACK:  workaround regulator framework bugs.
+                         * When the bootloader leaves a supply active, it's
+                         * initialized with zero usecount ... and we can't
+                         * disable it without first enabling it.  Until the
+                         * framework is fixed, we need a workaround like this
+                         * (which is safe for MMC, but not in general).
+                         */
+                        if (regulator_is_enabled(hsmmc[i].vcc) > 0) {
+                                regulator_enable(hsmmc[i].vcc);
+                                regulator_disable(hsmmc[i].vcc);
+                        }
+                        if (hsmmc[i].vcc_aux) {
+                                if (regulator_is_enabled(reg) > 0) {
+                                        regulator_enable(reg);
+                                        regulator_disable(reg);
+                                }
+                        }
+
                         break;
                 }
         }
@@ -173,96 +192,6 @@ static int twl_mmc_resume(struct device *dev, int slot)
 #define twl_mmc_resume  NULL
 #endif
 
-/*
- * 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 = 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,
-                 * VSIM:  max 50 mA
-                 */
-                switch (1 << vdd) {
-                case MMC_VDD_165_195:
-                        vmmc = VMMC1_185V;
-                        /* 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:
-                        return -EINVAL;
-                }
-        } 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;
-                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:
-                        return -EINVAL;
-                }
-        } else {
-                return -EINVAL;
-        }
-
-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 || !vdd)
-                return ret;
-
-        ret = twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER,
-                                        vmmc, c->twl_mmc_dedicated);
-
-        return ret;
-}
-
 static int twl_mmc1_set_power(struct device *dev, int slot, int power_on,
                                 int vdd)
 {
@@ -273,11 +202,13 @@ static int twl_mmc1_set_power(struct device *dev, int slot, int power_on,
 
         /*
          * 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
+         * card with Vcc regulator (from twl4030 or whatever).  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.
+         *
+         * FIXME handle VMMC1A as needed ...
          */
         if (power_on) {
                 if (cpu_is_omap2430()) {
@@ -300,7 +231,7 @@ static int twl_mmc1_set_power(struct device *dev, int slot, int power_on,
                 reg &= ~OMAP2_PBIASLITEPWRDNZ0;
                 omap_ctrl_writel(reg, control_pbias_offset);
 
-                ret = twl_mmc_set_voltage(c, vdd);
+                ret = mmc_regulator_set_ocr(c->vcc, vdd);
 
                 /* 100ms delay required for PBIAS configuration */
                 msleep(100);
@@ -316,7 +247,7 @@ static int twl_mmc1_set_power(struct device *dev, int slot, int power_on,
                 reg &= ~OMAP2_PBIASLITEPWRDNZ0;
                 omap_ctrl_writel(reg, control_pbias_offset);
 
-                ret = twl_mmc_set_voltage(c, 0);
+                ret = mmc_regulator_set_ocr(c->vcc, 0);
 
                 /* 100ms delay required for PBIAS configuration */
                 msleep(100);
@@ -329,19 +260,33 @@ static int twl_mmc1_set_power(struct device *dev, int slot, int power_on,
         return ret;
 }
 
-static int twl_mmc2_set_power(struct device *dev, int slot, int power_on, int vdd)
+static int twl_mmc23_set_power(struct device *dev, int slot, int power_on, int vdd)
 {
-        int ret;
+        int ret = 0;
         struct twl_mmc_controller *c = &hsmmc[1];
         struct omap_mmc_platform_data *mmc = dev->platform_data;
 
+        /* If we don't see a Vcc regulator, assume it's a fixed
+         * voltage always-on regulator.
+         */
+        if (!c->vcc)
+                return 0;
+
         /*
-         * Assume TWL VMMC2 (hsmmc[1]) is used only to power the card ... OMAP
+         * Assume Vcc regulator 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.
+         *
+         * In some cases this regulator won't support enable/disable;
+         * e.g. it's a fixed rail for a WLAN chip.
+         *
+         * In other cases vcc_aux switches interface power.  Example, for
+         * eMMC cards it represents VccQ.  Sometimes transceivers or SDIO
+         * chips/cards need an interface voltage rail too.
          */
         if (power_on) {
+                /* only MMC2 supports a CLKIN */
                 if (mmc->slots[0].internal_clock) {
                         u32 reg;
 
@@ -349,24 +294,23 @@ static int twl_mmc2_set_power(struct device *dev, int slot, int power_on, int vd
                         reg |= OMAP2_MMCSDIO2ADPCLKISEL;
                         omap_ctrl_writel(reg, control_devconf1_offset);
                 }
-                ret = twl_mmc_set_voltage(c, vdd);
+                ret = mmc_regulator_set_ocr(c->vcc, vdd);
+                /* enable interface voltage rail, if needed */
+                if (ret == 0 && c->vcc_aux) {
+                        ret = regulator_enable(c->vcc_aux);
+                        if (ret < 0)
+                                ret = mmc_regulator_set_ocr(c->vcc, 0);
+                }
         } else {
-                ret = twl_mmc_set_voltage(c, 0);
+                if (c->vcc_aux && (ret = regulator_is_enabled(c->vcc_aux)) > 0)
+                        ret = regulator_disable(c->vcc_aux);
+                if (ret == 0)
+                        ret = mmc_regulator_set_ocr(c->vcc, 0);
         }
 
         return ret;
 }
 
-static int twl_mmc3_set_power(struct device *dev, int slot, int power_on,
-                int vdd)
-{
-        /*
-         * Assume MMC3 has self-powered device connected, for example on-board
-         * chip with external power source.
-         */
-        return 0;
-}
-
 static struct omap_mmc_platform_data *hsmmc_data[OMAP34XX_NR_MMC] __initdata;
 
 void __init twl4030_mmc_init(struct twl4030_hsmmc_info *controllers)
@@ -412,10 +356,10 @@ void __init twl4030_mmc_init(struct twl4030_hsmmc_info *controllers)
                 mmc->slots[0].wires = c->wires;
                 mmc->slots[0].internal_clock = !c->ext_clock;
                 mmc->dma_mask = 0xffffffff;
+                mmc->init = twl_mmc_late_init;
 
-                /* note: twl4030 card detect GPIOs normally switch VMMCx ... */
+                /* note: twl4030 card detect GPIOs can disable VMMCx ... */
                 if (gpio_is_valid(c->gpio_cd)) {
-                        mmc->init = twl_mmc_late_init;
                         mmc->cleanup = twl_mmc_cleanup;
                         mmc->suspend = twl_mmc_suspend;
                         mmc->resume = twl_mmc_resume;
@@ -439,26 +383,28 @@ void __init twl4030_mmc_init(struct twl4030_hsmmc_info *controllers)
                 } else
                         mmc->slots[0].gpio_wp = -EINVAL;
 
-                /* NOTE:  we assume OMAP's MMC1 and MMC2 use
-                 * the TWL4030's VMMC1 and VMMC2, respectively;
-                 * and that MMC3 device has it's own power source.
+                /* NOTE:  MMC slots should have a Vcc regulator set up.
+                 * This may be from a TWL4030-family chip, another
+                 * controllable regulator, or a fixed supply.
+                 *
+                 * temporary HACK: ocr_mask instead of fixed supply
                  */
+                mmc->slots[0].ocr_mask = c->ocr_mask;
 
                 switch (c->mmc) {
                 case 1:
+                        /* on-chip level shifting via PBIAS0/PBIAS1 */
                         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;
+                        if (c->ext_clock)
+                                c->transceiver = 1;
+                        if (c->transceiver && c->wires > 4)
+                                c->wires = 4;
+                        /* FALLTHROUGH */
                 case 3:
-                        mmc->slots[0].set_power = twl_mmc3_set_power;
-                        mmc->slots[0].ocr_mask = MMC_VDD_165_195;
+                        /* off-chip level shifting, or none */
+                        mmc->slots[0].set_power = twl_mmc23_set_power;
                         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 ea59e8624290..3807c45c9a6c 100644
--- a/arch/arm/mach-omap2/mmc-twl4030.h
+++ b/arch/arm/mach-omap2/mmc-twl4030.h
@@ -16,9 +16,10 @@ struct twl4030_hsmmc_info {
         int     gpio_wp;        /* or -EINVAL */
         char    *name;          /* or NULL for default */
         struct device *dev;     /* returned: pointer to mmc adapter */
+        int     ocr_mask;       /* temporary HACK */
 };
 
-#if     defined(CONFIG_TWL4030_CORE) && \
+#if defined(CONFIG_REGULATOR) && \
         (defined(CONFIG_MMC_OMAP) || defined(CONFIG_MMC_OMAP_MODULE) || \
          defined(CONFIG_MMC_OMAP_HS) || defined(CONFIG_MMC_OMAP_HS_MODULE))