1 files changed, 98 insertions, 6 deletions

diff --git a/arch/arm/mach-omap1/board-ams-delta.c b/arch/arm/mach-omap1/board-ams-delta.c
index ce50fe137269..949997c35707 100644
--- a/arch/arm/mach-omap1/board-ams-delta.c
+++ b/arch/arm/mach-omap1/board-ams-delta.c
@@ -18,7 +18,11 @@
 #include <linux/input.h>
 #include <linux/interrupt.h>
 #include <linux/leds.h>
+#include <linux/mutex.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/fixed.h>
+#include <linux/regulator/machine.h>
 #include <linux/serial_8250.h>
 #include <linux/export.h>
 
@@ -237,11 +241,6 @@ static const struct gpio latch_gpios[] __initconst = {
                 .label  = "scard_cmdvcc",
         },
         {
-                .gpio   = AMS_DELTA_GPIO_PIN_MODEM_NRESET,
-                .flags  = GPIOF_OUT_INIT_LOW,
-                .label  = "modem_nreset",
-        },
-        {
                 .gpio   = AMS_DELTA_GPIO_PIN_MODEM_CODEC,
                 .flags  = GPIOF_OUT_INIT_LOW,
                 .label  = "modem_codec",
@@ -258,6 +257,71 @@ static const struct gpio latch_gpios[] __initconst = {
         },
 };
 
+static struct regulator_consumer_supply modem_nreset_consumers[] = {
+        REGULATOR_SUPPLY("RESET#", "serial8250.1"),
+        REGULATOR_SUPPLY("POR", "cx20442-codec"),
+};
+
+static struct regulator_init_data modem_nreset_data = {
+        .constraints            = {
+                .valid_ops_mask         = REGULATOR_CHANGE_STATUS,
+                .boot_on                = 1,
+        },
+        .num_consumer_supplies  = ARRAY_SIZE(modem_nreset_consumers),
+        .consumer_supplies      = modem_nreset_consumers,
+};
+
+static struct fixed_voltage_config modem_nreset_config = {
+        .supply_name            = "modem_nreset",
+        .microvolts             = 3300000,
+        .gpio                   = AMS_DELTA_GPIO_PIN_MODEM_NRESET,
+        .startup_delay          = 25000,
+        .enable_high            = 1,
+        .enabled_at_boot        = 1,
+        .init_data              = &modem_nreset_data,
+};
+
+static struct platform_device modem_nreset_device = {
+        .name   = "reg-fixed-voltage",
+        .id     = -1,
+        .dev    = {
+                .platform_data  = &modem_nreset_config,
+        },
+};
+
+struct modem_private_data {
+        struct regulator *regulator;
+        struct {
+                struct mutex lock;
+                bool enabled;
+        } consumer;
+};
+
+static int regulator_toggle(struct modem_private_data *priv, bool enable)
+{
+        int err = 0;
+
+        mutex_lock(&priv->consumer.lock);
+        if (IS_ERR(priv->regulator)) {
+                err = PTR_ERR(priv->regulator);
+        } else if (enable) {
+                if (!priv->consumer.enabled) {
+                        err = regulator_enable(priv->regulator);
+                        priv->consumer.enabled = true;
+                }
+        } else {
+                if (priv->consumer.enabled) {
+                        err = regulator_disable(priv->regulator);
+                        priv->consumer.enabled = false;
+                }
+        }
+        mutex_unlock(&priv->consumer.lock);
+
+        return err;
+}
+
+static struct modem_private_data modem_priv;
+
 void ams_delta_latch_write(int base, int ngpio, u16 mask, u16 value)
 {
         int bit = 0;
@@ -266,7 +330,10 @@ void ams_delta_latch_write(int base, int ngpio, u16 mask, u16 value)
         for (; bit < ngpio; bit++, bitpos = bitpos << 1) {
                 if (!(mask & bitpos))
                         continue;
-                gpio_set_value(base + bit, (value & bitpos) != 0);
+                else if (base + bit == AMS_DELTA_GPIO_PIN_MODEM_NRESET)
+                        regulator_toggle(&modem_priv, (value & bitpos) != 0);
+                else
+                        gpio_set_value(base + bit, (value & bitpos) != 0);
         }
 }
 EXPORT_SYMBOL(ams_delta_latch_write);
@@ -496,6 +563,12 @@ static int __init late_init(void)
 
         platform_add_devices(late_devices, ARRAY_SIZE(late_devices));
 
+        err = platform_device_register(&modem_nreset_device);
+        if (err) {
+                pr_err("Couldn't register the modem regulator device\n");
+                return err;
+        }
+
         omap_cfg_reg(M14_1510_GPIO2);
         ams_delta_modem_ports[0].irq =
                         gpio_to_irq(AMS_DELTA_GPIO_PIN_MODEM_IRQ);
@@ -507,6 +580,10 @@ static int __init late_init(void)
         }
         gpio_direction_input(AMS_DELTA_GPIO_PIN_MODEM_IRQ);
 
+        /* Initialize the modem_nreset regulator consumer before use */
+        mutex_init(&modem_priv.consumer.lock);
+        modem_priv.regulator = ERR_PTR(-ENODEV);
+
         ams_delta_latch2_write(
                 AMS_DELTA_LATCH2_MODEM_NRESET | AMS_DELTA_LATCH2_MODEM_CODEC,
                 AMS_DELTA_LATCH2_MODEM_NRESET | AMS_DELTA_LATCH2_MODEM_CODEC);
@@ -514,8 +591,23 @@ static int __init late_init(void)
         err = platform_device_register(&ams_delta_modem_device);
         if (err)
                 goto gpio_free;
+
+        /*
+         * Once the modem device is registered, the modem_nreset
+         * regulator can be requested on behalf of that device.
+         * The regulator is used via ams_delta_latch_write()
+         * by the modem and ASoC drivers until updated.
+         */
+        modem_priv.regulator = regulator_get(&ams_delta_modem_device.dev,
+                        "RESET#");
+        if (IS_ERR(modem_priv.regulator)) {
+                err = PTR_ERR(modem_priv.regulator);
+                goto unregister;
+        }
         return 0;
 
+unregister:
+        platform_device_unregister(&ams_delta_modem_device);
 gpio_free:
         gpio_free(AMS_DELTA_GPIO_PIN_MODEM_IRQ);
         return err;