2 files changed, 206 insertions, 18 deletions

diff --git a/drivers/regulator/wm831x-dcdc.c b/drivers/regulator/wm831x-dcdc.c
index 2eefc1a0cf0..0a6577577e8 100644
--- a/drivers/regulator/wm831x-dcdc.c
+++ b/drivers/regulator/wm831x-dcdc.c
@@ -19,6 +19,8 @@
 #include <linux/i2c.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/gpio.h>
 
 #include <linux/mfd/wm831x/core.h>
 #include <linux/mfd/wm831x/regulator.h>
@@ -39,6 +41,7 @@
 #define WM831X_DCDC_CONTROL_2     1
 #define WM831X_DCDC_ON_CONFIG     2
 #define WM831X_DCDC_SLEEP_CONTROL 3
+#define WM831X_DCDC_DVS_CONTROL   4
 
 /*
  * Shared
@@ -50,6 +53,10 @@ struct wm831x_dcdc {
         int base;
         struct wm831x *wm831x;
         struct regulator_dev *regulator;
+        int dvs_gpio;
+        int dvs_gpio_state;
+        int on_vsel;
+        int dvs_vsel;
 };
 
 static int wm831x_dcdc_is_enabled(struct regulator_dev *rdev)
@@ -240,11 +247,9 @@ static int wm831x_buckv_list_voltage(struct regulator_dev *rdev,
         return -EINVAL;
 }
 
-static int wm831x_buckv_set_voltage_int(struct regulator_dev *rdev, int reg,
-                                         int min_uV, int max_uV)
+static int wm831x_buckv_select_min_voltage(struct regulator_dev *rdev,
+                                           int min_uV, int max_uV)
 {
-        struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
-        struct wm831x *wm831x = dcdc->wm831x;
         u16 vsel;
 
         if (min_uV < 600000)
@@ -257,39 +262,126 @@ static int wm831x_buckv_set_voltage_int(struct regulator_dev *rdev, int reg,
         if (wm831x_buckv_list_voltage(rdev, vsel) > max_uV)
                 return -EINVAL;
 
-        return wm831x_set_bits(wm831x, reg, WM831X_DC1_ON_VSEL_MASK, vsel);
+        return vsel;
+}
+
+static int wm831x_buckv_select_max_voltage(struct regulator_dev *rdev,
+                                           int min_uV, int max_uV)
+{
+        u16 vsel;
+
+        if (max_uV < 600000 || max_uV > 1800000)
+                return -EINVAL;
+
+        vsel = ((max_uV - 600000) / 12500) + 8;
+
+        if (wm831x_buckv_list_voltage(rdev, vsel) < min_uV ||
+            wm831x_buckv_list_voltage(rdev, vsel) < max_uV)
+                return -EINVAL;
+
+        return vsel;
+}
+
+static int wm831x_buckv_set_dvs(struct regulator_dev *rdev, int state)
+{
+        struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+
+        if (state == dcdc->dvs_gpio_state)
+                return 0;
+
+        dcdc->dvs_gpio_state = state;
+        gpio_set_value(dcdc->dvs_gpio, state);
+
+        /* Should wait for DVS state change to be asserted if we have
+         * a GPIO for it, for now assume the device is configured
+         * for the fastest possible transition.
+         */
+
+        return 0;
 }
 
 static int wm831x_buckv_set_voltage(struct regulator_dev *rdev,
-                                     int min_uV, int max_uV)
+                                    int min_uV, int max_uV)
 {
         struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
-        u16 reg = dcdc->base + WM831X_DCDC_ON_CONFIG;
+        struct wm831x *wm831x = dcdc->wm831x;
+        int on_reg = dcdc->base + WM831X_DCDC_ON_CONFIG;
+        int dvs_reg = dcdc->base + WM831X_DCDC_DVS_CONTROL;
+        int vsel, ret;
+
+        vsel = wm831x_buckv_select_min_voltage(rdev, min_uV, max_uV);
+        if (vsel < 0)
+                return vsel;
+
+        /* If this value is already set then do a GPIO update if we can */
+        if (dcdc->dvs_gpio && dcdc->on_vsel == vsel)
+                return wm831x_buckv_set_dvs(rdev, 0);
+
+        if (dcdc->dvs_gpio && dcdc->dvs_vsel == vsel)
+                return wm831x_buckv_set_dvs(rdev, 1);
+
+        /* Always set the ON status to the minimum voltage */
+        ret = wm831x_set_bits(wm831x, on_reg, WM831X_DC1_ON_VSEL_MASK, vsel);
+        if (ret < 0)
+                return ret;
+        dcdc->on_vsel = vsel;
+
+        if (!dcdc->dvs_gpio)
+                return ret;
+
+        /* Kick the voltage transition now */
+        ret = wm831x_buckv_set_dvs(rdev, 0);
+        if (ret < 0)
+                return ret;
+
+        /* Set the high voltage as the DVS voltage.  This is optimised
+         * for CPUfreq usage, most processors will keep the maximum
+         * voltage constant and lower the minimum with the frequency. */
+        vsel = wm831x_buckv_select_max_voltage(rdev, min_uV, max_uV);
+        if (vsel < 0) {
+                /* This should never happen - at worst the same vsel
+                 * should be chosen */
+                WARN_ON(vsel < 0);
+                return 0;
+        }
+
+        /* Don't bother if it's the same VSEL we're already using */
+        if (vsel == dcdc->on_vsel)
+                return 0;
 
-        return wm831x_buckv_set_voltage_int(rdev, reg, min_uV, max_uV);
+        ret = wm831x_set_bits(wm831x, dvs_reg, WM831X_DC1_DVS_VSEL_MASK, vsel);
+        if (ret == 0)
+                dcdc->dvs_vsel = vsel;
+        else
+                dev_warn(wm831x->dev, "Failed to set DCDC DVS VSEL: %d\n",
+                         ret);
+
+        return 0;
 }
 
 static int wm831x_buckv_set_suspend_voltage(struct regulator_dev *rdev,
-                                             int uV)
+                                            int uV)
 {
         struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
+        struct wm831x *wm831x = dcdc->wm831x;
         u16 reg = dcdc->base + WM831X_DCDC_SLEEP_CONTROL;
+        int vsel;
+
+        vsel = wm831x_buckv_select_min_voltage(rdev, uV, uV);
+        if (vsel < 0)
+                return vsel;
 
-        return wm831x_buckv_set_voltage_int(rdev, reg, uV, uV);
+        return wm831x_set_bits(wm831x, reg, WM831X_DC1_SLP_VSEL_MASK, vsel);
 }
 
 static int wm831x_buckv_get_voltage(struct regulator_dev *rdev)
 {
         struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
-        struct wm831x *wm831x = dcdc->wm831x;
-        u16 reg = dcdc->base + WM831X_DCDC_ON_CONFIG;
-        int val;
 
-        val = wm831x_reg_read(wm831x, reg);
-        if (val < 0)
-                return val;
-
-        return wm831x_buckv_list_voltage(rdev, val & WM831X_DC1_ON_VSEL_MASK);
+        if (dcdc->dvs_gpio && dcdc->dvs_gpio_state)
+                return wm831x_buckv_list_voltage(rdev, dcdc->dvs_vsel);
+        else
+                return wm831x_buckv_list_voltage(rdev, dcdc->on_vsel);
 }
 
 /* Current limit options */
@@ -346,6 +438,64 @@ static struct regulator_ops wm831x_buckv_ops = {
         .set_suspend_mode = wm831x_dcdc_set_suspend_mode,
 };
 
+/*
+ * Set up DVS control.  We just log errors since we can still run
+ * (with reduced performance) if we fail.
+ */
+static __devinit void wm831x_buckv_dvs_init(struct wm831x_dcdc *dcdc,
+                                            struct wm831x_buckv_pdata *pdata)
+{
+        struct wm831x *wm831x = dcdc->wm831x;
+        int ret;
+        u16 ctrl;
+
+        if (!pdata || !pdata->dvs_gpio)
+                return;
+
+        switch (pdata->dvs_control_src) {
+        case 1:
+                ctrl = 2 << WM831X_DC1_DVS_SRC_SHIFT;
+                break;
+        case 2:
+                ctrl = 3 << WM831X_DC1_DVS_SRC_SHIFT;
+                break;
+        default:
+                dev_err(wm831x->dev, "Invalid DVS control source %d for %s\n",
+                        pdata->dvs_control_src, dcdc->name);
+                return;
+        }
+
+        ret = wm831x_set_bits(wm831x, dcdc->base + WM831X_DCDC_DVS_CONTROL,
+                              WM831X_DC1_DVS_SRC_MASK, ctrl);
+        if (ret < 0) {
+                dev_err(wm831x->dev, "Failed to set %s DVS source: %d\n",
+                        dcdc->name, ret);
+                return;
+        }
+
+        ret = gpio_request(pdata->dvs_gpio, "DCDC DVS");
+        if (ret < 0) {
+                dev_err(wm831x->dev, "Failed to get %s DVS GPIO: %d\n",
+                        dcdc->name, ret);
+                return;
+        }
+
+        /* gpiolib won't let us read the GPIO status so pick the higher
+         * of the two existing voltages so we take it as platform data.
+         */
+        dcdc->dvs_gpio_state = pdata->dvs_init_state;
+
+        ret = gpio_direction_output(pdata->dvs_gpio, dcdc->dvs_gpio_state);
+        if (ret < 0) {
+                dev_err(wm831x->dev, "Failed to enable %s DVS GPIO: %d\n",
+                        dcdc->name, ret);
+                gpio_free(pdata->dvs_gpio);
+                return;
+        }
+
+        dcdc->dvs_gpio = pdata->dvs_gpio;
+}
+
 static __devinit int wm831x_buckv_probe(struct platform_device *pdev)
 {
         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
@@ -384,6 +534,23 @@ static __devinit int wm831x_buckv_probe(struct platform_device *pdev)
         dcdc->desc.ops = &wm831x_buckv_ops;
         dcdc->desc.owner = THIS_MODULE;
 
+        ret = wm831x_reg_read(wm831x, dcdc->base + WM831X_DCDC_ON_CONFIG);
+        if (ret < 0) {
+                dev_err(wm831x->dev, "Failed to read ON VSEL: %d\n", ret);
+                goto err;
+        }
+        dcdc->on_vsel = ret & WM831X_DC1_ON_VSEL_MASK;
+
+        ret = wm831x_reg_read(wm831x, dcdc->base + WM831X_DCDC_ON_CONFIG);
+        if (ret < 0) {
+                dev_err(wm831x->dev, "Failed to read DVS VSEL: %d\n", ret);
+                goto err;
+        }
+        dcdc->dvs_vsel = ret & WM831X_DC1_DVS_VSEL_MASK;
+
+        if (pdata->dcdc[id])
+                wm831x_buckv_dvs_init(dcdc, pdata->dcdc[id]->driver_data);
+
         dcdc->regulator = regulator_register(&dcdc->desc, &pdev->dev,
                                              pdata->dcdc[id], dcdc);
         if (IS_ERR(dcdc->regulator)) {
@@ -422,6 +589,8 @@ err_uv:
 err_regulator:
         regulator_unregister(dcdc->regulator);
 err:
+        if (dcdc->dvs_gpio)
+                gpio_free(dcdc->dvs_gpio);
         kfree(dcdc);
         return ret;
 }
@@ -434,6 +603,8 @@ static __devexit int wm831x_buckv_remove(struct platform_device *pdev)
         wm831x_free_irq(wm831x, platform_get_irq_byname(pdev, "HC"), dcdc);
         wm831x_free_irq(wm831x, platform_get_irq_byname(pdev, "UV"), dcdc);
         regulator_unregister(dcdc->regulator);
+        if (dcdc->dvs_gpio)
+                gpio_free(dcdc->dvs_gpio);
         kfree(dcdc);
 
         return 0;
diff --git a/include/linux/mfd/wm831x/pdata.h b/include/linux/mfd/wm831x/pdata.h
index 415c228743d..fd322aca33b 100644
--- a/include/linux/mfd/wm831x/pdata.h
+++ b/include/linux/mfd/wm831x/pdata.h
@@ -41,6 +41,23 @@ struct wm831x_battery_pdata {
         int timeout;        /** Charge cycle timeout, in minutes */
 };
 
+/**
+ * Configuration for the WM831x DC-DC BuckWise convertors.  This
+ * should be passed as driver_data in the regulator_init_data.
+ *
+ * Currently all the configuration is for the fast DVS switching
+ * support of the devices.  This allows MFPs on the device to be
+ * configured as an input to switch between two output voltages,
+ * allowing voltage transitions without the expense of an access over
+ * I2C or SPI buses.
+ */
+struct wm831x_buckv_pdata {
+        int dvs_gpio;        /** CPU GPIO to use for DVS switching */
+        int dvs_control_src; /** Hardware DVS source to use (1 or 2) */
+        int dvs_init_state;  /** DVS state to expect on startup */
+        int dvs_state_gpio;  /** CPU GPIO to use for monitoring status */
+};
+
 /* Sources for status LED configuration.  Values are register values
  * plus 1 to allow for a zero default for preserve.
  */