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path: root/drivers/regulator/wm831x-dcdc.c
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Diffstat (limited to 'drivers/regulator/wm831x-dcdc.c')
-rw-r--r--drivers/regulator/wm831x-dcdc.c207
1 files changed, 189 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;