regulator: pwm: add support for enable and mode gpio

Add supports for:
- enable gpio which enable/disable the regulator.
- idle gpio which is require to set the regulator mode.

Change-Id: I9b31514542462bf2a3dd024cf799fbbe18ef86f4
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/361549

1 files changed, 93 insertions, 4 deletions

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index 4192114f0cac..416a158a162a 100644
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -21,6 +21,9 @@
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/regulator/driver.h>
@@ -40,6 +43,9 @@ struct pwm_regulator {
 	unsigned int		uV_step;
 	unsigned int		n_voltages;
 	unsigned int		curr_selector;
+	int			enable_gpio;
+	int			idle_gpio;
+	int			standby_gpio;
 };
 
 static int pwm_regulator_set_voltage_sel(
@@ -77,12 +83,49 @@ static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev)
 	return preg->curr_selector;
 }
 
+static int pwm_regulator_set_mode(struct regulator_dev *rdev,
+	unsigned int mode)
+{
+	struct pwm_regulator *preg = rdev_get_drvdata(rdev);
+
+	if (!gpio_is_valid(preg->idle_gpio))
+		return -EINVAL;
+
+	switch (mode) {
+	case REGULATOR_MODE_IDLE:
+		gpio_set_value(preg->idle_gpio, 0);
+		break;
+	case REGULATOR_MODE_NORMAL:
+		gpio_set_value(preg->idle_gpio, 1);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static unsigned int pwm_regulator_get_mode(struct regulator_dev *rdev)
+{
+	struct pwm_regulator *preg = rdev_get_drvdata(rdev);
+
+	if (!gpio_is_valid(preg->idle_gpio))
+		return 0;
+
+	if (gpio_get_value(preg->idle_gpio))
+		return REGULATOR_MODE_NORMAL;
+	else
+		return REGULATOR_MODE_IDLE;
+}
+
 static struct regulator_ops pwm_regulator_ops = {
 	.set_voltage_sel = pwm_regulator_set_voltage_sel,
 	.get_voltage_sel = pwm_regulator_get_voltage_sel,
 	.list_voltage = regulator_list_voltage_linear,
 	.map_voltage = regulator_map_voltage_linear,
 	.set_voltage_time_sel   = regulator_set_voltage_time_sel,
+	.set_mode = pwm_regulator_set_mode,
+	.get_mode = pwm_regulator_get_mode,
 };
 
 static int pwm_regulator_parse_dt(struct device *dev,
@@ -106,6 +149,26 @@ static int pwm_regulator_parse_dt(struct device *dev,
 		return ret;
 	}
 
+	preg->enable_gpio = of_get_named_gpio(node, "enable-gpio", 0);
+	if ((preg->enable_gpio < 0) && (preg->enable_gpio != -ENOENT)) {
+		dev_err(dev, "Enable gpio not available, %d\n",
+			preg->enable_gpio);
+		return preg->enable_gpio;
+	}
+
+	preg->idle_gpio = of_get_named_gpio(node, "idle-gpio", 0);
+	if ((preg->idle_gpio < 0) && (preg->idle_gpio != -ENOENT)) {
+		dev_err(dev, "Idle gpio not available, %d\n", preg->idle_gpio);
+		return preg->idle_gpio;
+	}
+
+	preg->standby_gpio = of_get_named_gpio(node, "standby-gpio", 0);
+	if ((preg->standby_gpio < 0) && (preg->standby_gpio != -ENOENT)) {
+		dev_err(dev, "Standby gpio not available, %d\n",
+			preg->standby_gpio);
+		return preg->standby_gpio;
+	}
+
 	preg->min_uV = preg->rinit_data->constraints.min_uV;
 	preg->max_uV = preg->rinit_data->constraints.max_uV;
 	return 0;
@@ -119,21 +182,26 @@ static int pwm_regulator_verify_patform_data(struct pwm_regulator *preg)
 	if (!preg->period)
 		return -EINVAL;
 
-	if (preg->period % preg->n_voltages) {
+	if (preg->n_voltages < 2) {
+		dev_err(dev, "Number of volatges is not correct\n");
+		return -EINVAL;
+	}
+
+	if (preg->period % (preg->n_voltages - 1)) {
 		dev_err(dev, "PWM Period must multiple of n_voltages\n");
 		return -EINVAL;
 	}
-	preg->pulse_time = preg->period / preg->n_voltages;
+	preg->pulse_time = preg->period / (preg->n_voltages - 1);
 	if (!preg->pulse_time) {
 		dev_err(dev, "Pulse time is invalid\n");
 		return -EINVAL;
 	}
 
-	if ((preg->max_uV - preg->min_uV) % preg->n_voltages) {
+	if ((preg->max_uV - preg->min_uV) % (preg->n_voltages - 1)) {
 		dev_err(dev, "Min/Max is not proper to get step voltage\n");
 		return -EINVAL;
 	}
-	preg->uV_step = (preg->max_uV - preg->min_uV) / preg->n_voltages;
+	preg->uV_step = (preg->max_uV - preg->min_uV) / (preg->n_voltages - 1);
 	return 0;
 }
 static int pwm_regulator_probe(struct platform_device *pdev)
@@ -174,6 +242,20 @@ static int pwm_regulator_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	if (gpio_is_valid(preg->idle_gpio)) {
+		ret = devm_gpio_request_one(&pdev->dev, preg->idle_gpio,
+				GPIOF_OUT_INIT_HIGH, "pwm-reg-idle-gpio");
+		if (ret < 0) {
+			dev_err(&pdev->dev, "Idle gpio request failed\n");
+			return ret;
+		}
+		preg->rinit_data->constraints.valid_modes_mask |=
+						REGULATOR_MODE_IDLE |
+						REGULATOR_MODE_NORMAL;
+		preg->rinit_data->constraints.valid_ops_mask |=
+						REGULATOR_CHANGE_MODE;
+	}
+
 	preg->desc.name = "regulator-pwm";
 	preg->desc.id = -1;
 	preg->desc.ops = &pwm_regulator_ops;
@@ -185,6 +267,13 @@ static int pwm_regulator_probe(struct platform_device *pdev)
 	preg->desc.linear_min_sel = 0;
 	preg->desc.n_voltages = preg->n_voltages;
 
+	if (gpio_is_valid(preg->enable_gpio)) {
+		config.ena_gpio = preg->enable_gpio;
+		if (preg->rinit_data->constraints.always_on ||
+			preg->rinit_data->constraints.boot_on)
+			config.ena_gpio_flags = GPIOF_OUT_INIT_HIGH;
+	}
+
 	config.dev = &pdev->dev;
 	config.init_data = preg->rinit_data;
 	config.driver_data = preg;