Merge branch 'for-4.8/regulator' into for-next

thierryreding · thierryreding · commit 53de7c26ded7 · 2016-07-25T16:23:40.000+02:00
diff --git a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
@@ -34,20 +34,44 @@ Only required for Voltage Table Mode:
 			    First cell is voltage in microvolts (uV)
 			    Second cell is duty-cycle in percent (%)
 
+Optional properties for Continuous mode:
+- pwm-dutycycle-unit:	Integer value encoding the duty cycle unit. If not
+			defined, <100> is assumed, meaning that
+			pwm-dutycycle-range contains values expressed in
+			percent.
+
+- pwm-dutycycle-range:	Should contain 2 entries. The first entry is encoding
+			the dutycycle for regulator-min-microvolt and the
+			second one the dutycycle for regulator-max-microvolt.
+			Duty cycle values are expressed in pwm-dutycycle-unit.
+			If not defined, <0 100> is assumed.
+
 NB: To be clear, if voltage-table is provided, then the device will be used
 in Voltage Table Mode.  If no voltage-table is provided, then the device will
 be used in Continuous Voltage Mode.
 
+Optional properties:
+--------------------
+- enable-gpios:		GPIO to use to enable/disable the regulator
+
 Any property defined as part of the core regulator binding can also be used.
 (See: ../regulator/regulator.txt)
 
-Continuous Voltage Example:
+Continuous Voltage With Enable GPIO Example:
 	pwm_regulator {
 		compatible = "pwm-regulator;
 		pwms = <&pwm1 0 8448 0>;
+		enable-gpios = <&gpio0 23 GPIO_ACTIVE_HIGH>;
 		regulator-min-microvolt = <1016000>;
 		regulator-max-microvolt = <1114000>;
 		regulator-name = "vdd_logic";
+		/* unit == per-mille */
+		pwm-dutycycle-unit = <1000>;
+		/*
+		 * Inverted PWM logic, and the duty cycle range is limited
+		 * to 30%-70%.
+		 */
+		pwm-dutycycle-range <700 300>; /* */
 	};
 
 Voltage Table Example:
diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
@@ -20,6 +20,13 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/pwm.h>
+#include <linux/gpio/consumer.h>
+
+struct pwm_continuous_reg_data {
+	unsigned int min_uV_dutycycle;
+	unsigned int max_uV_dutycycle;
+	unsigned int dutycycle_unit;
+};
 
 struct pwm_regulator_data {
 	/*  Shared */
@@ -28,6 +35,9 @@ struct pwm_regulator_data {
 	/* Voltage table */
 	struct pwm_voltages *duty_cycle_table;
 
+	/* Continuous mode info */
+	struct pwm_continuous_reg_data continuous;
+
 	/* regulator descriptor */
 	struct regulator_desc desc;
 
@@ -36,8 +46,8 @@ struct pwm_regulator_data {
 
 	int state;
 
-	/* Continuous voltage */
-	int volt_uV;
+	/* Enable GPIO */
+	struct gpio_desc *enb_gpio;
 };
 
 struct pwm_voltages {
@@ -48,27 +58,46 @@ struct pwm_voltages {
 /**
  * Voltage table call-backs
  */
+static void pwm_regulator_init_state(struct regulator_dev *rdev)
+{
+	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
+	struct pwm_state pwm_state;
+	unsigned int dutycycle;
+	int i;
+
+	pwm_get_state(drvdata->pwm, &pwm_state);
+	dutycycle = pwm_get_relative_duty_cycle(&pwm_state, 100);
+
+	for (i = 0; i < rdev->desc->n_voltages; i++) {
+		if (dutycycle == drvdata->duty_cycle_table[i].dutycycle) {
+			drvdata->state = i;
+			return;
+		}
+	}
+}
+
 static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
 
+	if (drvdata->state < 0)
+		pwm_regulator_init_state(rdev);
+
 	return drvdata->state;
 }
 
 static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev,
 					 unsigned selector)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
-	struct pwm_args pargs;
-	int dutycycle;
+	struct pwm_state pstate;
 	int ret;
 
-	pwm_get_args(drvdata->pwm, &pargs);
-
-	dutycycle = (pargs.period *
-		    drvdata->duty_cycle_table[selector].dutycycle) / 100;
+	pwm_init_state(drvdata->pwm, &pstate);
+	pwm_set_relative_duty_cycle(&pstate,
+			drvdata->duty_cycle_table[selector].dutycycle, 100);
 
-	ret = pwm_config(drvdata->pwm, dutycycle, pargs.period);
+	ret = pwm_apply_state(drvdata->pwm, &pstate);
 	if (ret) {
 		dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret);
 		return ret;
@@ -94,6 +123,9 @@ static int pwm_regulator_enable(struct regulator_dev *dev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
 
+	if (drvdata->enb_gpio)
+		gpiod_set_value_cansleep(drvdata->enb_gpio, 1);
+
 	return pwm_enable(drvdata->pwm);
 }
 
@@ -103,71 +135,110 @@ static int pwm_regulator_disable(struct regulator_dev *dev)
 
 	pwm_disable(drvdata->pwm);
 
+	if (drvdata->enb_gpio)
+		gpiod_set_value_cansleep(drvdata->enb_gpio, 0);
+
 	return 0;
 }
 
 static int pwm_regulator_is_enabled(struct regulator_dev *dev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
 
+	if (drvdata->enb_gpio && !gpiod_get_value_cansleep(drvdata->enb_gpio))
+		return false;
+
 	return pwm_is_enabled(drvdata->pwm);
 }
 
 static int pwm_regulator_get_voltage(struct regulator_dev *rdev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
+	unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle;
+	unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle;
+	unsigned int duty_unit = drvdata->continuous.dutycycle_unit;
+	int min_uV = rdev->constraints->min_uV;
+	int max_uV = rdev->constraints->max_uV;
+	int diff_uV = max_uV - min_uV;
+	struct pwm_state pstate;
+	unsigned int diff_duty;
+	unsigned int voltage;
+
+	pwm_get_state(drvdata->pwm, &pstate);
+
+	voltage = pwm_get_relative_duty_cycle(&pstate, duty_unit);
+
+	/*
+	 * The dutycycle for min_uV might be greater than the one for max_uV.
+	 * This is happening when the user needs an inversed polarity, but the
+	 * PWM device does not support inversing it in hardware.
+	 */
+	if (max_uV_duty < min_uV_duty) {
+		voltage = min_uV_duty - voltage;
+		diff_duty = min_uV_duty - max_uV_duty;
+	} else {
+		voltage = voltage - min_uV_duty;
+		diff_duty = max_uV_duty - min_uV_duty;
+	}
+
+	voltage = DIV_ROUND_CLOSEST_ULL((u64)voltage * diff_uV, diff_duty);
 
-	return drvdata->volt_uV;
+	return voltage + min_uV;
 }
 
 static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
-					int min_uV, int max_uV,
-					unsigned *selector)
+				     int req_min_uV, int req_max_uV,
+				     unsigned int *selector)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
+	unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle;
+	unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle;
+	unsigned int duty_unit = drvdata->continuous.dutycycle_unit;
 	unsigned int ramp_delay = rdev->constraints->ramp_delay;
-	struct pwm_args pargs;
-	unsigned int req_diff = min_uV - rdev->constraints->min_uV;
-	unsigned int diff;
-	unsigned int duty_pulse;
-	u64 req_period;
-	u32 rem;
+	int min_uV = rdev->constraints->min_uV;
+	int max_uV = rdev->constraints->max_uV;
+	int diff_uV = max_uV - min_uV;
+	struct pwm_state pstate;
+	int old_uV = pwm_regulator_get_voltage(rdev);
+	unsigned int diff_duty;
+	unsigned int dutycycle;
 	int ret;
 
-	pwm_get_args(drvdata->pwm, &pargs);
-	diff = rdev->constraints->max_uV - rdev->constraints->min_uV;
+	pwm_init_state(drvdata->pwm, &pstate);
 
-	/* First try to find out if we get the iduty cycle time which is
-	 * factor of PWM period time. If (request_diff_to_min * pwm_period)
-	 * is perfect divided by voltage_range_diff then it is possible to
-	 * get duty cycle time which is factor of PWM period. This will help
-	 * to get output voltage nearer to requested value as there is no
-	 * calculation loss.
+	/*
+	 * The dutycycle for min_uV might be greater than the one for max_uV.
+	 * This is happening when the user needs an inversed polarity, but the
+	 * PWM device does not support inversing it in hardware.
 	 */
-	req_period = req_diff * pargs.period;
-	div_u64_rem(req_period, diff, &rem);
-	if (!rem) {
-		do_div(req_period, diff);
-		duty_pulse = (unsigned int)req_period;
-	} else {
-		duty_pulse = (pargs.period / 100) * ((req_diff * 100) / diff);
-	}
+	if (max_uV_duty < min_uV_duty)
+		diff_duty = min_uV_duty - max_uV_duty;
+	else
+		diff_duty = max_uV_duty - min_uV_duty;
+
+	dutycycle = DIV_ROUND_CLOSEST_ULL((u64)(req_min_uV - min_uV) *
+					  diff_duty,
+					  diff_uV);
+
+	if (max_uV_duty < min_uV_duty)
+		dutycycle = min_uV_duty - dutycycle;
+	else
+		dutycycle = min_uV_duty + dutycycle;
+
+	pwm_set_relative_duty_cycle(&pstate, dutycycle, duty_unit);
 
-	ret = pwm_config(drvdata->pwm, duty_pulse, pargs.period);
+	ret = pwm_apply_state(drvdata->pwm, &pstate);
 	if (ret) {
 		dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret);
 		return ret;
 	}
 
-	ret = pwm_enable(drvdata->pwm);
-	if (ret) {
-		dev_err(&rdev->dev, "Failed to enable PWM: %d\n", ret);
-		return ret;
-	}
-	drvdata->volt_uV = min_uV;
+	if ((ramp_delay == 0) || !pwm_regulator_is_enabled(rdev))
+		return 0;
 
-	/* Delay required by PWM regulator to settle to the new voltage */
-	usleep_range(ramp_delay, ramp_delay + 1000);
+	/* Ramp delay is in uV/uS. Adjust to uS and delay */
+	ramp_delay = DIV_ROUND_UP(abs(req_min_uV - old_uV), ramp_delay);
+	usleep_range(ramp_delay, ramp_delay + DIV_ROUND_UP(ramp_delay, 10));
 
 	return 0;
 }
@@ -226,6 +297,7 @@ static int pwm_regulator_init_table(struct platform_device *pdev,
 		return ret;
 	}
 
+	drvdata->state			= -EINVAL;
 	drvdata->duty_cycle_table	= duty_cycle_table;
 	memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops,
 	       sizeof(drvdata->ops));
@@ -238,11 +310,28 @@ static int pwm_regulator_init_table(struct platform_device *pdev,
 static int pwm_regulator_init_continuous(struct platform_device *pdev,
 					 struct pwm_regulator_data *drvdata)
 {
+	u32 dutycycle_range[2] = { 0, 100 };
+	u32 dutycycle_unit = 100;
+
 	memcpy(&drvdata->ops, &pwm_regulator_voltage_continuous_ops,
 	       sizeof(drvdata->ops));
 	drvdata->desc.ops = &drvdata->ops;
 	drvdata->desc.continuous_voltage_range = true;
 
+	of_property_read_u32_array(pdev->dev.of_node,
+				   "pwm-dutycycle-range",
+				   dutycycle_range, 2);
+	of_property_read_u32(pdev->dev.of_node, "pwm-dutycycle-unit",
+			     &dutycycle_unit);
+
+	if (dutycycle_range[0] > dutycycle_unit ||
+	    dutycycle_range[1] > dutycycle_unit)
+		return -EINVAL;
+
+	drvdata->continuous.dutycycle_unit = dutycycle_unit;
+	drvdata->continuous.min_uV_dutycycle = dutycycle_range[0];
+	drvdata->continuous.max_uV_dutycycle = dutycycle_range[1];
+
 	return 0;
 }
 
@@ -253,6 +342,7 @@ static int pwm_regulator_probe(struct platform_device *pdev)
 	struct regulator_dev *regulator;
 	struct regulator_config config = { };
 	struct device_node *np = pdev->dev.of_node;
+	enum gpiod_flags gpio_flags;
 	int ret;
 
 	if (!np) {
@@ -290,11 +380,21 @@ static int pwm_regulator_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	/*
-	 * FIXME: pwm_apply_args() should be removed when switching to the
-	 * atomic PWM API.
-	 */
-	pwm_apply_args(drvdata->pwm);
+	if (init_data->constraints.boot_on || init_data->constraints.always_on)
+		gpio_flags = GPIOD_OUT_HIGH;
+	else
+		gpio_flags = GPIOD_OUT_LOW;
+	drvdata->enb_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
+						    gpio_flags);
+	if (IS_ERR(drvdata->enb_gpio)) {
+		ret = PTR_ERR(drvdata->enb_gpio);
+		dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n", ret);
+		return ret;
+	}
+
+	ret = pwm_adjust_config(drvdata->pwm);
+	if (ret)
+		return ret;
 
 	regulator = devm_regulator_register(&pdev->dev,
 					    &drvdata->desc, &config);
