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path: root/drivers/regulator/pwm-regulator.c
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Diffstat (limited to 'drivers/regulator/pwm-regulator.c')
-rw-r--r--drivers/regulator/pwm-regulator.c406
1 files changed, 406 insertions, 0 deletions
diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
new file mode 100644
index 000000000..b9eeaff1c
--- /dev/null
+++ b/drivers/regulator/pwm-regulator.c
@@ -0,0 +1,406 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Regulator driver for PWM Regulators
+ *
+ * Copyright (C) 2014 - STMicroelectronics Inc.
+ *
+ * Author: Lee Jones <lee.jones@linaro.org>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#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 */
+ struct pwm_device *pwm;
+
+ /* Voltage table */
+ struct pwm_voltages *duty_cycle_table;
+
+ /* Continuous mode info */
+ struct pwm_continuous_reg_data continuous;
+
+ /* regulator descriptor */
+ struct regulator_desc desc;
+
+ int state;
+
+ /* Enable GPIO */
+ struct gpio_desc *enb_gpio;
+};
+
+struct pwm_voltages {
+ unsigned int uV;
+ unsigned int dutycycle;
+};
+
+/*
+ * 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_state pstate;
+ int ret;
+
+ pwm_init_state(drvdata->pwm, &pstate);
+ pwm_set_relative_duty_cycle(&pstate,
+ drvdata->duty_cycle_table[selector].dutycycle, 100);
+
+ ret = pwm_apply_state(drvdata->pwm, &pstate);
+ if (ret) {
+ dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret);
+ return ret;
+ }
+
+ drvdata->state = selector;
+
+ return 0;
+}
+
+static int pwm_regulator_list_voltage(struct regulator_dev *rdev,
+ unsigned selector)
+{
+ struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
+
+ if (selector >= rdev->desc->n_voltages)
+ return -EINVAL;
+
+ return drvdata->duty_cycle_table[selector].uV;
+}
+
+static int pwm_regulator_enable(struct regulator_dev *dev)
+{
+ struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+
+ gpiod_set_value_cansleep(drvdata->enb_gpio, 1);
+
+ return pwm_enable(drvdata->pwm);
+}
+
+static int pwm_regulator_disable(struct regulator_dev *dev)
+{
+ struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+
+ pwm_disable(drvdata->pwm);
+
+ 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 voltage + min_uV;
+}
+
+static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
+ 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;
+ 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 dutycycle;
+ int ret;
+
+ pwm_init_state(drvdata->pwm, &pstate);
+
+ /*
+ * 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)
+ 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_apply_state(drvdata->pwm, &pstate);
+ if (ret) {
+ dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct regulator_ops pwm_regulator_voltage_table_ops = {
+ .set_voltage_sel = pwm_regulator_set_voltage_sel,
+ .get_voltage_sel = pwm_regulator_get_voltage_sel,
+ .list_voltage = pwm_regulator_list_voltage,
+ .map_voltage = regulator_map_voltage_iterate,
+ .enable = pwm_regulator_enable,
+ .disable = pwm_regulator_disable,
+ .is_enabled = pwm_regulator_is_enabled,
+};
+
+static const struct regulator_ops pwm_regulator_voltage_continuous_ops = {
+ .get_voltage = pwm_regulator_get_voltage,
+ .set_voltage = pwm_regulator_set_voltage,
+ .enable = pwm_regulator_enable,
+ .disable = pwm_regulator_disable,
+ .is_enabled = pwm_regulator_is_enabled,
+};
+
+static const struct regulator_desc pwm_regulator_desc = {
+ .name = "pwm-regulator",
+ .type = REGULATOR_VOLTAGE,
+ .owner = THIS_MODULE,
+ .supply_name = "pwm",
+};
+
+static int pwm_regulator_init_table(struct platform_device *pdev,
+ struct pwm_regulator_data *drvdata)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct pwm_voltages *duty_cycle_table;
+ unsigned int length = 0;
+ int ret;
+
+ of_find_property(np, "voltage-table", &length);
+
+ if ((length < sizeof(*duty_cycle_table)) ||
+ (length % sizeof(*duty_cycle_table))) {
+ dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n",
+ length);
+ return -EINVAL;
+ }
+
+ duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL);
+ if (!duty_cycle_table)
+ return -ENOMEM;
+
+ ret = of_property_read_u32_array(np, "voltage-table",
+ (u32 *)duty_cycle_table,
+ length / sizeof(u32));
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to read voltage-table: %d\n", ret);
+ return ret;
+ }
+
+ drvdata->state = -ENOTRECOVERABLE;
+ drvdata->duty_cycle_table = duty_cycle_table;
+ drvdata->desc.ops = &pwm_regulator_voltage_table_ops;
+ drvdata->desc.n_voltages = length / sizeof(*duty_cycle_table);
+
+ return 0;
+}
+
+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;
+
+ drvdata->desc.ops = &pwm_regulator_voltage_continuous_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;
+}
+
+static int pwm_regulator_probe(struct platform_device *pdev)
+{
+ const struct regulator_init_data *init_data;
+ struct pwm_regulator_data *drvdata;
+ 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) {
+ dev_err(&pdev->dev, "Device Tree node missing\n");
+ return -EINVAL;
+ }
+
+ drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc));
+
+ if (of_find_property(np, "voltage-table", NULL))
+ ret = pwm_regulator_init_table(pdev, drvdata);
+ else
+ ret = pwm_regulator_init_continuous(pdev, drvdata);
+ if (ret)
+ return ret;
+
+ init_data = of_get_regulator_init_data(&pdev->dev, np,
+ &drvdata->desc);
+ if (!init_data)
+ return -ENOMEM;
+
+ config.of_node = np;
+ config.dev = &pdev->dev;
+ config.driver_data = drvdata;
+ config.init_data = init_data;
+
+ drvdata->pwm = devm_pwm_get(&pdev->dev, NULL);
+ if (IS_ERR(drvdata->pwm))
+ return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->pwm),
+ "Failed to get PWM\n");
+
+ 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);
+ if (IS_ERR(regulator)) {
+ ret = PTR_ERR(regulator);
+ dev_err(&pdev->dev, "Failed to register regulator %s: %d\n",
+ drvdata->desc.name, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id __maybe_unused pwm_of_match[] = {
+ { .compatible = "pwm-regulator" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, pwm_of_match);
+
+static struct platform_driver pwm_regulator_driver = {
+ .driver = {
+ .name = "pwm-regulator",
+ .of_match_table = of_match_ptr(pwm_of_match),
+ },
+ .probe = pwm_regulator_probe,
+};
+
+module_platform_driver(pwm_regulator_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>");
+MODULE_DESCRIPTION("PWM Regulator Driver");
+MODULE_ALIAS("platform:pwm-regulator");