| // 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); |
| if (voltage < min(max_uV_duty, min_uV_duty) || |
| voltage > max(max_uV_duty, min_uV_duty)) |
| return -ENOTRECOVERABLE; |
| |
| /* |
| * 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)) { |
| ret = PTR_ERR(drvdata->pwm); |
| dev_err(&pdev->dev, "Failed to get PWM: %d\n", ret); |
| return ret; |
| } |
| |
| 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 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"); |