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412 lines
11 KiB
412 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Regulator driver for PWM Regulators |
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* |
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* Copyright (C) 2014 - STMicroelectronics Inc. |
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* |
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* Author: Lee Jones <[email protected]> |
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*/ |
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/err.h> |
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#include <linux/regulator/driver.h> |
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#include <linux/regulator/machine.h> |
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#include <linux/regulator/of_regulator.h> |
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#include <linux/of.h> |
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#include <linux/of_device.h> |
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#include <linux/pwm.h> |
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#include <linux/gpio/consumer.h> |
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struct pwm_continuous_reg_data { |
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unsigned int min_uV_dutycycle; |
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unsigned int max_uV_dutycycle; |
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unsigned int dutycycle_unit; |
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}; |
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struct pwm_regulator_data { |
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/* Shared */ |
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struct pwm_device *pwm; |
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/* Voltage table */ |
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struct pwm_voltages *duty_cycle_table; |
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/* Continuous mode info */ |
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struct pwm_continuous_reg_data continuous; |
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/* regulator descriptor */ |
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struct regulator_desc desc; |
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int state; |
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/* Enable GPIO */ |
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struct gpio_desc *enb_gpio; |
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}; |
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struct pwm_voltages { |
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unsigned int uV; |
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unsigned int dutycycle; |
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}; |
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/* |
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* Voltage table call-backs |
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*/ |
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static void pwm_regulator_init_state(struct regulator_dev *rdev) |
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{ |
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struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
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struct pwm_state pwm_state; |
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unsigned int dutycycle; |
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int i; |
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pwm_get_state(drvdata->pwm, &pwm_state); |
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dutycycle = pwm_get_relative_duty_cycle(&pwm_state, 100); |
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for (i = 0; i < rdev->desc->n_voltages; i++) { |
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if (dutycycle == drvdata->duty_cycle_table[i].dutycycle) { |
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drvdata->state = i; |
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return; |
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} |
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} |
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} |
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static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev) |
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{ |
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struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
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if (drvdata->state < 0) |
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pwm_regulator_init_state(rdev); |
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return drvdata->state; |
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} |
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static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev, |
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unsigned selector) |
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{ |
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struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
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struct pwm_state pstate; |
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int ret; |
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pwm_init_state(drvdata->pwm, &pstate); |
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pwm_set_relative_duty_cycle(&pstate, |
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drvdata->duty_cycle_table[selector].dutycycle, 100); |
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ret = pwm_apply_state(drvdata->pwm, &pstate); |
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if (ret) { |
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dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); |
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return ret; |
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} |
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drvdata->state = selector; |
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return 0; |
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} |
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static int pwm_regulator_list_voltage(struct regulator_dev *rdev, |
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unsigned selector) |
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{ |
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struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
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if (selector >= rdev->desc->n_voltages) |
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return -EINVAL; |
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return drvdata->duty_cycle_table[selector].uV; |
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} |
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static int pwm_regulator_enable(struct regulator_dev *dev) |
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{ |
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struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); |
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gpiod_set_value_cansleep(drvdata->enb_gpio, 1); |
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return pwm_enable(drvdata->pwm); |
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} |
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static int pwm_regulator_disable(struct regulator_dev *dev) |
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{ |
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struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); |
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pwm_disable(drvdata->pwm); |
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gpiod_set_value_cansleep(drvdata->enb_gpio, 0); |
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return 0; |
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} |
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static int pwm_regulator_is_enabled(struct regulator_dev *dev) |
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{ |
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struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); |
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if (drvdata->enb_gpio && !gpiod_get_value_cansleep(drvdata->enb_gpio)) |
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return false; |
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return pwm_is_enabled(drvdata->pwm); |
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} |
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static int pwm_regulator_get_voltage(struct regulator_dev *rdev) |
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{ |
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struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
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unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle; |
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unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle; |
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unsigned int duty_unit = drvdata->continuous.dutycycle_unit; |
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int min_uV = rdev->constraints->min_uV; |
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int max_uV = rdev->constraints->max_uV; |
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int diff_uV = max_uV - min_uV; |
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struct pwm_state pstate; |
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unsigned int diff_duty; |
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unsigned int voltage; |
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pwm_get_state(drvdata->pwm, &pstate); |
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voltage = pwm_get_relative_duty_cycle(&pstate, duty_unit); |
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/* |
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* The dutycycle for min_uV might be greater than the one for max_uV. |
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* This is happening when the user needs an inversed polarity, but the |
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* PWM device does not support inversing it in hardware. |
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*/ |
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if (max_uV_duty < min_uV_duty) { |
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voltage = min_uV_duty - voltage; |
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diff_duty = min_uV_duty - max_uV_duty; |
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} else { |
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voltage = voltage - min_uV_duty; |
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diff_duty = max_uV_duty - min_uV_duty; |
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} |
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voltage = DIV_ROUND_CLOSEST_ULL((u64)voltage * diff_uV, diff_duty); |
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return voltage + min_uV; |
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} |
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static int pwm_regulator_set_voltage(struct regulator_dev *rdev, |
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int req_min_uV, int req_max_uV, |
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unsigned int *selector) |
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{ |
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struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); |
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unsigned int min_uV_duty = drvdata->continuous.min_uV_dutycycle; |
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unsigned int max_uV_duty = drvdata->continuous.max_uV_dutycycle; |
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unsigned int duty_unit = drvdata->continuous.dutycycle_unit; |
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int min_uV = rdev->constraints->min_uV; |
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int max_uV = rdev->constraints->max_uV; |
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int diff_uV = max_uV - min_uV; |
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struct pwm_state pstate; |
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unsigned int diff_duty; |
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unsigned int dutycycle; |
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int ret; |
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pwm_init_state(drvdata->pwm, &pstate); |
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/* |
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* The dutycycle for min_uV might be greater than the one for max_uV. |
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* This is happening when the user needs an inversed polarity, but the |
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* PWM device does not support inversing it in hardware. |
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*/ |
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if (max_uV_duty < min_uV_duty) |
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diff_duty = min_uV_duty - max_uV_duty; |
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else |
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diff_duty = max_uV_duty - min_uV_duty; |
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dutycycle = DIV_ROUND_CLOSEST_ULL((u64)(req_min_uV - min_uV) * |
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diff_duty, |
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diff_uV); |
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if (max_uV_duty < min_uV_duty) |
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dutycycle = min_uV_duty - dutycycle; |
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else |
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dutycycle = min_uV_duty + dutycycle; |
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pwm_set_relative_duty_cycle(&pstate, dutycycle, duty_unit); |
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ret = pwm_apply_state(drvdata->pwm, &pstate); |
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if (ret) { |
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dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); |
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return ret; |
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} |
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return 0; |
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} |
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static const struct regulator_ops pwm_regulator_voltage_table_ops = { |
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.set_voltage_sel = pwm_regulator_set_voltage_sel, |
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.get_voltage_sel = pwm_regulator_get_voltage_sel, |
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.list_voltage = pwm_regulator_list_voltage, |
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.map_voltage = regulator_map_voltage_iterate, |
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.enable = pwm_regulator_enable, |
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.disable = pwm_regulator_disable, |
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.is_enabled = pwm_regulator_is_enabled, |
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}; |
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static const struct regulator_ops pwm_regulator_voltage_continuous_ops = { |
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.get_voltage = pwm_regulator_get_voltage, |
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.set_voltage = pwm_regulator_set_voltage, |
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.enable = pwm_regulator_enable, |
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.disable = pwm_regulator_disable, |
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.is_enabled = pwm_regulator_is_enabled, |
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}; |
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static const struct regulator_desc pwm_regulator_desc = { |
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.name = "pwm-regulator", |
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.type = REGULATOR_VOLTAGE, |
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.owner = THIS_MODULE, |
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.supply_name = "pwm", |
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}; |
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static int pwm_regulator_init_table(struct platform_device *pdev, |
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struct pwm_regulator_data *drvdata) |
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{ |
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struct device_node *np = pdev->dev.of_node; |
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struct pwm_voltages *duty_cycle_table; |
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unsigned int length = 0; |
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int ret; |
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of_find_property(np, "voltage-table", &length); |
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if ((length < sizeof(*duty_cycle_table)) || |
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(length % sizeof(*duty_cycle_table))) { |
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dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n", |
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length); |
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return -EINVAL; |
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} |
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duty_cycle_table = devm_kzalloc(&pdev->dev, length, GFP_KERNEL); |
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if (!duty_cycle_table) |
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return -ENOMEM; |
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ret = of_property_read_u32_array(np, "voltage-table", |
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(u32 *)duty_cycle_table, |
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length / sizeof(u32)); |
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if (ret) { |
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dev_err(&pdev->dev, "Failed to read voltage-table: %d\n", ret); |
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return ret; |
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} |
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drvdata->state = -ENOTRECOVERABLE; |
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drvdata->duty_cycle_table = duty_cycle_table; |
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drvdata->desc.ops = &pwm_regulator_voltage_table_ops; |
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drvdata->desc.n_voltages = length / sizeof(*duty_cycle_table); |
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return 0; |
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} |
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static int pwm_regulator_init_continuous(struct platform_device *pdev, |
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struct pwm_regulator_data *drvdata) |
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{ |
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u32 dutycycle_range[2] = { 0, 100 }; |
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u32 dutycycle_unit = 100; |
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drvdata->desc.ops = &pwm_regulator_voltage_continuous_ops; |
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drvdata->desc.continuous_voltage_range = true; |
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of_property_read_u32_array(pdev->dev.of_node, |
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"pwm-dutycycle-range", |
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dutycycle_range, 2); |
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of_property_read_u32(pdev->dev.of_node, "pwm-dutycycle-unit", |
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&dutycycle_unit); |
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if (dutycycle_range[0] > dutycycle_unit || |
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dutycycle_range[1] > dutycycle_unit) |
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return -EINVAL; |
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drvdata->continuous.dutycycle_unit = dutycycle_unit; |
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drvdata->continuous.min_uV_dutycycle = dutycycle_range[0]; |
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drvdata->continuous.max_uV_dutycycle = dutycycle_range[1]; |
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return 0; |
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} |
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static int pwm_regulator_probe(struct platform_device *pdev) |
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{ |
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const struct regulator_init_data *init_data; |
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struct pwm_regulator_data *drvdata; |
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struct regulator_dev *regulator; |
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struct regulator_config config = { }; |
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struct device_node *np = pdev->dev.of_node; |
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enum gpiod_flags gpio_flags; |
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int ret; |
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if (!np) { |
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dev_err(&pdev->dev, "Device Tree node missing\n"); |
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return -EINVAL; |
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} |
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drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); |
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if (!drvdata) |
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return -ENOMEM; |
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memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(drvdata->desc)); |
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if (of_find_property(np, "voltage-table", NULL)) |
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ret = pwm_regulator_init_table(pdev, drvdata); |
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else |
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ret = pwm_regulator_init_continuous(pdev, drvdata); |
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if (ret) |
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return ret; |
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init_data = of_get_regulator_init_data(&pdev->dev, np, |
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&drvdata->desc); |
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if (!init_data) |
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return -ENOMEM; |
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config.of_node = np; |
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config.dev = &pdev->dev; |
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config.driver_data = drvdata; |
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config.init_data = init_data; |
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drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); |
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if (IS_ERR(drvdata->pwm)) { |
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ret = PTR_ERR(drvdata->pwm); |
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if (ret == -EPROBE_DEFER) |
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dev_dbg(&pdev->dev, |
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"Failed to get PWM, deferring probe\n"); |
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else |
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dev_err(&pdev->dev, "Failed to get PWM: %d\n", ret); |
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return ret; |
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} |
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if (init_data->constraints.boot_on || init_data->constraints.always_on) |
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gpio_flags = GPIOD_OUT_HIGH; |
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else |
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gpio_flags = GPIOD_OUT_LOW; |
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drvdata->enb_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", |
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gpio_flags); |
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if (IS_ERR(drvdata->enb_gpio)) { |
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ret = PTR_ERR(drvdata->enb_gpio); |
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dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n", ret); |
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return ret; |
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} |
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ret = pwm_adjust_config(drvdata->pwm); |
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if (ret) |
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return ret; |
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regulator = devm_regulator_register(&pdev->dev, |
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&drvdata->desc, &config); |
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if (IS_ERR(regulator)) { |
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ret = PTR_ERR(regulator); |
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dev_err(&pdev->dev, "Failed to register regulator %s: %d\n", |
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drvdata->desc.name, ret); |
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return ret; |
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} |
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return 0; |
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} |
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static const struct of_device_id __maybe_unused pwm_of_match[] = { |
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{ .compatible = "pwm-regulator" }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(of, pwm_of_match); |
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static struct platform_driver pwm_regulator_driver = { |
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.driver = { |
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.name = "pwm-regulator", |
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.of_match_table = of_match_ptr(pwm_of_match), |
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}, |
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.probe = pwm_regulator_probe, |
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}; |
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module_platform_driver(pwm_regulator_driver); |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("Lee Jones <[email protected]>"); |
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MODULE_DESCRIPTION("PWM Regulator Driver"); |
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MODULE_ALIAS("platform:pwm-regulator");
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