1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * Copyright (C) 2016 Rockchip Electronics Co., Ltd 4 * 5 * Based on kernel drivers/regulator/pwm-regulator.c 6 * Copyright (C) 2014 - STMicroelectronics Inc. 7 * Author: Lee Jones <lee.jones@linaro.org> 8 */ 9 10#include <common.h> 11#include <dm.h> 12#include <errno.h> 13#include <log.h> 14#include <pwm.h> 15#include <asm/global_data.h> 16#include <dm/device_compat.h> 17#include <power/regulator.h> 18 19DECLARE_GLOBAL_DATA_PTR; 20 21struct pwm_regulator_info { 22 /* pwm id corresponding to the PWM driver */ 23 int pwm_id; 24 /* the period of one PWM cycle */ 25 int period_ns; 26 /* 27 * the polarity of one PWM 28 * 0: normal polarity 29 * 1: inverted polarity 30 */ 31 bool polarity; 32 struct udevice *pwm; 33 /* initialize voltage of regulator */ 34 int init_voltage; 35 /* the maximum voltage of regulator */ 36 int max_voltage; 37 /* the minimum voltage of regulator */ 38 int min_voltage; 39 /* the current voltage of regulator */ 40 int volt_uV; 41}; 42 43static int pwm_regulator_enable(struct udevice *dev, bool enable) 44{ 45 struct pwm_regulator_info *priv = dev_get_priv(dev); 46 47 return pwm_set_enable(priv->pwm, priv->pwm_id, enable); 48} 49 50static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV) 51{ 52 struct pwm_regulator_info *priv = dev_get_priv(dev); 53 int min_uV = priv->min_voltage; 54 int max_uV = priv->max_voltage; 55 int diff = max_uV - min_uV; 56 57 return ((req_uV * 100) - (min_uV * 100)) / diff; 58} 59 60static int pwm_regulator_get_voltage(struct udevice *dev) 61{ 62 struct pwm_regulator_info *priv = dev_get_priv(dev); 63 64 return priv->volt_uV; 65} 66 67static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt) 68{ 69 struct pwm_regulator_info *priv = dev_get_priv(dev); 70 int duty_cycle; 71 int ret = 0; 72 73 duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt); 74 75 ret = pwm_set_invert(priv->pwm, priv->pwm_id, priv->polarity); 76 if (ret) { 77 dev_err(dev, "Failed to init PWM\n"); 78 return ret; 79 } 80 81 ret = pwm_set_config(priv->pwm, priv->pwm_id, 82 priv->period_ns, (priv->period_ns / 100) * duty_cycle); 83 if (ret) { 84 dev_err(dev, "Failed to configure PWM\n"); 85 return ret; 86 } 87 88 priv->volt_uV = uvolt; 89 90 return ret; 91} 92 93static int pwm_regulator_of_to_plat(struct udevice *dev) 94{ 95 struct pwm_regulator_info *priv = dev_get_priv(dev); 96 struct ofnode_phandle_args args; 97 int ret; 98 99 ret = dev_read_phandle_with_args(dev, "pwms", "#pwm-cells", 0, 0, &args); 100 if (ret) { 101 debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret); 102 return ret; 103 } 104 105 priv->period_ns = args.args[1]; 106 priv->polarity = args.args[2]; 107 108 priv->init_voltage = dev_read_u32_default(dev, "regulator-init-microvolt", -1); 109 if (priv->init_voltage < 0) { 110 printf("Cannot find regulator pwm init_voltage\n"); 111 return -EINVAL; 112 } 113 114 ret = uclass_get_device_by_ofnode(UCLASS_PWM, args.node, &priv->pwm); 115 if (ret) { 116 debug("%s: Cannot get PWM: ret=%d\n", __func__, ret); 117 return ret; 118 } 119 120 return 0; 121} 122 123static int pwm_regulator_probe(struct udevice *dev) 124{ 125 struct pwm_regulator_info *priv = dev_get_priv(dev); 126 struct dm_regulator_uclass_plat *uc_pdata; 127 128 uc_pdata = dev_get_uclass_plat(dev); 129 130 uc_pdata->type = REGULATOR_TYPE_BUCK; 131 uc_pdata->mode_count = 0; 132 priv->max_voltage = uc_pdata->max_uV; 133 priv->min_voltage = uc_pdata->min_uV; 134 135 if (priv->init_voltage) 136 pwm_regulator_set_voltage(dev, priv->init_voltage); 137 138 return 0; 139} 140 141static const struct dm_regulator_ops pwm_regulator_ops = { 142 .get_value = pwm_regulator_get_voltage, 143 .set_value = pwm_regulator_set_voltage, 144 .set_enable = pwm_regulator_enable, 145}; 146 147static const struct udevice_id pwm_regulator_ids[] = { 148 { .compatible = "pwm-regulator" }, 149 { } 150}; 151 152U_BOOT_DRIVER(pwm_regulator) = { 153 .name = "pwm_regulator", 154 .id = UCLASS_REGULATOR, 155 .ops = &pwm_regulator_ops, 156 .probe = pwm_regulator_probe, 157 .of_match = pwm_regulator_ids, 158 .of_to_plat = pwm_regulator_of_to_plat, 159 .priv_auto = sizeof(struct pwm_regulator_info), 160}; 161