1 /* 2 * Copyright (C) 2016 Rockchip Electronics Co., Ltd 3 * 4 * Based on kernel drivers/regulator/pwm-regulator.c 5 * Copyright (C) 2014 - STMicroelectronics Inc. 6 * Author: Lee Jones <lee.jones@linaro.org> 7 * 8 * SPDX-License-Identifier: GPL-2.0+ 9 */ 10 11 #include <common.h> 12 #include <dm.h> 13 #include <errno.h> 14 #include <pwm.h> 15 #include <power/regulator.h> 16 #include <libfdt.h> 17 #include <fdt_support.h> 18 #include <fdtdec.h> 19 20 DECLARE_GLOBAL_DATA_PTR; 21 22 struct pwm_regulator_info { 23 /* pwm id corresponding to the PWM driver */ 24 int pwm_id; 25 /* the period of one PWM cycle */ 26 int period_ns; 27 /* 28 * the polarity of one PWM 29 * 0: normal polarity 30 * 1: inverted polarity 31 */ 32 bool polarity; 33 struct udevice *pwm; 34 /* initialize voltage of regulator */ 35 int init_voltage; 36 /* the maximum voltage of regulator */ 37 int max_voltage; 38 /* the minimum voltage of regulator */ 39 int min_voltage; 40 /* the current voltage of regulator */ 41 int volt_uV; 42 }; 43 44 static int pwm_regulator_enable(struct udevice *dev, bool enable) 45 { 46 struct pwm_regulator_info *priv = dev_get_priv(dev); 47 48 return pwm_set_enable(priv->pwm, priv->pwm_id, enable); 49 } 50 51 static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV) 52 { 53 struct pwm_regulator_info *priv = dev_get_priv(dev); 54 int min_uV = priv->min_voltage; 55 int max_uV = priv->max_voltage; 56 int diff = max_uV - min_uV; 57 58 return ((req_uV * 100) - (min_uV * 100)) / diff; 59 } 60 61 static int pwm_regulator_get_voltage(struct udevice *dev) 62 { 63 struct pwm_regulator_info *priv = dev_get_priv(dev); 64 65 return priv->volt_uV; 66 } 67 68 static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt) 69 { 70 struct pwm_regulator_info *priv = dev_get_priv(dev); 71 int duty_cycle; 72 int ret = 0; 73 74 duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt); 75 76 ret = pwm_set_invert(priv->pwm, priv->pwm_id, priv->polarity); 77 if (ret) { 78 dev_err(dev, "Failed to init PWM\n"); 79 return ret; 80 } 81 82 ret = pwm_set_config(priv->pwm, priv->pwm_id, 83 (priv->period_ns / 100) * duty_cycle, priv->period_ns); 84 if (ret) { 85 dev_err(dev, "Failed to configure PWM\n"); 86 return ret; 87 } 88 89 ret = pwm_set_enable(priv->pwm, priv->pwm_id, true); 90 if (ret) { 91 dev_err(dev, "Failed to enable PWM\n"); 92 return ret; 93 } 94 priv->volt_uV = uvolt; 95 return ret; 96 } 97 98 static int pwm_regulator_ofdata_to_platdata(struct udevice *dev) 99 { 100 struct pwm_regulator_info *priv = dev_get_priv(dev); 101 struct fdtdec_phandle_args args; 102 const void *blob = gd->fdt_blob; 103 int node = dev_of_offset(dev); 104 int ret; 105 106 ret = fdtdec_parse_phandle_with_args(blob, node, "pwms", "#pwm-cells", 107 0, 0, &args); 108 if (ret) { 109 debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret); 110 return ret; 111 } 112 113 priv->period_ns = args.args[1]; 114 priv->polarity = args.args[2]; 115 116 priv->init_voltage = fdtdec_get_int(blob, node, 117 "regulator-init-microvolt", -1); 118 if (priv->init_voltage < 0) { 119 printf("Cannot find regulator pwm init_voltage\n"); 120 return -EINVAL; 121 } 122 123 ret = uclass_get_device_by_of_offset(UCLASS_PWM, args.node, &priv->pwm); 124 if (ret) { 125 debug("%s: Cannot get PWM: ret=%d\n", __func__, ret); 126 return ret; 127 } 128 129 return 0; 130 } 131 132 static int pwm_regulator_probe(struct udevice *dev) 133 { 134 struct pwm_regulator_info *priv = dev_get_priv(dev); 135 struct dm_regulator_uclass_platdata *uc_pdata; 136 137 uc_pdata = dev_get_uclass_platdata(dev); 138 139 uc_pdata->type = REGULATOR_TYPE_BUCK; 140 uc_pdata->mode_count = 0; 141 priv->max_voltage = uc_pdata->max_uV; 142 priv->min_voltage = uc_pdata->min_uV; 143 144 if (priv->init_voltage) 145 pwm_regulator_set_voltage(dev, priv->init_voltage); 146 147 pwm_regulator_enable(dev, 1); 148 149 return 0; 150 } 151 152 static const struct dm_regulator_ops pwm_regulator_ops = { 153 .get_value = pwm_regulator_get_voltage, 154 .set_value = pwm_regulator_set_voltage, 155 .set_enable = pwm_regulator_enable, 156 }; 157 158 static const struct udevice_id pwm_regulator_ids[] = { 159 { .compatible = "pwm-regulator" }, 160 { } 161 }; 162 163 U_BOOT_DRIVER(pwm_regulator) = { 164 .name = "pwm_regulator", 165 .id = UCLASS_REGULATOR, 166 .ops = &pwm_regulator_ops, 167 .probe = pwm_regulator_probe, 168 .of_match = pwm_regulator_ids, 169 .ofdata_to_platdata = pwm_regulator_ofdata_to_platdata, 170 .priv_auto_alloc_size = sizeof(struct pwm_regulator_info), 171 }; 172