drivers/power/regulator/pwm_regulator.c

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