git.sur5r.net Git - u-boot/blob - 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 #include <linux/libfdt.h>
  16 #include <fdt_support.h>
  17 #include <fdtdec.h>
  18
  19 DECLARE_GLOBAL_DATA_PTR;
  20
  21 struct 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
  43 static 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
  50 static 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
  60 static 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
  67 static 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
  93 static int pwm_regulator_ofdata_to_platdata(struct udevice *dev)
  94 {
  95         struct pwm_regulator_info *priv = dev_get_priv(dev);
  96         struct fdtdec_phandle_args args;
  97         const void *blob = gd->fdt_blob;
  98         int node = dev_of_offset(dev);
  99         int ret;
 100
 101         ret = fdtdec_parse_phandle_with_args(blob, node, "pwms", "#pwm-cells",
 102                                              0, 0, &args);
 103         if (ret) {
 104                 debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
 105                 return ret;
 106         }
 107
 108         priv->period_ns = args.args[1];
 109         priv->polarity = args.args[2];
 110
 111         priv->init_voltage = fdtdec_get_int(blob, node,
 112                         "regulator-init-microvolt", -1);
 113         if (priv->init_voltage < 0) {
 114                 printf("Cannot find regulator pwm init_voltage\n");
 115                 return -EINVAL;
 116         }
 117
 118         ret = uclass_get_device_by_of_offset(UCLASS_PWM, args.node, &priv->pwm);
 119         if (ret) {
 120                 debug("%s: Cannot get PWM: ret=%d\n", __func__, ret);
 121                 return ret;
 122         }
 123
 124         return 0;
 125 }
 126
 127 static int pwm_regulator_probe(struct udevice *dev)
 128 {
 129         struct pwm_regulator_info *priv = dev_get_priv(dev);
 130         struct dm_regulator_uclass_platdata *uc_pdata;
 131
 132         uc_pdata = dev_get_uclass_platdata(dev);
 133
 134         uc_pdata->type = REGULATOR_TYPE_BUCK;
 135         uc_pdata->mode_count = 0;
 136         priv->max_voltage = uc_pdata->max_uV;
 137         priv->min_voltage = uc_pdata->min_uV;
 138
 139         if (priv->init_voltage)
 140                 pwm_regulator_set_voltage(dev, priv->init_voltage);
 141
 142         return 0;
 143 }
 144
 145 static const struct dm_regulator_ops pwm_regulator_ops = {
 146         .get_value  = pwm_regulator_get_voltage,
 147         .set_value  = pwm_regulator_set_voltage,
 148         .set_enable = pwm_regulator_enable,
 149 };
 150
 151 static const struct udevice_id pwm_regulator_ids[] = {
 152         { .compatible = "pwm-regulator" },
 153         { }
 154 };
 155
 156 U_BOOT_DRIVER(pwm_regulator) = {
 157         .name = "pwm_regulator",
 158         .id = UCLASS_REGULATOR,
 159         .ops = &pwm_regulator_ops,
 160         .probe = pwm_regulator_probe,
 161         .of_match = pwm_regulator_ids,
 162         .ofdata_to_platdata     = pwm_regulator_ofdata_to_platdata,
 163         .priv_auto_alloc_size   = sizeof(struct pwm_regulator_info),
 164 };