drivers/regulator/max20411-regulator.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2021, The Linux Foundation. All rights reserved.
   4  * Copyright (c) 2022, Linaro Ltd.
   5  */
   6
   7 #include <linux/bitfield.h>
   8 #include <linux/gpio/consumer.h>
   9 #include <linux/i2c.h>
  10 #include <linux/module.h>
  11 #include <linux/of_platform.h>
  12 #include <linux/regmap.h>
  13 #include <linux/regulator/driver.h>
  14 #include <linux/regulator/machine.h>
  15 #include <linux/regulator/of_regulator.h>
  16
  17 #define MAX20411_UV_STEP                6250
  18 #define MAX20411_BASE_UV                243750
  19 #define MAX20411_MIN_SEL                41 /* 0.5V */
  20 #define MAX20411_MAX_SEL                165 /* 1.275V */
  21 #define MAX20411_VID_OFFSET             0x7
  22 #define MAX20411_VID_MASK               0xff
  23 #define MAX20411_SLEW_OFFSET            0x6
  24 #define MAX20411_SLEW_DVS_MASK          0xc
  25 #define MAX20411_SLEW_SR_MASK           0x3
  26
  27 struct max20411 {
  28         struct device *dev;
  29         struct device_node *of_node;
  30         struct regulator_desc desc;
  31         struct regulator_dev *rdev;
  32         struct regmap *regmap;
  33 };
  34
  35 static const unsigned int max20411_slew_rates[] = { 13100, 6600, 3300, 1600 };
  36
  37 static int max20411_enable_time(struct regulator_dev *rdev)
  38 {
  39         int voltage, rate, ret;
  40         unsigned int val;
  41
  42         /* get voltage */
  43         ret = regmap_read(rdev->regmap, rdev->desc->vsel_reg, &val);
  44         if (ret)
  45                 return ret;
  46
  47         val &= rdev->desc->vsel_mask;
  48         voltage = regulator_list_voltage_linear(rdev, val);
  49
  50         /* get rate */
  51         ret = regmap_read(rdev->regmap, MAX20411_SLEW_OFFSET, &val);
  52         if (ret)
  53                 return ret;
  54
  55         val = FIELD_GET(MAX20411_SLEW_SR_MASK, val);
  56         rate = max20411_slew_rates[val];
  57
  58         return DIV_ROUND_UP(voltage, rate);
  59 }
  60
  61 static const struct regmap_config max20411_regmap_config = {
  62         .reg_bits               = 8,
  63         .val_bits               = 8,
  64         .max_register           = 0xe,
  65 };
  66
  67 static const struct regulator_ops max20411_ops = {
  68         .get_voltage_sel        = regulator_get_voltage_sel_regmap,
  69         .set_voltage_sel        = regulator_set_voltage_sel_regmap,
  70         .list_voltage           = regulator_list_voltage_linear,
  71         .enable_time            = max20411_enable_time,
  72 };
  73
  74 static const struct regulator_desc max20411_desc = {
  75         .ops = &max20411_ops,
  76         .owner = THIS_MODULE,
  77         .type = REGULATOR_VOLTAGE,
  78         .supply_name = "vin",
  79         .name = "max20411",
  80
  81         /*
  82          * voltage = 0.24375V + selector * 6.25mV
  83          * with valid selector between 41 to 165 (0.5V to 1.275V)
  84          */
  85         .min_uV = MAX20411_BASE_UV,
  86         .uV_step = MAX20411_UV_STEP,
  87         .linear_min_sel = MAX20411_MIN_SEL,
  88         .n_voltages = MAX20411_MAX_SEL + 1,
  89
  90         .vsel_reg = MAX20411_VID_OFFSET,
  91         .vsel_mask = MAX20411_VID_MASK,
  92
  93         .ramp_reg = MAX20411_SLEW_OFFSET,
  94         .ramp_mask = MAX20411_SLEW_DVS_MASK,
  95         .ramp_delay_table = max20411_slew_rates,
  96         .n_ramp_values = ARRAY_SIZE(max20411_slew_rates),
  97 };
  98
  99 static int max20411_probe(struct i2c_client *client)
 100 {
 101         struct regulator_init_data *init_data;
 102         struct device *dev = &client->dev;
 103         struct regulator_config cfg = {};
 104         struct max20411 *max20411;
 105
 106         max20411 = devm_kzalloc(dev, sizeof(*max20411), GFP_KERNEL);
 107         if (!max20411)
 108                 return -ENOMEM;
 109
 110         max20411->regmap = devm_regmap_init_i2c(client, &max20411_regmap_config);
 111         if (IS_ERR(max20411->regmap)) {
 112                 dev_err(dev, "Failed to allocate regmap!\n");
 113                 return PTR_ERR(max20411->regmap);
 114         }
 115
 116         max20411->dev = dev;
 117         max20411->of_node = dev->of_node;
 118
 119         max20411->desc = max20411_desc;
 120         init_data = of_get_regulator_init_data(max20411->dev, max20411->of_node, &max20411->desc);
 121         if (!init_data)
 122                 return -ENODATA;
 123
 124         cfg.dev = max20411->dev;
 125         cfg.init_data = init_data;
 126         cfg.of_node = max20411->of_node;
 127         cfg.driver_data = max20411;
 128
 129         cfg.ena_gpiod = gpiod_get(max20411->dev, "enable", GPIOD_ASIS);
 130         if (IS_ERR(cfg.ena_gpiod))
 131                 return dev_err_probe(dev, PTR_ERR(cfg.ena_gpiod),
 132                                      "unable to acquire enable gpio\n");
 133
 134         max20411->rdev = devm_regulator_register(max20411->dev, &max20411->desc, &cfg);
 135         if (IS_ERR(max20411->rdev))
 136                 dev_err(max20411->dev, "Failed to register regulator\n");
 137
 138         return PTR_ERR_OR_ZERO(max20411->rdev);
 139 }
 140
 141 static const struct of_device_id of_max20411_match_tbl[] = {
 142         { .compatible = "maxim,max20411", },
 143         { },
 144 };
 145 MODULE_DEVICE_TABLE(of, of_max20411_match_tbl);
 146
 147 static const struct i2c_device_id max20411_id[] = {
 148         { "max20411" },
 149         { }
 150 };
 151 MODULE_DEVICE_TABLE(i2c, max20411_id);
 152
 153 static struct i2c_driver max20411_i2c_driver = {
 154         .driver = {
 155                 .name = "max20411",
 156                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 157                 .of_match_table = of_max20411_match_tbl,
 158         },
 159         .probe = max20411_probe,
 160         .id_table = max20411_id,
 161 };
 162 module_i2c_driver(max20411_i2c_driver);
 163
 164 MODULE_DESCRIPTION("Maxim MAX20411 High-Efficiency Single Step-Down Converter driver");
 165 MODULE_LICENSE("GPL");