drivers/regulator/rt4801-regulator.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2
   3 #include <linux/gpio/consumer.h>
   4 #include <linux/i2c.h>
   5 #include <linux/kernel.h>
   6 #include <linux/module.h>
   7 #include <linux/of.h>
   8 #include <linux/regmap.h>
   9 #include <linux/regulator/driver.h>
  10
  11 #define RT4801_REG_VOP  0x00
  12 #define RT4801_REG_VON  0x01
  13 #define RT4801_REG_APPS 0x03
  14
  15 #define VOUT_MASK       0x1F
  16
  17 #define MIN_UV          4000000
  18 #define STEP_UV         100000
  19 #define MAX_UV          6000000
  20 #define N_VOLTAGES      ((MAX_UV - MIN_UV) / STEP_UV + 1)
  21
  22 #define DSV_OUT_POS     0
  23 #define DSV_OUT_NEG     1
  24 #define DSV_OUT_MAX     2
  25
  26 #define DSVP_ENABLE     BIT(0)
  27 #define DSVN_ENABLE     BIT(1)
  28 #define DSVALL_ENABLE   (DSVP_ENABLE | DSVN_ENABLE)
  29
  30 struct rt4801_priv {
  31         struct device *dev;
  32         struct gpio_descs *enable_gpios;
  33         unsigned int enable_flag;
  34         unsigned int volt_sel[DSV_OUT_MAX];
  35 };
  36
  37 static int rt4801_set_voltage_sel(struct regulator_dev *rdev, unsigned int selector)
  38 {
  39         struct rt4801_priv *priv = rdev_get_drvdata(rdev);
  40         int id = rdev_get_id(rdev), ret;
  41
  42         if (priv->enable_flag & BIT(id)) {
  43                 ret = regulator_set_voltage_sel_regmap(rdev, selector);
  44                 if (ret)
  45                         return ret;
  46         }
  47
  48         priv->volt_sel[id] = selector;
  49         return 0;
  50 }
  51
  52 static int rt4801_get_voltage_sel(struct regulator_dev *rdev)
  53 {
  54         struct rt4801_priv *priv = rdev_get_drvdata(rdev);
  55         int id = rdev_get_id(rdev);
  56
  57         if (priv->enable_flag & BIT(id))
  58                 return regulator_get_voltage_sel_regmap(rdev);
  59
  60         return priv->volt_sel[id];
  61 }
  62
  63 static int rt4801_enable(struct regulator_dev *rdev)
  64 {
  65         struct rt4801_priv *priv = rdev_get_drvdata(rdev);
  66         struct gpio_descs *gpios = priv->enable_gpios;
  67         int id = rdev_get_id(rdev), ret;
  68
  69         if (gpios->ndescs <= id) {
  70                 dev_warn(&rdev->dev, "no dedicated gpio can control\n");
  71                 goto bypass_gpio;
  72         }
  73
  74         gpiod_set_value(gpios->desc[id], 1);
  75
  76 bypass_gpio:
  77         ret = regmap_write(rdev->regmap, rdev->desc->vsel_reg, priv->volt_sel[id]);
  78         if (ret)
  79                 return ret;
  80
  81         priv->enable_flag |= BIT(id);
  82         return 0;
  83 }
  84
  85 static int rt4801_disable(struct regulator_dev *rdev)
  86 {
  87         struct rt4801_priv *priv = rdev_get_drvdata(rdev);
  88         struct gpio_descs *gpios = priv->enable_gpios;
  89         int id = rdev_get_id(rdev);
  90
  91         if (gpios->ndescs <= id) {
  92                 dev_warn(&rdev->dev, "no dedicated gpio can control\n");
  93                 goto bypass_gpio;
  94         }
  95
  96         gpiod_set_value(gpios->desc[id], 0);
  97
  98 bypass_gpio:
  99         priv->enable_flag &= ~BIT(id);
 100         return 0;
 101 }
 102
 103 static int rt4801_is_enabled(struct regulator_dev *rdev)
 104 {
 105         struct rt4801_priv *priv = rdev_get_drvdata(rdev);
 106         int id = rdev_get_id(rdev);
 107
 108         return !!(priv->enable_flag & BIT(id));
 109 }
 110
 111 static const struct regulator_ops rt4801_regulator_ops = {
 112         .list_voltage = regulator_list_voltage_linear,
 113         .set_voltage_sel = rt4801_set_voltage_sel,
 114         .get_voltage_sel = rt4801_get_voltage_sel,
 115         .enable = rt4801_enable,
 116         .disable = rt4801_disable,
 117         .is_enabled = rt4801_is_enabled,
 118 };
 119
 120 static const struct regulator_desc rt4801_regulator_descs[] = {
 121         {
 122                 .name = "DSVP",
 123                 .ops = &rt4801_regulator_ops,
 124                 .of_match = of_match_ptr("DSVP"),
 125                 .type = REGULATOR_VOLTAGE,
 126                 .id = DSV_OUT_POS,
 127                 .min_uV = MIN_UV,
 128                 .uV_step = STEP_UV,
 129                 .n_voltages = N_VOLTAGES,
 130                 .owner = THIS_MODULE,
 131                 .vsel_reg = RT4801_REG_VOP,
 132                 .vsel_mask = VOUT_MASK,
 133         },
 134         {
 135                 .name = "DSVN",
 136                 .ops = &rt4801_regulator_ops,
 137                 .of_match = of_match_ptr("DSVN"),
 138                 .type = REGULATOR_VOLTAGE,
 139                 .id = DSV_OUT_NEG,
 140                 .min_uV = MIN_UV,
 141                 .uV_step = STEP_UV,
 142                 .n_voltages = N_VOLTAGES,
 143                 .owner = THIS_MODULE,
 144                 .vsel_reg = RT4801_REG_VON,
 145                 .vsel_mask = VOUT_MASK,
 146         },
 147 };
 148
 149 static const struct regmap_config rt4801_regmap_config = {
 150         .reg_bits = 8,
 151         .val_bits = 8,
 152         .max_register = RT4801_REG_APPS,
 153 };
 154
 155 static int rt4801_probe(struct i2c_client *i2c)
 156 {
 157         struct rt4801_priv *priv;
 158         struct regmap *regmap;
 159         int i;
 160
 161         priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
 162         if (!priv)
 163                 return -ENOMEM;
 164
 165         priv->dev = &i2c->dev;
 166         /* bootloader will on, driver only reconfigure enable to all output high */
 167         priv->enable_flag = DSVALL_ENABLE;
 168
 169         regmap = devm_regmap_init_i2c(i2c, &rt4801_regmap_config);
 170         if (IS_ERR(regmap)) {
 171                 dev_err(&i2c->dev, "Failed to init regmap\n");
 172                 return PTR_ERR(regmap);
 173         }
 174
 175         priv->enable_gpios = devm_gpiod_get_array_optional(&i2c->dev, "enable", GPIOD_OUT_HIGH);
 176         if (IS_ERR(priv->enable_gpios)) {
 177                 dev_err(&i2c->dev, "Failed to get gpios\n");
 178                 return PTR_ERR(priv->enable_gpios);
 179         }
 180
 181         for (i = 0; i < DSV_OUT_MAX; i++) {
 182                 const struct regulator_desc *desc = rt4801_regulator_descs + i;
 183                 struct regulator_config config = { .dev = &i2c->dev, .driver_data = priv,
 184                                                    .regmap = regmap, };
 185                 struct regulator_dev *rdev;
 186                 unsigned int val;
 187                 int ret;
 188
 189                 /* initialize volt_sel variable */
 190                 ret = regmap_read(regmap, desc->vsel_reg, &val);
 191                 if (ret)
 192                         return ret;
 193
 194                 priv->volt_sel[i] = val & desc->vsel_mask;
 195
 196                 rdev = devm_regulator_register(&i2c->dev, desc, &config);
 197                 if (IS_ERR(rdev)) {
 198                         dev_err(&i2c->dev, "Failed to register [%d] regulator\n", i);
 199                         return PTR_ERR(rdev);
 200                 }
 201         }
 202
 203         return 0;
 204 }
 205
 206 static const struct of_device_id __maybe_unused rt4801_of_id[] = {
 207         { .compatible = "richtek,rt4801", },
 208         { },
 209 };
 210 MODULE_DEVICE_TABLE(of, rt4801_of_id);
 211
 212 static struct i2c_driver rt4801_driver = {
 213         .driver = {
 214                 .name = "rt4801",
 215                 .of_match_table = of_match_ptr(rt4801_of_id),
 216         },
 217         .probe_new = rt4801_probe,
 218 };
 219 module_i2c_driver(rt4801_driver);
 220
 221 MODULE_AUTHOR("ChiYuan Hwang <[email protected]>");
 222 MODULE_DESCRIPTION("Richtek RT4801 Display Bias Driver");
 223 MODULE_LICENSE("GPL v2");