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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * max1586.c -- Voltage and current regulation for the Maxim 15864 *5 * Copyright (C) 2008 Robert Jarzmik6 */7#include <linux/module.h>8#include <linux/err.h>9#include <linux/i2c.h>10#include <linux/platform_device.h>11#include <linux/regulator/driver.h>12#include <linux/slab.h>13#include <linux/regulator/max1586.h>14#include <linux/of.h>15#include <linux/regulator/of_regulator.h>16 17#define MAX1586_V3_MAX_VSEL 3118#define MAX1586_V6_MAX_VSEL 319 20#define MAX1586_V3_MIN_UV 70000021#define MAX1586_V3_MAX_UV 147500022 23#define MAX1586_V6_MIN_UV 024#define MAX1586_V6_MAX_UV 300000025 26#define I2C_V3_SELECT (0 << 5)27#define I2C_V6_SELECT (1 << 5)28 29struct max1586_data {30 struct i2c_client *client;31 32 /* min/max V3 voltage */33 unsigned int min_uV;34 unsigned int max_uV;35 36 unsigned int v3_curr_sel;37 unsigned int v6_curr_sel;38};39 40/*41 * V6 voltage42 * On I2C bus, sending a "x" byte to the max1586 means :43 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)44 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.45 */46static const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };47 48/*49 * V3 voltage50 * On I2C bus, sending a "x" byte to the max1586 means :51 * set V3 to 0.700V + (x & 0x1f) * 0.025V52 * This voltage can be increased by external resistors53 * R24 and R25=100kOhm as described in the data sheet.54 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm55 */56static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev)57{58 struct max1586_data *max1586 = rdev_get_drvdata(rdev);59 60 return max1586->v3_curr_sel;61}62 63static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,64 unsigned selector)65{66 struct max1586_data *max1586 = rdev_get_drvdata(rdev);67 struct i2c_client *client = max1586->client;68 int ret;69 u8 v3_prog;70 71 dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",72 regulator_list_voltage_linear(rdev, selector) / 1000);73 74 v3_prog = I2C_V3_SELECT | (u8) selector;75 ret = i2c_smbus_write_byte(client, v3_prog);76 if (ret)77 return ret;78 79 max1586->v3_curr_sel = selector;80 81 return 0;82}83 84static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)85{86 struct max1586_data *max1586 = rdev_get_drvdata(rdev);87 88 return max1586->v6_curr_sel;89}90 91static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,92 unsigned int selector)93{94 struct max1586_data *max1586 = rdev_get_drvdata(rdev);95 struct i2c_client *client = max1586->client;96 u8 v6_prog;97 int ret;98 99 dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",100 rdev->desc->volt_table[selector] / 1000);101 102 v6_prog = I2C_V6_SELECT | (u8) selector;103 ret = i2c_smbus_write_byte(client, v6_prog);104 if (ret)105 return ret;106 107 max1586->v6_curr_sel = selector;108 109 return 0;110}111 112/*113 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back114 * the set up value.115 */116static const struct regulator_ops max1586_v3_ops = {117 .get_voltage_sel = max1586_v3_get_voltage_sel,118 .set_voltage_sel = max1586_v3_set_voltage_sel,119 .list_voltage = regulator_list_voltage_linear,120 .map_voltage = regulator_map_voltage_linear,121};122 123static const struct regulator_ops max1586_v6_ops = {124 .get_voltage_sel = max1586_v6_get_voltage_sel,125 .set_voltage_sel = max1586_v6_set_voltage_sel,126 .list_voltage = regulator_list_voltage_table,127};128 129static struct regulator_desc max1586_reg[] = {130 {131 .name = "Output_V3",132 .id = MAX1586_V3,133 .ops = &max1586_v3_ops,134 .type = REGULATOR_VOLTAGE,135 .n_voltages = MAX1586_V3_MAX_VSEL + 1,136 .owner = THIS_MODULE,137 },138 {139 .name = "Output_V6",140 .id = MAX1586_V6,141 .ops = &max1586_v6_ops,142 .type = REGULATOR_VOLTAGE,143 .n_voltages = MAX1586_V6_MAX_VSEL + 1,144 .volt_table = v6_voltages_uv,145 .owner = THIS_MODULE,146 },147};148 149static int of_get_max1586_platform_data(struct device *dev,150 struct max1586_platform_data *pdata)151{152 struct max1586_subdev_data *sub;153 struct of_regulator_match rmatch[ARRAY_SIZE(max1586_reg)] = { };154 struct device_node *np = dev->of_node;155 int i, matched;156 157 if (of_property_read_u32(np, "v3-gain",158 &pdata->v3_gain) < 0) {159 dev_err(dev, "%pOF has no 'v3-gain' property\n", np);160 return -EINVAL;161 }162 163 np = of_get_child_by_name(np, "regulators");164 if (!np) {165 dev_err(dev, "missing 'regulators' subnode in DT\n");166 return -EINVAL;167 }168 169 for (i = 0; i < ARRAY_SIZE(rmatch); i++)170 rmatch[i].name = max1586_reg[i].name;171 172 matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));173 of_node_put(np);174 /*175 * If matched is 0, ie. neither Output_V3 nor Output_V6 have been found,176 * return 0, which signals the normal situation where no subregulator is177 * available. This is normal because the max1586 doesn't provide any178 * readback support, so the subregulators can't report any status179 * anyway. If matched < 0, return the error.180 */181 if (matched <= 0)182 return matched;183 184 pdata->subdevs = devm_kcalloc(dev,185 matched,186 sizeof(struct max1586_subdev_data),187 GFP_KERNEL);188 if (!pdata->subdevs)189 return -ENOMEM;190 191 pdata->num_subdevs = matched;192 sub = pdata->subdevs;193 194 for (i = 0; i < matched; i++) {195 sub->id = i;196 sub->name = rmatch[i].of_node->name;197 sub->platform_data = rmatch[i].init_data;198 sub++;199 }200 201 return 0;202}203 204static const struct of_device_id __maybe_unused max1586_of_match[] = {205 { .compatible = "maxim,max1586", },206 {},207};208MODULE_DEVICE_TABLE(of, max1586_of_match);209 210static int max1586_pmic_probe(struct i2c_client *client)211{212 struct max1586_platform_data *pdata, pdata_of;213 struct regulator_config config = { };214 struct max1586_data *max1586;215 int i, id, ret;216 217 pdata = dev_get_platdata(&client->dev);218 if (client->dev.of_node && !pdata) {219 ret = of_get_max1586_platform_data(&client->dev, &pdata_of);220 if (ret < 0)221 return ret;222 pdata = &pdata_of;223 }224 225 max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data),226 GFP_KERNEL);227 if (!max1586)228 return -ENOMEM;229 230 max1586->client = client;231 232 if (!pdata->v3_gain)233 return -EINVAL;234 235 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;236 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;237 238 /* Set curr_sel to default voltage on power-up */239 max1586->v3_curr_sel = 24; /* 1.3V */240 max1586->v6_curr_sel = 0;241 242 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {243 struct regulator_dev *rdev;244 245 id = pdata->subdevs[i].id;246 if (!pdata->subdevs[i].platform_data)247 continue;248 if (id < MAX1586_V3 || id > MAX1586_V6) {249 dev_err(&client->dev, "invalid regulator id %d\n", id);250 return -EINVAL;251 }252 253 if (id == MAX1586_V3) {254 max1586_reg[id].min_uV = max1586->min_uV;255 max1586_reg[id].uV_step =256 (max1586->max_uV - max1586->min_uV) /257 MAX1586_V3_MAX_VSEL;258 }259 260 config.dev = &client->dev;261 config.init_data = pdata->subdevs[i].platform_data;262 config.driver_data = max1586;263 264 rdev = devm_regulator_register(&client->dev,265 &max1586_reg[id], &config);266 if (IS_ERR(rdev)) {267 dev_err(&client->dev, "failed to register %s\n",268 max1586_reg[id].name);269 return PTR_ERR(rdev);270 }271 }272 273 i2c_set_clientdata(client, max1586);274 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");275 return 0;276}277 278static const struct i2c_device_id max1586_id[] = {279 { "max1586" },280 { }281};282MODULE_DEVICE_TABLE(i2c, max1586_id);283 284static struct i2c_driver max1586_pmic_driver = {285 .probe = max1586_pmic_probe,286 .driver = {287 .name = "max1586",288 .probe_type = PROBE_PREFER_ASYNCHRONOUS,289 .of_match_table = of_match_ptr(max1586_of_match),290 },291 .id_table = max1586_id,292};293 294static int __init max1586_pmic_init(void)295{296 return i2c_add_driver(&max1586_pmic_driver);297}298subsys_initcall(max1586_pmic_init);299 300static void __exit max1586_pmic_exit(void)301{302 i2c_del_driver(&max1586_pmic_driver);303}304module_exit(max1586_pmic_exit);305 306/* Module information */307MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");308MODULE_AUTHOR("Robert Jarzmik");309MODULE_LICENSE("GPL");310