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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * max8952.c - Voltage and current regulation for the Maxim 89524 *5 * Copyright (C) 2010 Samsung Electronics6 * MyungJoo Ham <myungjoo.ham@samsung.com>7 */8 9#include <linux/module.h>10#include <linux/init.h>11#include <linux/i2c.h>12#include <linux/err.h>13#include <linux/platform_device.h>14#include <linux/regulator/driver.h>15#include <linux/regulator/max8952.h>16#include <linux/gpio/consumer.h>17#include <linux/io.h>18#include <linux/of.h>19#include <linux/regulator/of_regulator.h>20#include <linux/slab.h>21 22/* Registers */23enum {24 MAX8952_REG_MODE0,25 MAX8952_REG_MODE1,26 MAX8952_REG_MODE2,27 MAX8952_REG_MODE3,28 MAX8952_REG_CONTROL,29 MAX8952_REG_SYNC,30 MAX8952_REG_RAMP,31 MAX8952_REG_CHIP_ID1,32 MAX8952_REG_CHIP_ID2,33};34 35struct max8952_data {36 struct i2c_client *client;37 struct max8952_platform_data *pdata;38 struct gpio_desc *vid0_gpiod;39 struct gpio_desc *vid1_gpiod;40 bool vid0;41 bool vid1;42};43 44static int max8952_read_reg(struct max8952_data *max8952, u8 reg)45{46 int ret = i2c_smbus_read_byte_data(max8952->client, reg);47 48 if (ret > 0)49 ret &= 0xff;50 51 return ret;52}53 54static int max8952_write_reg(struct max8952_data *max8952,55 u8 reg, u8 value)56{57 return i2c_smbus_write_byte_data(max8952->client, reg, value);58}59 60static int max8952_list_voltage(struct regulator_dev *rdev,61 unsigned int selector)62{63 struct max8952_data *max8952 = rdev_get_drvdata(rdev);64 65 if (rdev_get_id(rdev) != 0)66 return -EINVAL;67 68 return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;69}70 71static int max8952_get_voltage_sel(struct regulator_dev *rdev)72{73 struct max8952_data *max8952 = rdev_get_drvdata(rdev);74 u8 vid = 0;75 76 if (max8952->vid0)77 vid += 1;78 if (max8952->vid1)79 vid += 2;80 81 return vid;82}83 84static int max8952_set_voltage_sel(struct regulator_dev *rdev,85 unsigned selector)86{87 struct max8952_data *max8952 = rdev_get_drvdata(rdev);88 89 if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) {90 /* DVS not supported */91 return -EPERM;92 }93 94 max8952->vid0 = selector & 0x1;95 max8952->vid1 = (selector >> 1) & 0x1;96 gpiod_set_value(max8952->vid0_gpiod, max8952->vid0);97 gpiod_set_value(max8952->vid1_gpiod, max8952->vid1);98 99 return 0;100}101 102static const struct regulator_ops max8952_ops = {103 .list_voltage = max8952_list_voltage,104 .get_voltage_sel = max8952_get_voltage_sel,105 .set_voltage_sel = max8952_set_voltage_sel,106};107 108static const struct regulator_desc regulator = {109 .name = "MAX8952_VOUT",110 .id = 0,111 .n_voltages = MAX8952_NUM_DVS_MODE,112 .ops = &max8952_ops,113 .type = REGULATOR_VOLTAGE,114 .owner = THIS_MODULE,115};116 117#ifdef CONFIG_OF118static const struct of_device_id max8952_dt_match[] = {119 { .compatible = "maxim,max8952" },120 {},121};122MODULE_DEVICE_TABLE(of, max8952_dt_match);123 124static struct max8952_platform_data *max8952_parse_dt(struct device *dev)125{126 struct max8952_platform_data *pd;127 struct device_node *np = dev->of_node;128 int ret;129 int i;130 131 pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);132 if (!pd)133 return NULL;134 135 if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))136 dev_warn(dev, "Default mode not specified, assuming 0\n");137 138 ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",139 pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));140 if (ret) {141 dev_err(dev, "max8952,dvs-mode-microvolt property not specified");142 return NULL;143 }144 145 for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {146 if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {147 dev_err(dev, "DVS voltage %d out of range\n", i);148 return NULL;149 }150 pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;151 }152 153 if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))154 dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");155 156 if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))157 dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");158 159 pd->reg_data = of_get_regulator_init_data(dev, np, ®ulator);160 if (!pd->reg_data) {161 dev_err(dev, "Failed to parse regulator init data\n");162 return NULL;163 }164 165 return pd;166}167#else168static struct max8952_platform_data *max8952_parse_dt(struct device *dev)169{170 return NULL;171}172#endif173 174static int max8952_pmic_probe(struct i2c_client *client)175{176 struct i2c_adapter *adapter = client->adapter;177 struct max8952_platform_data *pdata = dev_get_platdata(&client->dev);178 struct regulator_config config = { };179 struct max8952_data *max8952;180 struct regulator_dev *rdev;181 struct gpio_desc *gpiod;182 enum gpiod_flags gflags;183 184 int ret = 0;185 186 if (client->dev.of_node)187 pdata = max8952_parse_dt(&client->dev);188 189 if (!pdata) {190 dev_err(&client->dev, "Require the platform data\n");191 return -EINVAL;192 }193 194 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))195 return -EIO;196 197 max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),198 GFP_KERNEL);199 if (!max8952)200 return -ENOMEM;201 202 max8952->client = client;203 max8952->pdata = pdata;204 205 config.dev = &client->dev;206 config.init_data = pdata->reg_data;207 config.driver_data = max8952;208 config.of_node = client->dev.of_node;209 210 if (pdata->reg_data->constraints.boot_on)211 gflags = GPIOD_OUT_HIGH;212 else213 gflags = GPIOD_OUT_LOW;214 gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;215 /*216 * Do not use devm* here: the regulator core takes over the217 * lifecycle management of the GPIO descriptor.218 */219 gpiod = gpiod_get_optional(&client->dev,220 "max8952,en",221 gflags);222 if (IS_ERR(gpiod))223 return PTR_ERR(gpiod);224 if (gpiod)225 config.ena_gpiod = gpiod;226 227 rdev = devm_regulator_register(&client->dev, ®ulator, &config);228 if (IS_ERR(rdev)) {229 ret = PTR_ERR(rdev);230 dev_err(&client->dev, "regulator init failed (%d)\n", ret);231 return ret;232 }233 234 max8952->vid0 = pdata->default_mode & 0x1;235 max8952->vid1 = (pdata->default_mode >> 1) & 0x1;236 237 /* Fetch vid0 and vid1 GPIOs if available */238 gflags = max8952->vid0 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;239 max8952->vid0_gpiod = devm_gpiod_get_index_optional(&client->dev,240 "max8952,vid",241 0, gflags);242 if (IS_ERR(max8952->vid0_gpiod))243 return PTR_ERR(max8952->vid0_gpiod);244 gflags = max8952->vid1 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;245 max8952->vid1_gpiod = devm_gpiod_get_index_optional(&client->dev,246 "max8952,vid",247 1, gflags);248 if (IS_ERR(max8952->vid1_gpiod))249 return PTR_ERR(max8952->vid1_gpiod);250 251 /* If either VID GPIO is missing just disable this */252 if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) {253 dev_warn(&client->dev, "VID0/1 gpio invalid: "254 "DVS not available.\n");255 max8952->vid0 = 0;256 max8952->vid1 = 0;257 /* Make sure if we have any descriptors they get set to low */258 if (max8952->vid0_gpiod)259 gpiod_set_value(max8952->vid0_gpiod, 0);260 if (max8952->vid1_gpiod)261 gpiod_set_value(max8952->vid1_gpiod, 0);262 263 /* Disable Pulldown of EN only */264 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);265 266 dev_err(&client->dev, "DVS modes disabled because VID0 and VID1"267 " do not have proper controls.\n");268 } else {269 /*270 * Disable Pulldown on EN, VID0, VID1 to reduce271 * leakage current of MAX8952 assuming that MAX8952272 * is turned on (EN==1). Note that without having VID0/1273 * properly connected, turning pulldown off can be274 * problematic. Thus, turn this off only when they are275 * controllable by GPIO.276 */277 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);278 }279 280 max8952_write_reg(max8952, MAX8952_REG_MODE0,281 (max8952_read_reg(max8952,282 MAX8952_REG_MODE0) & 0xC0) |283 (pdata->dvs_mode[0] & 0x3F));284 max8952_write_reg(max8952, MAX8952_REG_MODE1,285 (max8952_read_reg(max8952,286 MAX8952_REG_MODE1) & 0xC0) |287 (pdata->dvs_mode[1] & 0x3F));288 max8952_write_reg(max8952, MAX8952_REG_MODE2,289 (max8952_read_reg(max8952,290 MAX8952_REG_MODE2) & 0xC0) |291 (pdata->dvs_mode[2] & 0x3F));292 max8952_write_reg(max8952, MAX8952_REG_MODE3,293 (max8952_read_reg(max8952,294 MAX8952_REG_MODE3) & 0xC0) |295 (pdata->dvs_mode[3] & 0x3F));296 297 max8952_write_reg(max8952, MAX8952_REG_SYNC,298 (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |299 ((pdata->sync_freq & 0x3) << 6));300 max8952_write_reg(max8952, MAX8952_REG_RAMP,301 (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |302 ((pdata->ramp_speed & 0x7) << 5));303 304 i2c_set_clientdata(client, max8952);305 306 return 0;307}308 309static const struct i2c_device_id max8952_ids[] = {310 { "max8952" },311 { }312};313MODULE_DEVICE_TABLE(i2c, max8952_ids);314 315static struct i2c_driver max8952_pmic_driver = {316 .probe = max8952_pmic_probe,317 .driver = {318 .name = "max8952",319 .probe_type = PROBE_PREFER_ASYNCHRONOUS,320 .of_match_table = of_match_ptr(max8952_dt_match),321 },322 .id_table = max8952_ids,323};324 325static int __init max8952_pmic_init(void)326{327 return i2c_add_driver(&max8952_pmic_driver);328}329subsys_initcall(max8952_pmic_init);330 331static void __exit max8952_pmic_exit(void)332{333 i2c_del_driver(&max8952_pmic_driver);334}335module_exit(max8952_pmic_exit);336 337MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");338MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");339MODULE_LICENSE("GPL");340