// SPDX-License-Identifier: GPL-2.0-or-later /* * max8952.c - Voltage and current regulation for the Maxim 8952 * * Copyright (C) 2010 Samsung Electronics * MyungJoo Ham <myungjoo.ham@samsung.com> */ #include <linux/module.h> #include <linux/init.h> #include <linux/i2c.h> #include <linux/err.h> #include <linux/platform_device.h> #include <linux/regulator/driver.h> #include <linux/regulator/max8952.h> #include <linux/gpio/consumer.h> #include <linux/io.h> #include <linux/of.h> #include <linux/regulator/of_regulator.h> #include <linux/slab.h> /* Registers */ enum { MAX8952_REG_MODE0, MAX8952_REG_MODE1, MAX8952_REG_MODE2, MAX8952_REG_MODE3, MAX8952_REG_CONTROL, MAX8952_REG_SYNC, MAX8952_REG_RAMP, MAX8952_REG_CHIP_ID1, MAX8952_REG_CHIP_ID2, }; struct max8952_data { struct i2c_client *client; struct max8952_platform_data *pdata; struct gpio_desc *vid0_gpiod; struct gpio_desc *vid1_gpiod; bool vid0; bool vid1; }; static int max8952_read_reg(struct max8952_data *max8952, u8 reg) { int ret = i2c_smbus_read_byte_data(max8952->client, reg); if (ret > 0) ret &= 0xff; return ret; } static int max8952_write_reg(struct max8952_data *max8952, u8 reg, u8 value) { return i2c_smbus_write_byte_data(max8952->client, reg, value); } static int max8952_list_voltage(struct regulator_dev *rdev, unsigned int selector) { struct max8952_data *max8952 = rdev_get_drvdata(rdev); if (rdev_get_id(rdev) != 0) return -EINVAL; return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000; } static int max8952_get_voltage_sel(struct regulator_dev *rdev) { struct max8952_data *max8952 = rdev_get_drvdata(rdev); u8 vid = 0; if (max8952->vid0) vid += 1; if (max8952->vid1) vid += 2; return vid; } static int max8952_set_voltage_sel(struct regulator_dev *rdev, unsigned selector) { struct max8952_data *max8952 = rdev_get_drvdata(rdev); if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) { /* DVS not supported */ return -EPERM; } max8952->vid0 = selector & 0x1; max8952->vid1 = (selector >> 1) & 0x1; gpiod_set_value(max8952->vid0_gpiod, max8952->vid0); gpiod_set_value(max8952->vid1_gpiod, max8952->vid1); return 0; } static const struct regulator_ops max8952_ops = { .list_voltage = max8952_list_voltage, .get_voltage_sel = max8952_get_voltage_sel, .set_voltage_sel = max8952_set_voltage_sel, }; static const struct regulator_desc regulator = { .name = "MAX8952_VOUT", .id = 0, .n_voltages = MAX8952_NUM_DVS_MODE, .ops = &max8952_ops, .type = REGULATOR_VOLTAGE, .owner = THIS_MODULE, }; #ifdef CONFIG_OF static const struct of_device_id max8952_dt_match[] = { { .compatible = "maxim,max8952" }, {}, }; MODULE_DEVICE_TABLE(of, max8952_dt_match); static struct max8952_platform_data *max8952_parse_dt(struct device *dev) { struct max8952_platform_data *pd; struct device_node *np = dev->of_node; int ret; int i; pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL); if (!pd) return NULL; if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode)) dev_warn(dev, "Default mode not specified, assuming 0\n"); ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt", pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode)); if (ret) { dev_err(dev, "max8952,dvs-mode-microvolt property not specified"); return NULL; } for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) { if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) { dev_err(dev, "DVS voltage %d out of range\n", i); return NULL; } pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000; } if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq)) dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n"); if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed)) dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n"); pd->reg_data = of_get_regulator_init_data(dev, np, ®ulator); if (!pd->reg_data) { dev_err(dev, "Failed to parse regulator init data\n"); return NULL; } return pd; } #else static struct max8952_platform_data *max8952_parse_dt(struct device *dev) { return NULL; } #endif static int max8952_pmic_probe(struct i2c_client *client, const struct i2c_device_id *i2c_id) { struct i2c_adapter *adapter = client->adapter; struct max8952_platform_data *pdata = dev_get_platdata(&client->dev); struct regulator_config config = { }; struct max8952_data *max8952; struct regulator_dev *rdev; struct gpio_desc *gpiod; enum gpiod_flags gflags; int ret = 0; if (client->dev.of_node) pdata = max8952_parse_dt(&client->dev); if (!pdata) { dev_err(&client->dev, "Require the platform data\n"); return -EINVAL; } if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) return -EIO; max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data), GFP_KERNEL); if (!max8952) return -ENOMEM; max8952->client = client; max8952->pdata = pdata; config.dev = &client->dev; config.init_data = pdata->reg_data; config.driver_data = max8952; config.of_node = client->dev.of_node; if (pdata->reg_data->constraints.boot_on) gflags = GPIOD_OUT_HIGH; else gflags = GPIOD_OUT_LOW; gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE; /* * Do not use devm* here: the regulator core takes over the * lifecycle management of the GPIO descriptor. */ gpiod = gpiod_get_optional(&client->dev, "max8952,en", gflags); if (IS_ERR(gpiod)) return PTR_ERR(gpiod); if (gpiod) config.ena_gpiod = gpiod; rdev = devm_regulator_register(&client->dev, ®ulator, &config); if (IS_ERR(rdev)) { ret = PTR_ERR(rdev); dev_err(&client->dev, "regulator init failed (%d)\n", ret); return ret; } max8952->vid0 = pdata->default_mode & 0x1; max8952->vid1 = (pdata->default_mode >> 1) & 0x1; /* Fetch vid0 and vid1 GPIOs if available */ gflags = max8952->vid0 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; max8952->vid0_gpiod = devm_gpiod_get_index_optional(&client->dev, "max8952,vid", 0, gflags); if (IS_ERR(max8952->vid0_gpiod)) return PTR_ERR(max8952->vid0_gpiod); gflags = max8952->vid1 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; max8952->vid1_gpiod = devm_gpiod_get_index_optional(&client->dev, "max8952,vid", 1, gflags); if (IS_ERR(max8952->vid1_gpiod)) return PTR_ERR(max8952->vid1_gpiod); /* If either VID GPIO is missing just disable this */ if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) { dev_warn(&client->dev, "VID0/1 gpio invalid: " "DVS not available.\n"); max8952->vid0 = 0; max8952->vid1 = 0; /* Make sure if we have any descriptors they get set to low */ if (max8952->vid0_gpiod) gpiod_set_value(max8952->vid0_gpiod, 0); if (max8952->vid1_gpiod) gpiod_set_value(max8952->vid1_gpiod, 0); /* Disable Pulldown of EN only */ max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60); dev_err(&client->dev, "DVS modes disabled because VID0 and VID1" " do not have proper controls.\n"); } else { /* * Disable Pulldown on EN, VID0, VID1 to reduce * leakage current of MAX8952 assuming that MAX8952 * is turned on (EN==1). Note that without having VID0/1 * properly connected, turning pulldown off can be * problematic. Thus, turn this off only when they are * controllable by GPIO. */ max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0); } max8952_write_reg(max8952, MAX8952_REG_MODE0, (max8952_read_reg(max8952, MAX8952_REG_MODE0) & 0xC0) | (pdata->dvs_mode[0] & 0x3F)); max8952_write_reg(max8952, MAX8952_REG_MODE1, (max8952_read_reg(max8952, MAX8952_REG_MODE1) & 0xC0) | (pdata->dvs_mode[1] & 0x3F)); max8952_write_reg(max8952, MAX8952_REG_MODE2, (max8952_read_reg(max8952, MAX8952_REG_MODE2) & 0xC0) | (pdata->dvs_mode[2] & 0x3F)); max8952_write_reg(max8952, MAX8952_REG_MODE3, (max8952_read_reg(max8952, MAX8952_REG_MODE3) & 0xC0) | (pdata->dvs_mode[3] & 0x3F)); max8952_write_reg(max8952, MAX8952_REG_SYNC, (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) | ((pdata->sync_freq & 0x3) << 6)); max8952_write_reg(max8952, MAX8952_REG_RAMP, (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) | ((pdata->ramp_speed & 0x7) << 5)); i2c_set_clientdata(client, max8952); return 0; } static const struct i2c_device_id max8952_ids[] = { { "max8952", 0 }, { }, }; MODULE_DEVICE_TABLE(i2c, max8952_ids); static struct i2c_driver max8952_pmic_driver = { .probe = max8952_pmic_probe, .driver = { .name = "max8952", .of_match_table = of_match_ptr(max8952_dt_match), }, .id_table = max8952_ids, }; static int __init max8952_pmic_init(void) { return i2c_add_driver(&max8952_pmic_driver); } subsys_initcall(max8952_pmic_init); static void __exit max8952_pmic_exit(void) { i2c_del_driver(&max8952_pmic_driver); } module_exit(max8952_pmic_exit); MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver"); MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); MODULE_LICENSE("GPL");