| /* |
| * max8952.c - Voltage and current regulation for the Maxim 8952 |
| * |
| * Copyright (C) 2010 Samsung Electronics |
| * MyungJoo Ham <myungjoo.ham@samsung.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| #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.h> |
| #include <linux/gpio/consumer.h> |
| #include <linux/io.h> |
| #include <linux/of.h> |
| #include <linux/of_gpio.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; |
| |
| 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 (!gpio_is_valid(max8952->pdata->gpio_vid0) || |
| !gpio_is_valid(max8952->pdata->gpio_vid1)) { |
| /* DVS not supported */ |
| return -EPERM; |
| } |
| |
| max8952->vid0 = selector & 0x1; |
| max8952->vid1 = (selector >> 1) & 0x1; |
| gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0); |
| gpio_set_value(max8952->pdata->gpio_vid1, 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; |
| |
| pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0); |
| pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1); |
| |
| 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 = to_i2c_adapter(client->dev.parent); |
| 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, err = 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; |
| |
| if (gpio_is_valid(pdata->gpio_vid0) && |
| gpio_is_valid(pdata->gpio_vid1)) { |
| unsigned long gpio_flags; |
| |
| gpio_flags = max8952->vid0 ? |
| GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; |
| if (devm_gpio_request_one(&client->dev, pdata->gpio_vid0, |
| gpio_flags, "MAX8952 VID0")) |
| err = 1; |
| |
| gpio_flags = max8952->vid1 ? |
| GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; |
| if (devm_gpio_request_one(&client->dev, pdata->gpio_vid1, |
| gpio_flags, "MAX8952 VID1")) |
| err = 2; |
| } else |
| err = 3; |
| |
| if (err) { |
| dev_warn(&client->dev, "VID0/1 gpio invalid: " |
| "DVS not available.\n"); |
| max8952->vid0 = 0; |
| max8952->vid1 = 0; |
| /* Mark invalid */ |
| pdata->gpio_vid0 = -1; |
| pdata->gpio_vid1 = -1; |
| |
| /* 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"); |