|  | /* | 
|  | * max8952.c - Voltage and current regulation for the Maxim 8952 | 
|  | * | 
|  | * Copyright (C) 2010 Samsung Electronics | 
|  | * MyungJoo Ham <[email protected]> | 
|  | * | 
|  | * 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 <[email protected]>"); | 
|  | MODULE_LICENSE("GPL"); |