diff options
Diffstat (limited to 'drivers/regulator/max8952.c')
| -rw-r--r-- | drivers/regulator/max8952.c | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/drivers/regulator/max8952.c b/drivers/regulator/max8952.c new file mode 100644 index 00000000000..0d5dda4fd91 --- /dev/null +++ b/drivers/regulator/max8952.c @@ -0,0 +1,366 @@ +/* + * 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/mutex.h> +#include <linux/gpio.h> +#include <linux/io.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 device *dev; + struct mutex mutex; + struct max8952_platform_data *pdata; + struct regulator_dev *rdev; + + bool vid0; + bool vid1; + bool en; +}; + +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_voltage(struct max8952_data *max8952, u8 mode) +{ + return (max8952->pdata->dvs_mode[mode] * 10 + 770) * 1000; +} + +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_voltage(max8952, selector); +} + +static int max8952_is_enabled(struct regulator_dev *rdev) +{ + struct max8952_data *max8952 = rdev_get_drvdata(rdev); + return max8952->en; +} + +static int max8952_enable(struct regulator_dev *rdev) +{ + struct max8952_data *max8952 = rdev_get_drvdata(rdev); + + /* If not valid, assume "ALWAYS_HIGH" */ + if (gpio_is_valid(max8952->pdata->gpio_en)) + gpio_set_value(max8952->pdata->gpio_en, 1); + + max8952->en = true; + return 0; +} + +static int max8952_disable(struct regulator_dev *rdev) +{ + struct max8952_data *max8952 = rdev_get_drvdata(rdev); + + /* If not valid, assume "ALWAYS_HIGH" -> not permitted */ + if (gpio_is_valid(max8952->pdata->gpio_en)) + gpio_set_value(max8952->pdata->gpio_en, 0); + else + return -EPERM; + + max8952->en = false; + return 0; +} + +static int max8952_get_voltage(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 max8952_voltage(max8952, vid); +} + +static int max8952_set_voltage(struct regulator_dev *rdev, + int min_uV, int max_uV) +{ + struct max8952_data *max8952 = rdev_get_drvdata(rdev); + s8 vid = -1, i; + + if (!gpio_is_valid(max8952->pdata->gpio_vid0) || + !gpio_is_valid(max8952->pdata->gpio_vid0)) { + /* DVS not supported */ + return -EPERM; + } + + for (i = 0; i < MAX8952_NUM_DVS_MODE; i++) { + int volt = max8952_voltage(max8952, i); + + /* Set the voltage as low as possible within the range */ + if (volt <= max_uV && volt >= min_uV) + if (vid == -1 || max8952_voltage(max8952, vid) > volt) + vid = i; + } + + if (vid >= 0 && vid < MAX8952_NUM_DVS_MODE) { + max8952->vid0 = (vid % 2 == 1); + max8952->vid1 = (((vid >> 1) % 2) == 1); + gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0); + gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1); + } else + return -EINVAL; + + return 0; +} + +static struct regulator_ops max8952_ops = { + .list_voltage = max8952_list_voltage, + .is_enabled = max8952_is_enabled, + .enable = max8952_enable, + .disable = max8952_disable, + .get_voltage = max8952_get_voltage, + .set_voltage = max8952_set_voltage, + .set_suspend_disable = max8952_disable, +}; + +static struct regulator_desc regulator = { + .name = "MAX8952_VOUT", + .id = 0, + .n_voltages = MAX8952_NUM_DVS_MODE, + .ops = &max8952_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, +}; + +static int __devinit 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 = client->dev.platform_data; + struct max8952_data *max8952; + + int ret = 0, err = 0; + + 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 = kzalloc(sizeof(struct max8952_data), GFP_KERNEL); + if (!max8952) + return -ENOMEM; + + max8952->client = client; + max8952->dev = &client->dev; + max8952->pdata = pdata; + mutex_init(&max8952->mutex); + + max8952->rdev = regulator_register(®ulator, max8952->dev, + &pdata->reg_data, max8952); + + if (IS_ERR(max8952->rdev)) { + ret = PTR_ERR(max8952->rdev); + dev_err(max8952->dev, "regulator init failed (%d)\n", ret); + goto err_reg; + } + + max8952->en = !!(pdata->reg_data.constraints.boot_on); + max8952->vid0 = (pdata->default_mode % 2) == 1; + max8952->vid1 = ((pdata->default_mode >> 1) % 2) == 1; + + if (gpio_is_valid(pdata->gpio_en)) { + if (!gpio_request(pdata->gpio_en, "MAX8952 EN")) + gpio_direction_output(pdata->gpio_en, max8952->en); + else + err = 1; + } else + err = 2; + + if (err) { + dev_info(max8952->dev, "EN gpio invalid: assume that EN" + "is always High\n"); + max8952->en = 1; + pdata->gpio_en = -1; /* Mark invalid */ + } + + err = 0; + + if (gpio_is_valid(pdata->gpio_vid0) && + gpio_is_valid(pdata->gpio_vid1)) { + if (!gpio_request(pdata->gpio_vid0, "MAX8952 VID0")) + gpio_direction_output(pdata->gpio_vid0, + (pdata->default_mode) % 2); + else + err = 1; + + if (!gpio_request(pdata->gpio_vid1, "MAX8952 VID1")) + gpio_direction_output(pdata->gpio_vid1, + (pdata->default_mode >> 1) % 2); + else { + if (!err) + gpio_free(pdata->gpio_vid0); + err = 2; + } + + } else + err = 3; + + if (err) { + dev_warn(max8952->dev, "VID0/1 gpio invalid: " + "DVS not avilable.\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(max8952->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; + +err_reg: + kfree(max8952); + return ret; +} + +static int __devexit max8952_pmic_remove(struct i2c_client *client) +{ + struct max8952_data *max8952 = i2c_get_clientdata(client); + struct max8952_platform_data *pdata = max8952->pdata; + struct regulator_dev *rdev = max8952->rdev; + + regulator_unregister(rdev); + + gpio_free(pdata->gpio_vid0); + gpio_free(pdata->gpio_vid1); + gpio_free(pdata->gpio_en); + + kfree(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, + .remove = __devexit_p(max8952_pmic_remove), + .driver = { + .name = "max8952", + }, + .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"); |