| /* |
| * 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); |
| u8 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"); |