/* * max8952.c - Voltage and current regulation for the Maxim 8952 * * Copyright (C) 2010 Samsung Electronics * MyungJoo Ham * * 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 #include #include #include #include #include #include #include #include #include /* 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 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, unsigned *selector) { 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_vid1)) { /* 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 & 0x1; max8952->vid1 = (vid >> 1) & 0x1; *selector = vid; 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; max8952->rdev = regulator_register(®ulator, max8952->dev, &pdata->reg_data, max8952, NULL); 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 & 0x1; max8952->vid1 = (pdata->default_mode >> 1) & 0x1; 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) & 0x1); else err = 1; if (!gpio_request(pdata->gpio_vid1, "MAX8952 VID1")) gpio_direction_output(pdata->gpio_vid1, (pdata->default_mode >> 1) & 0x1); 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 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(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 "); MODULE_LICENSE("GPL");