|  | /* | 
|  | * max1586.c  --  Voltage and current regulation for the Maxim 1586 | 
|  | * | 
|  | * Copyright (C) 2008 Robert Jarzmik | 
|  | * | 
|  | * 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/err.h> | 
|  | #include <linux/i2c.h> | 
|  | #include <linux/platform_device.h> | 
|  | #include <linux/regulator/driver.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/regulator/max1586.h> | 
|  |  | 
|  | #define MAX1586_V3_MAX_VSEL 31 | 
|  | #define MAX1586_V6_MAX_VSEL 3 | 
|  |  | 
|  | #define MAX1586_V3_MIN_UV   700000 | 
|  | #define MAX1586_V3_MAX_UV  1475000 | 
|  |  | 
|  | #define MAX1586_V6_MIN_UV        0 | 
|  | #define MAX1586_V6_MAX_UV  3000000 | 
|  |  | 
|  | #define I2C_V3_SELECT (0 << 5) | 
|  | #define I2C_V6_SELECT (1 << 5) | 
|  |  | 
|  | struct max1586_data { | 
|  | struct i2c_client *client; | 
|  |  | 
|  | /* min/max V3 voltage */ | 
|  | unsigned int min_uV; | 
|  | unsigned int max_uV; | 
|  |  | 
|  | struct regulator_dev *rdev[0]; | 
|  | }; | 
|  |  | 
|  | /* | 
|  | * V3 voltage | 
|  | * On I2C bus, sending a "x" byte to the max1586 means : | 
|  | *   set V3 to 0.700V + (x & 0x1f) * 0.025V | 
|  | * This voltage can be increased by external resistors | 
|  | * R24 and R25=100kOhm as described in the data sheet. | 
|  | * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm | 
|  | */ | 
|  | static int max1586_v3_calc_voltage(struct max1586_data *max1586, | 
|  | unsigned selector) | 
|  | { | 
|  | unsigned range_uV = max1586->max_uV - max1586->min_uV; | 
|  |  | 
|  | return max1586->min_uV + (selector * range_uV / MAX1586_V3_MAX_VSEL); | 
|  | } | 
|  |  | 
|  | static int max1586_v3_set(struct regulator_dev *rdev, int min_uV, int max_uV, | 
|  | unsigned *selector) | 
|  | { | 
|  | struct max1586_data *max1586 = rdev_get_drvdata(rdev); | 
|  | struct i2c_client *client = max1586->client; | 
|  | unsigned range_uV = max1586->max_uV - max1586->min_uV; | 
|  | u8 v3_prog; | 
|  |  | 
|  | if (min_uV > max1586->max_uV || max_uV < max1586->min_uV) | 
|  | return -EINVAL; | 
|  | if (min_uV < max1586->min_uV) | 
|  | min_uV = max1586->min_uV; | 
|  |  | 
|  | *selector = ((min_uV - max1586->min_uV) * MAX1586_V3_MAX_VSEL + | 
|  | range_uV - 1) / range_uV; | 
|  | if (max1586_v3_calc_voltage(max1586, *selector) > max_uV) | 
|  | return -EINVAL; | 
|  |  | 
|  | dev_dbg(&client->dev, "changing voltage v3 to %dmv\n", | 
|  | max1586_v3_calc_voltage(max1586, *selector) / 1000); | 
|  |  | 
|  | v3_prog = I2C_V3_SELECT | (u8) *selector; | 
|  | return i2c_smbus_write_byte(client, v3_prog); | 
|  | } | 
|  |  | 
|  | static int max1586_v3_list(struct regulator_dev *rdev, unsigned selector) | 
|  | { | 
|  | struct max1586_data *max1586 = rdev_get_drvdata(rdev); | 
|  |  | 
|  | if (selector > MAX1586_V3_MAX_VSEL) | 
|  | return -EINVAL; | 
|  | return max1586_v3_calc_voltage(max1586, selector); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * V6 voltage | 
|  | * On I2C bus, sending a "x" byte to the max1586 means : | 
|  | *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3) | 
|  | * As regulator framework doesn't accept voltages to be 0V, we use 1uV. | 
|  | */ | 
|  | static int max1586_v6_calc_voltage(unsigned selector) | 
|  | { | 
|  | static int voltages_uv[] = { 1, 1800000, 2500000, 3000000 }; | 
|  |  | 
|  | return voltages_uv[selector]; | 
|  | } | 
|  |  | 
|  | static int max1586_v6_set(struct regulator_dev *rdev, int min_uV, int max_uV, | 
|  | unsigned int *selector) | 
|  | { | 
|  | struct i2c_client *client = rdev_get_drvdata(rdev); | 
|  | u8 v6_prog; | 
|  |  | 
|  | if (min_uV < MAX1586_V6_MIN_UV || min_uV > MAX1586_V6_MAX_UV) | 
|  | return -EINVAL; | 
|  | if (max_uV < MAX1586_V6_MIN_UV || max_uV > MAX1586_V6_MAX_UV) | 
|  | return -EINVAL; | 
|  |  | 
|  | if (min_uV < 1800000) | 
|  | *selector = 0; | 
|  | else if (min_uV < 2500000) | 
|  | *selector = 1; | 
|  | else if (min_uV < 3000000) | 
|  | *selector = 2; | 
|  | else if (min_uV >= 3000000) | 
|  | *selector = 3; | 
|  |  | 
|  | if (max1586_v6_calc_voltage(*selector) > max_uV) | 
|  | return -EINVAL; | 
|  |  | 
|  | dev_dbg(&client->dev, "changing voltage v6 to %dmv\n", | 
|  | max1586_v6_calc_voltage(*selector) / 1000); | 
|  |  | 
|  | v6_prog = I2C_V6_SELECT | (u8) *selector; | 
|  | return i2c_smbus_write_byte(client, v6_prog); | 
|  | } | 
|  |  | 
|  | static int max1586_v6_list(struct regulator_dev *rdev, unsigned selector) | 
|  | { | 
|  | if (selector > MAX1586_V6_MAX_VSEL) | 
|  | return -EINVAL; | 
|  | return max1586_v6_calc_voltage(selector); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back | 
|  | * the set up value. | 
|  | */ | 
|  | static struct regulator_ops max1586_v3_ops = { | 
|  | .set_voltage = max1586_v3_set, | 
|  | .list_voltage = max1586_v3_list, | 
|  | }; | 
|  |  | 
|  | static struct regulator_ops max1586_v6_ops = { | 
|  | .set_voltage = max1586_v6_set, | 
|  | .list_voltage = max1586_v6_list, | 
|  | }; | 
|  |  | 
|  | static struct regulator_desc max1586_reg[] = { | 
|  | { | 
|  | .name = "Output_V3", | 
|  | .id = MAX1586_V3, | 
|  | .ops = &max1586_v3_ops, | 
|  | .type = REGULATOR_VOLTAGE, | 
|  | .n_voltages = MAX1586_V3_MAX_VSEL + 1, | 
|  | .owner = THIS_MODULE, | 
|  | }, | 
|  | { | 
|  | .name = "Output_V6", | 
|  | .id = MAX1586_V6, | 
|  | .ops = &max1586_v6_ops, | 
|  | .type = REGULATOR_VOLTAGE, | 
|  | .n_voltages = MAX1586_V6_MAX_VSEL + 1, | 
|  | .owner = THIS_MODULE, | 
|  | }, | 
|  | }; | 
|  |  | 
|  | static int __devinit max1586_pmic_probe(struct i2c_client *client, | 
|  | const struct i2c_device_id *i2c_id) | 
|  | { | 
|  | struct regulator_dev **rdev; | 
|  | struct max1586_platform_data *pdata = client->dev.platform_data; | 
|  | struct max1586_data *max1586; | 
|  | int i, id, ret = -ENOMEM; | 
|  |  | 
|  | max1586 = kzalloc(sizeof(struct max1586_data) + | 
|  | sizeof(struct regulator_dev *) * (MAX1586_V6 + 1), | 
|  | GFP_KERNEL); | 
|  | if (!max1586) | 
|  | goto out; | 
|  |  | 
|  | max1586->client = client; | 
|  |  | 
|  | if (!pdata->v3_gain) { | 
|  | ret = -EINVAL; | 
|  | goto out_unmap; | 
|  | } | 
|  | max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000; | 
|  | max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000; | 
|  |  | 
|  | rdev = max1586->rdev; | 
|  | for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) { | 
|  | id = pdata->subdevs[i].id; | 
|  | if (!pdata->subdevs[i].platform_data) | 
|  | continue; | 
|  | if (id < MAX1586_V3 || id > MAX1586_V6) { | 
|  | dev_err(&client->dev, "invalid regulator id %d\n", id); | 
|  | goto err; | 
|  | } | 
|  | rdev[i] = regulator_register(&max1586_reg[id], &client->dev, | 
|  | pdata->subdevs[i].platform_data, | 
|  | max1586); | 
|  | if (IS_ERR(rdev[i])) { | 
|  | ret = PTR_ERR(rdev[i]); | 
|  | dev_err(&client->dev, "failed to register %s\n", | 
|  | max1586_reg[id].name); | 
|  | goto err; | 
|  | } | 
|  | } | 
|  |  | 
|  | i2c_set_clientdata(client, max1586); | 
|  | dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n"); | 
|  | return 0; | 
|  |  | 
|  | err: | 
|  | while (--i >= 0) | 
|  | regulator_unregister(rdev[i]); | 
|  | out_unmap: | 
|  | kfree(max1586); | 
|  | out: | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static int __devexit max1586_pmic_remove(struct i2c_client *client) | 
|  | { | 
|  | struct max1586_data *max1586 = i2c_get_clientdata(client); | 
|  | int i; | 
|  |  | 
|  | for (i = 0; i <= MAX1586_V6; i++) | 
|  | if (max1586->rdev[i]) | 
|  | regulator_unregister(max1586->rdev[i]); | 
|  | kfree(max1586); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct i2c_device_id max1586_id[] = { | 
|  | { "max1586", 0 }, | 
|  | { } | 
|  | }; | 
|  | MODULE_DEVICE_TABLE(i2c, max1586_id); | 
|  |  | 
|  | static struct i2c_driver max1586_pmic_driver = { | 
|  | .probe = max1586_pmic_probe, | 
|  | .remove = __devexit_p(max1586_pmic_remove), | 
|  | .driver		= { | 
|  | .name	= "max1586", | 
|  | .owner	= THIS_MODULE, | 
|  | }, | 
|  | .id_table	= max1586_id, | 
|  | }; | 
|  |  | 
|  | static int __init max1586_pmic_init(void) | 
|  | { | 
|  | return i2c_add_driver(&max1586_pmic_driver); | 
|  | } | 
|  | subsys_initcall(max1586_pmic_init); | 
|  |  | 
|  | static void __exit max1586_pmic_exit(void) | 
|  | { | 
|  | i2c_del_driver(&max1586_pmic_driver); | 
|  | } | 
|  | module_exit(max1586_pmic_exit); | 
|  |  | 
|  | /* Module information */ | 
|  | MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver"); | 
|  | MODULE_AUTHOR("Robert Jarzmik"); | 
|  | MODULE_LICENSE("GPL"); |