diff options
Diffstat (limited to 'drivers/regulator/max1586.c')
| -rw-r--r-- | drivers/regulator/max1586.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/drivers/regulator/max1586.c b/drivers/regulator/max1586.c new file mode 100644 index 00000000..282d2ee0 --- /dev/null +++ b/drivers/regulator/max1586.c @@ -0,0 +1,283 @@ +/* + * 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 = DIV_ROUND_UP((min_uV - max1586->min_uV) * + MAX1586_V3_MAX_VSEL, 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, NULL); + 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"); |