/* * 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/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) { struct max1586_data *max1586 = rdev_get_drvdata(rdev); struct i2c_client *client = max1586->client; unsigned range_uV = max1586->max_uV - max1586->min_uV; unsigned selector; 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) { struct i2c_client *client = rdev_get_drvdata(rdev); unsigned selector; 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 >= 3000000) selector = 3; if (min_uV < 3000000) selector = 2; if (min_uV < 2500000) selector = 1; if (min_uV < 1800000) selector = 0; 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 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, rdev); 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 max1586_pmic_remove(struct i2c_client *client) { struct regulator_dev **rdev = i2c_get_clientdata(client); int i; for (i = 0; i <= MAX1586_V6; i++) if (rdev[i]) regulator_unregister(rdev[i]); kfree(rdev); i2c_set_clientdata(client, NULL); 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 = max1586_pmic_remove, .driver = { .name = "max1586", }, .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");