/*
* 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)
{
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 __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, 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 __devexit 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);
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");
