/*
* 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>
#include <linux/of_device.h>
#include <linux/regulator/of_regulator.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;
unsigned int v3_curr_sel;
unsigned int v6_curr_sel;
};
/*
* 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 const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
/*
* 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_get_voltage_sel(struct regulator_dev *rdev)
{
struct max1586_data *max1586 = rdev_get_drvdata(rdev);
return max1586->v3_curr_sel;
}
static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
unsigned selector)
{
struct max1586_data *max1586 = rdev_get_drvdata(rdev);
struct i2c_client *client = max1586->client;
int ret;
u8 v3_prog;
dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
regulator_list_voltage_linear(rdev, selector) / 1000);
v3_prog = I2C_V3_SELECT | (u8) selector;
ret = i2c_smbus_write_byte(client, v3_prog);
if (ret)
return ret;
max1586->v3_curr_sel = selector;
return 0;
}
static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)
{
struct max1586_data *max1586 = rdev_get_drvdata(rdev);
return max1586->v6_curr_sel;
}
static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
unsigned int selector)
{
struct max1586_data *max1586 = rdev_get_drvdata(rdev);
struct i2c_client *client = max1586->client;
u8 v6_prog;
int ret;
dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
rdev->desc->volt_table[selector] / 1000);
v6_prog = I2C_V6_SELECT | (u8) selector;
ret = i2c_smbus_write_byte(client, v6_prog);
if (ret)
return ret;
max1586->v6_curr_sel = selector;
return 0;
}
/*
* 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 = {
.get_voltage_sel = max1586_v3_get_voltage_sel,
.set_voltage_sel = max1586_v3_set_voltage_sel,
.list_voltage = regulator_list_voltage_linear,
.map_voltage = regulator_map_voltage_linear,
};
static struct regulator_ops max1586_v6_ops = {
.get_voltage_sel = max1586_v6_get_voltage_sel,
.set_voltage_sel = max1586_v6_set_voltage_sel,
.list_voltage = regulator_list_voltage_table,
};
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,
.volt_table = v6_voltages_uv,
.owner = THIS_MODULE,
},
};
static int of_get_max1586_platform_data(struct device *dev,
struct max1586_platform_data *pdata)
{
struct max1586_subdev_data *sub;
struct of_regulator_match rmatch[ARRAY_SIZE(max1586_reg)] = { };
struct device_node *np = dev->of_node;
int i, matched;
if (of_property_read_u32(np, "v3-gain",
&pdata->v3_gain) < 0) {
dev_err(dev, "%s has no 'v3-gain' property\n", np->full_name);
return -EINVAL;
}
np = of_get_child_by_name(np, "regulators");
if (!np) {
dev_err(dev, "missing 'regulators' subnode in DT\n");
return -EINVAL;
}
for (i = 0; i < ARRAY_SIZE(rmatch); i++)
rmatch[i].name = max1586_reg[i].name;
matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));
of_node_put(np);
/*
* If matched is 0, ie. neither Output_V3 nor Output_V6 have been found,
* return 0, which signals the normal situation where no subregulator is
* available. This is normal because the max1586 doesn't provide any
* readback support, so the subregulators can't report any status
* anyway. If matched < 0, return the error.
*/
if (matched <= 0)
return matched;
pdata->subdevs = devm_kzalloc(dev, sizeof(struct max1586_subdev_data) *
matched, GFP_KERNEL);
if (!pdata->subdevs)
return -ENOMEM;
pdata->num_subdevs = matched;
sub = pdata->subdevs;
for (i = 0; i < matched; i++) {
sub->id = i;
sub->name = rmatch[i].of_node->name;
sub->platform_data = rmatch[i].init_data;
sub++;
}
return 0;
}
static const struct of_device_id max1586_of_match[] = {
{ .compatible = "maxim,max1586", },
{},
};
MODULE_DEVICE_TABLE(of, max1586_of_match);
static int max1586_pmic_probe(struct i2c_client *client,
const struct i2c_device_id *i2c_id)
{
struct max1586_platform_data *pdata, pdata_of;
struct regulator_config config = { };
struct max1586_data *max1586;
int i, id, ret;
const struct of_device_id *match;
pdata = dev_get_platdata(&client->dev);
if (client->dev.of_node && !pdata) {
match = of_match_device(of_match_ptr(max1586_of_match),
&client->dev);
if (!match) {
dev_err(&client->dev, "Error: No device match found\n");
return -ENODEV;
}
ret = of_get_max1586_platform_data(&client->dev, &pdata_of);
if (ret < 0)
return ret;
pdata = &pdata_of;
}
max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data),
GFP_KERNEL);
if (!max1586)
return -ENOMEM;
max1586->client = client;
if (!pdata->v3_gain)
return -EINVAL;
max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
/* Set curr_sel to default voltage on power-up */
max1586->v3_curr_sel = 24; /* 1.3V */
max1586->v6_curr_sel = 0;
for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
struct regulator_dev *rdev;
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);
return -EINVAL;
}
if (id == MAX1586_V3) {
max1586_reg[id].min_uV = max1586->min_uV;
max1586_reg[id].uV_step =
(max1586->max_uV - max1586->min_uV) /
MAX1586_V3_MAX_VSEL;
}
config.dev = &client->dev;
config.init_data = pdata->subdevs[i].platform_data;
config.driver_data = max1586;
rdev = devm_regulator_register(&client->dev,
&max1586_reg[id], &config);
if (IS_ERR(rdev)) {
dev_err(&client->dev, "failed to register %s\n",
max1586_reg[id].name);
return PTR_ERR(rdev);
}
}
i2c_set_clientdata(client, max1586);
dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
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,
.driver = {
.name = "max1586",
.of_match_table = of_match_ptr(max1586_of_match),
},
.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");