linux-imx

/*

 * 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;