283 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			283 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * max1586.c  --  Voltage and current regulation for the Maxim 1586
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 *
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 * Copyright (C) 2008 Robert Jarzmik
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation; either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 */
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#include <linux/module.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/driver.h>
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#include <linux/regulator/max1586.h>
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#define MAX1586_V3_MAX_VSEL 31
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#define MAX1586_V6_MAX_VSEL 3
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#define MAX1586_V3_MIN_UV   700000
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#define MAX1586_V3_MAX_UV  1475000
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#define MAX1586_V6_MIN_UV        0
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#define MAX1586_V6_MAX_UV  3000000
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#define I2C_V3_SELECT (0 << 5)
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#define I2C_V6_SELECT (1 << 5)
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struct max1586_data {
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	struct i2c_client *client;
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	/* min/max V3 voltage */
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	unsigned int min_uV;
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	unsigned int max_uV;
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	struct regulator_dev *rdev[0];
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};
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/*
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 * V3 voltage
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 * On I2C bus, sending a "x" byte to the max1586 means :
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 *   set V3 to 0.700V + (x & 0x1f) * 0.025V
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 * This voltage can be increased by external resistors
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 * R24 and R25=100kOhm as described in the data sheet.
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 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
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 */
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static int max1586_v3_calc_voltage(struct max1586_data *max1586,
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	unsigned selector)
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{
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	unsigned range_uV = max1586->max_uV - max1586->min_uV;
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	return max1586->min_uV + (selector * range_uV / MAX1586_V3_MAX_VSEL);
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}
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static int max1586_v3_set(struct regulator_dev *rdev, int min_uV, int max_uV)
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{
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	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
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	struct i2c_client *client = max1586->client;
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	unsigned range_uV = max1586->max_uV - max1586->min_uV;
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	unsigned selector;
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	u8 v3_prog;
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	if (min_uV > max1586->max_uV || max_uV < max1586->min_uV)
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		return -EINVAL;
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	if (min_uV < max1586->min_uV)
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		min_uV = max1586->min_uV;
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	selector = ((min_uV - max1586->min_uV) * MAX1586_V3_MAX_VSEL +
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			range_uV - 1) / range_uV;
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	if (max1586_v3_calc_voltage(max1586, selector) > max_uV)
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		return -EINVAL;
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	dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
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		max1586_v3_calc_voltage(max1586, selector) / 1000);
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	v3_prog = I2C_V3_SELECT | (u8) selector;
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	return i2c_smbus_write_byte(client, v3_prog);
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}
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static int max1586_v3_list(struct regulator_dev *rdev, unsigned selector)
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{
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	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
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	if (selector > MAX1586_V3_MAX_VSEL)
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		return -EINVAL;
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	return max1586_v3_calc_voltage(max1586, selector);
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}
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/*
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 * V6 voltage
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 * On I2C bus, sending a "x" byte to the max1586 means :
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 *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
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 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
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 */
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static int max1586_v6_calc_voltage(unsigned selector)
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{
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	static int voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
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	return voltages_uv[selector];
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}
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static int max1586_v6_set(struct regulator_dev *rdev, int min_uV, int max_uV)
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{
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	struct i2c_client *client = rdev_get_drvdata(rdev);
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	unsigned selector;
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	u8 v6_prog;
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	if (min_uV < MAX1586_V6_MIN_UV || min_uV > MAX1586_V6_MAX_UV)
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		return -EINVAL;
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	if (max_uV < MAX1586_V6_MIN_UV || max_uV > MAX1586_V6_MAX_UV)
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		return -EINVAL;
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	if (min_uV >= 3000000)
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		selector = 3;
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	if (min_uV < 3000000)
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		selector = 2;
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	if (min_uV < 2500000)
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		selector = 1;
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	if (min_uV < 1800000)
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		selector = 0;
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	if (max1586_v6_calc_voltage(selector) > max_uV)
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		return -EINVAL;
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	dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
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		max1586_v6_calc_voltage(selector) / 1000);
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	v6_prog = I2C_V6_SELECT | (u8) selector;
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	return i2c_smbus_write_byte(client, v6_prog);
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}
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static int max1586_v6_list(struct regulator_dev *rdev, unsigned selector)
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{
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	if (selector > MAX1586_V6_MAX_VSEL)
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		return -EINVAL;
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	return max1586_v6_calc_voltage(selector);
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}
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/*
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 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
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 * the set up value.
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 */
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static struct regulator_ops max1586_v3_ops = {
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	.set_voltage = max1586_v3_set,
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	.list_voltage = max1586_v3_list,
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};
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static struct regulator_ops max1586_v6_ops = {
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	.set_voltage = max1586_v6_set,
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	.list_voltage = max1586_v6_list,
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};
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static struct regulator_desc max1586_reg[] = {
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	{
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		.name = "Output_V3",
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		.id = MAX1586_V3,
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		.ops = &max1586_v3_ops,
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		.type = REGULATOR_VOLTAGE,
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		.n_voltages = MAX1586_V3_MAX_VSEL + 1,
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		.owner = THIS_MODULE,
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	},
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	{
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		.name = "Output_V6",
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		.id = MAX1586_V6,
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		.ops = &max1586_v6_ops,
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		.type = REGULATOR_VOLTAGE,
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		.n_voltages = MAX1586_V6_MAX_VSEL + 1,
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		.owner = THIS_MODULE,
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	},
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};
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static int max1586_pmic_probe(struct i2c_client *client,
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			      const struct i2c_device_id *i2c_id)
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{
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	struct regulator_dev **rdev;
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	struct max1586_platform_data *pdata = client->dev.platform_data;
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	struct max1586_data *max1586;
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	int i, id, ret = -ENOMEM;
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	max1586 = kzalloc(sizeof(struct max1586_data) +
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			sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
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			GFP_KERNEL);
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	if (!max1586)
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		goto out;
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	max1586->client = client;
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	if (!pdata->v3_gain) {
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		ret = -EINVAL;
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		goto out_unmap;
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	}
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	max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
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	max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
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	rdev = max1586->rdev;
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	for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
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		id = pdata->subdevs[i].id;
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		if (!pdata->subdevs[i].platform_data)
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			continue;
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		if (id < MAX1586_V3 || id > MAX1586_V6) {
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			dev_err(&client->dev, "invalid regulator id %d\n", id);
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			goto err;
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		}
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		rdev[i] = regulator_register(&max1586_reg[id], &client->dev,
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					     pdata->subdevs[i].platform_data,
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					     max1586);
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		if (IS_ERR(rdev[i])) {
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			ret = PTR_ERR(rdev[i]);
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			dev_err(&client->dev, "failed to register %s\n",
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				max1586_reg[id].name);
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			goto err;
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		}
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	}
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	i2c_set_clientdata(client, rdev);
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	dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
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	return 0;
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err:
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	while (--i >= 0)
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		regulator_unregister(rdev[i]);
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out_unmap:
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	kfree(max1586);
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out:
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	return ret;
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}
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static int max1586_pmic_remove(struct i2c_client *client)
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{
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	struct regulator_dev **rdev = i2c_get_clientdata(client);
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	int i;
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	for (i = 0; i <= MAX1586_V6; i++)
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		if (rdev[i])
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			regulator_unregister(rdev[i]);
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	kfree(rdev);
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	i2c_set_clientdata(client, NULL);
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	return 0;
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}
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static const struct i2c_device_id max1586_id[] = {
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	{ "max1586", 0 },
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	{ }
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};
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MODULE_DEVICE_TABLE(i2c, max1586_id);
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static struct i2c_driver max1586_pmic_driver = {
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	.probe = max1586_pmic_probe,
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	.remove = max1586_pmic_remove,
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	.driver		= {
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		.name	= "max1586",
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	},
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	.id_table	= max1586_id,
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};
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static int __init max1586_pmic_init(void)
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{
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	return i2c_add_driver(&max1586_pmic_driver);
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}
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subsys_initcall(max1586_pmic_init);
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static void __exit max1586_pmic_exit(void)
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{
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	i2c_del_driver(&max1586_pmic_driver);
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}
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module_exit(max1586_pmic_exit);
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/* Module information */
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MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
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MODULE_AUTHOR("Robert Jarzmik");
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MODULE_LICENSE("GPL");
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