 2c043bcbf2
			
		
	
	
	2c043bcbf2
	
	
	
		
			
			With device tree support for regulators, its needed that the regulator_dev->dev device has the right of_node attached. To be able to do this add an additional parameter to the regulator_register() api, wherein the dt-adapted driver can then pass this additional info onto the regulator core. Signed-off-by: Rajendra Nayak <rnayak@ti.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
		
			
				
	
	
		
			364 lines
		
	
	
	
		
			9.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			364 lines
		
	
	
	
		
			9.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * max8952.c - Voltage and current regulation for the Maxim 8952
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|  *
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|  * Copyright (C) 2010 Samsung Electronics
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|  * MyungJoo Ham <myungjoo.ham@samsung.com>
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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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| 
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| #include <linux/module.h>
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| #include <linux/init.h>
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| #include <linux/i2c.h>
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| #include <linux/err.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/max8952.h>
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| #include <linux/gpio.h>
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| #include <linux/io.h>
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| #include <linux/slab.h>
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| 
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| /* Registers */
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| enum {
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| 	MAX8952_REG_MODE0,
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| 	MAX8952_REG_MODE1,
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| 	MAX8952_REG_MODE2,
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| 	MAX8952_REG_MODE3,
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| 	MAX8952_REG_CONTROL,
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| 	MAX8952_REG_SYNC,
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| 	MAX8952_REG_RAMP,
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| 	MAX8952_REG_CHIP_ID1,
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| 	MAX8952_REG_CHIP_ID2,
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| };
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| 
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| struct max8952_data {
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| 	struct i2c_client	*client;
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| 	struct device		*dev;
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| 	struct max8952_platform_data *pdata;
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| 	struct regulator_dev	*rdev;
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| 
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| 	bool vid0;
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| 	bool vid1;
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| 	bool en;
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| };
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| 
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| static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
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| {
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| 	int ret = i2c_smbus_read_byte_data(max8952->client, reg);
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| 	if (ret > 0)
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| 		ret &= 0xff;
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| 
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| 	return ret;
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| }
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| 
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| static int max8952_write_reg(struct max8952_data *max8952,
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| 		u8 reg, u8 value)
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| {
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| 	return i2c_smbus_write_byte_data(max8952->client, reg, value);
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| }
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| 
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| static int max8952_voltage(struct max8952_data *max8952, u8 mode)
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| {
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| 	return (max8952->pdata->dvs_mode[mode] * 10 + 770) * 1000;
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| }
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| 
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| static int max8952_list_voltage(struct regulator_dev *rdev,
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| 		unsigned int selector)
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| {
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| 	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
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| 
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| 	if (rdev_get_id(rdev) != 0)
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| 		return -EINVAL;
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| 
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| 	return max8952_voltage(max8952, selector);
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| }
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| 
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| static int max8952_is_enabled(struct regulator_dev *rdev)
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| {
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| 	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
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| 	return max8952->en;
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| }
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| 
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| static int max8952_enable(struct regulator_dev *rdev)
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| {
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| 	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
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| 
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| 	/* If not valid, assume "ALWAYS_HIGH" */
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| 	if (gpio_is_valid(max8952->pdata->gpio_en))
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| 		gpio_set_value(max8952->pdata->gpio_en, 1);
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| 
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| 	max8952->en = true;
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| 	return 0;
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| }
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| 
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| static int max8952_disable(struct regulator_dev *rdev)
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| {
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| 	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
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| 
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| 	/* If not valid, assume "ALWAYS_HIGH" -> not permitted */
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| 	if (gpio_is_valid(max8952->pdata->gpio_en))
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| 		gpio_set_value(max8952->pdata->gpio_en, 0);
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| 	else
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| 		return -EPERM;
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| 
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| 	max8952->en = false;
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| 	return 0;
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| }
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| 
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| static int max8952_get_voltage(struct regulator_dev *rdev)
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| {
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| 	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
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| 	u8 vid = 0;
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| 
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| 	if (max8952->vid0)
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| 		vid += 1;
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| 	if (max8952->vid1)
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| 		vid += 2;
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| 
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| 	return max8952_voltage(max8952, vid);
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| }
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| 
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| static int max8952_set_voltage(struct regulator_dev *rdev,
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| 			       int min_uV, int max_uV, unsigned *selector)
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| {
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| 	struct max8952_data *max8952 = rdev_get_drvdata(rdev);
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| 	s8 vid = -1, i;
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| 
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| 	if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
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| 			!gpio_is_valid(max8952->pdata->gpio_vid1)) {
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| 		/* DVS not supported */
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| 		return -EPERM;
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| 	}
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| 
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| 	for (i = 0; i < MAX8952_NUM_DVS_MODE; i++) {
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| 		int volt = max8952_voltage(max8952, i);
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| 
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| 		/* Set the voltage as low as possible within the range */
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| 		if (volt <= max_uV && volt >= min_uV)
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| 			if (vid == -1 || max8952_voltage(max8952, vid) > volt)
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| 				vid = i;
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| 	}
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| 
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| 	if (vid >= 0 && vid < MAX8952_NUM_DVS_MODE) {
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| 		max8952->vid0 = (vid % 2 == 1);
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| 		max8952->vid1 = (((vid >> 1) % 2) == 1);
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| 		*selector = vid;
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| 		gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
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| 		gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
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| 	} else
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| 		return -EINVAL;
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| 
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| 	return 0;
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| }
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| 
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| static struct regulator_ops max8952_ops = {
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| 	.list_voltage		= max8952_list_voltage,
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| 	.is_enabled		= max8952_is_enabled,
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| 	.enable			= max8952_enable,
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| 	.disable		= max8952_disable,
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| 	.get_voltage		= max8952_get_voltage,
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| 	.set_voltage		= max8952_set_voltage,
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| 	.set_suspend_disable	= max8952_disable,
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| };
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| 
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| static struct regulator_desc regulator = {
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| 	.name		= "MAX8952_VOUT",
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| 	.id		= 0,
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| 	.n_voltages	= MAX8952_NUM_DVS_MODE,
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| 	.ops		= &max8952_ops,
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| 	.type		= REGULATOR_VOLTAGE,
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| 	.owner		= THIS_MODULE,
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| };
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| 
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| static int __devinit max8952_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 i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
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| 	struct max8952_platform_data *pdata = client->dev.platform_data;
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| 	struct max8952_data *max8952;
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| 
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| 	int ret = 0, err = 0;
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| 
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| 	if (!pdata) {
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| 		dev_err(&client->dev, "Require the platform data\n");
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| 		return -EINVAL;
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| 	}
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| 
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| 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
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| 		return -EIO;
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| 
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| 	max8952 = kzalloc(sizeof(struct max8952_data), GFP_KERNEL);
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| 	if (!max8952)
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| 		return -ENOMEM;
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| 
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| 	max8952->client = client;
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| 	max8952->dev = &client->dev;
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| 	max8952->pdata = pdata;
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| 
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| 	max8952->rdev = regulator_register(®ulator, max8952->dev,
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| 			&pdata->reg_data, max8952, NULL);
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| 
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| 	if (IS_ERR(max8952->rdev)) {
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| 		ret = PTR_ERR(max8952->rdev);
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| 		dev_err(max8952->dev, "regulator init failed (%d)\n", ret);
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| 		goto err_reg;
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| 	}
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| 
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| 	max8952->en = !!(pdata->reg_data.constraints.boot_on);
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| 	max8952->vid0 = (pdata->default_mode % 2) == 1;
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| 	max8952->vid1 = ((pdata->default_mode >> 1) % 2) == 1;
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| 
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| 	if (gpio_is_valid(pdata->gpio_en)) {
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| 		if (!gpio_request(pdata->gpio_en, "MAX8952 EN"))
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| 			gpio_direction_output(pdata->gpio_en, max8952->en);
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| 		else
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| 			err = 1;
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| 	} else
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| 		err = 2;
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| 
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| 	if (err) {
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| 		dev_info(max8952->dev, "EN gpio invalid: assume that EN"
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| 				"is always High\n");
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| 		max8952->en = 1;
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| 		pdata->gpio_en = -1; /* Mark invalid */
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| 	}
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| 
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| 	err = 0;
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| 
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| 	if (gpio_is_valid(pdata->gpio_vid0) &&
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| 			gpio_is_valid(pdata->gpio_vid1)) {
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| 		if (!gpio_request(pdata->gpio_vid0, "MAX8952 VID0"))
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| 			gpio_direction_output(pdata->gpio_vid0,
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| 					(pdata->default_mode) % 2);
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| 		else
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| 			err = 1;
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| 
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| 		if (!gpio_request(pdata->gpio_vid1, "MAX8952 VID1"))
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| 			gpio_direction_output(pdata->gpio_vid1,
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| 				(pdata->default_mode >> 1) % 2);
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| 		else {
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| 			if (!err)
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| 				gpio_free(pdata->gpio_vid0);
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| 			err = 2;
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| 		}
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| 
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| 	} else
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| 		err = 3;
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| 
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| 	if (err) {
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| 		dev_warn(max8952->dev, "VID0/1 gpio invalid: "
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| 				"DVS not available.\n");
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| 		max8952->vid0 = 0;
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| 		max8952->vid1 = 0;
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| 		/* Mark invalid */
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| 		pdata->gpio_vid0 = -1;
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| 		pdata->gpio_vid1 = -1;
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| 
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| 		/* Disable Pulldown of EN only */
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| 		max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
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| 
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| 		dev_err(max8952->dev, "DVS modes disabled because VID0 and VID1"
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| 				" do not have proper controls.\n");
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| 	} else {
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| 		/*
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| 		 * Disable Pulldown on EN, VID0, VID1 to reduce
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| 		 * leakage current of MAX8952 assuming that MAX8952
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| 		 * is turned on (EN==1). Note that without having VID0/1
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| 		 * properly connected, turning pulldown off can be
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| 		 * problematic. Thus, turn this off only when they are
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| 		 * controllable by GPIO.
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| 		 */
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| 		max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
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| 	}
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| 
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| 	max8952_write_reg(max8952, MAX8952_REG_MODE0,
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| 			(max8952_read_reg(max8952,
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| 					  MAX8952_REG_MODE0) & 0xC0) |
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| 			(pdata->dvs_mode[0] & 0x3F));
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| 	max8952_write_reg(max8952, MAX8952_REG_MODE1,
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| 			(max8952_read_reg(max8952,
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| 					  MAX8952_REG_MODE1) & 0xC0) |
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| 			(pdata->dvs_mode[1] & 0x3F));
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| 	max8952_write_reg(max8952, MAX8952_REG_MODE2,
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| 			(max8952_read_reg(max8952,
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| 					  MAX8952_REG_MODE2) & 0xC0) |
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| 			(pdata->dvs_mode[2] & 0x3F));
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| 	max8952_write_reg(max8952, MAX8952_REG_MODE3,
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| 			(max8952_read_reg(max8952,
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| 					  MAX8952_REG_MODE3) & 0xC0) |
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| 			(pdata->dvs_mode[3] & 0x3F));
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| 
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| 	max8952_write_reg(max8952, MAX8952_REG_SYNC,
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| 			(max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
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| 			((pdata->sync_freq & 0x3) << 6));
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| 	max8952_write_reg(max8952, MAX8952_REG_RAMP,
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| 			(max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
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| 			((pdata->ramp_speed & 0x7) << 5));
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| 
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| 	i2c_set_clientdata(client, max8952);
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| 
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| 	return 0;
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| 
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| err_reg:
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| 	kfree(max8952);
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| 	return ret;
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| }
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| 
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| static int __devexit max8952_pmic_remove(struct i2c_client *client)
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| {
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| 	struct max8952_data *max8952 = i2c_get_clientdata(client);
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| 	struct max8952_platform_data *pdata = max8952->pdata;
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| 	struct regulator_dev *rdev = max8952->rdev;
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| 
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| 	regulator_unregister(rdev);
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| 
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| 	gpio_free(pdata->gpio_vid0);
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| 	gpio_free(pdata->gpio_vid1);
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| 	gpio_free(pdata->gpio_en);
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| 
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| 	kfree(max8952);
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| 	return 0;
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| }
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| 
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| static const struct i2c_device_id max8952_ids[] = {
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| 	{ "max8952", 0 },
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| 	{ },
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| };
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| MODULE_DEVICE_TABLE(i2c, max8952_ids);
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| 
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| static struct i2c_driver max8952_pmic_driver = {
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| 	.probe		= max8952_pmic_probe,
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| 	.remove		= __devexit_p(max8952_pmic_remove),
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| 	.driver		= {
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| 		.name	= "max8952",
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| 	},
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| 	.id_table	= max8952_ids,
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| };
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| 
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| static int __init max8952_pmic_init(void)
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| {
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| 	return i2c_add_driver(&max8952_pmic_driver);
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| }
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| subsys_initcall(max8952_pmic_init);
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| 
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| static void __exit max8952_pmic_exit(void)
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| {
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| 	i2c_del_driver(&max8952_pmic_driver);
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| }
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| module_exit(max8952_pmic_exit);
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| 
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| MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
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| MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
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| MODULE_LICENSE("GPL");
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