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Commit 86d9884b authored by Roger Quadros's avatar Roger Quadros Committed by Liam Girdwood
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regulator: Add GPIO enable control to fixed voltage regulator driver 



Now fixed regulators that have their enable pin connected to a GPIO line
can use the fixed regulator driver for regulator enable/disable control.
The GPIO number and polarity information is passed through platform data.
GPIO enable control is achieved using gpiolib.

Signed-off-by: default avatarRoger Quadros <ext-roger.quadros@nokia.com>
Reviewed-by: default avatarPhilipp Zabel <philipp.zabel@gmail.com>
Reviewed-by: default avatarFelipe Balbi <felipe.balbi@nokia.com>
Acked-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: default avatarLiam Girdwood <lrg@slimlogic.co.uk>
parent a6576cff

drivers/regulator/fixed.c

+86 −2
Original line number Diff line number Diff line
@@ -5,6 +5,9 @@ 
 *

 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>

 *

 * Copyright (c) 2009 Nokia Corporation

 * Roger Quadros <ext-roger.quadros@nokia.com>

 *

 * 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
@@ -20,20 +23,45 @@ 
#include <linux/platform_device.h>

#include <linux/regulator/driver.h>

#include <linux/regulator/fixed.h>

#include <linux/gpio.h>



struct fixed_voltage_data {

	struct regulator_desc desc;

	struct regulator_dev *dev;

	int microvolts;

	int gpio;

	unsigned enable_high:1;

	unsigned is_enabled:1;

};



static int fixed_voltage_is_enabled(struct regulator_dev *dev)

{

	return 1;

	struct fixed_voltage_data *data = rdev_get_drvdata(dev);



	return data->is_enabled;

}



static int fixed_voltage_enable(struct regulator_dev *dev)

{

	struct fixed_voltage_data *data = rdev_get_drvdata(dev);



	if (gpio_is_valid(data->gpio)) {

		gpio_set_value_cansleep(data->gpio, data->enable_high);

		data->is_enabled = 1;

	}



	return 0;

}



static int fixed_voltage_disable(struct regulator_dev *dev)

{

	struct fixed_voltage_data *data = rdev_get_drvdata(dev);



	if (gpio_is_valid(data->gpio)) {

		gpio_set_value_cansleep(data->gpio, !data->enable_high);

		data->is_enabled = 0;

	}



	return 0;

}
@@ -58,6 +86,7 @@ static int fixed_voltage_list_voltage(struct regulator_dev *dev, 
static struct regulator_ops fixed_voltage_ops = {

	.is_enabled = fixed_voltage_is_enabled,

	.enable = fixed_voltage_enable,

	.disable = fixed_voltage_disable,

	.get_voltage = fixed_voltage_get_voltage,

	.list_voltage = fixed_voltage_list_voltage,

};
@@ -87,13 +116,62 @@ static int regulator_fixed_voltage_probe(struct platform_device *pdev) 
	drvdata->desc.n_voltages = 1;



	drvdata->microvolts = config->microvolts;

	drvdata->gpio = config->gpio;



	if (gpio_is_valid(config->gpio)) {

		drvdata->enable_high = config->enable_high;



		/* FIXME: Remove below print warning

		 *

		 * config->gpio must be set to -EINVAL by platform code if

		 * GPIO control is not required. However, early adopters

		 * not requiring GPIO control may forget to initialize

		 * config->gpio to -EINVAL. This will cause GPIO 0 to be used

		 * for GPIO control.

		 *

		 * This warning will be removed once there are a couple of users

		 * for this driver.

		 */

		if (!config->gpio)

			dev_warn(&pdev->dev,

				"using GPIO 0 for regulator enable control\n");



		ret = gpio_request(config->gpio, config->supply_name);

		if (ret) {

			dev_err(&pdev->dev,

			   "Could not obtain regulator enable GPIO %d: %d\n",

							config->gpio, ret);

			goto err_name;

		}



		/* set output direction without changing state

		 * to prevent glitch

		 */

		drvdata->is_enabled = config->enabled_at_boot;

		ret = drvdata->is_enabled ?

				config->enable_high : !config->enable_high;



		ret = gpio_direction_output(config->gpio, ret);

		if (ret) {

			dev_err(&pdev->dev,

			   "Could not configure regulator enable GPIO %d direction: %d\n",

							config->gpio, ret);

			goto err_gpio;

		}



	} else {

		/* Regulator without GPIO control is considered

		 * always enabled

		 */

		drvdata->is_enabled = 1;

	}



	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,

					  config->init_data, drvdata);

	if (IS_ERR(drvdata->dev)) {

		ret = PTR_ERR(drvdata->dev);

		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);

		goto err_name;

		goto err_gpio;

	}



	platform_set_drvdata(pdev, drvdata);
@@ -103,6 +181,9 @@ static int regulator_fixed_voltage_probe(struct platform_device *pdev) 


	return 0;



err_gpio:

	if (gpio_is_valid(config->gpio))

		gpio_free(config->gpio);

err_name:

	kfree(drvdata->desc.name);

err:
@@ -118,6 +199,9 @@ static int regulator_fixed_voltage_remove(struct platform_device *pdev) 
	kfree(drvdata->desc.name);

	kfree(drvdata);



	if (gpio_is_valid(drvdata->gpio))

		gpio_free(drvdata->gpio);



	return 0;

}

include/linux/regulator/fixed.h

+24 −0
Original line number Diff line number Diff line
@@ -5,6 +5,9 @@ 
 *

 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>

 *

 * Copyright (c) 2009 Nokia Corporation

 * Roger Quadros <ext-roger.quadros@nokia.com>

 *

 * 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
@@ -16,9 +19,30 @@ 


struct regulator_init_data;



/**

 * struct fixed_voltage_config - fixed_voltage_config structure

 * @supply_name:	Name of the regulator supply

 * @microvolts:		Output voltage of regulator

 * @gpio:		GPIO to use for enable control

 * 			set to -EINVAL if not used

 * @enable_high:	Polarity of enable GPIO

 *			1 = Active high, 0 = Active low

 * @enabled_at_boot:	Whether regulator has been enabled at

 * 			boot or not. 1 = Yes, 0 = No

 * 			This is used to keep the regulator at

 * 			the default state

 * @init_data:		regulator_init_data

 *

 * This structure contains fixed voltage regulator configuration

 * information that must be passed by platform code to the fixed

 * voltage regulator driver.

 */

struct fixed_voltage_config {

	const char *supply_name;

	int microvolts;

	int gpio;

	unsigned enable_high:1;

	unsigned enabled_at_boot:1;

	struct regulator_init_data *init_data;

};