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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: Roger Quadros <ext-roger.quadros@nokia.com>
Reviewed-by: Philipp Zabel <philipp.zabel@gmail.com>
Reviewed-by: Felipe Balbi <felipe.balbi@nokia.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
This commit is contained in:
Roger Quadros 2009-08-06 19:37:29 +03:00 committed by Liam Girdwood
parent a6576cff18
commit 86d9884b6a
2 changed files with 110 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

88
drivers/regulator/fixed.c
View File

@ -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;
}

24
include/linux/regulator/fixed.h
View File

@ -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;
};