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linux/drivers/regulator/wm8994-regulator.c
Joonyoung Shim c4604e49c1 regulator: Default GPIO controlled WM8994 regulators to disabled 
This ensures that if the GPIO was not enabled prior to the driver
starting the regulator API will insert the required powerup ramp
delay when it enables the regulator.  The gpiolib API does not
provide this information.

[Rewrote changelog to describe the actual change -- broonie.]

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
2010-08-11 11:38:02 +01:00

307 lines
7.1 KiB
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/*
* wm8994-regulator.c -- Regulator driver for the WM8994
*
* Copyright 2009 Wolfson Microelectronics PLC.
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.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 License, or (at your
* option) any later version.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/mfd/wm8994/core.h>
#include <linux/mfd/wm8994/registers.h>
#include <linux/mfd/wm8994/pdata.h>
struct wm8994_ldo {
int enable;
bool is_enabled;
struct regulator_dev *regulator;
struct wm8994 *wm8994;
};
#define WM8994_LDO1_MAX_SELECTOR 0x7
#define WM8994_LDO2_MAX_SELECTOR 0x3
static int wm8994_ldo_enable(struct regulator_dev *rdev)
{
struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
/* If we have no soft control assume that the LDO is always enabled. */
if (!ldo->enable)
return 0;
gpio_set_value(ldo->enable, 1);
ldo->is_enabled = true;
return 0;
}
static int wm8994_ldo_disable(struct regulator_dev *rdev)
{
struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
/* If we have no soft control assume that the LDO is always enabled. */
if (!ldo->enable)
return -EINVAL;
gpio_set_value(ldo->enable, 0);
ldo->is_enabled = false;
return 0;
}
static int wm8994_ldo_is_enabled(struct regulator_dev *rdev)
{
struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
return ldo->is_enabled;
}
static int wm8994_ldo_enable_time(struct regulator_dev *rdev)
{
/* 3ms is fairly conservative but this shouldn't be too performance
* critical; can be tweaked per-system if required. */
return 3000;
}
static int wm8994_ldo1_list_voltage(struct regulator_dev *rdev,
unsigned int selector)
{
if (selector > WM8994_LDO1_MAX_SELECTOR)
return -EINVAL;
return (selector * 100000) + 2400000;
}
static int wm8994_ldo1_get_voltage(struct regulator_dev *rdev)
{
struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
int val;
val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_1);
if (val < 0)
return val;
val = (val & WM8994_LDO1_VSEL_MASK) >> WM8994_LDO1_VSEL_SHIFT;
return wm8994_ldo1_list_voltage(rdev, val);
}
static int wm8994_ldo1_set_voltage(struct regulator_dev *rdev,
int min_uV, int max_uV)
{
struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
int selector, v;
selector = (min_uV - 2400000) / 100000;
v = wm8994_ldo1_list_voltage(rdev, selector);
if (v < 0 || v > max_uV)
return -EINVAL;
selector <<= WM8994_LDO1_VSEL_SHIFT;
return wm8994_set_bits(ldo->wm8994, WM8994_LDO_1,
WM8994_LDO1_VSEL_MASK, selector);
}
static struct regulator_ops wm8994_ldo1_ops = {
.enable = wm8994_ldo_enable,
.disable = wm8994_ldo_disable,
.is_enabled = wm8994_ldo_is_enabled,
.enable_time = wm8994_ldo_enable_time,
.list_voltage = wm8994_ldo1_list_voltage,
.get_voltage = wm8994_ldo1_get_voltage,
.set_voltage = wm8994_ldo1_set_voltage,
};
static int wm8994_ldo2_list_voltage(struct regulator_dev *rdev,
unsigned int selector)
{
if (selector > WM8994_LDO2_MAX_SELECTOR)
return -EINVAL;
return (selector * 100000) + 900000;
}
static int wm8994_ldo2_get_voltage(struct regulator_dev *rdev)
{
struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
int val;
val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_2);
if (val < 0)
return val;
val = (val & WM8994_LDO2_VSEL_MASK) >> WM8994_LDO2_VSEL_SHIFT;
return wm8994_ldo2_list_voltage(rdev, val);
}
static int wm8994_ldo2_set_voltage(struct regulator_dev *rdev,
int min_uV, int max_uV)
{
struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
int selector, v;
selector = (min_uV - 900000) / 100000;
v = wm8994_ldo2_list_voltage(rdev, selector);
if (v < 0 || v > max_uV)
return -EINVAL;
selector <<= WM8994_LDO2_VSEL_SHIFT;
return wm8994_set_bits(ldo->wm8994, WM8994_LDO_2,
WM8994_LDO2_VSEL_MASK, selector);
}
static struct regulator_ops wm8994_ldo2_ops = {
.enable = wm8994_ldo_enable,
.disable = wm8994_ldo_disable,
.is_enabled = wm8994_ldo_is_enabled,
.enable_time = wm8994_ldo_enable_time,
.list_voltage = wm8994_ldo2_list_voltage,
.get_voltage = wm8994_ldo2_get_voltage,
.set_voltage = wm8994_ldo2_set_voltage,
};
static struct regulator_desc wm8994_ldo_desc[] = {
{
.name = "LDO1",
.id = 1,
.type = REGULATOR_VOLTAGE,
.n_voltages = WM8994_LDO1_MAX_SELECTOR + 1,
.ops = &wm8994_ldo1_ops,
.owner = THIS_MODULE,
},
{
.name = "LDO2",
.id = 2,
.type = REGULATOR_VOLTAGE,
.n_voltages = WM8994_LDO2_MAX_SELECTOR + 1,
.ops = &wm8994_ldo2_ops,
.owner = THIS_MODULE,
},
};
static __devinit int wm8994_ldo_probe(struct platform_device *pdev)
{
struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
struct wm8994_pdata *pdata = wm8994->dev->platform_data;
int id = pdev->id % ARRAY_SIZE(pdata->ldo);
struct wm8994_ldo *ldo;
int ret;
dev_dbg(&pdev->dev, "Probing LDO%d\n", id + 1);
if (!pdata)
return -ENODEV;
ldo = kzalloc(sizeof(struct wm8994_ldo), GFP_KERNEL);
if (ldo == NULL) {
dev_err(&pdev->dev, "Unable to allocate private data\n");
return -ENOMEM;
}
ldo->wm8994 = wm8994;
if (pdata->ldo[id].enable && gpio_is_valid(pdata->ldo[id].enable)) {
ldo->enable = pdata->ldo[id].enable;
ret = gpio_request(ldo->enable, "WM8994 LDO enable");
if (ret < 0) {
dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n",
ret);
goto err;
}
ret = gpio_direction_output(ldo->enable, ldo->is_enabled);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to set GPIO up: %d\n",
ret);
goto err_gpio;
}
} else
ldo->is_enabled = true;
ldo->regulator = regulator_register(&wm8994_ldo_desc[id], &pdev->dev,
pdata->ldo[id].init_data, ldo);
if (IS_ERR(ldo->regulator)) {
ret = PTR_ERR(ldo->regulator);
dev_err(wm8994->dev, "Failed to register LDO%d: %d\n",
id + 1, ret);
goto err_gpio;
}
platform_set_drvdata(pdev, ldo);
return 0;
err_gpio:
if (gpio_is_valid(ldo->enable))
gpio_free(ldo->enable);
err:
kfree(ldo);
return ret;
}
static __devexit int wm8994_ldo_remove(struct platform_device *pdev)
{
struct wm8994_ldo *ldo = platform_get_drvdata(pdev);
platform_set_drvdata(pdev, NULL);
regulator_unregister(ldo->regulator);
if (gpio_is_valid(ldo->enable))
gpio_free(ldo->enable);
kfree(ldo);
return 0;
}
static struct platform_driver wm8994_ldo_driver = {
.probe = wm8994_ldo_probe,
.remove = __devexit_p(wm8994_ldo_remove),
.driver = {
.name = "wm8994-ldo",
.owner = THIS_MODULE,
},
};
static int __init wm8994_ldo_init(void)
{
int ret;
ret = platform_driver_register(&wm8994_ldo_driver);
if (ret != 0)
pr_err("Failed to register Wm8994 GP LDO driver: %d\n", ret);
return ret;
}
subsys_initcall(wm8994_ldo_init);
static void __exit wm8994_ldo_exit(void)
{
platform_driver_unregister(&wm8994_ldo_driver);
}
module_exit(wm8994_ldo_exit);
/* Module information */
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("WM8994 LDO driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm8994-ldo");
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