Commit d4cc6a2e authored by Antonio Ospite's avatar Antonio Ospite Committed by Richard Purdie

leds: Add LED class driver for regulator driven LEDs.

This driver provides an interface for controlling LEDs (or vibrators)
connected to PMICs for which there is a regulator framework driver.

This driver can be used, for instance, to control vibrator on all Motorola EZX
phones using the pcap-regulator driver services.
Signed-off-by: default avatarAntonio Ospite <ospite@studenti.unina.it>
Reviewed-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: default avatarRichard Purdie <rpurdie@linux.intel.com>
parent 3c0f6e1e
......@@ -229,6 +229,12 @@ config LEDS_PWM
help
This option enables support for pwm driven LEDs
config LEDS_REGULATOR
tristate "REGULATOR driven LED support"
depends on LEDS_CLASS && REGULATOR
help
This option enables support for regulator driven LEDs.
config LEDS_BD2802
tristate "LED driver for BD2802 RGB LED"
depends on LEDS_CLASS && I2C
......
......@@ -29,6 +29,7 @@ obj-$(CONFIG_LEDS_DA903X) += leds-da903x.o
obj-$(CONFIG_LEDS_WM831X_STATUS) += leds-wm831x-status.o
obj-$(CONFIG_LEDS_WM8350) += leds-wm8350.o
obj-$(CONFIG_LEDS_PWM) += leds-pwm.o
obj-$(CONFIG_LEDS_REGULATOR) += leds-regulator.o
obj-$(CONFIG_LEDS_INTEL_SS4200) += leds-ss4200.o
obj-$(CONFIG_LEDS_LT3593) += leds-lt3593.o
obj-$(CONFIG_LEDS_ADP5520) += leds-adp5520.o
......
/*
* leds-regulator.c - LED class driver for regulator driven LEDs.
*
* Copyright (C) 2009 Antonio Ospite <ospite@studenti.unina.it>
*
* Inspired by leds-wm8350 driver.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/err.h>
#include <linux/workqueue.h>
#include <linux/leds.h>
#include <linux/leds-regulator.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#define to_regulator_led(led_cdev) \
container_of(led_cdev, struct regulator_led, cdev)
struct regulator_led {
struct led_classdev cdev;
enum led_brightness value;
int enabled;
struct mutex mutex;
struct work_struct work;
struct regulator *vcc;
};
static inline int led_regulator_get_max_brightness(struct regulator *supply)
{
int ret;
int voltage = regulator_list_voltage(supply, 0);
if (voltage <= 0)
return 1;
/* even if regulator can't change voltages,
* we still assume it can change status
* and the LED can be turned on and off.
*/
ret = regulator_set_voltage(supply, voltage, voltage);
if (ret < 0)
return 1;
return regulator_count_voltages(supply);
}
static int led_regulator_get_voltage(struct regulator *supply,
enum led_brightness brightness)
{
if (brightness == 0)
return -EINVAL;
return regulator_list_voltage(supply, brightness - 1);
}
static void regulator_led_enable(struct regulator_led *led)
{
int ret;
if (led->enabled)
return;
ret = regulator_enable(led->vcc);
if (ret != 0) {
dev_err(led->cdev.dev, "Failed to enable vcc: %d\n", ret);
return;
}
led->enabled = 1;
}
static void regulator_led_disable(struct regulator_led *led)
{
int ret;
if (!led->enabled)
return;
ret = regulator_disable(led->vcc);
if (ret != 0) {
dev_err(led->cdev.dev, "Failed to disable vcc: %d\n", ret);
return;
}
led->enabled = 0;
}
static void regulator_led_set_value(struct regulator_led *led)
{
int voltage;
int ret;
mutex_lock(&led->mutex);
if (led->value == LED_OFF) {
regulator_led_disable(led);
goto out;
}
if (led->cdev.max_brightness > 1) {
voltage = led_regulator_get_voltage(led->vcc, led->value);
dev_dbg(led->cdev.dev, "brightness: %d voltage: %d\n",
led->value, voltage);
ret = regulator_set_voltage(led->vcc, voltage, voltage);
if (ret != 0)
dev_err(led->cdev.dev, "Failed to set voltage %d: %d\n",
voltage, ret);
}
regulator_led_enable(led);
out:
mutex_unlock(&led->mutex);
}
static void led_work(struct work_struct *work)
{
struct regulator_led *led;
led = container_of(work, struct regulator_led, work);
regulator_led_set_value(led);
}
static void regulator_led_brightness_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct regulator_led *led = to_regulator_led(led_cdev);
led->value = value;
schedule_work(&led->work);
}
static int __devinit regulator_led_probe(struct platform_device *pdev)
{
struct led_regulator_platform_data *pdata = pdev->dev.platform_data;
struct regulator_led *led;
struct regulator *vcc;
int ret = 0;
if (pdata == NULL) {
dev_err(&pdev->dev, "no platform data\n");
return -ENODEV;
}
vcc = regulator_get_exclusive(&pdev->dev, "vled");
if (IS_ERR(vcc)) {
dev_err(&pdev->dev, "Cannot get vcc for %s\n", pdata->name);
return PTR_ERR(vcc);
}
led = kzalloc(sizeof(*led), GFP_KERNEL);
if (led == NULL) {
ret = -ENOMEM;
goto err_vcc;
}
led->cdev.max_brightness = led_regulator_get_max_brightness(vcc);
if (pdata->brightness > led->cdev.max_brightness) {
dev_err(&pdev->dev, "Invalid default brightness %d\n",
pdata->brightness);
ret = -EINVAL;
goto err_led;
}
led->value = pdata->brightness;
led->cdev.brightness_set = regulator_led_brightness_set;
led->cdev.name = pdata->name;
led->cdev.flags |= LED_CORE_SUSPENDRESUME;
led->vcc = vcc;
mutex_init(&led->mutex);
INIT_WORK(&led->work, led_work);
platform_set_drvdata(pdev, led);
ret = led_classdev_register(&pdev->dev, &led->cdev);
if (ret < 0) {
cancel_work_sync(&led->work);
goto err_led;
}
/* to expose the default value to userspace */
led->cdev.brightness = led->value;
/* Set the default led status */
regulator_led_set_value(led);
return 0;
err_led:
kfree(led);
err_vcc:
regulator_put(vcc);
return ret;
}
static int __devexit regulator_led_remove(struct platform_device *pdev)
{
struct regulator_led *led = platform_get_drvdata(pdev);
led_classdev_unregister(&led->cdev);
cancel_work_sync(&led->work);
regulator_led_disable(led);
regulator_put(led->vcc);
kfree(led);
return 0;
}
static struct platform_driver regulator_led_driver = {
.driver = {
.name = "leds-regulator",
.owner = THIS_MODULE,
},
.probe = regulator_led_probe,
.remove = __devexit_p(regulator_led_remove),
};
static int __init regulator_led_init(void)
{
return platform_driver_register(&regulator_led_driver);
}
module_init(regulator_led_init);
static void __exit regulator_led_exit(void)
{
platform_driver_unregister(&regulator_led_driver);
}
module_exit(regulator_led_exit);
MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
MODULE_DESCRIPTION("Regulator driven LED driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:leds-regulator");
/*
* leds-regulator.h - platform data structure for regulator driven LEDs.
*
* Copyright (C) 2009 Antonio Ospite <ospite@studenti.unina.it>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#ifndef __LINUX_LEDS_REGULATOR_H
#define __LINUX_LEDS_REGULATOR_H
/*
* Use "vled" as supply id when declaring the regulator consumer:
*
* static struct regulator_consumer_supply pcap_regulator_VVIB_consumers [] = {
* { .dev_name = "leds-regulator.0", supply = "vled" },
* };
*
* If you have several regulator driven LEDs, you can append a numerical id to
* .dev_name as done above, and use the same id when declaring the platform
* device:
*
* static struct led_regulator_platform_data a780_vibrator_data = {
* .name = "a780::vibrator",
* };
*
* static struct platform_device a780_vibrator = {
* .name = "leds-regulator",
* .id = 0,
* .dev = {
* .platform_data = &a780_vibrator_data,
* },
* };
*/
#include <linux/leds.h>
struct led_regulator_platform_data {
char *name; /* LED name as expected by LED class */
enum led_brightness brightness; /* initial brightness value */
};
#endif /* __LINUX_LEDS_REGULATOR_H */
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