/*
* LED driver for WM8350 driven LEDS.
*
* Copyright(C) 2007, 2008 Wolfson Microelectronics PLC.
*
* 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/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/mfd/wm8350/pmic.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/module.h>
/* Microamps */
static const int isink_cur[] = {
4,
5,
6,
7,
8,
10,
11,
14,
16,
19,
23,
27,
32,
39,
46,
54,
65,
77,
92,
109,
130,
154,
183,
218,
259,
308,
367,
436,
518,
616,
733,
872,
1037,
1233,
1466,
1744,
2073,
2466,
2933,
3487,
4147,
4932,
5865,
6975,
8294,
9864,
11730,
13949,
16589,
19728,
23460,
27899,
33178,
39455,
46920,
55798,
66355,
78910,
93840,
111596,
132710,
157820,
187681,
223191
};
#define to_wm8350_led(led_cdev) \
container_of(led_cdev, struct wm8350_led, cdev)
static void wm8350_led_enable(struct wm8350_led *led)
{
int ret;
if (led->enabled)
return;
ret = regulator_enable(led->isink);
if (ret != 0) {
dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n", ret);
return;
}
ret = regulator_enable(led->dcdc);
if (ret != 0) {
dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n", ret);
regulator_disable(led->isink);
return;
}
led->enabled = 1;
}
static void wm8350_led_disable(struct wm8350_led *led)
{
int ret;
if (!led->enabled)
return;
ret = regulator_disable(led->dcdc);
if (ret != 0) {
dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n", ret);
return;
}
ret = regulator_disable(led->isink);
if (ret != 0) {
dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n", ret);
ret = regulator_enable(led->dcdc);
if (ret != 0)
dev_err(led->cdev.dev, "Failed to reenable DCDC: %d\n",
ret);
return;
}
led->enabled = 0;
}
static void led_work(struct work_struct *work)
{
struct wm8350_led *led = container_of(work, struct wm8350_led, work);
int ret;
int uA;
unsigned long flags;
mutex_lock(&led->mutex);
spin_lock_irqsave(&led->value_lock, flags);
if (led->value == LED_OFF) {
spin_unlock_irqrestore(&led->value_lock, flags);
wm8350_led_disable(led);
goto out;
}
/* This scales linearly into the index of valid current
* settings which results in a linear scaling of perceived
* brightness due to the non-linear current settings provided
* by the hardware.
*/
uA = (led->max_uA_index * led->value) / LED_FULL;
spin_unlock_irqrestore(&led->value_lock, flags);
BUG_ON(uA >= ARRAY_SIZE(isink_cur));
ret = regulator_set_current_limit(led->isink, isink_cur[uA],
isink_cur[uA]);
if (ret != 0)
dev_err(led->cdev.dev, "Failed to set %duA: %d\n",
isink_cur[uA], ret);
wm8350_led_enable(led);
out:
mutex_unlock(&led->mutex);
}
static void wm8350_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct wm8350_led *led = to_wm8350_led(led_cdev);
unsigned long flags;
spin_lock_irqsave(&led->value_lock, flags);
led->value = value;
schedule_work(&led->work);
spin_unlock_irqrestore(&led->value_lock, flags);
}
static void wm8350_led_shutdown(struct platform_device *pdev)
{
struct wm8350_led *led = platform_get_drvdata(pdev);
mutex_lock(&led->mutex);
led->value = LED_OFF;
wm8350_led_disable(led);
mutex_unlock(&led->mutex);
}
static int wm8350_led_probe(struct platform_device *pdev)
{
struct regulator *isink, *dcdc;
struct wm8350_led *led;
struct wm8350_led_platform_data *pdata = pdev->dev.platform_data;
int i;
if (pdata == NULL) {
dev_err(&pdev->dev, "no platform data\n");
return -ENODEV;
}
if (pdata->max_uA < isink_cur[0]) {
dev_err(&pdev->dev, "Invalid maximum current %duA\n",
pdata->max_uA);
return -EINVAL;
}
isink = devm_regulator_get(&pdev->dev, "led_isink");
if (IS_ERR(isink)) {
dev_err(&pdev->dev, "%s: can't get ISINK\n", __func__);
return PTR_ERR(isink);
}
dcdc = devm_regulator_get(&pdev->dev, "led_vcc");
if (IS_ERR(dcdc)) {
dev_err(&pdev->dev, "%s: can't get DCDC\n", __func__);
return PTR_ERR(dcdc);
}
led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
if (led == NULL)
return -ENOMEM;
led->cdev.brightness_set = wm8350_led_set;
led->cdev.default_trigger = pdata->default_trigger;
led->cdev.name = pdata->name;
led->cdev.flags |= LED_CORE_SUSPENDRESUME;
led->enabled = regulator_is_enabled(isink);
led->isink = isink;
led->dcdc = dcdc;
for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++)
if (isink_cur[i] >= pdata->max_uA)
break;
led->max_uA_index = i;
if (pdata->max_uA != isink_cur[i])
dev_warn(&pdev->dev,
"Maximum current %duA is not directly supported,"
" check platform data\n",
pdata->max_uA);
spin_lock_init(&led->value_lock);
mutex_init(&led->mutex);
INIT_WORK(&led->work, led_work);
led->value = LED_OFF;
platform_set_drvdata(pdev, led);
return led_classdev_register(&pdev->dev, &led->cdev);
}
static int wm8350_led_remove(struct platform_device *pdev)
{
struct wm8350_led *led = platform_get_drvdata(pdev);
led_classdev_unregister(&led->cdev);
flush_work(&led->work);
wm8350_led_disable(led);
return 0;
}
static struct platform_driver wm8350_led_driver = {
.driver = {
.name = "wm8350-led",
.owner = THIS_MODULE,
},
.probe = wm8350_led_probe,
.remove = wm8350_led_remove,
.shutdown = wm8350_led_shutdown,
};
module_platform_driver(wm8350_led_driver);
MODULE_AUTHOR("Mark Brown");
MODULE_DESCRIPTION("WM8350 LED driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm8350-led");
