/*
* LED driver for WM831x status LEDs
*
* Copyright(C) 2009 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/slab.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/mfd/wm831x/status.h>
struct wm831x_status {
struct led_classdev cdev;
struct wm831x *wm831x;
struct work_struct work;
struct mutex mutex;
spinlock_t value_lock;
int reg; /* Control register */
int reg_val; /* Control register value */
int blink;
int blink_time;
int blink_cyc;
int src;
enum led_brightness brightness;
};
#define to_wm831x_status(led_cdev) \
container_of(led_cdev, struct wm831x_status, cdev)
static void wm831x_status_work(struct work_struct *work)
{
struct wm831x_status *led = container_of(work, struct wm831x_status,
work);
unsigned long flags;
mutex_lock(&led->mutex);
led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);
spin_lock_irqsave(&led->value_lock, flags);
led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
if (led->blink) {
led->reg_val |= 2 << WM831X_LED_MODE_SHIFT;
led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT;
led->reg_val |= led->blink_cyc;
} else {
if (led->brightness != LED_OFF)
led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
}
spin_unlock_irqrestore(&led->value_lock, flags);
wm831x_reg_write(led->wm831x, led->reg, led->reg_val);
mutex_unlock(&led->mutex);
}
static void wm831x_status_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct wm831x_status *led = to_wm831x_status(led_cdev);
unsigned long flags;
spin_lock_irqsave(&led->value_lock, flags);
led->brightness = value;
if (value == LED_OFF)
led->blink = 0;
schedule_work(&led->work);
spin_unlock_irqrestore(&led->value_lock, flags);
}
static int wm831x_status_blink_set(struct led_classdev *led_cdev,
unsigned long *delay_on,
unsigned long *delay_off)
{
struct wm831x_status *led = to_wm831x_status(led_cdev);
unsigned long flags;
int ret = 0;
/* Pick some defaults if we've not been given times */
if (*delay_on == 0 && *delay_off == 0) {
*delay_on = 250;
*delay_off = 250;
}
spin_lock_irqsave(&led->value_lock, flags);
/* We only have a limited selection of settings, see if we can
* support the configuration we're being given */
switch (*delay_on) {
case 1000:
led->blink_time = 0;
break;
case 250:
led->blink_time = 1;
break;
case 125:
led->blink_time = 2;
break;
case 62:
case 63:
/* Actually 62.5ms */
led->blink_time = 3;
break;
default:
ret = -EINVAL;
break;
}
if (ret == 0) {
switch (*delay_off / *delay_on) {
case 1:
led->blink_cyc = 0;
break;
case 3:
led->blink_cyc = 1;
break;
case 4:
led->blink_cyc = 2;
break;
case 8:
led->blink_cyc = 3;
break;
default:
ret = -EINVAL;
break;
}
}
if (ret == 0)
led->blink = 1;
else
led->blink = 0;
/* Always update; if we fail turn off blinking since we expect
* a software fallback. */
schedule_work(&led->work);
spin_unlock_irqrestore(&led->value_lock, flags);
return ret;
}
static const char *led_src_texts[] = {
"otp",
"power",
"charger",
"soft",
};
static ssize_t wm831x_status_src_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct wm831x_status *led = to_wm831x_status(led_cdev);
int i;
ssize_t ret = 0;
mutex_lock(&led->mutex);
for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
if (i == led->src)
ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
else
ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);
mutex_unlock(&led->mutex);
ret += sprintf(&buf[ret], "\n");
return ret;
}
static ssize_t wm831x_status_src_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
struct led_classdev *led_cdev = dev_get_drvdata(dev);
struct wm831x_status *led = to_wm831x_status(led_cdev);
char name[20];
int i;
size_t len;
name[sizeof(name) - 1] = '\0';
strncpy(name, buf, sizeof(name) - 1);
len = strlen(name);
if (len && name[len - 1] == '\n')
name[len - 1] = '\0';
for (i = 0; i < ARRAY_SIZE(led_src_texts); i++) {
if (!strcmp(name, led_src_texts[i])) {
mutex_lock(&led->mutex);
led->src = i;
schedule_work(&led->work);
mutex_unlock(&led->mutex);
}
}
return size;
}
static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store);
static int wm831x_status_probe(struct platform_device *pdev)
{
struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
struct wm831x_pdata *chip_pdata;
struct wm831x_status_pdata pdata;
struct wm831x_status *drvdata;
struct resource *res;
int id = pdev->id % ARRAY_SIZE(chip_pdata->status);
int ret;
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (res == NULL) {
dev_err(&pdev->dev, "No I/O resource\n");
ret = -EINVAL;
goto err;
}
drvdata = kzalloc(sizeof(struct wm831x_status), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
dev_set_drvdata(&pdev->dev, drvdata);
drvdata->wm831x = wm831x;
drvdata->reg = res->start;
if (wm831x->dev->platform_data)
chip_pdata = wm831x->dev->platform_data;
else
chip_pdata = NULL;
memset(&pdata, 0, sizeof(pdata));
if (chip_pdata && chip_pdata->status[id])
memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));
else
pdata.name = dev_name(&pdev->dev);
mutex_init(&drvdata->mutex);
INIT_WORK(&drvdata->work, wm831x_status_work);
spin_lock_init(&drvdata->value_lock);
/* We cache the configuration register and read startup values
* from it. */
drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);
if (drvdata->reg_val & WM831X_LED_MODE_MASK)
drvdata->brightness = LED_FULL;
else
drvdata->brightness = LED_OFF;
/* Set a default source if configured, otherwise leave the
* current hardware setting.
*/
if (pdata.default_src == WM831X_STATUS_PRESERVE) {
drvdata->src = drvdata->reg_val;
drvdata->src &= WM831X_LED_SRC_MASK;
drvdata->src >>= WM831X_LED_SRC_SHIFT;
} else {
drvdata->src = pdata.default_src - 1;
}
drvdata->cdev.name = pdata.name;
drvdata->cdev.default_trigger = pdata.default_trigger;
drvdata->cdev.brightness_set = wm831x_status_set;
drvdata->cdev.blink_set = wm831x_status_blink_set;
ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
goto err_led;
}
ret = device_create_file(drvdata->cdev.dev, &dev_attr_src);
if (ret != 0)
dev_err(&pdev->dev,
"No source control for LED: %d\n", ret);
return 0;
err_led:
led_classdev_unregister(&drvdata->cdev);
kfree(drvdata);
err:
return ret;
}
static int wm831x_status_remove(struct platform_device *pdev)
{
struct wm831x_status *drvdata = platform_get_drvdata(pdev);
device_remove_file(drvdata->cdev.dev, &dev_attr_src);
led_classdev_unregister(&drvdata->cdev);
kfree(drvdata);
return 0;
}
static struct platform_driver wm831x_status_driver = {
.driver = {
.name = "wm831x-status",
.owner = THIS_MODULE,
},
.probe = wm831x_status_probe,
.remove = wm831x_status_remove,
};
static int __devinit wm831x_status_init(void)
{
return platform_driver_register(&wm831x_status_driver);
}
module_init(wm831x_status_init);
static void wm831x_status_exit(void)
{
platform_driver_unregister(&wm831x_status_driver);
}
module_exit(wm831x_status_exit);
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("WM831x status LED driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-status");
