/*
* LCD Lowlevel Control Abstraction
*
* Copyright (C) 2003,2004 Hewlett-Packard Company
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/lcd.h>
#include <linux/notifier.h>
#include <linux/ctype.h>
#include <linux/err.h>
#include <linux/fb.h>
static ssize_t lcd_show_power(struct class_device *cdev, char *buf)
{
int rc;
struct lcd_device *ld = to_lcd_device(cdev);
down(&ld->sem);
if (likely(ld->props && ld->props->get_power))
rc = sprintf(buf, "%d\n", ld->props->get_power(ld));
else
rc = -ENXIO;
up(&ld->sem);
return rc;
}
static ssize_t lcd_store_power(struct class_device *cdev, const char *buf, size_t count)
{
int rc = -ENXIO;
char *endp;
struct lcd_device *ld = to_lcd_device(cdev);
int power = simple_strtoul(buf, &endp, 0);
size_t size = endp - buf;
if (*endp && isspace(*endp))
size++;
if (size != count)
return -EINVAL;
down(&ld->sem);
if (likely(ld->props && ld->props->set_power)) {
pr_debug("lcd: set power to %d\n", power);
ld->props->set_power(ld, power);
rc = count;
}
up(&ld->sem);
return rc;
}
static ssize_t lcd_show_contrast(struct class_device *cdev, char *buf)
{
int rc = -ENXIO;
struct lcd_device *ld = to_lcd_device(cdev);
down(&ld->sem);
if (likely(ld->props && ld->props->get_contrast))
rc = sprintf(buf, "%d\n", ld->props->get_contrast(ld));
up(&ld->sem);
return rc;
}
static ssize_t lcd_store_contrast(struct class_device *cdev, const char *buf, size_t count)
{
int rc = -ENXIO;
char *endp;
struct lcd_device *ld = to_lcd_device(cdev);
int contrast = simple_strtoul(buf, &endp, 0);
size_t size = endp - buf;
if (*endp && isspace(*endp))
size++;
if (size != count)
return -EINVAL;
down(&ld->sem);
if (likely(ld->props && ld->props->set_contrast)) {
pr_debug("lcd: set contrast to %d\n", contrast);
ld->props->set_contrast(ld, contrast);
rc = count;
}
up(&ld->sem);
return rc;
}
static ssize_t lcd_show_max_contrast(struct class_device *cdev, char *buf)
{
int rc = -ENXIO;
struct lcd_device *ld = to_lcd_device(cdev);
down(&ld->sem);
if (likely(ld->props))
rc = sprintf(buf, "%d\n", ld->props->max_contrast);
up(&ld->sem);
return rc;
}
static void lcd_class_release(struct class_device *dev)
{
struct lcd_device *ld = to_lcd_device(dev);
kfree(ld);
}
static struct class lcd_class = {
.name = "lcd",
.release = lcd_class_release,
};
#define DECLARE_ATTR(_name,_mode,_show,_store) \
{ \
.attr = { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE }, \
.show = _show, \
.store = _store, \
}
static struct class_device_attribute lcd_class_device_attributes[] = {
DECLARE_ATTR(power, 0644, lcd_show_power, lcd_store_power),
DECLARE_ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
DECLARE_ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
};
/* This callback gets called when something important happens inside a
* framebuffer driver. We're looking if that important event is blanking,
* and if it is, we're switching lcd power as well ...
*/
static int fb_notifier_callback(struct notifier_block *self,
unsigned long event, void *data)
{
struct lcd_device *ld;
struct fb_event *evdata =(struct fb_event *)data;
/* If we aren't interested in this event, skip it immediately ... */
if (event != FB_EVENT_BLANK)
return 0;
ld = container_of(self, struct lcd_device, fb_notif);
down(&ld->sem);
if (ld->props)
if (!ld->props->check_fb || ld->props->check_fb(evdata->info))
ld->props->set_power(ld, *(int *)evdata->data);
up(&ld->sem);
return 0;
}
/**
* lcd_device_register - register a new object of lcd_device class.
* @name: the name of the new object(must be the same as the name of the
* respective framebuffer device).
* @devdata: an optional pointer to be stored in the class_device. The
* methods may retrieve it by using class_get_devdata(ld->class_dev).
* @lp: the lcd properties structure.
*
* Creates and registers a new lcd class_device. Returns either an ERR_PTR()
* or a pointer to the newly allocated device.
*/
struct lcd_device *lcd_device_register(const char *name, void *devdata,
struct lcd_properties *lp)
{
int i, rc;
struct lcd_device *new_ld;
pr_debug("lcd_device_register: name=%s\n", name);
new_ld = kmalloc(sizeof(struct lcd_device), GFP_KERNEL);
if (unlikely(!new_ld))
return ERR_PTR(-ENOMEM);
init_MUTEX(&new_ld->sem);
new_ld->props = lp;
memset(&new_ld->class_dev, 0, sizeof(new_ld->class_dev));
new_ld->class_dev.class = &lcd_class;
strlcpy(new_ld->class_dev.class_id, name, KOBJ_NAME_LEN);
class_set_devdata(&new_ld->class_dev, devdata);
rc = class_device_register(&new_ld->class_dev);
if (unlikely(rc)) {
error: kfree(new_ld);
return ERR_PTR(rc);
}
memset(&new_ld->fb_notif, 0, sizeof(new_ld->fb_notif));
new_ld->fb_notif.notifier_call = fb_notifier_callback;
rc = fb_register_client(&new_ld->fb_notif);
if (unlikely(rc))
goto error;
for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++) {
rc = class_device_create_file(&new_ld->class_dev,
&lcd_class_device_attributes[i]);
if (unlikely(rc)) {
while (--i >= 0)
class_device_remove_file(&new_ld->class_dev,
&lcd_class_device_attributes[i]);
class_device_unregister(&new_ld->class_dev);
/* No need to kfree(new_ld) since release() method was called */
return ERR_PTR(rc);
}
}
return new_ld;
}
EXPORT_SYMBOL(lcd_device_register);
/**
* lcd_device_unregister - unregisters a object of lcd_device class.
* @ld: the lcd device object to be unregistered and freed.
*
* Unregisters a previously registered via lcd_device_register object.
*/
void lcd_device_unregister(struct lcd_device *ld)
{
int i;
if (!ld)
return;
pr_debug("lcd_device_unregister: name=%s\n", ld->class_dev.class_id);
for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++)
class_device_remove_file(&ld->class_dev,
&lcd_class_device_attributes[i]);
down(&ld->sem);
ld->props = NULL;
up(&ld->sem);
fb_unregister_client(&ld->fb_notif);
class_device_unregister(&ld->class_dev);
}
EXPORT_SYMBOL(lcd_device_unregister);
static void __exit lcd_class_exit(void)
{
class_unregister(&lcd_class);
}
static int __init lcd_class_init(void)
{
return class_register(&lcd_class);
}
/*
* if this is compiled into the kernel, we need to ensure that the
* class is registered before users of the class try to register lcd's
*/
postcore_initcall(lcd_class_init);
module_exit(lcd_class_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");
