Staging
v0.5.2
v0.5.2
https://github.com/torvalds/linux
Tip revision: 0c744ea4f77d72b3dcebb7a8f2684633ec79be88 authored by Linus Torvalds on 01 January 2017, 22:31:53 UTC
Linux 4.10-rc2
Linux 4.10-rc2
Tip revision: 0c744ea
lcd.c
/*
* LCD Lowlevel Control Abstraction
*
* Copyright (C) 2003,2004 Hewlett-Packard Company
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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>
#include <linux/slab.h>
#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
defined(CONFIG_LCD_CLASS_DEVICE_MODULE))
/* 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 = data;
/* If we aren't interested in this event, skip it immediately ... */
switch (event) {
case FB_EVENT_BLANK:
case FB_EVENT_MODE_CHANGE:
case FB_EVENT_MODE_CHANGE_ALL:
case FB_EARLY_EVENT_BLANK:
case FB_R_EARLY_EVENT_BLANK:
break;
default:
return 0;
}
ld = container_of(self, struct lcd_device, fb_notif);
if (!ld->ops)
return 0;
mutex_lock(&ld->ops_lock);
if (!ld->ops->check_fb || ld->ops->check_fb(ld, evdata->info)) {
if (event == FB_EVENT_BLANK) {
if (ld->ops->set_power)
ld->ops->set_power(ld, *(int *)evdata->data);
} else if (event == FB_EARLY_EVENT_BLANK) {
if (ld->ops->early_set_power)
ld->ops->early_set_power(ld,
*(int *)evdata->data);
} else if (event == FB_R_EARLY_EVENT_BLANK) {
if (ld->ops->r_early_set_power)
ld->ops->r_early_set_power(ld,
*(int *)evdata->data);
} else {
if (ld->ops->set_mode)
ld->ops->set_mode(ld, evdata->data);
}
}
mutex_unlock(&ld->ops_lock);
return 0;
}
static int lcd_register_fb(struct lcd_device *ld)
{
memset(&ld->fb_notif, 0, sizeof(ld->fb_notif));
ld->fb_notif.notifier_call = fb_notifier_callback;
return fb_register_client(&ld->fb_notif);
}
static void lcd_unregister_fb(struct lcd_device *ld)
{
fb_unregister_client(&ld->fb_notif);
}
#else
static int lcd_register_fb(struct lcd_device *ld)
{
return 0;
}
static inline void lcd_unregister_fb(struct lcd_device *ld)
{
}
#endif /* CONFIG_FB */
static ssize_t lcd_power_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
int rc;
struct lcd_device *ld = to_lcd_device(dev);
mutex_lock(&ld->ops_lock);
if (ld->ops && ld->ops->get_power)
rc = sprintf(buf, "%d\n", ld->ops->get_power(ld));
else
rc = -ENXIO;
mutex_unlock(&ld->ops_lock);
return rc;
}
static ssize_t lcd_power_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
int rc;
struct lcd_device *ld = to_lcd_device(dev);
unsigned long power;
rc = kstrtoul(buf, 0, &power);
if (rc)
return rc;
rc = -ENXIO;
mutex_lock(&ld->ops_lock);
if (ld->ops && ld->ops->set_power) {
pr_debug("set power to %lu\n", power);
ld->ops->set_power(ld, power);
rc = count;
}
mutex_unlock(&ld->ops_lock);
return rc;
}
static DEVICE_ATTR_RW(lcd_power);
static ssize_t contrast_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int rc = -ENXIO;
struct lcd_device *ld = to_lcd_device(dev);
mutex_lock(&ld->ops_lock);
if (ld->ops && ld->ops->get_contrast)
rc = sprintf(buf, "%d\n", ld->ops->get_contrast(ld));
mutex_unlock(&ld->ops_lock);
return rc;
}
static ssize_t contrast_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
int rc;
struct lcd_device *ld = to_lcd_device(dev);
unsigned long contrast;
rc = kstrtoul(buf, 0, &contrast);
if (rc)
return rc;
rc = -ENXIO;
mutex_lock(&ld->ops_lock);
if (ld->ops && ld->ops->set_contrast) {
pr_debug("set contrast to %lu\n", contrast);
ld->ops->set_contrast(ld, contrast);
rc = count;
}
mutex_unlock(&ld->ops_lock);
return rc;
}
static DEVICE_ATTR_RW(contrast);
static ssize_t max_contrast_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct lcd_device *ld = to_lcd_device(dev);
return sprintf(buf, "%d\n", ld->props.max_contrast);
}
static DEVICE_ATTR_RO(max_contrast);
static struct class *lcd_class;
static void lcd_device_release(struct device *dev)
{
struct lcd_device *ld = to_lcd_device(dev);
kfree(ld);
}
static struct attribute *lcd_device_attrs[] = {
&dev_attr_lcd_power.attr,
&dev_attr_contrast.attr,
&dev_attr_max_contrast.attr,
NULL,
};
ATTRIBUTE_GROUPS(lcd_device);
/**
* 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 device. The
* methods may retrieve it by using lcd_get_data(ld).
* @ops: the lcd operations structure.
*
* Creates and registers a new lcd device. Returns either an ERR_PTR()
* or a pointer to the newly allocated device.
*/
struct lcd_device *lcd_device_register(const char *name, struct device *parent,
void *devdata, struct lcd_ops *ops)
{
struct lcd_device *new_ld;
int rc;
pr_debug("lcd_device_register: name=%s\n", name);
new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL);
if (!new_ld)
return ERR_PTR(-ENOMEM);
mutex_init(&new_ld->ops_lock);
mutex_init(&new_ld->update_lock);
new_ld->dev.class = lcd_class;
new_ld->dev.parent = parent;
new_ld->dev.release = lcd_device_release;
dev_set_name(&new_ld->dev, "%s", name);
dev_set_drvdata(&new_ld->dev, devdata);
rc = device_register(&new_ld->dev);
if (rc) {
put_device(&new_ld->dev);
return ERR_PTR(rc);
}
rc = lcd_register_fb(new_ld);
if (rc) {
device_unregister(&new_ld->dev);
return ERR_PTR(rc);
}
new_ld->ops = ops;
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)
{
if (!ld)
return;
mutex_lock(&ld->ops_lock);
ld->ops = NULL;
mutex_unlock(&ld->ops_lock);
lcd_unregister_fb(ld);
device_unregister(&ld->dev);
}
EXPORT_SYMBOL(lcd_device_unregister);
static void devm_lcd_device_release(struct device *dev, void *res)
{
struct lcd_device *lcd = *(struct lcd_device **)res;
lcd_device_unregister(lcd);
}
static int devm_lcd_device_match(struct device *dev, void *res, void *data)
{
struct lcd_device **r = res;
return *r == data;
}
/**
* devm_lcd_device_register - resource managed lcd_device_register()
* @dev: the device to register
* @name: the name of the device
* @parent: a pointer to the parent device
* @devdata: an optional pointer to be stored for private driver use
* @ops: the lcd operations structure
*
* @return a struct lcd on success, or an ERR_PTR on error
*
* Managed lcd_device_register(). The lcd_device returned from this function
* are automatically freed on driver detach. See lcd_device_register()
* for more information.
*/
struct lcd_device *devm_lcd_device_register(struct device *dev,
const char *name, struct device *parent,
void *devdata, struct lcd_ops *ops)
{
struct lcd_device **ptr, *lcd;
ptr = devres_alloc(devm_lcd_device_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return ERR_PTR(-ENOMEM);
lcd = lcd_device_register(name, parent, devdata, ops);
if (!IS_ERR(lcd)) {
*ptr = lcd;
devres_add(dev, ptr);
} else {
devres_free(ptr);
}
return lcd;
}
EXPORT_SYMBOL(devm_lcd_device_register);
/**
* devm_lcd_device_unregister - resource managed lcd_device_unregister()
* @dev: the device to unregister
* @ld: the lcd device to unregister
*
* Deallocated a lcd allocated with devm_lcd_device_register(). Normally
* this function will not need to be called and the resource management
* code will ensure that the resource is freed.
*/
void devm_lcd_device_unregister(struct device *dev, struct lcd_device *ld)
{
int rc;
rc = devres_release(dev, devm_lcd_device_release,
devm_lcd_device_match, ld);
WARN_ON(rc);
}
EXPORT_SYMBOL(devm_lcd_device_unregister);
static void __exit lcd_class_exit(void)
{
class_destroy(lcd_class);
}
static int __init lcd_class_init(void)
{
lcd_class = class_create(THIS_MODULE, "lcd");
if (IS_ERR(lcd_class)) {
pr_warn("Unable to create backlight class; errno = %ld\n",
PTR_ERR(lcd_class));
return PTR_ERR(lcd_class);
}
lcd_class->dev_groups = lcd_device_groups;
return 0;
}
/*
* 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");