1 files changed, 263 insertions, 0 deletions
diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c
new file mode 100644
index 000000000000..470e6f0ee4dd
--- /dev/null
+++ b/drivers/video/backlight/lcd.c
@@ -0,0 +1,263 @@
+/*
+ * LCD Lowlevel Control Abstraction
+ *
+ * Copyright (C) 2003,2004 Hewlett-Packard Company
+ *
+ */
+
+#include <linux/version.h>
+#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 <asm/bug.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, power;
+	char *endp;
+	struct lcd_device *ld = to_lcd_device(cdev);
+
+	power = simple_strtoul(buf, &endp, 0);
+	if (*endp && !isspace(*endp))
+		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;
+	} else
+		rc = -ENXIO;
+	up(&ld->sem);
+
+	return rc;
+}
+
+static ssize_t lcd_show_contrast(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_contrast))
+		rc = sprintf(buf, "%d\n", ld->props->get_contrast(ld));
+	else
+		rc = -ENXIO;
+	up(&ld->sem);
+
+	return rc;
+}
+
+static ssize_t lcd_store_contrast(struct class_device *cdev, const char *buf, size_t count)
+{
+	int rc, contrast;
+	char *endp;
+	struct lcd_device *ld = to_lcd_device(cdev);
+
+	contrast = simple_strtoul(buf, &endp, 0);
+	if (*endp && !isspace(*endp))
+		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;
+	} else
+		rc = -ENXIO;
+	up(&ld->sem);
+
+	return rc;
+}
+
+static ssize_t lcd_show_max_contrast(struct class_device *cdev, char *buf)
+{
+	int rc;
+	struct lcd_device *ld = to_lcd_device(cdev);
+
+	down(&ld->sem);
+	if (likely(ld->props))
+		rc = sprintf(buf, "%d\n", ld->props->max_contrast);
+	else
+		rc = -ENXIO;
+	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");