1 files changed, 264 insertions, 0 deletions

diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
new file mode 100644
index 000000000000..acc81cb01d56
--- /dev/null
+++ b/drivers/video/backlight/backlight.c
@@ -0,0 +1,264 @@
+/*
+ * Backlight 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/backlight.h>
+#include <linux/notifier.h>
+#include <linux/ctype.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <asm/bug.h>
+
+static ssize_t backlight_show_power(struct class_device *cdev, char *buf)
+{
+        int rc;
+        struct backlight_device *bd = to_backlight_device(cdev);
+
+        down(&bd->sem);
+        if (likely(bd->props && bd->props->get_power))
+                rc = sprintf(buf, "%d\n", bd->props->get_power(bd));
+        else
+                rc = -ENXIO;
+        up(&bd->sem);
+
+        return rc;
+}
+
+static ssize_t backlight_store_power(struct class_device *cdev, const char *buf, size_t count)
+{
+        int rc, power;
+        char *endp;
+        struct backlight_device *bd = to_backlight_device(cdev);
+
+        power = simple_strtoul(buf, &endp, 0);
+        if (*endp && !isspace(*endp))
+                return -EINVAL;
+
+        down(&bd->sem);
+        if (likely(bd->props && bd->props->set_power)) {
+                pr_debug("backlight: set power to %d\n", power);
+                bd->props->set_power(bd, power);
+                rc = count;
+        } else
+                rc = -ENXIO;
+        up(&bd->sem);
+
+        return rc;
+}
+
+static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf)
+{
+        int rc;
+        struct backlight_device *bd = to_backlight_device(cdev);
+
+        down(&bd->sem);
+        if (likely(bd->props && bd->props->get_brightness))
+                rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
+        else
+                rc = -ENXIO;
+        up(&bd->sem);
+
+        return rc;
+}
+
+static ssize_t backlight_store_brightness(struct class_device *cdev, const char *buf, size_t count)
+{
+        int rc, brightness;
+        char *endp;
+        struct backlight_device *bd = to_backlight_device(cdev);
+
+        brightness = simple_strtoul(buf, &endp, 0);
+        if (*endp && !isspace(*endp))
+                return -EINVAL;
+
+        down(&bd->sem);
+        if (likely(bd->props && bd->props->set_brightness)) {
+                pr_debug("backlight: set brightness to %d\n", brightness);
+                bd->props->set_brightness(bd, brightness);
+                rc = count;
+        } else
+                rc = -ENXIO;
+        up(&bd->sem);
+
+        return rc;
+}
+
+static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *buf)
+{
+        int rc;
+        struct backlight_device *bd = to_backlight_device(cdev);
+
+        down(&bd->sem);
+        if (likely(bd->props))
+                rc = sprintf(buf, "%d\n", bd->props->max_brightness);
+        else
+                rc = -ENXIO;
+        up(&bd->sem);
+
+        return rc;
+}
+
+static void backlight_class_release(struct class_device *dev)
+{
+        struct backlight_device *bd = to_backlight_device(dev);
+        kfree(bd);
+}
+
+static struct class backlight_class = {
+        .name = "backlight",
+        .release = backlight_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 bl_class_device_attributes[] = {
+        DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power),
+        DECLARE_ATTR(brightness, 0644, backlight_show_brightness, backlight_store_brightness),
+        DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, 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 backlight power as well ...
+ */
+static int fb_notifier_callback(struct notifier_block *self,
+                                unsigned long event, void *data)
+{
+        struct backlight_device *bd;
+        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;
+
+        bd = container_of(self, struct backlight_device, fb_notif);
+        down(&bd->sem);
+        if (bd->props)
+                if (!bd->props->check_fb || bd->props->check_fb(evdata->info))
+                        bd->props->set_power(bd, *(int *)evdata->data);
+        up(&bd->sem);
+        return 0;
+}
+
+/**
+ * backlight_device_register - create and register a new object of
+ *   backlight_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(&bd->class_dev).
+ * @bp: the backlight properties structure.
+ *
+ * Creates and registers new backlight class_device. Returns either an
+ * ERR_PTR() or a pointer to the newly allocated device.
+ */
+struct backlight_device *backlight_device_register(const char *name, void *devdata,
+                                                   struct backlight_properties *bp)
+{
+        int i, rc;
+        struct backlight_device *new_bd;
+
+        pr_debug("backlight_device_alloc: name=%s\n", name);
+
+        new_bd = kmalloc(sizeof(struct backlight_device), GFP_KERNEL);
+        if (unlikely(!new_bd))
+                return ERR_PTR(ENOMEM);
+
+        init_MUTEX(&new_bd->sem);
+        new_bd->props = bp;
+        memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev));
+        new_bd->class_dev.class = &backlight_class;
+        strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN);
+        class_set_devdata(&new_bd->class_dev, devdata);
+
+        rc = class_device_register(&new_bd->class_dev);
+        if (unlikely(rc)) {
+error:          kfree(new_bd);
+                return ERR_PTR(rc);
+        }
+
+        memset(&new_bd->fb_notif, 0, sizeof(new_bd->fb_notif));
+        new_bd->fb_notif.notifier_call = fb_notifier_callback;
+
+        rc = fb_register_client(&new_bd->fb_notif);
+        if (unlikely(rc))
+                goto error;
+
+        for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) {
+                rc = class_device_create_file(&new_bd->class_dev,
+                                              &bl_class_device_attributes[i]);
+                if (unlikely(rc)) {
+                        while (--i >= 0)
+                                class_device_remove_file(&new_bd->class_dev,
+                                                         &bl_class_device_attributes[i]);
+                        class_device_unregister(&new_bd->class_dev);
+                        /* No need to kfree(new_bd) since release() method was called */
+                        return ERR_PTR(rc);
+                }
+        }
+
+        return new_bd;
+}
+EXPORT_SYMBOL(backlight_device_register);
+
+/**
+ * backlight_device_unregister - unregisters a backlight device object.
+ * @bd: the backlight device object to be unregistered and freed.
+ *
+ * Unregisters a previously registered via backlight_device_register object.
+ */
+void backlight_device_unregister(struct backlight_device *bd)
+{
+        int i;
+
+        if (!bd)
+                return;
+
+        pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id);
+
+        for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++)
+                class_device_remove_file(&bd->class_dev,
+                                         &bl_class_device_attributes[i]);
+
+        down(&bd->sem);
+        bd->props = NULL;
+        up(&bd->sem);
+
+        fb_unregister_client(&bd->fb_notif);
+
+        class_device_unregister(&bd->class_dev);
+}
+EXPORT_SYMBOL(backlight_device_unregister);
+
+static void __exit backlight_class_exit(void)
+{
+        class_unregister(&backlight_class);
+}
+
+static int __init backlight_class_init(void)
+{
+        return class_register(&backlight_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(backlight_class_init);
+module_exit(backlight_class_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
+MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");