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path: root/drivers/video/backlight/generic_bl.c
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Diffstat (limited to 'drivers/video/backlight/generic_bl.c')
-rw-r--r--drivers/video/backlight/generic_bl.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/drivers/video/backlight/generic_bl.c b/drivers/video/backlight/generic_bl.c
new file mode 100644
index 00000000000..6d27f62fdcd
--- /dev/null
+++ b/drivers/video/backlight/generic_bl.c
@@ -0,0 +1,147 @@
+/*
+ * Generic Backlight Driver
+ *
+ * Copyright (c) 2004-2008 Richard Purdie
+ *
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+
+static int genericbl_intensity;
+static struct backlight_device *generic_backlight_device;
+static struct generic_bl_info *bl_machinfo;
+
+/* Flag to signal when the battery is low */
+#define GENERICBL_BATTLOW BL_CORE_DRIVER1
+
+static int genericbl_send_intensity(struct backlight_device *bd)
+{
+ int intensity = bd->props.brightness;
+
+ if (bd->props.power != FB_BLANK_UNBLANK)
+ intensity = 0;
+ if (bd->props.state & BL_CORE_FBBLANK)
+ intensity = 0;
+ if (bd->props.state & BL_CORE_SUSPENDED)
+ intensity = 0;
+ if (bd->props.state & GENERICBL_BATTLOW)
+ intensity &= bl_machinfo->limit_mask;
+
+ bl_machinfo->set_bl_intensity(intensity);
+
+ genericbl_intensity = intensity;
+
+ if (bl_machinfo->kick_battery)
+ bl_machinfo->kick_battery();
+
+ return 0;
+}
+
+static int genericbl_get_intensity(struct backlight_device *bd)
+{
+ return genericbl_intensity;
+}
+
+/*
+ * Called when the battery is low to limit the backlight intensity.
+ * If limit==0 clear any limit, otherwise limit the intensity
+ */
+void corgibl_limit_intensity(int limit)
+{
+ struct backlight_device *bd = generic_backlight_device;
+
+ mutex_lock(&bd->ops_lock);
+ if (limit)
+ bd->props.state |= GENERICBL_BATTLOW;
+ else
+ bd->props.state &= ~GENERICBL_BATTLOW;
+ backlight_update_status(generic_backlight_device);
+ mutex_unlock(&bd->ops_lock);
+}
+EXPORT_SYMBOL(corgibl_limit_intensity);
+
+static struct backlight_ops genericbl_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .get_brightness = genericbl_get_intensity,
+ .update_status = genericbl_send_intensity,
+};
+
+static int genericbl_probe(struct platform_device *pdev)
+{
+ struct generic_bl_info *machinfo = pdev->dev.platform_data;
+ const char *name = "generic-bl";
+ struct backlight_device *bd;
+
+ bl_machinfo = machinfo;
+ if (!machinfo->limit_mask)
+ machinfo->limit_mask = -1;
+
+ if (machinfo->name)
+ name = machinfo->name;
+
+ bd = backlight_device_register (name,
+ &pdev->dev, NULL, &genericbl_ops);
+ if (IS_ERR (bd))
+ return PTR_ERR (bd);
+
+ platform_set_drvdata(pdev, bd);
+
+ bd->props.max_brightness = machinfo->max_intensity;
+ bd->props.power = FB_BLANK_UNBLANK;
+ bd->props.brightness = machinfo->default_intensity;
+ backlight_update_status(bd);
+
+ generic_backlight_device = bd;
+
+ printk("Generic Backlight Driver Initialized.\n");
+ return 0;
+}
+
+static int genericbl_remove(struct platform_device *pdev)
+{
+ struct backlight_device *bd = platform_get_drvdata(pdev);
+
+ bd->props.power = 0;
+ bd->props.brightness = 0;
+ backlight_update_status(bd);
+
+ backlight_device_unregister(bd);
+
+ printk("Generic Backlight Driver Unloaded\n");
+ return 0;
+}
+
+static struct platform_driver genericbl_driver = {
+ .probe = genericbl_probe,
+ .remove = genericbl_remove,
+ .driver = {
+ .name = "generic-bl",
+ },
+};
+
+static int __init genericbl_init(void)
+{
+ return platform_driver_register(&genericbl_driver);
+}
+
+static void __exit genericbl_exit(void)
+{
+ platform_driver_unregister(&genericbl_driver);
+}
+
+module_init(genericbl_init);
+module_exit(genericbl_exit);
+
+MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
+MODULE_DESCRIPTION("Generic Backlight Driver");
+MODULE_LICENSE("GPL");