[PATCH] backlight: Add backlight driver for Sharp Corgi PDAs

Add a backlight driver for the Sharp Corgi PDAs (SL-C7xx series) using the
backlight class.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/video/backlight/Kconfig

@@ -41,3 +41,12 @@ config LCD_DEVICE
 	bool
 	depends on LCD_CLASS_DEVICE
 	default y
+
+config BACKLIGHT_CORGI
+	tristate "Sharp Corgi Backlight Driver (SL-C7xx Series)"
+	depends on BACKLIGHT_DEVICE && PXA_SHARPSL
+	default y
+	help
+	  If you have a Sharp Zaurus SL-C7xx, say y to enable the
+	  backlight driver.
+

drivers/video/backlight/Makefile

@@ -2,3 +2,4 @@
 
 obj-$(CONFIG_LCD_CLASS_DEVICE)     += lcd.o
 obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE) += backlight.o
+obj-$(CONFIG_BACKLIGHT_CORGI)	+= corgi_bl.o

drivers/video/backlight/corgi_bl.c

+/*
+ *  Backlight Driver for Sharp Corgi
+ *
+ *  Copyright (c) 2004-2005 Richard Purdie
+ *
+ *  Based on Sharp's 2.4 Backlight Driver
+ *
+ *  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/device.h>
+#include <linux/spinlock.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+
+#include <asm/arch-pxa/corgi.h>
+#include <asm/hardware/scoop.h>
+
+#define CORGI_MAX_INTENSITY 		0x3e
+#define CORGI_DEFAULT_INTENSITY		0x1f
+#define CORGI_LIMIT_MASK			0x0b
+
+static int corgibl_powermode = FB_BLANK_UNBLANK;
+static int current_intensity = 0;
+static int corgibl_limit = 0;
+static spinlock_t bl_lock = SPIN_LOCK_UNLOCKED;
+
+static void corgibl_send_intensity(int intensity)
+{
+	unsigned long flags;
+	void (*corgi_kick_batt)(void);
+
+	if (corgibl_powermode != FB_BLANK_UNBLANK) {
+		intensity = 0;
+	} else {
+		if (corgibl_limit)
+			intensity &= CORGI_LIMIT_MASK;
+	}
+
+	/* Skip 0x20 as it will blank the display */
+	if (intensity >= 0x20)
+		intensity++;
+
+	spin_lock_irqsave(&bl_lock, flags);
+	/* Bits 0-4 are accessed via the SSP interface */
+	corgi_ssp_blduty_set(intensity & 0x1f);
+	/* Bit 5 is via SCOOP */
+	if (intensity & 0x0020)
+		set_scoop_gpio(CORGI_SCP_BACKLIGHT_CONT);
+	else
+		reset_scoop_gpio(CORGI_SCP_BACKLIGHT_CONT);
+	spin_unlock_irqrestore(&bl_lock, flags);
+}
+
+static void corgibl_blank(int blank)
+{
+	switch(blank) {
+
+	case FB_BLANK_NORMAL:
+	case FB_BLANK_VSYNC_SUSPEND:
+	case FB_BLANK_HSYNC_SUSPEND:
+	case FB_BLANK_POWERDOWN:
+		if (corgibl_powermode == FB_BLANK_UNBLANK) {
+			corgibl_send_intensity(0);
+			corgibl_powermode = blank;
+		}
+		break;
+	case FB_BLANK_UNBLANK:
+		if (corgibl_powermode != FB_BLANK_UNBLANK) {
+			corgibl_powermode = blank;
+			corgibl_send_intensity(current_intensity);
+		}
+		break;
+	}
+}
+
+#ifdef CONFIG_PM
+static int corgibl_suspend(struct device *dev, u32 state, u32 level)
+{
+	if (level == SUSPEND_POWER_DOWN)
+		corgibl_blank(FB_BLANK_POWERDOWN);
+	return 0;
+}
+
+static int corgibl_resume(struct device *dev, u32 level)
+{
+	if (level == RESUME_POWER_ON)
+		corgibl_blank(FB_BLANK_UNBLANK);
+	return 0;
+}
+#else
+#define corgibl_suspend	NULL
+#define corgibl_resume	NULL
+#endif
+
+
+static int corgibl_set_power(struct backlight_device *bd, int state)
+{
+	corgibl_blank(state);
+	return 0;
+}
+
+static int corgibl_get_power(struct backlight_device *bd)
+{
+	return corgibl_powermode;
+}
+
+static int corgibl_set_intensity(struct backlight_device *bd, int intensity)
+{
+	if (intensity > CORGI_MAX_INTENSITY)
+		intensity = CORGI_MAX_INTENSITY;
+	corgibl_send_intensity(intensity);
+	current_intensity=intensity;
+	return 0;
+}
+
+static int corgibl_get_intensity(struct backlight_device *bd)
+{
+	return current_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)
+{
+	corgibl_limit = (limit ? 1 : 0);
+	corgibl_send_intensity(current_intensity);
+}
+EXPORT_SYMBOL(corgibl_limit_intensity);
+
+
+static struct backlight_properties corgibl_data = {
+	.owner		= THIS_MODULE,
+	.get_power      = corgibl_get_power,
+	.set_power      = corgibl_set_power,
+	.max_brightness = CORGI_MAX_INTENSITY,
+	.get_brightness = corgibl_get_intensity,
+	.set_brightness = corgibl_set_intensity,
+};
+
+static struct backlight_device *corgi_backlight_device;
+
+static int __init corgibl_probe(struct device *dev)
+{
+	corgi_backlight_device = backlight_device_register ("corgi-bl",
+		NULL, &corgibl_data);
+	if (IS_ERR (corgi_backlight_device))
+		return PTR_ERR (corgi_backlight_device);
+
+	corgibl_set_intensity(NULL, CORGI_DEFAULT_INTENSITY);
+
+	printk("Corgi Backlight Driver Initialized.\n");
+	return 0;
+}
+
+static int corgibl_remove(struct device *dev)
+{
+	backlight_device_unregister(corgi_backlight_device);
+
+	corgibl_set_intensity(NULL, 0);
+
+	printk("Corgi Backlight Driver Unloaded\n");
+	return 0;
+}
+
+static struct device_driver corgibl_driver = {
+	.name		= "corgi-bl",
+	.bus		= &platform_bus_type,
+	.probe		= corgibl_probe,
+	.remove		= corgibl_remove,
+	.suspend	= corgibl_suspend,
+	.resume		= corgibl_resume,
+};
+
+static int __init corgibl_init(void)
+{
+	return driver_register(&corgibl_driver);
+}
+
+static void __exit corgibl_exit(void)
+{
+ 	driver_unregister(&corgibl_driver);
+}
+
+module_init(corgibl_init);
+module_exit(corgibl_exit);
+
+MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
+MODULE_DESCRIPTION("Corgi Backlight Driver");
+MODULE_LICENSE("GPLv2");