[ARM] pxa: mainstone: update backlight to use the backlight infrastructure

Linux has framebuffer backlight support infrastructure which should
be used to expose backlight attributes.  Mainstone should use it.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 50 insertions, 10 deletions

diff --git a/arch/arm/mach-pxa/mainstone.c b/arch/arm/mach-pxa/mainstone.c
index 41d8c6cea62b..a5db00c38f1f 100644
--- a/arch/arm/mach-pxa/mainstone.c
+++ b/arch/arm/mach-pxa/mainstone.c
@@ -23,6 +23,7 @@
 #include <linux/ioport.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
+#include <linux/backlight.h>
 
 #include <asm/types.h>
 #include <asm/setup.h>
@@ -263,21 +264,60 @@ static struct platform_device mst_flash_device[2] = {
         },
 };
 
-static void mainstone_backlight_power(int on)
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
+static int mainstone_backlight_update_status(struct backlight_device *bl)
 {
-        if (on) {
+        int brightness = bl->props.brightness;
+
+        if (bl->props.power != FB_BLANK_UNBLANK ||
+            bl->props.fb_blank != FB_BLANK_UNBLANK)
+                brightness = 0;
+
+        if (brightness != 0) {
                 pxa_gpio_mode(GPIO16_PWM0_MD);
                 pxa_set_cken(CKEN_PWM0, 1);
-                PWM_CTRL0 = 0;
-                PWM_PWDUTY0 = 0x3ff;
-                PWM_PERVAL0 = 0x3ff;
-        } else {
-                PWM_CTRL0 = 0;
-                PWM_PWDUTY0 = 0x0;
-                PWM_PERVAL0 = 0x3FF;
+        }
+        PWM_CTRL0 = 0;
+        PWM_PWDUTY0 = brightness;
+        PWM_PERVAL0 = bl->props.max_brightness;
+        if (brightness == 0)
                 pxa_set_cken(CKEN_PWM0, 0);
+        return 0; /* pointless return value */
+}
+
+static int mainstone_backlight_get_brightness(struct backlight_device *bl)
+{
+        return PWM_PWDUTY0;
+}
+
+static /*const*/ struct backlight_ops mainstone_backlight_ops = {
+        .update_status  = mainstone_backlight_update_status,
+        .get_brightness = mainstone_backlight_get_brightness,
+};
+
+static void __init mainstone_backlight_register(void)
+{
+        struct backlight_device *bl;
+
+        bl = backlight_device_register("mainstone-bl", &pxa_device_fb.dev,
+                                       NULL, &mainstone_backlight_ops);
+        if (IS_ERR(bl)) {
+                printk(KERN_ERR "mainstone: unable to register backlight: %ld\n",
+                       PTR_ERR(bl));
+                return;
         }
+
+        /*
+         * broken design - register-then-setup interfaces are
+         * utterly broken by definition.
+         */
+        bl->props.max_brightness = 1023;
+        bl->props.brightness = 1023;
+        backlight_update_status(bl);
 }
+#else
+#define mainstone_backlight_register()  do { } while (0)
+#endif
 
 static struct pxafb_mode_info toshiba_ltm04c380k_mode = {
         .pixclock               = 50000,
@@ -311,7 +351,6 @@ static struct pxafb_mach_info mainstone_pxafb_info = {
         .num_modes              = 1,
         .lccr0                  = LCCR0_Act,
         .lccr3                  = LCCR3_PCP,
-        .pxafb_backlight_power  = mainstone_backlight_power,
 };
 
 static int mainstone_mci_init(struct device *dev, irq_handler_t mstone_detect_int, void *data)
@@ -473,6 +512,7 @@ static void __init mainstone_init(void)
                 mainstone_pxafb_info.modes = &toshiba_ltm035a776c_mode;
 
         set_pxa_fb_info(&mainstone_pxafb_info);
+        mainstone_backlight_register();
 
         pxa_set_mci_info(&mainstone_mci_platform_data);
         pxa_set_ficp_info(&mainstone_ficp_platform_data);