ARM: pxa/raumfeld: adapt to upcoming hardware change

The backlight control is going to change back to PWM in the
upcoming Raumfeld Controller hardware revision.

Signed-off-by: Sven Neumann <s.neumann@raumfeld.com>
Acked-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>

arch/arm/mach-pxa/raumfeld.c

@@ -598,14 +598,15 @@ static void __init raumfeld_lcd_init(void)
 
 	pxa_set_fb_info(NULL, &raumfeld_sharp_lcd_info);
 
-	/* Earlier devices had the backlight regulator controlled
-	 * via PWM, later versions use another controller for that */
-	if ((system_rev & 0xff) < 2) {
+	/* Hardware revision 2 has the backlight regulator controlled
+	 * by an LT3593, earlier and later devices use PWM for that. */
+	if ((system_rev & 0xff) == 2) {
+		platform_device_register(&raumfeld_lt3593_device);
+	} else {
 		mfp_cfg_t raumfeld_pwm_pin_config = GPIO17_PWM0_OUT;
 		pxa3xx_mfp_config(&raumfeld_pwm_pin_config, 1);
 		platform_device_register(&raumfeld_pwm_backlight_device);
-	} else
-		platform_device_register(&raumfeld_lt3593_device);
+	}
 
 	ret = gpio_request(GPIO_TFT_VA_EN, "display VA enable");
 	if (ret < 0)