pxafb: Add support for other palette formats

This patch adds support for the other three palette formats possible with
the PXA LCD controller. This is required on boards where an LCD is connected
with all its 18 bits. With this patch, it's possible to use an 8-bit mode
with 18-bit palette entries. This used to be possible in 2.4 kernels but
disappeared in 2.6. With current kernels, you can only get wrong colours
out of an LCD connected this way.

Users can choose the palette format by doing something like this
in their board definition:

static struct pxafb_mach_info my_fb_info = {
        [...]
        .lccr3          = LCCR3_OutEnH | LCCR3_PixFlEdg | LCCR3_PDFOR_3,
        .lccr4          = LCCR4_PAL_FOR_2,
        [...]
};

Signed-off-by: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 17 insertions, 1 deletions

diff --git a/include/asm-arm/arch-pxa/pxa-regs.h b/include/asm-arm/arch-pxa/pxa-regs.h
index 67f53e07db86..bb68b598c436 100644
--- a/include/asm-arm/arch-pxa/pxa-regs.h
+++ b/include/asm-arm/arch-pxa/pxa-regs.h
@@ -1823,6 +1823,7 @@
 #define LCCR1           __REG(0x44000004)  /* LCD Controller Control Register 1 */
 #define LCCR2           __REG(0x44000008)  /* LCD Controller Control Register 2 */
 #define LCCR3           __REG(0x4400000C)  /* LCD Controller Control Register 3 */
+#define LCCR4           __REG(0x44000010)  /* LCD Controller Control Register 3 */
 #define DFBR0           __REG(0x44000020)  /* DMA Channel 0 Frame Branch Register */
 #define DFBR1           __REG(0x44000024)  /* DMA Channel 1 Frame Branch Register */
 #define LCSR            __REG(0x44000038)  /* LCD Controller Status Register */
@@ -1836,6 +1837,16 @@
 #define LCCR3_8BPP (3 << 24)
 #define LCCR3_16BPP (4 << 24)
 
+#define LCCR3_PDFOR_0 (0 << 30)
+#define LCCR3_PDFOR_1 (1 << 30)
+#define LCCR3_PDFOR_2 (2 << 30)
+#define LCCR3_PDFOR_3 (3 << 30)
+
+#define LCCR4_PAL_FOR_0 (0 << 15)
+#define LCCR4_PAL_FOR_1 (1 << 15)
+#define LCCR4_PAL_FOR_2 (2 << 15)
+#define LCCR4_PAL_FOR_MASK (3 << 15)
+
 #define FDADR0          __REG(0x44000200)  /* DMA Channel 0 Frame Descriptor Address Register */
 #define FSADR0          __REG(0x44000204)  /* DMA Channel 0 Frame Source Address Register */
 #define FIDR0           __REG(0x44000208)  /* DMA Channel 0 Frame ID Register */
diff --git a/include/asm-arm/arch-pxa/pxafb.h b/include/asm-arm/arch-pxa/pxafb.h
index 81c3928d608c..ea2336aa70e4 100644
--- a/include/asm-arm/arch-pxa/pxafb.h
+++ b/include/asm-arm/arch-pxa/pxafb.h
@@ -70,7 +70,12 @@ struct pxafb_mach_info {
          *      LCCR3_HSP, LCCR3_VSP, LCCR0_Pcd(x), LCCR3_Bpp
          */
         u_int           lccr3;
-
+        /* The following should be defined in LCCR4
+         *      LCCR4_PAL_FOR_0 or LCCR4_PAL_FOR_1 or LCCR4_PAL_FOR_2
+         *
+         * All other bits in LCCR4 should be left alone.
+         */
+        u_int           lccr4;
         void (*pxafb_backlight_power)(int);
         void (*pxafb_lcd_power)(int, struct fb_var_screeninfo *);