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, 51 insertions, 15 deletions

diff --git a/drivers/video/pxafb.c b/drivers/video/pxafb.c
index f9b12ab5964..bfeb54ad3f0 100644
--- a/drivers/video/pxafb.c
+++ b/drivers/video/pxafb.c
@@ -108,20 +108,38 @@ pxafb_setpalettereg(u_int regno, u_int red, u_int green, u_int blue,
 		       u_int trans, struct fb_info *info)
 {
 	struct pxafb_info *fbi = (struct pxafb_info *)info;
-	u_int val, ret = 1;
+	u_int val;
 
-	if (regno < fbi->palette_size) {
-		if (fbi->fb.var.grayscale) {
-			val = ((blue >> 8) & 0x00ff);
-		} else {
-			val  = ((red   >>  0) & 0xf800);
-			val |= ((green >>  5) & 0x07e0);
-			val |= ((blue  >> 11) & 0x001f);
-		}
+	if (regno >= fbi->palette_size)
+		return 1;
+
+	if (fbi->fb.var.grayscale) {
+		fbi->palette_cpu[regno] = ((blue >> 8) & 0x00ff);
+		return 0;
+	}
+
+	switch (fbi->lccr4 & LCCR4_PAL_FOR_MASK) {
+	case LCCR4_PAL_FOR_0:
+		val  = ((red   >>  0) & 0xf800);
+		val |= ((green >>  5) & 0x07e0);
+		val |= ((blue  >> 11) & 0x001f);
 		fbi->palette_cpu[regno] = val;
-		ret = 0;
+		break;
+	case LCCR4_PAL_FOR_1:
+		val  = ((red   << 8) & 0x00f80000);
+		val |= ((green >> 0) & 0x0000fc00);
+		val |= ((blue  >> 8) & 0x000000f8);
+		((u32*)(fbi->palette_cpu))[regno] = val;
+		break;
+	case LCCR4_PAL_FOR_2:
+		val  = ((red   << 8) & 0x00fc0000);
+		val |= ((green >> 0) & 0x0000fc00);
+		val |= ((blue  >> 8) & 0x000000fc);
+		((u32*)(fbi->palette_cpu))[regno] = val;
+		break;
 	}
-	return ret;
+
+	return 0;
 }
 
 static int
@@ -363,7 +381,10 @@ static int pxafb_set_par(struct fb_info *info)
 	else
 		fbi->palette_size = var->bits_per_pixel == 1 ? 4 : 1 << var->bits_per_pixel;
 
-	palette_mem_size = fbi->palette_size * sizeof(u16);
+	if ((fbi->lccr4 & LCCR4_PAL_FOR_MASK) == LCCR4_PAL_FOR_0)
+		palette_mem_size = fbi->palette_size * sizeof(u16);
+	else
+		palette_mem_size = fbi->palette_size * sizeof(u32);
 
 	pr_debug("pxafb: palette_mem_size = 0x%08lx\n", palette_mem_size);
 
@@ -680,7 +701,13 @@ static int pxafb_activate_var(struct fb_var_screeninfo *var, struct pxafb_info *
 
 	fbi->dmadesc_palette_cpu->fsadr = fbi->palette_dma;
 	fbi->dmadesc_palette_cpu->fidr  = 0;
-	fbi->dmadesc_palette_cpu->ldcmd = (fbi->palette_size * 2) | LDCMD_PAL;
+	if ((fbi->lccr4 & LCCR4_PAL_FOR_MASK) == LCCR4_PAL_FOR_0)
+		fbi->dmadesc_palette_cpu->ldcmd = fbi->palette_size *
+							sizeof(u16);
+	else
+		fbi->dmadesc_palette_cpu->ldcmd = fbi->palette_size *
+							sizeof(u32);
+	fbi->dmadesc_palette_cpu->ldcmd |= LDCMD_PAL;
 
 	if (var->bits_per_pixel == 16) {
 		/* palette shouldn't be loaded in true-color mode */
@@ -719,6 +746,8 @@ static int pxafb_activate_var(struct fb_var_screeninfo *var, struct pxafb_info *
 	fbi->reg_lccr1 = new_regs.lccr1;
 	fbi->reg_lccr2 = new_regs.lccr2;
 	fbi->reg_lccr3 = new_regs.lccr3;
+	fbi->reg_lccr4 = LCCR4 & (~LCCR4_PAL_FOR_MASK);
+	fbi->reg_lccr4 |= (fbi->lccr4 & LCCR4_PAL_FOR_MASK);
 	set_hsync_time(fbi, pcd);
 	local_irq_restore(flags);
 
@@ -825,6 +854,7 @@ static void pxafb_enable_controller(struct pxafb_info *fbi)
 	pr_debug("LCCR1 0x%08x\n", (unsigned int) LCCR1);
 	pr_debug("LCCR2 0x%08x\n", (unsigned int) LCCR2);
 	pr_debug("LCCR3 0x%08x\n", (unsigned int) LCCR3);
+	pr_debug("LCCR4 0x%08x\n", (unsigned int) LCCR4);
 }
 
 static void pxafb_disable_controller(struct pxafb_info *fbi)
@@ -1094,10 +1124,13 @@ static int __init pxafb_map_video_memory(struct pxafb_info *fbi)
 		 * dma_writecombine_mmap)
 		 */
 		fbi->fb.fix.smem_start = fbi->screen_dma;
-
 		fbi->palette_size = fbi->fb.var.bits_per_pixel == 8 ? 256 : 16;
 
-		palette_mem_size = fbi->palette_size * sizeof(u16);
+		if ((fbi->lccr4 & LCCR4_PAL_FOR_MASK) == LCCR4_PAL_FOR_0)
+			palette_mem_size = fbi->palette_size * sizeof(u16);
+		else
+			palette_mem_size = fbi->palette_size * sizeof(u32);
+
 		pr_debug("pxafb: palette_mem_size = 0x%08lx\n", palette_mem_size);
 
 		fbi->palette_cpu = (u16 *)(fbi->map_cpu + PAGE_SIZE - palette_mem_size);
@@ -1160,6 +1193,7 @@ static struct pxafb_info * __init pxafb_init_fbinfo(struct device *dev)
 
 	fbi->lccr0			= inf->lccr0;
 	fbi->lccr3			= inf->lccr3;
+	fbi->lccr4			= inf->lccr4;
 	fbi->state			= C_STARTUP;
 	fbi->task_state			= (u_char)-1;
 
diff --git a/drivers/video/pxafb.h b/drivers/video/pxafb.h
index f8605b807b0..d920b8a14c3 100644
--- a/drivers/video/pxafb.h
+++ b/drivers/video/pxafb.h
@@ -71,6 +71,7 @@ struct pxafb_info {
 
 	u_int			lccr0;
 	u_int			lccr3;
+	u_int			lccr4;
 	u_int			cmap_inverse:1,
 				cmap_static:1,
 				unused:30;
@@ -79,6 +80,7 @@ struct pxafb_info {
 	u_int			reg_lccr1;
 	u_int			reg_lccr2;
 	u_int			reg_lccr3;
+	u_int			reg_lccr4;
 
 	unsigned long	hsync_time;