Re: [PATCH] video:da8xx-fb: Add 24bpp LCD configuration support

LCD controller on am335x supports 24bpp raster configuration
in addition to ones on da850. LCDC also supports 24bpp in unpacked
format having ARGB:8888 32bpp format data in DDR, but it doesn't
interpret Alpha component of the data.

Signed-off-by: Manjunathappa, Prakash <redacted>
---
 drivers/video/da8xx-fb.c |   57 +++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 56 insertions(+), 1 deletions(-)

diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c
index 55f91d9..e111971 100644
--- a/drivers/video/da8xx-fb.c
+++ b/drivers/video/da8xx-fb.c

@@ -82,6 +82,8 @@
 #define LCD_V2_LIDD_CLK_EN		BIT(1)
 #define LCD_V2_CORE_CLK_EN		BIT(0)
 #define LCD_V2_LPP_B10			26
+#define LCD_V2_TFT_24BPP_MODE		BIT(25)
+#define LCD_V2_TFT_24BPP_UNPACK		BIT(26)
 
 /* LCD Raster Timing 2 Register */
 #define LCD_AC_BIAS_TRANSITIONS_PER_INT(x)	((x) << 16)

@@ -151,7 +153,7 @@ struct da8xx_fb_par {
 	unsigned int		dma_end;
 	struct clk *lcdc_clk;
 	int irq;
-	unsigned short pseudo_palette[16];
+	unsigned short pseudo_palette[32];

 	unsigned int palette_sz;
 	unsigned int pxl_clk;
 	int blank;

@@ -458,6 +460,9 @@ static int lcd_cfg_frame_buffer(struct da8xx_fb_par *par, u32 width, u32 height,
 {
 	u32 reg;
 
+	if ((bpp > 16) && (lcd_revision = LCD_VERSION_1))
+		return -EINVAL;
+
 	/* Set the Panel Width */
 	/* Pixels per line = (PPL + 1)*16 */
 	if (lcd_revision = LCD_VERSION_1) {

@@ -501,6 +506,13 @@ static int lcd_cfg_frame_buffer(struct da8xx_fb_par *par, u32 width, u32 height,
 	reg = lcdc_read(LCD_RASTER_CTRL_REG) & ~(1 << 8);
 	if (raster_order)
 		reg |= LCD_RASTER_ORDER;
+
+	if (bpp = 24)
+		reg |= (LCD_TFT_MODE | LCD_V2_TFT_24BPP_MODE);
+	else if (bpp = 32)
+		reg |= (LCD_TFT_MODE | LCD_V2_TFT_24BPP_MODE
+				| LCD_V2_TFT_24BPP_UNPACK);
+
 	lcdc_write(reg, LCD_RASTER_CTRL_REG);
 
 	switch (bpp) {

@@ -508,6 +520,8 @@ static int lcd_cfg_frame_buffer(struct da8xx_fb_par *par, u32 width, u32 height,
 	case 2:
 	case 4:
 	case 16:
+	case 24:
+	case 32:
 		par->palette_sz = 16 * 2;
 		break;
 

@@ -537,6 +551,9 @@ static int fb_setcolreg(unsigned regno, unsigned red, unsigned green,
 	if (info->fix.visual = FB_VISUAL_DIRECTCOLOR)
 		return 1;
 
+	if ((info->var.bits_per_pixel > 16) && (lcd_revision = LCD_VERSION_1))
+		return 1;
+
 	if (info->var.bits_per_pixel = 8) {
 		red >>= 4;
 		green >>= 8;

@@ -566,6 +583,23 @@ static int fb_setcolreg(unsigned regno, unsigned red, unsigned green,
 			update_hw = 1;
 			palette[0] = 0x4000;
 		}
+	} else if (((info->var.bits_per_pixel = 32) && regno < 32) ||
+		    ((info->var.bits_per_pixel = 24) && regno < 24)) {
+		red >>= (24 - info->var.red.length);
+		red <<= info->var.red.offset;
+
+		green >>= (24 - info->var.green.length);
+		green <<= info->var.green.offset;
+
+		blue >>= (24 - info->var.blue.length);
+		blue <<= info->var.blue.offset;
+
+		par->pseudo_palette[regno] = red | green | blue;
+
+		if (palette[0] != 0x4000) {
+			update_hw = 1;
+			palette[0] = 0x4000;
+		}
 	}
 
 	/* Update the palette in the h/w as needed. */

@@ -777,6 +811,9 @@ static int fb_check_var(struct fb_var_screeninfo *var,
 {
 	int err = 0;
 
+	if ((var->bits_per_pixel > 16) && (lcd_revision = LCD_VERSION_1))
+		return -EINVAL;
+
 	switch (var->bits_per_pixel) {
 	case 1:
 	case 8:

@@ -809,6 +846,24 @@ static int fb_check_var(struct fb_var_screeninfo *var,
 		var->transp.offset = 0;
 		var->transp.length = 0;
 		break;
+	case 24:
+		var->red.offset = 16;
+		var->red.length = 8;
+		var->green.offset = 8;
+		var->green.length = 8;
+		var->blue.offset = 0;
+		var->blue.length = 8;
+		break;
+	case 32:
+		var->transp.offset = 24;
+		var->transp.length = 8;
+		var->red.offset = 16;
+		var->red.length = 8;
+		var->green.offset = 8;
+		var->green.length = 8;
+		var->blue.offset = 0;
+		var->blue.length = 8;
+		break;
 	default:
 		err = -EINVAL;
 	}