[ARM] pxafb: cleanup of the color format manipulation code

1. introduce var_to_depth() to calculate the color depth including the
   transparency bit

2. the conversion from 'fb_var_screeninfo' to LCCR3 BPP bits can be re-
   used by overlays (in OVLxC1), thus an individual pxafb_var_to_bpp()
   has been separated out.

3. pxafb_setmode() should really set the color bitfields correctly at
   begining, introduce a pxafb_set_pixfmt() for this

4. allow user apps to specify color formats within fb_var_screeninfo,
   and checking of this in pxafb_check_var() has been simplified as
   below:

   a) pxafb_var_to_bpp() should pass - which means a basically correct
      bits_per_pixel and color depth setting
   b) the RGBT bitfields are then forced into supported values by
      pxafb_set_pixfmt()

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Eric Miao <ycmiao@ycmiao-hp520.(none)>

diff --git a/arch/arm/mach-pxa/include/mach/regs-lcd.h b/arch/arm/mach-pxa/include/mach/regs-lcd.h
index 5c52226..aff3b87 100644 (file)
--- a/arch/arm/mach-pxa/include/mach/regs-lcd.h
+++ b/arch/arm/mach-pxa/include/mach/regs-lcd.h
@@ -28,17 +28,7 @@
 #define CMDCR          (0x100) /* Command Control Register */
 #define PRSR           (0x104) /* Panel Read Status Register */
 
-#define LCCR3_1BPP     (0 << 24)
-#define LCCR3_2BPP     (1 << 24)
-#define LCCR3_4BPP     (2 << 24)
-#define LCCR3_8BPP     (3 << 24)
-#define LCCR3_16BPP    (4 << 24)
-#define LCCR3_18BPP    (5 << 24)
-#define LCCR3_18BPP_P  (6 << 24)
-#define LCCR3_19BPP    (7 << 24)
-#define LCCR3_19BPP_P  (1 << 29)
-#define LCCR3_24BPP    ((1 << 29) | (1 << 24))
-#define LCCR3_25BPP    ((1 << 29) | (2 << 24))
+#define LCCR3_BPP(x)   ((((x) & 0x7) << 24) | (((x) & 0x8) ? (1 << 29) : 0))
 
 #define LCCR3_PDFOR_0  (0 << 30)
 #define LCCR3_PDFOR_1  (1 << 30)
@@ -133,9 +123,6 @@
 #define LCCR3_PCD      Fld (8, 0)      /* Pixel Clock Divisor */
 #define LCCR3_PixClkDiv(Div)   (((Div) << FShft (LCCR3_PCD)))
 
-#define LCCR3_BPP      Fld (3, 24)     /* Bit Per Pixel */
-#define LCCR3_Bpp(Bpp) (((Bpp) << FShft (LCCR3_BPP)))
-
 #define LCCR3_ACB      Fld (8, 8)      /* AC Bias */
 #define LCCR3_Acb(Acb) (((Acb) << FShft (LCCR3_ACB)))
 

diff --git a/drivers/video/pxafb.c b/drivers/video/pxafb.c
index c57f909..1faf526 100644 (file)
--- a/drivers/video/pxafb.c
+++ b/drivers/video/pxafb.c
@@ -66,7 +66,7 @@
                                         LCCR0_SFM | LCCR0_LDM | LCCR0_ENB)
 
 #define LCCR3_INVALID_CONFIG_MASK      (LCCR3_HSP | LCCR3_VSP |\
-                                        LCCR3_PCD | LCCR3_BPP)
+                                        LCCR3_PCD | LCCR3_BPP(0xf))
 
 static int pxafb_activate_var(struct fb_var_screeninfo *var,
                                struct pxafb_info *);
@@ -221,37 +221,110 @@ pxafb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
        return ret;
 }
 
-/*
- *  pxafb_bpp_to_lccr3():
- *    Convert a bits per pixel value to the correct bit pattern for LCCR3
- */
-static int pxafb_bpp_to_lccr3(struct fb_var_screeninfo *var)
+/* calculate pixel depth, transparency bit included, >=16bpp formats _only_ */
+static inline int var_to_depth(struct fb_var_screeninfo *var)
 {
-       int ret = 0;
+       return var->red.length + var->green.length +
+               var->blue.length + var->transp.length;
+}
+
+/* calculate 4-bit BPP value for LCCR3 and OVLxC1 */
+static int pxafb_var_to_bpp(struct fb_var_screeninfo *var)
+{
+       int bpp = -EINVAL;
+
        switch (var->bits_per_pixel) {
-       case 1:  ret = LCCR3_1BPP; break;
-       case 2:  ret = LCCR3_2BPP; break;
-       case 4:  ret = LCCR3_4BPP; break;
-       case 8:  ret = LCCR3_8BPP; break;
-       case 16: ret = LCCR3_16BPP; break;
+       case 1:  bpp = 0; break;
+       case 2:  bpp = 1; break;
+       case 4:  bpp = 2; break;
+       case 8:  bpp = 3; break;
+       case 16: bpp = 4; break;
        case 24:
-               switch (var->red.length + var->green.length +
-                               var->blue.length + var->transp.length) {
-               case 18: ret = LCCR3_18BPP_P | LCCR3_PDFOR_3; break;
-               case 19: ret = LCCR3_19BPP_P; break;
+               switch (var_to_depth(var)) {
+               case 18: bpp = 6; break; /* 18-bits/pixel packed */
+               case 19: bpp = 8; break; /* 19-bits/pixel packed */
+               case 24: bpp = 9; break;
                }
                break;
        case 32:
-               switch (var->red.length + var->green.length +
-                               var->blue.length + var->transp.length) {
-               case 18: ret = LCCR3_18BPP | LCCR3_PDFOR_3; break;
-               case 19: ret = LCCR3_19BPP; break;
-               case 24: ret = LCCR3_24BPP | LCCR3_PDFOR_3; break;
-               case 25: ret = LCCR3_25BPP; break;
+               switch (var_to_depth(var)) {
+               case 18: bpp = 5; break; /* 18-bits/pixel unpacked */
+               case 19: bpp = 7; break; /* 19-bits/pixel unpacked */
+               case 25: bpp = 10; break;
                }
                break;
        }
-       return ret;
+       return bpp;
+}
+
+/*
+ *  pxafb_var_to_lccr3():
+ *    Convert a bits per pixel value to the correct bit pattern for LCCR3
+ *
+ *  NOTE: for PXA27x with overlays support, the LCCR3_PDFOR_x bits have an
+ *  implication of the acutal use of transparency bit,  which we handle it
+ *  here separatedly. See PXA27x Developer's Manual, Section <<7.4.6 Pixel
+ *  Formats>> for the valid combination of PDFOR, PAL_FOR for various BPP.
+ *
+ *  Transparency for palette pixel formats is not supported at the moment.
+ */
+static uint32_t pxafb_var_to_lccr3(struct fb_var_screeninfo *var)
+{
+       int bpp = pxafb_var_to_bpp(var);
+       uint32_t lccr3;
+
+       if (bpp < 0)
+               return 0;
+
+       lccr3 = LCCR3_BPP(bpp);
+
+       switch (var_to_depth(var)) {
+       case 16: lccr3 |= var->transp.length ? LCCR3_PDFOR_3 : 0; break;
+       case 18: lccr3 |= LCCR3_PDFOR_3; break;
+       case 24: lccr3 |= var->transp.length ? LCCR3_PDFOR_2 : LCCR3_PDFOR_3;
+                break;
+       case 19:
+       case 25: lccr3 |= LCCR3_PDFOR_0; break;
+       }
+       return lccr3;
+}
+
+#define SET_PIXFMT(v, r, g, b, t)                              \
+({                                                             \
+       (v)->transp.offset = (t) ? (r) + (g) + (b) : 0;         \
+       (v)->transp.length = (t) ? (t) : 0;                     \
+       (v)->blue.length   = (b); (v)->blue.offset = 0;         \
+       (v)->green.length  = (g); (v)->green.offset = (b);      \
+       (v)->red.length    = (r); (v)->red.offset = (b) + (g);  \
+})
+
+/* set the RGBT bitfields of fb_var_screeninf according to
+ * var->bits_per_pixel and given depth
+ */
+static void pxafb_set_pixfmt(struct fb_var_screeninfo *var, int depth)
+{
+       if (depth == 0)
+               depth = var->bits_per_pixel;
+
+       if (var->bits_per_pixel < 16) {
+               /* indexed pixel formats */
+               var->red.offset    = 0; var->red.length    = 8;
+               var->green.offset  = 0; var->green.length  = 8;
+               var->blue.offset   = 0; var->blue.length   = 8;
+               var->transp.offset = 0; var->transp.length = 8;
+       }
+
+       switch (depth) {
+       case 16: var->transp.length ?
+                SET_PIXFMT(var, 5, 5, 5, 1) :          /* RGBT555 */
+                SET_PIXFMT(var, 5, 6, 5, 0); break;    /* RGB565 */
+       case 18: SET_PIXFMT(var, 6, 6, 6, 0); break;    /* RGB666 */
+       case 19: SET_PIXFMT(var, 6, 6, 6, 1); break;    /* RGBT666 */
+       case 24: var->transp.length ?
+                SET_PIXFMT(var, 8, 8, 7, 1) :          /* RGBT887 */
+                SET_PIXFMT(var, 8, 8, 8, 0); break;    /* RGB888 */
+       case 25: SET_PIXFMT(var, 8, 8, 8, 1); break;    /* RGBT888 */
+       }
 }
 
 #ifdef CONFIG_CPU_FREQ
@@ -313,6 +386,9 @@ static void pxafb_setmode(struct fb_var_screeninfo *var,
        var->lower_margin       = mode->lower_margin;
        var->sync               = mode->sync;
        var->grayscale          = mode->cmap_greyscale;
+
+       /* set the initial RGBA bitfields */
+       pxafb_set_pixfmt(var, mode->depth);
 }
 
 /*
@@ -328,6 +404,7 @@ static int pxafb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 {
        struct pxafb_info *fbi = (struct pxafb_info *)info;
        struct pxafb_mach_info *inf = fbi->dev->platform_data;
+       int err;
 
        if (var->xres < MIN_XRES)
                var->xres = MIN_XRES;
@@ -359,60 +436,12 @@ static int pxafb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
        else
                var->yres_virtual = max(var->yres_virtual, var->yres);
 
-       /*
-        * Setup the RGB parameters for this display.
-        *
-        * The pixel packing format is described on page 7-11 of the
-        * PXA2XX Developer's Manual.
-        */
-       if (var->bits_per_pixel == 16) {
-               var->red.offset   = 11; var->red.length   = 5;
-               var->green.offset = 5;  var->green.length = 6;
-               var->blue.offset  = 0;  var->blue.length  = 5;
-               var->transp.offset = var->transp.length = 0;
-       } else if (var->bits_per_pixel > 16) {
-               struct pxafb_mode_info *mode;
+       /* do a test conversion to BPP fields to check the color formats */
+       err = pxafb_var_to_bpp(var);
+       if (err < 0)
+               return err;
 
-               mode = pxafb_getmode(inf, var);
-               if (!mode)
-                       return -EINVAL;
-
-               switch (mode->depth) {
-               case 18: /* RGB666 */
-                       var->transp.offset = var->transp.length     = 0;
-                       var->red.offset    = 12; var->red.length    = 6;
-                       var->green.offset  = 6;  var->green.length  = 6;
-                       var->blue.offset   = 0;  var->blue.length   = 6;
-                       break;
-               case 19: /* RGBT666 */
-                       var->transp.offset = 18; var->transp.length = 1;
-                       var->red.offset    = 12; var->red.length    = 6;
-                       var->green.offset  = 6;  var->green.length  = 6;
-                       var->blue.offset   = 0;  var->blue.length   = 6;
-                       break;
-               case 24: /* RGB888 */
-                       var->transp.offset = var->transp.length     = 0;
-                       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 25: /* RGBT888 */
-                       var->transp.offset = 24; var->transp.length = 1;
-                       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:
-                       return -EINVAL;
-               }
-       } else {
-               var->red.offset = var->green.offset = 0;
-               var->blue.offset = var->transp.offset = 0;
-               var->red.length   = 8;
-               var->green.length = 8;
-               var->blue.length  = 8;
-               var->transp.length = 0;
-       }
+       pxafb_set_pixfmt(var, var_to_depth(var));
 
 #ifdef CONFIG_CPU_FREQ
        pr_debug("pxafb: dma period = %d ps\n",
@@ -978,7 +1007,7 @@ static int pxafb_activate_var(struct fb_var_screeninfo *var,
                (LCCR0_LDM | LCCR0_SFM | LCCR0_IUM | LCCR0_EFM |
                 LCCR0_QDM | LCCR0_BM  | LCCR0_OUM);
 
-       fbi->reg_lccr3 |= pxafb_bpp_to_lccr3(var);
+       fbi->reg_lccr3 |= pxafb_var_to_lccr3(var);
 
        fbi->reg_lccr4 = lcd_readl(fbi, LCCR4) & ~LCCR4_PAL_FOR_MASK;
        fbi->reg_lccr4 |= (fbi->lccr4 & LCCR4_PAL_FOR_MASK);