drm/radeon: enable ABGR and XBGR formats (v2)

Add support for DRM_FORMAT_{A,X}BGR8888 in atombios_crtc
Swapping of red and blue channels is implemented for radeon chipsets:
DCE2/R6xx and later - crossbar registers defined where needed and used
DCE1/R5xx - AVIVO_D1GRPH_SWAP_RB bit is used

(v2) Set AVIVO_D1GRPH_SWAP_RB bit in fb_format, using bitwise OR for DCE1 path
     Use bitwise OR where required for big endian settings in fb_swap
     Use existing code style CHIP_R600 condition, fix typo in R600 blue crossbar
Signed-off-by: Mauro Rossi <issor.oruam@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/atombios_crtc.c

@@ -1254,6 +1254,16 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
 		/* Greater 8 bpc fb needs to bypass hw-lut to retain precision */
 		bypass_lut = true;
 		break;
+	case DRM_FORMAT_XBGR8888:
+	case DRM_FORMAT_ABGR8888:
+		fb_format = (EVERGREEN_GRPH_DEPTH(EVERGREEN_GRPH_DEPTH_32BPP) |
+			     EVERGREEN_GRPH_FORMAT(EVERGREEN_GRPH_FORMAT_ARGB8888));
+		fb_swap = (EVERGREEN_GRPH_RED_CROSSBAR(EVERGREEN_GRPH_RED_SEL_B) |
+			   EVERGREEN_GRPH_BLUE_CROSSBAR(EVERGREEN_GRPH_BLUE_SEL_R));
+#ifdef __BIG_ENDIAN
+		fb_swap |= EVERGREEN_GRPH_ENDIAN_SWAP(EVERGREEN_GRPH_ENDIAN_8IN32);
+#endif
+		break;
 	default:
 		DRM_ERROR("Unsupported screen format %s\n",
 		          drm_get_format_name(target_fb->format->format, &format_name));
@@ -1551,6 +1561,21 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
 		/* Greater 8 bpc fb needs to bypass hw-lut to retain precision */
 		bypass_lut = true;
 		break;
+	case DRM_FORMAT_XBGR8888:
+	case DRM_FORMAT_ABGR8888:
+		fb_format =
+		    AVIVO_D1GRPH_CONTROL_DEPTH_32BPP |
+		    AVIVO_D1GRPH_CONTROL_32BPP_ARGB8888;
+		if (rdev->family >= CHIP_R600)
+			fb_swap =
+			    (R600_D1GRPH_RED_CROSSBAR(R600_D1GRPH_RED_SEL_B) |
+			     R600_D1GRPH_BLUE_CROSSBAR(R600_D1GRPH_BLUE_SEL_R));
+		else /* DCE1 (R5xx) */
+			fb_format |= AVIVO_D1GRPH_SWAP_RB;
+#ifdef __BIG_ENDIAN
+		fb_swap |= R600_D1GRPH_SWAP_ENDIAN_32BIT;
+#endif
+		break;
 	default:
 		DRM_ERROR("Unsupported screen format %s\n",
 		          drm_get_format_name(target_fb->format->format, &format_name));

drivers/gpu/drm/radeon/r600_reg.h

@@ -87,11 +87,32 @@
 #define R600_MEDIUM_VID_LOWER_GPIO_CNTL                            0x720
 #define R600_LOW_VID_LOWER_GPIO_CNTL                               0x724
 
-#define R600_D1GRPH_SWAP_CONTROL                               0x610C
-#       define R600_D1GRPH_SWAP_ENDIAN_NONE                    (0 << 0)
-#       define R600_D1GRPH_SWAP_ENDIAN_16BIT                   (1 << 0)
-#       define R600_D1GRPH_SWAP_ENDIAN_32BIT                   (2 << 0)
-#       define R600_D1GRPH_SWAP_ENDIAN_64BIT                   (3 << 0)
+#define R600_D1GRPH_SWAP_CONTROL                     0x610C
+#       define R600_D1GRPH_ENDIAN_SWAP(x)            (((x) & 0x3) << 0)
+#       define R600_D1GRPH_SWAP_ENDIAN_NONE          0
+#       define R600_D1GRPH_SWAP_ENDIAN_16BIT         1
+#       define R600_D1GRPH_SWAP_ENDIAN_32BIT         2
+#       define R600_D1GRPH_SWAP_ENDIAN_64BIT         3
+#       define R600_D1GRPH_RED_CROSSBAR(x)           (((x) & 0x3) << 4)
+#       define R600_D1GRPH_RED_SEL_R                 0
+#       define R600_D1GRPH_RED_SEL_G                 1
+#       define R600_D1GRPH_RED_SEL_B                 2
+#       define R600_D1GRPH_RED_SEL_A                 3
+#       define R600_D1GRPH_GREEN_CROSSBAR(x)         (((x) & 0x3) << 6)
+#       define R600_D1GRPH_GREEN_SEL_G               0
+#       define R600_D1GRPH_GREEN_SEL_B               1
+#       define R600_D1GRPH_GREEN_SEL_A               2
+#       define R600_D1GRPH_GREEN_SEL_R               3
+#       define R600_D1GRPH_BLUE_CROSSBAR(x)          (((x) & 0x3) << 8)
+#       define R600_D1GRPH_BLUE_SEL_B                0
+#       define R600_D1GRPH_BLUE_SEL_A                1
+#       define R600_D1GRPH_BLUE_SEL_R                2
+#       define R600_D1GRPH_BLUE_SEL_G                3
+#       define R600_D1GRPH_ALPHA_CROSSBAR(x)         (((x) & 0x3) << 10)
+#       define R600_D1GRPH_ALPHA_SEL_A               0
+#       define R600_D1GRPH_ALPHA_SEL_R               1
+#       define R600_D1GRPH_ALPHA_SEL_G               2
+#       define R600_D1GRPH_ALPHA_SEL_B               3
 
 #define R600_HDP_NONSURFACE_BASE                                0x2c04