Implement an argb cursor using the alpha layer.

  The code is <hash>ifdef'ed out by <hash>if SMI_CURSOR_ALPHA_PLANE
because the smi 502 hardware is buggy, but it appears to have worked
for some older hardware revisions (by looking at code available at
ftp.siliconmotion.com.tw).
  Keeping it at least for now, as it serves as a simple way to reproduce
the problems described in smi.h.

1 files changed, 169 insertions, 20 deletions

diff --git a/src/smi501_crtc.c b/src/smi501_crtc.c
index 565b67a..9e896b1 100644
--- a/src/smi501_crtc.c
+++ b/src/smi501_crtc.c
@@ -372,23 +372,49 @@ SMI501_CrtcSetCursorPosition(xf86CrtcPtr crtc, int x, int y)
 {
     ScrnInfoPtr		pScrn = crtc->scrn;
     SMIPtr		pSmi = SMIPTR(pScrn);
-    xf86CrtcConfigPtr	crtcConf = XF86_CRTC_CONFIG_PTR(pScrn);
+    xf86CrtcConfigPtr	crtcConf;
+#if SMI_CURSOR_ALPHA_PLANE
+    SMICrtcPrivatePtr	smi_crtc = SMICRTC(crtc);
+    MSOCRegPtr		mode;
+#endif
     int32_t		port, offset;
 
     ENTER();
 
-    if (x >= 0)
-	offset = x & SMI501_MASK_MAXBITS;
-    else
-	offset = (-x & SMI501_MASK_MAXBITS) | SMI501_MASK_BOUNDARY;
+#if SMI_CURSOR_ALPHA_PLANE
+    if (smi_crtc->argb_cursor) {
+	mode = pSmi->mode;
+
+	/* uncomment next line if you want to see it rendering the cursor */
+	/* x = y = 0; */
 
-    if (y >= 0)
-	offset |= (y & SMI501_MASK_MAXBITS) << 16;
+	mode->alpha_plane_tl.f.left = x;
+	mode->alpha_plane_tl.f.top = y;
+
+	mode->alpha_plane_br.f.right = x + SMI501_CURSOR_SIZE - 1;
+	mode->alpha_plane_br.f.bottom = y + SMI501_CURSOR_SIZE - 1;
+
+	WRITE_SCR(pSmi, ALPHA_PLANE_TL, mode->alpha_plane_tl.value);
+	WRITE_SCR(pSmi, ALPHA_PLANE_BR, mode->alpha_plane_br.value);
+    }
     else
-	offset |= ((-y & SMI501_MASK_MAXBITS) | SMI501_MASK_BOUNDARY) << 16;
+#endif
+    {
+	crtcConf = XF86_CRTC_CONFIG_PTR(pScrn);
+
+	if (x >= 0)
+	    offset = x & SMI501_MASK_MAXBITS;
+	else
+	    offset = (-x & SMI501_MASK_MAXBITS) | SMI501_MASK_BOUNDARY;
 
-    port = crtc == crtcConf->crtc[0] ? 0x00f4 : 0x0234;
-    WRITE_DCR(pSmi, port, offset);
+	if (y >= 0)
+	    offset |= (y & SMI501_MASK_MAXBITS) << 16;
+	else
+	    offset |= ((-y & SMI501_MASK_MAXBITS) | SMI501_MASK_BOUNDARY) << 16;
+
+	port = crtc == crtcConf->crtc[0] ? 0x00f4 : 0x0234;
+	WRITE_DCR(pSmi, port, offset);
+    }
 
     LEAVE();
 }
@@ -398,15 +424,32 @@ SMI501_CrtcShowCursor(xf86CrtcPtr crtc)
 {
     ScrnInfoPtr		pScrn = crtc->scrn;
     SMIPtr		pSmi = SMIPTR(pScrn);
-    xf86CrtcConfigPtr	crtcConf = XF86_CRTC_CONFIG_PTR(pScrn);
+    xf86CrtcConfigPtr	crtcConf;
+#if SMI_CURSOR_ALPHA_PLANE
+    SMICrtcPrivatePtr	smi_crtc = SMICRTC(crtc);
+    MSOCRegPtr		mode;
+#endif
     int32_t		port, value;
 
     ENTER();
 
-    port = crtc == crtcConf->crtc[0] ? 0x00f0 : 0x0230;
-    value = READ_DCR(pSmi, port);
-    value |= SMI501_MASK_HWCENABLE;
-    WRITE_DCR(pSmi, port, value);
+#if SMI_CURSOR_ALPHA_PLANE
+    if (smi_crtc->argb_cursor) {
+	mode = pSmi->mode;
+
+	mode->alpha_display_ctl.f.enable = 1;
+	WRITE_SCR(pSmi, ALPHA_DISPLAY_CTL, mode->alpha_display_ctl.value);
+    }
+    else
+#endif
+    {
+	crtcConf = XF86_CRTC_CONFIG_PTR(pScrn);
+
+	port = crtc == crtcConf->crtc[0] ? 0x00f0 : 0x0230;
+	value = READ_DCR(pSmi, port);
+	value |= SMI501_MASK_HWCENABLE;
+	WRITE_DCR(pSmi, port, value);
+    }
 
     LEAVE();
 }
@@ -416,15 +459,32 @@ SMI501_CrtcHideCursor(xf86CrtcPtr crtc)
 {
     ScrnInfoPtr		pScrn = crtc->scrn;
     SMIPtr		pSmi = SMIPTR(pScrn);
-    xf86CrtcConfigPtr	crtcConf = XF86_CRTC_CONFIG_PTR(pScrn);
+    xf86CrtcConfigPtr	crtcConf;
+#if SMI_CURSOR_ALPHA_PLANE
+    SMICrtcPrivatePtr	smi_crtc = SMICRTC(crtc);
+    MSOCRegPtr		mode;
+#endif
     int32_t		port, value;
 
     ENTER();
 
-    port = crtc == crtcConf->crtc[0] ? 0x00f0 : 0x0230;
-    value = READ_DCR(pSmi, port);
-    value &= ~SMI501_MASK_HWCENABLE;
-    WRITE_DCR(pSmi, port, value);
+#if SMI_CURSOR_ALPHA_PLANE
+    if (smi_crtc->argb_cursor) {
+	mode = pSmi->mode;
+
+	mode->alpha_display_ctl.f.enable = 0;
+	WRITE_SCR(pSmi, ALPHA_DISPLAY_CTL, mode->alpha_display_ctl.value);
+    }
+    else
+#endif
+    {
+	crtcConf = XF86_CRTC_CONFIG_PTR(pScrn);
+
+	port = crtc == crtcConf->crtc[0] ? 0x00f0 : 0x0230;
+	value = READ_DCR(pSmi, port);
+	value &= ~SMI501_MASK_HWCENABLE;
+	WRITE_DCR(pSmi, port, value);
+    }
 
     LEAVE();
 }
@@ -434,6 +494,9 @@ SMI501_CrtcLoadCursorImage(xf86CrtcPtr crtc, CARD8 *image)
 {
     ScrnInfoPtr		pScrn = crtc->scrn;
     SMIPtr		pSmi = SMIPTR(pScrn);
+#if SMI_CURSOR_ALPHA_PLANE
+    SMICrtcPrivatePtr	smi_crtc = SMICRTC(crtc);
+#endif
     xf86CrtcConfigPtr	crtcConf = XF86_CRTC_CONFIG_PTR(pScrn);
     int32_t		port, value;
 
@@ -445,10 +508,92 @@ SMI501_CrtcLoadCursorImage(xf86CrtcPtr crtc, CARD8 *image)
     memcpy(pSmi->FBBase + value, image,
 	   /* FIXME 1024, but then, should not be using 64x64 cursors */
 	   (SMI501_MAX_CURSOR >> 2) * SMI501_MAX_CURSOR);
+#if SMI_CURSOR_ALPHA_PLANE
+    smi_crtc->argb_cursor = FALSE;
+#endif
 
     LEAVE();
 }
 
+#if SMI_CURSOR_ALPHA_PLANE
+static void
+SMI501_CrtcLoadCursorArgb(xf86CrtcPtr crtc, CARD32 *image)
+{
+    ScrnInfoPtr		 pScrn = crtc->scrn;
+    SMIPtr		 pSmi = SMIPTR(pScrn);
+    SMICrtcPrivatePtr	 smi_crtc = SMICRTC(crtc);
+    MSOCRegPtr		 mode = pSmi->mode;
+    int16_t		*framebuffer;
+    int32_t		 x, y, bits;
+    int32_t		 format;
+
+    ENTER();
+
+#define ALPHA_RGB_565		1
+#define ALPHA_ARGB_4444		3
+
+    /* select alpha format */
+    mode->alpha_display_ctl.f.format = ALPHA_ARGB_4444;
+
+    /* 0: use per pixel alpha value  1: use alpha value specified in alpha */
+    if (mode->alpha_display_ctl.f.format == ALPHA_RGB_565) {
+	mode->alpha_display_ctl.f.select = 1;
+	/* 0 to 15, with 0 being transparent and 15 opaque */
+	mode->alpha_display_ctl.f.alpha = 7;
+    }
+    else {
+	/* use per pixel alpha */
+	mode->alpha_display_ctl.f.select = 0;
+    }
+
+    /* alpha layer buffer */
+    mode->alpha_fb_address.value = 0;
+    mode->alpha_fb_address.f.address = pSmi->FBCursorOffset >> 4;
+
+    /* more clearly: width = (SMI501_MAX_CURSOR << 1) >> 4
+     * as the structure is matching the register spec, where it says
+     * the first 4 bits are hardwired to zero */
+    mode->alpha_fb_width.f.offset = SMI501_MAX_CURSOR >> 3;
+    mode->alpha_fb_width.f.width = SMI501_MAX_CURSOR >> 3;
+
+    mode->alpha_chroma_key.f.value = 0;
+    mode->alpha_chroma_key.f.mask = 0;
+    /* enable chroma key */
+    mode->alpha_display_ctl.f.chromakey = 1;
+
+    framebuffer = (int16_t *)(pSmi->FBBase + pSmi->FBCursorOffset);
+    if (mode->alpha_display_ctl.f.format == ALPHA_RGB_565) {
+	/* convert image to rgb 5:6:5 */
+	for (y = 0; y < SMI501_MAX_CURSOR; y++) {
+	    for (x = 0; x < SMI501_MAX_CURSOR; x++) {
+		bits = image[y * SMI501_MAX_CURSOR + x];
+		framebuffer[y * SMI501_MAX_CURSOR + x] =
+		(((bits & 0xf80000) >> 8) |
+		 ((bits & 0x00fc00) >> 5) |
+		 ((bits & 0x0000f8) >> 3));
+	    }
+	}
+    }
+    else {
+	/* convert image to argb 4:4:4:4 */
+	for (y = 0; y < SMI501_MAX_CURSOR; y++) {
+	    for (x = 0; x < SMI501_MAX_CURSOR; x++) {
+		bits = image[y * SMI501_MAX_CURSOR + x];
+		framebuffer[y * SMI501_MAX_CURSOR + x] =
+		(((bits & 0xf0000000) >> 16) |
+		 ((bits & 0x00f00000) >> 12) |
+		 ((bits & 0x0000f000) >>  8) |
+		 ((bits & 0x000000f0) >>  4));
+	    }
+	}
+    }
+    SMI501_WriteMode_alpha(pScrn, mode);
+    smi_crtc->argb_cursor = TRUE;
+ 
+     LEAVE();
+ }
+#endif
+
 static xf86CrtcFuncsRec SMI501_Crtc0Funcs;
 static SMICrtcPrivateRec SMI501_Crtc0Priv;
 static xf86CrtcFuncsRec SMI501_Crtc1Funcs;
@@ -475,6 +620,10 @@ SMI501_CrtcPreInit(ScrnInfoPtr pScrn)
 	SMI501_Crtc0Funcs.show_cursor = SMI501_CrtcShowCursor;
 	SMI501_Crtc0Funcs.hide_cursor = SMI501_CrtcHideCursor;
 	SMI501_Crtc0Funcs.load_cursor_image = SMI501_CrtcLoadCursorImage;
+#if SMI_CURSOR_ALPHA_PLANE
+	if (!pSmi->Dualhead)
+	    SMI501_Crtc0Funcs.load_cursor_argb = SMI501_CrtcLoadCursorArgb;
+#endif
     }
 
     crtc0 = xf86CrtcCreate(pScrn, &SMI501_Crtc0Funcs);