V4L/DVB (5077): Bttv cropping support

Adds the missing VIDIOC_CROPCAP, G_CROP and S_CROP ioctls, permitting 
applications to capture or overlay a subsection of the picture or to 
extend the capture window beyond active video, into the VBI area and the 
horizontal blanking. VBI capturing can start and end on any line, 
including the picture area, and apps can capture different lines of each 
field and single fields.
For compatibility with existing applications, the open() function
resets the cropping and VBI capturing parameters and a VIDIOC_S_CROP
call is necessary to actually enable cropping. 
Regrettably in PAL-M, PAL-N, PAL-Nc and NTSC-JP mode the maximum image 
width will increase from 640 and 768 to 747 and 923 pixels respectively.
Like the VBI changes however, this should only affect applications which 
depend on former driver limitations, such as never getting more than 640 
pixels regardless of the requested width. 
Also, new freedoms require additional checks for conflicts and some 
applications may not expect an EBUSY error from the VIDIOC_QBUF and 
VIDIOCMCAPTURE ioctls. These errors should be rare though.
So far, the patch has been tested on a UP machine with a bt878 in PAL-
BGHI and NTSC-M mode using xawtv, tvtime, mplayer/mencoder, zapping/
libzvbi and these tools: http://zapping.sf.net/bttv-crop-test.tar.bz2
I'd be grateful about comments or bug reports.

Signed-off-by: Michael H. Schimek <mschimek@gmx.at>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 140 insertions, 31 deletions

diff --git a/drivers/media/video/bt8xx/bttv-risc.c b/drivers/media/video/bt8xx/bttv-risc.c
index afcfe71e379..e7104d9cb4b 100644
--- a/drivers/media/video/bt8xx/bttv-risc.c
+++ b/drivers/media/video/bt8xx/bttv-risc.c
@@ -43,7 +43,8 @@ int
 bttv_risc_packed(struct bttv *btv, struct btcx_riscmem *risc,
 		 struct scatterlist *sglist,
 		 unsigned int offset, unsigned int bpl,
-		 unsigned int padding, unsigned int lines)
+		 unsigned int padding, unsigned int skip_lines,
+		 unsigned int store_lines)
 {
 	u32 instructions,line,todo;
 	struct scatterlist *sg;
@@ -54,9 +55,11 @@ bttv_risc_packed(struct bttv *btv, struct btcx_riscmem *risc,
 	   one write per scan line + sync + jump (all 2 dwords).  padding
 	   can cause next bpl to start close to a page border.  First DMA
 	   region may be smaller than PAGE_SIZE */
-	instructions  = 1 + ((bpl + padding) * lines) / PAGE_SIZE + lines;
-	instructions += 2;
-	if ((rc = btcx_riscmem_alloc(btv->c.pci,risc,instructions*8)) < 0)
+	instructions  = skip_lines * 4;
+	instructions += (1 + ((bpl + padding) * store_lines)
+			 / PAGE_SIZE + store_lines) * 8;
+	instructions += 2 * 8;
+	if ((rc = btcx_riscmem_alloc(btv->c.pci,risc,instructions)) < 0)
 		return rc;
 
 	/* sync instruction */
@@ -64,11 +67,16 @@ bttv_risc_packed(struct bttv *btv, struct btcx_riscmem *risc,
 	*(rp++) = cpu_to_le32(BT848_RISC_SYNC|BT848_FIFO_STATUS_FM1);
 	*(rp++) = cpu_to_le32(0);
 
+	while (skip_lines-- > 0) {
+		*(rp++) = cpu_to_le32(BT848_RISC_SKIP | BT848_RISC_SOL |
+				      BT848_RISC_EOL | bpl);
+	}
+
 	/* scan lines */
 	sg = sglist;
-	for (line = 0; line < lines; line++) {
+	for (line = 0; line < store_lines; line++) {
 		if ((btv->opt_vcr_hack) &&
-		    (line >= (lines - VCR_HACK_LINES)))
+		    (line >= (store_lines - VCR_HACK_LINES)))
 			continue;
 		while (offset && offset >= sg_dma_len(sg)) {
 			offset -= sg_dma_len(sg);
@@ -130,7 +138,8 @@ bttv_risc_planar(struct bttv *btv, struct btcx_riscmem *risc,
 	/* estimate risc mem: worst case is one write per page border +
 	   one write per scan line (5 dwords)
 	   plus sync + jump (2 dwords) */
-	instructions  = (ybpl * ylines * 2) / PAGE_SIZE + ylines;
+	instructions  = ((3 + (ybpl + ypadding) * ylines * 2)
+			 / PAGE_SIZE) + ylines;
 	instructions += 2;
 	if ((rc = btcx_riscmem_alloc(btv->c.pci,risc,instructions*4*5)) < 0)
 		return rc;
@@ -317,10 +326,10 @@ bttv_risc_overlay(struct bttv *btv, struct btcx_riscmem *risc,
 /* ---------------------------------------------------------- */
 
 static void
-bttv_calc_geo(struct bttv *btv, struct bttv_geometry *geo,
-	      int width, int height, int interleaved, int norm)
+bttv_calc_geo_old(struct bttv *btv, struct bttv_geometry *geo,
+		  int width, int height, int interleaved,
+		  const struct bttv_tvnorm *tvnorm)
 {
-	const struct bttv_tvnorm *tvnorm = &bttv_tvnorms[norm];
 	u32 xsf, sr;
 	int vdelay;
 
@@ -361,6 +370,62 @@ bttv_calc_geo(struct bttv *btv, struct bttv_geometry *geo,
 }
 
 static void
+bttv_calc_geo		(struct bttv *                  btv,
+			 struct bttv_geometry *         geo,
+			 unsigned int                   width,
+			 unsigned int                   height,
+			 int                            both_fields,
+			 const struct bttv_tvnorm *     tvnorm,
+			 const struct v4l2_rect *       crop)
+{
+	unsigned int c_width;
+	unsigned int c_height;
+	u32 sr;
+
+	if ((crop->left == tvnorm->cropcap.defrect.left
+	     && crop->top == tvnorm->cropcap.defrect.top
+	     && crop->width == tvnorm->cropcap.defrect.width
+	     && crop->height == tvnorm->cropcap.defrect.height
+	     && width <= tvnorm->swidth /* see PAL-Nc et al */)
+	    || bttv_tvcards[btv->c.type].muxsel[btv->input] < 0) {
+		bttv_calc_geo_old(btv, geo, width, height,
+				  both_fields, tvnorm);
+		return;
+	}
+
+	/* For bug compatibility the image size checks permit scale
+	   factors > 16. See bttv_crop_calc_limits(). */
+	c_width = min((unsigned int) crop->width, width * 16);
+	c_height = min((unsigned int) crop->height, height * 16);
+
+	geo->width = width;
+	geo->hscale = (c_width * 4096U + (width >> 1)) / width - 4096;
+	/* Even to store Cb first, odd for Cr. */
+	geo->hdelay = ((crop->left * width + c_width) / c_width) & ~1;
+
+	geo->sheight = c_height;
+	geo->vdelay = crop->top - tvnorm->cropcap.bounds.top + MIN_VDELAY;
+	sr = c_height >> !both_fields;
+	sr = (sr * 512U + (height >> 1)) / height - 512;
+	geo->vscale = (0x10000UL - sr) & 0x1fff;
+	geo->vscale |= both_fields ? (BT848_VSCALE_INT << 8) : 0;
+	geo->vtotal = tvnorm->vtotal;
+
+	geo->crop = (((geo->width   >> 8) & 0x03) |
+		     ((geo->hdelay  >> 6) & 0x0c) |
+		     ((geo->sheight >> 4) & 0x30) |
+		     ((geo->vdelay  >> 2) & 0xc0));
+
+	if (btv->opt_combfilter) {
+		geo->vtc  = (width < 193) ? 2 : ((width < 385) ? 1 : 0);
+		geo->comb = (width < 769) ? 1 : 0;
+	} else {
+		geo->vtc  = 0;
+		geo->comb = 0;
+	}
+}
+
+static void
 bttv_apply_geo(struct bttv *btv, struct bttv_geometry *geo, int odd)
 {
 	int off = odd ? 0x80 : 0x00;
@@ -522,16 +587,51 @@ int
 bttv_buffer_activate_vbi(struct bttv *btv,
 			 struct bttv_buffer *vbi)
 {
-	/* vbi capture */
+	struct btcx_riscmem *top;
+	struct btcx_riscmem *bottom;
+	int top_irq_flags;
+	int bottom_irq_flags;
+
+	top = NULL;
+	bottom = NULL;
+	top_irq_flags = 0;
+	bottom_irq_flags = 0;
+
 	if (vbi) {
+		unsigned int crop, vdelay;
+
 		vbi->vb.state = STATE_ACTIVE;
 		list_del(&vbi->vb.queue);
-		bttv_risc_hook(btv, RISC_SLOT_O_VBI, &vbi->top,    0);
-		bttv_risc_hook(btv, RISC_SLOT_E_VBI, &vbi->bottom, 4);
-	} else {
-		bttv_risc_hook(btv, RISC_SLOT_O_VBI, NULL, 0);
-		bttv_risc_hook(btv, RISC_SLOT_E_VBI, NULL, 0);
+
+		/* VDELAY is start of video, end of VBI capturing. */
+		crop = btread(BT848_E_CROP);
+		vdelay = btread(BT848_E_VDELAY_LO) + ((crop & 0xc0) << 2);
+
+		if (vbi->geo.vdelay > vdelay) {
+			vdelay = vbi->geo.vdelay & 0xfe;
+			crop = (crop & 0x3f) | ((vbi->geo.vdelay >> 2) & 0xc0);
+
+			btwrite(vdelay, BT848_E_VDELAY_LO);
+			btwrite(crop,	BT848_E_CROP);
+			btwrite(vdelay, BT848_O_VDELAY_LO);
+			btwrite(crop,	BT848_O_CROP);
+		}
+
+		if (vbi->vbi_count[0] > 0) {
+			top = &vbi->top;
+			top_irq_flags = 4;
+		}
+
+		if (vbi->vbi_count[1] > 0) {
+			top_irq_flags = 0;
+			bottom = &vbi->bottom;
+			bottom_irq_flags = 4;
+		}
 	}
+
+	bttv_risc_hook(btv, RISC_SLOT_O_VBI, top, top_irq_flags);
+	bttv_risc_hook(btv, RISC_SLOT_E_VBI, bottom, bottom_irq_flags);
+
 	return 0;
 }
 
@@ -611,28 +711,31 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 		int bpf = bpl * (buf->vb.height >> 1);
 
 		bttv_calc_geo(btv,&buf->geo,buf->vb.width,buf->vb.height,
-			      V4L2_FIELD_HAS_BOTH(buf->vb.field),buf->tvnorm);
+			      V4L2_FIELD_HAS_BOTH(buf->vb.field),
+			      tvnorm,&buf->crop);
 
 		switch (buf->vb.field) {
 		case V4L2_FIELD_TOP:
 			bttv_risc_packed(btv,&buf->top,buf->vb.dma.sglist,
-					 0,bpl,0,buf->vb.height);
+					 /* offset */ 0,bpl,
+					 /* padding */ 0,/* skip_lines */ 0,
+					 buf->vb.height);
 			break;
 		case V4L2_FIELD_BOTTOM:
 			bttv_risc_packed(btv,&buf->bottom,buf->vb.dma.sglist,
-					 0,bpl,0,buf->vb.height);
+					 0,bpl,0,0,buf->vb.height);
 			break;
 		case V4L2_FIELD_INTERLACED:
 			bttv_risc_packed(btv,&buf->top,buf->vb.dma.sglist,
-					 0,bpl,bpl,buf->vb.height >> 1);
+					 0,bpl,bpl,0,buf->vb.height >> 1);
 			bttv_risc_packed(btv,&buf->bottom,buf->vb.dma.sglist,
-					 bpl,bpl,bpl,buf->vb.height >> 1);
+					 bpl,bpl,bpl,0,buf->vb.height >> 1);
 			break;
 		case V4L2_FIELD_SEQ_TB:
 			bttv_risc_packed(btv,&buf->top,buf->vb.dma.sglist,
-					 0,bpl,0,buf->vb.height >> 1);
+					 0,bpl,0,0,buf->vb.height >> 1);
 			bttv_risc_packed(btv,&buf->bottom,buf->vb.dma.sglist,
-					 bpf,bpl,0,buf->vb.height >> 1);
+					 bpf,bpl,0,0,buf->vb.height >> 1);
 			break;
 		default:
 			BUG();
@@ -662,7 +765,8 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 		switch (buf->vb.field) {
 		case V4L2_FIELD_TOP:
 			bttv_calc_geo(btv,&buf->geo,buf->vb.width,
-				      buf->vb.height,0,buf->tvnorm);
+				      buf->vb.height,/* both_fields */ 0,
+				      tvnorm,&buf->crop);
 			bttv_risc_planar(btv, &buf->top, buf->vb.dma.sglist,
 					 0,buf->vb.width,0,buf->vb.height,
 					 uoffset,voffset,buf->fmt->hshift,
@@ -670,7 +774,8 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 			break;
 		case V4L2_FIELD_BOTTOM:
 			bttv_calc_geo(btv,&buf->geo,buf->vb.width,
-				      buf->vb.height,0,buf->tvnorm);
+				      buf->vb.height,0,
+				      tvnorm,&buf->crop);
 			bttv_risc_planar(btv, &buf->bottom, buf->vb.dma.sglist,
 					 0,buf->vb.width,0,buf->vb.height,
 					 uoffset,voffset,buf->fmt->hshift,
@@ -678,7 +783,8 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 			break;
 		case V4L2_FIELD_INTERLACED:
 			bttv_calc_geo(btv,&buf->geo,buf->vb.width,
-				      buf->vb.height,1,buf->tvnorm);
+				      buf->vb.height,1,
+				      tvnorm,&buf->crop);
 			lines    = buf->vb.height >> 1;
 			ypadding = buf->vb.width;
 			cpadding = buf->vb.width >> buf->fmt->hshift;
@@ -700,7 +806,8 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 			break;
 		case V4L2_FIELD_SEQ_TB:
 			bttv_calc_geo(btv,&buf->geo,buf->vb.width,
-				      buf->vb.height,1,buf->tvnorm);
+				      buf->vb.height,1,
+				      tvnorm,&buf->crop);
 			lines    = buf->vb.height >> 1;
 			ypadding = buf->vb.width;
 			cpadding = buf->vb.width >> buf->fmt->hshift;
@@ -731,11 +838,12 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 		/* build risc code */
 		buf->vb.field = V4L2_FIELD_SEQ_TB;
 		bttv_calc_geo(btv,&buf->geo,tvnorm->swidth,tvnorm->sheight,
-			      1,buf->tvnorm);
+			      1,tvnorm,&buf->crop);
 		bttv_risc_packed(btv, &buf->top,  buf->vb.dma.sglist,
-				 0, RAW_BPL, 0, RAW_LINES);
+				 /* offset */ 0, RAW_BPL, /* padding */ 0,
+				 /* skip_lines */ 0, RAW_LINES);
 		bttv_risc_packed(btv, &buf->bottom, buf->vb.dma.sglist,
-				 buf->vb.size/2 , RAW_BPL, 0, RAW_LINES);
+				 buf->vb.size/2 , RAW_BPL, 0, 0, RAW_LINES);
 	}
 
 	/* copy format info */
@@ -761,7 +869,8 @@ bttv_overlay_risc(struct bttv *btv,
 
 	/* calculate geometry */
 	bttv_calc_geo(btv,&buf->geo,ov->w.width,ov->w.height,
-		      V4L2_FIELD_HAS_BOTH(ov->field), ov->tvnorm);
+		      V4L2_FIELD_HAS_BOTH(ov->field),
+		      &bttv_tvnorms[ov->tvnorm],&buf->crop);
 
 	/* build risc code */
 	switch (ov->field) {