V4L/DVB (12741): em28xx: make video isoc stream work when VBI is enabled

Add code enabling the VBI registers for variants of the em28xx chip that
support VBI, and make sure the isoc streaming code continues to work for
the video component of the stream (note the video and vbi data arrive
intermixed on the same isoc pipe).

Note that this version just drops the actual VBI data onto the floor as
opposed to processing it.  The "#ifdef 0" tags are for the videobuf code that
appears in the next patch in this series.

We created a separate version of the isoc_copy version for parsing the version
of the stream that includes VBI data.  In theory, they might be able to be
merged at some point in the future, but the initial goal is to ensure that we
do not cause any regressions with devices that do not have VBI support.

This work was sponsored by EyeMagnet Limited.
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/em28xx/em28xx-core.c

@@ -54,6 +54,10 @@ static int alt = EM28XX_PINOUT;
 module_param(alt, int, 0644);
 MODULE_PARM_DESC(alt, "alternate setting to use for video endpoint");
 
+static unsigned int disable_vbi;
+module_param(disable_vbi, int, 0644);
+MODULE_PARM_DESC(disable_vbi, "disable vbi support");
+
 /* FIXME */
 #define em28xx_isocdbg(fmt, arg...) do {\
 	if (core_debug) \
@@ -648,9 +652,24 @@ int em28xx_capture_start(struct em28xx *dev, int start)
 	return rc;
 }
 
+int em28xx_vbi_supported(struct em28xx *dev)
+{
+	/* Modprobe option to manually disable */
+	if (disable_vbi == 1)
+		return 0;
+
+	if (dev->chip_id == CHIP_ID_EM2860 ||
+	    dev->chip_id == CHIP_ID_EM2883)
+		return 1;
+
+	/* Version of em28xx that does not support VBI */
+	return 0;
+}
+
 int em28xx_set_outfmt(struct em28xx *dev)
 {
 	int ret;
+	u8 vinctrl;
 
 	ret = em28xx_write_reg_bits(dev, EM28XX_R27_OUTFMT,
 				dev->format->reg | 0x20, 0xff);
@@ -661,7 +680,16 @@ int em28xx_set_outfmt(struct em28xx *dev)
 	if (ret < 0)
 		return ret;
 
-	return em28xx_write_reg(dev, EM28XX_R11_VINCTRL, dev->vinctl);
+	vinctrl = dev->vinctl;
+	if (em28xx_vbi_supported(dev) == 1) {
+		vinctrl |= EM28XX_VINCTRL_VBI_RAW;
+		em28xx_write_reg(dev, EM28XX_R34_VBI_START_H, 0x00);
+		em28xx_write_reg(dev, EM28XX_R35_VBI_START_V, 0x09);
+		em28xx_write_reg(dev, EM28XX_R36_VBI_WIDTH, 0xb4);
+		em28xx_write_reg(dev, EM28XX_R37_VBI_HEIGHT, 0x0c);
+	}
+
+	return em28xx_write_reg(dev, EM28XX_R11_VINCTRL, vinctrl);
 }
 
 static int em28xx_accumulator_set(struct em28xx *dev, u8 xmin, u8 xmax,
@@ -732,6 +760,13 @@ int em28xx_resolution_set(struct em28xx *dev)
 
 
 	em28xx_accumulator_set(dev, 1, (width - 4) >> 2, 1, (height - 4) >> 2);
+
+	/* If we don't set the start position to 4 in VBI mode, we end up
+	   with line 21 being YUYV encoded instead of being in 8-bit
+	   greyscale */
+	if (em28xx_vbi_supported(dev) == 1)
+		em28xx_capture_area_set(dev, 0, 4, width >> 2, height >> 2);
+	else
 		em28xx_capture_area_set(dev, 0, 0, width >> 2, height >> 2);
 
 	return em28xx_scaler_set(dev, dev->hscale, dev->vscale);
@@ -844,8 +879,7 @@ EXPORT_SYMBOL_GPL(em28xx_set_mode);
  */
 static void em28xx_irq_callback(struct urb *urb)
 {
-	struct em28xx_dmaqueue  *dma_q = urb->context;
-	struct em28xx *dev = container_of(dma_q, struct em28xx, vidq);
+	struct em28xx *dev = urb->context;
 	int rc, i;
 
 	switch (urb->status) {
@@ -994,7 +1028,7 @@ int em28xx_init_isoc(struct em28xx *dev, int max_packets,
 
 		usb_fill_int_urb(urb, dev->udev, pipe,
 				 dev->isoc_ctl.transfer_buffer[i], sb_size,
-				 em28xx_irq_callback, dma_q, 1);
+				 em28xx_irq_callback, dev, 1);
 
 		urb->number_of_packets = max_packets;
 		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;

drivers/media/video/em28xx/em28xx-reg.h

@@ -147,6 +147,10 @@
 #define EM28XX_R31_HSCALEHIGH	0x31
 #define EM28XX_R32_VSCALELOW	0x32
 #define EM28XX_R33_VSCALEHIGH	0x33
+#define EM28XX_R34_VBI_START_H	0x34
+#define EM28XX_R35_VBI_START_V	0x35
+#define EM28XX_R36_VBI_WIDTH	0x36
+#define EM28XX_R37_VBI_HEIGHT	0x37
 
 #define EM28XX_R40_AC97LSB	0x40
 #define EM28XX_R41_AC97MSB	0x41

drivers/media/video/em28xx/em28xx-video.c

@@ -329,7 +329,7 @@ static inline void get_next_buf(struct em28xx_dmaqueue *dma_q,
 static inline int em28xx_isoc_copy(struct em28xx *dev, struct urb *urb)
 {
 	struct em28xx_buffer    *buf;
-	struct em28xx_dmaqueue  *dma_q = urb->context;
+	struct em28xx_dmaqueue  *dma_q = &dev->vidq;
 	unsigned char *outp = NULL;
 	int i, len = 0, rc = 1;
 	unsigned char *p;
@@ -410,6 +410,118 @@ static inline int em28xx_isoc_copy(struct em28xx *dev, struct urb *urb)
 	return rc;
 }
 
+/* Version of isoc handler that takes into account a mixture of video and
+   VBI data */
+static inline int em28xx_isoc_copy_vbi(struct em28xx *dev, struct urb *urb)
+{
+	struct em28xx_buffer    *buf, *vbi_buf;
+	struct em28xx_dmaqueue  *dma_q = &dev->vidq;
+	unsigned char *outp = NULL;
+	unsigned char *vbioutp = NULL;
+	int i, len = 0, rc = 1;
+	unsigned char *p;
+	int vbi_size;
+
+	if (!dev)
+		return 0;
+
+	if ((dev->state & DEV_DISCONNECTED) || (dev->state & DEV_MISCONFIGURED))
+		return 0;
+
+	if (urb->status < 0) {
+		print_err_status(dev, -1, urb->status);
+		if (urb->status == -ENOENT)
+			return 0;
+	}
+
+	buf = dev->isoc_ctl.buf;
+	if (buf != NULL)
+		outp = videobuf_to_vmalloc(&buf->vb);
+	for (i = 0; i < urb->number_of_packets; i++) {
+		int status = urb->iso_frame_desc[i].status;
+
+		if (status < 0) {
+			print_err_status(dev, i, status);
+			if (urb->iso_frame_desc[i].status != -EPROTO)
+				continue;
+		}
+
+		len = urb->iso_frame_desc[i].actual_length - 4;
+
+		if (urb->iso_frame_desc[i].actual_length <= 0) {
+			/* em28xx_isocdbg("packet %d is empty",i); - spammy */
+			continue;
+		}
+		if (urb->iso_frame_desc[i].actual_length >
+						dev->max_pkt_size) {
+			em28xx_isocdbg("packet bigger than packet size");
+			continue;
+		}
+
+		p = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
+
+		/* capture type 0 = vbi start
+		   capture type 1 = video start
+		   capture type 2 = video in progress */
+		if (p[0] == 0x33 && p[1] == 0x95) {
+			dev->capture_type = 0;
+			dev->vbi_read = 0;
+			em28xx_isocdbg("VBI START HEADER!!!\n");
+			dev->cur_field = p[2];
+		}
+
+		/* FIXME: get rid of hard-coded value */
+		vbi_size = 720 * 0x0c;
+
+		if (dev->capture_type == 0) {
+			if (dev->vbi_read >= vbi_size) {
+				/* We've already read all the VBI data, so
+				   treat the rest as video */
+				printk("djh c should never happen\n");
+			} else if ((dev->vbi_read + len) < vbi_size) {
+				/* This entire frame is VBI data */
+				dev->vbi_read += len;
+			} else {
+				/* Some of this frame is VBI data and some is
+				   video data */
+				int vbi_data_len = vbi_size - dev->vbi_read;
+				dev->vbi_read += vbi_data_len;
+				dev->capture_type = 1;
+				p += vbi_data_len;
+				len -= vbi_data_len;
+			}
+		}
+
+		if (dev->capture_type == 1) {
+			dev->capture_type = 2;
+			em28xx_isocdbg("Video frame %d, length=%i, %s\n", p[2],
+				       len, (p[2] & 1) ? "odd" : "even");
+
+			if (dev->progressive || !(dev->cur_field & 1)) {
+				if (buf != NULL)
+					buffer_filled(dev, dma_q, buf);
+				get_next_buf(dma_q, &buf);
+				if (buf == NULL)
+					outp = NULL;
+				else
+					outp = videobuf_to_vmalloc(&buf->vb);
+			}
+			if (buf != NULL) {
+				if (dev->cur_field & 1)
+					buf->top_field = 0;
+				else
+					buf->top_field = 1;
+			}
+
+			dma_q->pos = 0;
+		}
+		if (buf != NULL && dev->capture_type == 2)
+			em28xx_copy_video(dev, dma_q, buf, p, outp, len);
+	}
+	return rc;
+}
+
+
 /* ------------------------------------------------------------------
 	Videobuf operations
    ------------------------------------------------------------------*/
@@ -494,8 +606,15 @@ buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
 		urb_init = 1;
 
 	if (urb_init) {
+		if (em28xx_vbi_supported(dev) == 1)
+			rc = em28xx_init_isoc(dev, EM28XX_NUM_PACKETS,
+					      EM28XX_NUM_BUFS,
+					      dev->max_pkt_size,
+					      em28xx_isoc_copy_vbi);
+		else
 			rc = em28xx_init_isoc(dev, EM28XX_NUM_PACKETS,
-				      EM28XX_NUM_BUFS, dev->max_pkt_size,
+					      EM28XX_NUM_BUFS,
+					      dev->max_pkt_size,
 					      em28xx_isoc_copy);
 		if (rc < 0)
 			goto fail;

drivers/media/video/em28xx/em28xx.h

@@ -544,6 +544,12 @@ struct em28xx {
 	enum em28xx_dev_state state;
 	enum em28xx_io_method io;
 
+	/* vbi related state tracking */
+	int capture_type;
+	int vbi_read;
+	unsigned char cur_field;
+
+
 	struct work_struct         request_module_wk;
 
 	/* locks */
@@ -639,6 +645,7 @@ int em28xx_audio_setup(struct em28xx *dev);
 
 int em28xx_colorlevels_set_default(struct em28xx *dev);
 int em28xx_capture_start(struct em28xx *dev, int start);
+int em28xx_vbi_supported(struct em28xx *dev);
 int em28xx_set_outfmt(struct em28xx *dev);
 int em28xx_resolution_set(struct em28xx *dev);
 int em28xx_set_alternate(struct em28xx *dev);