[media] em28xx: add support for em25xx/em276x/em277x/em278x frame data processing

The em25xx/em276x/em277x/em278x frame data format is different to the one used
by the em2710/em2750/em28xx chips.
With the recent cleanups and reorganization of the frame data processing code it
can be easily extended to support these devices.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
index b181723..ef1959b 100644 (file)
--- a/drivers/media/usb/em28xx/em28xx-video.c
+++ b/drivers/media/usb/em28xx/em28xx-video.c
@@ -76,6 +76,16 @@ MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 MODULE_VERSION(EM28XX_VERSION);
 
+
+#define EM25XX_FRMDATAHDR_BYTE1                        0x02
+#define EM25XX_FRMDATAHDR_BYTE2_STILL_IMAGE    0x20
+#define EM25XX_FRMDATAHDR_BYTE2_FRAME_END      0x02
+#define EM25XX_FRMDATAHDR_BYTE2_FRAME_ID       0x01
+#define EM25XX_FRMDATAHDR_BYTE2_MASK   (EM25XX_FRMDATAHDR_BYTE2_STILL_IMAGE | \
+                                        EM25XX_FRMDATAHDR_BYTE2_FRAME_END |   \
+                                        EM25XX_FRMDATAHDR_BYTE2_FRAME_ID)
+
+
 static unsigned int video_nr[] = {[0 ... (EM28XX_MAXBOARDS - 1)] = -1U };
 static unsigned int vbi_nr[]   = {[0 ... (EM28XX_MAXBOARDS - 1)] = -1U };
 static unsigned int radio_nr[] = {[0 ... (EM28XX_MAXBOARDS - 1)] = -1U };
@@ -408,6 +418,62 @@ static inline void process_frame_data_em28xx(struct em28xx *dev,
                em28xx_copy_video(dev, buf, data_pkt, data_len);
 }
 
+/*
+ * Process data packet according to the em25xx/em276x/7x/8x frame data format
+ */
+static inline void process_frame_data_em25xx(struct em28xx *dev,
+                                            unsigned char *data_pkt,
+                                            unsigned int  data_len)
+{
+       struct em28xx_buffer    *buf = dev->usb_ctl.vid_buf;
+       struct em28xx_dmaqueue  *dmaq = &dev->vidq;
+       bool frame_end = 0;
+
+       /* Check for header */
+       /* NOTE: at least with bulk transfers, only the first packet
+        * has a header and has always set the FRAME_END bit         */
+       if (data_len >= 2) {    /* em25xx header is only 2 bytes long */
+               if ((data_pkt[0] == EM25XX_FRMDATAHDR_BYTE1) &&
+                   ((data_pkt[1] & ~EM25XX_FRMDATAHDR_BYTE2_MASK) == 0x00)) {
+                       dev->top_field = !(data_pkt[1] &
+                                          EM25XX_FRMDATAHDR_BYTE2_FRAME_ID);
+                       frame_end = data_pkt[1] &
+                                   EM25XX_FRMDATAHDR_BYTE2_FRAME_END;
+                       data_pkt += 2;
+                       data_len -= 2;
+               }
+
+               /* Finish field and prepare next (BULK only) */
+               if (dev->analog_xfer_bulk && frame_end) {
+                       buf = finish_field_prepare_next(dev, buf, dmaq);
+                       dev->usb_ctl.vid_buf = buf;
+               }
+               /* NOTE: in ISOC mode when a new frame starts and buf==NULL,
+                * we COULD already prepare a buffer here to avoid skipping the
+                * first frame.
+                */
+       }
+
+       /* Copy data */
+       if (buf != NULL && data_len > 0)
+               em28xx_copy_video(dev, buf, data_pkt, data_len);
+
+       /* Finish frame (ISOC only) => avoids lag of 1 frame */
+       if (!dev->analog_xfer_bulk && frame_end) {
+               buf = finish_field_prepare_next(dev, buf, dmaq);
+               dev->usb_ctl.vid_buf = buf;
+       }
+
+       /* NOTE: Tested with USB bulk transfers only !
+        * The wording in the datasheet suggests that isoc might work different.
+        * The current code assumes that with isoc transfers each packet has a
+        * header like with the other em28xx devices.
+        */
+       /* NOTE: Support for interlaced mode is pure theory. It has not been
+        * tested and it is unknown if these devices actually support it. */
+       /* NOTE: No VBI support yet (these chips likely do not support VBI). */
+}
+
 /* Processes and copies the URB data content (video and VBI data) */
 static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb)
 {
@@ -460,7 +526,13 @@ static inline int em28xx_urb_data_copy(struct em28xx *dev, struct urb *urb)
                        continue;
                }
 
-               process_frame_data_em28xx(dev, usb_data_pkt, usb_data_len);
+               if (dev->is_em25xx)
+                       process_frame_data_em25xx(dev,
+                                                 usb_data_pkt, usb_data_len);
+               else
+                       process_frame_data_em28xx(dev,
+                                                 usb_data_pkt, usb_data_len);
+
        }
        return 1;
 }