[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>

1 files changed, 73 insertions, 1 deletions

diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
index b1817231f50c..ef1959bbd23f 100644
--- 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;
 }