drivers/video: Support ioctl(VIDIOC_QUERYCAP)

Support ioctl(VIDIOC_QUERYCAP) to get driver's name.

drivers/video/isx012.c

@@ -217,6 +217,7 @@ static bool is_movie_needed(uint8_t fmt, uint8_t fps);
 
 static int isx012_init(void);
 static int isx012_uninit(void);
+static const char *isx012_get_driver_name(void);
 static int isx012_validate_frame_setting(imgsensor_stream_type_t type,
                                          uint8_t nr_datafmt,
                                          FAR imgsensor_format_t *datafmts,
@@ -616,6 +617,7 @@ static struct imgsensor_ops_s g_isx012_ops =
 {
   isx012_init,                          /* init */
   isx012_uninit,                        /* uninit */
+  isx012_get_driver_name,               /* get driver name */
   isx012_validate_frame_setting,        /* validate_frame_setting */
   isx012_start_capture,                 /* start_capture */
   isx012_stop_capture,                  /* stop_capture */
@@ -1284,6 +1286,11 @@ static int isx012_uninit(void)
   return ret;
 }
 
+static const char *isx012_get_driver_name(void)
+{
+  return "ISX012";
+}
+
 static int8_t isx012_get_maximum_fps(uint8_t nr_fmt,
                                      FAR imgsensor_format_t *fmt)
 {

drivers/video/video.c

@@ -218,6 +218,7 @@ static int video_complete_capture(uint8_t  err_code, uint32_t datasize);
 
 /* internal function for each cmds of ioctl */
 
+static int video_querycap(FAR struct v4l2_capability *cap);
 static int video_reqbufs(FAR struct video_mng_s *vmng,
                          FAR struct v4l2_requestbuffers *reqbufs);
 static int video_qbuf(FAR struct video_mng_s *vmng,
@@ -989,6 +990,33 @@ static int video_close(FAR struct file *filep)
   return ret;
 }
 
+static int video_querycap(FAR struct v4l2_capability *cap)
+{
+  FAR const char *name;
+
+  ASSERT(g_video_sensor_ops);
+
+  if (cap == NULL)
+    {
+      return -EINVAL;
+    }
+
+  if (g_video_sensor_ops->get_driver_name == NULL)
+    {
+      return -ENOTTY;
+    }
+
+  name = g_video_sensor_ops->get_driver_name();
+
+  memset(cap, 0, sizeof(struct v4l2_capability));
+
+  /* cap->driver needs to be NULL-terminated. */
+
+  strlcpy((FAR char *)cap->driver, name, sizeof(cap->driver));
+
+  return OK;
+}
+
 static int video_reqbufs(FAR struct video_mng_s         *vmng,
                          FAR struct v4l2_requestbuffers *reqbufs)
 {
@@ -2657,6 +2685,11 @@ static int video_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
 
   switch (cmd)
     {
+      case VIDIOC_QUERYCAP:
+        ret = video_querycap((FAR struct v4l2_capability *)arg);
+
+        break;
+
       case VIDIOC_REQBUFS:
         ret = video_reqbufs(priv, (FAR struct v4l2_requestbuffers *)arg);
 

include/nuttx/video/imgsensor.h

@@ -305,7 +305,7 @@ struct imgsensor_ops_s
 {
   CODE int (*init)(void);
   CODE int (*uninit)(void);
-
+  CODE const char * (*get_driver_name)(void);
   CODE int (*validate_frame_setting)(imgsensor_stream_type_t type,
                                      uint8_t nr_datafmts,
                                      FAR imgsensor_format_t *datafmts,

include/nuttx/video/video.h

@@ -172,6 +172,12 @@ extern "C"
 
 #define V4SIOC_S_EXT_CTRLS_SCENE      _VIDIOC(0x001a)
 
+/* Query device capability
+ * Address pointing to struct v4l2_capability
+ */
+
+#define VIDIOC_QUERYCAP               _VIDIOC(0x001b)
+
 #define VIDEO_HSIZE_QVGA        (320)   /* QVGA    horizontal size */
 #define VIDEO_VSIZE_QVGA        (240)   /* QVGA    vertical   size */
 #define VIDEO_HSIZE_VGA         (640)   /* VGA     horizontal size */
@@ -238,6 +244,20 @@ extern "C"
  * Public Types
  ****************************************************************************/
 
+/* V4L2 device capabilities for VIDIOC_QUERYCAP.
+ * Currently, only member "driver" is supported.
+ */
+
+struct v4l2_capability
+{
+  uint8_t  driver[16];   /* name of driver module(e.g. "bttv" */
+  uint8_t  card[32];     /* name of the card(e.g. "Yoyodyne TV/FM" */
+  uint8_t  bus_info[32]; /* name of the bus(e.g. "PCI:0000:05:06.0" */
+  uint32_t version;      /* version number of the driver */
+  uint32_t capabilities; /* Available capabilities of the physical device */
+  uint32_t device_caps;  /* Device capabilities of the opened device */
+};
+
 /* Buffer type.
  *  Currently, support only V4L2_BUF_TYPE_VIDEO_CAPTURE and
  *  V4L2_BUF_TYPE_STILL_CAPTURE.