drivers/video/gc0308: add YUYV output format support

GC0308 sensor supports multiple output formats via register 0x24.
Add YUYV (YCbCr422) alongside existing RGB565 in fmtdescs and
configure the output format register dynamically in start_capture()
based on the requested pixel format.

Signed-off-by: wangjianyu3 <wangjianyu3@xiaomi.com>

Author: JianyuWang0623

drivers/video/gc0308.c

@@ -154,6 +154,7 @@ struct gc0308_dev_s
   struct i2c_master_s *i2c;
   uint16_t width;
   uint16_t height;
+  uint32_t pixelformat;
   struct v4l2_frmsizeenum frmsizes;
   bool streaming;
 };
@@ -455,6 +456,10 @@ static const struct imgsensor_ops_s g_gc0308_ops =
 
 static const struct v4l2_fmtdesc g_gc0308_fmtdescs[] =
 {
+  {
+    .pixelformat = V4L2_PIX_FMT_YUYV,
+    .description = "YUV 4:2:2 (YUYV)",
+  },
   {
     .pixelformat = V4L2_PIX_FMT_RGB565,
     .description = "RGB565",
@@ -648,7 +653,7 @@ static int gc0308_init(struct imgsensor_s *sensor)
 
   up_mdelay(80);
 
-  /* Set RGB565 output format: reg 0x24 bits[3:0] = 6 */
+  /* Set default RGB565 output format: reg 0x24 bits[3:0] = 6 */
 
   ret = gc0308_putreg(priv->i2c, GC0308_REG_RESET, 0x00);
   if (ret < 0)
@@ -657,6 +662,7 @@ static int gc0308_init(struct imgsensor_s *sensor)
     }
 
   ret = gc0308_modreg(priv->i2c, GC0308_REG_OUTPUT_FMT, 0x0f, 0x06);
+  priv->pixelformat = IMGSENSOR_PIX_FMT_RGB565;
   if (ret < 0)
     {
       return ret;
@@ -752,6 +758,8 @@ static int gc0308_validate_frame_setting(struct imgsensor_s *sensor,
     }
 
   if (datafmts[IMGSENSOR_FMT_MAIN].pixelformat !=
+      IMGSENSOR_PIX_FMT_YUYV &&
+      datafmts[IMGSENSOR_FMT_MAIN].pixelformat !=
       IMGSENSOR_PIX_FMT_RGB565)
     {
       return -EINVAL;
@@ -777,12 +785,32 @@ static int gc0308_start_capture(struct imgsensor_s *sensor,
                                 imgsensor_interval_t *interval)
 {
   struct gc0308_dev_s *priv = (struct gc0308_dev_s *)sensor;
+  uint8_t fmtval;
+  int ret;
 
   if (priv->streaming)
     {
       return -EBUSY;
     }
 
+  /* Configure output format register based on requested pixel format */
+
+  if (datafmts[IMGSENSOR_FMT_MAIN].pixelformat == IMGSENSOR_PIX_FMT_RGB565)
+    {
+      fmtval = 0x06;  /* RGB565 */
+    }
+  else
+    {
+      fmtval = 0x02;  /* YCbCr422 */
+    }
+
+  ret = gc0308_modreg(priv->i2c, GC0308_REG_OUTPUT_FMT, 0x0f, fmtval);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
+  priv->pixelformat = datafmts[IMGSENSOR_FMT_MAIN].pixelformat;
   priv->streaming = true;
   return OK;
 }