[media] m5mols: Implement .get_frame_desc subdev callback

.get_frame_desc can be used by host interface driver to query
properties of captured frames, e.g. required memory buffer size.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/i2c/m5mols/m5mols.h

@@ -19,6 +19,13 @@
 #include <media/v4l2-subdev.h>
 #include "m5mols_reg.h"
 
+
+/* An amount of data transmitted in addition to the value
+ * determined by CAPP_JPEG_SIZE_MAX register.
+ */
+#define M5MOLS_JPEG_TAGS_SIZE		0x20000
+#define M5MOLS_MAIN_JPEG_SIZE_MAX	(5 * SZ_1M)
+
 extern int m5mols_debug;
 
 enum m5mols_restype {
@@ -67,12 +74,14 @@ struct m5mols_exif {
 /**
  * struct m5mols_capture - Structure for the capture capability
  * @exif: EXIF information
+ * @buf_size: internal JPEG frame buffer size, in bytes
  * @main: size in bytes of the main image
  * @thumb: size in bytes of the thumb image, if it was accompanied
  * @total: total size in bytes of the produced image
  */
 struct m5mols_capture {
 	struct m5mols_exif exif;
+	unsigned int buf_size;
 	u32 main;
 	u32 thumb;
 	u32 total;

drivers/media/i2c/m5mols/m5mols_capture.c

@@ -105,6 +105,7 @@ static int m5mols_capture_info(struct m5mols_info *info)
 
 int m5mols_start_capture(struct m5mols_info *info)
 {
+	unsigned int framesize = info->cap.buf_size - M5MOLS_JPEG_TAGS_SIZE;
 	struct v4l2_subdev *sd = &info->sd;
 	int ret;
 
@@ -120,6 +121,8 @@ int m5mols_start_capture(struct m5mols_info *info)
 		ret = m5mols_write(sd, CAPP_YUVOUT_MAIN, REG_JPEG);
 	if (!ret)
 		ret = m5mols_write(sd, CAPP_MAIN_IMAGE_SIZE, info->resolution);
+	if (!ret)
+		ret = m5mols_write(sd, CAPP_JPEG_SIZE_MAX, framesize);
 	if (!ret)
 		ret = m5mols_set_mode(info, REG_CAPTURE);
 	if (!ret)

drivers/media/i2c/m5mols/m5mols_core.c

@@ -599,6 +599,51 @@ static int m5mols_set_fmt(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
 	return ret;
 }
 
+static int m5mols_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+				 struct v4l2_mbus_frame_desc *fd)
+{
+	struct m5mols_info *info = to_m5mols(sd);
+
+	if (pad != 0 || fd == NULL)
+		return -EINVAL;
+
+	mutex_lock(&info->lock);
+	/*
+	 * .get_frame_desc is only used for compressed formats,
+	 * thus we always return the capture frame parameters here.
+	 */
+	fd->entry[0].length = info->cap.buf_size;
+	fd->entry[0].pixelcode = info->ffmt[M5MOLS_RESTYPE_CAPTURE].code;
+	mutex_unlock(&info->lock);
+
+	fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
+	fd->num_entries = 1;
+
+	return 0;
+}
+
+static int m5mols_set_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+				 struct v4l2_mbus_frame_desc *fd)
+{
+	struct m5mols_info *info = to_m5mols(sd);
+	struct v4l2_mbus_framefmt *mf = &info->ffmt[M5MOLS_RESTYPE_CAPTURE];
+
+	if (pad != 0 || fd == NULL)
+		return -EINVAL;
+
+	fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
+	fd->num_entries = 1;
+	fd->entry[0].length = clamp_t(u32, fd->entry[0].length,
+				      mf->width * mf->height,
+				      M5MOLS_MAIN_JPEG_SIZE_MAX);
+	mutex_lock(&info->lock);
+	info->cap.buf_size = fd->entry[0].length;
+	mutex_unlock(&info->lock);
+
+	return 0;
+}
+
+
 static int m5mols_enum_mbus_code(struct v4l2_subdev *sd,
 				 struct v4l2_subdev_fh *fh,
 				 struct v4l2_subdev_mbus_code_enum *code)
@@ -615,6 +660,8 @@ static struct v4l2_subdev_pad_ops m5mols_pad_ops = {
 	.enum_mbus_code	= m5mols_enum_mbus_code,
 	.get_fmt	= m5mols_get_fmt,
 	.set_fmt	= m5mols_set_fmt,
+	.get_frame_desc	= m5mols_get_frame_desc,
+	.set_frame_desc	= m5mols_set_frame_desc,
 };
 
 /**

drivers/media/i2c/m5mols/m5mols_reg.h

@@ -310,6 +310,7 @@
 #define REG_JPEG		0x10
 
 #define CAPP_MAIN_IMAGE_SIZE	I2C_REG(CAT_CAPT_PARM, 0x01, 1)
+#define CAPP_JPEG_SIZE_MAX	I2C_REG(CAT_CAPT_PARM, 0x0f, 4)
 #define CAPP_JPEG_RATIO		I2C_REG(CAT_CAPT_PARM, 0x17, 1)
 
 #define CAPP_MCC_MODE		I2C_REG(CAT_CAPT_PARM, 0x1d, 1)