[PATCH v2] media: ov5640: add JPEG support

[Hugues Fruchet <hugues.fruchet@xxxxxx>]

Add YUV422 encoded JPEG support.

Signed-off-by: Hugues Fruchet <hugues.fruchet@xxxxxx>
---
version 2:
  - Revisit code as per Sakari suggestions:
    - fix lock scheme
    - fix switch back to non-JPEG output while sensor powered
    See https://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg124979.html

 drivers/media/i2c/ov5640.c | 90 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 88 insertions(+), 2 deletions(-)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index e2dd352..faa4502 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -18,6 +18,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
+#include <linux/sizes.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/gpio/consumer.h>
@@ -34,6 +35,10 @@
 
 #define OV5640_DEFAULT_SLAVE_ID 0x3c
 
+#define OV5640_JPEG_SIZE_MAX (5 * SZ_1M)
+
+#define OV5640_REG_SYS_RESET02		0x3002
+#define OV5640_REG_SYS_CLOCK_ENABLE02	0x3006
 #define OV5640_REG_SYS_CTRL0		0x3008
 #define OV5640_REG_CHIP_ID		0x300a
 #define OV5640_REG_IO_MIPI_CTRL00	0x300e
@@ -114,6 +119,7 @@ struct ov5640_pixfmt {
 };
 
 static const struct ov5640_pixfmt ov5640_formats[] = {
+	{ MEDIA_BUS_FMT_JPEG_1X8, V4L2_COLORSPACE_JPEG, },
 	{ MEDIA_BUS_FMT_UYVY8_2X8, V4L2_COLORSPACE_SRGB, },
 	{ MEDIA_BUS_FMT_YUYV8_2X8, V4L2_COLORSPACE_SRGB, },
 	{ MEDIA_BUS_FMT_RGB565_2X8_LE, V4L2_COLORSPACE_SRGB, },
@@ -220,6 +226,8 @@ struct ov5640_dev {
 
 	bool pending_mode_change;
 	bool streaming;
+
+	unsigned int jpeg_size;
 };
 
 static inline struct ov5640_dev *to_ov5640_dev(struct v4l2_subdev *sd)
@@ -1910,11 +1918,50 @@ static int ov5640_set_fmt(struct v4l2_subdev *sd,
 	return ret;
 }
 
+static int ov5640_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+				 struct v4l2_mbus_frame_desc *fd)
+{
+	struct ov5640_dev *sensor = to_ov5640_dev(sd);
+
+	if (pad != 0 || !fd)
+		return -EINVAL;
+
+	mutex_lock(&sensor->lock);
+	fd->entry[0].length = sensor->jpeg_size;
+	mutex_unlock(&sensor->lock);
+	fd->entry[0].pixelcode = MEDIA_BUS_FMT_JPEG_1X8;
+	fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
+	fd->num_entries = 1;
+
+	return 0;
+}
+
+static int ov5640_set_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
+				 struct v4l2_mbus_frame_desc *fd)
+{
+	struct ov5640_dev *sensor = to_ov5640_dev(sd);
+
+	if (pad != 0 || !fd)
+		return -EINVAL;
+
+	fd->entry[0].flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
+	fd->num_entries = 1;
+	mutex_lock(&sensor->lock);
+	fd->entry[0].length = clamp_t(u32, fd->entry[0].length,
+				      sensor->fmt.width * sensor->fmt.height,
+				      OV5640_JPEG_SIZE_MAX);
+	sensor->jpeg_size = fd->entry[0].length;
+	mutex_unlock(&sensor->lock);
+
+	return 0;
+}
+
 static int ov5640_set_framefmt(struct ov5640_dev *sensor,
 			       struct v4l2_mbus_framefmt *format)
 {
 	int ret = 0;
 	bool is_rgb = false;
+	bool is_jpeg = false;
 	u8 val;
 
 	switch (format->code) {
@@ -1936,6 +1983,11 @@ static int ov5640_set_framefmt(struct ov5640_dev *sensor,
 		val = 0x61;
 		is_rgb = true;
 		break;
+	case MEDIA_BUS_FMT_JPEG_1X8:
+		/* YUV422, YUYV */
+		val = 0x30;
+		is_jpeg = true;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -1946,8 +1998,40 @@ static int ov5640_set_framefmt(struct ov5640_dev *sensor,
 		return ret;
 
 	/* FORMAT MUX CONTROL: ISP YUV or RGB */
-	return ov5640_write_reg(sensor, OV5640_REG_ISP_FORMAT_MUX_CTRL,
-				is_rgb ? 0x01 : 0x00);
+	ret = ov5640_write_reg(sensor, OV5640_REG_ISP_FORMAT_MUX_CTRL,
+			       is_rgb ? 0x01 : 0x00);
+	if (ret)
+		return ret;
+
+	/*
+	 * TIMING TC REG21:
+	 * - [5]:	JPEG enable
+	 */
+	ret = ov5640_mod_reg(sensor, OV5640_REG_TIMING_TC_REG21,
+			     BIT(5), is_jpeg ? BIT(5) : 0);
+	if (ret)
+		return ret;
+
+	/*
+	 * SYSTEM RESET02:
+	 * - [4]:	Reset JFIFO
+	 * - [3]:	Reset SFIFO
+	 * - [2]:	Reset JPEG
+	 */
+	ret = ov5640_mod_reg(sensor, OV5640_REG_SYS_RESET02,
+			     BIT(4) | BIT(3) | BIT(2),
+			     is_jpeg ? 0 : (BIT(4) | BIT(3) | BIT(2)));
+	if (ret)
+		return ret;
+
+	/*
+	 * CLOCK ENABLE02:
+	 * - [5]:	Enable JPEG 2x clock
+	 * - [3]:	Enable JPEG clock
+	 */
+	return ov5640_mod_reg(sensor, OV5640_REG_SYS_CLOCK_ENABLE02,
+			      BIT(5) | BIT(3),
+			      is_jpeg ? (BIT(5) | BIT(3)) : 0);
 }
 
 /*
@@ -2391,6 +2475,8 @@ static int ov5640_s_stream(struct v4l2_subdev *sd, int enable)
 	.set_fmt = ov5640_set_fmt,
 	.enum_frame_size = ov5640_enum_frame_size,
 	.enum_frame_interval = ov5640_enum_frame_interval,
+	.get_frame_desc	= ov5640_get_frame_desc,
+	.set_frame_desc	= ov5640_set_frame_desc,
 };
 
 static const struct v4l2_subdev_ops ov5640_subdev_ops = {
-- 
1.9.1