media: i2c: ov5647: Support HFLIP and VFLIP

Add these missing V4L2 controls. Tested binned and full resolution
modes in all four orientations using Raspberry Pi running libcamera.

Signed-off-by: David Plowman <david.plowman@raspberrypi.com>

drivers/media/i2c/ov5647.c

@@ -54,6 +54,8 @@
 #define OV5647_REG_GAIN_LO		0x350b
 #define OV5647_REG_VTS_HI		0x380e
 #define OV5647_REG_VTS_LO		0x380f
+#define OV5647_REG_VFLIP		0x3820
+#define OV5647_REG_HFLIP		0x3821
 #define OV5647_REG_FRAME_OFF_NUMBER	0x4202
 #define OV5647_REG_MIPI_CTRL00		0x4800
 #define OV5647_REG_MIPI_CTRL14		0x4814
@@ -109,6 +111,8 @@ struct ov5647 {
 	struct v4l2_ctrl		*hblank;
 	struct v4l2_ctrl		*vblank;
 	struct v4l2_ctrl		*exposure;
+	struct v4l2_ctrl		*hflip;
+	struct v4l2_ctrl		*vflip;
 };
 
 static inline struct ov5647 *to_sensor(struct v4l2_subdev *sd)
@@ -150,7 +154,7 @@ static struct regval_list ov5647_2592x1944_10bpp[] = {
 	{0x3036, 0x69},
 	{0x303c, 0x11},
 	{0x3106, 0xf5},
-	{0x3821, 0x06},
+	{0x3821, 0x00},
 	{0x3820, 0x00},
 	{0x3827, 0xec},
 	{0x370c, 0x03},
@@ -239,7 +243,7 @@ static struct regval_list ov5647_1080p30_10bpp[] = {
 	{0x3036, 0x62},
 	{0x303c, 0x11},
 	{0x3106, 0xf5},
-	{0x3821, 0x06},
+	{0x3821, 0x00},
 	{0x3820, 0x00},
 	{0x3827, 0xec},
 	{0x370c, 0x03},
@@ -403,7 +407,7 @@ static struct regval_list ov5647_2x2binned_10bpp[] = {
 	{0x4800, 0x24},
 	{0x3503, 0x03},
 	{0x3820, 0x41},
-	{0x3821, 0x07},
+	{0x3821, 0x01},
 	{0x350a, 0x00},
 	{0x350b, 0x10},
 	{0x3500, 0x00},
@@ -419,7 +423,7 @@ static struct regval_list ov5647_640x480_10bpp[] = {
 	{0x3035, 0x11},
 	{0x3036, 0x46},
 	{0x303c, 0x11},
-	{0x3821, 0x07},
+	{0x3821, 0x01},
 	{0x3820, 0x41},
 	{0x370c, 0x03},
 	{0x3612, 0x59},
@@ -948,6 +952,25 @@ static const struct v4l2_subdev_video_ops ov5647_subdev_video_ops = {
 	.s_stream =		ov5647_s_stream,
 };
 
+/* This function returns the mbus code for the current settings of the
+   HFLIP and VFLIP controls. */
+
+static u32 ov5647_get_mbus_code(struct v4l2_subdev *sd)
+{
+	struct ov5647 *sensor = to_sensor(sd);
+	/* The control values are only 0 or 1. */
+	int index =  sensor->hflip->val | (sensor->vflip->val << 1);
+
+	static const u32 codes[4] = {
+		MEDIA_BUS_FMT_SGBRG10_1X10,
+		MEDIA_BUS_FMT_SBGGR10_1X10,
+		MEDIA_BUS_FMT_SRGGB10_1X10,
+		MEDIA_BUS_FMT_SGRBG10_1X10
+	};
+
+	return codes[index];
+}
+
 static int ov5647_enum_mbus_code(struct v4l2_subdev *sd,
 				 struct v4l2_subdev_state *sd_state,
 				 struct v4l2_subdev_mbus_code_enum *code)
@@ -955,7 +978,7 @@ static int ov5647_enum_mbus_code(struct v4l2_subdev *sd,
 	if (code->index > 0)
 		return -EINVAL;
 
-	code->code = MEDIA_BUS_FMT_SBGGR10_1X10;
+	code->code = ov5647_get_mbus_code(sd);
 
 	return 0;
 }
@@ -966,7 +989,7 @@ static int ov5647_enum_frame_size(struct v4l2_subdev *sd,
 {
 	const struct v4l2_mbus_framefmt *fmt;
 
-	if (fse->code != MEDIA_BUS_FMT_SBGGR10_1X10 ||
+	if (fse->code != ov5647_get_mbus_code(sd) ||
 	    fse->index >= ARRAY_SIZE(ov5647_modes))
 		return -EINVAL;
 
@@ -999,6 +1022,8 @@ static int ov5647_get_pad_fmt(struct v4l2_subdev *sd,
 	}
 
 	*fmt = *sensor_format;
+	/* The code we pass back must reflect the current h/vflips. */
+	fmt->code = ov5647_get_mbus_code(sd);
 	mutex_unlock(&sensor->lock);
 
 	return 0;
@@ -1046,6 +1071,8 @@ static int ov5647_set_pad_fmt(struct v4l2_subdev *sd,
 					 exposure_def);
 	}
 	*fmt = mode->format;
+	/* The code we pass back must reflect the current h/vflips. */
+	fmt->code = ov5647_get_mbus_code(sd);
 	mutex_unlock(&sensor->lock);
 
 	return 0;
@@ -1221,6 +1248,25 @@ static int ov5647_s_exposure(struct v4l2_subdev *sd, u32 val)
 	return ov5647_write(sd, OV5647_REG_EXP_LO, (val & 0xf) << 4);
 }
 
+static int ov5647_s_flip( struct v4l2_subdev *sd, u16 reg, u32 ctrl_val)
+{
+	int ret;
+	u8 reg_val;
+
+	/* Set or clear bit 1 and leave everything else alone. */
+	ret = ov5647_read(sd, reg, &reg_val);
+	if (ret == 0) {
+		if (ctrl_val)
+			reg_val |= 2;
+		else
+			reg_val &= ~2;
+
+		ret = ov5647_write(sd, reg, reg_val);
+	}
+
+	return ret;
+}
+
 static int ov5647_s_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct ov5647 *sensor = container_of(ctrl->handler,
@@ -1283,6 +1329,14 @@ static int ov5647_s_ctrl(struct v4l2_ctrl *ctrl)
 		/* Read-only, but we adjust it based on mode. */
 		break;
 
+	case V4L2_CID_HFLIP:
+		/* There's an in-built hflip in the sensor, so account for that here. */
+		ov5647_s_flip(sd, OV5647_REG_HFLIP, !ctrl->val);
+		break;
+	case V4L2_CID_VFLIP:
+		ov5647_s_flip(sd, OV5647_REG_VFLIP, ctrl->val);
+		break;
+
 	default:
 		dev_info(&client->dev,
 			 "Control (id:0x%x, val:0x%x) not supported\n",
@@ -1354,6 +1408,16 @@ static int ov5647_init_controls(struct ov5647 *sensor, struct device *dev)
 				     ARRAY_SIZE(ov5647_test_pattern_menu) - 1,
 				     0, 0, ov5647_test_pattern_menu);
 
+	sensor->hflip = v4l2_ctrl_new_std(&sensor->ctrls, &ov5647_ctrl_ops,
+					  V4L2_CID_HFLIP, 0, 1, 1, 0);
+	if (sensor->hflip)
+		sensor->hflip->flags |= V4L2_CTRL_FLAG_MODIFY_LAYOUT;
+
+	sensor->vflip = v4l2_ctrl_new_std(&sensor->ctrls, &ov5647_ctrl_ops,
+					  V4L2_CID_VFLIP, 0, 1, 1, 0);
+	if (sensor->vflip)
+		sensor->vflip->flags |= V4L2_CTRL_FLAG_MODIFY_LAYOUT;
+
 	v4l2_fwnode_device_parse(dev, &props);
 
 	v4l2_ctrl_new_fwnode_properties(&sensor->ctrls, &ov5647_ctrl_ops,