media: ov5645: Add control to export CSI2 link frequency

Add suport for standard integer menu V4L2_CID_LINK_FREQ control.
The CSI2 link frequency value is specific for each sensor mode so the
sensor mode structure is extended to add this. The control is made
read-only and its value is updated when the sensor mode is changed -
on set_format.

Signed-off-by: Todor Tomov <[e-mail]>
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/i2c/ov5645.c

···
 	const struct reg_value *data;
 	u32 data_size;
 	u32 pixel_clock;
+	u32 link_freq;
 };
 
 struct ov5645 {
···
 
 	struct v4l2_ctrl_handler ctrls;
 	struct v4l2_ctrl *pixel_clock;
+	struct v4l2_ctrl *link_freq;
 
 	/* Cached register values */
 	u8 aec_pk_manual;
···
 	{ 0x4202, 0x00 }
 };
 
+static const s64 link_freq[] = {
+	222880000,
+	334320000
+};
+
 static const struct ov5645_mode_info ov5645_mode_info_data[] = {
 	{
 		.width = 1280,
 		.height = 960,
 		.data = ov5645_setting_sxga,
 		.data_size = ARRAY_SIZE(ov5645_setting_sxga),
-		.pixel_clock = 111440000
+		.pixel_clock = 111440000,
+		.link_freq = 0 /* an index in link_freq[] */
 	},
 	{
 		.width = 1920,
 		.height = 1080,
 		.data = ov5645_setting_1080p,
 		.data_size = ARRAY_SIZE(ov5645_setting_1080p),
-		.pixel_clock = 167160000
+		.pixel_clock = 167160000,
+		.link_freq = 1 /* an index in link_freq[] */
 	},
 	{
 		.width = 2592,
 		.height = 1944,
 		.data = ov5645_setting_full,
 		.data_size = ARRAY_SIZE(ov5645_setting_full),
-		.pixel_clock = 167160000
+		.pixel_clock = 167160000,
+		.link_freq = 1 /* an index in link_freq[] */
 	},
 };
 
···
 		if (ret < 0)
 			return ret;
 
+		ret = v4l2_ctrl_s_ctrl(ov5645->link_freq,
+				       new_mode->link_freq);
+		if (ret < 0)
+			return ret;
+
 		ov5645->current_mode = new_mode;
 	}
 
···
 
 	mutex_init(&ov5645->power_lock);
 
-	v4l2_ctrl_handler_init(&ov5645->ctrls, 8);
+	v4l2_ctrl_handler_init(&ov5645->ctrls, 9);
 	v4l2_ctrl_new_std(&ov5645->ctrls, &ov5645_ctrl_ops,
 			  V4L2_CID_SATURATION, -4, 4, 1, 0);
 	v4l2_ctrl_new_std(&ov5645->ctrls, &ov5645_ctrl_ops,
···
 						&ov5645_ctrl_ops,
 						V4L2_CID_PIXEL_RATE,
 						1, INT_MAX, 1, 1);
+	ov5645->link_freq = v4l2_ctrl_new_int_menu(&ov5645->ctrls,
+						   &ov5645_ctrl_ops,
+						   V4L2_CID_LINK_FREQ,
+						   ARRAY_SIZE(link_freq) - 1,
+						   0, link_freq);
+	if (ov5645->link_freq)
+		ov5645->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
 
 	ov5645->sd.ctrl_handler = &ov5645->ctrls;