media: i2c: adv7180: Add support for V4L2_CID_LINK_FREQ

For CSI2 receivers that need to know the link frequency,
add it as a control to the driver.
Interlaced modes are 216Mbp/s or 108MHz, whilst going through
the I2P to deinterlace gives 432Mb/s or 216MHz.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

drivers/media/i2c/adv7180.c

@@ -188,6 +188,16 @@
 /* Initial number of frames to skip to avoid possible garbage */
 #define ADV7180_NUM_OF_SKIP_FRAMES       2
 
+enum adv7180_link_freq_idx {
+	INTERLACED_IDX,
+	I2P_IDX,
+};
+
+static const s64 adv7180_link_freqs[] = {
+	[INTERLACED_IDX] = 108000000,
+	[I2P_IDX] = 216000000,
+};
+
 static int dbg_input;
 module_param(dbg_input, int, 0644);
 MODULE_PARM_DESC(dbg_input, "Input number (0-31)");
@@ -227,6 +237,7 @@ struct adv7180_state {
 	const struct adv7180_chip_info *chip_info;
 	enum v4l2_field		field;
 	bool			force_bt656_4;
+	struct v4l2_ctrl	*link_freq;
 };
 #define to_adv7180_sd(_ctrl) (&container_of(_ctrl->handler,		\
 					    struct adv7180_state,	\
@@ -681,7 +692,7 @@ static const struct v4l2_ctrl_config adv7180_ctrl_fast_switch = {
 
 static int adv7180_init_controls(struct adv7180_state *state)
 {
-	v4l2_ctrl_handler_init(&state->ctrl_hdl, 4);
+	v4l2_ctrl_handler_init(&state->ctrl_hdl, 5);
 
 	v4l2_ctrl_new_std(&state->ctrl_hdl, &adv7180_ctrl_ops,
 			  V4L2_CID_BRIGHTNESS, ADV7180_BRI_MIN,
@@ -703,6 +714,12 @@ static int adv7180_init_controls(struct adv7180_state *state)
 				      0, ARRAY_SIZE(test_pattern_menu) - 1,
 				      test_pattern_menu);
 
+	state->link_freq =
+		v4l2_ctrl_new_int_menu(&state->ctrl_hdl, &adv7180_ctrl_ops,
+				       V4L2_CID_LINK_FREQ,
+				       ARRAY_SIZE(adv7180_link_freqs) - 1, 0,
+				       adv7180_link_freqs);
+
 	state->sd.ctrl_handler = &state->ctrl_hdl;
 	if (state->ctrl_hdl.error) {
 		int err = state->ctrl_hdl.error;
@@ -835,6 +852,11 @@ static int adv7180_set_pad_format(struct v4l2_subdev *sd,
 			adv7180_set_power(state, false);
 			adv7180_set_field_mode(state);
 			adv7180_set_power(state, true);
+			if (state->chip_info->flags & ADV7180_FLAG_MIPI_CSI2) {
+				__v4l2_ctrl_s_ctrl(state->link_freq,
+						   state->field == V4L2_FIELD_NONE ?
+						   I2P_IDX : INTERLACED_IDX);
+			}
 		}
 	} else {
 		framefmt = v4l2_subdev_get_try_format(sd, sd_state, 0);