media: i2c: imx290: Support 60fps in 2 lane operation

Commit "97589ad6 media: i2c: imx290: Add support for 2 data lanes"
added support for running in two lane mode (instead of 4), but
without changing the link frequency that resulted in a max of 30fps.

Commit "98e0500e media: i2c: imx290: Add configurable link frequency
and pixel rate" then doubled the link frequency when in 2 lane mode,
but didn't undo the correction for running at only 30fps, just extending
horizontal blanking instead.

Remove the 30fps limit on 2 lane by correcting the register config
in accordance with the datasheet for 60fps operation over 2 lanes.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/i2c/imx290.c

@@ -385,7 +385,7 @@ static const struct imx290_mode imx290_modes_2lanes[] = {
 	{
 		.width = 1920,
 		.height = 1080,
-		.hmax = 4400,
+		.hmax = 2200,
 		.link_freq_index = FREQ_INDEX_1080P,
 		.data = imx290_1080p_settings,
 		.data_size = ARRAY_SIZE(imx290_1080p_settings),
@@ -393,7 +393,7 @@ static const struct imx290_mode imx290_modes_2lanes[] = {
 	{
 		.width = 1280,
 		.height = 720,
-		.hmax = 6600,
+		.hmax = 3300,
 		.link_freq_index = FREQ_INDEX_720P,
 		.data = imx290_720p_settings,
 		.data_size = ARRAY_SIZE(imx290_720p_settings),
@@ -544,21 +544,10 @@ static int imx290_set_register_array(struct imx290 *imx290,
 static int imx290_set_data_lanes(struct imx290 *imx290)
 {
 	int ret = 0;
-	u32 frsel;
-
-	switch (imx290->nlanes) {
-	case 2:
-	default:
-		frsel = 0x02;
-		break;
-	case 4:
-		frsel = 0x01;
-		break;
-	}
 
 	imx290_write(imx290, IMX290_PHY_LANE_NUM, imx290->nlanes - 1, &ret);
 	imx290_write(imx290, IMX290_CSI_LANE_MODE, imx290->nlanes - 1, &ret);
-	imx290_write(imx290, IMX290_FR_FDG_SEL, frsel, &ret);
+	imx290_write(imx290, IMX290_FR_FDG_SEL, 0x01, &ret);
 
 	return ret;
 }