media: rcar-vin: Cache the CSI-2 channel selection value

In preparation of suspend/resume support cache the chsel value when
written to the register so it can be restored on resume if needed.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/rcar-vin/rcar-dma.c

@@ -1456,6 +1456,8 @@ int rvin_set_channel_routing(struct rvin_dev *vin, u8 chsel)
 
 	vin_dbg(vin, "Set IFMD 0x%x\n", ifmd);
 
+	vin->chsel = chsel;
+
 	/* Restore VNMC. */
 	rvin_write(vin, vnmc, VNMC_REG);
 

drivers/media/platform/rcar-vin/rcar-vin.h

@@ -189,6 +189,7 @@ struct rvin_info {
  * @state:		keeps track of operation state
  *
  * @is_csi:		flag to mark the VIN as using a CSI-2 subdevice
+ * @chsel		Cached value of the current CSI-2 channel selection
  *
  * @mbus_code:		media bus format code
  * @format:		active V4L2 pixel format
@@ -232,6 +233,7 @@ struct rvin_dev {
 	enum rvin_dma_state state;
 
 	bool is_csi;
+	unsigned int chsel;
 
 	u32 mbus_code;
 	struct v4l2_pix_format format;