media: ti-vpe: cal: add camerarx enable/disable refcounting

The following patches add multistream support and we will have multiple
video devices using the same camerarx instances. Thus we need
enable/disable refcounting for the camerarx.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/ti-vpe/cal-camerarx.c

@@ -285,6 +285,11 @@ static int cal_camerarx_start(struct cal_camerarx *phy)
 	u32 val;
 	int ret;
 
+	if (phy->enable_count > 0) {
+		phy->enable_count++;
+		return 0;
+	}
+
 	link_freq = cal_camerarx_get_ext_link_freq(phy);
 	if (link_freq < 0)
 		return link_freq;
@@ -409,6 +414,8 @@ static int cal_camerarx_start(struct cal_camerarx *phy)
 	/* Finally, enable the PHY Protocol Interface (PPI). */
 	cal_camerarx_ppi_enable(phy);
 
+	phy->enable_count++;
+
 	return 0;
 }
 
@@ -416,6 +423,9 @@ static void cal_camerarx_stop(struct cal_camerarx *phy)
 {
 	int ret;
 
+	if (--phy->enable_count > 0)
+		return;
+
 	cal_camerarx_ppi_disable(phy);
 
 	cal_camerarx_disable_irqs(phy);

drivers/media/platform/ti-vpe/cal.h

@@ -167,8 +167,11 @@ struct cal_camerarx {
 	/*
 	 * Lock for camerarx ops. Protects:
 	 * - formats
+	 * - enable_count
 	 */
 	struct mutex		mutex;
+
+	unsigned int		enable_count;
 };
 
 struct cal_dev {