media: rcar-csi2: update stream start for V3M

Latest errata document updates the start procedure for V3M. This change
in addition to adhering to the datasheet update fixes capture on early
revisions of V3M.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/rcar-vin/rcar-csi2.c

@@ -339,6 +339,7 @@ enum rcar_csi2_pads {
 
 struct rcar_csi2_info {
 	int (*init_phtw)(struct rcar_csi2 *priv, unsigned int mbps);
+	int (*confirm_start)(struct rcar_csi2 *priv);
 	const struct rcsi2_mbps_reg *hsfreqrange;
 	unsigned int csi0clkfreqrange;
 	bool clear_ulps;
@@ -545,6 +546,13 @@ static int rcsi2_start(struct rcar_csi2 *priv)
 	if (ret)
 		return ret;
 
+	/* Confirm start */
+	if (priv->info->confirm_start) {
+		ret = priv->info->confirm_start(priv);
+		if (ret)
+			return ret;
+	}
+
 	/* Clear Ultra Low Power interrupt. */
 	if (priv->info->clear_ulps)
 		rcsi2_write(priv, INTSTATE_REG,
@@ -880,6 +888,11 @@ static int rcsi2_init_phtw_h3_v3h_m3n(struct rcar_csi2 *priv, unsigned int mbps)
 }
 
 static int rcsi2_init_phtw_v3m_e3(struct rcar_csi2 *priv, unsigned int mbps)
+{
+	return rcsi2_phtw_write_mbps(priv, mbps, phtw_mbps_v3m_e3, 0x44);
+}
+
+static int rcsi2_confirm_start_v3m_e3(struct rcar_csi2 *priv)
 {
 	static const struct phtw_value step1[] = {
 		{ .data = 0xed, .code = 0x34 },
@@ -890,12 +903,6 @@ static int rcsi2_init_phtw_v3m_e3(struct rcar_csi2 *priv, unsigned int mbps)
 		{ /* sentinel */ },
 	};
 
-	int ret;
-
-	ret = rcsi2_phtw_write_mbps(priv, mbps, phtw_mbps_v3m_e3, 0x44);
-	if (ret)
-		return ret;
-
 	return rcsi2_phtw_write_array(priv, step1);
 }
 
@@ -949,6 +956,7 @@ static const struct rcar_csi2_info rcar_csi2_info_r8a77965 = {
 
 static const struct rcar_csi2_info rcar_csi2_info_r8a77970 = {
 	.init_phtw = rcsi2_init_phtw_v3m_e3,
+	.confirm_start = rcsi2_confirm_start_v3m_e3,
 };
 
 static const struct of_device_id rcar_csi2_of_table[] = {