[PATCH 2/7] media: rcar-csi2: Allow writing any code and data value to PHTW

[Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>]

The helper to write an array of code and data values to the PHY Test
Interface Write Register (PHTW) register uses the case where both code
and data are zero as an exit condition. This prevents writing data = 0
and code = 0 to the register.

Up until now this has been OK as no such combination where needed, and
it was a convenient exit condition. In future writing data = 0 and code
= 0 to the PHTW register will be needed.

Avoid using an exit condition when writing an array of PHTW values and
instead pass the length of the array to the helper. This allows any
combination of code and data to be written.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
---
 drivers/media/platform/renesas/rcar-csi2.c | 29 ++++++++--------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/drivers/media/platform/renesas/rcar-csi2.c b/drivers/media/platform/renesas/rcar-csi2.c
index 6cc128990140..c02e1ec6600d 100644
--- a/drivers/media/platform/renesas/rcar-csi2.c
+++ b/drivers/media/platform/renesas/rcar-csi2.c
@@ -1447,13 +1447,13 @@ static int rcsi2_phtw_write(struct rcar_csi2 *priv, u8 data, u8 code)
 }
 
 static int rcsi2_phtw_write_array(struct rcar_csi2 *priv,
-				  const struct phtw_value *values)
+				  const struct phtw_value *values,
+				  unsigned int size)
 {
-	const struct phtw_value *value;
 	int ret;
 
-	for (value = values; value->data || value->code; value++) {
-		ret = rcsi2_phtw_write(priv, value->data, value->code);
+	for (unsigned int i = 0; i < size; i++) {
+		ret = rcsi2_phtw_write(priv, values[i].data, values[i].code);
 		if (ret)
 			return ret;
 	}
@@ -1494,7 +1494,6 @@ static int __rcsi2_init_phtw_h3_v3h_m3n(struct rcar_csi2 *priv,
 		{ .data = 0x11, .code = 0xe4 },
 		{ .data = 0x01, .code = 0xe5 },
 		{ .data = 0x10, .code = 0x04 },
-		{ /* sentinel */ },
 	};
 
 	static const struct phtw_value step2[] = {
@@ -1503,12 +1502,11 @@ static int __rcsi2_init_phtw_h3_v3h_m3n(struct rcar_csi2 *priv,
 		{ .data = 0x4b, .code = 0xac },
 		{ .data = 0x03, .code = 0x00 },
 		{ .data = 0x80, .code = 0x07 },
-		{ /* sentinel */ },
 	};
 
 	int ret;
 
-	ret = rcsi2_phtw_write_array(priv, step1);
+	ret = rcsi2_phtw_write_array(priv, step1, ARRAY_SIZE(step1));
 	if (ret)
 		return ret;
 
@@ -1523,7 +1521,7 @@ static int __rcsi2_init_phtw_h3_v3h_m3n(struct rcar_csi2 *priv,
 			return ret;
 	}
 
-	return rcsi2_phtw_write_array(priv, step2);
+	return rcsi2_phtw_write_array(priv, step2, ARRAY_SIZE(step2));
 }
 
 static int rcsi2_init_phtw_h3_v3h_m3n(struct rcar_csi2 *priv, unsigned int mbps)
@@ -1549,10 +1547,9 @@ static int rcsi2_phy_post_init_v3m_e3(struct rcar_csi2 *priv)
 		{ .data = 0xee, .code = 0x54 },
 		{ .data = 0xee, .code = 0x84 },
 		{ .data = 0xee, .code = 0x94 },
-		{ /* sentinel */ },
 	};
 
-	return rcsi2_phtw_write_array(priv, step1);
+	return rcsi2_phtw_write_array(priv, step1, ARRAY_SIZE(step1));
 }
 
 static int rcsi2_init_phtw_v3u(struct rcar_csi2 *priv,
@@ -1561,20 +1558,17 @@ static int rcsi2_init_phtw_v3u(struct rcar_csi2 *priv,
 	/* In case of 1500Mbps or less */
 	static const struct phtw_value step1[] = {
 		{ .data = 0xcc, .code = 0xe2 },
-		{ /* sentinel */ },
 	};
 
 	static const struct phtw_value step2[] = {
 		{ .data = 0x01, .code = 0xe3 },
 		{ .data = 0x11, .code = 0xe4 },
 		{ .data = 0x01, .code = 0xe5 },
-		{ /* sentinel */ },
 	};
 
 	/* In case of 1500Mbps or less */
 	static const struct phtw_value step3[] = {
 		{ .data = 0x38, .code = 0x08 },
-		{ /* sentinel */ },
 	};
 
 	static const struct phtw_value step4[] = {
@@ -1582,29 +1576,28 @@ static int rcsi2_init_phtw_v3u(struct rcar_csi2 *priv,
 		{ .data = 0x4b, .code = 0xac },
 		{ .data = 0x03, .code = 0x00 },
 		{ .data = 0x80, .code = 0x07 },
-		{ /* sentinel */ },
 	};
 
 	int ret;
 
 	if (mbps != 0 && mbps <= 1500)
-		ret = rcsi2_phtw_write_array(priv, step1);
+		ret = rcsi2_phtw_write_array(priv, step1, ARRAY_SIZE(step1));
 	else
 		ret = rcsi2_phtw_write_mbps(priv, mbps, phtw_mbps_v3u, 0xe2);
 	if (ret)
 		return ret;
 
-	ret = rcsi2_phtw_write_array(priv, step2);
+	ret = rcsi2_phtw_write_array(priv, step2, ARRAY_SIZE(step2));
 	if (ret)
 		return ret;
 
 	if (mbps != 0 && mbps <= 1500) {
-		ret = rcsi2_phtw_write_array(priv, step3);
+		ret = rcsi2_phtw_write_array(priv, step3, ARRAY_SIZE(step3));
 		if (ret)
 			return ret;
 	}
 
-	ret = rcsi2_phtw_write_array(priv, step4);
+	ret = rcsi2_phtw_write_array(priv, step4, ARRAY_SIZE(step4));
 	if (ret)
 		return ret;
 
-- 
2.45.1