drm/bridge: anx7625: Use uint8 for lane-swing arrays

As defined in the anx7625 dt-binding, the analogix,lane0-swing and
analogix,lane1-swing properties are uint8 arrays. Yet, the driver was
reading the array as if it were of uint32 and masking to 8-bit before
writing to the registers. This means that a devicetree written in
accordance to the dt-binding would have its values incorrectly parsed.

Fix the issue by reading the array as uint8 and storing them as uint8
internally, so that we can also drop the masking when writing the
registers.

Fixes: fd0310b ("drm/bridge: anx7625: add MIPI DPI input feature")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220408013034.673418-1-nfraprado@collabora.com

drivers/gpu/drm/bridge/analogix/anx7625.c

@@ -1486,12 +1486,12 @@ static void anx7625_dp_adjust_swing(struct anx7625_data *ctx)
 	for (i = 0; i < ctx->pdata.dp_lane0_swing_reg_cnt; i++)
 		anx7625_reg_write(ctx, ctx->i2c.tx_p1_client,
 				  DP_TX_LANE0_SWING_REG0 + i,
-				  ctx->pdata.lane0_reg_data[i] & 0xFF);
+				  ctx->pdata.lane0_reg_data[i]);
 
 	for (i = 0; i < ctx->pdata.dp_lane1_swing_reg_cnt; i++)
 		anx7625_reg_write(ctx, ctx->i2c.tx_p1_client,
 				  DP_TX_LANE1_SWING_REG0 + i,
-				  ctx->pdata.lane1_reg_data[i] & 0xFF);
+				  ctx->pdata.lane1_reg_data[i]);
 }
 
 static void dp_hpd_change_handler(struct anx7625_data *ctx, bool on)
@@ -1598,8 +1598,8 @@ static int anx7625_get_swing_setting(struct device *dev,
 			num_regs = DP_TX_SWING_REG_CNT;
 
 		pdata->dp_lane0_swing_reg_cnt = num_regs;
-		of_property_read_u32_array(dev->of_node, "analogix,lane0-swing",
-					   pdata->lane0_reg_data, num_regs);
+		of_property_read_u8_array(dev->of_node, "analogix,lane0-swing",
+					  pdata->lane0_reg_data, num_regs);
 	}
 
 	if (of_get_property(dev->of_node,
@@ -1608,8 +1608,8 @@ static int anx7625_get_swing_setting(struct device *dev,
 			num_regs = DP_TX_SWING_REG_CNT;
 
 		pdata->dp_lane1_swing_reg_cnt = num_regs;
-		of_property_read_u32_array(dev->of_node, "analogix,lane1-swing",
-					   pdata->lane1_reg_data, num_regs);
+		of_property_read_u8_array(dev->of_node, "analogix,lane1-swing",
+					  pdata->lane1_reg_data, num_regs);
 	}
 
 	return 0;

drivers/gpu/drm/bridge/analogix/anx7625.h

@@ -426,9 +426,9 @@ struct anx7625_platform_data {
 	int mipi_lanes;
 	int audio_en;
 	int dp_lane0_swing_reg_cnt;
-	int lane0_reg_data[DP_TX_SWING_REG_CNT];
+	u8 lane0_reg_data[DP_TX_SWING_REG_CNT];
 	int dp_lane1_swing_reg_cnt;
-	int lane1_reg_data[DP_TX_SWING_REG_CNT];
+	u8 lane1_reg_data[DP_TX_SWING_REG_CNT];
 	u32 low_power_mode;
 	struct device_node *mipi_host_node;
 };