drm: bridge: anx7625: Use of_property_read_variable_u8_array()

There's no need to get the length of an DT array property before
parsing the array. of_property_read_variable_u8_array() takes a minimum
and maximum length and returns the actual length (or error code).

This is part of a larger effort to remove callers of of_get_property()
and similar functions. of_get_property() leaks the DT property data
pointer which is a problem for dynamically allocated nodes which may
be freed.
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240731201407.1838385-4-robh@kernel.org

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

@@ -1647,25 +1647,15 @@ static int anx7625_get_swing_setting(struct device *dev,
 {
 	int num_regs;
 
-	if (of_get_property(dev->of_node,
-			    "analogix,lane0-swing", &num_regs)) {
-		if (num_regs > DP_TX_SWING_REG_CNT)
-			num_regs = DP_TX_SWING_REG_CNT;
-
+	num_regs = of_property_read_variable_u8_array(dev->of_node, "analogix,lane0-swing",
+						      pdata->lane0_reg_data, 1, DP_TX_SWING_REG_CNT);
+	if (num_regs > 0)
 		pdata->dp_lane0_swing_reg_cnt = 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,
-			    "analogix,lane1-swing", &num_regs)) {
-		if (num_regs > DP_TX_SWING_REG_CNT)
-			num_regs = DP_TX_SWING_REG_CNT;
 
+	num_regs = of_property_read_variable_u8_array(dev->of_node, "analogix,lane1-swing",
+						      pdata->lane1_reg_data, 1, DP_TX_SWING_REG_CNT);
+	if (num_regs > 0)
 		pdata->dp_lane1_swing_reg_cnt = num_regs;
-		of_property_read_u8_array(dev->of_node, "analogix,lane1-swing",
-					  pdata->lane1_reg_data, num_regs);
-	}
 
 	return 0;
 }