phy: cadence-torrent: Check total lane count for all subnodes is within limit

Add checking if total number of lanes for all subnodes is not greater than
number of lanes supported by PHY.
Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
Link: https://lore.kernel.org/r/1600280911-9214-6-git-send-email-sjakhade@cadence.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/cadence/phy-cadence-torrent.c

@@ -25,7 +25,6 @@
 #define REF_CLK_19_2MHz		19200000
 #define REF_CLK_25MHz		25000000
 
-#define DEFAULT_NUM_LANES	4
 #define MAX_NUM_LANES		4
 #define DEFAULT_MAX_BIT_RATE	8100 /* in Mbps */
 
@@ -1734,6 +1733,7 @@ static int cdns_torrent_phy_probe(struct platform_device *pdev)
 	const struct cdns_torrent_data *data;
 	struct device_node *child;
 	int ret, subnodes, node = 0, i;
+	u32 total_num_lanes = 0;
 	u8 init_dp_regmap = 0;
 
 	/* Get init data for this PHY */
@@ -1808,9 +1808,15 @@ static int cdns_torrent_phy_probe(struct platform_device *pdev)
 			goto put_child;
 		}
 
-		cdns_phy->phys[node].num_lanes = DEFAULT_NUM_LANES;
-		of_property_read_u32(child, "cdns,num-lanes",
-				     &cdns_phy->phys[node].num_lanes);
+		if (of_property_read_u32(child, "cdns,num-lanes",
+					 &cdns_phy->phys[node].num_lanes)) {
+			dev_err(dev, "%s: No \"cdns,num-lanes\"-property.\n",
+				child->full_name);
+			ret = -EINVAL;
+			goto put_child;
+		}
+
+		total_num_lanes += cdns_phy->phys[node].num_lanes;
 
 		if (cdns_phy->phys[node].phy_type == PHY_TYPE_DP) {
 			switch (cdns_phy->phys[node].num_lanes) {
@@ -1890,6 +1896,11 @@ static int cdns_torrent_phy_probe(struct platform_device *pdev)
 	}
 	cdns_phy->nsubnodes = node;
 
+	if (total_num_lanes > MAX_NUM_LANES) {
+		dev_err(dev, "Invalid lane configuration\n");
+		goto put_lnk_rst;
+	}
+
 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 	if (IS_ERR(phy_provider)) {
 		ret = PTR_ERR(phy_provider);