net: of_get_phy_mode: Change API to solve int/unit warnings

Before this change of_get_phy_mode() returned an enum,
phy_interface_t. On error, -ENODEV etc, is returned. If the result of
the function is stored in a variable of type phy_interface_t, and the
compiler has decided to represent this as an unsigned int, comparision
with -ENODEV etc, is a signed vs unsigned comparision.

Fix this problem by changing the API. Make the function return an
error, or 0 on success, and pass a pointer, of type phy_interface_t,
where the phy mode should be stored.

v2:
Return with *interface set to PHY_INTERFACE_MODE_NA on error.
Add error checks to all users of of_get_phy_mode()
Fixup a few reverse christmas tree errors
Fixup a few slightly malformed reverse christmas trees

v3:
Fix 0-day reported errors.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
index 0d21082ceb93..6ae13dc19510 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
@@ -189,9 +189,10 @@ static int ipq806x_gmac_set_speed(struct ipq806x_gmac *gmac, unsigned int speed)
 static int ipq806x_gmac_of_parse(struct ipq806x_gmac *gmac)
 {
 	struct device *dev = &gmac->pdev->dev;
+	int ret;
 
-	gmac->phy_mode = of_get_phy_mode(dev->of_node);
-	if ((int)gmac->phy_mode < 0) {
+	ret = of_get_phy_mode(dev->of_node, &gmac->phy_mode);
+	if (ret) {
 		dev_err(dev, "missing phy mode property\n");
 		return -EINVAL;
 	}