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, 7 insertions, 2 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c
index e9fd661f7995..e1b63df6f96f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sti.c
@@ -116,7 +116,7 @@
 #define ETH_PHY_SEL_MII		0x0
 
 struct sti_dwmac {
-	int interface;		/* MII interface */
+	phy_interface_t interface;	/* MII interface */
 	bool ext_phyclk;	/* Clock from external PHY */
 	u32 tx_retime_src;	/* TXCLK Retiming*/
 	struct clk *clk;	/* PHY clock */
@@ -269,7 +269,12 @@ static int sti_dwmac_parse_data(struct sti_dwmac *dwmac,
 		return err;
 	}
 
-	dwmac->interface = of_get_phy_mode(np);
+	err = of_get_phy_mode(np, &dwmac->interface);
+	if (err && err != -ENODEV) {
+		dev_err(dev, "Can't get phy-mode\n");
+		return err;
+	}
+
 	dwmac->regmap = regmap;
 	dwmac->gmac_en = of_property_read_bool(np, "st,gmac_en");
 	dwmac->ext_phyclk = of_property_read_bool(np, "st,ext-phyclk");