[PATCH net-next v2 7/8] net: phy: dp83867: Validate FIFO depth property

[Trent Piepho]

Insure property is in valid range and fail when reading DT if it is not.
Also add error message for existing failure if required property is not
present.

Cc: Andrew Lunn <and...@lunn.ch>
Cc: Florian Fainelli <f.faine...@gmail.com>
Cc: Heiner Kallweit <hkallwe...@gmail.com>
Signed-off-by: Trent Piepho <tpie...@impinj.com>
---

Notes:
    Changes from v1:
      New patch in series v2

 drivers/net/phy/dp83867.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index 5ece153aa9c3..ce46ff4cf880 100644
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -65,7 +65,8 @@
 
 /* PHY CTRL bits */
 #define DP83867_PHYCR_FIFO_DEPTH_SHIFT         14
-#define DP83867_PHYCR_FIFO_DEPTH_MASK          (3 << 14)
+#define DP83867_PHYCR_FIFO_DEPTH_MAX           0x03
+#define DP83867_PHYCR_FIFO_DEPTH_MASK          GENMASK(15, 14)
 #define DP83867_PHYCR_RESERVED_MASK            BIT(11)
 
 /* RGMIIDCTL bits */
@@ -245,8 +246,20 @@ static int dp83867_of_init(struct phy_device *phydev)
        if (of_property_read_bool(of_node, "enet-phy-lane-no-swap"))
                dp83867->port_mirroring = DP83867_PORT_MIRROING_DIS;
 
-       return of_property_read_u32(of_node, "ti,fifo-depth",
+       ret = of_property_read_u32(of_node, "ti,fifo-depth",
                                   &dp83867->fifo_depth);
+       if (ret) {
+               phydev_err(phydev,
+                          "ti,fifo-depth property is required\n");
+               return ret;
+       }
+       if (dp83867->fifo_depth > DP83867_PHYCR_FIFO_DEPTH_MAX) {
+               phydev_err(phydev,
+                          "ti,fifo-depth value %u out of range\n",
+                          dp83867->fifo_depth);
+               return -EINVAL;
+       }
+       return 0;
 }
 #else
 static int dp83867_of_init(struct phy_device *phydev)
-- 
2.14.5