From: "Jan Petrous (OSS)" <jan.petrous@oss.nxp.com>
The RGMII interface supports three data rates: 10/100 Mbps
and 1 Gbps. These speeds correspond to clock frequencies
of 2.5/25 MHz and 125 MHz, respectively.
Many Ethernet drivers, including glues in stmmac, follow
a similar pattern of converting RGMII speed to clock frequency.
To simplify code, define the helper rgmii_clock(speed)
to convert connection speed to clock frequency.
Suggested-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jan Petrous (OSS) <jan.petrous@oss.nxp.com>
---
include/linux/phy.h | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/include/linux/phy.h b/include/linux/phy.h
index a98bc91a0cde..e28c971d7616 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -298,6 +298,29 @@ static inline const char *phy_modes(phy_interface_t interface)
}
}
+/**
+ * rgmii_clock - map link speed to the clock rate
+ * @speed: link speed value
+ *
+ * Description: maps RGMII supported link speeds
+ * into the clock rates.
+ *
+ * Returns: clock rate or negative errno
+ */
+static inline long rgmii_clock(int speed)
+{
+ switch (speed) {
+ case SPEED_10:
+ return 2500000;
+ case SPEED_100:
+ return 25000000;
+ case SPEED_1000:
+ return 125000000;
+ default:
+ return -EINVAL;
+ }
+}
+
#define PHY_INIT_TIMEOUT 100000
#define PHY_FORCE_TIMEOUT 10
--
2.47.0