diff mbox series

[v4,04/16] net: phy: Add helper for mapping RGMII link speed to clock rate

Message ID 20241028-upstream_s32cc_gmac-v4-4-03618f10e3e2@oss.nxp.com (mailing list archive)
State New
Headers show
Series Add support for Synopsis DWMAC IP on NXP Automotive SoCs S32G2xx/S32G3xx/S32R45 | expand

Commit Message

Jan Petrous via B4 Relay Oct. 28, 2024, 8:24 p.m. UTC 
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>
Signed-off-by: Jan Petrous (OSS) <jan.petrous@oss.nxp.com>
---
 include/linux/phy.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

Comments

Andrew Lunn Oct. 29, 2024, 12:02 p.m. UTC | #1 
On Mon, Oct 28, 2024 at 09:24:46PM +0100, Jan Petrous via B4 Relay wrote:
> 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>
> Signed-off-by: Jan Petrous (OSS) <jan.petrous@oss.nxp.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew
diff mbox series

Patch

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