[PATCH net-next] net: phy: broadcom: Enable 125 MHz clock on LED4 pin for BCM54612E by default.

[Kun Yi <kunyi@google.com>]

BCM54612E have 4 multi-functional LED pins that can be configured
through register setting; the LED4 pin can be configured to a 125MHz
reference clock output by setting the spare register. Since the dedicated
CLK125 reference clock pin is not brought out on the 48-Pin MLP, the LED4
pin is the only pin to provide such function in this package, and therefore
it is beneficial to just enable the reference clock by default.

Signed-off-by: Kun Yi <kunyi@google.com>
---
 drivers/net/phy/broadcom.c | 16 ++++++++++++++--
 include/linux/brcmphy.h    |  4 ++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/broadcom.c b/drivers/net/phy/broadcom.c
index f9c25912eb98..e86ea105c802 100644
--- a/drivers/net/phy/broadcom.c
+++ b/drivers/net/phy/broadcom.c
@@ -54,6 +54,8 @@ static int bcm54210e_config_init(struct phy_device *phydev)
 
 static int bcm54612e_config_init(struct phy_device *phydev)
 {
+	int reg;
+
 	/* Clear TX internal delay unless requested. */
 	if ((phydev->interface != PHY_INTERFACE_MODE_RGMII_ID) &&
 	    (phydev->interface != PHY_INTERFACE_MODE_RGMII_TXID)) {
@@ -65,8 +67,6 @@ static int bcm54612e_config_init(struct phy_device *phydev)
 	/* Clear RX internal delay unless requested. */
 	if ((phydev->interface != PHY_INTERFACE_MODE_RGMII_ID) &&
 	    (phydev->interface != PHY_INTERFACE_MODE_RGMII_RXID)) {
-		u16 reg;
-
 		reg = bcm54xx_auxctl_read(phydev,
 					  MII_BCM54XX_AUXCTL_SHDWSEL_MISC);
 		/* Disable RXD to RXC delay (default set) */
@@ -77,6 +77,18 @@ static int bcm54612e_config_init(struct phy_device *phydev)
 				     MII_BCM54XX_AUXCTL_MISC_WREN | reg);
 	}
 
+	/* Enable CLK125 MUX on LED4 if ref clock is enabled. */
+	if (!(phydev->dev_flags & PHY_BRCM_RX_REFCLK_UNUSED)) {
+		int err;
+
+		reg = bcm_phy_read_exp(phydev, BCM54612E_EXP_SPARE0);
+		err = bcm_phy_write_exp(phydev, BCM54612E_EXP_SPARE0,
+					BCM54612E_LED4_CLK125OUT_EN | reg);
+
+		if (err < 0)
+			return err;
+	}
+
 	return 0;
 }
 
diff --git a/include/linux/brcmphy.h b/include/linux/brcmphy.h
index b324e01ccf2d..daa9234a9baf 100644
--- a/include/linux/brcmphy.h
+++ b/include/linux/brcmphy.h
@@ -85,6 +85,7 @@
 #define MII_BCM54XX_EXP_SEL	0x17	/* Expansion register select */
 #define MII_BCM54XX_EXP_SEL_SSD	0x0e00	/* Secondary SerDes select */
 #define MII_BCM54XX_EXP_SEL_ER	0x0f00	/* Expansion register select */
+#define MII_BCM54XX_EXP_SEL_ETC	0x0d00	/* Expansion register spare + 2k mem */
 
 #define MII_BCM54XX_AUX_CTL	0x18	/* Auxiliary control register */
 #define MII_BCM54XX_ISR		0x1a	/* BCM54xx interrupt status register */
@@ -219,6 +220,9 @@
 #define BCM54810_SHD_CLK_CTL			0x3
 #define BCM54810_SHD_CLK_CTL_GTXCLK_EN		(1 << 9)
 
+/* BCM54612E Registers */
+#define BCM54612E_EXP_SPARE0		(MII_BCM54XX_EXP_SEL_ETC + 0x34)
+#define BCM54612E_LED4_CLK125OUT_EN	(1 << 1)
 
 /*****************************************************************************/
 /* Fast Ethernet Transceiver definitions. */
-- 
2.17.1.1185.g55be947832-goog