[PATCH 2/2] net: phy: realtek: Add optional external PHY clock

[Detlev Casanova <detlev.casanova@collabora.com>]

In some cases, the PHY can use an external clock source instead of a
crystal.

Add an optional clock in the phy node to make sure that the clock source
is enabled, if specified, before probing.

Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
---
 drivers/net/phy/realtek.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index 3d99fd6664d7..70c75dbbf799 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -12,6 +12,7 @@
 #include <linux/phy.h>
 #include <linux/module.h>
 #include <linux/delay.h>
+#include <linux/clk.h>
 
 #define RTL821x_PHYSR				0x11
 #define RTL821x_PHYSR_DUPLEX			BIT(13)
@@ -80,6 +81,7 @@ struct rtl821x_priv {
 	u16 phycr1;
 	u16 phycr2;
 	bool has_phycr2;
+	struct clk *clk;
 };
 
 static int rtl821x_read_page(struct phy_device *phydev)
@@ -103,6 +105,11 @@ static int rtl821x_probe(struct phy_device *phydev)
 	if (!priv)
 		return -ENOMEM;
 
+	priv->clk = devm_clk_get_optional_enabled(dev, "xtal");
+	if (IS_ERR(priv->clk))
+		return dev_err_probe(dev, PTR_ERR(priv->clk),
+				     "failed to get phy xtal clock\n");
+
 	ret = phy_read_paged(phydev, 0xa43, RTL8211F_PHYCR1);
 	if (ret < 0)
 		return ret;
-- 
2.39.3