[PATCH V3 net-next 2/4] net: phy: realtek: add dt property to disable CLKOUT clock

From: Joakim Zhang
Date: Mon Jun 07 2021 - 23:16:15 EST


CLKOUT is enabled by default after PHY hardware reset, this patch adds
"realtek,clkout-disable" property for user to disable CLKOUT clock
to save PHY power.

Per RTL8211F guide, a PHY reset should be issued after setting these
bits in PHYCR2 register. After this patch, CLKOUT clock output to be
disabled.

Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx>
---
drivers/net/phy/realtek.c | 42 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index 821e85a97367..ca258f2a9613 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -8,6 +8,7 @@
* Copyright (c) 2004 Freescale Semiconductor, Inc.
*/
#include <linux/bitops.h>
+#include <linux/of.h>
#include <linux/phy.h>
#include <linux/module.h>
#include <linux/delay.h>
@@ -27,6 +28,7 @@
#define RTL821x_PAGE_SELECT 0x1f

#define RTL8211F_PHYCR1 0x18
+#define RTL8211F_PHYCR2 0x19
#define RTL8211F_INSR 0x1d

#define RTL8211F_TX_DELAY BIT(8)
@@ -40,6 +42,8 @@
#define RTL8211E_TX_DELAY BIT(12)
#define RTL8211E_RX_DELAY BIT(11)

+#define RTL8211F_CLKOUT_EN BIT(0)
+
#define RTL8201F_ISR 0x1e
#define RTL8201F_ISR_ANERR BIT(15)
#define RTL8201F_ISR_DUPLEX BIT(13)
@@ -71,6 +75,10 @@ MODULE_DESCRIPTION("Realtek PHY driver");
MODULE_AUTHOR("Johnson Leung");
MODULE_LICENSE("GPL");

+struct rtl821x_priv {
+ u16 phycr2;
+};
+
static int rtl821x_read_page(struct phy_device *phydev)
{
return __phy_read(phydev, RTL821x_PAGE_SELECT);
@@ -81,6 +89,28 @@ static int rtl821x_write_page(struct phy_device *phydev, int page)
return __phy_write(phydev, RTL821x_PAGE_SELECT, page);
}

+static int rtl821x_probe(struct phy_device *phydev)
+{
+ struct device *dev = &phydev->mdio.dev;
+ struct rtl821x_priv *priv;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->phycr2 = phy_read_paged(phydev, 0xa43, RTL8211F_PHYCR2);
+ if (priv->phycr2 < 0)
+ return priv->phycr2;
+
+ priv->phycr2 &= RTL8211F_CLKOUT_EN;
+ if (of_property_read_bool(dev->of_node, "realtek,clkout-disable"))
+ priv->phycr2 &= ~RTL8211F_CLKOUT_EN;
+
+ phydev->priv = priv;
+
+ return 0;
+}
+
static int rtl8201_ack_interrupt(struct phy_device *phydev)
{
int err;
@@ -291,6 +321,7 @@ static int rtl8211c_config_init(struct phy_device *phydev)

static int rtl8211f_config_init(struct phy_device *phydev)
{
+ struct rtl821x_priv *priv = phydev->priv;
struct device *dev = &phydev->mdio.dev;
u16 val_txdly, val_rxdly;
u16 val;
@@ -354,7 +385,15 @@ static int rtl8211f_config_init(struct phy_device *phydev)
val_rxdly ? "enabled" : "disabled");
}

- return 0;
+ ret = phy_modify_paged(phydev, 0xa43, RTL8211F_PHYCR2,
+ RTL8211F_CLKOUT_EN, priv->phycr2);
+ if (ret < 0) {
+ dev_err(dev, "clkout configuration failed: %pe\n",
+ ERR_PTR(ret));
+ return ret;
+ }
+
+ return genphy_soft_reset(phydev);
}

static int rtl8211e_config_init(struct phy_device *phydev)
@@ -847,6 +886,7 @@ static struct phy_driver realtek_drvs[] = {
}, {
PHY_ID_MATCH_EXACT(0x001cc916),
.name = "RTL8211F Gigabit Ethernet",
+ .probe = rtl821x_probe,
.config_init = &rtl8211f_config_init,
.read_status = rtlgen_read_status,
.config_intr = &rtl8211f_config_intr,
--
2.17.1