[PATCH v3 2/7] net: phy: realtek: Allow disabling RTL8211E EEE LED mode

[Matthias Kaehlcke <mka@chromium.org>]

EEE LED mode is enabled by default on the RTL8211E. Disable it when
the device tree property 'realtek,eee-led-mode-disable' exists.

The magic values to disable EEE LED mode were taken from the RTL8211E
datasheet, unfortunately they are not further documented.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
TODO: DT validation

Changes in v3:
- don't have two versions of rtl8211e_config_init()
  (was due to my dev kernel being 4.19, which doesn't have
   this function yet)
- changed return type of rtl8211e_disable_eee_led_mode() to void
- added empty line after rtl8211e_config_init()

Changes in v2:
- patch added to the series
---
 drivers/net/phy/realtek.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index a669945eb829..827ea7ed080d 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -9,8 +9,9 @@
  * Copyright (c) 2004 Freescale Semiconductor, Inc.
  */
 #include <linux/bitops.h>
-#include <linux/phy.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy.h>
 
 #define RTL821x_PHYSR				0x11
 #define RTL821x_PHYSR_DUPLEX			BIT(13)
@@ -26,6 +27,10 @@
 #define RTL821x_EXT_PAGE_SELECT			0x1e
 #define RTL821x_PAGE_SELECT			0x1f
 
+/* RTL8211E page 5 */
+#define RTL8211E_EEE_LED_MODE1			0x05
+#define RTL8211E_EEE_LED_MODE2			0x06
+
 #define RTL8211F_INSR				0x1d
 
 #define RTL8211F_TX_DELAY			BIT(8)
@@ -53,6 +58,26 @@ static int rtl821x_write_page(struct phy_device *phydev, int page)
 	return __phy_write(phydev, RTL821x_PAGE_SELECT, page);
 }
 
+static void rtl8211e_disable_eee_led_mode(struct phy_device *phydev)
+{
+	int oldpage;
+	int err = 0;
+
+	oldpage = phy_select_page(phydev, 5);
+	if (oldpage < 0)
+		goto out;
+
+	/* write magic values to disable EEE LED mode */
+	err = __phy_write(phydev, RTL8211E_EEE_LED_MODE1, 0x8b82);
+	if (err)
+		goto out;
+
+	err = __phy_write(phydev, RTL8211E_EEE_LED_MODE2, 0x052b);
+
+out:
+	phy_restore_page(phydev, oldpage, err);
+}
+
 static int rtl8201_ack_interrupt(struct phy_device *phydev)
 {
 	int err;
@@ -184,9 +209,13 @@ static int rtl8211f_config_init(struct phy_device *phydev)
 
 static int rtl8211e_config_init(struct phy_device *phydev)
 {
+	struct device *dev = &phydev->mdio.dev;
 	int ret = 0, oldpage;
 	u16 val;
 
+	if (of_property_read_bool(dev->of_node, "realtek,eee-led-mode-disable"))
+		rtl8211e_disable_eee_led_mode(phydev);
+
 	/* enable TX/RX delay for rgmii-* modes, and disable them for rgmii. */
 	switch (phydev->interface) {
 	case PHY_INTERFACE_MODE_RGMII:
-- 
2.22.0.410.gd8fdbe21b5-goog