[PATCH v2 5/7] net: phy: realtek: Support SSC for the RTL8211E

Matthias Kaehlcke
2019-07-03T19:37:47Z

By default Spread-Spectrum Clocking (SSC) is disabled on the RTL8211E.
Enable it if the device tree property 'realtek,enable-ssc' exists.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
Changes in v2:
- enable SSC in config_init() instead of probe()
- fixed error check after enabling SSC
---
drivers/net/phy/realtek.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index 9cd6241e2a6d..45fee4612031 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -9,6 +9,7 @@
* Copyright (c) 2004 Freescale Semiconductor, Inc.
*/
#include <linux/bitops.h>
+#include <linux/device.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy.h>
@@ -34,6 +35,10 @@
#define RTL8211E_EEE_LED_MODE1 0x05
#define RTL8211E_EEE_LED_MODE2 0x06

+/* RTL8211E extension page 160 */
+#define RTL8211E_SCR 0x1a
+#define RTL8211E_SCR_DISABLE_RXC_SSC BIT(2)
+
#define RTL8211F_INSR 0x1d

#define RTL8211F_TX_DELAY BIT(8)
@@ -76,8 +81,8 @@ static int rtl8211e_select_ext_page(struct phy_device *phydev, int page)
return 0;
}

-static int __maybe_unused rtl8211e_modify_ext_paged(struct phy_device *phydev,
- int page, u32 regnum, u16 mask, u16 set)
+static int rtl8211e_modify_ext_paged(struct phy_device *phydev, int page,
+ u32 regnum, u16 mask, u16 set)
{
int ret = 0;
int oldpage;
@@ -122,6 +127,15 @@ static int rtl8211e_disable_eee_led_mode(struct phy_device *phydev)
static int rtl8211e_config_init(struct phy_device *phydev)
{
struct device *dev = &phydev->mdio.dev;
+ int ret;
+
+ if (of_property_read_bool(dev->of_node, "realtek,enable-ssc")) {
+ ret = rtl8211e_modify_ext_paged(phydev, 0xa0, RTL8211E_SCR,
+ RTL8211E_SCR_DISABLE_RXC_SSC,
+ 0);
+ if (ret < 0)
+ dev_err(dev, "failed to enable SSC on RXC: %d\n", ret);
+ }

if (of_property_read_bool(dev->of_node, "realtek,eee-led-mode-disable"))
rtl8211e_disable_eee_led_mode(phydev);
--
2.22.0.410.gd8fdbe21b5-goog