ath79: force SGMII SerDes mode to MAC operation

The mode on the SGMII SerDes on the QCA9563 is 1000 Base-X by default.
This only allows for 1000 Mbit/s links, however when used with an SGMII
PHY in 100 Mbit/s link mode, the link remains dead.

This strictly has nothing to do with the SerDes calibration, however it
is done at the same point in the QCA reference U-Boot which is the
blueprint for everything happening here. As the current state is more or
less a hack, this should be fine.

This fixes the issues outlined above on a TP-Link EAP-225 Outdoor.

Reported-by: Tom Herbers <freifunk@tomherbers.de>
Tested-by: Tom Herbers <freifunk@tomherbers.de>
Signed-off-by: David Bauer <mail@david-bauer.net>
(cherry picked from commit fbbad9a9a629b388626b477e6cd692c160f63fb3)

diff --git a/target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c b/target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
index 07d9992ca7c91a8a6ebeb957284ebb94c89183cb..84b0f9e4ac87e1443d2c2b7ecf038ee90ebe29de 100644 (file)
--- a/target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
+++ b/target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
@@ -602,6 +602,11 @@ static void ag71xx_sgmii_serdes_init_qca956x(struct device_node *np)
                goto err_iomap;
        }
 
+       t = __raw_readl(gmac_base + QCA956X_GMAC_REG_SGMII_CONFIG);
+       t &= ~(QCA956X_SGMII_CONFIG_MODE_CTRL_MASK << QCA956X_SGMII_CONFIG_MODE_CTRL_SHIFT);
+       t |= QCA956X_SGMII_CONFIG_MODE_CTRL_SGMII_MAC;
+       __raw_writel(t, gmac_base + QCA956X_GMAC_REG_SGMII_CONFIG);
+
        pr_debug("%pOF: fixup SERDES calibration to value %i\n",
                np_dev, serdes_cal);
        t = __raw_readl(gmac_base + QCA956X_GMAC_REG_SGMII_SERDES);

diff --git a/target/linux/ath79/patches-5.4/0040-ath79-sgmii-config.patch b/target/linux/ath79/patches-5.4/0040-ath79-sgmii-config.patch
new file mode 100644 (file)
index 0000000..bf7cbf2
--- /dev/null
+++ b/target/linux/ath79/patches-5.4/0040-ath79-sgmii-config.patch
@@ -0,0 +1,9 @@
+--- a/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
++++ b/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
+@@ -1376,5 +1376,6 @@
+ 
+ #define QCA956X_SGMII_CONFIG_MODE_CTRL_SHIFT  0
+ #define QCA956X_SGMII_CONFIG_MODE_CTRL_MASK   0x7
++#define QCA956X_SGMII_CONFIG_MODE_CTRL_SGMII_MAC      0x2
+ 
+ #endif /* __ASM_MACH_AR71XX_REGS_H */