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authorOleksij Rempel <o.rempel@pengutronix.de>2024-01-24 15:33:14 +0300
committerJakub Kicinski <kuba@kernel.org>2024-01-27 08:25:25 +0300
commit9e62bed6e105f2f522e360a024fc93c64c58a207 (patch)
tree50c21a15c42a2928feef6ee5eafb6a2ea15c5663 /drivers/net/dsa/microchip
parentd1b7d0d85d59bfe6f57b1604a922466e4f8ee734 (diff)
downloadlinux-9e62bed6e105f2f522e360a024fc93c64c58a207.tar.xz
net: dsa: microchip: implement PHY loopback configuration for KSZ8794 and KSZ8873
Correct the PHY loopback bit handling in the ksz8_w_phy_bmcr and ksz8_r_phy_bmcr functions for KSZ8794 and KSZ8873 variants in the ksz8795 driver. Previously, the code erroneously used Bit 7 of port register 0xD for both chip variants, which is actually for LED configuration. This update ensures the correct registers and bits are used for the PHY loopback feature: - For KSZ8794: Use 0xF / Bit 7. - For KSZ8873: Use 0xD / Bit 0. The lack of loopback support was seen on KSZ8873 system by using "ethtool -t lanX". After this patch, the ethtool selftest will work, but only if port is not part of a bridge. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com> Link: https://lore.kernel.org/r/20240124123314.734815-4-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/dsa/microchip')
-rw-r--r--drivers/net/dsa/microchip/ksz8795.c76
-rw-r--r--drivers/net/dsa/microchip/ksz8795_reg.h1
2 files changed, 70 insertions, 7 deletions
diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 51e0194453df..50351cef6ca5 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -633,6 +633,57 @@ static void ksz8_w_vlan_table(struct ksz_device *dev, u16 vid, u16 vlan)
}
/**
+ * ksz879x_get_loopback - KSZ879x specific function to get loopback
+ * configuration status for a specific port
+ * @dev: Pointer to the device structure
+ * @port: Port number to query
+ * @val: Pointer to store the result
+ *
+ * This function reads the SMI registers to determine whether loopback mode
+ * is enabled for a specific port.
+ *
+ * Return: 0 on success, error code on failure.
+ */
+static int ksz879x_get_loopback(struct ksz_device *dev, u16 port,
+ u16 *val)
+{
+ u8 stat3;
+ int ret;
+
+ ret = ksz_pread8(dev, port, REG_PORT_STATUS_3, &stat3);
+ if (ret)
+ return ret;
+
+ if (stat3 & PORT_PHY_LOOPBACK)
+ *val |= BMCR_LOOPBACK;
+
+ return 0;
+}
+
+/**
+ * ksz879x_set_loopback - KSZ879x specific function to set loopback mode for
+ * a specific port
+ * @dev: Pointer to the device structure.
+ * @port: Port number to modify.
+ * @val: Value indicating whether to enable or disable loopback mode.
+ *
+ * This function translates loopback bit of the BMCR register into the
+ * corresponding hardware register bit value and writes it to the SMI interface.
+ *
+ * Return: 0 on success, error code on failure.
+ */
+static int ksz879x_set_loopback(struct ksz_device *dev, u16 port, u16 val)
+{
+ u8 stat3 = 0;
+
+ if (val & BMCR_LOOPBACK)
+ stat3 |= PORT_PHY_LOOPBACK;
+
+ return ksz_prmw8(dev, port, REG_PORT_STATUS_3, PORT_PHY_LOOPBACK,
+ stat3);
+}
+
+/**
* ksz8_r_phy_ctrl - Translates and reads from the SMI interface to a MIIM PHY
* Control register (Reg. 31).
* @dev: The KSZ device instance.
@@ -731,16 +782,20 @@ static int ksz8_r_phy_bmcr(struct ksz_device *dev, u16 port, u16 *val)
if (ret)
return ret;
- if (restart & PORT_PHY_LOOPBACK)
- *val |= BMCR_LOOPBACK;
-
if (ctrl & PORT_FORCE_100_MBIT)
*val |= BMCR_SPEED100;
if (ksz_is_ksz88x3(dev)) {
+ if (restart & KSZ8873_PORT_PHY_LOOPBACK)
+ *val |= BMCR_LOOPBACK;
+
if ((ctrl & PORT_AUTO_NEG_ENABLE))
*val |= BMCR_ANENABLE;
} else {
+ ret = ksz879x_get_loopback(dev, port, val);
+ if (ret)
+ return ret;
+
if (!(ctrl & PORT_AUTO_NEG_DISABLE))
*val |= BMCR_ANENABLE;
}
@@ -1001,8 +1056,7 @@ static int ksz8_w_phy_bmcr(struct ksz_device *dev, u16 port, u16 val)
restart = 0;
restart_mask = PORT_LED_OFF | PORT_TX_DISABLE | PORT_AUTO_NEG_RESTART |
- PORT_POWER_DOWN | PORT_AUTO_MDIX_DISABLE | PORT_FORCE_MDIX |
- PORT_PHY_LOOPBACK;
+ PORT_POWER_DOWN | PORT_AUTO_MDIX_DISABLE | PORT_FORCE_MDIX;
if (val & KSZ886X_BMCR_DISABLE_LED)
restart |= PORT_LED_OFF;
@@ -1022,8 +1076,16 @@ static int ksz8_w_phy_bmcr(struct ksz_device *dev, u16 port, u16 val)
if (val & KSZ886X_BMCR_FORCE_MDI)
restart |= PORT_FORCE_MDIX;
- if (val & BMCR_LOOPBACK)
- restart |= PORT_PHY_LOOPBACK;
+ if (ksz_is_ksz88x3(dev)) {
+ restart_mask |= KSZ8873_PORT_PHY_LOOPBACK;
+
+ if (val & BMCR_LOOPBACK)
+ restart |= KSZ8873_PORT_PHY_LOOPBACK;
+ } else {
+ ret = ksz879x_set_loopback(dev, port, val);
+ if (ret)
+ return ret;
+ }
return ksz_prmw8(dev, port, regs[P_NEG_RESTART_CTRL], restart_mask,
restart);
diff --git a/drivers/net/dsa/microchip/ksz8795_reg.h b/drivers/net/dsa/microchip/ksz8795_reg.h
index beca974e0171..7c9341ef73b0 100644
--- a/drivers/net/dsa/microchip/ksz8795_reg.h
+++ b/drivers/net/dsa/microchip/ksz8795_reg.h
@@ -265,6 +265,7 @@
#define PORT_AUTO_MDIX_DISABLE BIT(2)
#define PORT_FORCE_MDIX BIT(1)
#define PORT_MAC_LOOPBACK BIT(0)
+#define KSZ8873_PORT_PHY_LOOPBACK BIT(0)
#define REG_PORT_1_STATUS_2 0x1E
#define REG_PORT_2_STATUS_2 0x2E