Thanks very much, with that and the patch from @musashino everything seems to work now, even the SFP slots!
For reference, this is my current device tree file, the two SFP slots are directly attached to the main chip on pins 94-97 and 99-102, as described in Section 6.5.5 of the datasheet, so I presume that phy-mode = "1000base-x"; is correct. It works in any case. The I2C connections I traced out are identical to those recently posted for the DGS-1210-10P H/W:R1, which is encouraging. I couldn't find a connection to the TX-fault pin of the SFP slots to any of the pins of the RTL8231.
rtl8382_d-link_dgs-1210-26.dts:
// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
#include "rtl8382_d-link_dgs-1210.dtsi"
/ {
compatible = "d-link,dgs-1210-26", "realtek,rtl838x-soc";
model = "D-Link DGS-1210-26";
/* Left SFP slot, port 25 */
i2c0: i2c-gpio-0 {
compatible = "i2c-gpio";
sda-gpios = <&gpio1 6 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
scl-gpios = <&gpio1 7 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
i2c-gpio,delay-us = <2>;
#address-cells = <1>;
#size-cells = <0>;
};
sfp0: sfp-p25 {
compatible = "sff,sfp";
i2c-bus = <&i2c0>;
los-gpio = <&gpio1 9 GPIO_ACTIVE_HIGH>;
mod-def0-gpio = <&gpio1 8 GPIO_ACTIVE_LOW>;
tx-disable-gpio = <&gpio1 11 GPIO_ACTIVE_HIGH>;
};
/* Right SFP slot, port 26 */
i2c1: i2c-gpio-1 {
compatible = "i2c-gpio";
sda-gpios = <&gpio1 1 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
scl-gpios = <&gpio1 2 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
i2c-gpio,delay-us = <2>;
#address-cells = <1>;
#size-cells = <0>;
};
sfp1: sfp-p26 {
compatible = "sff,sfp";
i2c-bus = <&i2c1>;
los-gpio = <&gpio1 4 GPIO_ACTIVE_HIGH>;
mod-def0-gpio = <&gpio1 3 GPIO_ACTIVE_LOW>;
tx-disable-gpio = <&gpio1 12 GPIO_ACTIVE_HIGH>;
};
};
&gpio1 {
status = "okay";
};
ðernet0 {
mdio: mdio-bus {
compatible = "realtek,rtl838x-mdio";
regmap = <ðernet0>;
#address-cells = <1>;
#size-cells = <0>;
EXTERNAL_PHY(0)
EXTERNAL_PHY(1)
EXTERNAL_PHY(2)
EXTERNAL_PHY(3)
EXTERNAL_PHY(4)
EXTERNAL_PHY(5)
EXTERNAL_PHY(6)
EXTERNAL_PHY(7)
INTERNAL_PHY(8)
INTERNAL_PHY(9)
INTERNAL_PHY(10)
INTERNAL_PHY(11)
INTERNAL_PHY(12)
INTERNAL_PHY(13)
INTERNAL_PHY(14)
INTERNAL_PHY(15)
EXTERNAL_PHY(16)
EXTERNAL_PHY(17)
EXTERNAL_PHY(18)
EXTERNAL_PHY(19)
EXTERNAL_PHY(20)
EXTERNAL_PHY(21)
EXTERNAL_PHY(22)
EXTERNAL_PHY(23)
INTERNAL_PHY(24)
INTERNAL_PHY(26)
};
};
&switch0 {
ports {
#address-cells = <1>;
#size-cells = <0>;
SWITCH_PORT(0, 1, qsgmii)
SWITCH_PORT(1, 2, qsgmii)
SWITCH_PORT(2, 3, qsgmii)
SWITCH_PORT(3, 4, qsgmii)
SWITCH_PORT(4, 5, qsgmii)
SWITCH_PORT(5, 6, qsgmii)
SWITCH_PORT(6, 7, qsgmii)
SWITCH_PORT(7, 8, qsgmii)
SWITCH_PORT(8, 9, internal)
SWITCH_PORT(9, 10, internal)
SWITCH_PORT(10, 11, internal)
SWITCH_PORT(11, 12, internal)
SWITCH_PORT(12, 13, internal)
SWITCH_PORT(13, 14, internal)
SWITCH_PORT(14, 15, internal)
SWITCH_PORT(15, 16, internal)
SWITCH_PORT(16, 17, qsgmii)
SWITCH_PORT(17, 18, qsgmii)
SWITCH_PORT(18, 19, qsgmii)
SWITCH_PORT(19, 20, qsgmii)
SWITCH_PORT(20, 21, qsgmii)
SWITCH_PORT(21, 22, qsgmii)
SWITCH_PORT(22, 23, qsgmii)
SWITCH_PORT(23, 24, qsgmii)
port@24 {
reg = <24>;
label = "lan25";
phy-mode = "1000base-x";
managed = "in-band-status";
sfp = <&sfp0>;
};
port@26 {
reg = <26>;
label = "lan26";
phy-mode = "1000base-x";
managed = "in-band-status";
sfp = <&sfp1>;
};
port@28 {
ethernet = <ðernet0>;
reg = <28>;
phy-mode = "internal";
fixed-link {
speed = <1000>;
full-duplex;
};
};
};
};
I believe this model might be able to use all 24 copper ports as well as the 2 SFP slots at the same time (as per the diagram in section 3.4 of the datasheet) - but I have not tried this yet.