Add initial support for ethernet controller of the Spacemit K3 SoC.
This ethernet controller is almost a standard Synopsys DesignWare
MAC (version 5.40a). This controller require a syscon device to
configure some basic features, like interface type and internal delay.

Change from v4:
- https://lore.kernel.org/netdev/20260130022705.1059214-1-inochiama@gmail.com
patch 1:
1 Apply Rob's tag.
2 Adjust clock description according to Russell's suggestion.
patch 3:
1. Add set_phy_intf_sel() and get_interfaces() hook, suggested by Russell.

Change from v3:
- https://lore.kernel.org/netdev/20260128072931.875041-1-inochiama@gmail.com
patch 1:
1. fix the uncorrect compatible string postion
patch 3:
1. add "CTRL_" prefix to all ctrl register definition
2. only use delay config 0 to calculate delay code.
3. fix typo in the comment

Change from v2:
- https://lore.kernel.org/netdev/20260121071315.940130-1-inochiama@gmail.com
patch 1:
1. remove not needed compatible for select
2. drop empty line in "spacemit,apmu" properties
3. add spacemit,apmu properties to required.
patch 3:
1. remove misused phy_fix_phy_mode_for_mac_delays.
2. use local tx clock instead of the clk_tx_i in the dwmac.

Change from v1:
- https://lore.kernel.org/netdev/20260120043609.910302-1-inochiama@gmail.com
patch 1:
1. remove phy clock
patch 3:
1. improve comment and include something special about Spacmit K3 dwmac
2. reorder the included file
3. fix wrong delay macro used in spacemit_dwmac_set_delay.
4. add check for maximum supported delay.
5. use DIV_ROUND_CLOSEST to calculate best delay configuration.
6. use assign for the ctrl register initial value.
7. fix input when calling of_property_read_u32().

Inochi Amaoto (3):
  dt-bindings: net: Add support for Spacemit K3 dwmac
  net: stmmac: platform: Add snps,dwmac-5.40a IP compatible string
  net: stmmac: Add glue layer for Spacemit K3 SoC

 .../devicetree/bindings/net/snps,dwmac.yaml   |   2 +
 .../bindings/net/spacemit,k3-dwmac.yaml       | 103 ++++++++
 drivers/net/ethernet/stmicro/stmmac/Kconfig   |  12 +
 drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
 .../ethernet/stmicro/stmmac/dwmac-spacemit.c  | 226 ++++++++++++++++++
 .../ethernet/stmicro/stmmac/stmmac_platform.c |   1 +
 6 files changed, 345 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/spacemit,k3-dwmac.yaml
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-spacemit.c

--
2.53.0

Quoting Inochi Amaoto (2026-02-27 08:57:14)
> Add initial support for ethernet controller of the Spacemit K3 SoC.
> This ethernet controller is almost a standard Synopsys DesignWare
> MAC (version 5.40a). This controller require a syscon device to
> configure some basic features, like interface type and internal delay.

I don't know how we can accept this when it can't be tested since it still
doesn't come with the device tree nodes. If you don't want it to be part of the
series, just share a tree where this code is working. There are plenty of free
public git hosting sites available.

/Emil

>
> Change from v4:
> - https://lore.kernel.org/netdev/20260130022705.1059214-1-inochiama@gmail.com
> patch 1:
> 1 Apply Rob's tag.
> 2 Adjust clock description according to Russell's suggestion.
> patch 3:
> 1. Add set_phy_intf_sel() and get_interfaces() hook, suggested by Russell.
>
> Change from v3:
> - https://lore.kernel.org/netdev/20260128072931.875041-1-inochiama@gmail.com
> patch 1:
> 1. fix the uncorrect compatible string postion
> patch 3:
> 1. add "CTRL_" prefix to all ctrl register definition
> 2. only use delay config 0 to calculate delay code.
> 3. fix typo in the comment
>
> Change from v2:
> - https://lore.kernel.org/netdev/20260121071315.940130-1-inochiama@gmail.com
> patch 1:
> 1. remove not needed compatible for select
> 2. drop empty line in "spacemit,apmu" properties
> 3. add spacemit,apmu properties to required.
> patch 3:
> 1. remove misused phy_fix_phy_mode_for_mac_delays.
> 2. use local tx clock instead of the clk_tx_i in the dwmac.
>
> Change from v1:
> - https://lore.kernel.org/netdev/20260120043609.910302-1-inochiama@gmail.com
> patch 1:
> 1. remove phy clock
> patch 3:
> 1. improve comment and include something special about Spacmit K3 dwmac
> 2. reorder the included file
> 3. fix wrong delay macro used in spacemit_dwmac_set_delay.
> 4. add check for maximum supported delay.
> 5. use DIV_ROUND_CLOSEST to calculate best delay configuration.
> 6. use assign for the ctrl register initial value.
> 7. fix input when calling of_property_read_u32().
>
> Inochi Amaoto (3):
>   dt-bindings: net: Add support for Spacemit K3 dwmac
>   net: stmmac: platform: Add snps,dwmac-5.40a IP compatible string
>   net: stmmac: Add glue layer for Spacemit K3 SoC
>
>  .../devicetree/bindings/net/snps,dwmac.yaml   |   2 +
>  .../bindings/net/spacemit,k3-dwmac.yaml       | 103 ++++++++
>  drivers/net/ethernet/stmicro/stmmac/Kconfig   |  12 +
>  drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
>  .../ethernet/stmicro/stmmac/dwmac-spacemit.c  | 226 ++++++++++++++++++
>  .../ethernet/stmicro/stmmac/stmmac_platform.c |   1 +
>  6 files changed, 345 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/net/spacemit,k3-dwmac.yaml
>  create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-spacemit.c
>
> --
> 2.53.0
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

On Mon, Mar 02, 2026 at 08:08:59AM -0500, Emil Renner Berthing wrote:
> Quoting Inochi Amaoto (2026-02-27 08:57:14)
> > Add initial support for ethernet controller of the Spacemit K3 SoC.
> > This ethernet controller is almost a standard Synopsys DesignWare
> > MAC (version 5.40a). This controller require a syscon device to
> > configure some basic features, like interface type and internal delay.
> 
> I don't know how we can accept this when it can't be tested since it still
> doesn't come with the device tree nodes. If you don't want it to be part of the
> series, just share a tree where this code is working. There are plenty of free
> public git hosting sites available.
> 

It seems like you have not read my reply before, I was forbidden from
opening other's patch. So some dependency can not be satisfied. For me,
the only thing I can open is the ethernet device node. The other things,
like clock, pinctrl and gpio devices. You should collect by yourself and
I can not provide.

Here is the ethernet DTS patch

diff --git a/arch/riscv/boot/dts/spacemit/k3-pico-itx.dts b/arch/riscv/boot/dts/spacemit/k3-pico-itx.dts
index b691304d4b74..1dfeef564ef3 100644
--- a/arch/riscv/boot/dts/spacemit/k3-pico-itx.dts
+++ b/arch/riscv/boot/dts/spacemit/k3-pico-itx.dts
@@ -5,6 +5,7 @@
  */
 
 #include "k3.dtsi"
+#include "k3-pinctrl.dtsi"
 
 / {
 	model = "SpacemiT K3 Pico-ITX";
@@ -24,6 +25,25 @@ memory@100000000 {
 	};
 };
 
+&eth0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&gmac0_cfg>;
+
+	phy-mode = "rgmii-id";
+	phy-handle = <&phy0>;
+	status = "okay";
+
+	mdio {
+		phy0: phy@1 {
+			compatible = "ethernet-phy-ieee802.3-c22";
+			reg = <1>;
+			reset-gpios = <&gpio 0 15 GPIO_ACTIVE_LOW>;
+			reset-assert-us = <10000>;
+			reset-deassert-us = <10000>;
+		};
+	};
+};
+
 &uart0 {
 	status = "okay";
 };
diff --git a/arch/riscv/boot/dts/spacemit/k3-pinctrl.dtsi b/arch/riscv/boot/dts/spacemit/k3-pinctrl.dtsi
new file mode 100644
index 000000000000..aa8e7cfd7efe
--- /dev/null
+++ b/arch/riscv/boot/dts/spacemit/k3-pinctrl.dtsi
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+
+#include <dt-bindings/gpio/gpio.h>
+
+#define K3_PADCONF(pin, func) (((pin) << 16) | (func))
+
+&pinctrl {
+	gmac0_cfg: gmac0-cfg {
+		/* Base pins: - Used by RMII directly */
+		gmac0_base_pins: gmac0-0-pins {
+			pinmux = <K3_PADCONF(0, 1)>,
+				 <K3_PADCONF(1, 1)>,
+				 <K3_PADCONF(2, 1)>,
+				 <K3_PADCONF(3, 1)>,
+				 <K3_PADCONF(6, 1)>,
+				 <K3_PADCONF(7, 1)>,
+				 <K3_PADCONF(11, 1)>,
+				 <K3_PADCONF(12, 1)>,
+				 <K3_PADCONF(13, 1)>;
+
+			bias-disable;
+			drive-strength = <25>;
+			power-source = <1800>;
+		};
+
+		/* RGMII extra pins: add on top of base pins */
+		gmac0_rgmii_add_pins: gmac0-1-pins {
+			pinmux = <K3_PADCONF(4, 1)>,
+				 <K3_PADCONF(5, 1)>,
+				 <K3_PADCONF(8, 1)>,
+				 <K3_PADCONF(9, 1)>,
+				 <K3_PADCONF(10, 1)>;
+
+			bias-disable;
+			drive-strength = <25>;
+			power-source = <1800>;
+		};
+
+		/* Optional int pins */
+		gmac0_int_pins: gmac0-3-pins {
+			pinmux = <K3_PADCONF(14, 1)>;
+
+			bias-disable;
+			drive-strength = <25>;
+			power-source = <1800>;
+		};
+
+		gmac0-6-pins {
+			pinmux = <K3_PADCONF(15, 0)>;
+
+			bias-disable;
+			drive-strength = <25>;
+			power-source = <1800>;
+		};
+	};
+};
diff --git a/arch/riscv/boot/dts/spacemit/k3.dtsi b/arch/riscv/boot/dts/spacemit/k3.dtsi
index 6cc31e94c13a..066006826e92 100644
--- a/arch/riscv/boot/dts/spacemit/k3.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k3.dtsi
@@ -5,6 +5,7 @@
  */
 
 #include <dt-bindings/clock/spacemit,k3-clocks.h>
+#include <dt-bindings/reset/spacemit,k3-resets.h>
 #include <dt-bindings/interrupt-controller/irq.h>
 
 /dts-v1/;
@@ -437,6 +438,112 @@ soc: soc {
 		dma-noncoherent;
 		ranges;
 
+		gmac_axi_setup: stmmac-axi-config {
+			snps,wr_osr_lmt = <0xf>;
+			snps,rd_osr_lmt = <0xf>;
+			/* max axi burst len is 256 */
+			snps,blen = <256 128 64 32 16 0 0>;
+		};
+
+		eth0: ethernet@cac80000 {
+			compatible = "spacemit,k3-dwmac", "snps,dwmac-5.40a";
+			reg = <0x0 0xcac80000 0x0 0x2000>;
+			clocks = <&syscon_apmu CLK_APMU_EMAC0_BUS>,
+				 <&syscon_apmu CLK_APMU_EMAC0_1588>,
+				 <&syscon_apmu CLK_APMU_EMAC0_RGMII_TX>;
+			clock-names = "stmmaceth", "ptp_ref", "tx";
+			interrupt-parent = <&saplic>;
+			interrupts = <131 IRQ_TYPE_LEVEL_HIGH>,
+				     <276 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "macirq", "eth_wake_irq";
+			resets = <&syscon_apmu RESET_APMU_EMAC0>;
+			reset-names = "stmmaceth";
+			rx-fifo-depth = <8192>;
+			tx-fifo-depth = <8192>;
+			snps,multicast-filter-bins = <64>;
+			snps,perfect-filter-entries = <32>;
+			snps,aal;
+			snps,tso;
+			snps,txpbl = <8>;
+			snps,rxpbl = <8>;
+			snps,force_sf_dma_mode;
+			snps,axi-config = <&gmac_axi_setup>;
+			spacemit,apmu = <&syscon_apmu 0x3e4 0x3e8>;
+			status = "disabled";
+
+			mdio {
+				compatible = "snps,dwmac-mdio";
+				#address-cells = <1>;
+				#size-cells = <0>;
+			};
+		};
+
+		eth1: ethernet@cac82000 {
+			compatible = "spacemit,k3-dwmac", "snps,dwmac-5.40a";
+			reg = <0x0 0xcac82000 0x0 0x2000>;
+			clocks = <&syscon_apmu CLK_APMU_EMAC1_BUS>,
+				 <&syscon_apmu CLK_APMU_EMAC1_1588>,
+				 <&syscon_apmu CLK_APMU_EMAC1_RGMII_TX>;
+			clock-names = "stmmaceth", "ptp_ref", "tx";
+			interrupt-parent = <&saplic>;
+			interrupts = <133 IRQ_TYPE_LEVEL_HIGH>,
+				     <277 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "macirq", "eth_wake_irq";
+			resets = <&syscon_apmu RESET_APMU_EMAC1>;
+			reset-names = "stmmaceth";
+			rx-fifo-depth = <8192>;
+			tx-fifo-depth = <8192>;
+			snps,multicast-filter-bins = <64>;
+			snps,perfect-filter-entries = <32>;
+			snps,aal;
+			snps,tso;
+			snps,txpbl = <8>;
+			snps,rxpbl = <8>;
+			snps,force_sf_dma_mode;
+			snps,axi-config = <&gmac_axi_setup>;
+			spacemit,apmu = <&syscon_apmu 0x3ec 0x3f0>;
+			status = "disabled";
+
+			mdio {
+				compatible = "snps,dwmac-mdio";
+				#address-cells = <1>;
+				#size-cells = <0>;
+			};
+		};
+
+		eth2: ethernet@cac8e000 {
+			compatible = "spacemit,k3-dwmac", "snps,dwmac-5.40a";
+			reg = <0x0 0xcac8e000 0x0 0x2000>;
+			clocks = <&syscon_apmu CLK_APMU_EMAC2_BUS>,
+				 <&syscon_apmu CLK_APMU_EMAC2_1588>,
+				 <&syscon_apmu CLK_APMU_EMAC2_RGMII_TX>;
+			clock-names = "stmmaceth", "ptp_ref", "tx";
+			interrupt-parent = <&saplic>;
+			interrupts = <130 IRQ_TYPE_LEVEL_HIGH>,
+				     <278 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "macirq", "eth_wake_irq";
+			resets = <&syscon_apmu RESET_APMU_EMAC2>;
+			reset-names = "stmmaceth";
+			rx-fifo-depth = <4096>;
+			tx-fifo-depth = <4096>;
+			snps,multicast-filter-bins = <64>;
+			snps,perfect-filter-entries = <32>;
+			snps,aal;
+			snps,tso;
+			snps,txpbl = <8>;
+			snps,rxpbl = <8>;
+			snps,force_sf_dma_mode;
+			snps,axi-config = <&gmac_axi_setup>;
+			spacemit,apmu = <&syscon_apmu 0x248 0x24c>;
+			status = "disabled";
+
+			mdio {
+				compatible = "snps,dwmac-mdio";
+				#address-cells = <1>;
+				#size-cells = <0>;
+			};
+		};
+
 		syscon_apbc: system-controller@d4015000 {
 			compatible = "spacemit,k3-syscon-apbc";
 			reg = <0x0 0xd4015000 0x0 0x1000>;
-- 
2.53.0

Inochi