[PATCH net-next v9 3/4] net: stmmac: Add glue layer for Spacemit K3 SoC
From: Inochi Amaoto <inochiama@gmail.com>
Date: 2026-03-12 01:23:31
Also in:
linux-devicetree, linux-riscv, lkml, netdev, spacemit
Subsystem:
networking drivers, spacemit dwmac glue layer, stmmac ethernet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Inochi Amaoto, Linus Torvalds
The ethernet controller on Spacemit K3 SoC is Synopsys DesignWare MAC (version 5.40a), with the following special points: 1. The rate of the tx clock line is auto changed when the mac speed rate is changed, and no need for changing the input tx clock. 2. This controller require a extra syscon device to configure the interface type, enable wake up interrupt and delay configuration if needed. Add Spacemit dwmac driver support on the Spacemit K3 SoC. Signed-off-by: Inochi Amaoto <inochiama@gmail.com> Reviewed-by: Russell King (Oracle) <redacted> --- drivers/net/ethernet/stmicro/stmmac/Kconfig | 12 + drivers/net/ethernet/stmicro/stmmac/Makefile | 1 + .../ethernet/stmicro/stmmac/dwmac-spacemit.c | 227 ++++++++++++++++++ 3 files changed, 240 insertions(+) create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-spacemit.c
diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 07088d03dbab..d3a6ab7383fc 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig@@ -216,6 +216,18 @@ config DWMAC_SOPHGO for the stmmac device driver. This driver is used for the ethernet controllers on various Sophgo SoCs. +config DWMAC_SPACEMIT + tristate "Spacemit dwmac support" + depends on OF && (ARCH_SPACEMIT || COMPILE_TEST) + select MFD_SYSCON + default m if ARCH_SPACEMIT + help + Support for ethernet controllers on Spacemit RISC-V SoCs + + This selects the Spacemit platform specific glue layer support + for the stmmac device driver. This driver is used for the + Spacemit K3 ethernet controllers. + config DWMAC_STARFIVE tristate "StarFive dwmac support" depends on OF && (ARCH_STARFIVE || COMPILE_TEST)
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index c9263987ef8d..945c5354eced 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile@@ -27,6 +27,7 @@ obj-$(CONFIG_DWMAC_RZN1) += dwmac-rzn1.o obj-$(CONFIG_DWMAC_S32) += dwmac-s32.o obj-$(CONFIG_DWMAC_SOCFPGA) += dwmac-altr-socfpga.o obj-$(CONFIG_DWMAC_SOPHGO) += dwmac-sophgo.o +obj-$(CONFIG_DWMAC_SPACEMIT) += dwmac-spacemit.o obj-$(CONFIG_DWMAC_STARFIVE) += dwmac-starfive.o obj-$(CONFIG_DWMAC_STI) += dwmac-sti.o obj-$(CONFIG_DWMAC_STM32) += dwmac-stm32.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-spacemit.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-spacemit.c
new file mode 100644
index 000000000000..c47f26385831
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-spacemit.c@@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Spacemit DWMAC platform driver + * + * Copyright (C) 2026 Inochi Amaoto <inochiama@gmail.com> + */ + +#include <linux/clk.h> +#include <linux/math.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/mfd/syscon.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/regmap.h> + +#include "stmmac_platform.h" + +/* ctrl register bits */ +#define CTRL_PHY_INTF_RGMII BIT(3) +#define CTRL_PHY_INTF_MII BIT(4) +#define CTRL_WAKE_IRQ_EN BIT(9) +#define CTRL_PHY_IRQ_EN BIT(12) + +/* dline register bits */ +#define RGMII_RX_DLINE_EN BIT(0) +#define RGMII_RX_DLINE_STEP GENMASK(5, 4) +#define RGMII_RX_DLINE_CODE GENMASK(15, 8) +#define RGMII_TX_DLINE_EN BIT(16) +#define RGMII_TX_DLINE_STEP GENMASK(21, 20) +#define RGMII_TX_DLINE_CODE GENMASK(31, 24) + +#define MAX_DLINE_DELAY_CODE 0xff +#define MAX_WORKED_DELAY 2800 +/* Note: the delay step value is at 0.1ps */ +#define K3_DELAY_STEP 367 + +struct spacmit_dwmac { + struct regmap *apmu; + unsigned int ctrl_offset; + unsigned int dline_offset; +}; + +static int spacemit_dwmac_set_delay(struct spacmit_dwmac *dwmac, + unsigned int tx_code, unsigned int rx_code) +{ + unsigned int mask, val; + + mask = RGMII_TX_DLINE_STEP | RGMII_TX_DLINE_CODE | RGMII_TX_DLINE_EN | + RGMII_RX_DLINE_STEP | RGMII_RX_DLINE_CODE | RGMII_RX_DLINE_EN; + + /* + * Since the delay step provided by config 0 is small enough, and + * it can cover the range of the valid delay, so there is no needed + * to use other step config. + */ + val = FIELD_PREP(RGMII_TX_DLINE_STEP, 0) | + FIELD_PREP(RGMII_TX_DLINE_CODE, tx_code) | RGMII_TX_DLINE_EN | + FIELD_PREP(RGMII_RX_DLINE_STEP, 0) | + FIELD_PREP(RGMII_RX_DLINE_CODE, rx_code) | RGMII_RX_DLINE_EN; + + return regmap_update_bits(dwmac->apmu, dwmac->dline_offset, + mask, val); +} + +static int spacemit_dwmac_detected_delay_value(unsigned int delay) +{ + if (delay == 0) + return 0; + + if (delay > MAX_WORKED_DELAY) + return -EINVAL; + + /* + * Note K3 require a specific factor for calculate + * the delay, in this scenario it is 0.9. So the + * formula is code * step / 10 * 0.9 + */ + return DIV_ROUND_CLOSEST(delay * 10 * 10, K3_DELAY_STEP * 9); +} + +static int spacemit_dwmac_fix_delay(struct spacmit_dwmac *dwmac, + unsigned int tx_delay, + unsigned int rx_delay) +{ + int rx_code; + int tx_code; + + rx_code = spacemit_dwmac_detected_delay_value(rx_delay); + if (rx_code < 0) + return rx_code; + + tx_code = spacemit_dwmac_detected_delay_value(tx_delay); + if (tx_code < 0) + return tx_code; + + return spacemit_dwmac_set_delay(dwmac, tx_code, rx_code); +} + +static int spacemit_dwmac_update_irq_config(struct spacmit_dwmac *dwmac, + struct stmmac_resources *stmmac_res) +{ + unsigned int val = stmmac_res->wol_irq >= 0 ? CTRL_WAKE_IRQ_EN : 0; + unsigned int mask = CTRL_WAKE_IRQ_EN; + + return regmap_update_bits(dwmac->apmu, dwmac->ctrl_offset, + mask, val); +} + +static void spacemit_get_interfaces(struct stmmac_priv *priv, void *bsp_priv, + unsigned long *interfaces) +{ + __set_bit(PHY_INTERFACE_MODE_MII, interfaces); + __set_bit(PHY_INTERFACE_MODE_RMII, interfaces); + phy_interface_set_rgmii(interfaces); +} + +static int spacemit_set_phy_intf_sel(void *bsp_priv, u8 phy_intf_sel) +{ + unsigned int mask = CTRL_PHY_INTF_MII | CTRL_PHY_INTF_RGMII; + struct spacmit_dwmac *dwmac = bsp_priv; + unsigned int val = 0; + + switch (phy_intf_sel) { + case PHY_INTF_SEL_GMII_MII: + val = CTRL_PHY_INTF_MII; + break; + + case PHY_INTF_SEL_RMII: + break; + + case PHY_INTF_SEL_RGMII: + val = CTRL_PHY_INTF_RGMII; + break; + + default: + return -EINVAL; + } + + return regmap_update_bits(dwmac->apmu, dwmac->ctrl_offset, + mask, val); +} + +static int spacemit_dwmac_probe(struct platform_device *pdev) +{ + struct plat_stmmacenet_data *plat_dat; + struct stmmac_resources stmmac_res; + struct device *dev = &pdev->dev; + struct spacmit_dwmac *dwmac; + unsigned int offset[2]; + struct regmap *apmu; + struct clk *clk_tx; + u32 rx_delay = 0; + u32 tx_delay = 0; + int ret; + + ret = stmmac_get_platform_resources(pdev, &stmmac_res); + if (ret) + return dev_err_probe(dev, ret, + "failed to get platform resources\n"); + + dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL); + if (!dwmac) + return -ENOMEM; + + plat_dat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac); + if (IS_ERR(plat_dat)) + return dev_err_probe(dev, PTR_ERR(plat_dat), + "failed to parse DT parameters\n"); + + clk_tx = devm_clk_get_enabled(&pdev->dev, "tx"); + if (IS_ERR(clk_tx)) + return dev_err_probe(&pdev->dev, PTR_ERR(clk_tx), + "failed to get tx clock\n"); + + apmu = syscon_regmap_lookup_by_phandle_args(pdev->dev.of_node, + "spacemit,apmu", 2, + offset); + if (IS_ERR(apmu)) + return dev_err_probe(dev, PTR_ERR(apmu), + "Failed to get apmu regmap\n"); + + dwmac->apmu = apmu; + dwmac->ctrl_offset = offset[0]; + dwmac->dline_offset = offset[1]; + + ret = spacemit_dwmac_update_irq_config(dwmac, &stmmac_res); + if (ret) + return dev_err_probe(dev, ret, "Failed to configure irq config\n"); + + of_property_read_u32(pdev->dev.of_node, "tx-internal-delay-ps", + &tx_delay); + of_property_read_u32(pdev->dev.of_node, "rx-internal-delay-ps", + &rx_delay); + + plat_dat->get_interfaces = spacemit_get_interfaces; + plat_dat->set_phy_intf_sel = spacemit_set_phy_intf_sel; + plat_dat->bsp_priv = dwmac; + + ret = spacemit_dwmac_fix_delay(dwmac, tx_delay, rx_delay); + if (ret) + return dev_err_probe(dev, ret, "Failed to configure delay\n"); + + return stmmac_dvr_probe(dev, plat_dat, &stmmac_res); +} + +static const struct of_device_id spacemit_dwmac_match[] = { + { .compatible = "spacemit,k3-dwmac" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, spacemit_dwmac_match); + +static struct platform_driver spacemit_dwmac_driver = { + .probe = spacemit_dwmac_probe, + .remove = stmmac_pltfr_remove, + .driver = { + .name = "spacemit-dwmac", + .pm = &stmmac_pltfr_pm_ops, + .of_match_table = spacemit_dwmac_match, + }, +}; +module_platform_driver(spacemit_dwmac_driver); + +MODULE_AUTHOR("Inochi Amaoto <inochiama@gmail.com>"); +MODULE_DESCRIPTION("Spacemit DWMAC platform driver"); +MODULE_LICENSE("GPL");
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2.53.0