Re: [PATCH v3 2/3] net: stmmac: Add glue layer for T-HEAD TH1520 SoC

From: Emil Renner Berthing
Date: Tue Oct 01 2024 - 05:48:41 EST

Drew Fustini wrote:
> From: Jisheng Zhang <jszhang@xxxxxxxxxx>
>
> Add dwmac glue driver to support the DesignWare-based GMAC controllers
> on the T-HEAD TH1520 SoC.
>
> Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
> [esmil: rename plat->interface -> plat->mac_interface,
> use devm_stmmac_probe_config_dt()]
> Signed-off-by: Emil Renner Berthing <emil.renner.berthing@xxxxxxxxxxxxx>
> [drew: convert from stmmac_dvr_probe() to devm_stmmac_pltfr_probe()]
> Signed-off-by: Drew Fustini <dfustini@xxxxxxxxxxxxxxx>
> ---
> MAINTAINERS | 1 +
> drivers/net/ethernet/stmicro/stmmac/Kconfig | 11 +
> drivers/net/ethernet/stmicro/stmmac/Makefile | 1 +
> drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c | 291 ++++++++++++++++++++++
> 4 files changed, 304 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 9e50107efb37..1d24863c01df 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -19946,6 +19946,7 @@ F: Documentation/devicetree/bindings/net/thead,th1520-gmac.yaml
> F: Documentation/devicetree/bindings/pinctrl/thead,th1520-pinctrl.yaml
> F: arch/riscv/boot/dts/thead/
> F: drivers/clk/thead/clk-th1520-ap.c
> +F: drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
> F: drivers/pinctrl/pinctrl-th1520.c
> F: include/dt-bindings/clock/thead,th1520-clk-ap.h
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> index 05cc07b8f48c..82030adaf16e 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
> +++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> @@ -228,6 +228,17 @@ config DWMAC_SUN8I
> stmmac device driver. This driver is used for H3/A83T/A64
> EMAC ethernet controller.
>
> +config DWMAC_THEAD
> + tristate "T-HEAD dwmac support"
> + depends on OF && (ARCH_THEAD || COMPILE_TEST)
> + select MFD_SYSCON
> + help
> + Support for ethernet controllers on T-HEAD RISC-V SoCs
> +
> + This selects the T-HEAD platform specific glue layer support for
> + the stmmac device driver. This driver is used for T-HEAD TH1520
> + ethernet controller.
> +
> config DWMAC_IMX8
> tristate "NXP IMX8 DWMAC support"
> default ARCH_MXC
> diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
> index c2f0e91f6bf8..d065634c6223 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/Makefile
> +++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
> @@ -28,6 +28,7 @@ obj-$(CONFIG_DWMAC_STI) += dwmac-sti.o
> obj-$(CONFIG_DWMAC_STM32) += dwmac-stm32.o
> obj-$(CONFIG_DWMAC_SUNXI) += dwmac-sunxi.o
> obj-$(CONFIG_DWMAC_SUN8I) += dwmac-sun8i.o
> +obj-$(CONFIG_DWMAC_THEAD) += dwmac-thead.o
> obj-$(CONFIG_DWMAC_DWC_QOS_ETH) += dwmac-dwc-qos-eth.o
> obj-$(CONFIG_DWMAC_INTEL_PLAT) += dwmac-intel-plat.o
> obj-$(CONFIG_DWMAC_LOONGSON1) += dwmac-loongson1.o
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
> new file mode 100644
> index 000000000000..f2f94539c0d2
> --- /dev/null
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
> @@ -0,0 +1,291 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * T-HEAD DWMAC platform driver
> + *
> + * Copyright (C) 2021 Alibaba Group Holding Limited.
> + * Copyright (C) 2023 Jisheng Zhang <jszhang@xxxxxxxxxx>
> + *
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_net.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#include "stmmac_platform.h"
> +
> +#define GMAC_CLK_EN 0x00
> +#define GMAC_TX_CLK_EN BIT(1)
> +#define GMAC_TX_CLK_N_EN BIT(2)
> +#define GMAC_TX_CLK_OUT_EN BIT(3)
> +#define GMAC_RX_CLK_EN BIT(4)
> +#define GMAC_RX_CLK_N_EN BIT(5)
> +#define GMAC_EPHY_REF_CLK_EN BIT(6)
> +#define GMAC_RXCLK_DELAY_CTRL 0x04
> +#define GMAC_RXCLK_BYPASS BIT(15)
> +#define GMAC_RXCLK_INVERT BIT(14)
> +#define GMAC_RXCLK_DELAY_MASK GENMASK(4, 0)
> +#define GMAC_RXCLK_DELAY_VAL(x) FIELD_PREP(GMAC_RXCLK_DELAY_MASK, (x))
> +#define GMAC_TXCLK_DELAY_CTRL 0x08
> +#define GMAC_TXCLK_BYPASS BIT(15)
> +#define GMAC_TXCLK_INVERT BIT(14)
> +#define GMAC_TXCLK_DELAY_MASK GENMASK(4, 0)
> +#define GMAC_TXCLK_DELAY_VAL(x) FIELD_PREP(GMAC_RXCLK_DELAY_MASK, (x))
> +#define GMAC_PLLCLK_DIV 0x0c
> +#define GMAC_PLLCLK_DIV_EN BIT(31)
> +#define GMAC_PLLCLK_DIV_MASK GENMASK(7, 0)
> +#define GMAC_PLLCLK_DIV_NUM(x) FIELD_PREP(GMAC_PLLCLK_DIV_MASK, (x))
> +#define GMAC_GTXCLK_SEL 0x18
> +#define GMAC_GTXCLK_SEL_PLL BIT(0)
> +#define GMAC_INTF_CTRL 0x1c
> +#define PHY_INTF_MASK BIT(0)
> +#define PHY_INTF_RGMII FIELD_PREP(PHY_INTF_MASK, 1)
> +#define PHY_INTF_MII_GMII FIELD_PREP(PHY_INTF_MASK, 0)
> +#define GMAC_TXCLK_OEN 0x20
> +#define TXCLK_DIR_MASK BIT(0)
> +#define TXCLK_DIR_OUTPUT FIELD_PREP(TXCLK_DIR_MASK, 0)
> +#define TXCLK_DIR_INPUT FIELD_PREP(TXCLK_DIR_MASK, 1)
> +
> +#define GMAC_GMII_RGMII_RATE 125000000
> +#define GMAC_MII_RATE 25000000
> +
> +static const struct regmap_config regmap_config = {
> + .reg_bits = 32,
> + .val_bits = 32,
> + .reg_stride = 4,
> +};
> +
> +struct thead_dwmac {
> + struct plat_stmmacenet_data *plat;
> + struct regmap *apb_regmap;
> + struct device *dev;
> +};
> +
> +static int thead_dwmac_set_phy_if(struct plat_stmmacenet_data *plat)
> +{
> + struct thead_dwmac *dwmac = plat->bsp_priv;
> + u32 phyif;
> +
> + switch (plat->mac_interface) {
> + case PHY_INTERFACE_MODE_MII:
> + phyif = PHY_INTF_MII_GMII;
> + break;
> + case PHY_INTERFACE_MODE_RGMII:
> + case PHY_INTERFACE_MODE_RGMII_ID:
> + case PHY_INTERFACE_MODE_RGMII_TXID:
> + case PHY_INTERFACE_MODE_RGMII_RXID:
> + phyif = PHY_INTF_RGMII;
> + break;
> + default:
> + dev_err(dwmac->dev, "unsupported phy interface %d\n",
> + plat->mac_interface);
> + return -EINVAL;
> + };
> +
> + return regmap_write(dwmac->apb_regmap, GMAC_INTF_CTRL, phyif);
> +}
> +
> +static int thead_dwmac_set_txclk_dir(struct plat_stmmacenet_data *plat)
> +{
> + struct thead_dwmac *dwmac = plat->bsp_priv;
> + u32 txclk_dir;
> +
> + switch (plat->mac_interface) {
> + case PHY_INTERFACE_MODE_MII:
> + txclk_dir = TXCLK_DIR_INPUT;
> + break;
> + case PHY_INTERFACE_MODE_RGMII:
> + case PHY_INTERFACE_MODE_RGMII_ID:
> + case PHY_INTERFACE_MODE_RGMII_TXID:
> + case PHY_INTERFACE_MODE_RGMII_RXID:
> + txclk_dir = TXCLK_DIR_OUTPUT;
> + break;
> + default:
> + dev_err(dwmac->dev, "unsupported phy interface %d\n",
> + plat->mac_interface);
> + return -EINVAL;
> + };
> +
> + return regmap_write(dwmac->apb_regmap, GMAC_TXCLK_OEN, txclk_dir);
> +}
> +
> +static void thead_dwmac_fix_speed(void *priv, unsigned int speed, unsigned int mode)
> +{
> + struct plat_stmmacenet_data *plat;
> + struct thead_dwmac *dwmac = priv;
> + unsigned long rate;
> + u32 div;
> +
> + plat = dwmac->plat;
> +
> + switch (plat->mac_interface) {
> + /* For MII, rxc/txc is provided by phy */
> + case PHY_INTERFACE_MODE_MII:
> + return;
> +
> + case PHY_INTERFACE_MODE_RGMII:
> + case PHY_INTERFACE_MODE_RGMII_ID:
> + case PHY_INTERFACE_MODE_RGMII_RXID:
> + case PHY_INTERFACE_MODE_RGMII_TXID:
> + rate = clk_get_rate(plat->stmmac_clk);
> + if (!rate || rate % GMAC_GMII_RGMII_RATE != 0 ||
> + rate % GMAC_MII_RATE != 0) {
> + dev_err(dwmac->dev, "invalid gmac rate %ld\n", rate);
> + return;
> + }
> +
> + regmap_update_bits(dwmac->apb_regmap, GMAC_PLLCLK_DIV, GMAC_PLLCLK_DIV_EN, 0);
> +
> + switch (speed) {
> + case SPEED_1000:
> + div = rate / GMAC_GMII_RGMII_RATE;
> + break;
> + case SPEED_100:
> + div = rate / GMAC_MII_RATE;
> + break;
> + case SPEED_10:
> + div = rate * 10 / GMAC_MII_RATE;
> + break;
> + default:
> + dev_err(dwmac->dev, "invalid speed %u\n", speed);
> + return;
> + }
> + regmap_update_bits(dwmac->apb_regmap, GMAC_PLLCLK_DIV,
> + GMAC_PLLCLK_DIV_MASK, GMAC_PLLCLK_DIV_NUM(div));
> +
> + regmap_update_bits(dwmac->apb_regmap, GMAC_PLLCLK_DIV,
> + GMAC_PLLCLK_DIV_EN, GMAC_PLLCLK_DIV_EN);
> + break;
> + default:
> + dev_err(dwmac->dev, "unsupported phy interface %d\n",
> + plat->mac_interface);
> + return;
> + }
> +}
> +
> +static int thead_dwmac_enable_clk(struct plat_stmmacenet_data *plat)
> +{
> + struct thead_dwmac *dwmac = plat->bsp_priv;
> + int err;
> + u32 reg;
> +
> + switch (plat->mac_interface) {
> + case PHY_INTERFACE_MODE_MII:
> + reg = GMAC_RX_CLK_EN | GMAC_TX_CLK_EN;
> + break;
> +
> + case PHY_INTERFACE_MODE_RGMII:
> + case PHY_INTERFACE_MODE_RGMII_ID:
> + case PHY_INTERFACE_MODE_RGMII_RXID:
> + case PHY_INTERFACE_MODE_RGMII_TXID:
> + /* use pll */
> + err = regmap_write(dwmac->apb_regmap, GMAC_GTXCLK_SEL, GMAC_GTXCLK_SEL_PLL);
> + if (err)
> + return dev_err_probe(dwmac->dev, err,
> + "failed to set phy interface\n");
> +
> + reg = GMAC_TX_CLK_EN | GMAC_TX_CLK_N_EN | GMAC_TX_CLK_OUT_EN |
> + GMAC_RX_CLK_EN | GMAC_RX_CLK_N_EN;
> + break;
> +
> + default:
> + dev_err(dwmac->dev, "unsupported phy interface %d\n",
> + plat->mac_interface);
> + return -EINVAL;
> + }
> +
> + return regmap_write(dwmac->apb_regmap, GMAC_CLK_EN, reg);
> +}
> +
> +static int thead_dwmac_init(struct platform_device *pdev, void *priv)
> +{
> + struct thead_dwmac *dwmac = priv;
> + int ret;
> +
> + ret = thead_dwmac_set_phy_if(dwmac->plat);
> + if (ret)
> + return ret;
> +
> + ret = thead_dwmac_set_txclk_dir(dwmac->plat);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(dwmac->apb_regmap, GMAC_RXCLK_DELAY_CTRL,
> + GMAC_RXCLK_DELAY_VAL(0));
> + if (ret)
> + return dev_err_probe(dwmac->dev, ret,
> + "failed to set GMAC RX clock delay\n");
> +
> + ret = regmap_write(dwmac->apb_regmap, GMAC_TXCLK_DELAY_CTRL,
> + GMAC_TXCLK_DELAY_VAL(0));
> + if (ret)
> + return dev_err_probe(dwmac->dev, ret,
> + "failed to set GMAC TX clock delay\n");
> +
> + return thead_dwmac_enable_clk(dwmac->plat);
> +}
> +
> +static int thead_dwmac_probe(struct platform_device *pdev)
> +{
> + struct stmmac_resources stmmac_res;
> + struct plat_stmmacenet_data *plat;
> + struct thead_dwmac *dwmac;
> + void __iomem *apb;
> + int ret;
> +
> + ret = stmmac_get_platform_resources(pdev, &stmmac_res);
> + if (ret)
> + return dev_err_probe(&pdev->dev, ret,
> + "failed to get resources\n");
> +
> + plat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
> + if (IS_ERR(plat))
> + return dev_err_probe(&pdev->dev, PTR_ERR(plat),
> + "dt configuration failed\n");
> +
> + dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
> + if (!dwmac)
> + return -ENOMEM;
> +
> + apb = devm_platform_ioremap_resource(pdev, 1);
> + if (IS_ERR(apb))
> + return dev_err_probe(&pdev->dev, PTR_ERR(apb),
> + "Failed to remap gmac apb registers\n");
> +
> + dwmac->apb_regmap = devm_regmap_init_mmio(&pdev->dev, apb, &regmap_config);
> + if (IS_ERR(dwmac->apb_regmap))
> + return dev_err_probe(&pdev->dev, PTR_ERR(dwmac->apb_regmap),
> + "Failed to access gmac apb registers\n");

Why do you need to convert the APB range to a regmap? As far as I can tell it's
just regular 32bit memory mapped registers, so should work fine with just
readl()/writel()

/Emil

> +
> + dwmac->dev = &pdev->dev;
> + dwmac->plat = plat;
> + plat->bsp_priv = dwmac;
> + plat->fix_mac_speed = thead_dwmac_fix_speed;
> + plat->init = thead_dwmac_init;
> +
> + return devm_stmmac_pltfr_probe(pdev, plat, &stmmac_res);
> +}
> +
> +static const struct of_device_id thead_dwmac_match[] = {
> + { .compatible = "thead,th1520-gmac" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, thead_dwmac_match);
> +
> +static struct platform_driver thead_dwmac_driver = {
> + .probe = thead_dwmac_probe,
> + .driver = {
> + .name = "thead-dwmac",
> + .pm = &stmmac_pltfr_pm_ops,
> + .of_match_table = thead_dwmac_match,
> + },
> +};
> +module_platform_driver(thead_dwmac_driver);
> +
> +MODULE_AUTHOR("Jisheng Zhang <jszhang@xxxxxxxxxx>");
> +MODULE_AUTHOR("Drew Fustini <drew@xxxxxxxx>");
> +MODULE_DESCRIPTION("T-HEAD DWMAC platform driver");
> +MODULE_LICENSE("GPL");
>
> --
> 2.34.1
>
>
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