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

From: Drew Fustini
Date: Thu Oct 03 2024 - 01:52:56 EST


On Tue, Oct 01, 2024 at 02:48:13AM -0700, Emil Renner Berthing wrote:
> 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()

Good point, I don't think there is any benefit to using regmap. I will
change the next revision to use writel() instead. I just tested this and
the network interface still works okay.

Thanks,
Drew

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
index f2f94539c0d2..df2fe0fdd128 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
@@ -13,7 +13,6 @@
#include <linux/of_device.h>
#include <linux/of_net.h>
#include <linux/platform_device.h>
-#include <linux/regmap.h>

#include "stmmac_platform.h"

@@ -52,15 +51,9 @@
#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;
+ void __iomem *apb_base;
struct device *dev;
};

@@ -85,7 +78,8 @@ static int thead_dwmac_set_phy_if(struct plat_stmmacenet_data *plat)
return -EINVAL;
};

- return regmap_write(dwmac->apb_regmap, GMAC_INTF_CTRL, phyif);
+ writel(phyif, dwmac->apb_base + GMAC_INTF_CTRL);
+ return 0;
}

static int thead_dwmac_set_txclk_dir(struct plat_stmmacenet_data *plat)
@@ -109,7 +103,8 @@ static int thead_dwmac_set_txclk_dir(struct plat_stmmacenet_data *plat)
return -EINVAL;
};

- return regmap_write(dwmac->apb_regmap, GMAC_TXCLK_OEN, txclk_dir);
+ writel(txclk_dir, dwmac->apb_base + GMAC_TXCLK_OEN);
+ return 0;
}

static void thead_dwmac_fix_speed(void *priv, unsigned int speed, unsigned int mode)
@@ -117,7 +112,7 @@ static void thead_dwmac_fix_speed(void *priv, unsigned int speed, unsigned int m
struct plat_stmmacenet_data *plat;
struct thead_dwmac *dwmac = priv;
unsigned long rate;
- u32 div;
+ u32 div, reg;

plat = dwmac->plat;

@@ -137,7 +132,7 @@ static void thead_dwmac_fix_speed(void *priv, unsigned int speed, unsigned int m
return;
}

- regmap_update_bits(dwmac->apb_regmap, GMAC_PLLCLK_DIV, GMAC_PLLCLK_DIV_EN, 0);
+ writel(FIELD_PREP(GMAC_PLLCLK_DIV_EN, 0), dwmac->apb_base + GMAC_PLLCLK_DIV);

switch (speed) {
case SPEED_1000:
@@ -153,11 +148,10 @@ static void thead_dwmac_fix_speed(void *priv, unsigned int speed, unsigned int m
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);
+ reg = FIELD_PREP(GMAC_PLLCLK_DIV_EN, 1) |
+ FIELD_PREP(GMAC_PLLCLK_DIV_MASK, GMAC_PLLCLK_DIV_NUM(div));
+ writel(reg, dwmac->apb_base + GMAC_PLLCLK_DIV);
break;
default:
dev_err(dwmac->dev, "unsupported phy interface %d\n",
@@ -169,7 +163,6 @@ static void thead_dwmac_fix_speed(void *priv, unsigned int speed, unsigned int m
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) {
@@ -182,11 +175,7 @@ static int thead_dwmac_enable_clk(struct plat_stmmacenet_data *plat)
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");
-
+ writel(GMAC_GTXCLK_SEL_PLL, dwmac->apb_base + GMAC_GTXCLK_SEL);
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;
@@ -197,7 +186,8 @@ static int thead_dwmac_enable_clk(struct plat_stmmacenet_data *plat)
return -EINVAL;
}

- return regmap_write(dwmac->apb_regmap, GMAC_CLK_EN, reg);
+ writel(reg, dwmac->apb_base + GMAC_CLK_EN);
+ return 0;
}

static int thead_dwmac_init(struct platform_device *pdev, void *priv)
@@ -213,17 +203,8 @@ static int thead_dwmac_init(struct platform_device *pdev, void *priv)
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");
+ writel(GMAC_RXCLK_DELAY_VAL(0), dwmac->apb_base + GMAC_RXCLK_DELAY_CTRL);
+ writel(GMAC_TXCLK_DELAY_VAL(0), dwmac->apb_base + GMAC_TXCLK_DELAY_CTRL);

return thead_dwmac_enable_clk(dwmac->plat);
}
@@ -255,13 +236,9 @@ static int thead_dwmac_probe(struct platform_device *pdev)
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");
-
dwmac->dev = &pdev->dev;
dwmac->plat = plat;
+ dwmac->apb_base = apb;
plat->bsp_priv = dwmac;
plat->fix_mac_speed = thead_dwmac_fix_speed;
plat->init = thead_dwmac_init;