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References: <20230407110356.8449-1-samin.guo@starfivetech.com> <20230407110356.8449-6-samin.guo@starfivetech.com>
In-Reply-To: <20230407110356.8449-6-samin.guo@starfivetech.com>
From:   Emil Renner Berthing <emil.renner.berthing@canonical.com>
Date:   Fri, 7 Apr 2023 21:11:39 +0200
Message-ID: <CAJM55Z9jCdPASsk+fw_j+9QH3+Kj28tpCA4PgW_nB_ce7qWL8w@mail.gmail.com>
Subject: Re: [-net-next v11 5/6] net: stmmac: Add glue layer for StarFive
 JH7110 SoC
To:     Samin Guo <samin.guo@starfivetech.com>
Cc:     linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
        devicetree@vger.kernel.org, netdev@vger.kernel.org,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Emil Renner Berthing <kernel@esmil.dk>,
        Pedro Moreira <pmmoreir@synopsys.com>,
        Richard Cochran <richardcochran@gmail.com>,
        Conor Dooley <conor@kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Andrew Lunn <andrew@lunn.ch>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Peter Geis <pgwipeout@gmail.com>,
        Yanhong Wang <yanhong.wang@starfivetech.com>,
        Tommaso Merciai <tomm.merciai@gmail.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Fri, 7 Apr 2023 at 13:05, Samin Guo <samin.guo@starfivetech.com> wrote:
>
> This adds StarFive dwmac driver support on the StarFive JH7110 SoC.
>
> Tested-by: Tommaso Merciai <tomm.merciai@gmail.com>
> Co-developed-by: Emil Renner Berthing <kernel@esmil.dk>
> Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
> Signed-off-by: Samin Guo <samin.guo@starfivetech.com>
> ---
>  MAINTAINERS                                   |   1 +
>  drivers/net/ethernet/stmicro/stmmac/Kconfig   |  12 ++
>  drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
>  .../ethernet/stmicro/stmmac/dwmac-starfive.c  | 123 ++++++++++++++++++
>  4 files changed, 137 insertions(+)
>  create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 6b6b67468b8f..46b366456cee 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -19910,6 +19910,7 @@ M:      Emil Renner Berthing <kernel@esmil.dk>
>  M:     Samin Guo <samin.guo@starfivetech.com>
>  S:     Maintained
>  F:     Documentation/devicetree/bindings/net/starfive,jh7110-dwmac.yaml
> +F:     drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
>
>  STARFIVE JH7100 CLOCK DRIVERS
>  M:     Emil Renner Berthing <kernel@esmil.dk>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> index f77511fe4e87..5f5a997f21f3 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
> +++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> @@ -165,6 +165,18 @@ config DWMAC_SOCFPGA
>           for the stmmac device driver. This driver is used for
>           arria5 and cyclone5 FPGA SoCs.
>
> +config DWMAC_STARFIVE
> +       tristate "StarFive dwmac support"
> +       depends on OF && (ARCH_STARFIVE || COMPILE_TEST)
> +       select MFD_SYSCON
> +       default m if ARCH_STARFIVE
> +       help
> +         Support for ethernet controllers on StarFive RISC-V SoCs
> +
> +         This selects the StarFive platform specific glue layer support for
> +         the stmmac device driver. This driver is used for StarFive JH7110
> +         ethernet controller.
> +
>  config DWMAC_STI
>         tristate "STi GMAC support"
>         default ARCH_STI
> diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
> index 057e4bab5c08..8738fdbb4b2d 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/Makefile
> +++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
> @@ -23,6 +23,7 @@ obj-$(CONFIG_DWMAC_OXNAS)     += dwmac-oxnas.o
>  obj-$(CONFIG_DWMAC_QCOM_ETHQOS)        += dwmac-qcom-ethqos.o
>  obj-$(CONFIG_DWMAC_ROCKCHIP)   += dwmac-rk.o
>  obj-$(CONFIG_DWMAC_SOCFPGA)    += dwmac-altr-socfpga.o
> +obj-$(CONFIG_DWMAC_STARFIVE)   += dwmac-starfive.o
>  obj-$(CONFIG_DWMAC_STI)                += dwmac-sti.o
>  obj-$(CONFIG_DWMAC_STM32)      += dwmac-stm32.o
>  obj-$(CONFIG_DWMAC_SUNXI)      += dwmac-sunxi.o
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
> new file mode 100644
> index 000000000000..4963d4008485
> --- /dev/null
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
> @@ -0,0 +1,123 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * StarFive DWMAC platform driver
> + *
> + * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk>
> + * Copyright (C) 2022 StarFive Technology Co., Ltd.
> + *
> + */
> +
> +#include <linux/mfd/syscon.h>
> +#include <linux/of_device.h>
> +#include <linux/regmap.h>
> +
> +#include "stmmac_platform.h"
> +
> +struct starfive_dwmac {
> +       struct device *dev;
> +       struct clk *clk_tx;
> +};
> +
> +static void starfive_dwmac_fix_mac_speed(void *priv, unsigned int speed)
> +{
> +       struct starfive_dwmac *dwmac = priv;
> +       unsigned long rate;
> +       int err;
> +
> +       rate = clk_get_rate(dwmac->clk_tx);

Hi Samin,

I'm not sure why you added this line in this revision. If it's just to
not call clk_set_rate on the uninitialized rate, I'd much rather you
just returned early and don't call clk_set_rate at all in case of
errors.

> +
> +       switch (speed) {
> +       case SPEED_1000:
> +               rate = 125000000;
> +               break;
> +       case SPEED_100:
> +               rate = 25000000;
> +               break;
> +       case SPEED_10:
> +               rate = 2500000;
> +               break;
> +       default:
> +               dev_err(dwmac->dev, "invalid speed %u\n", speed);
> +               break;

That is skip the clk_get_rate above and just change this break to a return.

> +       }
> +
> +       err = clk_set_rate(dwmac->clk_tx, rate);
> +       if (err)
> +               dev_err(dwmac->dev, "failed to set tx rate %lu\n", rate);
> +}
> +
> +static int starfive_dwmac_probe(struct platform_device *pdev)
> +{
> +       struct plat_stmmacenet_data *plat_dat;
> +       struct stmmac_resources stmmac_res;
> +       struct starfive_dwmac *dwmac;
> +       struct clk *clk_gtx;
> +       int err;
> +
> +       err = stmmac_get_platform_resources(pdev, &stmmac_res);
> +       if (err)
> +               return dev_err_probe(&pdev->dev, err,
> +                                    "failed to get resources\n");
> +
> +       plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
> +       if (IS_ERR(plat_dat))
> +               return dev_err_probe(&pdev->dev, PTR_ERR(plat_dat),
> +                                    "dt configuration failed\n");
> +
> +       dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
> +       if (!dwmac)
> +               return -ENOMEM;
> +
> +       dwmac->clk_tx = devm_clk_get_enabled(&pdev->dev, "tx");
> +       if (IS_ERR(dwmac->clk_tx))
> +               return dev_err_probe(&pdev->dev, PTR_ERR(dwmac->clk_tx),
> +                                    "error getting tx clock\n");
> +
> +       clk_gtx = devm_clk_get_enabled(&pdev->dev, "gtx");
> +       if (IS_ERR(clk_gtx))
> +               return dev_err_probe(&pdev->dev, PTR_ERR(clk_gtx),
> +                                    "error getting gtx clock\n");
> +
> +       /* Generally, the rgmii_tx clock is provided by the internal clock,
> +        * which needs to match the corresponding clock frequency according
> +        * to different speeds. If the rgmii_tx clock is provided by the
> +        * external rgmii_rxin, there is no need to configure the clock
> +        * internally, because rgmii_rxin will be adaptively adjusted.
> +        */
> +       if (!device_property_read_bool(&pdev->dev, "starfive,tx-use-rgmii-clk"))
> +               plat_dat->fix_mac_speed = starfive_dwmac_fix_mac_speed;
> +
> +       dwmac->dev = &pdev->dev;
> +       plat_dat->bsp_priv = dwmac;
> +       plat_dat->dma_cfg->dche = true;
> +
> +       err = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
> +       if (err) {
> +               stmmac_remove_config_dt(pdev, plat_dat);
> +               return err;
> +       }
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id starfive_dwmac_match[] = {
> +       { .compatible = "starfive,jh7110-dwmac" },
> +       { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, starfive_dwmac_match);
> +
> +static struct platform_driver starfive_dwmac_driver = {
> +       .probe  = starfive_dwmac_probe,
> +       .remove = stmmac_pltfr_remove,
> +       .driver = {
> +               .name = "starfive-dwmac",
> +               .pm = &stmmac_pltfr_pm_ops,
> +               .of_match_table = starfive_dwmac_match,
> +       },
> +};
> +module_platform_driver(starfive_dwmac_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("StarFive DWMAC platform driver");
> +MODULE_AUTHOR("Emil Renner Berthing <kernel@esmil.dk>");
> +MODULE_AUTHOR("Samin Guo <samin.guo@starfivetech.com>");
> --
> 2.17.1
>
>
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