Re: [-net-next v11 5/6] net: stmmac: Add glue layer for StarFive JH7110 SoC
From: Guo Samin
Date: Fri Apr 07 2023 - 21:16:14 EST
Re: [-net-next v11 5/6] net: stmmac: Add glue layer for StarFive JH7110 SoC
From: Emil Renner Berthing <emil.renner.berthing@xxxxxxxxxxxxx>
to: Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
data: 2023/4/8
> On Fri, 7 Apr 2023 at 13:05, Samin Guo <samin.guo@xxxxxxxxxxxxxxxx> wrote:
>>
>> This adds StarFive dwmac driver support on the StarFive JH7110 SoC.
>>
>> Tested-by: Tommaso Merciai <tomm.merciai@xxxxxxxxx>
>> Co-developed-by: Emil Renner Berthing <kernel@xxxxxxxx>
>> Signed-off-by: Emil Renner Berthing <kernel@xxxxxxxx>
>> Signed-off-by: Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
>> ---
>> 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@xxxxxxxx>
>> M: Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
>> 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@xxxxxxxx>
>> 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@xxxxxxxx>
>> + * 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.
>
Hi Emil,
We used the solution you mentioned before V3, but Arun Ramadoss doesn't think that's great.
(https://patchwork.kernel.org/project/linux-riscv/patch/20230106030001.1952-6-yanhong.wang@xxxxxxxxxxxxxxxx)
> +static void starfive_eth_plat_fix_mac_speed(void *priv, unsigned int
> speed)
> +{
> + struct starfive_dwmac *dwmac = priv;
> + unsigned long rate;
> + int err;
> +
> + 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);
> + return;
Do we need to return value, since it is invalid speed. But the return
value of function is void.(Arun Ramadoss)
So in v9, after discussing with Jakub Kicinski, the clk_set_rate was used to initialize the rate.
(It is a reference to Intel's scheme: dwmac-intel-plat.c: kmb_eth_fix_mac_speed)
(https://patchwork.kernel.org/project/linux-riscv/patch/20230328062009.25454-6-samin.guo@xxxxxxxxxxxxxxxx)
Best regards,
Samin
>> + }
>> +
>> + 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@xxxxxxxx>");
>> +MODULE_AUTHOR("Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>");
>> --
>> 2.17.1
>>
>>
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--
Best regards,
Samin