Re: [PATCH v8 6/6] net: stmmac: starfive_dmac: Add phy interface settings

[Guo Samin <samin.guo@starfivetech.com>]

Re: [PATCH v8 6/6] net: stmmac: starfive_dmac: Add phy interface settings
From: Emil Renner Berthing <emil.renner.berthing@canonical.com>
to: Samin Guo <samin.guo@starfivetech.com>
data: 2023/3/24

> On Fri, 24 Mar 2023 at 03:30, Samin Guo <samin.guo@starfivetech.com> wrote:
>>
>> dwmac supports multiple modess. When working under rmii and rgmii,
>> you need to set different phy interfaces.
>>
>> According to the dwmac document, when working in rmii, it needs to be
>> set to 0x4, and rgmii needs to be set to 0x1.
>>
>> The phy interface needs to be set in syscon, the format is as follows:
>> starfive,syscon: <&syscon, offset, shift>
>>
>> Tested-by: Tommaso Merciai <tomm.merciai@gmail.com>
>> Signed-off-by: Samin Guo <samin.guo@starfivetech.com>
>> ---
>>  .../ethernet/stmicro/stmmac/dwmac-starfive.c  | 47 +++++++++++++++++++
>>  1 file changed, 47 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
>> index ef5a769b1c75..84690c8f0250 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-starfive.c
>> @@ -13,6 +13,10 @@
>>
>>  #include "stmmac_platform.h"
>>
>> +#define STARFIVE_DWMAC_PHY_INFT_RGMII  0x1
>> +#define STARFIVE_DWMAC_PHY_INFT_RMII   0x4
>> +#define STARFIVE_DWMAC_PHY_INFT_FIELD  0x7U
>> +
>>  struct starfive_dwmac {
>>         struct device *dev;
>>         struct clk *clk_tx;
>> @@ -44,6 +48,43 @@ static void starfive_dwmac_fix_mac_speed(void *priv, unsigned int speed)
>>                 dev_err(dwmac->dev, "failed to set tx rate %lu\n", rate);
>>  }
>>
>> +static int starfive_dwmac_set_mode(struct plat_stmmacenet_data *plat_dat)
>> +{
>> +       struct starfive_dwmac *dwmac = plat_dat->bsp_priv;
>> +       struct regmap *regmap;
>> +       unsigned int args[2];
>> +       unsigned int mode;
>> +
>> +       switch (plat_dat->interface) {
>> +       case PHY_INTERFACE_MODE_RMII:
>> +               mode = STARFIVE_DWMAC_PHY_INFT_RMII;
>> +               break;
>> +
>> +       case PHY_INTERFACE_MODE_RGMII:
>> +       case PHY_INTERFACE_MODE_RGMII_ID:
>> +               mode = STARFIVE_DWMAC_PHY_INFT_RGMII;
>> +               break;
>> +
>> +       default:
>> +               dev_err(dwmac->dev, "unsupported interface %d\n",
>> +                       plat_dat->interface);
>> +               return -EINVAL;
>> +       }
>> +
>> +       regmap = syscon_regmap_lookup_by_phandle_args(dwmac->dev->of_node,
>> +                                                     "starfive,syscon",
>> +                                                     2, args);
>> +       if (IS_ERR(regmap)) {
>> +               dev_err(dwmac->dev, "syscon regmap failed.\n");
>> +               return -ENXIO;
>> +       }
>> +
>> +       /* args[0]:offset  args[1]: shift */
>> +       return regmap_update_bits(regmap, args[0],
>> +                                 STARFIVE_DWMAC_PHY_INFT_FIELD << args[1],
>> +                                 mode << args[1]);
>> +}
>> +
>>  static int starfive_dwmac_probe(struct platform_device *pdev)
>>  {
>>         struct plat_stmmacenet_data *plat_dat;
>> @@ -89,6 +130,12 @@ static int starfive_dwmac_probe(struct platform_device *pdev)
>>         plat_dat->bsp_priv = dwmac;
>>         plat_dat->dma_cfg->dche = true;
>>
>> +       err = starfive_dwmac_set_mode(plat_dat);
>> +       if (err) {
>> +               dev_err(&pdev->dev, "dwmac set mode failed.\n");
>> +               return err;
>> +       }
> 
> Usually it's better to keep all error messages at the same "level".
> Like this you'll get two error messages if
> syscon_regmap_lookup_by_phandle_args fails. So I'd suggest moving this
> message into the starfive_dwmac_set_mode function and while you're at
> it you can do
> 
> err = regmap_update_bits(...);
> if (err)
>   return dev_err_probe(dwmac->dev, err, "error setting phy mode\n");
> 
> Also the file is called dwmac-starfive.c, so I'd expect the patch
> header to be "net: stmmac: dwmac-starfive: Add phy interface
> settings".
> 
> /Emil
> 

Thanks, the next version will be optimized.

Best regards,
Samin
>>         err = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
>>         if (err) {
>>                 stmmac_remove_config_dt(pdev, plat_dat);
>> --
>> 2.17.1
>>
>>
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