[PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

Paul Menzel pmenzel at molgen.mpg.de
Tue Jan 14 13:21:59 AEDT 2025


Dear Andrew,


Thank you for your quick reply.


Am 14.01.25 um 21:16 schrieb Andrew Lunn:
>>> +#define NVT_MISCR_RMII          BIT(0)
>>> +
>>> +/* 2000ps is mapped to 0x0 ~ 0xF */
>>
>> Excuse my ignorance: What is ps?
> 
> picoseconds. An RGMII link needs a 2ns delay between the clock line
> and the data lines. Some MACs allow you to tune the delay they can
> insert, in this case in steps of 2ns / 16.

Thank you for the clarification. Maybe it’s my English, but I didn’t 
deduce this from how the comment is worded. I do not have a better idea 
either.

>>> +#define NVT_PATH_DELAY_DEC      134
>>> +#define NVT_TX_DELAY_MASK       GENMASK(19, 16)
>>> +#define NVT_RX_DELAY_MASK       GENMASK(23, 20)
>>> +
>>> +struct nvt_priv_data {
>>> +	struct platform_device *pdev;
>>> +	struct regmap *regmap;
>>> +};
>>> +
>>> +static struct nvt_priv_data *
>>> +nvt_gmac_setup(struct platform_device *pdev, struct plat_stmmacenet_data *plat)
>>> +{
>>> +	struct device *dev = &pdev->dev;
>>> +	struct nvt_priv_data *bsp_priv;
>>> +	phy_interface_t phy_mode;
>>> +	u32 tx_delay, rx_delay;
>>
>> Please append the unit to the variable name.
> 
> Which is trick, because they are in units of 2000/16 of a picosecond.

Understood. Maybe a comment could be added?


Kind regards,

Paul


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