Re: [PATCH net-next 3/3] net: stmmac: Add glue layer for Spacemit K3 SoC

[Inochi Amaoto <inochiama@gmail.com>]

On Tue, Jan 20, 2026 at 04:56:32AM +0000, Russell King (Oracle) wrote:
> On Tue, Jan 20, 2026 at 12:36:08PM +0800, Inochi Amaoto wrote:
> > Adds Spacemit dwmac driver support on the Spacemit K3 SoC.
> 
> Some more information would be useful. E.g. describing why you need to
> fix the RGMII mode.
> 

OK. I will add this.

> > +/* ctrl register bits */
> > +#define PHY_INTF_RGMII			BIT(3)
> > +#define PHY_INTF_MII			BIT(4)
> > +
> > +#define WAKE_IRQ_EN			BIT(9)
> > +#define PHY_IRQ_EN			BIT(12)
> > +
> > +/* dline register bits */
> > +#define RGMII_RX_DLINE_EN		BIT(0)
> > +#define RGMII_RX_DLINE_STEP		GENMASK(5, 4)
> > +#define RGMII_RX_DLINE_CODE		GENMASK(15, 8)
> > +#define RGMII_TX_DLINE_EN		BIT(16)
> > +#define RGMII_TX_DLINE_STEP		GENMASK(21, 20)
> > +#define RGMII_TX_DLINE_CODE		GENMASK(31, 24)
> > +
> > +#define MAX_DLINE_DELAY_CODE		0xff
> > +
> > +struct spacemit_dwmac {
> > +	struct device *dev;
> > +	struct clk *tx;
> > +};
> 
> This structure seems unused.
> 

Yeah, I forgot this, will remove in the next version.

> > +
> > +/* Note: the delay step value is at 0.1ps */
> > +static const unsigned int k3_delay_step_10x[4] = {
> > +	367, 493, 559, 685
> > +};
> > +
> > +static int spacemit_dwmac_set_delay(struct regmap *apmu,
> > +				    unsigned int dline_offset,
> > +				    unsigned int tx_code, unsigned int tx_config,
> > +				    unsigned int rx_code, unsigned int rx_config)
> > +{
> > +	unsigned int mask, val;
> > +
> > +	mask = RGMII_RX_DLINE_STEP | RGMII_TX_DLINE_CODE | RGMII_TX_DLINE_EN |
> > +	       RGMII_TX_DLINE_STEP | RGMII_RX_DLINE_CODE | RGMII_RX_DLINE_EN;
> > +	val = FIELD_PREP(RGMII_TX_DLINE_CODE, tx_config) |
> > +	      FIELD_PREP(RGMII_TX_DLINE_CODE, tx_code) | RGMII_TX_DLINE_EN |
> > +	      FIELD_PREP(RGMII_TX_DLINE_CODE, rx_config) |
> > +	      FIELD_PREP(RGMII_RX_DLINE_CODE, rx_code) | RGMII_RX_DLINE_EN;
> 
> These FIELD_PREP() fields look wrong. Did you mean to use DLINE_CODE
> both tx_config and tx_code, and did you mean to use TX_DLINE_CODE for
> rx_config ?
> 

This should be RGMII_TX_DLINE_CODE. This is a copy paste error, I
will fix it.

> > +	plat_dat->clk_tx_i = devm_clk_get_enabled(&pdev->dev, "tx");
> > +	if (IS_ERR(plat_dat->clk_tx_i))
> > +		return dev_err_probe(&pdev->dev, PTR_ERR(plat_dat->clk_tx_i),
> > +				     "failed to get tx clock\n");
> 
> You set plat_dat->clk_tx_i, but you don't point
> plat_dat->set_clk_tx_rate at anything, which means the stmmac core
> does nothing with this.
> 

Yes, the vendor told me that the internal tx clock rate will be auto
changed when the speed rate is changed. So no software interaction
is needed.

> Given the last two points, has RGMII mode been tested on this
> hardware?
> 

In fact I only tested the rgmii-id, which does not change the internal
id. I will try the rgmii mode.

Regards,
Inochi