Re: [PATCH net-next v2 15/18] net: macb: Add "mobileye,eyeq5-gem" compatible

[Sean Anderson <sean.anderson@linux.dev>]

On 6/27/25 05:09, Théo Lebrun wrote:
> Add support for the two GEM instances inside Mobileye EyeQ5 SoCs, using
> compatible "mobileye,eyeq5-gem". With it, add a custom init sequence
> that accesses two system-controller registers.
> 
> Noteworthy: NET_IP_ALIGN=2 on MIPS but the hardware does not align and
> low bits aren't configurable, so we cannot respect the requested IP
> header alignment.
> 
> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
> ---
>  drivers/net/ethernet/cadence/macb_main.c | 80 ++++++++++++++++++++++++++++++++
>  1 file changed, 80 insertions(+)
> 
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index f9a3a5caebcafe3d9197a3bc7681b64734d7ac93..ed394e5d1ec9b1748282f1448628d5006f3b0971 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -20,6 +20,7 @@
>  #include <linux/iopoll.h>
>  #include <linux/ip.h>
>  #include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
>  #include <linux/module.h>
>  #include <linux/moduleparam.h>
>  #include <linux/netdevice.h>
> @@ -31,6 +32,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/ptp_classify.h>
> +#include <linux/regmap.h>
>  #include <linux/reset.h>
>  #include <linux/slab.h>
>  #include <linux/tcp.h>
> @@ -4957,6 +4959,72 @@ static int init_reset_optional(struct platform_device *pdev)
>  	return ret;
>  }
>  
> +#define EYEQ5_OLB_GP_TX_SWRST_DIS	BIT(0)		// Tx SW reset
> +#define EYEQ5_OLB_GP_TX_M_CLKE		BIT(1)		// Tx M clock enable
> +#define EYEQ5_OLB_GP_SYS_SWRST_DIS	BIT(2)		// Sys SW reset
> +#define EYEQ5_OLB_GP_SYS_M_CLKE		BIT(3)		// Sys clock enable
> +#define EYEQ5_OLB_GP_SGMII_MODE		BIT(4)		// SGMII mode
> +#define EYEQ5_OLB_GP_RGMII_DRV		GENMASK(8, 5)	// RGMII mode
> +
> +#define EYEQ5_OLB_SGMII_PWR_EN		BIT(0)
> +#define EYEQ5_OLB_SGMII_RST_DIS		BIT(1)
> +#define EYEQ5_OLB_SGMII_PLL_EN		BIT(2)
> +#define EYEQ5_OLB_SGMII_SIG_DET_SW	BIT(3)
> +#define EYEQ5_OLB_SGMII_PWR_STATE	BIT(4)
> +#define EYEQ5_OLB_SGMII_PLL_ACK		BIT(18)
> +
> +static int eyeq5_init(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct net_device *netdev = platform_get_drvdata(pdev);
> +	struct macb *bp = netdev_priv(netdev);
> +	struct device_node *np = dev->of_node;
> +	unsigned int gp, sgmii;
> +	struct regmap *regmap;
> +	unsigned int args[2];
> +	unsigned int reg;
> +	int ret;
> +
> +	regmap = syscon_regmap_lookup_by_phandle_args(np, "mobileye,olb", 2, args);
> +	if (IS_ERR(regmap))
> +		return PTR_ERR(regmap);
> +
> +	gp = args[0];
> +	sgmii = args[1];
> +
> +	/* Forced reset */
> +	regmap_write(regmap, gp, 0);
> +	regmap_write(regmap, sgmii, 0);
> +	usleep_range(5, 20);
> +
> +	if (bp->phy_interface == PHY_INTERFACE_MODE_SGMII) 

Isn't this too early? What if you have an SFP and the interface mode is initially
1000Base-X and the user plugs in an SGMII module?

{
> +		regmap_write(regmap, gp, EYEQ5_OLB_GP_SGMII_MODE);
> +
> +		reg = EYEQ5_OLB_SGMII_PWR_EN | EYEQ5_OLB_SGMII_RST_DIS |
> +		      EYEQ5_OLB_SGMII_PLL_EN;
> +		regmap_write(regmap, sgmii, reg);
> +
> +		ret = regmap_read_poll_timeout(regmap, sgmii, reg,
> +					       reg & EYEQ5_OLB_SGMII_PLL_ACK,
> +					       1, 100);
> +		if (ret)
> +			return dev_err_probe(dev, ret, "PLL timeout");
> +
> +		reg = EYEQ5_OLB_SGMII_PWR_STATE | EYEQ5_OLB_SGMII_SIG_DET_SW;
> +		regmap_update_bits(regmap, sgmii, reg, reg);
> +	}
> +
> +	reg = phy_interface_mode_is_rgmii(bp->phy_interface) ? 0x9 : 0x0;
> +	regmap_update_bits(regmap, gp, EYEQ5_OLB_GP_RGMII_DRV,
> +			   FIELD_PREP(EYEQ5_OLB_GP_RGMII_DRV, reg));
> +
> +	reg = EYEQ5_OLB_GP_TX_SWRST_DIS | EYEQ5_OLB_GP_TX_M_CLKE |
> +	      EYEQ5_OLB_GP_SYS_SWRST_DIS | EYEQ5_OLB_GP_SYS_M_CLKE;
> +	regmap_update_bits(regmap, gp, reg, reg);
> +
> +	return macb_init(pdev);
> +}
> +
>  static const struct macb_usrio_config sama7g5_usrio = {
>  	.mii = 0,
>  	.rmii = 1,
> @@ -5109,6 +5177,17 @@ static const struct macb_config versal_config = {
>  	.usrio = &macb_default_usrio,
>  };
>  
> +static const struct macb_config eyeq5_config = {
> +	.caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE | MACB_CAPS_JUMBO |
> +		MACB_CAPS_GEM_HAS_PTP | MACB_CAPS_QUEUE_DISABLE |
> +		MACB_CAPS_NO_LSO,
> +	.dma_burst_length = 16,
> +	.clk_init = macb_clk_init,
> +	.init = eyeq5_init,
> +	.jumbo_max_len = 10240,
> +	.usrio = &macb_default_usrio,
> +};
> +
>  static const struct of_device_id macb_dt_ids[] = {
>  	{ .compatible = "cdns,at91sam9260-macb", .data = &at91sam9260_config },
>  	{ .compatible = "cdns,macb" },
> @@ -5129,6 +5208,7 @@ static const struct of_device_id macb_dt_ids[] = {
>  	{ .compatible = "microchip,mpfs-macb", .data = &mpfs_config },
>  	{ .compatible = "microchip,sama7g5-gem", .data = &sama7g5_gem_config },
>  	{ .compatible = "microchip,sama7g5-emac", .data = &sama7g5_emac_config },
> +	{ .compatible = "mobileye,eyeq5-gem", .data = &eyeq5_config },
>  	{ .compatible = "xlnx,zynqmp-gem", .data = &zynqmp_config},
>  	{ .compatible = "xlnx,zynq-gem", .data = &zynq_config },
>  	{ .compatible = "xlnx,versal-gem", .data = &versal_config},
>