[RESEND PATCH v2 02/11] net: dwc_eth_qos: Add option "snps,reset-gpio" phy-rst gpio for stm32

[Patrick DELAUNAY]

Hi David

> From: David Wu <david.wu at rock-chips.com>
> Sent: mardi 12 mai 2020 11:56
> 
> It can be seen that most of the Socs using STM mac, "snps,reset-gpio"
> gpio is used, adding this option makes reset function more general.
> 
> Signed-off-by: David Wu <david.wu at rock-chips.com>
> ---
> 
> Changes in v2:
> - Remove the code is not related (Patrice)
> 
>  drivers/net/dwc_eth_qos.c | 32 +++++++++++++++++++++++++++++++-
>  1 file changed, 31 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/dwc_eth_qos.c b/drivers/net/dwc_eth_qos.c index
> 66a02aa80b..92dab678c7 100644
> --- a/drivers/net/dwc_eth_qos.c
> +++ b/drivers/net/dwc_eth_qos.c
> @@ -314,6 +314,7 @@ struct eqos_priv {
>  	struct eqos_tegra186_regs *tegra186_regs;
>  	struct reset_ctl reset_ctl;
>  	struct gpio_desc phy_reset_gpio;
> +	u32 reset_delays[3];
>  	struct clk clk_master_bus;
>  	struct clk clk_rx;
>  	struct clk clk_ptp_ref;
> @@ -739,6 +740,15 @@ static int eqos_start_resets_stm32(struct udevice *dev)
> 
>  	debug("%s(dev=%p):\n", __func__, dev);
>  	if (dm_gpio_is_valid(&eqos->phy_reset_gpio)) {
> +		ret = dm_gpio_set_value(&eqos->phy_reset_gpio, 0);
> +		if (ret < 0) {
> +			pr_err("dm_gpio_set_value(phy_reset, deassert) failed:
> %d",
> +			       ret);
> +			return ret;
> +		}
> +
> +		udelay(eqos->reset_delays[0]);
> +
>  		ret = dm_gpio_set_value(&eqos->phy_reset_gpio, 1);
>  		if (ret < 0) {
>  			pr_err("dm_gpio_set_value(phy_reset, assert) failed: %d",
> @@ -746,7 +756,7 @@ static int eqos_start_resets_stm32(struct udevice *dev)
>  			return ret;
>  		}
> 
> -		udelay(2);
> +		udelay(eqos->reset_delays[1]);
> 
>  		ret = dm_gpio_set_value(&eqos->phy_reset_gpio, 0);
>  		if (ret < 0) {
> @@ -754,6 +764,8 @@ static int eqos_start_resets_stm32(struct udevice *dev)
>  			       ret);
>  			return ret;
>  		}
> +
> +		udelay(eqos->reset_delays[2]);
>  	}
>  	debug("%s: OK\n", __func__);
> 
> @@ -1864,11 +1876,29 @@ static int eqos_probe_resources_stm32(struct
> udevice *dev)
>  		if (ret)
>  			pr_warn("gpio_request_by_name(phy reset) not provided
> %d",
>  				ret);
> +		else
> +			eqos->reset_delays[1] = 2;
> 
>  		eqos->phyaddr = ofnode_read_u32_default(phandle_args.node,
>  							"reg", -1);
>  	}
> 
> +	if (!dm_gpio_is_valid(&eqos->phy_reset_gpio)) {
> +		int reset_flags = GPIOD_IS_OUT;
> +
> +		if (dev_read_bool(dev, "snps,reset-active-low"))
> +			reset_flags |= GPIOD_ACTIVE_LOW;
> +
> +		ret = gpio_request_by_name(dev, "snps,reset-gpio", 0,
> +					   &eqos->phy_reset_gpio, reset_flags);
> +		if (ret == 0)
> +			ret = dev_read_u32_array(dev, "snps,reset-delays-us",
> +						 eqos->reset_delays, 3);
> +		else
> +			pr_warn("gpio_request_by_name(snps,reset-gpio) failed:
> %d",
> +				ret);
> +	}
> +
>  	debug("%s: OK\n", __func__);
>  	return 0;
> 
> --
> 2.19.1
> 
> 

This obsolete binding isn't expected to be supported in stm32 glue for dwmac
(and it tis the purpose of eqos_stm32_config)

Reference in linux binding
./Documentation/devicetree/bindings/net/stm32-dwmac.txt (the glue)
./Documentation/devicetree/bindings/net/snps,dwmac.yaml

  snps,reset-gpio:
    deprecated: true

  snps,reset-active-low:
    deprecated: true

  snps,reset-delays-us:
    deprecated: true

I expected that gpio reset in future device tree should be managed by only by PHY generic binding 
(upstream in progress on Linux side for STM32MP15x), as described in:

Documentation/devicetree/bindings/net/ethernet-phy.yaml

  reset-gpios:
    maxItems: 1
    description:
      The GPIO phandle and specifier for the PHY reset signal.

  reset-assert-us:
    description:
      Delay after the reset was asserted in microseconds. If this
      property is missing the delay will be skipped.

  reset-deassert-us:
    description:
      Delay after the reset was deasserted in microseconds. If
      this property is missing the delay will be skipped.

See alsoU-Boot: doc/device-tree-bindings/net/phy.txt

Something as 

&mac {
	status = "okay";
	pinctrl-0	= <&ethernet_mii>;
	pinctrl-names	= "default";
	phy-mode	= "mii";
	phy-handle	= <&phy1>;
	mdio0 {
		#address-cells = <1>;
		#size-cells = <0>;
		compatible = "snps,dwmac-mdio";
		phy1: ethernet-phy at 1 {
			reg = <1>; 
+			reset-assert-us = <10000>;
+			reset-deassert-us = <30000>;
+			reset-gpios = <&gpioh 15 GPIO_ACTIVE_LOW>;
		};
	};
};

And this binding "reset-gpios" is supported since the commit 5177b31ba6aa
("net: dwc_eth_qos: implement reset-gpios for stm32")

"reset-assert-us" and "reset-deassert-us" can be added if needed.

For witch product / compatible do you want add the support of this obsolete binding ?

Regards

Patrick