[U-Boot] [PATCH v2 6/6] arm: mvebu: helios4: Reset uSOM onboard phy during board init

[Stefan Roese]

On 04.12.18 16:37, Aditya Prayoga wrote:

<snip>

>>>> Yes. As mentioned above, please look at the mvpp2 driver. And e.g.
>>>> at the armada-8040-clearfog-gt-8k.dts DT file:
>>>>
>>>> /* 1G SGMII */
>>>> &cps_eth1 {
>>>>          status = "okay";
>>>>          phy-mode = "sgmii";
>>>>          phy = <&phy0>;
>>>>          phy-reset-gpios = <&cpm_gpio1 11 GPIO_ACTIVE_LOW>;
>>>> };
>>>>
>>>> Here you see, how the GPIO is defined in the DT. It should not
>>>> be too hard to get this implemented in the mvneta driver as well.
>>>>
>>> Yes, what I meant is to put "phy-reset-gpios" in the device tree but it
>>> would still part of the system reset so the reset would be asserted in
>>> board_init.
>>>
>>> If the reset implemented in driver (mvneta), the reset would only
>>> asserted when u-boot going to use the network interface. This is not
>>> desirable.
>>
>> Network device probe routine is always called even when not used. See this

This is not correct. The probe function is *not* always called - at least
not in newer DM drivers.

>> comment in eth_initialize():
>>
>>          /*
>>           * Devices need to write the hwaddr even if not started so that Linux
>>           * will have access to the hwaddr that u-boot stored for the device.
>>           * This is accomplished by attempting to probe each device and calling
>>           * their write_hwaddr() operation.
>>           */
>>

These are special hooks that are always called to write the MAC address,
even when the device is not used in U-Boot. IIRC, the bind() function
is also always called.

> That is what I thought but that is not what I observed.
> I tried to port that mvpp2 changes to mvneta
> ---
> diff --git a/drivers/net/mvneta.c b/drivers/net/mvneta.c
> index 8cb04b5..34f191d 100644
> --- a/drivers/net/mvneta.c
> +++ b/drivers/net/mvneta.c
> @@ -27,6 +27,7 @@
>   #include <asm/arch/soc.h>
>   #include <linux/compat.h>
>   #include <linux/mbus.h>
> +#include <asm-generic/gpio.h>
> 
>   DECLARE_GLOBAL_DATA_PTR;
> 
> @@ -274,6 +275,9 @@ struct mvneta_port {
>       int init;
>       int phyaddr;
>       struct phy_device *phydev;
> +#ifdef CONFIG_DM_GPIO
> +    struct gpio_desc phy_reset_gpio;
> +#endif
>       struct mii_dev *bus;
>   };
> 
> @@ -1733,6 +1737,17 @@ static int mvneta_probe(struct udevice *dev)
>           pp->phyaddr = fdtdec_get_int(blob, addr, "reg", 0);
>       }
> 
> +#ifdef CONFIG_DM_GPIO
> +    gpio_request_by_name(dev, "phy-reset-gpios", 0,
> +                 &pp->phy_reset_gpio, GPIOD_IS_OUT);
> +
> +    if (dm_gpio_is_valid(&pp->phy_reset_gpio)) {
> +        dm_gpio_set_value(&pp->phy_reset_gpio, 1);
> +        mdelay(3000);
> +        dm_gpio_set_value(&pp->phy_reset_gpio, 0);
> +    }
> +#endif
> +
>       bus = mdio_alloc();
>       if (!bus) {
>           printf("Failed to allocate MDIO bus\n");
> ---
> I intentionally put that 3 seconds delay so i can observe the
> RJ45 LED. After pressing the reset button, the LED never turned off.
> It turned off only when i access the network, for example tftpboot.
> 
> here are snippet from the serial log
> ----
> Net:
> Warning: ethernet at 70000 (eth1) using random MAC address - ae:c1:5a:4e:ba:00
> eth1: ethernet at 70000
> Hit any key to stop autoboot:  0
> => tftpboot
> ethernet at 70000 Waiting for PHY auto negotiation to complete....... done
> *** ERROR: `serverip' not set
> =>
> ----
> The LED turned off during "Waiting for PHY auto negotiation"

This should work. Did you correctly add the GPIO to your DT? Is the
GPIO correctly referenced? Did you check this in the GPIO driver?

Thanks,
Stefan