[Linux-stm32] [PATCH] net: stmmac: Support gpio high-level reset for devices requiring it

[lizhe]

Hi，

     

  if i add the following code to this function, the gpio outputs a high level

  without this code, it outputs a low level, 
  the function currently drivers the reset GPIO to a low state, failing to account 

  for devices requiring an active-high reset.




  i invited our hardware engineer to  measure the voltage level on this GPIO pin,

  without  adding this code, the voltage at this GPIO pin remains at 0V




  +             int current_value;




  +             keep_high = device_property_read_bool(priv->device,

  +                                                             "snps,reset-keep-high");

  +              if (keep_high) {

  +                     gpiod_set_value_cansleep(reset_gpio, 1);

  +                      current_value = gpiod_get_value_cansleep(reset_gpio);

  +                      pr_info("current_value: %d\n", current_value);

  +              }

   in the RK3588 system, i am using ,there are many DTS node configured link this:

    snps, reset-gpio = <&gpioX RK_PXX GPIO_ACTIVE_HIGH>;   
    All of them correctly parse the GPIO pin's state are described in the DTS







Thx !

Lizhe








At 2025-07-09 22:29:46, "Russell King (Oracle)" <linux at armlinux.org.uk> wrote:
>On Wed, Jul 09, 2025 at 07:42:55PM +0800, lizhe wrote:
>> Hi,
>>     i have already declared it in the DTS.
>> 
>>     &gmac {
>>             snps,reset-gpio = <&gpio3 RK_PB7 GPIO_ACTIVE_HIGH>;
>>     };
>
>Active high means that the reset is in effect when the output is at the
>logic '1' state. So, gpiod_get_value*() will return the same as
>gpiod_get_raw_value*().
>
>Active low means that the reset is in effect when the output is at the
>logic '0' state, and in that case the return value of
>gpiod_get_value*() will return true when the reset is active (at logic
>'0' state) whereas gpiod_get_raw_value*() will return zero.
>
>-- 
>RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
>FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
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