Re: [RFC 06/10] pcie: starfive: Add a optional power gpio support

[E Shattow <e@freeshell.de>]

On 8/28/25 23:09, Hal Feng wrote:
> Get a optional power gpio and enable it if it is valid.
> 

I see this appears to be a normal thing that needs implemented in U-Boot
to have parity with Linux kernel, but the commit message should help me
understand why so I don't have to think so hard.

Expand why this is useful and how this is implemented in Linux kernel,
what is the API reference or something to give reason why U-Boot can
expect the devicetree property to be present from upstream
devicetree-rebasing.

> Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
> ---
>  drivers/pci/pcie_starfive_jh7110.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/pci/pcie_starfive_jh7110.c b/drivers/pci/pcie_starfive_jh7110.c
> index 51aca7359ff..f6b50d12a90 100644
> --- a/drivers/pci/pcie_starfive_jh7110.c
> +++ b/drivers/pci/pcie_starfive_jh7110.c
> @@ -45,6 +45,7 @@ struct starfive_pcie {
>  	struct pcie_plda plda;
>  	struct clk_bulk	clks;
>  	struct reset_ctl_bulk	rsts;
> +	struct gpio_desc	power_gpio;
>  	struct gpio_desc	reset_gpio;
>  	struct regmap *regmap;
>  	unsigned int stg_pcie_base;
> @@ -184,6 +185,10 @@ static int starfive_pcie_parse_dt(struct udevice *dev)
>  		dev_err(dev, "reset-gpio is not valid\n");
>  		return -EINVAL;
>  	}
> +
> +	gpio_request_by_name(dev, "enable-gpios", 0, &priv->power_gpio,
> +			     GPIOD_IS_OUT);
> +
>  	return 0;
>  }
>  
> @@ -205,6 +210,9 @@ static int starfive_pcie_init_port(struct udevice *dev)
>  		goto err_deassert_clk;
>  	}
>  
> +	if (dm_gpio_is_valid(&priv->power_gpio))
> +		dm_gpio_set_value(&priv->power_gpio, 1);
> +
>  	dm_gpio_set_value(&priv->reset_gpio, 1);
>  	/* Disable physical functions except #0 */
>  	for (i = 1; i < PLDA_FUNC_NUM; i++) {

-E