Re: [PATCH RFT] pci: imx: Properly support upstream Linux reset-gpios property

[Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>]

On 13/03/2026 09:12, Max Merchel wrote:
> 
> On 3/12/26 20:26, Krzysztof Kozlowski wrote:
>> The driver requests explicitly "reset-gpio" property, not the one with
>> "gpios" suffix but upstream Linux kernel deprecated it in 2021.
>> Existing upstream Linux kernel DTS is being changed to "reset-gpios"
>> property, thus update the driver to read that one too.
>>
>> Note that driver is probably broken already, because it parsed GPIO in
>> standard way respecting the flags and on top of that applied the
>> "reset-gpio-active-high" flag, thus "reset-gpio ACTIVE_LOW" with the
>> "reset-gpio-active-high" property would be double inverted.
>>
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
>>
>> ---
>>
>> 1. https://lore.kernel.org/linux-devicetree/20260312-dts-snps-reset-gpios-v2-12-0d5040eb4a1e@oss.qualcomm.com/
>> 2. See Linux kernel commit 42694f9f6407 ("dt-bindings: PCI: add snps,dw-pcie.yaml")
>> ---
>>   drivers/pci/pcie_imx.c | 22 +++++++++++++++++++---
>>   1 file changed, 19 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/pci/pcie_imx.c b/drivers/pci/pcie_imx.c
>> index 11c4ccbfc555..8d853ecf2c22 100644
>> --- a/drivers/pci/pcie_imx.c
>> +++ b/drivers/pci/pcie_imx.c
>> @@ -728,15 +728,31 @@ static int imx_pcie_dm_write_config(struct udevice *dev, pci_dev_t bdf,
>>   static int imx_pcie_dm_probe(struct udevice *dev)
>>   {
>>   	struct imx_pcie_priv *priv = dev_get_priv(dev);
>> +	int ret;
>>   
>>   #if CONFIG_IS_ENABLED(DM_REGULATOR)
>>   	device_get_supply_regulator(dev, "vpcie-supply", &priv->vpcie);
>>   #endif
>>   
>>   	/* if PERST# valid from dt then assert it */
>> -	gpio_request_by_name(dev, "reset-gpio", 0, &priv->reset_gpio,
>> -			     GPIOD_IS_OUT);
>> -	priv->reset_active_high = dev_read_bool(dev, "reset-gpio-active-high");
>> +	ret = gpio_request_by_name(dev, "reset-gpio", 0, &priv->reset_gpio,
>> +				   GPIOD_IS_OUT);
>> +	if (!ret) {
>> +		/*
>> +		 * Legacy property, invert assert logic based on
>> +		 * reset-gpio-active-high. This won't work if flags are not
>> +		 * matching the reset-gpio-active-high.
>> +		 */
>> +		priv->reset_active_high = dev_read_bool(dev, "reset-gpio-active-high");
> 
> A warning should also be issued when using the deprecated "reset-gpio" 
> property.
> 
>              dev_warn(dev, "reset-gpio property deprecated, use 
> reset-gpios\n");
> 
Why? What would end user seeing this in their serial console do? The
deprecated property is not a mistake, it's just deprecated.

Best regards,
Krzysztof