Re: [PATCH] gpio: pca953x: Add GPIO settle delay

[Francesco Dolcini <francesco@dolcini.it>]

Hello Judith,

On Fri, Jul 10, 2026 at 06:04:09PM -0500, Judith Mendez wrote:
> Some board designs have slow RC circuits on GPIO outputs controlled by
> PCA953X I2C expanders. On some board designs, pin voltage transitions
> can take significant time after I2C write command completes.
> 
> Add an optional "gpio-settle-delay-ms" device tree property for the
> pca953x driver to add a delay after I2C write if specified, allowing to
> compensate for slow RC circuits.
> 
> Signed-off-by: Judith Mendez <jm@ti.com>
> ---
>  drivers/gpio/pca953x_gpio.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpio/pca953x_gpio.c b/drivers/gpio/pca953x_gpio.c
> index 965a5fcf30b..54b957069c9 100644
> --- a/drivers/gpio/pca953x_gpio.c
> +++ b/drivers/gpio/pca953x_gpio.c
> @@ -333,6 +339,8 @@ static int pca953x_probe(struct udevice *dev)
>  
>  	info->bank_count = DIV_ROUND_UP(info->gpio_count, BANK_SZ);
>  
> +	info->settle_delay_ms = dev_read_u32_default(dev, "gpio-settle-delay-ms", 0);

Is this property supported also in Linux and defined in the Linux
binding? I do not think we should have U-Boot specific DT properties.

Francesco