Re: [for-upstream/dovetail 1/2] drivers/gpio: core: introduce helper to find array of gpiochips

[Florian Bezdeka <florian.bezdeka@siemens.com>]

On 13.05.21 03:02, hongzha1 via Xenomai wrote:
> To find array of gpiochips for non-OF platform
> 
> Signed-off-by: hongzha1 <hongzhan.chen@intel.com>
> ---
>  include/cobalt/kernel/rtdm/gpio.h |  4 ++++
>  kernel/drivers/gpio/gpio-core.c   | 19 +++++++++++++++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/include/cobalt/kernel/rtdm/gpio.h b/include/cobalt/kernel/rtdm/gpio.h
> index c5fb20f25..99772f558 100644
> --- a/include/cobalt/kernel/rtdm/gpio.h
> +++ b/include/cobalt/kernel/rtdm/gpio.h
> @@ -64,6 +64,10 @@ int rtdm_gpiochip_post_event(struct rtdm_gpio_chip *rgc,
>  int rtdm_gpiochip_find(struct device_node *from,
>  			  const char *label, int type);
>  
> +int rtdm_gpiochip_array_find(struct device_node *from,
> +				const char *compat[],
> +				int nentries, int type);
> +
>  #ifdef CONFIG_OF
>  
>  int rtdm_gpiochip_scan_of(struct device_node *from,
> diff --git a/kernel/drivers/gpio/gpio-core.c b/kernel/drivers/gpio/gpio-core.c
> index b3d801fa1..20a6d7875 100644
> --- a/kernel/drivers/gpio/gpio-core.c
> +++ b/kernel/drivers/gpio/gpio-core.c
> @@ -543,6 +543,25 @@ int rtdm_gpiochip_find(struct device_node *from, const char *label,
>  }
>  EXPORT_SYMBOL_GPL(rtdm_gpiochip_find);
>  
> +int rtdm_gpiochip_array_find(struct device_node *from,
> +				const char *compat[],
> +				int nentries, int type)
> +{
> +	int ret = -ENODEV, _ret, n;
> +
> +	for (n = 0; n < nentries; n++) {
> +		_ret = rtdm_gpiochip_find(from, compat[n], type);
> +		if (_ret) {
> +			if (_ret != -ENODEV)
> +				return _ret;
> +		} else
> +			ret = 0;
> +	}
> +
> +	return ret;
> +}

I'm not sure if I completely understand the code, but maybe it could be
simplified to:

{
	int ret, n;

	for (n = 0; n < nentries; n++) {
		ret = rtdm_gpiochip_find(from, compat[n], type);

		if (ret && ret != -ENODEV)
			break;
	}

	return ret;
}

> +EXPORT_SYMBOL_GPL(rtdm_gpiochip_array_find);
> +
>  #ifdef CONFIG_OF
>  
>  #include <linux/of_platform.h>
> 


-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux