Re: [PATCH V3 06/11] mfd: bcm2835-pm: Use 'reg-names' to get resources

[Lee Jones <lee.jones@linaro.org>]

On Tue, 07 Jun 2022, Stefan Wahren wrote:

> From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> 
> If available in firmware, find resources by their 'reg-names' position
> instead of relying on hardcoded offsets. Care is taken to support old
> firmware nonetheless.
> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
> Reviewed-by: Peter Robinson <pbrobinson@gmail.com>
> ---
>  drivers/mfd/bcm2835-pm.c | 59 +++++++++++++++++++++++++++-------------
>  1 file changed, 40 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c
> index 42fe67f1538e..ff0dae5a026d 100644
> --- a/drivers/mfd/bcm2835-pm.c
> +++ b/drivers/mfd/bcm2835-pm.c
> @@ -25,9 +25,41 @@ static const struct mfd_cell bcm2835_power_devs[] = {
>  	{ .name = "bcm2835-power" },
>  };
>  
> +static int bcm2835_pm_get_pdata(struct platform_device *pdev,
> +				struct bcm2835_pm *pm)
> +{
> +	/* If no 'reg-names' property is found we can assume we're using old
> +	 * firmware.
> +	 */

Please use the correct format for multi-line comments.

Better still, convert this to a single line comment.

> +	if (!of_find_property(pm->dev->of_node, "reg-names", NULL)) {
> +		dev_warn(pm->dev, "reg-names are missing, please update your DTB.\n");
> +
> +		pm->base = devm_platform_ioremap_resource(pdev, 0);
> +		if (IS_ERR(pm->base))
> +			return PTR_ERR(pm->base);
> +
> +		pm->asb = devm_platform_ioremap_resource(pdev, 1);

Might be nicer to return here and remove the else.

> +	} else {
> +		struct resource *res;
> +
> +		pm->base = devm_platform_ioremap_resource_byname(pdev, "pm");
> +		if (IS_ERR(pm->base))
> +			return PTR_ERR(pm->base);
> +
> +		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> +						    "asb");

While you're at it, might as well make this single line too.

> +		if (res)
> +			pm->asb = devm_ioremap_resource(&pdev->dev, res);
> +	}
> +
> +	if (IS_ERR(pm->asb))
> +		pm->asb = NULL;
> +
> +	return 0;
> +}
> +
>  static int bcm2835_pm_probe(struct platform_device *pdev)
>  {
> -	struct resource *res;
>  	struct device *dev = &pdev->dev;
>  	struct bcm2835_pm *pm;
>  	int ret;
> @@ -39,10 +71,9 @@ static int bcm2835_pm_probe(struct platform_device *pdev)
>  
>  	pm->dev = dev;
>  
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	pm->base = devm_ioremap_resource(dev, res);
> -	if (IS_ERR(pm->base))
> -		return PTR_ERR(pm->base);
> +	ret = bcm2835_pm_get_pdata(pdev, pm);
> +	if (ret)
> +		return ret;
>  
>  	ret = devm_mfd_add_devices(dev, -1,
>  				   bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
> @@ -54,20 +85,10 @@ static int bcm2835_pm_probe(struct platform_device *pdev)
>  	 * bcm2835-pm binding as the key for whether we can reference
>  	 * the full PM register range and support power domains.
>  	 */
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> -	if (res) {
> -		pm->asb = devm_ioremap_resource(dev, res);
> -		if (IS_ERR(pm->asb))
> -			return PTR_ERR(pm->asb);
> -
> -		ret = devm_mfd_add_devices(dev, -1,
> -					   bcm2835_power_devs,
> -					   ARRAY_SIZE(bcm2835_power_devs),
> -					   NULL, 0, NULL);
> -		if (ret)
> -			return ret;
> -	}
> -
> +	if (pm->asb)
> +		return devm_mfd_add_devices(dev, -1, bcm2835_power_devs,
> +					    ARRAY_SIZE(bcm2835_power_devs),
> +					    NULL, 0, NULL);
>  	return 0;
>  }
>  

-- 
Lee Jones [李琼斯]
Principal Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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