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

[Stefan Wahren]

Hi Peter,

Am 31.05.22 um 16:54 schrieb Peter Robinson:
> On Sun, May 15, 2022 at 9:21 PM Stefan Wahren <stefan.wahren at i2se.com> wrote:
>> From: Nicolas Saenz Julienne <nsaenzjulienne at 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.
> So this patch has changed a little over Nicolas's last one, which was
> what I based my patch on [1] but there's no changelog
>
> [1] https://patchwork.kernel.org/project/linux-arm-kernel/patch/20220213225646.67761-7-pbrobinson@gmail.com/

yes my favorite changelog style is "within the cover letter". Since i 
started a new and split out series a version reference doesn't make 
sense. But yes, very unfortunate for a reviewer. Keeping the version 
number would have been better.

Here the changes since v4 afterwards:

- fix copy & paste issue in else branch
- don't use devm_platform_ioremap_resource_byname for optional register 
to avoid confusing log error
- pull out asb handling to avoid copy & paste

>
>> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>
>> Signed-off-by: Stefan Wahren <stefan.wahren at i2se.com>
> Minor comment inline, else:
> Reviewed-by: Peter Robinson <pbrobinson at 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..1656d786993a 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.
>> +        */
>> +       if (!of_find_property(pm->dev->of_node, "reg-names", NULL)) {
>> +               dev_warn(pm->dev, "Old devicetree detected, please update your firmware.\n");
> If they're using an upstream kernel DT and an old firmware this may be
> confusing, maybe tweak the wording a little?

"reg-names are missing, please update your DTB.\ņ"

>> +               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);
>> +       } 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");
>> +               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;
>>   }
>>
>> --
>> 2.25.1
>>
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