diff mbox series

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

Message ID 20220515202032.3046-7-stefan.wahren@i2se.com (mailing list archive)
State New, archived
Headers show
Series soc: bcm2835-power: Prepare BCM2711 V3D support | expand

Commit Message

Stefan Wahren May 15, 2022, 8:20 p.m. UTC
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>
---
 drivers/mfd/bcm2835-pm.c | 59 +++++++++++++++++++++++++++-------------
 1 file changed, 40 insertions(+), 19 deletions(-)

Comments

Peter Robinson May 31, 2022, 2:54 p.m. UTC | #1
On Sun, May 15, 2022 at 9:21 PM Stefan Wahren <stefan.wahren@i2se.com> 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.

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/

> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Minor comment inline, else:
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..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?

> +
> +               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
>
Stefan Wahren May 31, 2022, 5:12 p.m. UTC | #2
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@i2se.com> 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.
> 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@suse.de>
>> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
> Minor comment inline, else:
> 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..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
>>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff mbox series

Patch

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");
+
+		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;
 }