Re: [PATCH] ARM: dts: imx6qdl: phycore: Remove emmc vmmc-supply

2019-12-06 Thread Sascha Hauer
On Thu, Dec 05, 2019 at 02:31:53PM +0100, Ahmad Fatoum wrote:
> Hi,
> 
> On 12/5/19 2:08 PM, Stefan Riedmüller wrote:
> > What about regulators that are marked as regulator-always-on but need 
> > voltage adjustments? Or isn't this a real use case for the bootloader?
> 
> If someone absolutely need the voltage adjustments, they'll have to implement
> a proper regulator driver to realize it[1]. The [barebox,]regulator-always-on
> handling I suggest, is only a fallback if there is no regulator found.

What if the driver is present but not yet probed? We would return a
dummy regulator and no longer -EPROBE_DEFER.

Sascha


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Re: [PATCH] ARM: dts: imx6qdl: phycore: Remove emmc vmmc-supply

2019-12-05 Thread Ahmad Fatoum
Hi,

On 12/5/19 2:08 PM, Stefan Riedmüller wrote:
> What about regulators that are marked as regulator-always-on but need voltage 
> adjustments? Or isn't this a real use case for the bootloader?

If someone absolutely need the voltage adjustments, they'll have to implement
a proper regulator driver to realize it[1]. The [barebox,]regulator-always-on
handling I suggest, is only a fallback if there is no regulator found.


Cheers
Ahmad

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Re: [PATCH] ARM: dts: imx6qdl: phycore: Remove emmc vmmc-supply

2019-12-05 Thread Stefan Riedmüller

Hi,

On 05.12.19 09:37, Ahmad Fatoum wrote:

Hello,

On 12/5/19 9:07 AM, Sascha Hauer wrote:

On Tue, Dec 03, 2019 at 02:48:41PM +0100, Stefan Riedmueller wrote:

There is no driver for the eMMC's vmmc-supply regulator in the barebox.
Use a dummy regulator instead by simply deleting the vmmc-supply
property.

Signed-off-by: Stefan Riedmueller 
---
  arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi | 1 +
  1 file changed, 1 insertion(+)

diff --git a/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi 
b/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
index 69f252b42382..974e271f453d 100644
--- a/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
+++ b/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
@@ -112,6 +112,7 @@
  };
  
   {

+   /delete-property/ vmmc-supply;


I don't like this approach very much. It's fine for barebox, but leads
to problems once you start Linux with the barebox device tree. I'd
rather go with the unmodified device trees (apart from the things
barebox changes to the device trees in order to start Linux).


How about a barebox,regulator-always-on property? If the regulator is 
unnecessary,
it basically means you can assume it's always on when barebox runs.

If regulator_get is called with a property that points to such a node, a dummy
regulator is returned with which enable is a no-op. Additionally, do the same
for regulator-always-on, so the in-barebox device tree only needs to mark
non regulator-always-on that are expected to be always on when it runs due to
strapping/fuses as barebox,regulator-always-on.


What about regulators that are marked as regulator-always-on but need 
voltage adjustments? Or isn't this a real use case for the bootloader?


Regards,
Stefan



Thoughts?
Ahmad



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Re: [PATCH] ARM: dts: imx6qdl: phycore: Remove emmc vmmc-supply

2019-12-05 Thread Ahmad Fatoum
Hello,

On 12/5/19 9:07 AM, Sascha Hauer wrote:
> On Tue, Dec 03, 2019 at 02:48:41PM +0100, Stefan Riedmueller wrote:
>> There is no driver for the eMMC's vmmc-supply regulator in the barebox.
>> Use a dummy regulator instead by simply deleting the vmmc-supply
>> property.
>>
>> Signed-off-by: Stefan Riedmueller 
>> ---
>>  arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi 
>> b/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
>> index 69f252b42382..974e271f453d 100644
>> --- a/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
>> +++ b/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
>> @@ -112,6 +112,7 @@
>>  };
>>  
>>   {
>> +/delete-property/ vmmc-supply;
> 
> I don't like this approach very much. It's fine for barebox, but leads
> to problems once you start Linux with the barebox device tree. I'd
> rather go with the unmodified device trees (apart from the things
> barebox changes to the device trees in order to start Linux).

How about a barebox,regulator-always-on property? If the regulator is 
unnecessary,
it basically means you can assume it's always on when barebox runs.

If regulator_get is called with a property that points to such a node, a dummy
regulator is returned with which enable is a no-op. Additionally, do the same
for regulator-always-on, so the in-barebox device tree only needs to mark
non regulator-always-on that are expected to be always on when it runs due to
strapping/fuses as barebox,regulator-always-on.

Thoughts?
Ahmad

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Re: [PATCH] ARM: dts: imx6qdl: phycore: Remove emmc vmmc-supply

2019-12-05 Thread Sascha Hauer
Hi Stefan,

On Tue, Dec 03, 2019 at 02:48:41PM +0100, Stefan Riedmueller wrote:
> There is no driver for the eMMC's vmmc-supply regulator in the barebox.
> Use a dummy regulator instead by simply deleting the vmmc-supply
> property.
> 
> Signed-off-by: Stefan Riedmueller 
> ---
>  arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi 
> b/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
> index 69f252b42382..974e271f453d 100644
> --- a/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
> +++ b/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
> @@ -112,6 +112,7 @@
>  };
>  
>   {
> + /delete-property/ vmmc-supply;

I don't like this approach very much. It's fine for barebox, but leads
to problems once you start Linux with the barebox device tree. I'd
rather go with the unmodified device trees (apart from the things
barebox changes to the device trees in order to start Linux).

One idea that comes to my mind is: Would it be possible to provide a
call like

int regulator_provide_dummy(struct device_node *np);

Boards could call this to let barebox provide a dummy regulator for the
given node (the "dlg,da9062" node in your case) and its child nodes.
In of_regulator_get() we then see if the desired regulator is a child
node of a node registered as dummy provider, then register a dummy
regulator and return it.

Sascha

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[PATCH] ARM: dts: imx6qdl: phycore: Remove emmc vmmc-supply

2019-12-03 Thread Stefan Riedmueller
There is no driver for the eMMC's vmmc-supply regulator in the barebox.
Use a dummy regulator instead by simply deleting the vmmc-supply
property.

Signed-off-by: Stefan Riedmueller 
---
 arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi 
b/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
index 69f252b42382..974e271f453d 100644
--- a/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
+++ b/arch/arm/dts/imx6qdl-phytec-phycore-som.dtsi
@@ -112,6 +112,7 @@
 };
 
  {
+   /delete-property/ vmmc-supply;
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
-- 
2.7.4


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