[PATCH 0/2] Apple mailbox fixup: switch to generic compatibles

[PATCH 0/2] Apple mailbox fixup: switch to generic compatibles

[Hector Martin]

Hi folks,

Just a quick fix for the Apple mailbox compatible. Similar to [1], we
intend to use SoC-specific compatibles only for potential quirks, and
rely on a generic compatible to allow for forward-compatibility as long
as things don't break.

Since this isn't instantiated in any upstream DT yet, I think we can
afford the compatibility break now.

This also goes ahead and adds the compatible for the new t600x SoCs.

[1] https://lore.kernel.org/linux-arm-kernel/20211121171545.27402-3-j@jannau.net/

Hector Martin (2):
  dt-bindings: mailbox: apple,mailbox: Add generic and t6000 compatibles
  mailbox: apple: Bind to generic compatibles

 .../devicetree/bindings/mailbox/apple,mailbox.yaml   | 12 +++++++++---
 drivers/mailbox/apple-mailbox.c                      |  4 ++--
 2 files changed, 11 insertions(+), 5 deletions(-)

-- 
2.33.0

[PATCH 1/2] dt-bindings: mailbox: apple,mailbox: Add generic and t6000 compatibles

[Hector Martin]

Much as we've done with other blocks, let's introduce generic
compatibles so drivers can bind to those and still work with future
SoCs, as long as the hardware remains the same. Also go ahead and add
compatibles for the new t600x SoCs (we group those as t6000).

Note that no DTs instantiate devices with this binding yet.

Signed-off-by: Hector Martin <marcan@marcan.st>
---
 .../devicetree/bindings/mailbox/apple,mailbox.yaml   | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml b/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
index 2c1704b34e7a..58007c789671 100644
--- a/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
+++ b/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
@@ -27,14 +27,20 @@ properties:
           for example for the display controller, the system management
           controller and the NVMe coprocessor.
         items:
-          - const: apple,t8103-asc-mailbox
+          - enum:
+              - apple,t8103-asc-mailbox
+              - apple,t6000-asc-mailbox
+          - const: apple,asc-mailbox
 
       - description:
           M3 mailboxes are an older variant with a slightly different MMIO
           interface still found on the M1. It is used for the Thunderbolt
           co-processors.
         items:
-          - const: apple,t8103-m3-mailbox
+          - enum:
+              - apple,t8103-m3-mailbox
+              - apple,t6000-m3-mailbox
+          - const: apple,m3-mailbox
 
   reg:
     maxItems: 1
@@ -68,7 +74,7 @@ additionalProperties: false
 examples:
   - |
         mailbox@77408000 {
-                compatible = "apple,t8103-asc-mailbox";
+                compatible = "apple,t8103-asc-mailbox", "apple,asc-mailbox";
                 reg = <0x77408000 0x4000>;
                 interrupts = <1 583 4>, <1 584 4>, <1 585 4>, <1 586 4>;
                 interrupt-names = "send-empty", "send-not-empty",
-- 
2.33.0

[PATCH 2/2] mailbox: apple: Bind to generic compatibles

[Hector Martin]

As with other blocks, we intend to have drivers bind to generic
compatibles as long as there are no SoC-specific quirks. This allows
forward-compatibility with future SoCs.

No upstream DTs instantiate this yet, so it's still safe to make this
breaking change.

Signed-off-by: Hector Martin <marcan@marcan.st>
---
 drivers/mailbox/apple-mailbox.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mailbox/apple-mailbox.c b/drivers/mailbox/apple-mailbox.c
index 72942002a54a..f9704332cda3 100644
--- a/drivers/mailbox/apple-mailbox.c
+++ b/drivers/mailbox/apple-mailbox.c
@@ -364,8 +364,8 @@ static const struct apple_mbox_hw apple_mbox_m3_hw = {
 };
 
 static const struct of_device_id apple_mbox_of_match[] = {
-	{ .compatible = "apple,t8103-asc-mailbox", .data = &apple_mbox_asc_hw },
-	{ .compatible = "apple,t8103-m3-mailbox", .data = &apple_mbox_m3_hw },
+	{ .compatible = "apple,asc-mailbox", .data = &apple_mbox_asc_hw },
+	{ .compatible = "apple,m3-mailbox", .data = &apple_mbox_m3_hw },
 	{}
 };
 MODULE_DEVICE_TABLE(of, apple_mbox_of_match);
-- 
2.33.0

Re: [PATCH 1/2] dt-bindings: mailbox: apple, mailbox: Add generic and t6000 compatibles

[Mark Kettenis]

> From: Hector Martin <marcan@marcan.st>
> Date: Thu,  9 Dec 2021 14:50:48 +0900
> 
> Much as we've done with other blocks, let's introduce generic
> compatibles so drivers can bind to those and still work with future
> SoCs, as long as the hardware remains the same. Also go ahead and add
> compatibles for the new t600x SoCs (we group those as t6000).
> 
> Note that no DTs instantiate devices with this binding yet.

I think this makes sense.  There is no OpenBSD driver for this yet and
my U-Boot driver has not been submitted upstream yet.  So I think
there are no real backwards compatibility issues.

Reviewed-by: Mark Kettenis <kettenis@openbsd.org>

>
> Signed-off-by: Hector Martin <marcan@marcan.st>
> ---
>  .../devicetree/bindings/mailbox/apple,mailbox.yaml   | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml b/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
> index 2c1704b34e7a..58007c789671 100644
> --- a/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
> +++ b/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
> @@ -27,14 +27,20 @@ properties:
>            for example for the display controller, the system management
>            controller and the NVMe coprocessor.
>          items:
> -          - const: apple,t8103-asc-mailbox
> +          - enum:
> +              - apple,t8103-asc-mailbox
> +              - apple,t6000-asc-mailbox
> +          - const: apple,asc-mailbox
>  
>        - description:
>            M3 mailboxes are an older variant with a slightly different MMIO
>            interface still found on the M1. It is used for the Thunderbolt
>            co-processors.
>          items:
> -          - const: apple,t8103-m3-mailbox
> +          - enum:
> +              - apple,t8103-m3-mailbox
> +              - apple,t6000-m3-mailbox
> +          - const: apple,m3-mailbox
>  
>    reg:
>      maxItems: 1
> @@ -68,7 +74,7 @@ additionalProperties: false
>  examples:
>    - |
>          mailbox@77408000 {
> -                compatible = "apple,t8103-asc-mailbox";
> +                compatible = "apple,t8103-asc-mailbox", "apple,asc-mailbox";
>                  reg = <0x77408000 0x4000>;
>                  interrupts = <1 583 4>, <1 584 4>, <1 585 4>, <1 586 4>;
>                  interrupt-names = "send-empty", "send-not-empty",
> -- 
> 2.33.0
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 

Re: [PATCH 0/2] Apple mailbox fixup: switch to generic compatibles

[Sven Peter]

On Thu, Dec 9, 2021, at 06:50, Hector Martin wrote:
> Hi folks,
>
> Just a quick fix for the Apple mailbox compatible. Similar to [1], we
> intend to use SoC-specific compatibles only for potential quirks, and
> rely on a generic compatible to allow for forward-compatibility as long
> as things don't break.

I vaguely remember a brief discussion about this and I think we thought about
using "t6000-asc", "t8103-asc" in this case since this specific mailbox hardware
was only introduced in the M1. I think Apple calls this variant ascwrap-v4
and m3wrap-v2.

Doing it like you suggested is also fine with me though.


Sven

Re: [PATCH 0/2] Apple mailbox fixup: switch to generic compatibles

[Hector Martin]

On 10/12/2021 01.33, Sven Peter wrote:
> On Thu, Dec 9, 2021, at 06:50, Hector Martin wrote:
>> Hi folks,
>>
>> Just a quick fix for the Apple mailbox compatible. Similar to [1], we
>> intend to use SoC-specific compatibles only for potential quirks, and
>> rely on a generic compatible to allow for forward-compatibility as long
>> as things don't break.
> 
> I vaguely remember a brief discussion about this and I think we thought about
> using "t6000-asc", "t8103-asc" in this case since this specific mailbox hardware
> was only introduced in the M1. I think Apple calls this variant ascwrap-v4
> and m3wrap-v2.
> 
> Doing it like you suggested is also fine with me though.

I think I remember that one... seems this is ascwrap-v4 in t8101 too, so 
not quite introduced with M1. But that one doesn't have m3wraps (or 
doesn't use them).

Since Apple do have some kind of sane versioning for these it seems, 
maybe we should follow their numbers and call them apple,asc-mailbox-v4 
and apple,m3-mailbox-v2?

-- 
Hector Martin (marcan@marcan.st)
Public Key: https://mrcn.st/pub

Re: [PATCH 0/2] Apple mailbox fixup: switch to generic compatibles

[Sven Peter]

On Mon, Dec 13, 2021, at 04:55, Hector Martin wrote:
> On 10/12/2021 01.33, Sven Peter wrote:
>> On Thu, Dec 9, 2021, at 06:50, Hector Martin wrote:
>>> Hi folks,
>>>
>>> Just a quick fix for the Apple mailbox compatible. Similar to [1], we
>>> intend to use SoC-specific compatibles only for potential quirks, and
>>> rely on a generic compatible to allow for forward-compatibility as long
>>> as things don't break.
>> 
>> I vaguely remember a brief discussion about this and I think we thought about
>> using "t6000-asc", "t8103-asc" in this case since this specific mailbox hardware
>> was only introduced in the M1. I think Apple calls this variant ascwrap-v4
>> and m3wrap-v2.
>> 
>> Doing it like you suggested is also fine with me though.
>
> I think I remember that one... seems this is ascwrap-v4 in t8101 too, so 
> not quite introduced with M1. But that one doesn't have m3wraps (or 
> doesn't use them).
>
> Since Apple do have some kind of sane versioning for these it seems, 
> maybe we should follow their numbers and call them apple,asc-mailbox-v4 
> and apple,m3-mailbox-v2?

Sure, sounds good to me.


Sven

Re: [PATCH 1/2] dt-bindings: mailbox: apple,mailbox: Add generic and t6000 compatibles

[Rob Herring]

On Thu, 09 Dec 2021 14:50:48 +0900, Hector Martin wrote:
> Much as we've done with other blocks, let's introduce generic
> compatibles so drivers can bind to those and still work with future
> SoCs, as long as the hardware remains the same. Also go ahead and add
> compatibles for the new t600x SoCs (we group those as t6000).
> 
> Note that no DTs instantiate devices with this binding yet.
> 
> Signed-off-by: Hector Martin <marcan@marcan.st>
> ---
>  .../devicetree/bindings/mailbox/apple,mailbox.yaml   | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH 1/2] dt-bindings: mailbox: apple,mailbox: Add generic and t6000 compatibles

[Sven Peter]

On Thu, Dec 9, 2021, at 06:50, Hector Martin wrote:
> Much as we've done with other blocks, let's introduce generic
> compatibles so drivers can bind to those and still work with future
> SoCs, as long as the hardware remains the same. Also go ahead and add
> compatibles for the new t600x SoCs (we group those as t6000).
>
> Note that no DTs instantiate devices with this binding yet.
>
> Signed-off-by: Hector Martin <marcan@marcan.st>
> ---
Reviewed-by: Sven Peter <sven@svenpeter.dev>

Re: [PATCH 1/2] dt-bindings: mailbox: apple,mailbox: Add generic and t6000 compatibles

[Sven Peter]

On Wed, Dec 15, 2021, at 18:13, Sven Peter wrote:
> On Thu, Dec 9, 2021, at 06:50, Hector Martin wrote:
>> Much as we've done with other blocks, let's introduce generic
>> compatibles so drivers can bind to those and still work with future
>> SoCs, as long as the hardware remains the same. Also go ahead and add
>> compatibles for the new t600x SoCs (we group those as t6000).
>>
>> Note that no DTs instantiate devices with this binding yet.
>>
>> Signed-off-by: Hector Martin <marcan@marcan.st>
>> ---
> Reviewed-by: Sven Peter <sven@svenpeter.dev>

er... wait... that was meant for v2, sorry *sigh*.


Sven