On Wed, Apr 24, 2024 at 07:21:51PM +0200, Luca Weiss wrote:
> The qcom,ipc-N properties are essentially providing a reference to a
> mailbox, so allow using the mboxes property to do the same in a more
> structured way.
Can we mark qcom,ipc-N as deprecated then?
> Since multiple SMSM hosts are supported, we need to be able to provide
> the correct mailbox for each host. The old qcom,ipc-N properties map to
> the mboxes property by index, starting at 0 since that's a valid SMSM
> host also.
>
> The new example shows how an smsm node with just qcom,ipc-3 should be
> specified with the mboxes property.
>
> Signed-off-by: Luca Weiss <[email protected]>
> ---
> .../devicetree/bindings/soc/qcom/qcom,smsm.yaml | 48 ++++++++++++++++++----
> 1 file changed, 40 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> index db67cf043256..b12589171169 100644
> --- a/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> @@ -33,6 +33,13 @@ properties:
> specifier of the column in the subscription matrix representing the local
> processor.
>
> + mboxes:
> + minItems: 1
> + maxItems: 5
Need to define what each entry is.
> + description:
> + Reference to the mailbox representing the outgoing doorbell in APCS for
> + this client.
> +
> '#size-cells':
> const: 0
>
> @@ -98,15 +105,18 @@ required:
> - '#address-cells'
> - '#size-cells'
>
> -anyOf:
> +oneOf:
> - required:
> - - qcom,ipc-1
> - - required:
> - - qcom,ipc-2
> - - required:
> - - qcom,ipc-3
> - - required:
> - - qcom,ipc-4
> + - mboxes
> + - anyOf:
> + - required:
> + - qcom,ipc-1
> + - required:
> + - qcom,ipc-2
> + - required:
> + - qcom,ipc-3
> + - required:
> + - qcom,ipc-4
>
> additionalProperties: false
>
> @@ -136,3 +146,25 @@ examples:
> #interrupt-cells = <2>;
> };
> };
> + # Example using mboxes property
> + - |
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> + shared-memory {
> + compatible = "qcom,smsm";
> + #address-cells = <1>;
> + #size-cells = <0>;
> + mboxes = <0>, <0>, <0>, <&apcs 19>;
> +
> + apps@0 {
> + reg = <0>;
> + #qcom,smem-state-cells = <1>;
> + };
> +
> + wcnss@7 {
> + reg = <7>;
> + interrupts = <GIC_SPI 144 IRQ_TYPE_EDGE_RISING>;
> + interrupt-controller;
> + #interrupt-cells = <2>;
> + };
> + };
>
> --
> 2.44.0
>
On Donnerstag, 25. April 2024 18:17:15 MESZ Rob Herring wrote:
> On Wed, Apr 24, 2024 at 07:21:51PM +0200, Luca Weiss wrote:
> > The qcom,ipc-N properties are essentially providing a reference to a
> > mailbox, so allow using the mboxes property to do the same in a more
> > structured way.
>
> Can we mark qcom,ipc-N as deprecated then?
Yes, that should be ok. Will also send a similar change to the other bindings
that support both qcom,ipc and mboxes.
>
> > Since multiple SMSM hosts are supported, we need to be able to provide
> > the correct mailbox for each host. The old qcom,ipc-N properties map to
> > the mboxes property by index, starting at 0 since that's a valid SMSM
> > host also.
> >
> > The new example shows how an smsm node with just qcom,ipc-3 should be
> > specified with the mboxes property.
> >
> > Signed-off-by: Luca Weiss <[email protected]>
> > ---
> > .../devicetree/bindings/soc/qcom/qcom,smsm.yaml | 48 ++++++++++++++++++----
> > 1 file changed, 40 insertions(+), 8 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> > index db67cf043256..b12589171169 100644
> > --- a/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> > +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> > @@ -33,6 +33,13 @@ properties:
> > specifier of the column in the subscription matrix representing the local
> > processor.
> >
> > + mboxes:
> > + minItems: 1
> > + maxItems: 5
>
> Need to define what each entry is.
The entry is (description from qcom,ipc-N)
"the outgoing ipc bit used for signaling the N:th remote processor."
So you want me to add 5 times e.g.
- the IPC mailbox used for signaling the 0th remote processor
- the IPC mailbox used for signaling the 1st remote processor
etc? I don't really have any extra knowledge on smsm to be able to write
something better there..
Also what are your thoughts on this binding vs the alternative I wrote
in the cover letter? I'm not really happy about how the properties are
represented.
Regards
Luca
>
> > + description:
> > + Reference to the mailbox representing the outgoing doorbell in APCS for
> > + this client.
> > +
> > '#size-cells':
> > const: 0
> >
> > @@ -98,15 +105,18 @@ required:
> > - '#address-cells'
> > - '#size-cells'
> >
> > -anyOf:
> > +oneOf:
> > - required:
> > - - qcom,ipc-1
> > - - required:
> > - - qcom,ipc-2
> > - - required:
> > - - qcom,ipc-3
> > - - required:
> > - - qcom,ipc-4
> > + - mboxes
> > + - anyOf:
> > + - required:
> > + - qcom,ipc-1
> > + - required:
> > + - qcom,ipc-2
> > + - required:
> > + - qcom,ipc-3
> > + - required:
> > + - qcom,ipc-4
> >
> > additionalProperties: false
> >
> > @@ -136,3 +146,25 @@ examples:
> > #interrupt-cells = <2>;
> > };
> > };
> > + # Example using mboxes property
> > + - |
> > + #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +
> > + shared-memory {
> > + compatible = "qcom,smsm";
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > + mboxes = <0>, <0>, <0>, <&apcs 19>;
> > +
> > + apps@0 {
> > + reg = <0>;
> > + #qcom,smem-state-cells = <1>;
> > + };
> > +
> > + wcnss@7 {
> > + reg = <7>;
> > + interrupts = <GIC_SPI 144 IRQ_TYPE_EDGE_RISING>;
> > + interrupt-controller;
> > + #interrupt-cells = <2>;
> > + };
> > + };
> >
>
Hi Rob,
Any feedback on the below topic?
Regards
Luca
On Donnerstag, 25. April 2024 20:54:40 MESZ Luca Weiss wrote:
> On Donnerstag, 25. April 2024 18:17:15 MESZ Rob Herring wrote:
> > On Wed, Apr 24, 2024 at 07:21:51PM +0200, Luca Weiss wrote:
> > > The qcom,ipc-N properties are essentially providing a reference to a
> > > mailbox, so allow using the mboxes property to do the same in a more
> > > structured way.
> >
> > Can we mark qcom,ipc-N as deprecated then?
>
> Yes, that should be ok. Will also send a similar change to the other bindings
> that support both qcom,ipc and mboxes.
>
> >
> > > Since multiple SMSM hosts are supported, we need to be able to provide
> > > the correct mailbox for each host. The old qcom,ipc-N properties map to
> > > the mboxes property by index, starting at 0 since that's a valid SMSM
> > > host also.
> > >
> > > The new example shows how an smsm node with just qcom,ipc-3 should be
> > > specified with the mboxes property.
> > >
> > > Signed-off-by: Luca Weiss <[email protected]>
> > > ---
> > > .../devicetree/bindings/soc/qcom/qcom,smsm.yaml | 48 ++++++++++++++++++----
> > > 1 file changed, 40 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> > > index db67cf043256..b12589171169 100644
> > > --- a/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> > > +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> > > @@ -33,6 +33,13 @@ properties:
> > > specifier of the column in the subscription matrix representing the local
> > > processor.
> > >
> > > + mboxes:
> > > + minItems: 1
> > > + maxItems: 5
> >
> > Need to define what each entry is.
>
> The entry is (description from qcom,ipc-N)
>
> "the outgoing ipc bit used for signaling the N:th remote processor."
>
> So you want me to add 5 times e.g.
>
> - the IPC mailbox used for signaling the 0th remote processor
> - the IPC mailbox used for signaling the 1st remote processor
>
> etc? I don't really have any extra knowledge on smsm to be able to write
> something better there..
>
> Also what are your thoughts on this binding vs the alternative I wrote
> in the cover letter? I'm not really happy about how the properties are
> represented.
>
> Regards
> Luca
>
>
> >
> > > + description:
> > > + Reference to the mailbox representing the outgoing doorbell in APCS for
> > > + this client.
> > > +
> > > '#size-cells':
> > > const: 0
> > >
> > > @@ -98,15 +105,18 @@ required:
> > > - '#address-cells'
> > > - '#size-cells'
> > >
> > > -anyOf:
> > > +oneOf:
> > > - required:
> > > - - qcom,ipc-1
> > > - - required:
> > > - - qcom,ipc-2
> > > - - required:
> > > - - qcom,ipc-3
> > > - - required:
> > > - - qcom,ipc-4
> > > + - mboxes
> > > + - anyOf:
> > > + - required:
> > > + - qcom,ipc-1
> > > + - required:
> > > + - qcom,ipc-2
> > > + - required:
> > > + - qcom,ipc-3
> > > + - required:
> > > + - qcom,ipc-4
> > >
> > > additionalProperties: false
> > >
> > > @@ -136,3 +146,25 @@ examples:
> > > #interrupt-cells = <2>;
> > > };
> > > };
> > > + # Example using mboxes property
> > > + - |
> > > + #include <dt-bindings/interrupt-controller/arm-gic.h>
> > > +
> > > + shared-memory {
> > > + compatible = "qcom,smsm";
> > > + #address-cells = <1>;
> > > + #size-cells = <0>;
> > > + mboxes = <0>, <0>, <0>, <&apcs 19>;
> > > +
> > > + apps@0 {
> > > + reg = <0>;
> > > + #qcom,smem-state-cells = <1>;
> > > + };
> > > +
> > > + wcnss@7 {
> > > + reg = <7>;
> > > + interrupts = <GIC_SPI 144 IRQ_TYPE_EDGE_RISING>;
> > > + interrupt-controller;
> > > + #interrupt-cells = <2>;
> > > + };
> > > + };
> > >
> >
>
>
On 15/05/2024 17:06, Luca Weiss wrote:
> Hi Rob,
>
> Any feedback on the below topic?
Can be explained in description, like
mboxes:
description: Each entry corresponds to one remote processor
maxItems: 5
Best regards,
Krzysztof
On Montag, 20. Mai 2024 08:46:39 MESZ Krzysztof Kozlowski wrote:
> On 15/05/2024 17:06, Luca Weiss wrote:
> > Hi Rob,
> >
> > Any feedback on the below topic?
>
> Can be explained in description, like
> mboxes:
> description: Each entry corresponds to one remote processor
> maxItems: 5
Hi Krzysztof
Ack, sounds good.
Maybe also from you, any opinion between these two binding styles?
So first using index of mboxes for the numbering, where for the known
usages the first element (and sometimes the 3rd - ipc-2) are empty <>.
The second variant is using mbox-names to get the correct channel-mbox
mapping.
- qcom,ipc-1 = <&apcs 8 13>;
- qcom,ipc-2 = <&apcs 8 9>;
- qcom,ipc-3 = <&apcs 8 19>;
+ mboxes = <0>, <&apcs 13>, <&apcs 9>, <&apcs 19>;
vs.
- qcom,ipc-1 = <&apcs 8 13>;
- qcom,ipc-2 = <&apcs 8 9>;
- qcom,ipc-3 = <&apcs 8 19>;
+ mboxes = <&apcs 13>, <&apcs 9>, <&apcs 19>;
+ mbox-names = "ipc-1", "ipc-2", "ipc-3";
Regards
Luca
>
> Best regards,
> Krzysztof
>
>
On 20/05/2024 17:11, Luca Weiss wrote:
> Hi Krzysztof
>
> Ack, sounds good.
>
> Maybe also from you, any opinion between these two binding styles?
>
> So first using index of mboxes for the numbering, where for the known
> usages the first element (and sometimes the 3rd - ipc-2) are empty <>.
>
> The second variant is using mbox-names to get the correct channel-mbox
> mapping.
>
> - qcom,ipc-1 = <&apcs 8 13>;
> - qcom,ipc-2 = <&apcs 8 9>;
> - qcom,ipc-3 = <&apcs 8 19>;
> + mboxes = <0>, <&apcs 13>, <&apcs 9>, <&apcs 19>;
>
> vs.
>
> - qcom,ipc-1 = <&apcs 8 13>;
> - qcom,ipc-2 = <&apcs 8 9>;
> - qcom,ipc-3 = <&apcs 8 19>;
> + mboxes = <&apcs 13>, <&apcs 9>, <&apcs 19>;
> + mbox-names = "ipc-1", "ipc-2", "ipc-3";
Sorry, don't get, ipc-1 is the first mailbox, so why would there be <0>
in first case? Anyway, the question is if you need to know that some
mailbox is missing. But then it is weird to name them "ipc-1" etc.
Best regards,
Krzysztof
On Dienstag, 21. Mai 2024 10:58:07 MESZ Krzysztof Kozlowski wrote:
> On 20/05/2024 17:11, Luca Weiss wrote:
> > Hi Krzysztof
> >
> > Ack, sounds good.
> >
> > Maybe also from you, any opinion between these two binding styles?
> >
> > So first using index of mboxes for the numbering, where for the known
> > usages the first element (and sometimes the 3rd - ipc-2) are empty <>.
> >
> > The second variant is using mbox-names to get the correct channel-mbox
> > mapping.
> >
> > - qcom,ipc-1 = <&apcs 8 13>;
> > - qcom,ipc-2 = <&apcs 8 9>;
> > - qcom,ipc-3 = <&apcs 8 19>;
> > + mboxes = <0>, <&apcs 13>, <&apcs 9>, <&apcs 19>;
> >
> > vs.
> >
> > - qcom,ipc-1 = <&apcs 8 13>;
> > - qcom,ipc-2 = <&apcs 8 9>;
> > - qcom,ipc-3 = <&apcs 8 19>;
> > + mboxes = <&apcs 13>, <&apcs 9>, <&apcs 19>;
> > + mbox-names = "ipc-1", "ipc-2", "ipc-3";
>
> Sorry, don't get, ipc-1 is the first mailbox, so why would there be <0>
> in first case?
Actually not, ipc-0 would be permissible by the driver, used for the 0th host
e.g. from:
/* Iterate over all hosts to check whom wants a kick */
for (host = 0; host < smsm->num_hosts; host++) {
hostp = &smsm->hosts[host];
Even though no mailbox is specified in any upstream dts for this 0th host I
didn't want the bindings to restrict that, that's why in the first example
there's an empty element (<0>) for the 0th smsm host
> Anyway, the question is if you need to know that some
> mailbox is missing. But then it is weird to name them "ipc-1" etc.
In either case we'd just query the mbox (either by name or index) and then
see if it's there? Not quite sure I understand the sentence..
Pretty sure either binding would work the same way.
Regards
Luca
>
> Best regards,
> Krzysztof
>
>
On 21/05/2024 22:35, Luca Weiss wrote:
> On Dienstag, 21. Mai 2024 10:58:07 MESZ Krzysztof Kozlowski wrote:
>> On 20/05/2024 17:11, Luca Weiss wrote:
>>> Hi Krzysztof
>>>
>>> Ack, sounds good.
>>>
>>> Maybe also from you, any opinion between these two binding styles?
>>>
>>> So first using index of mboxes for the numbering, where for the known
>>> usages the first element (and sometimes the 3rd - ipc-2) are empty <>.
>>>
>>> The second variant is using mbox-names to get the correct channel-mbox
>>> mapping.
>>>
>>> - qcom,ipc-1 = <&apcs 8 13>;
>>> - qcom,ipc-2 = <&apcs 8 9>;
>>> - qcom,ipc-3 = <&apcs 8 19>;
>>> + mboxes = <0>, <&apcs 13>, <&apcs 9>, <&apcs 19>;
>>>
>>> vs.
>>>
>>> - qcom,ipc-1 = <&apcs 8 13>;
>>> - qcom,ipc-2 = <&apcs 8 9>;
>>> - qcom,ipc-3 = <&apcs 8 19>;
>>> + mboxes = <&apcs 13>, <&apcs 9>, <&apcs 19>;
>>> + mbox-names = "ipc-1", "ipc-2", "ipc-3";
>>
>> Sorry, don't get, ipc-1 is the first mailbox, so why would there be <0>
>> in first case?
>
> Actually not, ipc-0 would be permissible by the driver, used for the 0th host
>
> e.g. from:
>
> /* Iterate over all hosts to check whom wants a kick */
> for (host = 0; host < smsm->num_hosts; host++) {
> hostp = &smsm->hosts[host];
>
> Even though no mailbox is specified in any upstream dts for this 0th host I
> didn't want the bindings to restrict that, that's why in the first example
> there's an empty element (<0>) for the 0th smsm host
>
>> Anyway, the question is if you need to know that some
>> mailbox is missing. But then it is weird to name them "ipc-1" etc.
>
> In either case we'd just query the mbox (either by name or index) and then
> see if it's there? Not quite sure I understand the sentence..
> Pretty sure either binding would work the same way.
The question is: does the driver care only about having some mailboxes
or the driver cares about each specific mailbox? IOW, is skipping ipc-0
important for the driver?
Best regards,
Krzysztof
On Mittwoch, 22. Mai 2024 08:49:43 MESZ Krzysztof Kozlowski wrote:
> On 21/05/2024 22:35, Luca Weiss wrote:
> > On Dienstag, 21. Mai 2024 10:58:07 MESZ Krzysztof Kozlowski wrote:
> >> On 20/05/2024 17:11, Luca Weiss wrote:
> >>> Hi Krzysztof
> >>>
> >>> Ack, sounds good.
> >>>
> >>> Maybe also from you, any opinion between these two binding styles?
> >>>
> >>> So first using index of mboxes for the numbering, where for the known
> >>> usages the first element (and sometimes the 3rd - ipc-2) are empty <>.
> >>>
> >>> The second variant is using mbox-names to get the correct channel-mbox
> >>> mapping.
> >>>
> >>> - qcom,ipc-1 = <&apcs 8 13>;
> >>> - qcom,ipc-2 = <&apcs 8 9>;
> >>> - qcom,ipc-3 = <&apcs 8 19>;
> >>> + mboxes = <0>, <&apcs 13>, <&apcs 9>, <&apcs 19>;
> >>>
> >>> vs.
> >>>
> >>> - qcom,ipc-1 = <&apcs 8 13>;
> >>> - qcom,ipc-2 = <&apcs 8 9>;
> >>> - qcom,ipc-3 = <&apcs 8 19>;
> >>> + mboxes = <&apcs 13>, <&apcs 9>, <&apcs 19>;
> >>> + mbox-names = "ipc-1", "ipc-2", "ipc-3";
> >>
> >> Sorry, don't get, ipc-1 is the first mailbox, so why would there be <0>
> >> in first case?
> >
> > Actually not, ipc-0 would be permissible by the driver, used for the 0th host
> >
> > e.g. from:
> >
> > /* Iterate over all hosts to check whom wants a kick */
> > for (host = 0; host < smsm->num_hosts; host++) {
> > hostp = &smsm->hosts[host];
> >
> > Even though no mailbox is specified in any upstream dts for this 0th host I
> > didn't want the bindings to restrict that, that's why in the first example
> > there's an empty element (<0>) for the 0th smsm host
> >
> >> Anyway, the question is if you need to know that some
> >> mailbox is missing. But then it is weird to name them "ipc-1" etc.
> >
> > In either case we'd just query the mbox (either by name or index) and then
> > see if it's there? Not quite sure I understand the sentence..
> > Pretty sure either binding would work the same way.
>
> The question is: does the driver care only about having some mailboxes
> or the driver cares about each specific mailbox? IOW, is skipping ipc-0
> important for the driver?
There's nothing special from driver side about any mailbox. Some SoCs have
a mailbox for e.g. hosts 1&2&3, some have only 1&3, and apq8064 even has
1&2&3&4.
And if the driver doesn't find a mailbox for a host, it just ignores it
but then of course it can't 'ring' the mailbox for that host when necessary.
Not sure how much more I can add here, to be fair I barely understand what
this driver is doing myself apart from the obvious.
Regards
Luca
>
>
> Best regards,
> Krzysztof
>
>
On 22/05/2024 19:34, Luca Weiss wrote:
> On Mittwoch, 22. Mai 2024 08:49:43 MESZ Krzysztof Kozlowski wrote:
>> On 21/05/2024 22:35, Luca Weiss wrote:
>>> On Dienstag, 21. Mai 2024 10:58:07 MESZ Krzysztof Kozlowski wrote:
>>>> On 20/05/2024 17:11, Luca Weiss wrote:
>>>>> Hi Krzysztof
>>>>>
>>>>> Ack, sounds good.
>>>>>
>>>>> Maybe also from you, any opinion between these two binding styles?
>>>>>
>>>>> So first using index of mboxes for the numbering, where for the known
>>>>> usages the first element (and sometimes the 3rd - ipc-2) are empty <>.
>>>>>
>>>>> The second variant is using mbox-names to get the correct channel-mbox
>>>>> mapping.
>>>>>
>>>>> - qcom,ipc-1 = <&apcs 8 13>;
>>>>> - qcom,ipc-2 = <&apcs 8 9>;
>>>>> - qcom,ipc-3 = <&apcs 8 19>;
>>>>> + mboxes = <0>, <&apcs 13>, <&apcs 9>, <&apcs 19>;
>>>>>
>>>>> vs.
>>>>>
>>>>> - qcom,ipc-1 = <&apcs 8 13>;
>>>>> - qcom,ipc-2 = <&apcs 8 9>;
>>>>> - qcom,ipc-3 = <&apcs 8 19>;
>>>>> + mboxes = <&apcs 13>, <&apcs 9>, <&apcs 19>;
>>>>> + mbox-names = "ipc-1", "ipc-2", "ipc-3";
>>>>
>>>> Sorry, don't get, ipc-1 is the first mailbox, so why would there be <0>
>>>> in first case?
>>>
>>> Actually not, ipc-0 would be permissible by the driver, used for the 0th host
>>>
>>> e.g. from:
>>>
>>> /* Iterate over all hosts to check whom wants a kick */
>>> for (host = 0; host < smsm->num_hosts; host++) {
>>> hostp = &smsm->hosts[host];
>>>
>>> Even though no mailbox is specified in any upstream dts for this 0th host I
>>> didn't want the bindings to restrict that, that's why in the first example
>>> there's an empty element (<0>) for the 0th smsm host
>>>
>>>> Anyway, the question is if you need to know that some
>>>> mailbox is missing. But then it is weird to name them "ipc-1" etc.
>>>
>>> In either case we'd just query the mbox (either by name or index) and then
>>> see if it's there? Not quite sure I understand the sentence..
>>> Pretty sure either binding would work the same way.
>>
>> The question is: does the driver care only about having some mailboxes
>> or the driver cares about each specific mailbox? IOW, is skipping ipc-0
>> important for the driver?
>
> There's nothing special from driver side about any mailbox. Some SoCs have
> a mailbox for e.g. hosts 1&2&3, some have only 1&3, and apq8064 even has
> 1&2&3&4.
>
> And if the driver doesn't find a mailbox for a host, it just ignores it
> but then of course it can't 'ring' the mailbox for that host when necessary.
>
> Not sure how much more I can add here, to be fair I barely understand what
> this driver is doing myself apart from the obvious.
From what you said, it looks like it is enough to just list mailboxes,
e.g. for ipc-1, ipc-2 and ipc-4 (so no ipc-0 and ipc-3):
mboxes = <&apcs 13>, <&apcs 9>, <&apcs 19>;
Best regards,
Krzysztof
On Donnerstag, 23. Mai 2024 08:02:13 MESZ Krzysztof Kozlowski wrote:
> On 22/05/2024 19:34, Luca Weiss wrote:
> > On Mittwoch, 22. Mai 2024 08:49:43 MESZ Krzysztof Kozlowski wrote:
> >> On 21/05/2024 22:35, Luca Weiss wrote:
> >>> On Dienstag, 21. Mai 2024 10:58:07 MESZ Krzysztof Kozlowski wrote:
> >>>> On 20/05/2024 17:11, Luca Weiss wrote:
> >>>>> Hi Krzysztof
> >>>>>
> >>>>> Ack, sounds good.
> >>>>>
> >>>>> Maybe also from you, any opinion between these two binding styles?
> >>>>>
> >>>>> So first using index of mboxes for the numbering, where for the known
> >>>>> usages the first element (and sometimes the 3rd - ipc-2) are empty <>.
> >>>>>
> >>>>> The second variant is using mbox-names to get the correct channel-mbox
> >>>>> mapping.
> >>>>>
> >>>>> - qcom,ipc-1 = <&apcs 8 13>;
> >>>>> - qcom,ipc-2 = <&apcs 8 9>;
> >>>>> - qcom,ipc-3 = <&apcs 8 19>;
> >>>>> + mboxes = <0>, <&apcs 13>, <&apcs 9>, <&apcs 19>;
> >>>>>
> >>>>> vs.
> >>>>>
> >>>>> - qcom,ipc-1 = <&apcs 8 13>;
> >>>>> - qcom,ipc-2 = <&apcs 8 9>;
> >>>>> - qcom,ipc-3 = <&apcs 8 19>;
> >>>>> + mboxes = <&apcs 13>, <&apcs 9>, <&apcs 19>;
> >>>>> + mbox-names = "ipc-1", "ipc-2", "ipc-3";
> >>>>
> >>>> Sorry, don't get, ipc-1 is the first mailbox, so why would there be <0>
> >>>> in first case?
> >>>
> >>> Actually not, ipc-0 would be permissible by the driver, used for the 0th host
> >>>
> >>> e.g. from:
> >>>
> >>> /* Iterate over all hosts to check whom wants a kick */
> >>> for (host = 0; host < smsm->num_hosts; host++) {
> >>> hostp = &smsm->hosts[host];
> >>>
> >>> Even though no mailbox is specified in any upstream dts for this 0th host I
> >>> didn't want the bindings to restrict that, that's why in the first example
> >>> there's an empty element (<0>) for the 0th smsm host
> >>>
> >>>> Anyway, the question is if you need to know that some
> >>>> mailbox is missing. But then it is weird to name them "ipc-1" etc.
> >>>
> >>> In either case we'd just query the mbox (either by name or index) and then
> >>> see if it's there? Not quite sure I understand the sentence..
> >>> Pretty sure either binding would work the same way.
> >>
> >> The question is: does the driver care only about having some mailboxes
> >> or the driver cares about each specific mailbox? IOW, is skipping ipc-0
> >> important for the driver?
> >
> > There's nothing special from driver side about any mailbox. Some SoCs have
> > a mailbox for e.g. hosts 1&2&3, some have only 1&3, and apq8064 even has
> > 1&2&3&4.
> >
> > And if the driver doesn't find a mailbox for a host, it just ignores it
> > but then of course it can't 'ring' the mailbox for that host when necessary.
> >
> > Not sure how much more I can add here, to be fair I barely understand what
> > this driver is doing myself apart from the obvious.
>
> From what you said, it looks like it is enough to just list mailboxes,
> e.g. for ipc-1, ipc-2 and ipc-4 (so no ipc-0 and ipc-3):
No, for sure we need also the possibility to list ipc-3.
And my point is that I'm not sure if any platform will ever need ipc-0, but
the code to use that if it ever exists is there - the driver always
tries getting an mbox (currently just syscon of course) for every host
from 0 to n.
These are the current (non-mbox-API) mboxes provided to smsm:
$ git grep qcom,ipc- arch/
arch/arm/boot/dts/qcom/qcom-apq8064.dtsi: qcom,ipc-1 = <&l2cc 8 4>;
arch/arm/boot/dts/qcom/qcom-apq8064.dtsi: qcom,ipc-2 = <&l2cc 8 14>;
arch/arm/boot/dts/qcom/qcom-apq8064.dtsi: qcom,ipc-3 = <&l2cc 8 23>;
arch/arm/boot/dts/qcom/qcom-apq8064.dtsi: qcom,ipc-4 = <&sps_sic_non_secure 0x4094 0>;
arch/arm/boot/dts/qcom/qcom-msm8974.dtsi: qcom,ipc-1 = <&apcs 8 13>;
arch/arm/boot/dts/qcom/qcom-msm8974.dtsi: qcom,ipc-2 = <&apcs 8 9>;
arch/arm/boot/dts/qcom/qcom-msm8974.dtsi: qcom,ipc-3 = <&apcs 8 19>;
arch/arm64/boot/dts/qcom/msm8916.dtsi: qcom,ipc-1 = <&apcs 8 13>;
arch/arm64/boot/dts/qcom/msm8916.dtsi: qcom,ipc-3 = <&apcs 8 19>;
arch/arm64/boot/dts/qcom/msm8939.dtsi: qcom,ipc-1 = <&apcs1_mbox 8 13>;
arch/arm64/boot/dts/qcom/msm8939.dtsi: qcom,ipc-3 = <&apcs1_mbox 8 19>;
arch/arm64/boot/dts/qcom/msm8953.dtsi: qcom,ipc-1 = <&apcs 8 13>;
arch/arm64/boot/dts/qcom/msm8953.dtsi: qcom,ipc-3 = <&apcs 8 19>;
arch/arm64/boot/dts/qcom/msm8976.dtsi: qcom,ipc-1 = <&apcs 8 13>;
arch/arm64/boot/dts/qcom/msm8976.dtsi: qcom,ipc-2 = <&apcs 8 9>;
arch/arm64/boot/dts/qcom/msm8976.dtsi: qcom,ipc-3 = <&apcs 8 19>;
>
> mboxes = <&apcs 13>, <&apcs 9>, <&apcs 19>;
>
> Best regards,
> Krzysztof
>
>