* [PATCH v4 0/2] mailbox: Add Broadcom STB mailbox driver for SCMI
@ 2020-10-29 19:59 Jim Quinlan
2020-10-29 19:59 ` [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver Jim Quinlan
0 siblings, 1 reply; 9+ messages in thread
From: Jim Quinlan @ 2020-10-29 19:59 UTC (permalink / raw)
To: sudeep.holla, bcm-kernel-feedback-list, james.quinlan
Cc: open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE, open list
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Patchset Summary:
Adds a simple mailbox driver for the use of the ARM SCMI drivers.
v4:
Commit "mailbox: Add Broadcom STB mailbox driver"
-- Fixed indentation on Kconfig file (again, RandyD).
-- Removed superfluous #ifdefs for ARM/ARM64 (RandyD).
-- Fixed Copyright year on source file (RandyD).
v3:
Commit "mailbox: Add Broadcom STB mailbox driver"
-- Fixed indentation on Kconfig file (RandyD).
v2:
Commit "mailbox: Add Broadcom STB mailbox driver"
-- Remove the Kconfig dependency on SMP (Florian)
Commit "mailbox: Add Broadcom STB mailbox driver"
-- Drop label,unit address; changed title,description (RobH)
v1:
-- Original submission.
Jim Quinlan (2):
dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver
mailbox: Add Broadcom STB mailbox driver
.../bindings/mailbox/brcm,brcmstb-mbox.yaml | 39 ++++
drivers/mailbox/Kconfig | 12 ++
drivers/mailbox/Makefile | 2 +
drivers/mailbox/brcmstb-mailbox.c | 167 ++++++++++++++++++
4 files changed, 220 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml
create mode 100644 drivers/mailbox/brcmstb-mailbox.c
--
2.17.1
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^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver
2020-10-29 19:59 [PATCH v4 0/2] mailbox: Add Broadcom STB mailbox driver for SCMI Jim Quinlan
@ 2020-10-29 19:59 ` Jim Quinlan
2020-11-04 21:50 ` Rob Herring
0 siblings, 1 reply; 9+ messages in thread
From: Jim Quinlan @ 2020-10-29 19:59 UTC (permalink / raw)
To: sudeep.holla, bcm-kernel-feedback-list, james.quinlan
Cc: Rob Herring, Florian Fainelli,
open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE, open list
[-- Attachment #1: Type: text/plain, Size: 1506 bytes --]
Bindings are added. Only one interrupt is needed because
we do not yet employ the SCMI p2a channel.
Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
---
.../bindings/mailbox/brcm,brcmstb-mbox.yaml | 39 +++++++++++++++++++
1 file changed, 39 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml
diff --git a/Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml b/Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml
new file mode 100644
index 000000000000..797c0cc609a3
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml
@@ -0,0 +1,39 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+$id: http://devicetree.org/schemas/mailbox/brcm,brcmstb-mbox.yaml#
+
+title: Broadcom STB mailbox driver bindings
+
+maintainers:
+ - Jim Quinlan <james.quinlan@broadcom.com>
+
+properties:
+ compatible:
+ enum:
+ - brcm,brcmstb-mbox
+
+ interrupts:
+ items:
+ - description: a2p return interrupt, indicates SCMI msg completion.
+
+ "#mbox-cells":
+ const: 1
+
+required:
+ - compatible
+ - interrupts
+ - "#mbox-cells"
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ mailbox {
+ compatible = "brcm,brcmstb-mailbox";
+ #mbox-cells = <1>;
+ interrupts = <GIC_SPI 0xc6 IRQ_TYPE_LEVEL_HIGH>;
+ };
+...
--
2.17.1
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^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver
2020-10-29 19:59 ` [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver Jim Quinlan
@ 2020-11-04 21:50 ` Rob Herring
2020-11-04 22:03 ` Jim Quinlan
0 siblings, 1 reply; 9+ messages in thread
From: Rob Herring @ 2020-11-04 21:50 UTC (permalink / raw)
To: Jim Quinlan
Cc: sudeep.holla, bcm-kernel-feedback-list, Florian Fainelli,
open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE, open list
On Thu, Oct 29, 2020 at 03:59:06PM -0400, Jim Quinlan wrote:
> Bindings are added. Only one interrupt is needed because
> we do not yet employ the SCMI p2a channel.
I still don't understand what this is. To repeat from v1: I thought SCMI
was a mailbox consumer, not provider?
>
> Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> ---
> .../bindings/mailbox/brcm,brcmstb-mbox.yaml | 39 +++++++++++++++++++
> 1 file changed, 39 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml
>
> diff --git a/Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml b/Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml
> new file mode 100644
> index 000000000000..797c0cc609a3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml
> @@ -0,0 +1,39 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +$id: http://devicetree.org/schemas/mailbox/brcm,brcmstb-mbox.yaml#
> +
> +title: Broadcom STB mailbox driver bindings
> +
> +maintainers:
> + - Jim Quinlan <james.quinlan@broadcom.com>
> +
> +properties:
> + compatible:
> + enum:
> + - brcm,brcmstb-mbox
> +
> + interrupts:
> + items:
> + - description: a2p return interrupt, indicates SCMI msg completion.
> +
> + "#mbox-cells":
> + const: 1
> +
> +required:
> + - compatible
> + - interrupts
> + - "#mbox-cells"
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + mailbox {
> + compatible = "brcm,brcmstb-mailbox";
> + #mbox-cells = <1>;
> + interrupts = <GIC_SPI 0xc6 IRQ_TYPE_LEVEL_HIGH>;
> + };
> +...
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver
2020-11-04 21:50 ` Rob Herring
@ 2020-11-04 22:03 ` Jim Quinlan
2020-11-05 15:13 ` Rob Herring
0 siblings, 1 reply; 9+ messages in thread
From: Jim Quinlan @ 2020-11-04 22:03 UTC (permalink / raw)
To: Rob Herring
Cc: Sudeep Holla, maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE,
Florian Fainelli,
open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE, open list
[-- Attachment #1: Type: text/plain, Size: 2521 bytes --]
On Wed, Nov 4, 2020 at 4:50 PM Rob Herring <robh@kernel.org> wrote:
>
> On Thu, Oct 29, 2020 at 03:59:06PM -0400, Jim Quinlan wrote:
> > Bindings are added. Only one interrupt is needed because
> > we do not yet employ the SCMI p2a channel.
>
> I still don't understand what this is. To repeat from v1: I thought SCMI
> was a mailbox consumer, not provider?
Hi Rob,
I'm not sure where I am implying that SCMI is a mailbox provider?
Should I not mention "SCMI" in the subject line?
This is just a mailbox driver, "consumed" by SCMI. Our SCMI DT node
looks like this:
brcm_scmi_mailbox: brcm_scmi_mailbox@0 {
#mbox-cells = <1>;
compatible = "brcm,brcmstb-mbox";
};
brcm_scmi@0 {
compatible = "arm,scmi";
mboxes = <&brcm_scmi_mailbox 0>;;
mbox-names = "tx";
shmem = <&NWMBOX>;
/* ... */
};
Please advise,
Jim Quinlan
Broadcom STB
>
> >
> > Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> > ---
> > .../bindings/mailbox/brcm,brcmstb-mbox.yaml | 39 +++++++++++++++++++
> > 1 file changed, 39 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml b/Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml
> > new file mode 100644
> > index 000000000000..797c0cc609a3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mailbox/brcm,brcmstb-mbox.yaml
> > @@ -0,0 +1,39 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> > +$id: http://devicetree.org/schemas/mailbox/brcm,brcmstb-mbox.yaml#
> > +
> > +title: Broadcom STB mailbox driver bindings
> > +
> > +maintainers:
> > + - Jim Quinlan <james.quinlan@broadcom.com>
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - brcm,brcmstb-mbox
> > +
> > + interrupts:
> > + items:
> > + - description: a2p return interrupt, indicates SCMI msg completion.
> > +
> > + "#mbox-cells":
> > + const: 1
> > +
> > +required:
> > + - compatible
> > + - interrupts
> > + - "#mbox-cells"
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > + - |
> > + #include <dt-bindings/interrupt-controller/arm-gic.h>
> > + mailbox {
> > + compatible = "brcm,brcmstb-mailbox";
> > + #mbox-cells = <1>;
> > + interrupts = <GIC_SPI 0xc6 IRQ_TYPE_LEVEL_HIGH>;
> > + };
> > +...
> > --
> > 2.17.1
> >
>
>
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver
2020-11-04 22:03 ` Jim Quinlan
@ 2020-11-05 15:13 ` Rob Herring
2020-11-05 15:28 ` Jim Quinlan
0 siblings, 1 reply; 9+ messages in thread
From: Rob Herring @ 2020-11-05 15:13 UTC (permalink / raw)
To: Jim Quinlan
Cc: Sudeep Holla, maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE,
Florian Fainelli,
open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE, open list
On Wed, Nov 4, 2020 at 4:04 PM Jim Quinlan <james.quinlan@broadcom.com> wrote:
>
> On Wed, Nov 4, 2020 at 4:50 PM Rob Herring <robh@kernel.org> wrote:
> >
> > On Thu, Oct 29, 2020 at 03:59:06PM -0400, Jim Quinlan wrote:
> > > Bindings are added. Only one interrupt is needed because
> > > we do not yet employ the SCMI p2a channel.
> >
> > I still don't understand what this is. To repeat from v1: I thought SCMI
> > was a mailbox consumer, not provider?
>
> Hi Rob,
>
> I'm not sure where I am implying that SCMI is a mailbox provider?
> Should I not mention "SCMI" in the subject line?
>
> This is just a mailbox driver, "consumed" by SCMI. Our SCMI DT node
> looks like this:
>
> brcm_scmi_mailbox: brcm_scmi_mailbox@0 {
> #mbox-cells = <1>;
> compatible = "brcm,brcmstb-mbox";
> };
>
> brcm_scmi@0 {
> compatible = "arm,scmi";
> mboxes = <&brcm_scmi_mailbox 0>;;
> mbox-names = "tx";
> shmem = <&NWMBOX>;
> /* ... */
> };
Okay, that makes more sense. Though it seems like this is just adding
a pointless level of indirection to turn an interrupt into a mailbox.
There's nothing more to 'the mailbox' is there? So why not either
allow SCMI to have an interrupt directly or have a generic irq mailbox
driver?
Rob
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver
2020-11-05 15:13 ` Rob Herring
@ 2020-11-05 15:28 ` Jim Quinlan
2020-11-05 18:27 ` Sudeep Holla
0 siblings, 1 reply; 9+ messages in thread
From: Jim Quinlan @ 2020-11-05 15:28 UTC (permalink / raw)
To: Rob Herring
Cc: Sudeep Holla, maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE,
Florian Fainelli,
open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE, open list
[-- Attachment #1: Type: text/plain, Size: 1849 bytes --]
On Thu, Nov 5, 2020 at 10:13 AM Rob Herring <robh@kernel.org> wrote:
>
> On Wed, Nov 4, 2020 at 4:04 PM Jim Quinlan <james.quinlan@broadcom.com> wrote:
> >
> > On Wed, Nov 4, 2020 at 4:50 PM Rob Herring <robh@kernel.org> wrote:
> > >
> > > On Thu, Oct 29, 2020 at 03:59:06PM -0400, Jim Quinlan wrote:
> > > > Bindings are added. Only one interrupt is needed because
> > > > we do not yet employ the SCMI p2a channel.
> > >
> > > I still don't understand what this is. To repeat from v1: I thought SCMI
> > > was a mailbox consumer, not provider?
> >
> > Hi Rob,
> >
> > I'm not sure where I am implying that SCMI is a mailbox provider?
> > Should I not mention "SCMI" in the subject line?
> >
> > This is just a mailbox driver, "consumed" by SCMI. Our SCMI DT node
> > looks like this:
> >
> > brcm_scmi_mailbox: brcm_scmi_mailbox@0 {
> > #mbox-cells = <1>;
> > compatible = "brcm,brcmstb-mbox";
> > };
> >
> > brcm_scmi@0 {
> > compatible = "arm,scmi";
> > mboxes = <&brcm_scmi_mailbox 0>;;
> > mbox-names = "tx";
> > shmem = <&NWMBOX>;
> > /* ... */
> > };
>
> Okay, that makes more sense. Though it seems like this is just adding
> a pointless level of indirection to turn an interrupt into a mailbox.
> There's nothing more to 'the mailbox' is there?
Correct. Although you can see that it uses both interrupts and SMC
calls to get the job done.
> So why not either
> allow SCMI to have an interrupt directly
Not sure here -- perhaps the SCMI folks have an answer?
> or have a generic irq mailbox
> driver?
The SCMI implementation doesn't offer a generic irq mailbox driver
AFAICT. The SCMI folks recently provided an "smc transport" driver
in "drivers/firmware/arm_scmi/smc.c" -- it is close to what we need
but is missing interrupts.
Regards,
Jim Quinlan
Broadcom STB
>
> Rob
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver
2020-11-05 15:28 ` Jim Quinlan
@ 2020-11-05 18:27 ` Sudeep Holla
2020-11-05 18:57 ` Jim Quinlan
0 siblings, 1 reply; 9+ messages in thread
From: Sudeep Holla @ 2020-11-05 18:27 UTC (permalink / raw)
To: Jim Quinlan
Cc: Rob Herring, maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE,
Florian Fainelli, Sudeep Holla,
open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE, open list
On Thu, Nov 05, 2020 at 10:28:25AM -0500, Jim Quinlan wrote:
> On Thu, Nov 5, 2020 at 10:13 AM Rob Herring <robh@kernel.org> wrote:
> >
> > On Wed, Nov 4, 2020 at 4:04 PM Jim Quinlan <james.quinlan@broadcom.com> wrote:
> > >
> > > On Wed, Nov 4, 2020 at 4:50 PM Rob Herring <robh@kernel.org> wrote:
> > > >
> > > > On Thu, Oct 29, 2020 at 03:59:06PM -0400, Jim Quinlan wrote:
> > > > > Bindings are added. Only one interrupt is needed because
> > > > > we do not yet employ the SCMI p2a channel.
> > > >
> > > > I still don't understand what this is. To repeat from v1: I thought SCMI
> > > > was a mailbox consumer, not provider?
> > >
> > > Hi Rob,
> > >
> > > I'm not sure where I am implying that SCMI is a mailbox provider?
> > > Should I not mention "SCMI" in the subject line?
> > >
> > > This is just a mailbox driver, "consumed" by SCMI. Our SCMI DT node
> > > looks like this:
> > >
> > > brcm_scmi_mailbox: brcm_scmi_mailbox@0 {
> > > #mbox-cells = <1>;
> > > compatible = "brcm,brcmstb-mbox";
> > > };
> > >
> > > brcm_scmi@0 {
> > > compatible = "arm,scmi";
> > > mboxes = <&brcm_scmi_mailbox 0>;;
> > > mbox-names = "tx";
> > > shmem = <&NWMBOX>;
> > > /* ... */
> > > };
> >
> > Okay, that makes more sense. Though it seems like this is just adding
> > a pointless level of indirection to turn an interrupt into a mailbox.
> > There's nothing more to 'the mailbox' is there?
>
> Correct. Although you can see that it uses both interrupts and SMC
> calls to get the job done.
>
I was against having 2 separate solutions and would have raised my concern
again. As I mentioned earlier, either extend what we have or move the
existing SMC solution into this mailbox driver. Having 2 different solution
for this just because you have extra interrupt to deal with is definite
NACK from me as I had previously mentioned.
> > So why not either
> > allow SCMI to have an interrupt directly
> Not sure here -- perhaps the SCMI folks have an answer?
>
I did ask why can't you extend the existing SCMI/SMC binding to add this
as optional feature ?
> > or have a generic irq mailbox driver?
Fine with this too.
> The SCMI implementation doesn't offer a generic irq mailbox driver
> AFAICT. The SCMI folks recently provided an "smc transport" driver
> in "drivers/firmware/arm_scmi/smc.c" -- it is close to what we need
> but is missing interrupts.
IIRC, you were using SGIs and it can't be represented and use today as
is ? Am I missing something or anything has changed ?
--
Regards,
Sudeep
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver
2020-11-05 18:27 ` Sudeep Holla
@ 2020-11-05 18:57 ` Jim Quinlan
2020-11-05 19:05 ` Sudeep Holla
0 siblings, 1 reply; 9+ messages in thread
From: Jim Quinlan @ 2020-11-05 18:57 UTC (permalink / raw)
To: Sudeep Holla
Cc: Rob Herring, maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE,
Florian Fainelli,
open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE, open list
[-- Attachment #1: Type: text/plain, Size: 3161 bytes --]
On Thu, Nov 5, 2020 at 1:27 PM Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> On Thu, Nov 05, 2020 at 10:28:25AM -0500, Jim Quinlan wrote:
> > On Thu, Nov 5, 2020 at 10:13 AM Rob Herring <robh@kernel.org> wrote:
> > >
> > > On Wed, Nov 4, 2020 at 4:04 PM Jim Quinlan <james.quinlan@broadcom.com> wrote:
> > > >
> > > > On Wed, Nov 4, 2020 at 4:50 PM Rob Herring <robh@kernel.org> wrote:
> > > > >
> > > > > On Thu, Oct 29, 2020 at 03:59:06PM -0400, Jim Quinlan wrote:
> > > > > > Bindings are added. Only one interrupt is needed because
> > > > > > we do not yet employ the SCMI p2a channel.
> > > > >
> > > > > I still don't understand what this is. To repeat from v1: I thought SCMI
> > > > > was a mailbox consumer, not provider?
> > > >
> > > > Hi Rob,
> > > >
> > > > I'm not sure where I am implying that SCMI is a mailbox provider?
> > > > Should I not mention "SCMI" in the subject line?
> > > >
> > > > This is just a mailbox driver, "consumed" by SCMI. Our SCMI DT node
> > > > looks like this:
> > > >
> > > > brcm_scmi_mailbox: brcm_scmi_mailbox@0 {
> > > > #mbox-cells = <1>;
> > > > compatible = "brcm,brcmstb-mbox";
> > > > };
> > > >
> > > > brcm_scmi@0 {
> > > > compatible = "arm,scmi";
> > > > mboxes = <&brcm_scmi_mailbox 0>;;
> > > > mbox-names = "tx";
> > > > shmem = <&NWMBOX>;
> > > > /* ... */
> > > > };
> > >
> > > Okay, that makes more sense. Though it seems like this is just adding
> > > a pointless level of indirection to turn an interrupt into a mailbox.
> > > There's nothing more to 'the mailbox' is there?
> >
> > Correct. Although you can see that it uses both interrupts and SMC
> > calls to get the job done.
> >
>
> I was against having 2 separate solutions and would have raised my concern
> again. As I mentioned earlier, either extend what we have or move the
> existing SMC solution into this mailbox driver. Having 2 different solution
> for this just because you have extra interrupt to deal with is definite
> NACK from me as I had previously mentioned.
>
> > > So why not either
> > > allow SCMI to have an interrupt directly
> > Not sure here -- perhaps the SCMI folks have an answer?
> >
>
> I did ask why can't you extend the existing SCMI/SMC binding to add this
> as optional feature ?
Hi Sudeep,
Looking at the email you said, "In that case any reason why you can't
reuse the existing smc transport for SCMI." , and I replied with the
reason. I did not interpret your statement above as what you are
clearly saying now: "either extend what we have or move the existing
SMC solution into this mailbox driver. "
Fair enough, I will look into this.
Regards,
Jim
>
> > > or have a generic irq mailbox driver?
>
> Fine with this too.
>
> > The SCMI implementation doesn't offer a generic irq mailbox driver
> > AFAICT. The SCMI folks recently provided an "smc transport" driver
> > in "drivers/firmware/arm_scmi/smc.c" -- it is close to what we need
> > but is missing interrupts.
>
> IIRC, you were using SGIs and it can't be represented and use today as
> is ? Am I missing something or anything has changed ?
>
> --
> Regards,
> Sudeep
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver
2020-11-05 18:57 ` Jim Quinlan
@ 2020-11-05 19:05 ` Sudeep Holla
0 siblings, 0 replies; 9+ messages in thread
From: Sudeep Holla @ 2020-11-05 19:05 UTC (permalink / raw)
To: Jim Quinlan
Cc: Rob Herring, maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE,
Sudeep Holla, Florian Fainelli,
open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE, open list
On Thu, Nov 05, 2020 at 01:57:07PM -0500, Jim Quinlan wrote:
> On Thu, Nov 5, 2020 at 1:27 PM Sudeep Holla <sudeep.holla@arm.com> wrote:
> >
> > On Thu, Nov 05, 2020 at 10:28:25AM -0500, Jim Quinlan wrote:
> > > On Thu, Nov 5, 2020 at 10:13 AM Rob Herring <robh@kernel.org> wrote:
> > > >
> > > > On Wed, Nov 4, 2020 at 4:04 PM Jim Quinlan <james.quinlan@broadcom.com> wrote:
> > > > >
> > > > > On Wed, Nov 4, 2020 at 4:50 PM Rob Herring <robh@kernel.org> wrote:
> > > > > >
> > > > > > On Thu, Oct 29, 2020 at 03:59:06PM -0400, Jim Quinlan wrote:
> > > > > > > Bindings are added. Only one interrupt is needed because
> > > > > > > we do not yet employ the SCMI p2a channel.
> > > > > >
> > > > > > I still don't understand what this is. To repeat from v1: I thought SCMI
> > > > > > was a mailbox consumer, not provider?
> > > > >
> > > > > Hi Rob,
> > > > >
> > > > > I'm not sure where I am implying that SCMI is a mailbox provider?
> > > > > Should I not mention "SCMI" in the subject line?
> > > > >
> > > > > This is just a mailbox driver, "consumed" by SCMI. Our SCMI DT node
> > > > > looks like this:
> > > > >
> > > > > brcm_scmi_mailbox: brcm_scmi_mailbox@0 {
> > > > > #mbox-cells = <1>;
> > > > > compatible = "brcm,brcmstb-mbox";
> > > > > };
> > > > >
> > > > > brcm_scmi@0 {
> > > > > compatible = "arm,scmi";
> > > > > mboxes = <&brcm_scmi_mailbox 0>;;
> > > > > mbox-names = "tx";
> > > > > shmem = <&NWMBOX>;
> > > > > /* ... */
> > > > > };
> > > >
> > > > Okay, that makes more sense. Though it seems like this is just adding
> > > > a pointless level of indirection to turn an interrupt into a mailbox.
> > > > There's nothing more to 'the mailbox' is there?
> > >
> > > Correct. Although you can see that it uses both interrupts and SMC
> > > calls to get the job done.
> > >
> >
> > I was against having 2 separate solutions and would have raised my concern
> > again. As I mentioned earlier, either extend what we have or move the
> > existing SMC solution into this mailbox driver. Having 2 different solution
> > for this just because you have extra interrupt to deal with is definite
> > NACK from me as I had previously mentioned.
> >
> > > > So why not either
> > > > allow SCMI to have an interrupt directly
> > > Not sure here -- perhaps the SCMI folks have an answer?
> > >
> >
> > I did ask why can't you extend the existing SCMI/SMC binding to add this
> > as optional feature ?
> Hi Sudeep,
>
> Looking at the email you said, "In that case any reason why you can't
> reuse the existing smc transport for SCMI." , and I replied with the
> reason. I did not interpret your statement above as what you are
> clearly saying now: "either extend what we have or move the existing
> SMC solution into this mailbox driver. "
>
No, you are right. I didn't mention that explicitly. I wanted to, but
thought I will wait until this driver got traction to ask you to merge
them. Sorry for that. Anyways I am against having existing solution and
a mailbox for SMC, they need to be merged at any cost. Where the final
solution will be doesn't matter much to me, I am fine either way.
--
Regards,
Sudeep
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2020-11-05 19:05 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-29 19:59 [PATCH v4 0/2] mailbox: Add Broadcom STB mailbox driver for SCMI Jim Quinlan
2020-10-29 19:59 ` [PATCH v4 1/2] dt-bindings: Add bindings for BrcmSTB SCMI mailbox driver Jim Quinlan
2020-11-04 21:50 ` Rob Herring
2020-11-04 22:03 ` Jim Quinlan
2020-11-05 15:13 ` Rob Herring
2020-11-05 15:28 ` Jim Quinlan
2020-11-05 18:27 ` Sudeep Holla
2020-11-05 18:57 ` Jim Quinlan
2020-11-05 19:05 ` Sudeep Holla
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