On Wed, 2021-02-03 at 14:41 -0600, Rob Herring wrote:
> On Wed, Feb 3, 2021 at 6:52 AM Damien Le Moal <Damien.LeMoal@xxxxxxx> wrote:
> >
> > On Tue, 2021-02-02 at 13:02 -0600, Rob Herring wrote:
> > > On Tue, Feb 2, 2021 at 4:36 AM Damien Le Moal <damien.lemoal@xxxxxxx> wrote:
> > > >
> > > > The sifive gpio IP block supports up to 32 GPIOs. Reflect that in the
> > > > interrupts property description and maxItems. Also add the standard
> > > > ngpios property to describe the number of GPIOs available on the
> > > > implementation.
> > > >
> > > > Also add the "canaan,k210-gpiohs" compatible string to indicate the use
> > > > of this gpio controller in the Canaan Kendryte K210 SoC. If this
> > > > compatible string is used, do not define the clocks property as
> > > > required as the K210 SoC does not have a software controllable clock
> > > > for the Sifive gpio IP block.
> > > >
> > > > Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
> > > > Cc: Rob Herring <robh@xxxxxxxxxx>
> > > > Cc: devicetree@xxxxxxxxxxxxxxx
> > > > Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
> > > > ---
> > > > .../devicetree/bindings/gpio/sifive,gpio.yaml | 21 ++++++++++++++++---
> > > > 1 file changed, 18 insertions(+), 3 deletions(-)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml b/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
> > > > index ab22056f8b44..2cef18ca737c 100644
> > > > --- a/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
> > > > +++ b/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
> > > > @@ -16,6 +16,7 @@ properties:
> > > > - enum:
> > > > - sifive,fu540-c000-gpio
> > > > - sifive,fu740-c000-gpio
> > > > + - canaan,k210-gpiohs
> > > > - const: sifive,gpio0
> > > >
> > > > reg:
> > > > @@ -23,9 +24,9 @@ properties:
> > > >
> > > > interrupts:
> > > > description:
> > > > - interrupt mapping one per GPIO. Maximum 16 GPIOs.
> > > > + interrupt mapping one per GPIO. Maximum 32 GPIOs.
> > > > minItems: 1
> > > > - maxItems: 16
> > > > + maxItems: 32
> > > >
> > > > interrupt-controller: true
> > > >
> > > > @@ -38,6 +39,10 @@ properties:
> > > > "#gpio-cells":
> > > > const: 2
> > > >
> > > > + ngpios:
> > > > + minimum: 1
> > > > + maximum: 32
> > >
> > > What's the default as obviously drivers already assume something.
> > >
> > > Does a driver actually need to know this? For example, does the
> > > register stride change or something?
> > >
> > > Please don't add it if the only purpose is error check your DT (IOW,
> > > if it just checks the max cell value in gpios phandles).
> >
> > If I remove that, make dtbs_check complains. Looking at othe gpio controller
> > bindings, they all have it. So isn't it better to be consistent, and avoid make
> > dtbs_check errors ?
>
> That would mean you are already using 'ngpios' and it is undocumented
> (for this binding). If already in use and possibly having users then
> that changes things, but that's not what the commit msg says.
>
> Not *all* gpio controllers have ngpios. It's a good number, but
> probably more than need it though. If we wanted it everywhere, there
> would be a schema enforcing that.
If I remove the minimum and maximum lines, I get this error:
./Documentation/devicetree/bindings/gpio/sifive,gpio.yaml:42:10: [error] empty
value in block mapping (empty-values)
CHKDT Documentation/devicetree/bindings/processed-schema-examples.json
/home/damien/Projects/RISCV/linux/Documentation/devicetree/bindings/gpio/sifive
,gpio.yaml: properties:ngpios: None is not of type 'object', 'boolean'
SCHEMA Documentation/devicetree/bindings/processed-schema-examples.json
/home/damien/Projects/RISCV/linux/Documentation/devicetree/bindings/gpio/sifive
,gpio.yaml: ignoring, error in schema: properties: ngpios
warning: no schema found in file:
./Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
If I remove the ngpios property entirely, then I get a hit on the device tree:
CHECK arch/riscv/boot/dts/canaan/sipeed_maix_bit.dt.yaml
/linux/arch/riscv/boot/dts/canaan/sipeed_maix_bit.dt.yaml:
gpio-controller@38001000: 'ngpios' does not match any of the regexes: 'pinctrl-
[0-9]+'
From schema:
/home/damien/Projects/RISCV/linux/Documentation/devicetree/bindings/gpio/sifive
,gpio.yaml
Now, If I change the property definition to this:
diff --git a/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
b/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
index 2cef18ca737c..5c7865180383 100644
--- a/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
+++ b/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
@@ -40,8 +40,11 @@ properties:
const: 2
ngpios:
- minimum: 1
- maximum: 32
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ The number of GPIO pins implemented by the controller.
+ It is 16 for the SiFive SoCs and 32 for the Canaan K210 SoC.
+
gpio-controller: true
Then all is OK.
Which option should I go for here ? If we want to avoid a dtbs_check error, as
far as I can see, we can:
1) Remove the ngpios property and remove its use from the DTS, which is not
nice in my opinion
2) Use the modification proposed above
Please advise. Thanks !
--
Damien Le Moal
Western Digital Research
