On 03/12/15 15:08, Rob Herring wrote:
On Thu, Dec 3, 2015 at 4:14 AM, Martyn Welch
<martyn.welch@xxxxxxxxxxxxxxx> wrote:
On 02/12/15 15:15, Rob Herring wrote:
On Tue, Dec 01, 2015 at 07:12:49PM +0000, Martyn Welch wrote:
This patch adds documentation for the chromeos-firmware binding.
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Pawel Moll <pawel.moll@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Ian Campbell <ijc+devicetree@xxxxxxxxxxxxxx>
Cc: Kumar Gala <galak@xxxxxxxxxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: Martyn Welch <martyn.welch@xxxxxxxxxxxxxxx>
---
.../devicetree/bindings/misc/chromeos-firmware.txt | 27
++++++++++++++++++++++
bindings/firmware/ please.
1 file changed, 27 insertions(+)
create mode 100644
Documentation/devicetree/bindings/misc/chromeos-firmware.txt
diff --git a/Documentation/devicetree/bindings/misc/chromeos-firmware.txt
b/Documentation/devicetree/bindings/misc/chromeos-firmware.txt
new file mode 100644
index 0000000..8240611
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/chromeos-firmware.txt
@@ -0,0 +1,27 @@
<snip>
+
+Each signal is represented as a sub-node of "chromeos_firmware":
+Subnode properties:
+
+ - gpios: OF device-tree gpio specification.
+
+Example nodes:
+
+ chromeos_firmware {
This should go under /firmware
I've changed this to be:
firmware {
chromeos {
...
};
];
Which I generally accept (assuming this is considered a part of the
firmware) as a better way to represent this in the device tree, however this
has the nasty side effect of causing the device tree parsing to avoid
parsing the chromeos child and seeing it's compatible property (as the
firmware node isn't a bus), resulting in the probe routine not being called.
If I add a 'compatible = "simple-bus"' property to the firmware node it
works, but this doesn't seem quite right as I believe "simple-bus" is
defined as a "simple memory mapped bus".
I /could/ rewrite the initialisation to call of_find_compatible_node(), but
this seems rather hacky and inefficient. I can think of 2 other ways this
could be resolved:
(1) As this is only tangentially related to firmware, I rename it something
like "chromeos-signals" and make it it's own node. In essence this driver
provides a mechanism built on top of specific GPIO (ala gpio-keys seems to
be, after-all this has a similar use of resources to that).
I'm starting to fail to understand the relationship to firmware here...
gpio-keys are at least a thing (being a key or set of keys). Your
grouping is a rather random collection of GPIOs. Maybe you need
"gpio-switch" binding and then the function would be "label" property.
So, something like this:
gpio-switch {
compatible = "gpio-switch";
pinctrl-names = "default";
pinctrl-0 = <&wp_gpio &dev_mode &rec_mode>;
write-protect {
label = "write-protect";
gpios = <&gpx3 0 GPIO_ACTIVE_LOW>;
read-only;
};
developer-switch {
label = "developer-switch";
gpios = <&gpx1 3 GPIO_ACTIVE_HIGH>;
read-only;
};
recovery-switch {
label = "recovery-switch";
gpios = <&gpx0 7 GPIO_ACTIVE_LOW>;
read-only;
};
};
(Making it much more generic in the process.)
(2) Add a compatible string something like 'compatible="logical-group";' to
the firmware node and add that too the bus matching logic. This would have
the advantage of solving this in the general case (I guess there are other
instances where a grouping of things more logically rather than physically
connected would ideally be grouped together), though I expect there may be
some strong views regarding this approach.
Why do you need them grouped?
That's effectively what is achieved by putting this (and I assume
anything else considered "firmware" under a firmware node isn't it? (or
and I miss-understanding your request?)
I think it is a moot point, I'll rework as you've suggested.
Martyn
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