This adds the ngpios property to MMIO GPIO. We restrict the
property to 1..63 since there is no point in 0 GPIO lines and
we support up to 64bits wide registers for now.
Acked-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
Documentation/devicetree/bindings/gpio/gpio-mmio.yaml | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/gpio/gpio-mmio.yaml b/Documentation/devicetree/bindings/gpio/gpio-mmio.yaml
index b394e058256e..87e986386f32 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-mmio.yaml
+++ b/Documentation/devicetree/bindings/gpio/gpio-mmio.yaml
@@ -37,7 +37,8 @@ properties:
description:
A list of registers in the controller. The width of each register is
determined by its size. All registers must have the same width. The number
- of GPIOs is set by the width, with bit 0 corresponding to GPIO 0.
+ of GPIOs is set by the width, with bit 0 corresponding to GPIO 0, unless
+ the ngpios property further restricts the number of used lines.
items:
- description:
Register to READ the value of the GPIO lines. If GPIO line is high,
@@ -74,6 +75,15 @@ properties:
native-endian: true
+ ngpios:
+ minimum: 1
+ maximum: 63
+ description:
+ If this property is present the number of usable GPIO lines are restricted
+ to the first 0 .. ngpios lines. This is useful when the GPIO MMIO register
+ has 32 bits for GPIO but only the first 12 are actually connected to
+ real electronics, and then we set ngpios to 12.
+
no-output:
$ref: /schemas/types.yaml#/definitions/flag
description:
@@ -111,6 +121,7 @@ examples:
compatible = "brcm,bcm6345-gpio";
reg-names = "dirout", "dat";
reg = <0xfffe0406 2>, <0xfffe040a 2>;
+ ngpios = <15>;
native-endian;
gpio-controller;
#gpio-cells = <2>;
--
2.46.2
