dt-bindings: pinctrl: qcom: add gpio-ranges, gpio-reserved-ranges

This patch adds the gpio-ranges and gpio-reserved-ranges property
definitions to the binding text files supported by the pinctrl-msm
driver framework.

gpio-ranges:
For DT-based platforms the pinctrl-msm framework currently relies
on the deprecated-for-DT gpiochip_add_pin_range() function to add
the range of GPIOs to be handled by the pin controller. Due to
interactions within gpiolib code, this causes the pinctrl-msm
driver to bail out (-517) during boot when a gpio-hog is declared.
This can be fatal and cause the system to not boot or reset
(for a detailed explanation and call-trace, refer to patch:
"pinctrl: msm: fix gpio-hog related boot issues" in this series).

gpio-reserved-ranges:
The binding has been added as a precaution since the TrustZone
firmware (aka QSEE), which is running as the hypervisor, might
have reserved certain, but undisclosed pins. Hence reading or
writing to the registers for those pins will cause an
XPU violation and this subsequently crashes the kernel.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pinctrl/qcom,msm8660-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/qcom,msm8660-pinctrl.txt
index df9a838ec5f9..cdc4787e59d2 100644
--- a/Documentation/devicetree/bindings/pinctrl/qcom,msm8660-pinctrl.txt
+++ b/Documentation/devicetree/bindings/pinctrl/qcom,msm8660-pinctrl.txt
@@ -10,6 +10,11 @@ Required properties:
 - #gpio-cells : Should be two.
                 The first cell is the gpio pin number and the
                 second cell is used for optional parameters.
+- gpio-ranges: see ../gpio/gpio.txt
+
+Optional properties:
+
+- gpio-reserved-ranges: see ../gpio/gpio.txt
 
 Please refer to ../gpio/gpio.txt and ../interrupt-controller/interrupts.txt for
 a general description of GPIO and interrupt bindings.
@@ -62,6 +67,7 @@ Example:
 
 		gpio-controller;
 		#gpio-cells = <2>;
+		gpio-ranges = <&msmgpio 0 0 173>;
 		interrupt-controller;
 		#interrupt-cells = <2>;
 		interrupts = <0 16 0x4>;