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, 9 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pinctrl/qcom,msm8994-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/qcom,msm8994-pinctrl.txt
index 13cd629f896e..f15443f6e78e 100644
--- a/Documentation/devicetree/bindings/pinctrl/qcom,msm8994-pinctrl.txt
+++ b/Documentation/devicetree/bindings/pinctrl/qcom,msm8994-pinctrl.txt
@@ -42,6 +42,14 @@ MSM8994 platform.
 	Definition: must be 2. Specifying the pin number and flags, as defined
 		    in <dt-bindings/gpio/gpio.h>
 
+- gpio-ranges:
+	Usage: required
+	Definition:  see ../gpio/gpio.txt
+
+- gpio-reserved-ranges:
+	Usage: optional
+	Definition: see ../gpio/gpio.txt
+
 Please refer to ../gpio/gpio.txt and ../interrupt-controller/interrupts.txt for
 a general description of GPIO and interrupt bindings.
 
@@ -160,6 +168,7 @@ Example:
 		interrupts = <GIC_SPI 208 IRQ_TYPE_LEVEL_HIGH>;
 		gpio-controller;
 		#gpio-cells = <2>;
+		gpio-ranges = <&msmgpio 0 0 146>;
 		interrupt-controller;
 		#interrupt-cells = <2>;