summaryrefslogtreecommitdiffstats
path: root/Documentation/devicetree/bindings/arm/arch_timer.txt
diff options
context:
space:
mode:
authorBrian Norris <briannorris@chromium.org>2016-10-04 11:12:09 -0700
committerDaniel Lezcano <daniel.lezcano@linaro.org>2016-11-21 11:05:36 +0100
commitd8ec7595a013237f82d965dcf981571aeb41855b (patch)
tree098c25d78acbd3aa0f22a06c131fef47b674b692 /Documentation/devicetree/bindings/arm/arch_timer.txt
parentbaa73d9e478ff32d62f3f9422822b59dd9a95a21 (diff)
downloadlinux-d8ec7595a013237f82d965dcf981571aeb41855b.tar.bz2
clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend
The ARM specifies that the system counter "must be implemented in an always-on power domain," and so we try to use the counter as a source of timekeeping across suspend/resume. Unfortunately, some SoCs (e.g., Rockchip's RK3399) do not keep the counter ticking properly when switched from their high-power clock to the lower-power clock used in system suspend. Support this quirk by adding a new device tree property. Signed-off-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Diffstat (limited to 'Documentation/devicetree/bindings/arm/arch_timer.txt')
-rw-r--r--Documentation/devicetree/bindings/arm/arch_timer.txt5
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/arch_timer.txt b/Documentation/devicetree/bindings/arm/arch_timer.txt
index ef5fbe9a77c7..ad440a2b8051 100644
--- a/Documentation/devicetree/bindings/arm/arch_timer.txt
+++ b/Documentation/devicetree/bindings/arm/arch_timer.txt
@@ -38,6 +38,11 @@ to deliver its interrupts via SPIs.
architecturally-defined reset values. Only supported for 32-bit
systems which follow the ARMv7 architected reset values.
+- arm,no-tick-in-suspend : The main counter does not tick when the system is in
+ low-power system suspend on some SoCs. This behavior does not match the
+ Architecture Reference Manual's specification that the system counter "must
+ be implemented in an always-on power domain."
+
Example: