[PATCH v7 1/7] clocksource/drivers/clksrc-evt-probe: Describe with the DT both the clocksource and the clockevent
From: Alexander Kochetkov <hidden>
Date: 2017-03-22 15:50:26
Also in:
linux-devicetree, linux-rockchip, lkml
Subsystem:
clocksource, clockevent drivers, open firmware and flattened device tree bindings, the rest · Maintainers:
Daniel Lezcano, Thomas Gleixner, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
From: Daniel Lezcano <redacted>
The CLOCKSOURCE_OF_DECLARE() was introduced before the
CLOCKEVENT_OF_DECLARE() and that resulted in some abuse where the
clockevent and the clocksource are both initialized in the same init
routine.
With the introduction of the CLOCKEVENT_OF_DECLARE(), the driver can
now split the clocksource and the clockevent init code. However, the
device tree may specify a single node, so the same node will be passed
to the clockevent/clocksource's init function, with the same base
address.
with this patch it is possible to specify an attribute to the timer's node to
specify if it is a clocksource or a clockevent and define two timers node.
For example:
timer: timer at 98400000 {
compatible = "moxa,moxart-timer";
reg = <0x98400000 0x42>;
interrupts = <19 1>;
clocks = <&coreclk>;
clockevent;
};
timer: timer at 98400010 {
compatible = "moxa,moxart-timer";
reg = <0x98400010 0x42>;
clocks = <&coreclk>;
clocksource;
};
With this approach, we allow a mechanism to clearly define a clocksource or a
clockevent without aerobatics we can find around in some drivers:
timer-sp804.c, arc-timer.c, dw_apb_timer_of.c, mps2-timer.c,
renesas-ostm.c, time-efm32.c, time-lpc32xx.c.
Signed-off-by: Daniel Lezcano <redacted>
Signed-off-by: Alexander Kochetkov <redacted>
---
Documentation/devicetree/bindings/timer/timer.txt | 38 +++++++++++++++++++++
drivers/clocksource/clkevt-probe.c | 7 ++++
drivers/clocksource/clksrc-probe.c | 7 ++++
3 files changed, 52 insertions(+)
create mode 100644 Documentation/devicetree/bindings/timer/timer.txt
diff --git a/Documentation/devicetree/bindings/timer/timer.txt b/Documentation/devicetree/bindings/timer/timer.txt
new file mode 100644
index 0000000..f1ee0cf
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/timer.txt@@ -0,0 +1,38 @@ + +Specifying timer information for devices +======================================== + +The timer can be declared via the macro: + +CLOCKSOURCE_OF_DECLARE(name, init) if it is a clocksource +CLOCKEVENT_OF_DECLARE(name, init) if it is a clockevent + +The CLOCKSOURCE_OF_DECLARE() was introduced before the +CLOCKEVENT_OF_DECLARE() and that resulted in some abuse where the +clockevent and the clocksource are both initialized in the same init +routine. + +With the introduction of the CLOCKEVENT_OF_DECLARE(), the driver can +now split the clocksource and the clockevent init code. However, the +device tree may specify a single node, so the same node will be passed +to the clockevent/clocksource's init function, with the same base +address. It is possible to specify an attribute to the timer's node to +specify if it is a clocksource or a clockevent and define two timers +node. + +Example: + + timer: timer at 98400000 { + compatible = "moxa,moxart-timer"; + reg = <0x98400000 0x42>; + interrupts = <19 1>; + clocks = <&coreclk>; + clockevent; + }; + + timer: timer at 98400010 { + compatible = "moxa,moxart-timer"; + reg = <0x98400010 0x42>; + clocks = <&coreclk>; + clocksource; + };
diff --git a/drivers/clocksource/clkevt-probe.c b/drivers/clocksource/clkevt-probe.c
index eb89b50..fa02ac1 100644
--- a/drivers/clocksource/clkevt-probe.c
+++ b/drivers/clocksource/clkevt-probe.c@@ -37,6 +37,13 @@ int __init clockevent_probe(void) init_func = match->data; + /* + * The device node describes a clocksource, ignore it + * as we are in the clockevent init routine. + */ + if (of_property_read_bool(np, "clocksource")) + continue; + ret = init_func(np); if (ret) { pr_warn("Failed to initialize '%s' (%d)\n",
diff --git a/drivers/clocksource/clksrc-probe.c b/drivers/clocksource/clksrc-probe.c
index bc62be9..ce50f33 100644
--- a/drivers/clocksource/clksrc-probe.c
+++ b/drivers/clocksource/clksrc-probe.c@@ -38,6 +38,13 @@ void __init clocksource_probe(void) init_func_ret = match->data; + /* + * The device node describes a clockevent, ignore it + * as we are in the clocksource init routine. + */ + if (of_property_read_bool(np, "clockevent")) + continue; + ret = init_func_ret(np); if (ret) { pr_err("Failed to initialize '%s': %d",
--
1.7.9.5