Thread (49 messages) 49 messages, 8 authors, 2015-03-09

[PATCH 03/14] clocksource: Add ARM System timer driver

From: mcoquelin.stm32@gmail.com (Maxime Coquelin)
Date: 2015-02-16 12:08:42
Also in: linux-api, linux-arch, linux-devicetree, linux-gpio, linux-serial, lkml

2015-02-15 23:31 GMT+01:00 Rob Herring [off-list ref]:
On Thu, Feb 12, 2015 at 11:45 AM, Maxime Coquelin
[off-list ref] wrote:
quoted
This patch adds clocksource support for ARMv7-M's System timer,
also known as SysTick.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
---
 .../devicetree/bindings/arm/system_timer.txt       | 15 +++++
Please include v7M in the name. System timer sounds very generic. This
is the only timer architecturally defined IIRC, so perhaps just
"armv7m_systick".
Ok, let's go for "armv7m_systick".
quoted
 drivers/clocksource/Kconfig                        |  7 ++
 drivers/clocksource/Makefile                       |  1 +
 drivers/clocksource/arm_system_timer.c             | 74 ++++++++++++++++++++++
Same here.
Agree, will be in the v2.
quoted
 4 files changed, 97 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/system_timer.txt
 create mode 100644 drivers/clocksource/arm_system_timer.c
diff --git a/Documentation/devicetree/bindings/arm/system_timer.txt b/Documentation/devicetree/bindings/arm/system_timer.txt
new file mode 100644
index 0000000..35268b7
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/system_timer.txt
@@ -0,0 +1,15 @@
+* ARM System Timer
+
+ARMv7-M includes a system timer, known as SysTick. Current driver only
+implements the clocksource feature.
+
+Required properties:
+- compatible : Should be "arm,armv7m-systick"
+- reg       : The address range of the timer
+- clocks     : The input clock of the timer
You may want to consider supporting "clock-frequency" here too. In
more simple chips you may just have fixed clocks and may want to run a
kernel with COMMON_CLK disabled for size savings.
Ok, I will add this option in the v2.
quoted
+
+systick: system-timer {
This should be "systick: timer at e000e010".

Same for your dts file.
Right, it will be fixed in the v2.

Thanks for the review,
Maxime
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help