[PATCH 7/7] watchdog: orion: Update device-tree binding documentation

On Fri, Aug 23, 2013 at 07:04:51AM -0300, Ezequiel Garcia wrote:

On Thu, Aug 22, 2013 at 09:26:21PM -0400, Jason Cooper wrote:

quoted

On Thu, Aug 22, 2013 at 11:41:58AM -0300, Ezequiel Garcia wrote:

quoted

Change the 'reg' property meaning, by defining three required cells.
It's important to note this commit breaks DT-compatibility for this
device.

Cc: devicetree at vger.kernel.org
Signed-off-by: Ezequiel Garcia <redacted>
---
 Documentation/devicetree/bindings/watchdog/orion-wdt.txt | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/watchdog/orion-wdt.txt b/Documentation/devicetree/bindings/watchdog/orion-wdt.txt
index 5dc8d30..bb7f1a2 100644
--- a/Documentation/devicetree/bindings/watchdog/orion-wdt.txt
+++ b/Documentation/devicetree/bindings/watchdog/orion-wdt.txt

@@ -3,7 +3,10 @@
 Required Properties:
 
 - Compatibility : "marvell,orion-wdt"
-- reg		: Address of the timer registers
+- reg		: Three cells are required.
+		  First  cell contains the global timer control register.
+		  Second cell contains the watchdog counter register.
+		  Third  cell contains the RSTOUT register.
 
 Optional properties:
 

@@ -13,7 +16,9 @@ Example:
 
 	wdt at 20300 {
 		compatible = "marvell,orion-wdt";
-		reg = <0x20300 0x28>;
+		reg = <0x20300 0x4
+		       0x20324 0x4
+		       0x20108 0x4>;

I don't like this.  It reaches outside of the wdt register.  I think a
more clean way to do this is to do a provider/consumer relationship as
in reset.txt.  eg, here you would retain the original reg binding, and
add a reset phandle.

Mmm... I can't see how this fits a reset-controller usage.

The watchdog simply "enables" the RSTOUT bit that allows the whole SoC
to be reset when the watchdog counter expires.

The reset-controller seems to be meant to send reset signals to devices,
which is not this case.

What am I missing?

Another possible solution is to simply "enable" the RSTOUT bit for
watchdog somewhere in mach-{kirkwood,mvebu,...} at board boot-up time.

Do you think that would have any drawbacks?
-- 
Ezequiel Garc?a, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com