From: Chris Brandt <chris.brandt@renesas.com>
To: Wim Van Sebroeck <wim@iguana.be>,
Guenter Roeck <linux@roeck-us.net>,
Sebastian Reichel <sre@kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Simon Horman <horms@verge.net.au>,
Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-renesas-soc@vger.kernel.org, devicetree@vger.kernel.org,
linux-watchdog@vger.kernel.org,
Chris Brandt <chris.brandt@renesas.com>
Subject: [PATCH v3 0/3] watchdog: add wdt and reset for renesas r7s72100
Date: Wed, 1 Mar 2017 17:54:52 -0500 [thread overview]
Message-ID: <20170301225455.22818-1-chris.brandt@renesas.com> (raw)
Some Renesas SoCs do not have a reset register and the only way to do a SW
controlled reset is to use the watchdog timer. So while this series started
out by only adding a reset feature, now it's a full watchdog timer driver that
includes a reset handler.
The longest WDT overflow you can get with a RZ/A1 (R7S72100) with its 8-bit
wide counter is 125ms. Not very long.
However, by setting max_hw_heartbeat_ms, the watchdog core will now handle
pinging the WDT automatically and allow the user to set times as big as they
want. Therefore, the default timeout for this driver is 30 seconds.
Of course if system interrupts are disabled too long and wdt can't be pinged
by the watchdog core, then the system will reset before the user specified
timeout. But hey, it's better nothing.
This driver was tested on an RZ/A1 RSK board using watchdog-simple.c from
samples/watchdog/.
v3:
* changed from a reset driver to a watchdog timer driver
* use udelay(20) instead of msleep for reset handler
* added Reviewed-by for r7s72100.dtsi and renesas-wdt.txt
* added Acked-by for renesas-wdt.txt
v2:
* added to renesas-wdt.txt instead of creating a new file
* changed "renesas,r7s72100-reset" to "renesas,r7s72100-wdt"
* changed "renesas,wdt-reset" to "renesas,rza-wdt"
* added "renesas,rza-wdt" as a fallback
* added interupt property (even though it is not used)
* added clocks property
* changed hard coded register values to defines
* added msleep to while(1) loop
* removed unnecessary #include files
* added Reviewed-by: Geert Uytterhoeven for renesas-reset.c
Chris Brandt (3):
watchdog: add rza_wdt driver
watchdog: renesas-wdt: add support for rza
ARM: dts: r7s72100: Add watchdog timer
.../devicetree/bindings/watchdog/renesas-wdt.txt | 4 +-
arch/arm/boot/dts/r7s72100.dtsi | 7 +
drivers/watchdog/Kconfig | 8 +
drivers/watchdog/Makefile | 1 +
drivers/watchdog/rza_wdt.c | 208 +++++++++++++++++++++
5 files changed, 227 insertions(+), 1 deletion(-)
create mode 100644 drivers/watchdog/rza_wdt.c
--
2.10.1
next reply other threads:[~2017-03-01 22:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-01 22:54 Chris Brandt [this message]
[not found] ` <20170301225455.22818-1-chris.brandt-zM6kxYcvzFBBDgjK7y7TUQ@public.gmane.org>
2017-03-01 22:54 ` [PATCH v3 1/3] watchdog: add rza_wdt driver Chris Brandt
2017-03-01 22:54 ` [PATCH v3 3/3] ARM: dts: r7s72100: Add watchdog timer Chris Brandt
2017-03-02 9:08 ` Sergei Shtylyov
2017-03-02 13:49 ` Chris Brandt
2017-03-01 22:54 ` [PATCH v3 2/3] watchdog: renesas-wdt: add support for rza Chris Brandt
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