[PATCH v8 1/5] Documentation: add sbsa-gwdt driver documentation

From: fu . wei
Date: Tue Oct 27 2015 - 12:07:34 EST

From: Fu Wei <fu.wei@xxxxxxxxxx>

The sbsa-gwdt.txt documentation in devicetree/bindings/watchdog is for
introducing SBSA(Server Base System Architecture) Generic Watchdog
device node info into FDT.

Also add sbsa-gwdt introduction in watchdog-parameters.txt

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
.../devicetree/bindings/watchdog/sbsa-gwdt.txt | 46 ++++++++++++++++++++++
Documentation/watchdog/watchdog-parameters.txt | 6 +++
2 files changed, 52 insertions(+)

diff --git a/Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt b/Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt
new file mode 100644
index 0000000..ad8e99a
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt
@@ -0,0 +1,46 @@
+* SBSA (Server Base System Architecture) Generic Watchdog
+The SBSA Generic Watchdog Timer is used to force a reset of the system
+after two stages of timeout have elapsed. A detailed definition of the
+watchdog timer can be found in the ARM document: ARM-DEN-0029 - Server
+Base System Architecture (SBSA)
+Required properties:
+- compatible: Should at least contain "arm,sbsa-gwdt".
+- reg: Each entry specifies the base physical 64-bit address of a register
+ frame and the 64-bit length of that frame; currently, two frames must be
+ defined, in this order:
+ 1: Watchdog control frame
+ 2: Refresh frame.
+- interrupts: At least one interrupt must be defined that will be used as
+ the WS0 interrupt. A WS1 interrupt definition can be provided, but is
+ optional. The interrupts must be defined in this order:
+ 1: WS0 interrupt
+ 2: WS1 interrupt
+Optional properties
+- timeout-sec: To use a timeout value that is different from the driver
+ default values, use this property. If used, at least one timeout value
+ (in seconds) must be provided. A second optional timeout value (in
+ seconds) may also be provided and will be used as the pre-timeout value,
+ if it is given.
+ There are two possible sources for driver default timeout values:
+ (1) the driver contains hard-coded default values, or
+ (2) module parameters can be given when the module is loaded
+ If timeout/pretimeout values are provided when the module loads, they
+ will take priority. Second priority will be the timeout-sec from DTB,
+ and third the hard-coded driver values.
+Example for FVP Foundation Model v8:
+watchdog@2a440000 {
+ compatible = "arm,sbsa-gwdt";
+ reg = <0x0 0x2a440000 0 0x1000>,
+ <0x0 0x2a450000 0 0x1000>;
+ interrupts = <0 27 4>;
+ timeout-sec = <60 30>;
diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt
index 9f9ec9f..e62c8c4 100644
--- a/Documentation/watchdog/watchdog-parameters.txt
+++ b/Documentation/watchdog/watchdog-parameters.txt
@@ -284,6 +284,12 @@ sbc_fitpc2_wdt:
margin: Watchdog margin in seconds (default 60s)
nowayout: Watchdog cannot be stopped once started
+timeout: Watchdog timeout in seconds. (default 60s)
+pretimeout: Watchdog pretimeout in seconds. (default 30s)
+nowayout: Watchdog cannot be stopped once started
+ (default=kernel config parameter)
isapnp: When set to 0 driver ISA PnP support will be disabled (default=1)
io: io port

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