| Message ID | 1445961999-9506-2-git-send-email-fu.wei@linaro.org |
|---|---|
| State | New |
| Headers | show |
Hi Timur On 31 October 2015 at 01:46, Timur Tabi <timur@codeaurora.org> wrote: > On Tue, Oct 27, 2015 at 11:10 PM, Fu Wei <fu.wei@linaro.org> wrote: >> >>> Why is WS1 optional? >> >> According to the description of WS1 in SBSA 2.3 (5.2 Watchdog Operation) page 21 >> ----------------- >> The signal is fed to a higher agent as an interrupt or reset for it to >> take executive action. >> ---------------- >> >> So WS1 maybe a interrupt. >> >> In a real Hardware, WS1 hooks to a reset signal pin of BMC, if this >> pin is triggered, BMC will do a real warm reset. >> In this case, WS1 is a reset, Linux doesn't need to deal with that. >> >> For now , I haven't found a hardware use WS1 as interrupt. >> In <ARM v8-A Foundation Platform User Guide> 3.2 Interrupt maps Page 22 >> Table 3-3 Shared peripheral interrupt assignments >> IRQ ID SPI offset Device >> 60 28 EL2 Generic Watchdog WS1 >> >> But I don't have further info about it. >> >> Anyway, because this signal could be interrupt or reset, Linux don't >> need know this signal sometimes. >> So I think it should be optional in binding info. >> >> Do I miss something? Any suggestion ? Please correct me, thanks. > > I think maybe Mark was asking why WS1 is optional, not the WS1 My answer is for "why WS1 is optional"! > interrupt. Maybe you can reword the documentation to make is clear > that I didn't say : "only the *interrupt* for WS1 is optional." > > However, the ACPI table only allows for one interrupt, and it's not > clear whether that's the WS0 or WS1 interrupt. So if both WS0 and WS1 > generate an interrupt, how does the driver handle that? register a interrupt handle for both > > -- > Qualcomm Innovation Center, Inc. > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project. -- Best regards, Fu Wei Software Engineer Red Hat Software (Beijing) Co.,Ltd.Shanghai Branch Ph: +86 21 61221326(direct) Ph: +86 186 2020 4684 (mobile) Room 1512, Regus One Corporate Avenue,Level 15, One Corporate Avenue,222 Hubin Road,Huangpu District, Shanghai,China 200021 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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 ------------------------------------------------- +sbsa_gwdt: +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) +------------------------------------------------- sc1200wdt: isapnp: When set to 0 driver ISA PnP support will be disabled (default=1) io: io port