8644553588
In case if the DW Watchdog IP core is synthesised with WDT_USE_FIX_TOP == false, the TOP interval indexes make the device to load a custom periods to the counter. These periods are hardwired at the IP synthesis stage and can be within [2^8, 2^(WDT_CNT_WIDTH - 1)]. Alas their values can't be detected at runtime and must be somehow supplied to the driver so one could properly determine the watchdog timeout intervals. For this purpose we suggest to have a vendor- specific dts property "snps,watchdog-tops" utilized, which would provide an array of sixteen counter values. At device probe stage they will be used to initialize the watchdog device timeouts determined from the array values and current clocks source rate. In order to have custom TOP values supported the driver must be altered in the following way. First of all the fixed-top values ready-to-use array must be determined for compatibility with currently supported devices, which were synthesised with WDT_USE_FIX_TOP == true. It will be used if either fixed TOP feature is detected being enabled or no custom TOPs are fetched from the device dt node. Secondly at the probe stage we must initialize an array of the watchdog timeouts corresponding to the detected TOPs list and the reference clock rate. For generality the procedure of initialization is designed in a way to support the TOPs array with no limitations on the items order or value. Finally the watchdog period search methods should be altered to support the new timeouts data structure. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200530073557.22661-5-Sergey.Semin@baikalelectronics.ru Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org> |
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| arch | ||
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| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
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| Kbuild | ||
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| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.