This patchset adds the basic infrastructure to periodically execute code, e.g. all 100ms. Examples for such functions might be LED blinking etc. The functions that are hooked into this cyclic list should be small timewise as otherwise the execution of the other code that relies on a high frequent polling (e.g. UART rx char ready check) might be delayed too much. This patch also adds the Kconfig option CONFIG_CYCLIC_MAX_CPU_TIME_US, which configures the max allowed time for such a cyclic function. If it's execution time exceeds this time, this cyclic function will get removed from the cyclic list.
How is this cyclic functionality executed? This patchset integrates the main function responsible for calling all registered cyclic functions cyclic_run() into the common WATCHDOG_RESET macro. This guarantees that cyclic_run() is executed very often, which is necessary for the cyclic functions to get scheduled and executed at their configured periods.
This cyclic infrastructure will be used by a board specific function on the NIC23 MIPS Octeon board, which needs to check periodically, if a PCIe FLR has occurred.
Ideas how to continue: One idea is to rename WATCHDOG_RESET to something like SCHEDULE and move the watchdog_reset call into this cyclic infrastructure as well. Or to perhaps move the shell UART RX ready polling to a cyclic function.
It's also possible to extend the "cyclic" command, to support the creation of periodically executed shell commands (for testing etc).
Thanks, Stefan
Aaron Williams (1): mips: octeon_nic23: Add PCIe FLR fixup via cyclic infrastructure
Stefan Roese (6): time: Import time_after64() and friends from Linux cyclic: Add basic support for cyclic function execution infrastruture cyclic: Integrate cyclic infrastructure into WATCHDOG_RESET cyclic: Integrate cyclic functionality at bootup in board_r/f cyclic: Add 'cyclic list' command sandbox: Add cyclic demo function
MAINTAINERS | 7 + board/Marvell/octeon_nic23/board.c | 197 +++++++++++++++++++++++++++++ board/sandbox/sandbox.c | 15 +++ cmd/Kconfig | 6 + cmd/Makefile | 1 + cmd/cyclic.c | 40 ++++++ common/Kconfig | 22 ++++ common/Makefile | 1 + common/board_f.c | 2 + common/board_r.c | 2 + common/cyclic.c | 112 ++++++++++++++++ configs/octeon_nic23_defconfig | 3 + configs/sandbox_defconfig | 2 + fs/cramfs/uncompress.c | 2 +- include/cyclic.h | 84 ++++++++++++ include/time.h | 19 +++ include/watchdog.h | 23 +++- 17 files changed, 534 insertions(+), 4 deletions(-) create mode 100644 cmd/cyclic.c create mode 100644 common/cyclic.c create mode 100644 include/cyclic.h