Add a version of `mutex_lock()` that can be canceled with the obvious name
`mutex_lock_cancelable()`. This function returns `0` on success, and
`-ECANCELED` when the calling thread was unblocked via a call to
`mutex_cancel()` (and hence without obtaining the mutex).
This is intended to simplify the implementation of `xtimer_mutex_lock_timeout()`
and to implement `ztimer_mutex_lock_timeout()`.
This patch implements the real time clock module for the QN908X cpus.
This module is very straightforward with only the one notable drawback
that it doesn't have a match register like the CTIMER block to implement
the alarm function. Instead, this driver can only use the interrupt
generated ever 1 second to implement the alarm match comparison in
software.
The IRQ for each GPIO port needs to be enabled in the NVIC on top of
enabling the corresponding bit in the GPIO port.
This was not caught in tests before because I was testing with a larger
stack of commits (including UART and timers) which also had this fix.
Manually poking the GPIOs while using tests/periph_gpio now properly
fires the interrupts.
The QN908x CPU has several timer modules: one RTC (Real-Time Clock) that
can count from the 32kHz internal clock or 32.768 kHz external clock,
four CTIMER that use the APB clock and have four channels each and one
SCT timer with up to 10 channels running on the AHB clock.
This patch implements a timer driver for the CTIMER blocks only, which
is enough to make the xtimer module work. Future patches should improve
on this module to support using the RTC CNT2 32-bit free-running
counter unit and/or the SCT timer.
GPIO_BOTH gpio_flank_t; UART_PARTY_MARK and UART_PARTY_SPACE in
uart_parity_t; and UART_DATA_BITS_5 and UART_DATA_BITS_6
uart_data_bits_t enum values where missing from the periph_cpu.h header
since they are not supported by the CPU. This was causing some tests to
fail to compile, but only after adding the periph_timer module.
This patch adds those missing macros and makes the corresponding
functions fail when trying to use them.
A minor fix to the NWDT_TIME_LOWER_LIMIT value setting it to 1U to avoid
a -Werror=type-limits error in the tests/periph_wdt test. In theory 0
is a totally valid value although a bit useless since it will trigger
the WDT right away.
