The LEDx_PIN may still be defined (eg. on the particle-mesh family
because it is used to configure the PWM pins); the IS_PRESENT macro
performs the stricter check ov testing for an _ON function.
It turns out that the feature to switch the GPIO direction quickly
is not only a way to emulate open drain / open source mode for less
sophisticated GPIO peripherals that do not natively support it.
It also enables tri-state output (push-pull high, push-pull low,
high impedance), which is useful e.g. for driven charlieplexed LEDs
quickly.
This changes the API by introducing a `gpio_ll_prepare_switch_dir()`
function that prepares the value used to identify which pins should
be switched to input or to output mode. This is useful for GPIO
peripherals in which the GPIO mode register does not allocate one bit
per pin (so that only the direction is given there), such as the one
for STM32. This allows an STM32 implementation in which preparing the
bitmask needed to modify the direction of pins is not trivial.
GPIO LL headers might be included even when not using GPIO LL. Some
functions may be provided by the common header or the platform specific
one, depending on the features used. Hence, the header can only be
safely included if the correct set of GPIO LL hardware features is used.
The assumption that every MCU has this feature turned out wrong. Hence,
add a feature to allow testing for support of edge triggered IRQs on
both flanks.
The API was based on the assumption that GPIO ports are mapped in memory
sanely, so that a `GPIO_PORT(num)` macro would work allow for constant
folding when `num` is known and still be efficient when it is not.
Some MCUs, however, will need a look up tables to efficiently translate
GPIO port numbers to the port's base address. This will prevent the use
of such a `GPIO_PORT(num)` macro in constant initializers.
As a result, we rather provide `GPIO_PORT_0`, `GPIO_PORT_1`, etc. macros
for each GPIO port present (regardless of MCU naming scheme), as well as
`GPIO_PORT_A`, `GPIO_PORT_B`, etc. macros if (and only if) the MCU port
naming scheme uses letters rather than numbers.
These can be defined as macros to the peripheral base address even when
those are randomly mapped into the address space. In addition, a C
function `gpio_port()` replaces the role of the `GPIO_PORT()` and
`gpio_port_num()` the `GPIO_PORT_NUM()` macro. Those functions will
still be implemented as efficient as possible and will allow constant
folding where it was formerly possible. Hence, there is no downside for
MCUs with sane peripheral memory mapping, but it is highly beneficial
for the crazy ones.
There are also two benefits for the non-crazy MCUs:
1. We can now test for valid port numbers with `#ifdef GPIO_PORT_<NUM>`
- This directly benefits the test in `tests/periph/gpio_ll`, which
can now provide a valid GPIO port for each and every board
- Writing to invalid memory mapped I/O addresses was treated as
triggering undefined behavior by the compiler and used as a
optimization opportunity
2. We can now detect at compile time if the naming scheme of the MCU
uses letters or numbers, and produce more user friendly output.
- This is directly applied in the test app
When WDT_HAS_INIT is non-zero (which it is for all but two supported
CPUs). The watchdog timer was not automatically started on boot when the
periph_wdt_auto_start module was enabled. This patch fixes this.
We occasionally have some public `foo.h` header that includes a private
`foo_arch.h` header. Users are expected to include the `foo.h` header
and not the `foo_arch.h`. However, clangd will claim that the `#include`
of `foo.h` is unused if only functions / macros/ types / ... from
`foor_arch.h` is used and nothing from `foo.h`.
This adds the `IWYU pragma: export` comment to the include of
`foo_arch.h` in `foo.h`, so that clangd treats functions / macros /
types provided by `foo_arch.h` as if they were instead provided by
`foo.h`, which fixes the false positives.
