Since https://github.com/RIOT-OS/RIOT/pull/20935 gpio_write()
uses a `bool` instead of an `int`. This does the same treatment for
`gpio_read()`.
This does indeed add an instruction to `gpio_read()` implementations.
However, users caring about an instruction more are better served with
`gpio_ll_read()` anyway. And `gpio_read() == 1` is often seen in
newcomer's code, which would now work as expected.
On SAM L21 only 8 EXTWAKE pins can wake the CPU from Backup sleep.
Handle this analogous to the RTC tamper pins on SAM D5x/E5x where
configuring them as an interrupt will also cause them to wake the
device from Deep Sleep.
On samd5x only the RTC can wake the CPU from Deep Sleep (pm modes 0 & 1).
The external interrupt controller is disabled, but we can use the tamper
detection of the RTC.
If an gpio interrupt is configured on one of the five tamper detect pins,
those can be used to wake the CPU from Deep Sleep / Hibernate.
The Cortex-m0 based ATSAM devices can use the Single-cycle I/O Port for
GPIO. This commit modifies the gpio_t type to use this port when
available. It is mapped back to the peripheral memory space for
configuration access. When it is not available, the _port_iobus() and
_port() functions behave identical, which is the case for the samd51.
If we disable an external interrupt, GPIO events that would generate an interrupt will still set the interrupt flag.
That means once we enable the interrupt again, a stale interrupt will be triggered.
This is surprising and probably not what the user wants, unfortunately the API documentation is not very clear about what to expect.
There is however no way to drop those intermediate interrupts with the current API.
Ignoring the events that occurred while the GPIO interrupt were disabled is probably the right (and expected) thing to.
Currently only samd21 used the 32 kHz clock for EXTI which makes it miss fast events.
All newer members of the family use the MAIN clock.
While touching this, also make the clock source configurable to this can be overwritten,
e.g. in the board config if desired.
For consistency, use named GCLKs.
- `SAM0_GCLK_32KHZ` will always be 2 for samd21
- `SAM0_GCLK_MAIN` will always be 0
So no change in functionality, just makes the code easier to understand.
_exti() always assumes only 2 ports, so it will always fail when using
e.g. port C or port D on same54.
Instead, determine the number of ports from the dimensions of the exti_config
array.
This adds supoprt for the Atmel SAMD51 & SAME54 SoC.
The SAME5x/SAMD5x is a line of Cortex-M4F MCUs that share peripherals
with the samd2x Cortex-M0+ and saml1x Cortex-M23 parts.
