The CC2538 the WDT cannot be stopped once it has been started.
The CC2530/1 WDT can be stopped if it is running in timer mode,
but it cannot be stopped once it has been started in watchdog mode.
Both platforms currently provide "dummy" implementations of `watchdog_stop()`,
one does nothing and the other one basically re-maps `_stop()` to
`_periodic()`.
This was originally done in order to provide implementations for all prototypes
declared in `core/dev/watchdog.h`. In hindsight and as per the discussion
in #1088, this is bad practice since, if the build succeeds, the caller will
expect that the WDT has in fact been stopped, when in reality it has not.
Since the feature (stopping the WDT) is unsupported by the hardware, this pull
removes those dummy implementations. Thus, we will now be able to reliably
detect - at build time - attempts at using this unsupported feature.
Only the interrupt flags that have been handled must be cleared.
Otherwise, if a new interrupt occurs after the interrupt statuses are
read and before they are cleared, then it is discarded without having
been handled. This issue was particularly likely with two interrupt
trigger conditions occurring on different pins of the same port in a
short period of time.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
Power-up interrupts do not always update the regular interrupt status.
Because of that, in order not to miss power-up interrupts, the ISR must
handle both the regular and the power-up interrupt statuses.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
Introduce new useful GPIO macros to:
- get the raw interrupt status of a port,
- get the masked interrupt status of a port,
- get the power-up interrupt status of a port.
These macros are cleaner and less error-prone than raw register access
code copied all over the place.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
OR-ing an offset to a base address instead of adding it is dangerous
because it can only work if the base address is aligned enough for the
offset.
Moreover, if the base address or the offset has a value unknown at
compile time, then the assembly instructions dedicated to 'base +
offset' addressing on most CPUs can't be emitted by the compiler because
this would require the alignment of the base address against the offset
to be known in order to optimize 'base | offset' into 'base + offset'.
In that case, the compiler has to emit more instructions in order to
compute 'base | offset' on most CPUs, e.g. on ARM, which means larger
binary size and slower execution.
Hence, replace all occurrences of 'base | offset' with 'base + offset'.
This must become a coding rule.
Here are the results for the cc2538-demo example:
- Compilation of uart_init():
* before:
REG(regs->base | UART_CC) = 0;
200b78: f446 637c orr.w r3, r6, #4032 ; 0xfc0
200b7c: f043 0308 orr.w r3, r3, #8
200b80: 2200 movs r2, #0
200b82: 601a str r2, [r3, #0]
* now:
REG(regs->base + UART_CC) = 0;
200b7a: 2300 movs r3, #0
200b7c: f8c4 3fc8 str.w r3, [r4, #4040] ; 0xfc8
- Size of the .text section:
* before: 0x4c7c
* now: 0x4c28
* saved: 84 bytes
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
Instead of requiring all calls to `watchdog_start` to be
wrapped inside `#if WATCHDOG_CONF_ENABLE` guards, we control
things from within the WDT driver itself.
This commit also includes some minor documentation and
indentation cleanups
* Decouple 64-bit address from LINKADDR_SIZE
* get and set object from/to the start/end of the src/dest buffer
* We expect size == 8 (rather than size < 8) for both get_ and set_object. Error otherwise
* The RF no longer sets parameters by itself. We let the platform do this, using the extended API.
This avoids the limitation of having a single UART available at runtime, without
duplicating code.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Because the CC2538 has a multi-byte SPI RX FIFO, flushing the buffer
requires more than just a single read. This adds a loop that empties the
entire RX buffer on a FLUSH().
Different SPI chips needs different SPI settings. This commit adds a
function that allows chip drivers to configure the SPI peripheral before
using it.
The frame pin the driver was using as a chip select does not work as
most devices expect it to. It toggles after every byte, and most chips
interpret that as end of message. To make drivers more reliable, each
chip driver should setup a GPIO and assert it as needed.
Contiki sometimes fails to boot correctly and locks up in
random_init()
This problem only manifests itself for specific versions
of the arm-gcc toolchain and then again only for specific
levels of optimisation (-Os vs -O2, depending on the
value of the SMALL make variable)
The lockup is caused when we write an RFCORE XREG before
the RF clock ungating has taken effect, which in turn
only occurs depending on the assembly generated for those
two instructions:
REG(SYS_CTRL_RCGCRFC) = 1;
REG(RFCORE_XREG_FRMCTRL0) = 0x00000008;
This commit makes the RNG wait for the ungating to take
effect before attempting to write the register
