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
Some SoC data requires huge alignments. E.g., the µDMA channel control table has
to be 1024-byte aligned. This table was simply aligned to 1024 bytes in the C
code, which had the following consequences, wasting a lot of RAM:
- As this table could be placed anywhere in .bss, there could be an alignment
gap of up to 1023 bytes between the preceding data and this table.
- The size of this table was also aligned to 1024 bytes, regardless of
UDMA_CONF_MAX_CHANNEL, making this configuration option supposed to save RAM
just useless.
- .bss was also aligned to at least 1024 bytes, creating a huge alignment gap
between .data and .bss.
Instead of relying on the compiler to force this alignment, and on the linker to
automatically place data, this change places carefully such SoC data in RAM
using the linker script. A dedicated section is created to place such SoC data
requiring huge alignments, and it is put at the beginning of the SRAM in order
to ensure a maximal alignment without any gap. In this way, the alignment of
.bss also remains normal, and the size of this table is not constrained by its
alignment, but only by its contents (i.e. by UDMA_CONF_MAX_CHANNEL).
In the case of the µDMA channel control table, the data is still zeroed by
udma_init() (instead of also being zeroed as part of .bss).
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
When returning from PM1/2, the sleep timer value (used by RTIMER_NOW()) is not
up-to-date until a positive edge on the 32-kHz clock has been detected after the
system clock restarted. To ensure an updated value is read, wait for a positive
transition on the 32-kHz clock by polling the SYS_CTRL_CLOCK_STA.SYNC_32K bit,
before reading the sleep timer value.
Because of this RTIMER_NOW() fixup, lpm_exit() has to be called at the very
beginning of ISRs waking up the SoC. This also ensures that all clocks and
timers are enabled at the correct frequency and updated before using them
following wake-up.
Without this fix, etimers could sometimes (randomly, depending on timings)
become ultra slow (observed from 10x to 40x slower than normal) if the system
exited PM1/2 very often. This issue occurred more often with PM1.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Create a dedicated header file with all the definitions for the flash lock bit
page and customer configuration area. This avoids duplicating those definitions
in the startup-gcc.c files of all CC2538-based platforms, and this also allows
to easily manipulate the CCA from outside startup-gcc.c (e.g. for on-the-air
firmware update).
The definitions are now complete contrary to what was in startup-gcc.c:
- Definitions have been added to select the bootloader backdoor pin and active
level if enabled.
- Definitions have been added to access the page and debug lock bits. The debug
lock bit can be used to prevent someone from reading back a programmed
firmware through JTAG if the firmware binary image has to be confidential,
which should be combined with a disabled bootloader backdoor.
- The application entry point is now tied to the beginning of the .text section
instead of to the beginning of the flash. This allows projects using custom
linker scripts to place the application entry point anywhere in the flash,
which can be useful e.g. for on-the-air firmware update.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
The pending GPIO power-up interrupts have to be cleared in the ISRs in order not
to re-trigger the interrupts and the wake-up events.
The power-up interrupts of all pins are cleared for each port in the
corresponding port ISR. This is done after calling the registered callbacks so
that the callbacks can know which pin woke up the SoC. This is done after
clearing the regular interrupt in order to avoid getting a new wake-up interrupt
without the regular interrupt in the case of a new wake-up edge occurring
between the two clears.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
The GPIO power-up interrupts have to be configured and enabled in order to be
able to wake-up the SoC from PM1+ upon a signal edge occurring on a GPIO input
pin.
This set of macros allows to:
- configure the signal edge triggering a power-up interrupt,
- enable and disable a power-up interrupt,
- clear a power-up interrupt flag.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Homogenize port and pin definitions naming:
- PERIPHERAL_FUNCTION_PORT for the port ID,
- PERIPHERAL_FUNCTION_PIN for the pin ID,
- PERIPHERAL_FUNCTION_PORT_BASE for the port base,
- PERIPHERAL_FUNCTION_PIN_MASK for the pin mask.
Define only PERIPHERAL_FUNCTION_PORT and PERIPHERAL_FUNCTION_PIN in board.h, and
deduce PERIPHERAL_FUNCTION_PORT_BASE and PERIPHERAL_FUNCTION_PIN_MASK in the
driver from the former definitions.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Use the GPIO accessor macros instead of copying raw register access code all
over the place. This is cleaner and less error prone.
This fixes the setting of the USB pull-up resistor that worked only by chance on
the CC2538DK because it is controlled by the pin 0 of the used GPIO port.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Introduce new useful GPIO macros to:
- read the levels of some port pins,
- write the levels of some port pins (pass bit-field value to be set),
- clear the interrupt flags for some port pins.
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@advansee.com>
The parameters in the GPIO macros were used without being parenthesized. This
could generate wrong values for register assignments in the case of expressions
passed as arguments to these macros.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
lpm_enter() must not enter PM1+ if the UART TX FIFO is not empty. Otherwise, the
UART clock gets disabled, and its TX is broken.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
spi-arch.h configures dev/spi.h, so it must be #included first. Luckily, this
mistake did not have any consequence here, but fix it in order to avoid possible
future issues.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
If the SSI has never been used and spi_init() is called, then the SSI receive
FIFO is empty and remains so, so calling SPI_WAITFOREORx() at the end of
spi_init() waits endlessly for SSI_SR.RNE to be set. Hence, this call must be
removed in order to avoid a deadlock.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
This uses the core/dev/spi.h header and implements the spi_init()
function and the various macros for SPI operation. ssi.h contains all of
the register locations and information.
This implementation is not very versatile, mostly because I don't how to
make it flexible in the contiki system. It supports pin muxing for the
four spi pins, but other than that picks sensible defaults.
The SPI macros (like SPI_READ()) are defined in
cpu/cc2538/spi-arch.h. In order to use the SPI driver, add the following
includes to your project:
#include "spi-arch.h
#include "dev/spi.h"
