It's rare to use all of a target's prerequisites in a recipe - replace
most cases with $< (the target's first prerequisite).
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Commit e18501d0 broke the build for targets that added objects to
klipper.elf via adding dependencies. Rework the build so that it is
possible to add objects to klipper.elf via a new OBJS_klipper.elf
makefile variable.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Some of the samd21 chips have limited memory - change the code to
reduce the size of global variables.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Use a local linker script instead of the linker script provided by
Atmel. This will allow Klipper to use dynamic memory allocation.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Most samd boards have the crystal and it does improve the clock
accuracy, so default to enabling it.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Add support for using the internal clocks (with USB clock recovery
mode if available) on the SAMD21. Don't use the internal clock if the
external crystal is requested (instead use the PLL synced to the
external 32Khz signal).
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Add support for USB clock recovery mode if an external 32Khz crystal
is not in use. If using an external crystal, then don't use the
internal 48Mhz DFLL48Mhz clock (just use the PLLs synced to the
external 32Khz signal).
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
The SAMD51 ADC is only clocked on rising edges (vs both rising and
falling edges on the SAMD21) and it has a greater minimum frequency
than the SAMD21. So, increase the ADC clock.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
The cpu is almost always 16Mhz and the serial port is almost always
UART0, so no need to prompt in the normal case.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Now that the internal DWT timer is used for software timers, there is
no need to clock the peripherals at a higher clock speed. Clock all
peripherals at 48Mhz and simplify the clock generation code.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Clearing the watchdog while it is in progress can cause bus stalls on
the SAMD21. It appears that clearing the watchdog on the SAMD51 can
cause lockups of the watchdog device.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
The sram matrix configuration is, bizarrely, configured with a slow
default. It will typically add an extra wait state to every memory
access. Set the matrix sram controller to improve the performance.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Avoid using the "low-level" library timing utilities. This is in
preparation for using SysTick as part of the timer implementation.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
The ARM CortexM3 (and later) chips almost always have a 32bit timer in
the "Debug and Watch Trace" (DWT) unit which resides within the cpu
core itself. This timer is generally faster to access than timers
located on the chip's peripheral bus. When combined with the standard
ARM SysTick timer it provides a (generally) portable mechanism to
implement Klipper's software timer mechanism. It's generally also
faster than using the vendor specific timers.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Kevin O'Connor