Set the defalut value of SYS_CLOCK_HW_CYCLES_PER_SEC Kconfig option
from the Device Tree. The `clock-frequency` property of the DT cpu@0
node is a single source of truth defining the CPU frequency. This is
the value used e.g. by all Atmel drivers.
For Atmel SAM family CPU clock is currently the only supported system
clock source. Ensure that kernel understanding of the hardware clock
frequency is the correct one.
Signed-off-by: Piotr Mienkowski <piotr.mienkowski@gmail.com>
The SAM4L have a unique I2C driver. It shares simultaneously pins for
both master and slave controllers. Each controller have their own
instance. This introduces the TWIM controller that handles only the
master part.
The TWIM controller uses no copy and the driver was prepared to work
with both 7 and 10 bits address. The controller can handler up to 256
bytes for a single transfer allowing long data communication with
almost no CPU intervention.
The driver was wrote specifically to Zephyr. It receives a transfer
list of from upper layers to a specific device on the bus. It programs
the first and second transfer, if it exists, before start. At end of
full read/write interrupt, will program the next data block. This
process repeats until all transfers be executed. The driver uses
interrupt from TWIM to check for erros or program next tranfer.
Future work can enable low power mode on the driver allowing long
transfers with low power consumption.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Piotr Mienkowski