The Broadcom 283x SoCs feature multiple UARTs: the mostly used
"Mini-UART", which is an 8250 compatible IP, and at least one PL011.
While the 8250 is usually used for serial console purposes, it suffers
from a design flaw, where its clock depends on the VPU clock, which can
change at runtime. This will reliably mess up the baud rate.
To avoid this problem, people might choose to use the PL011 UART for
the serial console, which is pin-mux'ed to the very same GPIO pins.
This can be done by adding "miniuart-bt" to the "dtoverlay=" line in
config.txt.
To prepare for this situation, use the newly gained freedom of sharing
one console_t pointer across different UART drivers, to introduce the
option of choosing the PL011 for the console.
This is for now hard-coded to choose the Mini-UART by default.
A follow-up patch will introduce automatic detection.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Change-Id: I8cf2522151e09ff4ff94a6d396aec6fc4b091a05
In the wake of the upcoming unification of the console setup code
between RPi3 and RPi4, extend the "clock-less" setup scheme to the
RPi3. This avoid programming any clocks or baud rate registers,
which makes the port more robust against GPU firmware changes.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Change-Id: Ida83a963bb18a878997e9cbd55f8ceac6a2e1c1f
The location of the MMIO window is different between a Raspberry Pi 3
and 4: the former has it just below 1GB, the latter below 4GB.
The relative location of the peripherals is mostly compatible though.
To allow sharing code between the two models, let's rename the symbol
used for the MMIO base to the more generic RPI_IO_BASE name.
Change-Id: I3c2762fb30fd56cca743348e79d72ef8c60ddb03
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
With the advent of Raspberry Pi 4 support, we need to separate some
board specific headers between the RPi3 and RPi4.
Rename and move the "rpi3_hw.h" header, so that .c files just include
rpi_hw.h, and automatically get the correct version.
Change-Id: I03b39063028d2bee1429bffccde71dddfe2dcde8
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Andre Przywara