When we communicate with the VideoCore to perform property mailbox
transactions, that is a DMA operation as far as the property buffer
is concerned. Use phys_to_bus() on that buffer.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
BCM2835 (used on Raspberry Pi) and BCM2836 (used on Raspberry Pi 2)
are similar enough. One of the biggest differences is the ARM
processor. It is reasonable to collect the source files into a
single place, arch/arm/mach-bcm283x/.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
My original intention was to have a 100ms timeout. However, the timer
operations used return values in ms not us, so we ended up with a 100s
timeout instead. Fixing this exposes that some operations need longer
to operate than 100ms, so bump the timeout up to a whole second.
Reported-by: Andre Heider <a.heider@gmail.com>
Reviewed-by: Andre Heider <a.heider@gmail.com>
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
The BCM2835 SoC contains (at least) two CPUs; the VideoCore (a/k/a "GPU")
and the ARM CPU. The ARM CPU is often thought of as the main CPU.
However, the VideoCore actually controls the initial SoC boot, and hides
much of the hardware behind a protocol. This protocol is transported
using the SoC's mailbox hardware module.
Here, we add a very simplistic driver for the mailbox module, and define
a few structures for the property messages.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Stephen Warren
Masahiro Yamada
Wolfgang Denk