[PATCH 1/2] spi: bcm2835: add spi-bcm2835aux driver for the auxiliar spi1 and spi2

Noralf Trønnes noralf at tronnes.org
Sun Jul 5 03:37:56 PDT 2015

Den 05.07.2015 03:14, skrev Martin Sperl:
>> On 02.07.2015, at 06:57, Noralf Trønnes <noralf at tronnes.org> wrote:
>> Den 01.07.2015 21:39, skrev Martin Sperl:
>>>> On 30.06.2015, at 19:42, Mark Brown <broonie at kernel.org> wrote:
>>>> This looks relevant:
>>>>>>> On 22.06.2015, at 16:55, Jakub Kiciński <moorray3 at wp.pl> wrote:
>>>>>>> As mentioned by Noralf UART1 is quite commonly used on Compute Modules.
>>>>>>> Proper driver - perhaps modelled as a bus - seems like a prerequisite
>>>>>>> for this work.  You are also not using IRQ mux in DT binding example
>>>>>>> which is very misleading.


>> About sharing the aux interrupt, could this be implemented in irq-bcm2835
>> as a Bank 3?
> Obviously it could, but the question is if it is not more overhead than using
> a shared interrupt (requesting an interrupt with the shared flag set) in the
> first place (like this driver currently does or i2c and USB do).

I have looked closer at the 8250 serial driver, and in fact it has a
framework for writing 8250 like drivers. This makes it easy to extend
it to include support for the mini uart.
drivers/tty/serial/8250/8250_dw.c is an example of a driver that
overrides the interrupt handler. So a 8250_bcm2835.c can easily be
made with interrupt sharing as you suggest (and aux enabling). But
this means that the irq status register has to be included in the
syscon regmap as well.


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