spi: bcm2835: transform native-cs to gpio-cs on first spi_setup

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Transforms the bcm-2835 native SPI-chip select to their gpio-cs equivalent.

This allows for some support of some optimizations that are not
possible due to HW-gliches on the CS line - especially filling
the FIFO before enabling SPI interrupts (by writing to CS register)
while the transfer is already in progress (See commit: e3a2be3030)

This patch also works arround some issues in bcm2835-pinctrl which does not
set the value when setting the GPIO as output - it just sets up output and
(typically) leaves the GPIO as low.  When a fix for this is merged then this
gpio_set_value can get removed from bcm2835_spi_setup.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

...

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Martin Sperl 2015-04-06 17:16:31 +00:00 • committed by Mark Brown

parent e3a2be3030

commit a30a555d74

1 changed files with 44 additions and 5 deletions

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49

drivers/spi/spi-bcm2835.c

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