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authorStephan Olbrich <stephanolbrich@gmx.de>2016-02-14 11:04:28 +0100
committerMark Brown <broonie@kernel.org>2016-02-15 20:45:19 +0000
commitb4e2adef62062cf716d1c81adc12ad6def516f72 (patch)
treec18a2f0cfccffb6f23757cb9552e9d4e9fe60d54 /Makefile
parentf29ab1845f3e2684ba1c6de6c3bd5198e4b1459c (diff)
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spi: bcm2835aux: set up spi-mode before asserting cs-gpio
When using reverse polarity for clock (spi-cpol) on a device the clock line gets altered after chip-select has been asserted resulting in an additional clock beat, which confuses hardware. This happens due to the fact, the the hardware was initialized and reset at the begin and end of each transfer which results in default state for all lines except chip-select which is handled by the spi-subsystem as gpio-cs is used. To avoid this situation this patch moves the setup of polarity (spi-cpol and spi-cpha) outside of the chip-select into prepare_message, which is run prior to asserting chip-select. Signed-off-by: Stephan Olbrich <stephanolbrich@gmx.de> Reviewed-by: Martin Sperl <kernel@martin.sperl.org> Tested-by: Martin Sperl <kernel@martin.sperl.org> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Mark Brown <broonie@kernel.org>
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0 files changed, 0 insertions, 0 deletions
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