spi: imx: Use dynamic bursts only when bits_per_word is 8, 16 or 32

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The dynamic bursts mode allows to group together multiple words into a
single burst. To do so, it's necessary that words can be packed into the
32-bits FIFO entries, so we can't allow using this mode with bit_per_words
different to 8, 16 or 32.

This prevents shitfing out extra clock ticks for transfers with
bit_per_word values not aligned on 8 bits.

With that , we are sure that only the correct number of bits is
shifted out at each transfer, so we don't need to mask out the remaining
parts of the words.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

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Maxime Chevallier 2018-07-17 16:31:51 +02:00 • committed by Mark Brown

parent a021cac420

commit 2801b2f5fa

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drivers/spi/spi-imx.c

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