spi: imx: dynamic burst length adjust for PIO mode

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previously burst length (BURST_LENGTH) is always set to equal
to bits_per_word, causes a 10us gap between each word in
transfer, which significantly affects performance.

This patch uses 32 bits transfer to simulate lower bits transfer,
and adjusts burst length runtimely to use biggeest burst length
as possible to reduce the gaps in transfer for PIO mode.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

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jiada wang 2017-08-10 13:50:08 +09:00 • committed by Mark Brown

parent ab2f357223

commit 1673c81d94

1 changed files with 141 additions and 9 deletions

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drivers/spi/spi-imx.c

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