Messages in this thread | | | From | Maxime Chevallier <> | Subject | [PATCH 0/4] spi: a3700: Add improvements and full-duplex transfers | Date | Wed, 17 Jan 2018 17:15:24 +0100 |
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This patchset adds some improvements on the existing Armada 3700 SPI driver, the biggest being adding support for full-duplex transfers.
The first patch fixes an undocumented (to my knowledge, I might have missed something) behaviour where some of the content of the last write transfer is shifted out during a read half-duplex operation.
The second one sets the correct limits on the SPI max and min frequencies, based on the source clock rate.
The last 2 patches enable full-duplex transfers. On this controller, full-duplex transfers cannot use the hardware FIFOs and have to be performed either 1 or 4 bytes at a time. Because this is more CPU intensive, and a bit slower than FIFO mode, we only use the full-duplex way of transferring data when necessary.
Maxime Chevallier (4): spi: a3700: Clear DATA_OUT when performing a read spi: a3700: Set frequency limits at startup spi: a3700: Allow to enable or disable FIFO mode spi: a3700: Add full-duplex support
drivers/spi/spi-armada-3700.c | 106 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 91 insertions(+), 15 deletions(-)
-- 2.1.4
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