[lkml]   [2019]   [Jan]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Subject[PATCH v4 0/2] spi: support inter-word delays
Changed in v4:
* Rename word_delay to word_delay_us and slot it in _beside_ the
existing word_delay parameter in spi_transfer (see commit message for
more info).
* Add code to __spi_validate to make sure transfer and device align with
respect to the word_delay_us parameter

Changed in v3:
* Drop setting of inter-word delay via device tree

Changed in v2:
* Fix atmel-spi driver to not unconditionally set minimal delay if no
delay is required (erroneous clamping)

This short series adds support for SPI inter-word delays and configures
the spi-atmel driver to honour the setting.

Some SPI slaves are so slow that they are unable to keep up even at the
SPI controller's lowest available clock frequency. I have such a
configuration where an AVR-based SPI slave is unable to feed the SPI bus
fast enough even the SPI master runs at the lowest possible clock speed.

Jonas Bonn (2):
spi: support inter-word delay requirement for devices
spi-atmel: support inter-word delay

drivers/spi/spi-atmel.c | 18 +++++++++++++-----
drivers/spi/spi.c | 5 +++++
include/linux/spi/spi.h | 6 ++++++
3 files changed, 24 insertions(+), 5 deletions(-)


 \ /
  Last update: 2019-01-29 09:39    [W:0.133 / U:6.716 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site