[v3,0/2] spi: support inter-word delays

Message

Jonas Bonn Jan. 26, 2019, 4:32 p.m. UTC

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 +++++++++++++-----
 include/linux/spi/spi.h |  3 +++
 2 files changed, 16 insertions(+), 5 deletions(-)