[v2,0/2] spi: support inter-word delays

Message

Jonas Bonn Jan. 25, 2019, 12:24 p.m. UTC

Resubmission to fix thinko in spi-atmel patch.

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

 .../devicetree/bindings/spi/spi-bus.txt        |  1 +
 drivers/spi/spi-atmel.c                        | 18 +++++++++++++-----
 drivers/spi/spi.c                              |  4 ++++
 include/linux/spi/spi.h                        |  1 +
 4 files changed, 19 insertions(+), 5 deletions(-)