Initially, I started this patchset thinking: "we need a new delay for something-something" (in case someone is curios, we need a CS-hold-time for the first transfer, because the CS wakes a chip from sleep-mode). Then I added the delay, and felt a bit dirty-inside about adding a new one (just like that), and decided to look at maybe cleaning things up a bit, and a few days later, I got here. Full disclaimer: this patchset is not complete. It's an RFC. It's based on top of Jonathan's `iio/togreg` branch which also includes the ADIS driver library changes and also includes `cs_change_delay`. I'll send a V2 patchset, which just the first 4 patches, since I feel that those are a bit more complete. I thought about just sending the first 4 patches on-their-own, but I figured that the whole series (even if not complete) serves as a better explanation about the whole "why?". Hopefully, this can sort-of-explain things. I'll reference this RFC on the next series. Thanks Alexandru Ardelean (15): spi: move `cs_change_delay` backwards compat logic outside switch spi: introduce spi_delay struct as "value + unit" & spi_delay_exec() spi: make `cs_change_delay` the first user of the `spi_delay` logic iio: imu: adis: convert cs_change_delay to spi_delay struct spi: sprd: convert transfer word delay to spi_delay struct spi: orion: use new `word_delay` field for SPI transfers spi: spidev: use new `word_delay` field for spi transfers spi: core,atmel: convert `word_delay_usecs` -> `word_delay` for spi_device spi: introduce `delay` field for `spi_transfer` + spi_transfer_exec() spi: use new `spi_transfer_delay` helper where straightforward spi: tegra114: use `spi_transfer_delay` helper spi: spi-loopback-test: use new `delay` field spi: spidev: use new `delay` field for spi transfers spi: tegra114: change format for `spi_set_cs_timing()` function spi: implement SW control for CS times drivers/iio/imu/adis.c | 24 ++--- drivers/spi/spi-atmel.c | 29 +++++- drivers/spi/spi-bcm63xx-hsspi.c | 3 +- drivers/spi/spi-cavium.c | 3 +- drivers/spi/spi-fsl-dspi.c | 3 +- drivers/spi/spi-fsl-espi.c | 3 +- drivers/spi/spi-fsl-spi.c | 3 +- drivers/spi/spi-loopback-test.c | 12 ++- drivers/spi/spi-mpc512x-psc.c | 3 +- drivers/spi/spi-mpc52xx-psc.c | 3 +- drivers/spi/spi-omap-100k.c | 3 +- drivers/spi/spi-orion.c | 6 +- drivers/spi/spi-pl022.c | 25 +++-- drivers/spi/spi-sc18is602.c | 3 +- drivers/spi/spi-sh-hspi.c | 3 +- drivers/spi/spi-sprd.c | 11 ++- drivers/spi/spi-tegra114.c | 39 +++++--- drivers/spi/spi-tegra20-sflash.c | 2 +- drivers/spi/spi-topcliff-pch.c | 7 +- drivers/spi/spi-txx9.c | 3 +- drivers/spi/spi-xcomm.c | 3 +- drivers/spi/spi.c | 162 +++++++++++++++++++++++++------ drivers/spi/spidev.c | 6 +- include/linux/spi/spi.h | 65 ++++++++++--- 24 files changed, 293 insertions(+), 131 deletions(-) -- 2.20.1