[0/3] spi: s3c64xx: improve SPI polling mode

Message

Jaewon Kim April 4, 2023, 6 a.m. UTC

This patchset improves polling mode of s3c64xx driver.

s3cx64xx driver was supporing polling mode using quirk for SOC without DMA.
However there are situations in which spi polling mode should be
supported in some environments. To solve this situation, polling mode
can be used selectively by using device-tree as well as quirk.

When using the existing polling mode, the CPU utilization goes up to
100% becuase it checks register too frequently. In order to improve this
problem, IRQ is used by using the FIFO Trigger Level function.

Jaewon Kim (3):
  spi: s3c64xx: support spi polling mode using devicetree
  spi: dt-bindings: samsung: add samsung,spi-polling property
  spi: s3c64xx: support interrupt based pio mode

 .../devicetree/bindings/spi/samsung,spi.yaml  |  6 ++
 drivers/spi/spi-s3c64xx.c                     | 77 ++++++++++++++++---
 include/linux/platform_data/spi-s3c64xx.h     |  1 +
 3 files changed, 72 insertions(+), 12 deletions(-)