i2c: nomadik: support short xfer timeouts using waitqueue & hrtimer

Replace the completion by a waitqueue for synchronization from IRQ
handler to task. For short timeouts, use hrtimers, else use timers.
Usecase: avoid blocking the I2C bus for too long when an issue occurs.

The threshold picked is one jiffy: if timeout is below that, use
hrtimers. This threshold is NOT configurable.

Implement behavior but do NOT change fetching of timeout. This means the
timeout is unchanged (200ms) and the hrtimer case will never trigger.

A waitqueue is used because it supports both desired timeout approaches.
See wait_event_timeout() and wait_event_hrtimeout(). An atomic boolean
serves as synchronization condition.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>

0 files changed, 0 insertions, 0 deletions