iio: adc: ti_am335x_adc: Wait the idle state to avoid stalls

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At least on a am4372, a simple:
$ cat /sys/bus/iio/devices/iio\:deviceX/in_voltage*_raw
can stall forever. It seems that it comes from the fact that the
internal state machine does not have enough time to return to its idle
state in this situation before receiving another request, leading to an
internal stall.

Add a tiadc_wait_idle() helper to ensure no new conversion is requested
while the FSM is still busy.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-39-miquel.raynal@bootlin.com

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Miquel Raynal 2021-10-15 10:14:56 +02:00 • committed by Lee Jones

parent 90fc6ff48b

commit 8bed0166c6

1 changed files with 22 additions and 2 deletions

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drivers/iio/adc/ti_am335x_adc.c

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