diff options
| author | Stepan Ionichev <sozdayvek@gmail.com> | 2026-05-11 10:30:43 +0500 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2026-05-31 10:59:38 +0100 |
| commit | a67d263922b7a4a8c30863ee4d8d20a482117f37 (patch) | |
| tree | ded78d278a55a6a90a2c9ce6ec5647f99d692842 /drivers | |
| parent | 8e9c394520844fb11404b4f9f16749f90e1d8627 (diff) | |
iio: adc: ad7793: replace usleep_range() with fsleep()
The AD7792/AD7793 datasheet (Rev. B, page 25, RESET section)
says: "When a reset is initiated, the user must allow a period
of 500 us before accessing any of the on-chip registers."
Use fsleep(500) instead of usleep_range(500, 2000). The 500 us
minimum stays the same; fsleep() picks the upper slack itself
(about +25% on a default config -- narrower than the original
2000 us).
Add a code comment with the datasheet reference so the "why"
of the wait is visible at the call site.
Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/iio/adc/ad7793.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c index 624530cce938..ea1c192e2142 100644 --- a/drivers/iio/adc/ad7793.c +++ b/drivers/iio/adc/ad7793.c @@ -268,7 +268,12 @@ static int ad7793_setup(struct iio_dev *indio_dev, ret = ad_sd_reset(&st->sd); if (ret < 0) goto out; - usleep_range(500, 2000); /* Wait for at least 500us */ + + /* + * Per AD7792/AD7793 datasheet (Rev. B, page 25, RESET section), + * allow 500 us after a reset before accessing on-chip registers. + */ + fsleep(500); /* write/read test for device presence */ ret = ad_sd_read_reg(&st->sd, AD7793_REG_ID, 1, &id); |