From: Stepan Ionichev Date: Mon, 11 May 2026 05:30:43 +0000 (+0500) Subject: iio: adc: ad7793: replace usleep_range() with fsleep() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a67d263922b7a4a8c30863ee4d8d20a482117f37;p=thirdparty%2Fkernel%2Flinux.git 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 Reviewed-by: Andy Shevchenko Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c index 624530cce9383..ea1c192e21421 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);