From: Oleksij Rempel <o.rempel@pengutronix.de>
Date: Tue, 10 Feb 2026 13:51:04 +0000 (+0100)
Subject: iio: dac: ds4424: use fsleep() instead of usleep_range()
X-Git-Tag: v7.1-rc1~17^2~120^2~21
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5ff37a60b39804c6e505fc2069a3d892b5d787f5;p=thirdparty%2Fkernel%2Fstable.git

iio: dac: ds4424: use fsleep() instead of usleep_range()

The DS4422/DS4424 and DS4402/DS4404 datasheets do not specify a minimum
delay between power-up (POR) and the availability of the I2C interface.

The driver previously used `usleep_range(1000, 1200)` to enforce a ~1ms
delay. Replace this with `fsleep(1000)` to allow the kernel to select
the most efficient sleep mechanism while retaining the existing
conservative delay to ensure device readiness.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---

diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c
index 3e72a40d053cc..f9cdc695032d7 100644
--- a/drivers/iio/dac/ds4424.c
+++ b/drivers/iio/dac/ds4424.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/regulator/consumer.h>
+#include <linux/time64.h>
 
 #include <linux/iio/driver.h>
 #include <linux/iio/iio.h>
@@ -244,7 +245,13 @@ static int ds4424_probe(struct i2c_client *client)
 		return ret;
 	}
 
-	usleep_range(1000, 1200);
+	/*
+	 * The datasheet does not specify a power-up to I2C ready time.
+	 * Maintain the existing conservative 1ms delay to ensure the
+	 * device is ready for communication.
+	 */
+	fsleep(1 * USEC_PER_MSEC);
+
 	ret = ds4424_verify_chip(indio_dev);
 	if (ret < 0)
 		goto fail;