iio: proximity: isl29501: Fix return type of isl29501_register_writegrafted

isl29501_register_write() was returning a u32 instead of an int.
Since the function returns negative error codes (such as -ERANGE or
return values from i2c_smbus_write_byte_data()), returning an unsigned
integer type prevents callers from correctly checking for negative error
conditions.

Fix this by changing the function return type from u32 to int.

This was found through manual code review.

Fixes: 1c28799257bc ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.")
Signed-off-by: Salah Triki <salah.triki@gmail.com>
Reviewed-by: Joshua Crofts <joshua.crofts1@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/Documentation/driver-api/devfreq.rst b/Documentation/driver-api/devfreq.rst
new file mode 100644
index 000000000..4a0bf87a3
--- /dev/null
+++ b/Documentation/driver-api/devfreq.rst
@@ -0,0 +1,30 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+========================
+Device Frequency Scaling
+========================
+
+Introduction
+------------
+
+This framework provides a standard kernel interface for Dynamic Voltage and
+Frequency Switching on arbitrary devices.
+
+It exposes controls for adjusting frequency through sysfs files which are
+similar to the cpufreq subsystem.
+
+Devices for which current usage can be measured can have their frequency
+automatically adjusted by governors.
+
+API
+---
+
+Device drivers need to initialize a :c:type:`devfreq_profile` and call the
+:c:func:`devfreq_add_device` function to create a :c:type:`devfreq` instance.
+
+.. kernel-doc:: include/linux/devfreq.h
+.. kernel-doc:: include/linux/devfreq-event.h
+.. kernel-doc:: drivers/devfreq/devfreq.c
+        :export:
+.. kernel-doc:: drivers/devfreq/devfreq-event.c
+        :export: