docs: cgroup-v2: fix misc.events key format descriptiongrafted

In misc cgroup, misc.events does not output a simple "max" key. Instead,
each registered misc resource outputs a separate key suffixed with ".max"
(i.e., "<res>.max").
Update the documentation to clarify that the entry key is "<res>.max".

Suggested-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Cheng Lingfei <chenglingfei@foxmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

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: