firmware: revamp firmware documentation
Understanding this code is getting out of control without any
notes. Give the firmware_class driver a much needed documentation love,
and while at it convert it to the new sphinx documentation format.
v2: typos and small fixes
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/Documentation/driver-api/firmware/lookup-order.rst b/Documentation/driver-api/firmware/lookup-order.rst
new file mode 100644
index 0000000..88c8173
--- /dev/null
+++ b/Documentation/driver-api/firmware/lookup-order.rst
@@ -0,0 +1,18 @@
+=====================
+Firmware lookup order
+=====================
+
+Different functionality is available to enable firmware to be found.
+Below is chronological order of how firmware will be looked for once
+a driver issues a firmware API call.
+
+* The ''Built-in firmware'' is checked first, if the firmware is present we
+ return it immediately
+* The ''Firmware cache'' is looked at next. If the firmware is found we
+ return it immediately
+* The ''Direct filesystem lookup'' is performed next, if found we
+ return it immediately
+* If no firmware has been found and the fallback mechanism was enabled
+ the sysfs interface is created. After this either a kobject uevent
+ is issued or the custom firmware loading is relied upon for firmware
+ loading up to the timeout value.
