diff options
author | Ira Weiny <ira.weiny@intel.com> | 2021-12-02 05:43:00 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-03 16:41:50 +0100 |
commit | 0d058a206adadf0c38f891b19dbdcb2963a1cd20 (patch) | |
tree | 5ef0c8c8f13f0019ffcbff8d8c4d55cea7ae5507 /Documentation/driver-api/auxiliary_bus.rst | |
parent | Documentation/auxiliary_bus: Clarify auxiliary_device creation (diff) | |
download | linux-0d058a206adadf0c38f891b19dbdcb2963a1cd20.tar.xz linux-0d058a206adadf0c38f891b19dbdcb2963a1cd20.zip |
Documentation/auxiliary_bus: Clarify match_name
Provide example code for how the match name is formed and where it is
supposed to be set.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20211202044305.4006853-3-ira.weiny@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/driver-api/auxiliary_bus.rst')
-rw-r--r-- | Documentation/driver-api/auxiliary_bus.rst | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/Documentation/driver-api/auxiliary_bus.rst b/Documentation/driver-api/auxiliary_bus.rst index 7dbb4f16462a..b041a72dc322 100644 --- a/Documentation/driver-api/auxiliary_bus.rst +++ b/Documentation/driver-api/auxiliary_bus.rst @@ -78,6 +78,9 @@ An auxiliary_device represents a part of its parent device's functionality. It is given a name that, combined with the registering drivers KBUILD_MODNAME, creates a match_name that is used for driver binding, and an id that combined with the match_name provide a unique name to register with the bus subsystem. +For example, a driver registering an auxiliary device is named 'foo_mod.ko' and +the subdevice is named 'foo_dev'. The match name is therefore +'foo_mod.foo_dev'. .. code-block:: c @@ -95,9 +98,9 @@ structure must be filled in as follows. The 'name' field is to be given a name that is recognized by the auxiliary driver. If two auxiliary_devices with the same match_name, eg -"mod.MY_DEVICE_NAME", are registered onto the bus, they must have unique id -values (e.g. "x" and "y") so that the registered devices names are "mod.foo.x" -and "mod.foo.y". If match_name + id are not unique, then the device_add fails +"foo_mod.foo_dev", are registered onto the bus, they must have unique id +values (e.g. "x" and "y") so that the registered devices names are "foo_mod.foo_dev.x" +and "foo_mod.foo_dev.y". If match_name + id are not unique, then the device_add fails and generates an error message. The auxiliary_device.dev.type.release or auxiliary_device.dev.release must be @@ -121,6 +124,10 @@ device to the bus. .. code-block:: c + #define MY_DEVICE_NAME "foo_dev" + + ... + struct auxiliary_device *my_aux_dev = my_aux_dev_alloc(xxx); /* Step 1: */ @@ -139,6 +146,9 @@ device to the bus. goto fail; } + ... + + Unregistering an auxiliary_device is a two-step process to mirror the register process. First call auxiliary_device_delete(), then call auxiliary_device_uninit(). @@ -205,6 +215,23 @@ Auxiliary drivers register themselves with the bus by calling auxiliary_driver_register(). The id_table contains the match_names of auxiliary devices that a driver can bind with. +.. code-block:: c + + static const struct auxiliary_device_id my_auxiliary_id_table[] = { + { .name = "foo_mod.foo_dev" }, + {}, + }; + + MODULE_DEVICE_TABLE(auxiliary, my_auxiliary_id_table); + + struct auxiliary_driver my_drv = { + .name = "myauxiliarydrv", + .id_table = my_auxiliary_id_table, + .probe = my_drv_probe, + .remove = my_drv_remove + }; + + Example Usage ============= |