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Documentation/auxiliary_bus: Clarify match_name

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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>
This commit is contained in:
Ira Weiny 2021-12-01 20:43:00 -08:00 committed by Greg Kroah-Hartman
parent b247703873
commit 0d058a206a
1 changed files with 30 additions and 3 deletions
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33
Documentation/driver-api/auxiliary_bus.rst
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@ -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
=============