driver core: auxiliary bus: Add driver data helpers

Adds get/set driver data helpers for auxiliary devices.

Reviewed-by: Mark Gross <markgross@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: https://lore.kernel.org/r/20211208015015.891275-3-david.e.box@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/auxiliary_bus: Move the text into the code

The code and documentation are more difficult to maintain when kept
separately. This is further compounded when the standard structure
documentation infrastructure is not used.

Move the documentation into the code, use the standard documentation
infrastructure, add current documented functions, and reference the text
in the rst file.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20211202044305.4006853-8-ira.weiny@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/auxiliary_bus: Add example code for module_auxiliary_driver()

Add an example code snipit to the module_auxiliary_driver()
documentation which is consistent with the other example code in the
elsewhere in the documentation.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20211202044305.4006853-6-ira.weiny@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: auxiliary bus: minor coding style tweaks

For some reason, the original aux bus patch had some really long lines
in a few places, probably due to it being a very long-lived patch in
development by many different people. Fix that up so that the two files
all have the same length lines and function formatting styles.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Ertman <david.m.ertman@intel.com>
Cc: Fred Oh <fred.oh@linux.intel.com>
Cc: Kiran Patil <kiran.patil@intel.com>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: Martin Habets <mhabets@solarflare.com>
Cc: Parav Pandit <parav@mellanox.com>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Cc: Shiraz Saleem <shiraz.saleem@intel.com>
Link: https://lore.kernel.org/r/X8oiSFTpYHw1xE/o@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: auxiliary bus: make remove function return void

There's an effort to move the remove() callback in the driver core to
not return an int, as nothing can be done if this function fails. To
make that effort easier, make the aux bus remove function void to start
with so that no users have to be changed sometime in the future.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Ertman <david.m.ertman@intel.com>
Cc: Fred Oh <fred.oh@linux.intel.com>
Cc: Kiran Patil <kiran.patil@intel.com>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: Martin Habets <mhabets@solarflare.com>
Cc: Parav Pandit <parav@mellanox.com>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Cc: Shiraz Saleem <shiraz.saleem@intel.com>
Link: https://lore.kernel.org/r/X8ohB1ks1NK7kPop@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: auxiliary bus: move slab.h from include file

No need to include slab.h in include/linux/auxiliary_bus.h, as it is not
needed there. Move it to drivers/base/auxiliary.c instead.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Ertman <david.m.ertman@intel.com>
Cc: Fred Oh <fred.oh@linux.intel.com>
Cc: Kiran Patil <kiran.patil@intel.com>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: Martin Habets <mhabets@solarflare.com>
Cc: Parav Pandit <parav@mellanox.com>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Cc: Shiraz Saleem <shiraz.saleem@intel.com>
Link: https://lore.kernel.org/r/X8og8xi3WkoYXet9@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add auxiliary bus support

Add support for the Auxiliary Bus, auxiliary_device and auxiliary_driver.
It enables drivers to create an auxiliary_device and bind an
auxiliary_driver to it.

The bus supports probe/remove shutdown and suspend/resume callbacks.
Each auxiliary_device has a unique string based id; driver binds to
an auxiliary_device based on this id through the bus.

Co-developed-by: Kiran Patil <kiran.patil@intel.com>
Co-developed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Co-developed-by: Fred Oh <fred.oh@linux.intel.com>
Co-developed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Fred Oh <fred.oh@linux.intel.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Martin Habets <mhabets@solarflare.com>
Link: https://lore.kernel.org/r/20201113161859.1775473-2-david.m.ertman@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/160695681289.505290.8978295443574440604.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>