6d2c66695b
Rather than a plain-vanilla init/exit, this patch provides 3 steps in the initialization needed for driver selection, machine driver selection and deal with power rail dependencies. - ACPI scan: this step is done at a very early stage to detect the presence of a SoundWire Controller and enabled links at the BIOS level. This step may be called from the legacy HDaudio driver, which will abort its probe to let the Sound Open Firmware (SOF) handle the hardware. - probe: this step allocates all the required memory and will add a sdw_bus, which in turn will result in identifying all possible Slaves listed below the Controller ACPI companion device. All the information is reported to the parent PCI driver which will select the relevant machine driver. - startup: this last step starts the bus reset, which results in Slave devices reporting as ATTACHED and being enumerated. This step is only done during the card creation stage, after the DSP is powered to account for internal power rail dependencies. These 3 steps are already supported in the Sound Open firmware drivers and upstream. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20200531182102.27840-7-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.