Adds support for a low-power Hibernation State.
Add support for a low-power hibernation state for the DSP. In
this state the DSP RAM contents are maintained, such that
firmware does not need to be re-downloaded, but the rest of the
chip's register state is lost.
Entry to this state is achieved via the register interface
(either by an external driver using the control port, or the
programmable DSP). Exit from this state is triggered by activity
on device GPIO pins, intended SPI transaction, or I2C
transaction with intended slave address.
Signed-off-by: Vlad Karpovich <vkarpovi@opensource.cirrus.com>
Link: https://lore.kernel.org/r/167933511185.26.10641185496218226278@mailman-core.alsa-project.orgSigned-off-by: Mark Brown <broonie@kernel.org>