soundwire: SDCA: add helper macro to access controls

The upcoming SDCA (SoundWire Device Class Audio) specification defines
a hierarchical encoding to interface with Class-defined capabilities.

The specification is not yet accessible to the general public but this
information is released with explicit permission from the MIPI Board
to avoid delays with SDCA support on Linux platforms.

A block of 64 MBytes of register addresses are allocated to SDCA
controls, starting at address 0x40000000. The 26 LSBs which identify
individual controls are set based on the following variables:

- Function Number. An SCDA device can be split in up to 8 independent
Functions. Each of these Functions is described in the SDCA
specification, e.g. Smart Amplifier, Smart Microphone, Simple
Microphone, Jack codec, HID, etc.

- Entity Number. Within each Function, an Entity is an identifiable
block. Up to 127 Entities are connected in a pre-defined
graph (similar to USB), with Entity0 reserved for Function-level
configurations. In contrast to USB, the SDCA spec pre-defines
Function Types, topologies, and allowed options, i.e. the degree of
freedom is not unlimited to limit the possibility of errors in
descriptors leading to software quirks.

- Control Selector. Within each Entity, the SDCA specification defines
48 controls such as Mute, Gain, AGC, etc, and 16 implementation
defined ones. Some Control Selectors might be used for low-level
platform setup, and other exposed to applications and users. Note
that the same Control Selector capability, e.g. Latency control,
might be located at different offsets in different entities, the
Control Selector mapping is Entity-specific.

- Control Number. Some Control Selectors allow channel-specific values
to be set, with up to 64 channels allowed. This is mostly used for
volume control.

- Current/Next values. Some Control Selectors are
'Dual-Ranked'. Software may either update the Current value directly
for immediate effect. Alternatively, software may write into the
'Next' values and update the SoundWire 1.2 'Commit Groups' register
to copy 'Next' values into 'Current' ones in a synchronized
manner. This is different from bank switching which is typically
used to change the bus configuration only.

- MBQ. the Multi-Byte Quantity bit is used to provide atomic updates
when accessing more that one byte, for example a 16-bit volume
control would be updated consistently, the intermediate values
mixing old MSB with new LSB are not applied.

These 6 parameters are used to build a 32-bit address to access the
desired Controls. Because of address range, paging is required, but
the most often used parameter values are placed in the lower 16 bits
of the address. This helps to keep the paging registers constant while
updating Controls for a specific Device/Function.

Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20201103172226.4278-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

soundwire: registers: add definitions for clearable interrupt fields

DP0 has reserved fields and the read-only SDCA_CASCADE bit. We should
not try to write values in these fields, so add a formal definition
for clearable interrupts to be used in DP0 interrupt handling.

DPN also has reserved fields so add definitions for clearable
interrupts as well.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20201124013318.8963-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: remove SDW_REG_SHIFT()

soundwire had defined SDW_REG_SHIFT to calculate shift values for
bitmasks, but now that we have better things in bitfield.h, remove this.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-10-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: bus: initialize bus clock base and scale registers

The SoundWire 1.2 specification adds new registers to allow for
seamless clock changes while audio transfers are on-going. Program
them following the specification.

Note that dynamic clock changes are not supported for now, this only
adds the register initialization.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200608205436.2402-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: add definitions for 1.2 spec

Add definitions for register offsets and bit fields from the MIPI
SoundWire 1.2 specification (available to MIPI members at
https://members.mipi.org/wg/All-Members/document/download/78371)

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200608205436.2402-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: remove multiple blank lines

Multi-blank lines do not help readability so remove them

Checkpatch complains:
CHECK: Please don't use multiple blank lines

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

soundwire: fix SPDX license for header files

Some more headers had C++ style SDPX line, fix that and change copyright
so that it is consistent with rest of the code in subsystem

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

soundwire: Add SoundWire MIPI defined registers

MIPI SoundWire spec defines standard SoundWire registers mandatory for
SoundWire Slave devices, so add them.

Signed-off-by: Sanyog Kale <sanyog.r.kale@intel.com>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-By: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>