The SoundWire bus code confuses bus and Slave device levels for
dev_err/dbg logs. That's not impacting functionality but the accuracy
of kernel logs.

We should only use bus->dev for bus-level operations and handling of
Device0. For all other logs where the device number is not zero, we
should use &slave->dev to provide more precisions to the
user/integrator.
Reported-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210122070634.12825-10-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Intel stress-tests routinely report IO timeouts and invalid power
management transitions. Upon further analysis, we seem to be using the
wrong devices in pm_runtime calls.

Before reading and writing registers, we first need to make sure the
Slave is fully resumed. The existing code attempts to do such that,
however because of a confusion dating from 2017 and copy/paste, we
end-up resuming the parent only instead of resuming the codec device.

This can lead to accesses to the Slave registers while the bus is
still being configured and the Slave not enumerated, and as a result
IO errors occur.

This is a classic problem, similar confusions happened for HDaudio
between bus and codec device, leading to power management issues.

Fix by using the relevant device for all uses of pm_runtime functions.

Fixes: 60ee9be2 ('soundwire: bus: add PM/no-PM versions of read/write functions')
Fixes: aa792935 ('soundwire: bus: fix io error when processing alert event')
Fixes: 9d715fa0 ('soundwire: Add IO transfer')
Reported-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210122070634.12825-9-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

sdw_write_no_pm and sdw_read_no_pm are useful when we want to do IO
without touching PM.

Fixes: 0231453b ('soundwire: bus: add clock stop helpers')
Fixes: 60ee9be2 ('soundwire: bus: add PM/no-PM versions of read/write functions')
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210122070634.12825-5-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

There is no need to play with pm_runtime reference counts, if needed
the codec drivers are already explicitly resumed.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210122070634.12825-4-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

When a Slave device is resumed, it may resume the bus and restart the
enumeration. During that process, we absolutely don't want to call
regular read/write routines which will wait for the resume to
complete, otherwise a deadlock occurs.

This patch fixes the same problem as the previous one, but is split to
make the life of linux-stable maintainers less painful.

Fixes: 29d158f9 ('soundwire: bus: initialize bus clock base and scale registers')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210122070634.12825-3-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

When a Slave device is resumed, it may resume the bus and restart the
enumeration. During that process, we absolutely don't want to call
regular read/write routines which will wait for the resume to
complete, otherwise a deadlock occurs.

Fixes: 60ee9be2 ('soundwire: bus: add PM/no-PM versions of read/write functions')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210122070634.12825-2-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

If there is no slave attached to soundwire bus, we
can return earlier from sdw_bus_prep_clk_stop() and
sdw_bus_exit_clk_stop(), this saves a redundant value
check.
Signed-off-by: Chao Song <chao.song@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-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/20210126085439.4349-1-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Add a dev_dbg() log for both enumeration and initialization completion
to better track suspend-resume issues.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Chao Song <chao.song@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210126085402.4264-1-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

The current error log does not provide details on the type of
transfers and which address/count was requested. All this information
can help locate in which parts of the configuration process an error
occurred.
Co-developed-by: Pierre-Louis Bossart <pierre-louis.bossart@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>
Link: https://lore.kernel.org/r/20210115053738.22630-4-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

We mix decimal and hexadecimal values, this leads to confusions in
dmesg logs and bug reports. Let's add a 0x prefix for all hexadecimal
values and a format when more than 4 bits are used.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210115053738.22630-2-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Mirror the changes made for DP0 and don't modify reserved fields.
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/20201124013318.8963-6-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

We should only access the fields that are relevant for DP0, and never
write to reserved or read-only SDCA_CASCADE fields.
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/20201124013318.8963-5-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

The code loops multiple times to deal with pending interrupts, but we
never reset the slave_notify status.
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/20201124013318.8963-3-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

The interrupt handling in SoundWire requires software to re-read the
interrupt status after clearing an interrupt. In case the interrupt is
still outstanding, the code in bus.c will loop a number of times,
however that loop is limited to the interrupts detected in the first
read. This strategy helps meet SoundWire requirements without
remaining forever in an interrupt handler.

Add a couple of comments to document this design.
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/20201124013318.8963-2-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

The SoundWire 1.2 specification defines an "SDCA cascade" bit which
handles a logical OR of all SDCA interrupt sources (up to 30 defined).

Due to limitations of the addressing space, this bit is located in the
SDW_DP0_INT register when DP0 is used, or alternatively in the
DP0_SDCA_Support_INTSTAT register when DP0 is not used.

To allow for both cases to be handled, this bit will be checked in the
main device-level interrupt handling code. This will result in the
register being read twice if DP0 is enabled, but it's not clear how to
optimize this case. It's also more logical to deal with this interrupt
at the device than the port level, this bit is really not DP0 specific
and its location in the DP0_INTSTAT bit is only due to the lack of
free space in SCP_INTSTAT_1.

The SDCA_Cascade bit cannot be masked or cleared, so the interrupt
handling only forwards the detection to the Slave driver, which will
deal with reading the relevant SDCA status bits and clearing them. The
bus driver only signals the detection.

The communication with the Slave driver is based on the same interrupt
callback, with only an extension to provide the status of the
sdca_cascade bit.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@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/20201104152358.9518-1-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Currently Slave devices are only added on startup, either from Device
Tree or ACPI entries. However Slave devices that are physically
present on the bus, but not described in platform firmware, will never
be added to the device list. The user/integrator can only know the
list of devices by looking a dynamic debug logs.

This patch suggests adding a Slave device even if there is no matching
DT or ACPI entry, so that we can see this in sysfs entry.

Initial code from Srinivas. Comments, fixes for ACPI probe and edits
of commit message by Pierre.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Co-developed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200924194430.121058-2-pierre-louis.bossart@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Test modes are required for all SoundWire IP, and help debug
integration issues. In theory each port can be configured with a
different mode but to simplify this patch only offers separate
configurations for the Master and Slave ports - this covers 99% of the
intended cases during platform integration.

The test mode value is set via platform-specific ways.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200920193207.31241-2-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

This algorithm computes bus parameters like clock frequency, frame
shape and port transport parameters based on active stream(s) running
on the bus.

Developers can also implement their own .compute_params() callback for
specific resource management algorithm, and set if before calling
sdw_add_bus_master()

Credits: this patch is based on an earlier internal contribution by
Vinod Koul, Sanyog Kale, Shreyas Nc and Hardik Shah. All hard-coded
values were removed from the initial contribution to use BIOS
information instead.
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200908131520.5712-1-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Provide prototype and export symbol to enable tests. The bus lock is
handled externally to avoid conflicts e.g. between kernel-generated
traffic and test traffic.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200908134521.6781-7-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

If a Slave device reports with a quirk that its initial parity check
may be incorrect, filter it but keep the parity checks active in
steady state.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200908134521.6781-5-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Some Slaves report incorrect information in their interrupt status
registers after a master/bus reset, track the initial interrupt
handling so that quirks can be introduced to filter out incorrect
information while keeping interrupts enabled in steady state.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200908134521.6781-4-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Unlike the traditional usage, in the SoundWire specification the
interrupt masks only gate the propagation of an interrupt condition to
the PING frame status. They do not gate the changes of the INT_STAT
registers, which will happen regardless of the mask settings. See
Figure 116 of the SoundWire 1.2 specification for an in-depth
description of the interrupt model.

When the bus driver reads the SCP_INT1_STAT register, it will retrieve
all the interrupt status, including for the mask fields that were not
explicitly set. For example, even if the PARITY mask is not set, the
PARITY error status will be reported if an implementation-defined
interrupt for jack detection is enabled and occurs.

Filtering undesired interrupt reports and handling has to be
implemented in software. This patch enables this filtering for the
INT1_IMPL_DEF, PARITY and BUS_CLASH interrupt sources.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200908134521.6781-3-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Add a slave-level property and program the SCP_INT1_MASK as desired by
the codec driver. Since there is no DisCo property this has to be an
implementation-specific firmware property or hard-coded in the driver.

The only functionality change is that implementation-defined
interrupts are no longer set for amplifiers - those interrupts are
typically for jack detection or acoustic event detection/hotwording.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200908134521.6781-2-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

use FIELD_GET() in bus code to extract field values instead of open
coding masks and shift operations.
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-3-vkoul@kernel.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

s/Instat/Intstat/
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/20200817220933.17492-1-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

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.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

We don't need to do anything for the slave if it is unattached during
clock stop prepare and exit sequences.
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200531151806.25951-1-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Expose MIPI DisCo Slave properties in sysfs.

For Slave properties and Data Port 0, the attributes are managed with
simple devm_ support.

A Slave Device may have more than one Data Port (DPN), and each Data
Port can be sink or source. The attributes are created dynamically
using pre-canned macros, but still use devm_ with a name attribute
group to avoid creating kobjects - as requested by GregKH. In the
_show function, we use container_of() to retrieve port number and
direction required to extract the information.

Audio modes are not supported for now. Depending on the discussions
the SoundWire Device Class, we may add it later as is or follow the
new specification.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200518203551.2053-4-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

In the existing SoundWire code, Master Devices are not explicitly
represented - only SoundWire Slave Devices are exposed (the use of
capital letters follows the SoundWire specification conventions).

With the existing code, the bus is handled without using a proper device,
and bus->dev typically points to a platform device. The right thing to
do as discussed in multiple reviews is use a device for each bus.

The sdw_master_device addition is done with minimal internal plumbing
and not exposed externally. The existing API based on
sdw_bus_master_add() and sdw_bus_master_delete() will deal with the
sdw_master_device life cycle, which minimizes changes to existing
drivers.

Note that the Intel code will be modified in follow-up patches (no
impact on any platform since the connection with ASoC is not supported
upstream so far).
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: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200518174322.31561-5-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Adding an unique id for each bus.
Suggested-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200518174322.31561-4-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

In preparation for future extensions, rename functions to use
sdw_bus_master prefix and add a parent and fwnode argument to
sdw_bus_master_add to help with device registration in follow-up
patches.

No functionality change, just renames and additional arguments.

The Intel code is currently unused, the two additional arguments are
only needed for compilation.
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: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200518174322.31561-2-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

No need for an "else" after a "return" statement. Remove multiple such
occurrences in bus.c.
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200508003046.23162-2-guennadi.liakhovetski@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

No need to repeat the same info log on all enumerations (essentially
each power-up), keep it as debug information.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200419185117.4233-4-yung-chuan.liao@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

It seems to be a typo. It makes more sense to return the return value
of sdw_update() instead of the value we want to update.
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200227220949.4013-1-pierre-louis.bossart@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Move bit extractors to macros, so that the definitions can be used by
other drivers parsing the MIPI definitions extracted from firmware
tables (ACPI or DT).
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200225170041.23644-4-pierre-louis.bossart@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

If a SoundWire link is enabled, but there are no Slave devices exposed
in firmware tables for this link, or no Slaves in ATTACHED or ALERT
mode, the CMD_IGNORED/-ENODATA error code on a broadcast write is
perfectly legit.

Filter this case to report errors and let the caller deal with the
CMD_IGNORED case.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200115000844.14695-11-pierre-louis.bossart@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

SoundWire supports two clock stop modes. Add support to handle the
clock stop modes and add pm_runtime calls in the bus.

Credits: this patch is based on an earlier internal contribution by
Vinod Koul, Sanyog Kale, Shreyas Nc and Hardik Shah.
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200115000844.14695-10-pierre-louis.bossart@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

There are two types of io errors when processing alert event.

a) the Master detects an ALERT status for e.g. a jack event and
invokes the implementation-defined function in the Slave driver to
check the jack status. At this time the codec is just suspended, so io
registers can't be accessed.

b) when waking up from clock stop mode1 state, where the bus needs a
complete re-enumeration, Slave registers can't be accessed until the
enumeration is complete.

This patch resumes the Slave device and waits for initialization
complete when processing slave alert event, so that registers on the
Slave can be accessed without timeouts or io errors.
Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200115000844.14695-9-pierre-louis.bossart@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Before removing the slave device, disable pm_runtime to prevent any
race condition with the resume being executed after the bus and slave
devices are removed.

Since this pm_runtime_disable() is handled in common routines,
implementations of Slave drivers do not need to call it in their
.remove() routine.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200115000844.14695-8-pierre-louis.bossart@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

When resuming with a bus reset, we need to re-enumerate and restart
from UNATTACHED. The helper added in this patch helps implement a more
robust state machine avoiding race conditions on resume.

The unattach request is stored and will be used by Slave drivers, if
needed: Intel validation exposed a corner case where the Slave device
may transition to D3 when streaming stops, but streaming restarts
before the Master transitions to D3. In that case, the Slave status
was not cleared as UNATTACHED by the Master resuming, and the
wait_for_completion will time out.

When the slave resumes, it can check if a Master-initiated
re-enumeration and initialization took place and skip the
wait_for_completion() if there is no reason to wait.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200115000844.14695-7-pierre-louis.bossart@linux.intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>