dma_request_slave_channel() returns NULL on error and not ERR_PTRs.
I've fixed this by using dma_request_slave_channel_reason() which does
return ERR_PTRs.

Fixes: a915d150 ('spi: tegra: convert to standard DMA DT bindings')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

Tegra124 adds a number of extra modules into the configlink bus, which
must be taken out of reset before the bus is used. Update the AHUB
driver to know about these extra modules (the AHUB HW module hosts the
configlink bus).
Based-on-work-by: Arun Shamanna Lakshmi <aruns@nvidia.com>
Based-on-work-by: Songhee Baek <sbaek@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Brown <broonie@linaro.org>
---
This patch depends on "ASoC: tegra: use reset framework" to compile,
which is ack'd and slated to go through a (large) topic branch in the
Tegra tree. So, we can either:

a) Merge that Tegra topic branch into the ASoC tree, then apply this.
   Note that I haven't created the topic branch yet, since I'm still
   waiting for DMA dependencies to be applied.

b) Apply this change to the Tegra tree too. This change isn't directly
   related to the changes in the Tegra tree; it just makes use of the new
   reset controller feature that's introduced there.

The "pcie_xclk" clock is not actually a clock at all, but rather a reset
domain. Now that the custom Tegra module reset API has been removed, we
can remove the definition of any "clocks" that existed solely to support
it.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>

Now that no code uses the custom Tegra module reset API, we can remove
its implementation.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>

Now that all Tegra drivers have been converted to use DMA APIs which
retrieve DMA channel information from standard DMA DT properties, we can
remove all the legacy DT DMA-related properties.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>

Now that all Tegra drivers have been converted to use the common reset
framework, we can remove all the legacy DT clocks/clock-names entries for
"clocks" that were only used with the old custom Tegra module reset API.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thierry Reding <treding@nvidia.com>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>

By using dma_request_slave_channel_or_err(), the DMA slave ID can be
looked up from standard DT properties, and squirrelled away during
channel allocation. Hence, there's no need to use a custom DT property
to store the slave ID.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thierry Reding <treding@nvidia.com>

By using dma_request_slave_channel_or_err(), the DMA slave ID can be
looked up from standard DT properties, and squirrelled away during
channel allocation. Hence, there's no need to use a custom DT property
to store the slave ID.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Brown <broonie@linaro.org>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Brown <broonie@linaro.org>
Reviewed-by: Thierry Reding <treding@nvidia.com>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Marc Dietrich <marvin24@gmx.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Thierry Reding <treding@nvidia.com>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Thierry Reding <treding@nvidia.com>

By passing no flags when calling snd_dmaengine_pcm_register() from
tegra_pcm.c, we end up using dma_request_slave_channel() rather than
dmaengine_pcm_compat_request_channel(), and hence rely on the standard
DMA DT bindings and stashing the DMA slave ID away during channel
allocation. This means there's no need to use a custom DT property to
store the slave ID. So, remove all the code that parsed it.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Brown <broonie@linaro.org>

The Tegra30 I2S driver currently allocates DMA FIFOs from the AHUB only
when an audio stream starts playback. This is theoretically nice for
resource sharing, but makes no practical difference for any configuration
the drivers currently support. However, this deferral prevents conversion
to the standard DMA DT bindings, since conversion requires knowledge of
the specific DMA channel to be allocated, which in turn depends on which
specific FIFO was allocated.

For this reason, move the FIFO allocation into probe() to allow later
conversion to the standard DMA DT bindings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Brown <broonie@linaro.org>

Call pm_runtime_get_sync() before all register accesses; the HW requires
clocks to be running when accessing registers.

This hasn't been needed to date, since all register IO was performed
while playback was active, and hence the ASoC core had already called
pm_runtime_get(). However, an imminent future commit will allocate and
set up the FIFOs and routing during probe(), when that "protection"
won't be in place.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Brown <broonie@linaro.org>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.

This change also renames "clock"/"clk" to "modules"/"mod" in symbols
related to entries in configlink_clocks[], since:
- We don't care about clock handles any more, but rather reset handles,
  so the old name isn't applicable.
- It really is a list of modules on the bus, about which we currently
  only care about reset handles.
If we start caring about any other aspect of the modules in the future,
we won't have to rename all these symbols again.

Note: The addition of "depends COMMON_CLOCK" is something that was missing
before, not a new requirement.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Brown <broonie@linaro.org>
Reviewed-by: Thierry Reding <treding@nvidia.com>

Call of_dma_controller_register() so that DMA clients can look up the
Tegra DMA controller using standard APIs. This requires the of_xlate()
function to save off the DMA slave ID, and for tegra_dma_slave_config()
not to over-write this information; once DMA client drivers are converted
to dma_request_slave_channel() and DT-based lookups, they won't set this
field of struct dma_slave_config anymore.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Thierry Reding <treding@nvidia.com>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-By: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-By: Terje Bergstrom <tbergstrom@nvidia.com>

Tegra's clock driver now provides an implementation of the common
reset API (include/linux/reset.h). Use this instead of the old Tegra-
specific API; that will soon be removed.

The old Tegra-specific API used a struct clock to represent the module
to reset. Some of the clocks retrieved during probe() were only used for
reset purposes, and indeed aren't even true clocks. So, there's no need
to get() them any more.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>

The Tegra CAR module implements both a clock and reset controller. So
far, the driver exposes the clock feature via the common clock API and
the reset feature using a custom API. This patch adds an implementation
of the common reset framework API (include/linux/reset*.h). The legacy
reset implementation will be removed once all drivers have been
converted.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>

The Tegra clock driver is built unconditionally when Tegra support is
enabled. In order to avoid having to ifdef the forthcoming reset driver
implementation, have ARCH_TEGRA select RESET_CONTROLLER.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>

This patch switches the Tegra DT files to use the standard DMA DT bindings
rather than custom properties. Note that the legacy properties are not yet
removed; the drivers must be updated to use the new properties first.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>

An earlier patch updated the Tegra DT bindings to require resets and
reset-names properties to be filled in. This patch updates the DT files
to include those properties.

Note that any legacy clocks and clock-names entries that are replaced by
reset properties are not yet removed; the drivers must be updated to use
the new resets and reset-names properties first.
Signed-off-by: Stephen Warren <swarren@nvidia.com>

Update all the Tegra DT bindings to require the standard dmas/dma-names
properties rather than non-standard nvidia,dma-request-selector property.

This is a DT-ABI-incompatible change. It is the second of two changes
required for me to consider the Tegra DT bindings as stable, the other
being the previous conversion to the common reset bindings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>

Update all the Tegra DT bindings to require resets/reset-names properties
where the HW module has reset inputs. Remove any entries from clocks or
clock-names that were only required to identify reset inputs, rather than
referring to real clocks.

This is a DT-ABI-incompatible change. It is the first of two changes
required for me to consider the Tegra DT bindings as stable, the other
being conversion to the common DMA DT bindings.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-By: Terje Bergstrom <tbergstrom@nvidia.com>

Many of the Tegra DT binding documents say nothing about the clocks or
clock-names properties, yet those are present and required in DT files.
This patch simply updates the documentation file to match the implicit
definition of the binding, based on real-world DT content.

All Tegra bindings that mention clocks are updated to have consistent
wording and formatting of the clock-related properties.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-By: Terje Bergstrom <tbergstrom@nvidia.com>

Tegra clk branch for 3.14

ASoC: dma: Generic ASoC dmaengine driver enhancements

This is the work so far on dmaengine for v3.14, it is being cross merged
into the Tegra tree to support a large DMA overhaul there.  The main
additions are a change in the DMA request API which allows better
interaction at system startup using deferred probes and methods for
overriding the default device and channel names used to request DMA.

This merges git://git.infradead.org/users/vkoul/slave-dma.git topic/of

This merges git://git.infradead.org/users/vkoul/slave-dma.git topic/defer_probe

Check the return value of dma_request_slave_channel_reason() to see if
deferred probe happens, not the variable the return value will be
assigned to later.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 5eda87b8 ("ASoC: dmaengine: support deferred probe for DMA channels")
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Enhance dmaengine_pcm_request_chan_of() to support deferred probe for
DMA channels, by using the new dma_request_slave_channel_or_err() API.
This prevents snd_dmaengine_pcm_register() from succeeding without
acquiring DMA channels due to the relevant DMA controller not yet being
registered.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

The following branch/patch is a dependency for my "ASoC: dmaengine:
support deferred probe for DMA channels". If you could pull the branch
below into your topic/dma, then merge my ASoC patch, that would be
great. I would then like to merge your topic/dma into the Tegra tree as
a baseline for the Tegra conversion to the standard DMA DT bindings.

Vinod has confirmed this his topic/defer_probe branch is stable, and
won't be rebased:

https://lkml.org/lkml/2013/12/10/463

mmp_pdma.c implements a custom of_xlate() function that is 95% identical
to what Tegra will need. Create a function to implement the common part,
so everyone doesn't just cut/paste the implementation.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: dmaengine@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dma_request_slave_channel() simply returns NULL whenever DMA channel
lookup fails. Lookup could fail for two distinct reasons:

a) No DMA specification exists for the channel name.
   This includes situations where no DMA specifications exist at all, or
   other general lookup problems.

b) A DMA specification does exist, yet the driver for that channel is not
   yet registered.

Case (b) should trigger deferred probe in client drivers. However, since
they have no way to differentiate the two situations, it cannot.

Implement new function dma_request_slave_channel_reason(), which performs
identically to dma_request_slave_channel(), except that it returns an
error-pointer rather than NULL, which allows callers to detect when
deferred probe should occur.

Eventually, all drivers should be converted to this new API, the old API
removed, and the new API renamed to the more desirable name. This patch
doesn't convert the existing API and all drivers in one go, since some
drivers call dma_request_slave_channel() then dma_request_channel() if
that fails. That would require either modifying dma_request_channel() in
the same way, or adding extra error-handling code to all affected
drivers, and there are close to 100 drivers using the other API, rather
than just the 15-20 or so that use dma_request_slave_channel(), which
might be tenable in a single patch.

acpi_dma_request_slave_chan_by_name() doesn't currently implement
deferred probe. It should, but this will be addressed later.
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Add fields to struct snd_dmaengine_pcm_config to allow custom:

- DMA channel names.

  This is useful when the default "tx" and "rx" channel names don't
  apply, for example if a HW module supports multiple channels, each
  having different DMA channel names. This is the case with the FIFOs
  in Tegra's AHUB. This new facility can replace
  SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME.

- DMA device

  This allows requesting DMA channels for a device other than the device
  which is registering the "PCM" driver. This is quite unusual, but is
  currently useful on Tegra. In much HW, and in Tegra20, each DAI HW
  module contains its own FIFOs which DMA writes to. However, in Tegra30,
  the DMA FIFOs were split out AHUB HW module, which then routes the data
  through a cross-bar, and into the DAI HW modules. However, the current
  ASoC driver structure does not expose this detail, and acts as if the
  FIFOs are still part of the DAI HW modules. Consequently, the "PCM"
  driver is registered with the DAI HW module, yet the DMA channels must
  be looked up in the AHUB HW module's device tree node. This new config
  field allows that to happen. Eventually, the Tegra drivers will be
  reworked to fully expose the AHUB, and this config field can be
  removed.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>