The runtime PM is always available on all Tegra SoCs since the commit
40b2bb1b ("ARM: tegra: enforce PM requirement"), so there is no
need to handle the case of unavailable RPM in the code anymore.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-11-digetx@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

There is no need to re-initialize the already initialized variables.
The tdc->config_init=false after driver's probe and after channel's
freeing, so there is no need to re-initialize it on the channel's
allocation.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-10-digetx@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

This patch fixes few dozens of coding style problems reported by
checkpatch and prettifies code where makes sense.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-9-digetx@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Use resource-managed variant of request_irq for brevity.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-8-digetx@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Use devm_platform_ioremap_resource to keep code cleaner a tad.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-7-digetx@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

There is no need to kill tasklet when driver's probe fails because tasklet
can't be scheduled at this time. It is also cleaner to kill tasklet on
channel's freeing rather than to kill it on driver's removal, otherwise
tasklet could perform a dummy execution after channel's releasing, which
isn't very nice.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-6-digetx@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

It's incorrect to check the channel's "busy" state without taking a lock.
That shouldn't cause any real troubles, nevertheless it's always better
not to have any race conditions in the code.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-5-digetx@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

The ISR tasklet could be kept scheduled after DMA transfer termination,
let's add synchronization hook which blocks until tasklet is finished.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-4-digetx@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Add basic interleaved support via EDMA.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200210094455.3615-1-peter.ujfalusi@ti.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Tasklets run with all the interrupts enabled. This means that we should
replace all the (already present) spin_lock_irqsave() uses in the tasklet
with spin_lock_irq() to protect being interrupted by a IRQ which tries
to get the same lock (via calls to device_prep_dma_* for example).

spin_lock and spin_lock_bh in tasklets are not enough to protect from IRQs,
update these to spin_lock_irq().

at_xdmac_advance_work() can be called with all the interrupts enabled (when
called from tasklet), or with interrupts disabled (when called from
at_xdmac_issue_pending). Move the locking in the callers to be able to use
spin_lock_irq() and spin_lock_irqsave() for these cases.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-10-tudor.ambarus@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

device_alloc_chan_resources can sleep, use GFP_KERNEL flag.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-9-tudor.ambarus@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

There is no need for locking in device_alloc_chan_resources(),
the DMA core takes care of it by using a dma_list_mutex around
the DMA devices.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-8-tudor.ambarus@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

The code in cause is already in the else case of
'if (at_xdmac_chan_is_cyclic(atchan))', drop the redundant check.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-7-tudor.ambarus@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Fix the following deadlocks:
1/ atc_handle_cyclic() and atc_chain_complete() called
dmaengine_desc_get_callback_invoke() while wrongly holding the
atchan->lock. Clients can set the callback to dmaengine_terminate_sync()
which will end up trying to get the same lock, thus a deadlock occurred.
2/ dma_run_dependencies() was called with the atchan->lock held, but the
method calls device_issue_pending() which tries to get the same lock,
and so a deadlock occurred.

The driver must not hold the lock when invoking the callback or when
running dependencies. Releasing the spinlock within a called function
before calling the callback is not a nice thing to do -> called functions
become non-atomic when called within an atomic region. Thus the lock is
now taken in the child routines whereever is needed.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-6-tudor.ambarus@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Avoids sleeping without depleting the emergency pool.
The rationale being that in most cases a dma device is either
offloading an operation that will automatically fallback to
software when the descriptor allocation fails, or we can simply poll
and wait for the dma device to release some in use descriptors.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-5-tudor.ambarus@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Probably a leftover, drop it.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-4-tudor.ambarus@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Having a list of descriptors allocated for the channel at
device_alloc_chan_resources() time is a sign for bad free usage.
Return err and add a debug message in case the channel is not
free from a previous use.

atchan->descs_allocated becomes useless, get rid of it. More,
drop the error message in atc_desc_get() because now it would
introduce an extra if statement. The callers of atc_desc_get()
already print error messages in case the callee fails, no one
is hurt.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-3-tudor.ambarus@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

There is no need for locking in device_alloc_chan_resources(),
the DMA core takes care of it by using a dma_list_mutex around
the DMA devices.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-2-tudor.ambarus@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

All members of the structure are initialized below in the function,
there is no need to use kzalloc.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-1-tudor.ambarus@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

In overlay application we noticed that dma channel node probe order is
inverted i.e s2mm channel is probed first followed by mm2s channel. The
reason for this inversion is fdtoverlay utility which uses a function
called fdt_add_subnode(*). It stores the subnodes after the properties,
this has the effect of inserting the new subnode before any others and
the end result is a reversal.

Because of this inverted channel probe order, the node probed first is
assigned a '0' index instead of Channel ID should be '0' for tx and '1'
for rx and dmatest client using the DT convention fails in dma transfer
as channel are swapped.

To fix above behavior and make channel assignment index independent
of probe order, always assign mm2s channel at '0' index and the s2mm
channel at IP specific fixed offset derived from the max_channels
count.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Link: https://lore.kernel.org/r/1580388865-9960-3-git-send-email-radhey.shyam.pandey@xilinx.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Extend dma_config structure to store the max channel count. This input is
used to populate dma device channel nodes at the fixed offset. It serves
as a preparatory patch for removing dma channel DT node order dependency,
added in the subsequent commit.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Link: https://lore.kernel.org/r/1580388865-9960-2-git-send-email-radhey.shyam.pandey@xilinx.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

To avoid race with vchan_complete, use the race free way to terminate
running transfer.

Move vdesc->node list_del in stm32_dma_start_transfer instead of in
stm32_mdma_chan_complete to avoid another race in vchan_dma_desc_free_list.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-9-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

This patch fixes BUG: sleeping function called from invalid context in
stm32_dma_disable_chan function.

The goal of this function is to force channel disable if it has not been
disabled by hardware. This consists in clearing STM32_DMA_SCR_EN bit and
read it as 0 to ensure the channel is well disabled and the last transfer
is over.

In previous implementation, the waiting loop was based on a do...while (1)
with a call to cond_resched to give the scheduler a chance to run a higher
priority process.

But in some conditions, stm32_dma_disable_chan can be called while
preemption is disabled, on a stm32_dma_stop call for example. So
cond_resched must not be used.

To avoid this, use readl_relaxed_poll_timeout_atomic to poll
STM32_DMA_SCR_EN bit cleared.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-8-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

This patch adds copy_align property in accordance with hardware
restriction.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-7-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

This patch adds dma_set_max_seg_size to define sg dma constraint.
This constraint may be taken into account by client to scatter/gather
its buffer.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-6-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Enable client to resubmit already processed descriptors
in order to save descriptor creation time.
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-5-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Change STM32 DMA driver to defer its probe operation when reset
controller is expected but has not been probed yet when DMA
device is probed.

Changes error traces when failing to get a system resource so that
it is not printed on failure with deferred probing.
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-4-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Remove reset controller reference from device instance since it is
used only at probe time.
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-3-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Add suspend/resume power management relying on PM Runtime engine.
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200129153628.29329-2-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Reset DMA channel after stop to ensure that pending transfers and FIFOs
in the datapath are flushed or completed. It also cleanup the terminate
path and removes stop for the cyclic mode as after the reset stop is not
required. This fixes intermittent data verification failure when xilinx
dma test the client is stressed and loaded/unloaded multiple times.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Link: https://lore.kernel.org/r/1580283909-32678-1-git-send-email-radhey.shyam.pandey@xilinx.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Changes STM32 DMAMUX driver to defer its probe operation when
reset controller is expected but has not been probed yet.

Changes error traces when failing to get a system resource so that
it is not printed on failure with deferred probing.
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200128094158.20361-5-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Remove reset controller reference from device instance since it is
used only at probe time.
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200128094158.20361-4-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

This change ensures the DMAMUX device is reset only once it is clocked
and that clock is released in a safe state when probe operation fails.
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200128094158.20361-3-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Add suspend/resume power management relying on PM Runtime engine.
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200128094158.20361-2-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

To avoid race with vchan_complete, use the race free way to terminate
running transfer.

Move vdesc->node list_del in stm32_mdma_start_transfer instead of in
stm32_mdma_xfer_end to avoid another race in vchan_dma_desc_free_list.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200127085334.13163-7-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Enable descriptor reuse to allow client to resubmit already processed
descriptors in order to save descriptor creation time.
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200127085334.13163-6-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

This patch changes error log when failing to get the clock so that it is
not printed on failure with probe deferring.

It also defers probe when reset controller is expected but has not been
probed yet when MDMA device is probed.
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200127085334.13163-5-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

This patch disables the clock in case of error during probe. The unneeded
err_unregister label is renamed err_clk instead.
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200127085334.13163-4-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Remove reset controller reference from device instance since it is
used only at probe time.
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200127085334.13163-3-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Add suspend/resume power management relying on PM Runtime engine.
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Link: https://lore.kernel.org/r/20200127085334.13163-2-amelie.delaunay@st.comSigned-off-by: Vinod Koul <vkoul@kernel.org>