dmaengine: img-mdc-dma: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230919133207.1400430-18-u.kleine-koenig@pengutronix.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230718143138.1066177-1-robh@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: drivers: Use devm_platform_ioremap_resource()

platform_get_resource() and devm_ioremap_resource() are wrapped up in the
devm_platform_ioremap_resource() helper. Use the helper and get rid of the
local variable for struct resource *. We now have a function call less.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20221110152528.7821-1-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 422

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 101 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190113.822954939@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dmaengine: img-mdc-dma: Use vchan_terminate_vdesc() instead of desc_free

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

Implement the device_synchronize callback to make sure that the terminated
descriptor is freed.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: img-mdc: Add runtime PM

Add runtime PM support to disable the clock when the h/w is not in use.
The existing clock_prepare_enable is removed from probe() as the clock
is no longer permanently enabled.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: img-mdc: Add suspend / resume handling

Add suspend / resume handling using suspend_late and resume_early, and
check that all channels are idle before suspending.

DMA drivers should use suspend_late / resume_early to ensure that all
DMA client devices are suspended before the DMA device itself, and that
client devices are resumed after the DMA device. This avoids suspending
the DMA device while transactions are still active.

It is the responsibility of client drivers to terminate all DMA
transactions in their suspend handlers, so there should be no active
transactions by the time suspend_late is called.

There's no need to save and restore registers for MDC during suspend /
resume, as all transactions will be terminated as a result of the
suspend, and all required registers are programmed anyway at the start
of any new transactions following resume.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: img-mdc: remove unused ‘prev_phys’

In mdc_prep_dma_memcpy(), mdc_prep_dma_cyclic() and mdc_prep_slave_sg()
variable ‘prev_phys’ is initialized but never used, which
leads to warning with W=1

drivers/dma/img-mdc-dma.c: In function ‘mdc_prep_dma_memcpy’:
drivers/dma/img-mdc-dma.c:295:24: warning: variable ‘prev_phys’ set but not used [-Wunused-but-set-variable]
dma_addr_t curr_phys, prev_phys;

drivers/dma/img-mdc-dma.c: In function ‘mdc_prep_dma_cyclic’:
drivers/dma/img-mdc-dma.c:378:24: warning: variable ‘prev_phys’ set but not used [-Wunused-but-set-variable]
dma_addr_t curr_phys, prev_phys;

drivers/dma/img-mdc-dma.c: In function ‘mdc_prep_slave_sg’:
drivers/dma/img-mdc-dma.c:461:24: warning: variable ‘prev_phys’ set but not
used [-Wunused-but-set-variable]
dma_addr_t curr_phys, prev_phys;

So remove it.

Cc: Damien.Horsley <Damien.Horsley@imgtec.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: img-mdc: fix a possible NULL dereference

of_match_device could return NULL, and so cause a NULL pointer
dereference later at line 850:
mdma->soc = match->data;

For fixing this problem, we use of_device_get_match_data(), this will
simplify the code a little by using a standard function for
getting the match data.

This was reported by coverity (CID 1324134)

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: mdc: Correct terminate_all handling

Use of the CANCEL bit in mdc_terminate_all creates an
additional 'command done' to appear in the registers (in
addition to an interrupt).

In addition, there is a potential race between
mdc_terminate_all and the irq handler if a transfer
completes at the same time as the terminate all (presently
this results in an inappropriate warning).

To handle these issues, any outstanding 'command done'
events are cleared during mdc_terminate_all and the irq
handler takes no action when there are no new 'command done'
events.

Signed-off-by: Damien.Horsley <Damien.Horsley@imgtec.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: img-mdc: Remove unnecessary synchronize_irq() before devm_free_irq()

Calling synchronize_irq() right before devm_free_irq() is quite useless. On
one hand the IRQ can easily fire again before devm_free_irq() is entered,
on the other hand devm_free_irq() itself calls synchronize_irq() internally
(in a race condition free way), before any state associated with the IRQ is
freed.

Patch was generated using the following semantic patch:
// <smpl>
@@
expression irq, dev;
@@
-synchronize_irq(irq);
devm_free_irq(dev, irq, ...);
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: img-mdc: remove device_alloc_chan_resources handler

Now that device_alloc_chan_resources handler in not mandatory, remove dummy
implementations

Acked-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: Add driver for IMG MDC

Add support for the IMG Multi-threaded DMA Controller (MDC) found on
certain IMG SoCs. Currently this driver supports the variant present
on the MIPS-based Pistachio SoC.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>