dmaengine: idma64: 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/20230919133207.1400430-17-u.kleine-koenig@pengutronix.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idma64: Update bytes_transferred field

Currently when 8250 data transfer is done, bytes_tranferred always returns
0 at /sys/devices/pci0000\:\:**.*/dma/dma*chan*/bytes_transferred.
In many cases it gives false impression that data is not being
trasferred via DMA.

So, updating the bytes_transferred field to count the bytes
whenever there is data transfer using idma64.

Co-developed-by: Srikanth Thokala <srikanth.thokala@intel.com>
Signed-off-by: Srikanth Thokala <srikanth.thokala@intel.com>
Signed-off-by: Aman Kumar <aman.kumar@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230203121702.15725-1-aman.kumar@intel.com
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>

dmaengine: idma64: Make idma64_remove() return void

The function idma64_remove() returns zero unconditionally. Make it
return void.

This is a preparation for making platform remove callbacks return void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20221014161250.468687-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idma64: Switch to use __maybe_unused instead of ifdeffery

ifdeffery is prone to errors and makes code harder to read.
Switch to use __maybe_unused instead of ifdeffery.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20201104103131.89907-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

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

this program is free software you can redistribute it and or modify
it under the terms 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 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dmaengine: idma64: Move driver name to the header

There are two drivers that are relying on the iDMA 64-bit driver name
to match. Instead of duplicating string in both of them, dedicate
a header file and share it between users.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idma64: Use actual device for DMA transfers

Intel IOMMU, when enabled, tries to find the domain of the device,
assuming it's a PCI one, during DMA operations, such as mapping or
unmapping. Since we are splitting the actual PCI device to couple of
children via MFD framework (see drivers/mfd/intel-lpss.c for details),
the DMA device appears to be a platform one, and thus not an actual one
that performs DMA. In a such situation IOMMU can't find or allocate
a proper domain for its operations. As a result, all DMA operations are
failed.

In order to fix this, supply parent of the platform device
to the DMA engine framework and fix filter functions accordingly.

We may rely on the fact that parent is a real PCI device, because no
other configuration is present in the wild.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [for tty parts]
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idma: remove dma_slave_config direction usage

dma_slave_config direction was marked as deprecated quite some
time back, remove the usage from this driver so that the field
can be removed

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idma64: replace spin_lock_irqsave with spin_lock

idma64_chan_irq() is invoked in hardirq handle function, it is unnecessary
to call spin_lock_irqsave.

Signed-off-by: Zhaoxiong Yuan <yuanzhx326@gmail.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idma64: Support dmaengine_terminate_sync()

It appears that the driver misses the support of dmaengine_terminate_sync().
Since many of callers expects this behaviour implement the new
device_synchronize() callback to allow proper synchronization when stopping
a channel.

Fixes: b36f09c3c441 ("dmaengine: Add transfer termination synchronization support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idma64: simplify getting .drvdata

We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: idma64: clear LLP_[SD]_EN bits in last descriptor

The datasheet requires that the user must clear LLP_[SD]_EN bits whenever
LLP.LOC is zero, i.e. in the last descriptor of a multi-block chain.

Make the driver do this.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: idma64: use local variable to index descriptor

Since a local variable contains the number of hardware desriptors at the
beginning of idma64_desc_fill() we may use it to index the last descriptor as
well.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: idma64: convert idma64_hw_desc_fill() to return void

Explicitly show in idma64_desc_fill() how we link the hardware
descriptors.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: idma64: set maximum allowed segment size for DMA

This tells, for example, IOMMU what the maximum size of a segment
the DMA controller can send.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: idma64: drop IRQ enable / disable in handler

There is no need to disable interrupts in the IRQ handler. The driver
guarantess that at one time only one descriptor is active, besides the fact
that each call to the same channel will be serialized in idma64_chan_irq()
handler anyway.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: idma64: make better performance on pause / resume

Accordingly to the documentation the CH_DRAIN bit enforses single bursts when
channel is going to be suspended. This, in case when channel will be resumed,
makes data to flow in non-optimal mode until DMA returns to full burst mode.
The fix differentiates pause / resume cycle from pause / terminate and sets
CH_DRAIN bit accordingly.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: idma64: useless use of min_t()

We use a pattern

x = min_t(u32, <LOG2_CONSTANT>, __ffs(expr));

There is no need to use min_t() since we can replace it by

x = __ffs(expr | <2^LOG2_CONST>);

and moreover guarantee that argument of __ffs() will be not zero.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: idma64: convert to __ffs()

We replace __fls() by __ffs() since we have to find a *minimum* data width that
satisfies both source and destination.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: idma64: improve residue estimation

The residue calculation may provide a wrong estimation when the transfer is
started. There are possible scenarios we have to separate:

1) the transfer is not started yet; residue is equal to the total
length;

2) the transfer is just started (first chunk is ongoing); residue is
equal to the total length without already transfered bytes;

3) the transfer is ongoing and we already sent few chunks of data;
residue is equal to the total length without fully transfered chunks
and already sent bytes.

Mistakenly the calculation in cases 2) and 3) was done in the similar way and
the result is equal to -bytes that have been transfered, i.e. quite big since
size_t type can't keep negative values.

Rewrite the calculation algorithm to be one pass and have a correct result.

Besides above in case user asks for a status of the active DMA descriptor
without pausing an ongoing transfer the residue will be estimated based on the
register value, though it's still racy. Since the transfer is active the value
is continuously being changed. Here we have to read two registers at a time. To
minimize an error make those reads close to each other.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: add a driver for Intel integrated DMA 64-bit

Intel integrated DMA (iDMA) 64-bit is a specific IP that is used as a part of
LPSS devices such as HSUART or SPI. The iDMA IP is attached for private
usage on each host controller independently.

While it has similarities with Synopsys DesignWare DMA, the following
distinctions doesn't allow to use the existing driver:
- 64-bit mode with corresponding changes in Hardware Linked List data structure
- many slight differences in the channel registers

Moreover this driver is based on the DMA virtual channels framework that helps
to make the driver cleaner and easy to understand.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>