dmaengine: hsu: Include headers we are direct user of

For the sake of integrity, include headers we are direct user of.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220713172235.22611-4-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: hsu: refactor hsu_dma_do_irq() to return int

Since we have nice macro IRQ_RETVAL() we would use it to convert a flag of
handled interrupt from int to irqreturn_t.

The rationale of doing this is:
a) hence we implicitly mark hsu_dma_do_irq() as an auxiliary function that
can't be used as interrupt handler directly, and
b) to be in align with serial driver which is using serial8250_handle_irq()
that returns plain int by design.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: hsu: refactor hsu_dma_do_irq() to return int

Since we have nice macro IRQ_RETVAL() we would use it to convert a flag of
handled interrupt from int to irqreturn_t.

The rationale of doing this is:
a) hence we implicitly mark hsu_dma_do_irq() as an auxiliary function that
can't be used as interrupt handler directly, and
b) to be in align with serial driver which is using serial8250_handle_irq()
that returns plain int by design.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dmaengine: hsu: Export hsu_dma_get_status()

To allow other code to safely read DMA Channel Status Register (where
the register attribute for Channel Error, Descriptor Time Out &
Descriptor Done fields are read-clear), export hsu_dma_get_status().
hsu_dma_irq() is renamed to hsu_dma_do_irq() and requires Status
Register value to be passed in.

Signed-off-by: Chuah, Kim Tatt <kim.tatt.chuah@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dmaengine: hsu: remove platform data

There are no platforms where it's not possible to calculate
the number of channels based on IO space length, and since
that is the only purpose for struct hsu_dma_platform_data,
removing it.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dmaengine: hsu: introduce stubs for the exported functions

This allows UART drivers to register HSU DMA Engine without
being forced to use ifdefs.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dmaengine: append hsu DMA driver

The HSU DMA is developed to support High Speed UART controllers found in
particular on Intel MID platforms such as Intel Medfield.

The existing implementation is tighten to the drivers/tty/serial/mfd.c driver
and has a lot of disadvantages. Besides that we would like to get rid of the
old HS UART driver in regarding to extending the 8250 which supports generic
DMAEngine API. That's why the current driver has been developed.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>