ata: pata_falcon: 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() will be 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>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

ata: pata_falcon: Stop using module_platform_driver_probe()

On today's platforms the benefit of platform_driver_probe() isn't that
relevant any more. It allows to drop some code after booting (or module
loading) for .probe() and discard the .remove() function completely if
the driver is built-in. This typically saves a few 100k.

The downside of platform_driver_probe() is that the driver cannot be
bound and unbound at runtime which is ancient and so slightly
complicates testing. There are also thoughts to deprecate
platform_driver_probe() because it adds some complexity in the driver
core for little gain. Also many drivers don't use it correctly. This
driver for example misses to mark the driver struct with __ref which is
needed to suppress a (W=1) modpost warning.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

ata: pata_falcon: add data_swab option to byte-swap disk data

Some users of pata_falcon on Q40 have IDE disks in default
IDE little endian byte order, whereas legacy disks use
host-native big-endian byte order as on the Atari Falcon.

Add module parameter 'data_swab' to allow connecting drives
with non-native data byte order. Drives selected by the
data_swap bit mask will have their user data byte-swapped to
host byte order, i.e. 'pata_falcon.data_swab=2' will byte-swap
all user data on drive B, leaving data on drive A in native
byte order. On Q40, drives on a second IDE interface may be
added to the bit mask as bits 2 and 3.

Default setting is no byte swapping, i.e. compatibility with
the native Falcon or Q40 operating system disk format.

Cc: William R Sowerbutts <will@sowerbutts.com>
Cc: Finn Thain <fthain@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: William R Sowerbutts <will@sowerbutts.com>
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

ata: pata_falcon: fix IO base selection for Q40

With commit 44b1fbc0f5f3 ("m68k/q40: Replace q40ide driver
with pata_falcon and falconide"), the Q40 IDE driver was
replaced by pata_falcon.c.

Both IO and memory resources were defined for the Q40 IDE
platform device, but definition of the IDE register addresses
was modeled after the Falcon case, both in use of the memory
resources and in including register shift and byte vs. word
offset in the address.

This was correct for the Falcon case, which does not apply
any address translation to the register addresses. In the
Q40 case, all of device base address, byte access offset
and register shift is included in the platform specific
ISA access translation (in asm/mm_io.h).

As a consequence, such address translation gets applied
twice, and register addresses are mangled.

Use the device base address from the platform IO resource
for Q40 (the IO address translation will then add the correct
ISA window base address and byte access offset), with register
shift 1. Use MMIO base address and register shift 2 as before
for Falcon.

Encode PIO_OFFSET into IO port addresses for all registers
for Q40 except the data transfer register. Encode the MMIO
offset there (pata_falcon_data_xfer() directly uses raw IO
with no address translation).

Reported-by: William R Sowerbutts <will@sowerbutts.com>
Closes: https://lore.kernel.org/r/CAMuHMdUU62jjunJh9cqSqHT87B0H0A4udOOPs=WN7WZKpcagVA@mail.gmail.com
Link: https://lore.kernel.org/r/CAMuHMdUU62jjunJh9cqSqHT87B0H0A4udOOPs=WN7WZKpcagVA@mail.gmail.com
Fixes: 44b1fbc0f5f3 ("m68k/q40: Replace q40ide driver with pata_falcon and falconide")
Cc: stable@vger.kernel.org
Cc: Finn Thain <fthain@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: William R Sowerbutts <will@sowerbutts.com>
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

ata: pata_falcon: Remove #include <asm/ide.h>

The Atari Falcon PATA driver does not need anything from <asm/ide.h>.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

scsi: ata: Declare SCSI host templates const

Make it explicit that ATA host templates are not modified.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com> (for DWC AHCI SATA)
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com> (for Tegra)
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230322195515.1267197-5-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

pata_falcon: Avoid type warnings from sparse

The zero day bot reported some sparse complaints in pata_falcon.c. E.g.

drivers/ata/pata_falcon.c:58:41: warning: cast removes address space '__iomem' of expression
drivers/ata/pata_falcon.c:58:41: warning: incorrect type in argument 1 (different address spaces)
drivers/ata/pata_falcon.c:58:41: expected unsigned short volatile [noderef] [usertype] __iomem *port
drivers/ata/pata_falcon.c:58:41: got unsigned short [usertype] *

The same thing shows up in 8 places, all told. Avoid this by removing
unnecessary type casts.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

scsi: ata: Use scsi_cmd_to_rq() instead of scsi_cmnd.request

Prepare for removal of the request pointer by using scsi_cmd_to_rq()
instead. This patch does not change any functionality.

Link: https://lore.kernel.org/r/20210809230355.8186-8-bvanassche@acm.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

m68k/q40: Replace q40ide driver with pata_falcon and falconide

This allows m68k q40 systems to switch from the deprecated IDE subsystem
to libata.

Enhance the byte-swapping falconide and pata_falcon platform drivers to
accept an irq resource, for use on q40. Atari ST-DMA IRQ arrangements seem
to co-exist with q40 IRQ arrangements without too much mess.

The new IO resources were added solely for the purpose of making
request_region() reservations identical to those made by q40ide: these
regions aren't used for actual IO.

Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Richard Zidlicky <rz@linux-m68k.org>
Reviewed-and-tested-by: Michael Schmitz <schmitzmic@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Link: https://lore.kernel.org/r/eefb7e9c2291e09fb4e065ce06bc105f05bb9e06.1623287706.git.fthain@linux-m68k.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

m68k/atari: Convert Falcon IDE drivers to platform drivers

Autoloading of Falcon IDE driver modules requires converting these
drivers to platform drivers.

Add platform device for Falcon IDE interface in Atari platform setup
code. Use this in the pata_falcon driver in place of the simple
platform device set up on the fly.

Convert falconide driver to use the same platform device that is used
by pata_falcon also. (With the introduction of a platform device for
the Atari Falcon IDE interface, the old Falcon IDE driver no longer
loads (resource already claimed by the platform device)).

Tested (as built-in driver) on my Atari Falcon.

Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://lore.kernel.org/r/1573008449-8226-1-git-send-email-schmitzmic@gmail.com
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

pata_falcon: clarify license version and use SPDX header

- clarify license version (it should be GPL 2.0)
- use SPDX header

Cc: Michael Schmitz <schmitzmic@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: add Atari Falcon PATA controller driver

Add Atari Falcon PATA controller driver. The major difference
when compared to legacy IDE's falconide host driver is that we
are using polled PIO mode and thus avoiding the need for STDMA
locking magic altogether.

Tested under ARAnyM emulator.

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>