staging: fbtft: 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 (mostly) ignored
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.

The function fbtft_driver_remove_pdev() (that exists several times as it's
part of a macro expansion) returns zero unconditionally, so it can be
trivially converted to return void without semantic changes.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231026214407.2508590-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Constify buf parameter in fbtft_dbg_hex()

It's obvious that we don't and shouldn't modify buffer that
is about to be dumped. Constify parameter in fbtft_dbg_hex()
to make it clear.

Fixes: c296d5f9957c ("staging: fbtft: core support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220316165351.58107-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Deduplicate driver registration macros

The two macros FBTFT_REGISTER_DRIVER and FBTFT_REGISTER_SPI_DRIVER
contain quite some duplication: Both define an spi driver and an of device
table and the differences are quite subtle.

So create two new macros and use both twice.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220118181338.207943-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spi: make remove callback a void function

The value returned by an spi driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Claudius Heine <ch@denx.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

staging: fbtft: Deduplicate driver registration macros

The two macros FBTFT_REGISTER_DRIVER and FBTFT_REGISTER_SPI_DRIVER
contain quite some duplication: Both define an spi driver and an of device
table and the differences are quite subtle.

So create two new macros and use both twice.

Link: https://lore.kernel.org/r/20220118181338.207943-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

staging: fbtft: Fix error path in fbtft_driver_module_init()

If registering the platform driver fails, the function must not return
without undoing the spi driver registration first.

Fixes: c296d5f9957c ("staging: fbtft: core support")
Link: https://lore.kernel.org/r/20220118181338.207943-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

staging: fbtft: Fix error path in fbtft_driver_module_init()

If registering the platform driver fails, the function must not return
without undoing the spi driver registration first.

Fixes: c296d5f9957c ("staging: fbtft: core support")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220118181338.207943-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: add macro FBTFT_REGISTER_SPI_DRIVER

After 5fa6863ba692 ("spi: Check we have a spi_device_id for each DT
compatible") we need to add spi id_tables. Changing existing macro
FBTFT_REGISTER_DRIVER would have meant to change arguments and
therefore adjust all fbtft drivers.

This patch adds a new and simplified macro FBTFT_REGISTER_SPI_DRIVER
that includes a spi id_table, and in addition to that:
- does not define a platform driver
- uses macro module_spi_driver()

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/a58b3bc9-27a2-3f16-dd92-e597666a0263@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Make fbtft_remove_common() return void

fbtft_remove_common() is only called with a non-NULL fb_info. (All
callers are in remove callbacks and the matching probe callbacks set
driver data accordingly.) So fbtft_remove_common() always returns zero.
Make it return void instead which makes it easier to see in the callers
that there is no error to handle.

Also the return value of platform and spi remove callbacks is ignored
anyway and not freeing resources in .remove() is a bad idea.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20211012153945.2651412-20-u.kleine-koenig@pengutronix.de
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Avoid potential precedence issues

Put parentheses around uses of macro parameters to avoid possible
precedence issues. Problem detected by checkpatch.

Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Link: https://lore.kernel.org/r/5c8520a5c3da453460608deee9a25232d52f4513.1584314604.git.mh12gx2825@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Reformat long macro definitions

Multiple macro definitions crossing 80 character line length makes them
hard to understand. Reformatting the these lines makes the code more
readable and easier to understand. Issue flagged by checkpatch script.

Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/b8d2fc0f55339830694ee51860cc970ce1b9cae4.1584314604.git.mh12gx2825@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbtft: Drop OF dependency

Now, since driver became OF independent, no need to keep OF dependency.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20191120095716.26628-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: fixed format-string errors.

Added __printf attribute to declaration of fbtft_dbg_hex and fixed
mismatches between format-specifiers and arguments in several function
calls.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Staging: fbtft: Switch to the gpio descriptor interface

This switches the fbtft driver to use GPIO descriptors
rather than numerical gpios:

Utilize the GPIO library's intrinsic handling of OF GPIOs
and polarity. If the line is flagged active low, gpiolib
will deal with this.

Remove gpios from platform device structure. Neither assign
statically numbers to gpios in platform device nor allow
gpios to be parsed as module parameters.

Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Prefer using the BIT macro

Replacing all occurrences of (1<<x) with BIT(x) to fix checkpatch issue.
CHECK:Prefer using the BIT macro

Signed-off-by: Mamta Shukla <mamtashukla555@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Adds space around "/"

Kernel coding style recommends a space char around "/".

Signed-off-by: Leonardo Brás <leobras.c@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Fixes some alignment issues - Style

Fixes (most) alignment issues pointed by checkpatch.pl.

Signed-off-by: Leonardo Brás <leobras.c@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Puts macro arguments in parenthesis to avoid precedence issues - Style

Puts macro arguments in parenthesis to avoid precedence issues.
Some large lines were broken to fit the 80-char limit.

Signed-off-by: Leonardo Brás <leobras.c@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Stop using BL_CORE_DRIVER1

Leaking driver internal tracking into the already massively confusing
backlight power tracking is really confusing.

Luckily we have already a drvdata structure, so fixing this is really
easy.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

staging: fbtft: remove redundant license text

Now that the SPDX tag is in all fbtft files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: add SPDX identifiers

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Fix up the all of the staging fbtft drivers to have a proper SPDX
identifier, based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: add helper fbtft_write_buf_dc

Factor out setting DC GPIO and writing buffer content to helper
fbtft_write_buf_dc.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Make the pointers to s16 init arrays const

This allows making some of the actual arrays const.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: change 'gamma' array to u32

Having a local variable of 1024 bytes on 64-bit architectures is a bit
too much, and I ran into this warning while trying to see what functions
use the largest stack:

drivers/staging/fbtft/fbtft-sysfs.c: In function 'store_gamma_curve':
drivers/staging/fbtft/fbtft-sysfs.c:132:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

As there is no need for 64-bit gamma values (on 32-bit architectures,
we don't use those either), I'm changing the type from 'unsigned long'
to 'u32' here, which cuts the required space in half everywhere.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: remove custom DMA mapped buffer

There is no need to duplicate what SPI core already does, i.e. mapping buffers
for DMA capable transfers.

Remove all related pices of code.

Note, that code, besides its redundancy, was buggy: DMA address potentially can
be 0, SPI slave device has nothing to do with DMA capable device properties and
DMA mask in particular.

Suggested-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Convert int arrays to s16

These arrays use -1, -2, and -3 as initiators for various types of
writes to initialize hardware.

No values are used that conflict with using these arrays as s16
instead of int and reducing overall data is good.

$ size drivers/staging/fbtft/built-in.o*
text data bss dec hex filename
116120 32872 4152 153144 25638 drivers/staging/fbtft/built-in.o.new
116104 36344 6200 158648 26bb8 drivers/staging/fbtft/built-in.o.old

Miscellaneous:

o Realign some of the arrays to make reading a bit easier

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Staging: fbtft: fixed unsigned type warnings

Replace unsigned by unsigned int in fbtft driver. Issue found by
checkpatch.

Signed-off-by: Ming Yang <minos.future@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Remove unused and duplicated defines

This patch makes use of the standard MIPI Display Command Set to remove
some of duplicate defines from the headers.

Signed-off-by: Priit Laes <plaes@plaes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

spi: Drop owner assignment from spi_drivers

An spi_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

Staging: fbtbt: Replace timespec with ktime_t

struct timespec will overflow in year 2038, so replace it with
ktime_t. And replace functions that use struct timespec,
timespec_sub with ktime_sub. Also use monotonic time instead of real
time, by replacing getnstimeofday with ktime_get, to be more robust
against leap seconds and settimeofday() calls.

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging/fbtft : Fix multiple/missing blank line issues

Remove or add blank lines as recommended by checkpatch.pl

Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging/fbtft : Remove FSF mailing address

checkpatch.pl recommends that this is no longer required.
Also replaces ASCII-art copyright notice with simple text

Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Remove unnecessary externs

Using 'extern' is not necessary for function prototypes.

Miscellanea:

o Reflow alignments

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: core: Don't set device platform_data

Pass platform_data as an argument to fbtft_framebuffer_alloc()
instead of using dev->platform_data.

This fixes an issue where the device comes from Device Tree
and fbtft_probe_common() sets dev->platform_data to allocated
memory. When the module is reloaded, dev->platform_data points
to freed memory.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: replace fbtft_dev_dbg with standard dev_dbg call

This patch attempts to simplify the debugging using standard
dev_dbg call so that individual debug prints can be enabled or
disbled by dynamic debugging rather than using module params.

Signed-off-by: Madhusudhanan Ravindran <mravindr@visteon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Fix typo in fbtft

This patch fix spelling typo in comment and printk within fbtft

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Remove do {} while(0) in single statement macro

This patch fixes the checkpatch.pl warning:

WARNING: Single statement macros should not use a do {} while (0) loop
+#define write_reg(par, ...) \
+do { \
+ par->fbtftops.write_register(par, NUMARGS(__VA_ARGS__), __VA_ARGS__); \
+} while (0)

Signed-off-by: Helen Fornazier <helen.fornazier@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: Fix indentation style by space

This patch fixes the checkpatch.pl warning and error:

WARNING: please, no spaces at the start of a line

ERROR: code indent should use tabs where possible

Signed-off-by: Helen Fornazier <helen.fornazier@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: fbtft: core support

This commit adds the core fbtft framework from
https://github.com/notro/fbtft.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Noralf Tronnes <notro@tronnes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>