The ili251x firmware can be updated, this is used when switching between
different modes of operation of the touch surface, e.g. glove operation.
This patch implements the firmware update mechanism triggered by a write
into an sysfs attribute.

The firmware itself is distributed as an intel hex file with non-standard
types. The first two lines are of type 0xad, which indicates the start of
DataFlash payload, that is always at address 0xf000 on the ili251x, so it
can be dropped, and 0xac which indicates the position of firmware info in
the Application payload, that is always at address 0x2020 on the ili251x
and we do not care. The rest of the firmware is data of type 0x00, and we
care about that. To convert the firmware hex file into something usable
by the kernel, remove the first two lines and then use ihex2fw:

 $ tail -n +3 input.hex > temp.hex
 $ ./tools/firmware/ihex2fw temp.hex firmware/ilitek/ili251x.bin

To trigger the firmware update, place firmware file ilitek/ili251x.bin
into /lib/firmware/, write into firmware_update sysfs attribute and wait
about 30-40 seconds. The firmware update is slow. Afterward, verify the
firmware_version and mode sysfs attributes to check whether the firmware
got updated and the controller switched back to application (AP) mode by
reading out 'mode' attribute in sysfs.

Note that the content of firmware_version, e.g. 0600.0005.abcd.aa04 can
be matched to the content of the firmware hex file. The first four bytes,
0x06 0x00 0x00 0x05 can be found at ^:102030 00 05000006, the next four
bytes 0xab 0xcd 0xaa 0x04 at ^:10F000 00 nnnnnnnn ABCDAA04.

Note that the protocol differs considerably between the ili2xxx devices,
this patch therefore implements this functionality only for ili251x that
I can test.

Signed-off-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20210831202506.181927-3-marex@denx.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

There is a spelling mistake in the Kconfig text. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210704095702.37567-1-colin.king@canonical.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

This patch adds support for Hycon HY46XX.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Link: https://lore.kernel.org/r/20210413144446.2277817-4-giulio.benetti@benettiengineering.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Add support for ILITEK Lego series of touch devices.
Lego series includes ILITEK 213X/23XX/25XX.

Tested/passed with evaluation board with ILI2520/2322 IC.

Signed-off-by: Joe Hung <joe_hung@ilitek.com>
Link: https://lore.kernel.org/r/20210324122601.125873-2-joe_hung@ilitek.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Add support for the msg2638 touchscreen IC from MStar.
Firmware handling, wakeup gestures and other specialties are not supported.
This driver reuses zinitix.c structure, while the checksum and irq handler
functions are based on out-of-tree driver for Alcatel Idol 3 (4.7").

Signed-off-by: Vincent Knecht <vincent.knecht@mailoo.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210305153815.126937-2-vincent.knecht@mailoo.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Some devices outside of drivers/input/touchscreen/ can still make
use of the touchscreen helper functions. Therefore, it was agreed
in [1] to move them outside of drivers/input/touchscreen/ so that
other devices can call them without INPUT_TOUCHSCREEN being set.

As part of this change, 'of' is dropped from the filename because
the helpers no longer actually use OF. No changes are made to the
file contents whatsoever.

Based on the feedback in [2], the corresponding binding documents
(touchscreen.yaml and touchscreen.txt) are left in their original
locations.

[1] https://patchwork.kernel.org/patch/11924029/
[2] https://patchwork.kernel.org/patch/12042037/

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20210301234928.4298-2-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge with mainline to get latest APIs and device tree bindings.

devm_ioremap_resource() is only guaranteed to be present if
CONFIG_HAS_IOMEM is set.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/YCyauGyqxut69JNz@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

When TOUCHSCREEN_ADC is enabled and IIO_BUFFER is disabled, it results
in the following Kbuild warning:

WARNING: unmet direct dependencies detected for IIO_BUFFER_CB
  Depends on [n]: IIO [=y] && IIO_BUFFER [=n]
  Selected by [y]:
  - TOUCHSCREEN_ADC [=y] && !UML && INPUT [=y] && INPUT_TOUCHSCREEN [=y] && IIO [=y]

The reason is that TOUCHSCREEN_ADC selects IIO_BUFFER_CB without depending
on or selecting IIO_BUFFER while IIO_BUFFER_CB depends on IIO_BUFFER. This
can also fail building the kernel.

Honor the kconfig dependency to remove unmet direct dependency warnings
and avoid any potential build failures.

Fixes: aa132ffb6b0a ("input: touchscreen: resistive-adc-touch: add generic resistive ADC touchscreen")
Signed-off-by: Necip Fazil Yildiran <fazilyildiran@gmail.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20201102221504.541279-1-fazilyildiran@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Add support for the bt541 touchscreen IC from zinitix, loosely based on
downstream driver. The driver currently supports multitouch (5 touch points).
The bt541 seems to support touch keys, but the support was not added because
that functionality is not being utilized by the touchscreen used for testing.
Based on the similartities between downstream drivers, it seems likely that
other similar touchscreen ICs can be supported with this driver in the future.

Signed-off-by: Michael Srba <Michael.Srba@seznam.cz>
Link: https://lore.kernel.org/r/20201001122949.16846-1-michael.srba@seznam.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>