The Atmel maxtouch DT binding documents that the compatible string for
the device is "atmel,maxtouch" and the I2C core always reports a module
alias of the form i2c:alias where alias is the compatible string model:

$ grep MODALIAS /sys/devices/platform/12e00000.i2c/i2c-8/8-004b/uevent
MODALIAS=i2c:maxtouch

But there isn't maxtouch entry in the I2C device ID table so when the
i2c:maxtouch MODALIAS uevent is reported, kmod is not able to match the
alias with a module to load:

$ modinfo atmel_mxt_ts | grep alias
alias:          of:N*T*Catmel,maxtouch
alias:          i2c:mXT224
alias:          i2c:atmel_mxt_tp
alias:          i2c:atmel_mxt_ts
alias:          i2c:qt602240_ts

So add the maxtouch entry to the I2C device ID table to allow the module
to be autoloaded when the device is registered via OF.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Apparently people are installing generic Linux distributions not only on
Pixels but also on other Chromebooks. Unfortunately on all of them Atmel
parts assigned names ATML0000 and ATML0001, and do not carry any other
configuration data. So let's create generic instance of platform data that
should cover most of them (we assume that they will not be using T100
objects, since with those Google mapped BTN_LEFT onto a different GPIO, so
slightly different keymap would be needed, but I think we used parts with
T100 on ARM devices where we thankfully have DTS and can describe the
devices better).
Tested-by: NRich K <rgkirch@gmail.com>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

This indicates the device coordinates should be directly mapped to screen.
This is valid since scaling/flipping/rotation should be done by configuring
the MXT device.

It also flags to Android using INPUT_PROP_DIRECT that the device should be
treated as a touch screen by default, and removes the necessity for a
default IDC file.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

The CHG/interrupt line is momentarily set (approximately 100 ms) as an
input after power-up or reset for diagnostic purposes. This may cause
spurious interrupts, so disable interrupt handler during this period.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Use function rather than loop, define np to reduce wrapping.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

input_dev may be NULL if mxt_initialize_input_device fails. But pm ops is
still available and suspend/resume assume
input_dev is not NULL. To fix this issue, we add a check if (!input_dev).
Signed-off-by: NPan Xinhui <xinhuix.pan@intel.com>
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Many of these values are out of date and they aren't used in the driver
- all they do is increase the size of the kernel source.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

The hardcoded 0x83 CTRL setting overrides other settings in that byte,
enabling extra reporting that may not be useful on a particular platform.

Implement improved suspend mechanism via deep sleep. By writing zero to
both the active and idle cycle times the maXTouch device can be put into a
deep sleep mode, using minimal power. It is necessary to issue a calibrate
command after the chip has spent any time in deep sleep, however a soft
reset is unnecessary.

Use the old method on Chromebook Pixel via platform data option.

This patch also deals with the situation where the power configuration is
zero on probe, which would mean that the device never wakes up to execute
commands.

After a config download, the T7 power configuration may have changed so it
is necessary to re-read it.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

i2c_driver does not need to set an owner because i2c_register_driver()
will set it.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

This makes the intent a tad more clear.
Reviewed-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

This change allows atmel_mxt_ts to bind to ACPI-enumerated devices in
Google Pixel 2 (2015).

While newer version of ACPI standard allow use of device-tree-like
properties in device descriptions, the version of ACPI implemented in
Google BIOS does not support them, and we have to resort to DMI data to
specify exact characteristics of the devices (touchpad vs. touchscreen,
GPIO to button mapping, etc).

Pixel 1 continues to use i2c devices and platform data created by
chromeos-laptop driver, since ACPI does not enumerate them.
Reviewed-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

If the "linux,gpio-keymap" DT property is defined, the T19 keys are
configured and the device is setup as a touchpad rather than a touchscreen.
The logic is part of the input device initialization routine but it can be
factored out to its own function to simplify the former.
Signed-off-by: NSjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Add support for the new T100 object which replaces the previous T9
multitouch touchscreen object in recent maXTouch devices. T100 provides
improved reporting with selectable auxiliary information, and a type field
for hover/stylus/glove reporting.

The hovering finger support was based on Chung-Yih's work in the ChromiumOS
downstream kernel:

https://chromium-review.googlesource.com/#/c/219280/Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NYufeng Shen <miletus@chromium.org>
[javier: Factor out T9 and T100 init functions and rework hover support]
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

This reverts commit 9d469d03.

It breaks the Chromebook Pixel touchpad (and touchscreen).
Reported-by: NDirk Hohndel <dirk@hohndel.org>
Bisected-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Dyer <nick.dyer@itdev.co.uk>
Cc: Benson Leung <bleung@chromium.org>
Cc: Yufeng Shen <miletus@chromium.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: stable@vger.kernel.org  # v3.16+
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use __maybe_unused instead of ifdef guards around suspend/resume
functions, in order to increase build coverage and fix build warnings.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

[Nick Dyer: reworked to move free of input device into separate function
and only call in paths that require it.]
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

In the case where the CHG/interrupt line mode is not configured correctly,
this warning is output to dmesg output for each interrupt. Downgrade the
message to debug.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

This should fix the following issues reported by Coverity:

*** CID 1230625:  Logically dead code  (DEADCODE)
/drivers/input/touchscreen/atmel_mxt_ts.c: 1692 in mxt_initialize()

*** CID 12306276:  Missing break in switch  (MISSING_BREAK)
/drivers/input/touchscreen/atmel_mxt_ts.c: 1436 in mxt_get_object_table()

*** CID 1230629:  Out-of-bounds write  (OVERRUN)
/drivers/input/touchscreen/atmel_mxt_ts.c: 1267 in mxt_update_cfg()

*** CID 1230632:  Unused pointer value  (UNUSED_VALUE)
/drivers/input/touchscreen/atmel_mxt_ts.c: 1211 in mxt_update_cfg()
Acked-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Let's split config update code a bit so it is hopefully a bit easier to
read. Also, the firmware update callback should be the entity releasing
firmware blob, not lower layers.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>

I think having control flow with 2 goto/labels/flags is quite hard to read,
this version is a bit more readable IMO.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>

Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

By writing zero to both the active and idle cycle times the maXTouch device
is put into a deep sleep mode when it consumes minimal power. It is
unnecessary to change the configuration of any other objects (for example
to disable T9 touchscreen).

It is counterproductive to reset the chip on resume, it will result in a
long delay. However it is necessary to issue a calibrate command after the
chip has spent any time in deep sleep.

This patch also deals with the situation where the power configuration is
zero on probe, which would mean that the device never wakes up to execute
commands.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

maXTouch chips allow the reading of multiple messages in a single I2C
transaction, which reduces bus overhead and improves performance/latency. The
number of messages available to be read is given by the value in the T44
object which is located directly before the T5 object.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

This is in preparation for support of the T44 message count object.

Also, cache T5 address to avoid lookup on every interrupt cycle.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

By storing the previous T6 status byte multiple debug output of the same
status can be suppressed (for example CFGERR).
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

The T5 object may have various sizes depending on the objects used on the
particular maXTouch chip and firmware version, therefore it can't be
hardcoded in the driver. Allocate a buffer on probe instead.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

The MXT device may be in bootloader mode on probe, due to:
1) APP CRC failure, either:
  a) flash corruption
  b) bad power or other intermittent problem while checking CRC
2) If the device has been reset 10 or more times without accessing comms
3) Warm probe, device was in bootloader mode already

This code attempts to recover from 1(b) and 3.

There is an additional complexity: we have to try two possible bootloader
addresses because the mapping is not one-to-one and we don't know the exact
model yet.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Later chips (for example mXT1664S) different mappings for bootloader
addresses.  This means that we must look at the family ID to determine
which address to use.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

On a warm probe, the device might be in a state where an flash operation was
not completed.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

If the bootloader on the touchscreen controller fails to initialise the
firmware image, it stays in bootloader mode and reports a failure. It is
possible to reflash a working firmware image from this state.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

By validating the checksum, we can identify if the configuration is
corrupt.  In addition, this patch writes the configuration in a short
series of block writes rather than as many individual values.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

The existing implementation which encodes the configuration as a binary
blob in platform data is unsatisfactory since it requires a kernel
recompile for the configuration to be changed, and it doesn't deal well
with firmware changes that move values around on the chip.

Atmel define an ASCII format for the configuration which can be exported
from their tools. This patch implements a parser for that format which
loads the configuration via the firmware loader and sends it to the MXT
chip.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Touchpads are pointers, so make sure to pass the correct values to
input_mt_report_pointer_emulation(). Without this, tap-to-click doesn't
work.
Signed-off-by: NBenson Leung <bleung@chromium.org>
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

It is useful to initialise the input device later:
- Screen parameters may not be not known yet, for instance if waiting for
  firmware loader to return.
- Device may be in bootloader mode on probe (but could still be recovered by
  firmware download).

In addition, later devices have a different touchscreen object (T100) which
requires handling differently.

This also reduces the complexity of the probe function.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

The maXTouch chips use the CHG line to generate status events in bootloader
mode, and during configuration download, before there is enough information
to configure the input device. Therefore set up the interrupt handler
earlier.

However, this introduces states where parts of the interrupt processing
must not run. Use data->object_table as a way to tell whether the chip
information is valid, and data->input_dev as a way to tell whether it is
valid to generate input report.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

The patch e57a66aa: "Input: atmel_mxt_ts - read and report
bootloader version" from May 18, 2014, leads to the following static
checker warning:

	drivers/input/touchscreen/atmel_mxt_ts.c:437 mxt_get_bootloader_version()
	warn: signedness bug returning '(-5)'

drivers/input/touchscreen/atmel_mxt_ts.c
   429  static u8 mxt_get_bootloader_version(struct mxt_data *data, u8 val)
   430  {
   431          struct device *dev = &data->client->dev;
   432          u8 buf[3];
   433
   434          if (val & MXT_BOOT_EXTENDED_ID) {
   435                  if (mxt_bootloader_read(data, &buf[0], 3) != 0) {
   436                          dev_err(dev, "%s: i2c failure\n", __func__);
   437                          return -EIO;
                                       ^^^^
This gets truncated into a number from 0-255 and anyway the caller
doesn't check for errors.

(reported by Dan Carpenter)
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

This avoids confusion with the newer T100 touchscreen object.
Signed-off-by: NNick Dyer <nick.dyer@itdev.co.uk>
Acked-by: NBenson Leung <bleung@chromium.org>
Acked-by: NYufeng Shen <miletus@chromium.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>