Commit Graph
39 Commits
Author SHA1 Message Date
tmakin 08bd2cf2fd stmfts: update touch handling 2026-10-10 11:18:03 -05:00
tmakin 5c7245e156 stmfts: support FTM4 chips
Some FingerTipS chips use FTM4 variants like Ftm4cd60d

Based loosely on
https://github.com/android-linux-stable/bluecross/blob/android-msm-bluecross-4.9/drivers/input/touchscreen/stm/ftm4_ts.c
and
https://github.com/CTCaer/switch-l4t-kernel-4.9/blob/linux-dev/drivers/input/touchscreen/stm/ftm4_ts.c

Assisted-by: Grok:grok-4.6
2026-10-07 10:26:55 -05:00
David Heidelberg 9261922c66 Input: stmfts - support FTS5
The FTS support SLPI and AP mode, introduce mode-switch GPIO to switch
between those two. Currently we can handle only full power AP mode, so we
just keep the AP on.

Useful for devices like Pixel 3 (blueline), Pixel 4a (sunfish),
Xiaomi Mi 8 (dipper), and many others.

Based on work of Petr Hodina <petr.hodina@protonmail.com>

Signed-off-by: David Heidelberg <david@ixit.cz>
2026-10-06 19:01:54 -05:00
David Heidelberg 36fa0b8913 Input: stmfts - wait for controller ready after reset
After releasing the reset line stmfts_reset() sleeps a fixed 50 ms and
stmfts_power_on() another 50 ms before the first I2C access.  That is
enough for a warm reset, but when both supplies were really cut during
system suspend the controller boots from cold and can need longer.  If
it does, the first read fails, stmfts_resume() returns an error and the
touchscreen is left powered off with its interrupt disabled.

The controller posts a controller ready event once it has booted, and
the event parser already completes cmd_done on it.  Enable the interrupt
right after releasing reset and wait for that event instead of sleeping,
giving the controller 300 ms, the total budget the vendor driver allows.
Boards without a reset line keep the old timing.

Usually phones such as Pixel 4a and Xiaomi Mi 8 needs longer delay, so
without this change touchscreen stops working.

Fixes: 8a1f9de80e45 ("Input: stmfts - add optional reset GPIO support")
Cc: stable@vger.kernel.org
Co-developed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
2026-10-06 19:01:43 -05:00
Uwe Kleine-König (The Capable Hub) dcea3dc03a Input: Use named initializers for arrays of i2c_device_data
While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.

The mentioned robustness is relevant for a planned change to struct
i2c_device_id that replaces .driver_data by an anonymous union.

This patch doesn't modify the compiled arrays, only their representation
in source form benefits. The former was confirmed with x86 and arm64
builds.

Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20260515164848.497608-2-u.kleine-koenig@baylibre.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-10-06 19:01:38 -05:00
Dmitry Torokhov dd36ee6907 Input: stmfts - fix formatting issues
Fix a few formatting issues reported by checkpatch.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-10-06 19:01:38 -05:00
Petr Hodina cdd38f1012 Input: stmfts - add optional reset GPIO support
Add support for an optional "reset-gpios" property. If present, the
driver drives the reset line high at probe time and releases it during
power-on, after the regulators have been enabled.

Signed-off-by: Petr Hodina <petr.hodina@protonmail.com>
Co-developed-by: David Heidelberg <david@ixit.cz>
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-8-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-10-06 19:01:38 -05:00
Petr Hodina f70d95850e Input: stmfts - use client to make future code cleaner
Make code cleaner, compiler will optimize it away anyway.

Preparation for FTM5 support, where more steps are needed.

Signed-off-by: Petr Hodina <petr.hodina@protonmail.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-6-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-10-06 19:01:38 -05:00
David Heidelberg 4f8d7f167d Input: stmfts - disable regulators and disable irq when power on fails
We must power off regulators and ensure that IRQ is disabled when
failing at power on phase. Create stmfts_configure function to limit
use of goto.

Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-5-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-10-06 18:55:01 -05:00
David Heidelberg 965c9d231b Input: stmfts - abstract reading information from the firmware
Improves readability and makes splitting power on function in following
commit easier.

Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-4-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-10-06 18:55:01 -05:00
David Heidelberg 2fcfbdae10 Input: stmfts - switch to devm_regulator_bulk_get_const
Switch to devm_regulator_bulk_get_const() to stop setting the supplies
list in probe(), and move the regulator_bulk_data struct in static const.

Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-3-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-10-06 18:55:01 -05:00
David Heidelberg d3fd5a30ad Input: stmfts - use dev struct directly
Makes the code better readable and noticably shorter.

Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-2-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-10-06 18:55:01 -05:00
David Heidelberg 91275a8004 Input: stmfts - fix the MODULE_LICENSE() string
Replace the bogus "GPL v2" with "GPL" as MODULE_LICNSE() string. The
value does not declare the module's exact license, but only lets the
module loader test whether the module is Free Software or not.

See commit bf7fbeeae6 ("module: Cure the MODULE_LICENSE "GPL" vs.
"GPL v2" bogosity") in the details of the issue. The fix is to use
"GPL" for all modules under any variant of the GPL.

Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-1-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-10-06 18:55:01 -05:00
Dmitry Torokhov 8665ceb926 Input: stmfts - use guard notation when acquiring mutex
Guard notation simplifies code.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2026-03-25 07:53:58 -07:00
Petr Hodina 995186145d Input: stmfts - use sysfs_emit() instead of sprintf()
Follow the advice in Documentation/filesystems/sysfs.rst:
show() should only use sysfs_emit() or sysfs_emit_at() when formatting
the value to be returned to user space.

Signed-off-by: Petr Hodina <petr.hodina@protonmail.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20251215-fts-fixes-v1-3-8c1e3a63ebf1@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2025-12-15 21:57:02 -08:00
Petr Hodina f5c3c77b86 Input: stmfts - make comments correct
No functional change.

Fixes: 78bcac7b2a ("Input: add support for the STMicroelectronics FingerTip touchscreen")
Signed-off-by: Petr Hodina <petr.hodina@protonmail.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20251215-fts-fixes-v1-2-8c1e3a63ebf1@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2025-12-15 21:51:16 -08:00
David Heidelberg 385a53867b Input: stmfts - correct wording for the warning message
We're trying to enable regulator, not disable it.

Fixes: 78bcac7b2a ("Input: add support for the STMicroelectronics FingerTip touchscreen")
Suggested-by: Petr Hodina <petr.hodina@protonmail.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20251215-fts-fixes-v1-1-8c1e3a63ebf1@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2025-12-15 21:51:01 -08:00
Uwe Kleine-König 5852f2afcd Input: drop explicit initialization of struct i2c_device_id::driver_data to 0
These drivers don't use the driver_data member of struct i2c_device_id,
so don't explicitly initialize this member.

This prepares putting driver_data in an anonymous union which requires
either no initialization or named designators. But it's also a nice
cleanup on its own.

While add it, also remove commas after the sentinel entries.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20240509174158.2211071-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2024-05-13 15:43:19 -07:00
Dmitry Torokhov 6cc3ecfded Input: stmfts - use device core to create driver-specific device attributes
Instead of creating driver-specific device attributes with
devm_device_add_group() have device core do this by setting up dev_groups
pointer in the driver structure.

Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230729005133.1095051-20-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2023-09-06 14:29:03 -07:00
Uwe Kleine-König d8bde56dfd Input: Switch i2c drivers back to use .probe()
After commit b8a1a4cd5a ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230517164645.162294-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2023-05-17 09:59:11 -07:00
Jonathan Cameron 90208b31f9 Input: stmfts - switch to SYSTEM_SLEEP_/RUNTIME_PM_OPS() and pm_ptr()
SET_SYSTEM_SLEEP_PM_OPS() and SET_RUNTIME_PM_OPS() are deprecated as
they require explicit protection against unused function warnings.
The new combination of pm_ptr() and SYSTEM_SLEEP_PM_OPS()/
RUNTIME_PM_OPS() allows the compiler to see the functions,
thus suppressing the warning, but still allowing the unused code to be
removed. Thus also drop the __maybe_unused markings.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Andi Shyti <andi@etezian.org>
Link: https://lore.kernel.org/r/20230114171620.42891-7-jic23@kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2023-01-27 14:49:52 -08:00
Uwe Kleine-König 3d2f81819a Input: stmfts - Convert to i2c's .probe_new()
The probe function doesn't make use of the i2c_device_id * parameter so it
can be trivially converted.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20221118224540.619276-261-uwe@kleine-koenig.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-12-02 14:53:47 -08:00
Uwe Kleine-König ed5c2f5fd1 i2c: Make remove callback return void
The value returned by an i2c 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.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-08-16 12:46:26 +02:00
Dmitry Torokhov 5f76955ab1 Input: stmfts - do not leave device disabled in stmfts_input_open
The commit 26623eea0d attempted to deal with potential leak of runtime
PM counter when opening the touchscreen device, however it ended up
erroneously dropping the counter in the case of successfully enabling the
device.

Let's address this by using pm_runtime_resume_and_get() and then executing
pm_runtime_put_sync() only when we fail to send "sense on" command to the
device.

Fixes: 26623eea0d ("Input: stmfts - fix reference leak in stmfts_input_open")
Reported-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-05-26 09:57:07 -07:00
Zheng Yongjun 26623eea0d Input: stmfts - fix reference leak in stmfts_input_open
pm_runtime_get_sync() will increment pm usage counter even it
failed. Forgetting to call pm_runtime_put_noidle will result
in reference leak in stmfts_input_open, so we should fix it.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Link: https://lore.kernel.org/r/20220317131604.53538-1-zhengyongjun3@huawei.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2022-03-20 21:59:43 -07:00
Barry Song bcd9730a04 Input: move to use request_irq by IRQF_NO_AUTOEN flag
disable_irq() after request_irq() still has a time gap in which
interrupts can come. request_irq() with IRQF_NO_AUTOEN flag will
disable IRQ auto-enable because of requesting.

On the other hand, request_irq() after setting IRQ_NOAUTOEN as
below
irq_set_status_flags(irq, IRQ_NOAUTOEN);
request_irq(dev, irq...);
can also be replaced by request_irq() with IRQF_NO_AUTOEN flag.

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Link: https://lore.kernel.org/r/20210302224916.13980-3-song.bao.hua@hisilicon.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2021-03-25 15:27:56 -07:00
YueHaibing d04afe14b2 Input: stmfts - fix a & vs && typo
In stmfts_sysfs_hover_enable_write(), we should check value and
sdata->hover_enabled is all true.

Fixes: 78bcac7b2a ("Input: add support for the STMicroelectronics FingerTip touchscreen")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20200916141941.16684-1-yuehaibing@huawei.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2020-09-16 10:38:58 -07:00
Gustavo A. R. Silva 6f49c4f5b9 Input: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200707180857.GA30600@embeddedor
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2020-07-07 11:25:54 -07:00
Jiada Wang 5fc70e350e Input: introduce input_mt_report_slot_inactive()
input_mt_report_slot_state() ignores "tool" argument when the slot is
closed, which has caused a bit of confusion. Let's introduce
input_mt_report_slot_inactive() to report inactive slot state.

Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Link: https://lore.kernel.org/r/20200508055656.96389-2-jiada_wang@mentor.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2020-05-12 13:18:26 -07:00
Dmitry Torokhov 937c4e552f Input: stmfts - acknowledge that setting brightness is a blocking call
We need to turn regulators on and off when switching brightness, and
that may block, therefore we have to set stmfts_brightness_set() as
LED's brightness_set_blocking() method.

Fixes: 78bcac7b2a ("Input: add support for the STMicroelectronics FingerTip touchscreen")
Acked-by: Andi Shyti <andi@etezian.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2019-02-07 23:41:11 -08:00
Andi Shyti adf313f41a Input: stmfts, s6sy761 - update my e-mail
Because I will be leaving Samsung soon, for reachability update
my reference e-mail to etezian.org.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-03-30 15:31:41 -07:00
Marek Szyprowski 1d96000360 Input: stmfts - use async probe & suspend/resume to avoid 2s delay
Executing stmfts_power_on() function lasts over 2 seconds, what
significantly slows down the boot and resume processes if driver is
compiled in. Avoid this delay by forcing this driver to be probed
and suspended/resumed asynchronously.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-03-30 15:31:41 -07:00
Andi Shyti cba04cdf43 Input: stmfts - set IRQ_NOAUTOEN to the irq flag
The interrupt is requested before the device is powered on and
it's value in some cases cannot be reliable. It happens on some
devices that an interrupt is generated as soon as requested
before having the chance to disable the irq.

Set the irq flag as IRQ_NOAUTOEN before requesting it.

This patch mutes the error:

  stmfts 2-0049: failed to read events: -11

received sometimes during boot time.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-01-22 17:35:16 -08:00
Andi Shyti f8c5938f69 Input: stmfts,s6sy671 - add SPDX identifier
Replace the original license statement with the SPDX identifier.

Update also the copyright owner adding myself as co-owner of the
copyright.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-01-22 16:25:48 -08:00
Dmitry Torokhov 91de76e661 Merge tag 'v4.14-rc6' into next
Merge with mainline to bring in the timer API changes.
2017-10-23 11:43:40 -07:00
Chanwoo Choi c9bfb2f003 Input: stmfts - fix setting ABS_MT_POSITION_* maximum size
The commit 78bcac7b2a ("Input: add support for the STMicroelectronics
FingerTip touchscreen) used the 'touchscreen_parse_properties()' helper
function in order to get the value of common properties.

But, commit 78bcac7b2a didn't set the capability of ABS_MT_POSITION_*
before calling touchscreen_parse_properties(). In result, the max_x and
max_y of 'struct touchscreen_properties' were not set.

Fixes: 78bcac7b2a ("Input: add support for the STMicroelectronics FingerTip touchscreen")
Cc: stable@vger.kernel.org
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-10-18 17:54:13 -07:00
Andi Shyti c2690bd697 Input: stmfts - use devm_device_add_group
instead of sysfs_create_group.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-09-22 10:06:58 -07:00
Arnd Bergmann d4c9354b40 Input: stmfts - mark all PM functions as __maybe_unused
We get a harmless warning when CONFIG_RUNTIME_PM is disabled:

drivers/input/touchscreen/stmfts.c:760:12: error: 'stmfts_runtime_resume' defined but not used [-Werror=unused-function]
 static int stmfts_runtime_resume(struct device *dev)
drivers/input/touchscreen/stmfts.c:748:12: error: 'stmfts_runtime_suspend' defined but not used [-Werror=unused-function]
 static int stmfts_runtime_suspend(struct device *dev)

The regular PM functions are already marked as __maybe_unused, so let's
do the same for the runtime-PM as well.

Fixes: 78bcac7b2a ("Input: add support for the STMicroelectronics FingerTip touchscreen")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-06-09 09:54:56 -07:00
Andi Shyti 78bcac7b2a Input: add support for the STMicroelectronics FingerTip touchscreen
The stmfts (ST-Microelectronics FingerTip S) touchscreen device is a
capacitive multi-touch controller mainly for mobile use.  It's connected
through i2c bus at the address 0x49 and it interfaces with userspace
through input event interface.

At the current state it provides a touchscreen multitouch functionality up
to 10 fingers. Each finger is enumerated with a distinctive id (from 0 to
9).

If enabled the device can support single "touch" hovering, by providing
three coordinates, x, y and distance.

It is possible to select the touchkey functionality which provides a basic
two keys interface for "home" and "back" menu, typical in mobile phones.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-06-05 15:35:34 -07:00