Hard-coding resolution for st1633 device was wrong. Some of LCDs like
YTS700TLBC-02-100C has assembled Sitronix st1633 touchcontroller too. But
the resolution is not 320x480 as was hard-coded.
Add new function which reads correct resolution directly from register.
Signed-off-by: Andrej Valek <andrej.valek@siemens.com>
Link: https://lore.kernel.org/r/20201103073949.12198-1-andrej.valek@siemens.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the kerneldoc warnings from building the driver with W=1.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-2-lee.jones@linaro.org
[dtor: folded together several Lee's patches; added more descriptions]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

In file included from drivers/input/touchscreen/cyttsp_i2c_common.c:24:
 drivers/input/touchscreen/cyttsp4_core.h:236:27: warning: ‘cyttsp4_tch_abs_string’ defined but not used [-Wunused-const-variable=]
 236 | static const char  const cyttsp4_tch_abs_string[] = {
 | ^~~~~~~~~~~~~~~~~~~~~~
 In file included from drivers/input/touchscreen/cyttsp4_i2c.c:17:
 drivers/input/touchscreen/cyttsp4_core.h:236:27: warning: ‘cyttsp4_tch_abs_string’ defined but not used [-Wunused-const-variable=]
 236 | static const char * const cyttsp4_tch_abs_string[] = {
 | ^~~~~~~~~~~~~~~~~~~~~~
 In file included from drivers/input/touchscreen/cyttsp4_spi.c:17:
 drivers/input/touchscreen/cyttsp4_core.h:236:27: warning: ‘cyttsp4_tch_abs_string’ defined but not used [-Wunused-const-variable=]
 236 | static const char * const cyttsp4_tch_abs_string[] = {
 | ^~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-16-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/touchscreen/resistive-adc-touch.c:34: warning: cannot understand function prototype: 'struct grts_state '
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-10-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The location of the minus sign and the error code are
linked together for better human view.
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20201027135020.66632-1-zhangqilong3@huawei.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/mouse/cyapa_gen5.c:392: warning: Function parameter or member 'cyapa' not described in 'cyapa_i2c_pip_write'
 drivers/input/mouse/cyapa_gen5.c:392: warning: Function parameter or member 'buf' not described in 'cyapa_i2c_pip_write'
 drivers/input/mouse/cyapa_gen5.c:392: warning: Function parameter or member 'size' not described in 'cyapa_i2c_pip_write'
 drivers/input/mouse/cyapa_gen5.c:444: warning: Function parameter or member 'cyapa' not described in 'cyapa_empty_pip_output_data'
 drivers/input/mouse/cyapa_gen5.c:444: warning: Function parameter or member 'buf' not described in 'cyapa_empty_pip_output_data'
 drivers/input/mouse/cyapa_gen5.c:444: warning: Function parameter or member 'len' not described in 'cyapa_empty_pip_output_data'
 drivers/input/mouse/cyapa_gen5.c:444: warning: Function parameter or member 'func' not described in 'cyapa_empty_pip_output_data'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-4-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/mouse/cyapa.c:130: warning: Function parameter or member 'reg' not described in 'cyapa_i2c_write'
 drivers/input/mouse/cyapa.c:130: warning: Excess function parameter 'ret' description in 'cyapa_i2c_write'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-3-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/misc/ab8500-ponkey.c:32: warning: Function parameter or member 'idev' not described in 'ab8500_ponkey'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-5-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/keyboard/cros_ec_keyb.c:72: warning: cannot understand function prototype: 'struct cros_ec_bs_map '
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-8-lee.jones@linaro.org
[dtor: fixed up docbook comments for cros_ec_keyb structure as well]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/keyboard/gpio_keys.c:119: warning: Function parameter or member 'dev' not described in 'get_bm_events_by_type'
 drivers/input/keyboard/gpio_keys.c:119: warning: Excess function parameter 'input' description in 'get_bm_events_by_type'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-12-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/mouse/elantech.c:1837: warning: Function parameter or member 'psmouse' not described in 'elantech_setup_smbus'
 drivers/input/mouse/elantech.c:1837: warning: Function parameter or member 'info' not described in 'elantech_setup_smbus'
 drivers/input/mouse/elantech.c:1837: warning: Function parameter or member 'leave_breadcrumbs' not described in 'elantech_setup_smbus'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-13-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'num_rows' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'num_cols' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'input' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'regmap' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'key_sense_irq' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'key_stuck_irq' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'keycodes' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'dev' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'keystate' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'stuckstate' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'ctrl_reg' not described in 'pmic8xxx_kp'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-21-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/keyboard/nomadik-ske-keypad.c:71: warning: Function parameter or member 'pclk' not described in 'ske_keypad'
 drivers/input/keyboard/nomadik-ske-keypad.c:71: warning: Function parameter or member 'ske_keypad_lock' not described in 'ske_keypad'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-20-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/misc/drv2667.c:109: warning: Function parameter or member 'input_dev' not described in 'drv2667_data'
 drivers/input/misc/drv2667.c:109: warning: Function parameter or member 'client' not described in 'drv2667_data'
 drivers/input/misc/drv2667.c:109: warning: Function parameter or member 'regmap' not described in 'drv2667_data'
 drivers/input/misc/drv2667.c:109: warning: Function parameter or member 'work' not described in 'drv2667_data'
 drivers/input/misc/drv2667.c:109: warning: Function parameter or member 'regulator' not described in 'drv2667_data'
 drivers/input/misc/drv2667.c:109: warning: Function parameter or member 'page' not described in 'drv2667_data'
 drivers/input/misc/drv2667.c:109: warning: Function parameter or member 'magnitude' not described in 'drv2667_data'
 drivers/input/misc/drv2667.c:109: warning: Function parameter or member 'frequency' not described in 'drv2667_data'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-19-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/misc/drv2665.c:59: warning: Function parameter or member 'input_dev' not described in 'drv2665_data'
 drivers/input/misc/drv2665.c:59: warning: Function parameter or member 'client' not described in 'drv2665_data'
 drivers/input/misc/drv2665.c:59: warning: Function parameter or member 'regmap' not described in 'drv2665_data'
 drivers/input/misc/drv2665.c:59: warning: Function parameter or member 'work' not described in 'drv2665_data'
 drivers/input/misc/drv2665.c:59: warning: Function parameter or member 'regulator' not described in 'drv2665_data'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-18-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixes the following W=1 kernel build warning(s):

 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'input_dev' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'client' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'regmap' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'work' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'enable_gpio' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'regulator' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'magnitude' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'mode' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'library' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'rated_voltage' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:194: warning: Function parameter or member 'overdrive_voltage' not described in 'drv260x_data'
 drivers/input/misc/drv260x.c:244: warning: Function parameter or member 'voltage' not described in 'drv260x_calculate_voltage'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-17-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Use kobj_to_dev() instead of container_of().
Signed-off-by: Wang Qing <wangqing@vivo.com>
Link: https://lore.kernel.org/r/1604893436-20206-1-git-send-email-wangqing@vivo.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The eKTF2132 is a touchscreen controller found, for example, in the Kobo
Aura ebook reader. It is similar to the ektf2127, but it uses a different
packet type to report touch events.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20201106112412.390724-3-j.neuschaefer@gmx.netSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The eKTF2132 is a touchscreen controller found, for example, in the Kobo
Aura ebook reader. It is similar to the ektf2127, but it uses a different
packet type to report touch events.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20201106112412.390724-2-j.neuschaefer@gmx.netSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

I am the author of this SiS touch driver, and willing to maintain and
develop it further.
Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com>
Link: https://lore.kernel.org/r/20201007035108.58636-1-mika.penttila@nextfour.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

All evdev clients share a common waitgroup. On new input events, all
clients waiting on this waitgroup are woken up, even those filtering out
the events, possibly more than once per event. This leads to duplicated
and unwanted wakeups.

Split the shared waitgroup into per-client waitgroups for more
fine-grained wakeups.
Signed-off-by: Kenny Levinsen <kl@kl.wtf>
Link: https://lore.kernel.org/r/20200429184126.2155-1-kl@kl.wtfSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

With the new RMI4 F3A support, we're now able to enable full RMI4
support for this model.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20201005114919.371592-1-hdegoede@redhat.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

With the new RMI4 F3A support, we're now able to enable full RMI4
support for this model. We also tidy up the comments a bit, as the X1E
is essentially the same computer as the P1.
Acked-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20200930225046.173190-3-Jason@zx2c4.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

With the recent addition of the F3A support, we can now accept
bootloader v8, which will help support recent Thinkpads.
Acked-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20200930225046.173190-2-Jason@zx2c4.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

RMI4 F3A supports the touchpad GPIO function, it's designed to
support more GPIOs and used on newer touchpads. This patch adds
support of the touchpad buttons.
Signed-off-by: Vincent Huang <vincent.huang@tw.synaptics.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andrew Duggan <aduggan@synaptics.com>
Link: https://lore.kernel.org/r/20200930094147.635556-3-vincent.huang@tw.synaptics.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

f30_data in rmi_device_platform_data could be also referenced by RMI
function 3A, so rename it and the structure name to avoid confusion.
Signed-off-by: Vincent Huang <vincent.huang@tw.synaptics.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andrew Duggan <aduggan@synaptics.com>
Link: https://lore.kernel.org/r/20200930094147.635556-2-vincent.huang@tw.synaptics.comSigned-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.czSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

This patch adds dts bindings for the zinitix bt541 touchscreen.
Signed-off-by: Michael Srba <Michael.Srba@seznam.cz>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201001122949.16846-2-michael.srba@seznam.czSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Add a driver for joystick devices connected to ADC controllers
supporting the Industrial I/O subsystem.
Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
Tested-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20200927123302.31062-2-contact@artur-rojek.euSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Add documentation for the adc-joystick driver, used to provide support
for joysticks connected over ADC.
Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
Tested-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200927123302.31062-1-contact@artur-rojek.euSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

platform_get_irq() returns -ERRNO on error.  In such case comparison
to 0 would pass the check.

Fixes: e443631d ("Input: serio - add support for Alwinner A10/A20 PS/2 controller")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20200828145744.3636-4-krzk@kernel.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

platform_get_irq() returns -ERRNO on error.  In such case casting to
unsigned and comparing to 0 would pass the check.

Fixes: 7abf38d6 ("Input: twl4030-keypad - add device tree support")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200828145744.3636-3-krzk@kernel.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

platform_get_irq() returns -ERRNO on error.  In such case comparison
to 0 would pass the check.

Fixes: f3a1ba60 ("Input: omap4-keypad - use platform device helpers")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200828145744.3636-2-krzk@kernel.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

platform_get_irq() returns -ERRNO on error.  In such case comparison
to 0 would pass the check.

Fixes: 60214f05 ("Input: ep93xx_keypad - update driver to new core support")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200828145744.3636-1-krzk@kernel.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

In stmfts_sysfs_hover_enable_write(), we should check value and
sdata->hover_enabled is all true.

Fixes: 78bcac7b ("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.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Open/close and resume/suspend paths are very similar, let's factor out
common parts.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

If imx6ul_tsc_init() fails then we need to clean up the clocks.

I reversed the "if (input_dev->users) {" condition to make the code a
bit simpler.

Fixes: 6cc527b0 ("Input: imx6ul_tsc - propagate the errors")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200905124942.GC183976@mwandaSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Fixed typo for command from 0xE0 to 0xD0.

Fixes: cf520c64 ("Input: elants_i2c - provide an attribute to show calibration count")
Signed-off-by: Johnny Chuang <johnny.chuang.emc@gmail.com>
Link: https://lore.kernel.org/r/1600238783-32303-1-git-send-email-johnny.chuang.emc@gmail.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

This patch adds a new behavior to report touch major resolution
based on information provided by firmware.

In initial process, driver acquires touch information from touch ic.
It contains one byte about the resolution value of ABS_MT_TOUCH_MAJOR.
Touch driver will report touch major resolution by this information.
Signed-off-by: Johnny Chuang <johnny.chuang.emc@gmail.com>
Reviewed-by: Harry Cutts <hcutts@chromium.org>
Link: https://lore.kernel.org/r/1598581195-9874-1-git-send-email-johnny.chuang.emc@gmail.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

On an AMD chromebook, where the same I2C bus is shared by both Raydium
touchscreen and a trackpad device, it is observed that interleaving of
I2C messages when `raydium_i2c_read_message()` is called leads to the
Raydium touch IC reporting incorrect information. This is the sequence
that was observed to result in the above issue:

* I2C write to Raydium device for RM_CMD_BANK_SWITCH
* I2C write to trackpad device
* I2C read from trackpad device
* I2C write to Raydium device for setting address
* I2C read from Raydium device >>>> This provides incorrect
  information

This change adds a new helper function `raydium_i2c_xfer()` that
performs I2C transactions to the Raydium device. It uses the register
address to decide if RM_CMD_BANK_SWITCH header needs to be sent to the
device (i.e. if register address is greater than 255, then bank switch
header is sent before the rest of the transaction). Additionally, it
ensures that all the I2C operations performed as part of
`raydium_i2c_xfer()` are done as a single i2c_transfer. This
guarantees that no other transactions are initiated to any other
device on the same bus in between. Additionally,
`raydium_i2c_{send|read}*` functions are refactored to use this new
helper function.

Verified with the patch across multiple reboots (>100) that the
information reported by the Raydium  touchscreen device during probe
is correct.
Signed-off-by: Furquan Shaikh <furquan@google.com>
Link: https://lore.kernel.org/r/20200821024006.3399663-1-furquan@google.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>