extcon: usbc-cros-ec: Use struct_size() helper in kzalloc()

Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows that,
in the worst scenario, could lead to heap overflows.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

mfd / platform: cros_ec: Reorganize platform and mfd includes

There is a bit of mess between cros-ec mfd includes and platform
includes. For example, we have a linux/mfd/cros_ec.h include that
exports the interface implemented in platform/chrome/cros_ec_proto.c. Or
we have a linux/mfd/cros_ec_commands.h file that is non related to the
multifunction device (in the sense that is not exporting any function of
the mfd device). This causes crossed includes between mfd and
platform/chrome subsystems and makes the code difficult to read, apart
from creating 'curious' situations where a platform/chrome driver includes
a linux/mfd/cros_ec.h file just to get the exported functions that are
implemented in another platform/chrome driver.

In order to have a better separation on what the cros-ec multifunction
driver does and what the cros-ec core provides move and rework the
affected includes doing:

- Move cros_ec_commands.h to include/linux/platform_data/cros_ec_commands.h
- Get rid of the parts that are implemented in the platform/chrome/cros_ec_proto.c
driver from include/linux/mfd/cros_ec.h to a new file
include/linux/platform_data/cros_ec_proto.h
- Update all the drivers with the new includes, so
- Drivers that only need to know about the protocol include
- linux/platform_data/cros_ec_proto.h
- linux/platform_data/cros_ec_commands.h
- Drivers that need to know about the cros-ec mfd device also include
- linux/mfd/cros_ec.h

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Series changes: 3
- Fix dereferencing pointer to incomplete type 'struct cros_ec_dev' (lkp)
Signed-off-by: Lee Jones <lee.jones@linaro.org>

extcon: usbc-cros-ec: Switch to SPDX identifier.

Adopt the SPDX license identifier headers to ease license compliance
management.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

extcon: usbc-cros-ec: Make license text and module license match.

The license text is specifying "GPLv2" but the MODULE_LICENSE is set to
GPL which means GNU Public License v2 or later. When MODULE_LICENSE and
boiler plate does not match, go for boiler plate license.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

extcon: usbc-cros-ec: add support to notify USB type cables.

Extend the driver to notify host and device type cables and the presence
of power.

Signed-off-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

extcon: Split out extcon header file for consumer and provider device

The extcon has two type of extcon devices as following.
- 'extcon provider deivce' adds new extcon device and detect the
state/properties of external connector. Also, it notifies the
state/properties to the extcon consumer device.
- 'extcon consumer device' gets the change state/properties
from extcon provider device.
Prior to that, include/linux/extcon.h contains all exported API for
both provider and consumer device driver. To clarify the meaning of
header file and to remove the wrong use-case on consumer device,
this patch separates into extcon.h and extcon-provider.h.

[Description for include/linux/{extcon.h|extcon-provider.h}]
- extcon.h includes the extcon API and data structure for extcon consumer
device driver. This header file contains the following APIs:
: Register/unregister the notifier to catch the change of extcon device
: Get the extcon device instance
: Get the extcon device name
: Get the state of each external connector
: Get the property value of each external connector
: Get the property capability of each external connector

- extcon-provider.h includes the extcon API and data structure for extcon
provider device driver. This header file contains the following APIs:
: Include 'include/linux/extcon.h'
: Allocate the memory for extcon device instance
: Register/unregister extcon device
: Set the state of each external connector
: Set the property value of each external connector
: Set the property capability of each external connector

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>

extcon: cros-ec: Fix a potential NULL pointer dereference

Return -ENOMEM in case of memory allocation failure. This avoids a NULL
pointer dereference.

Fixes: c69831666109 ("extcon: cros-ec: Add extcon-cros-ec driver to support display out")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

extcon: cros-ec: Add extcon-cros-ec driver to support display out

This is the driver for the USB Type C cable detection mechanism
built into the ChromeOS Embedded Controller on systems that
have USB Type-C ports.

At present, this allows for the presence of display out, but in
future, it may also be used to notify host and device type cables
and the presence of power.

Signed-off-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Chanwoo Choi <cw00.chio@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>