platform/chrome: cros_ec_sysfs: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230927081040.2198742-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

platform/chrome: use sysfs_emit_at() instead of scnprintf()

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: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20221205061042.1774769-1-tzungbi@kernel.org

platform/chrome: use sysfs_emit() instead of scnprintf()

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: ye xingchen <ye.xingchen@zte.com.cn>
Link: https://lore.kernel.org/r/202212021656040995199@zte.com.cn
[tzungbi: fixed the commit message.]
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

platform/chrome: cros_ec_sysfs: Add cold-ap-off to sysfs reboot.

Add cold-ap-off to ChromeOS EC sysfs reboot file option, corresponds to
the EC_REBOOT_COLD_AP_OFF flag, that will reset EC and keep AP off.

Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20201221041231.14516-2-pihsun@chromium.org

platform/chrome: Constify static attribute_group structs

The only usage of these is to print their name in a dev_err-message, and
to pass their address to sysfs_create_group() and sysfs_remove_group(),
both which takes pointers to const. Make them const to allow the compiler
to put them in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20210109001748.58036-1-rikard.falkeborn@gmail.com

platform/chrome: Use kobj_to_dev() instead of container_of()

Use kobj_to_dev() instead of container_of().

Signed-off-by: Wang Qing <wangqing@vivo.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

platform/chrome: cros_ec_sysfs: Report range of error codes from EC

Since commit c5cd2b47b203 ("platform/chrome: cros_ec_proto: Report command
not supported") we can no longer assume that cros_ec_cmd_xfer_status()
reports -EPROTO for all errors returned by the EC itself. A follow-up
patch will change cros_ec_cmd_xfer_status() to report additional errors
reported by the EC as distinguished Linux error codes.

Prepare for this change by always reporting both the Linux error code
and the EC error code in sysfs attributes.

Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Cc: Prashant Malani <pmalani@chromium.org>
Cc: Brian Norris <briannorris@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

platform/chrome: cros_ec_sysfs: Use cros_ec_cmd_xfer_status helper

This patch makes use of cros_ec_cmd_xfer_status() instead of
cros_ec_cmd_xfer(). In this case the change is trivial and the only
reason to do it is because we want to make cros_ec_cmd_xfer() a private
function for the EC protocol and let people only use the
cros_ec_cmd_xfer_status() to return Linux standard error codes.

Looking at the code I am even unsure that makes sense differentiate
these two errors but let's not change the behaviour for now.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Prashant Malani <pmalani@chromium.org>

cros_ec: treewide: Remove 'include/linux/mfd/cros_ec.h'

This header file now only includes the cros_ec_dev struct, however, is the
'include/linux/platform_data/cros_ec_proto.h' who contains the definition of
all the Chrome OS EC related structs. There is no reason to have a
separate include for this struct so move to the place where other
structs are defined. That way, we can remove the include itself, but also
simplify the common pattern

#include <linux/mfd/cros_ec.h>
#include <linux/platform_data/cros_ec_proto.h>

for a single include

#include <linux/platform_data/cros_ec_proto.h>

The changes to remove the cros_ec.h include were generated with the
following shell script:

git grep -l "<linux/mfd/cros_ec.h>" | xargs sed -i '/<linux\/mfd\/cros_ec.h>/d'

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

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>

platform/chrome: cros_ec: Make some symbols static

Fix sparse warning:

drivers/platform/chrome/cros_ec_debugfs.c:256:30: warning: symbol 'cros_ec_console_log_fops' was not declared. Should it be static?
drivers/platform/chrome/cros_ec_debugfs.c:265:30: warning: symbol 'cros_ec_pdinfo_fops' was not declared. Should it be static?
drivers/platform/chrome/cros_ec_lightbar.c:550:24: warning: symbol 'cros_ec_lightbar_attr_group' was not declared. Should it be static?
drivers/platform/chrome/cros_ec_sysfs.c:338:24: warning: symbol 'cros_ec_attr_group' was not declared. Should it be static?
drivers/platform/chrome/cros_ec_vbc.c:104:24: warning: symbol 'cros_ec_vbc_attr_group' was not declared. Should it be static?
drivers/platform/chrome/cros_ec_lpc.c:408:25: warning: symbol 'cros_ec_lpc_pm_ops' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

platform/chrome: cros_ec_sysfs: remove pr_fmt() define

This driver no longer has any pr_{level} messages. Remove the pr_fmt().

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>

platform/chrome: cros_ec_sysfs: switch to SPDX identifier

Adopt the SPDX license identifier headers to ease license compliance
management. Also change the description for one more appropriate.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>

mfd / platform: cros_ec: Move device sysfs attributes to its own driver

The entire way how cros debugfs attibutes are created is broken.
cros_ec_sysfs should be its own driver and its attributes should be
associated with the sysfs driver not the mfd driver.

The patch also adds the sysfs documentation.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

platform/chrome: Use to_cros_ec_dev more broadly

Move to_cros_ec_dev macro to cros_ec.h and use it when the private ec
object is needed from device object.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

platform/chrome: mfd/cros_ec_dev: Add sysfs entry to set keyboard wake lid angle

This adds a sysfs attribute (/sys/class/chromeos/cros_ec/kb_wake_angle)
used to set and get the keyboard wake lid angle. This attribute is
present only if 2 accelerometers are controlled by the EC.

This patch also moves the cros_ec features check before the device is
added so the features map obtained from the EC is ready on time.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Benson Leung <bleung@chromium.org>

platform/chrome: cros_ec_sysfs: use permission-specific DEVICE_ATTR variants

Use DEVICE_ATTR variants for read/write attributes. This simplifies the
source code, improves readbility, and reduces the chance of
inconsistencies.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

platform/chrome: cros_ec_sysfs: introduce to_cros_ec_dev define.

Add a define to get the cros_ec_dev from device and use it.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

platform/chrome: cros_ec_sysfs: Modify error handling

When accessing a sysfs attribute, if the EC command fails, -EPROTO is
now returned instead of an error message as it is unlikely an app is
parsing the error message to do something meaningful.
Also, this patch makes use of cros_ec_cmd_xfer_status() instead of
cros_ec_cmd_xfer() so an error message is printed in the syslog.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

cros_ec: fix nul-termination for firmware build info

As gcc-8 reports, we zero out the wrong byte:

drivers/platform/chrome/cros_ec_sysfs.c: In function 'show_ec_version':
drivers/platform/chrome/cros_ec_sysfs.c:190:12: error: array subscript 4294967295 is above array bounds of 'uint8_t[]' [-Werror=array-bounds]

This changes the code back to what it did before changing to a
zero-length array structure.

Fixes: a841178445bb ("mfd: cros_ec: Use a zero-length array for command data")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benson Leung <bleung@chromium.org>

cros_ec: Move cros_ec_dev module to drivers/mfd

The cros_ec_dev module is responsible for registering the MFD devices
attached to the ChromeOS EC. This patch moves this module to drivers/mfd
so calls to mfd_add_devices() are not done from outside the MFD subtree
anymore.

Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

cros_ec: Split cros_ec_devs module

This patch splits the cros_ec_devs module in two parts with a
cros_ec_dev module responsible for handling MFD devices registration and
a cros_ec_ctl module responsible for handling the various user-space
interfaces.

For consistency purpose, the driver name for the cros_ec_dev module is
now cros-ec-dev instead of cros-ec-ctl.

In the next commit, the new cros_ec_dev module will be moved to the MFD
subtree so mfd_add_devices() calls are not done from outside MFD.

Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: cros_ec: Support multiple EC in a system

Chromebooks can have more than one Embedded Controller so the
cros_ec device id has to be incremented for each EC registered.

Add a new structure to represent multiple EC as different char
devices (e.g: /dev/cros_ec, /dev/cros_pd). It connects to
cros_ec_device and allows sysfs inferface for cros_pd.

Also reduce number of allocated objects, make chromeos sysfs
class object a static and add refcounting to prevent object
deletion while command is in progress.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: cros_ec: Use a zero-length array for command data

Commit 1b84f2a4cd4a ("mfd: cros_ec: Use fixed size arrays to transfer
data with the EC") modified the struct cros_ec_command fields to not
use pointers for the input and output buffers and use fixed length
arrays instead.

This change was made because the cros_ec ioctl API uses that struct
cros_ec_command to allow user-space to send commands to the EC and
to get data from the EC. So using pointers made the API not 64-bit
safe. Unfortunately this approach was not flexible enough for all
the use-cases since there may be a need to send larger commands
on newer versions of the EC command protocol.

So to avoid to choose a constant length that it may be too big for
most commands and thus wasting memory and CPU cycles on copy from
and to user-space or having a size that is too small for some big
commands, use a zero-length array that is both 64-bit safe and
flexible. The same buffer is used for both output and input data
so the maximum of these values should be used to allocate it.

Suggested-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

platform/chrome: Create sysfs attributes for the ChromeOS EC

This adds the first few sysfs attributes for the Chrome OS EC. These
controls are made available under /sys/devices/virtual/chromeos/cros_ec

flashinfo - display current flash info
reboot - tell the EC to reboot in various ways
version - information about the EC software and hardware

Future changes will build on this to add additional controls.

From a root shell, you should be able to do things like this:

cd /sys/devices/virtual/chromeos/cros_ec
cat flashinfo
cat version
echo rw > reboot
cat version
echo ro > reboot
cat version
echo rw > reboot
cat version
echo cold > reboot

That last command will reboot the AP too.

Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-by: Olof Johansson <olofj@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Olof Johansson <olof@lixom.net>