platform/chrome/wilco_ec: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

This is less verbose.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/898d9aa181a84f1d17725ca047004bad532c37e9.1702745959.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

platform/chrome/wilco_ec: telemetry: 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/20230927081040.2198742-13-u.kleine-koenig@pengutronix.de
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

drivers: remove struct module * setting from struct class

There is no need to manually set the owner of a struct class, as the
registering function does it automatically, so remove all of the
explicit settings from various drivers that did so as it is unneeded.

This allows us to remove this pointer entirely from this structure going
forward.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

platform/chrome: wilco_ec: convert stream-like files from nonseekable_open -> stream_open

Eliminate the following coccicheck warning:
./drivers/platform/chrome/wilco_ec/telemetry.c:259:1-17: WARNING:
telem_fops: .read() and .write() have stream semantic; safe to change
nonseekable_open -> stream_open.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/1612688918-63132-1-git-send-email-yang.lee@linux.alibaba.com

platform/chrome: wilco_ec: Add newlines to printks

printk messages all require newlines, or it looks very odd in the log
when messages are not on different lines. Add them.

Cc: Nick Crews <ncrews@chromium.org>
Cc: Daniel Campello <campello@chromium.org>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

platform/chrome: wilco_ec: fix use after free issue

This is caused by dereferencing 'dev_data' after put_device() in
the telem_device_remove() function.
This patch just moves the put_device() down a bit to avoid this
issue.

Fixes: 1210d1e6bad1 ("platform/chrome: wilco_ec: Add telemetry char device interface")
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Cc: Benson Leung <bleung@chromium.org>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Cc: Nick Crews <ncrews@chromium.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

platform/chrome: wilco_ec: Add batt_ppid_info command to telemetry driver

Add the GET_BATT_PPID_INFO=0x8A command to the allowlist of accepted
telemetry commands. In addition, since this new command requires
verifying the contents of some of the arguments, I also restructure
the request to use a union of the argument structs. Also, zero out the
request buffer before each request, and change "whitelist" to
"allowlist".

Signed-off-by: Nick Crews <ncrews@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

platform/chrome: wilco_ec: Add telemetry char device interface

The Wilco Embedded Controller is able to send telemetry data
which is useful for enterprise applications. A daemon running on
the OS sends a command to the EC via a write() to a char device,
and can read the response with a read(). The write() request is
verified by the driver to ensure that it is performing only one
of the whitelisted commands, and that no extraneous data is
being transmitted to the EC. The response is passed directly
back to the reader with no modification.

The character device will appear as /dev/wilco_telemN, where N
is some small non-negative integer, starting with 0. Only one
process may have the file descriptor open at a time. The calling
userspace program needs to keep the device file descriptor open
between the calls to write() and read() in order to preserve the
response. Up to 32 bytes will be available for reading.

For testing purposes, try requesting the EC's firmware build
date, by sending the WILCO_EC_TELEM_GET_VERSION command with
argument index=3. i.e. write [0x38, 0x00, 0x03]
to the device node. An ASCII string of the build date is
returned.

Signed-off-by: Nick Crews <ncrews@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>