Extract the EC feature-reading logic from cros_ec_check_features() into
cros_ec_read_features() helper function.

Currently, cros_ec_check_features() swallows command transfer errors. By
isolating the transaction logic into an explicit helper that returns the
actual transfer error code, subsequent callers (such as the cros_ec_dev
driver during device probing) can catch a read error.

Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
Acked-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://patch.msgid.link/20260608211518.2214740-2-akuchynski@chromium.org
Signed-off-by: Lee Jones <lee@kernel.org>

A race condition exists between the probe of cros-ec-sysfs and
cros-ec-sensorhub.

The `kb_wake_angle` attribute should only be visible if the sensor hub
detects two or more accelerometers.  If cros_ec_sysfs_probe() runs
before cros_ec_sensorhub_register() completes sensor enumeration, the
sysfs attributes are created while `has_kb_wake_angle` is still false,
hiding `kb_wake_angle` incorrectly.

Store the created attribute group pointer in `ec_dev->group`.  When
the sensor hub completes sensor enumeration, it checks for this group
and calls sysfs_update_group() to notify the sysfs core to re-evaluate
attribute visibility.  This ensures the `kb_wake_angle` attribute
visibility is correctly updated regardless of the driver probe order.

Co-developed-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Link: https://lore.kernel.org/r/20260407102615.1605317-1-tzungbi@kernel.org
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Introduce a `registered` flag to the `struct cros_ec_device` to allow
callers to determine if the device has been fully registered and is
ready for use.

This is a preparatory step to prevent race conditions where other drivers
might try to access the device before it is fully registered or after
it has been unregistered.

Link: https://lore.kernel.org/r/20250828083601.856083-5-tzungbi@kernel.org
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Move the common initialization from protocol device drivers into central
cros_ec_device_alloc().

This removes duplicated code from each driver's probe function.
The buffer sizes are now calculated once, using the maximum possible
overhead required by any of the transport protocols, ensuring the
allocated buffers are sufficient for all cases.

Link: https://lore.kernel.org/r/20250828083601.856083-3-tzungbi@kernel.org
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Only check EC for MKBP events when the ACPI notify value indicates the
notify is due to an MKBP host event. This reduces unnecessary queries to
the EC.

Notify value 0x80 is reserved for devices specific notifies. It is used
by many devices to indicate various events. It's only used by cros_ec
for MKBP events.

Signed-off-by: Rob Barnes <robbarnes@google.com>
Link: https://lore.kernel.org/r/20241218015759.3558830-1-robbarnes@google.com
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

There are EC devices, like FPMCU, that use RWSIG as a method of
authenticating RW section. After the authentication succeeds, EC device
waits some time before jumping to RW. EC can be probed before the jump,
which means there is a time window after jump to RW in which EC won't
respond, because it is not initialized. It can cause a communication
errors after probing.

To avoid such problems, send the RWSIG continue command first, which
skips waiting for the jump to RW. Send the command more times, to make
sure EC is ready in RW before the start of the actual probing process. If
a EC device doesn't support the RWSIG, it will respond with invalid
command error code and probing will continue as usual.

Signed-off-by: Dawid Niedzwiecki <dawidn@google.com>
Link: https://lore.kernel.org/r/20241206091514.2538350-2-dawidn@google.com
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Retrieving the supported versions of a command is a fairly common
operation. Provide a helper for it.

If the command is not supported at all the EC returns
-EINVAL/EC_RES_INVALID_PARAMS.

This error is translated into an empty version mask as that is easier to
handle for callers and they don't need to know about the error details.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20240630-cros_ec-charge-control-v5-3-8f649d018c52@weissschuh.net
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Upgrade EC_CMD_GET_NEXT_EVENT to version 3.

The max supported version will be v3. So, we speak v3 even if the EC
says it supports v4+.

Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Link: https://lore.kernel.org/r/20240604230837.2878737-1-dnojiri@chromium.org
[tzungbi: uint32_t -> u32 per suggested by checkpatch.pl]
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

To read from the EC memory different mechanism are possible.
ECs connected via LPC expose their memory via a ->cmd_readmem operation.
Other protocols require the usage of EC_CMD_READ_MEMMAP, which on the
other hand is not implemented by LPC ECs.

Provide a helper that automatically selects the correct mechanism.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20240529-cros_ec-hwmon-v4-1-5cdf0c5db50a@weissschuh.net
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

The 'outdata' is copied to the data buffer in cros_ec_cmd() before being
sent over to the EC. Mark the argument as const so that callers can pass
const pointers to this function and so that callers know the data won't
be modified.

Cc: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Prashant Malani <pmalani@chromium.org>
Link: https://lore.kernel.org/r/20231003003429.1378109-5-swboyd@chromium.org
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>