kernel/include/linux/platform_data/cros_ec_proto.h, branch linux-5.10.y

platform/chrome: cros_ec: Use per-device lockdep key

2025-08-28T14:22:56Z

[ Upstream commit 961a325becd9a142ae5c8b258e5c2f221f8bfac8 ] Lockdep reports a bogus possible deadlock on MT8192 Chromebooks due to the following lock sequences: 1. lock(i2c_register_adapter) [1]; lock(&ec_dev->lock) 2. lock(&ec_dev->lock); lock(prepare_lock); The actual dependency chains are much longer. The shortened version looks somewhat like: 1. cros-ec-rpmsg on mtk-scp ec_dev->lock -> prepare_lock 2. In rt5682_i2c_probe() on native I2C bus: prepare_lock -> regmap->lock -> (possibly) i2c_adapter->bus_lock 3. In rt5682_i2c_probe() on native I2C bus: regmap->lock -> i2c_adapter->bus_lock 4. In sbs_probe() on i2c-cros-ec-tunnel I2C bus attached on cros-ec: i2c_adapter->bus_lock -> ec_dev->lock While lockdep is correct that the shared lockdep classes have a circular dependency, it is bogus because a) 2+3 happen on a native I2C bus b) 4 happens on the actual EC on ChromeOS devices c) 1 happens on the SCP coprocessor on MediaTek Chromebooks that just happens to expose a cros-ec interface, but does not have an i2c-cros-ec-tunnel I2C bus In short, the "dependencies" are actually on different devices. Setup a per-device lockdep key for cros_ec devices so lockdep can tell the two instances apart. This helps with getting rid of the bogus lockdep warning. For ChromeOS devices that only have one cros-ec instance this doesn't change anything. Also add a missing mutex_destroy, just to make the teardown complete. [1] This is likely the per I2C bus lock with shared lockdep class Signed-off-by: Chen-Yu Tsai Signed-off-by: Tzung-Bi Shih Link: https://lore.kernel.org/r/20230111074146.2624496-1-wenst@chromium.org Stable-dep-of: e23749534619 ("platform/chrome: cros_ec: Unregister notifier in cros_ec_unregister()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

platform/chrome: Re-introduce cros_ec_cmd_xfer and use it for ioctls

2022-06-09T08:21:14Z

[ Upstream commit 57b888ca2541785de2fcb90575b378921919b6c0 ] Commit 413dda8f2c6f ("platform/chrome: cros_ec_chardev: Use cros_ec_cmd_xfer_status helper") inadvertendly changed the userspace ABI. Previously, cros_ec ioctls would only report errors if the EC communication failed, and otherwise return success and the result of the EC communication. An EC command execution failure was reported in the EC response field. The above mentioned commit changed this behavior, and the ioctl itself would fail. This breaks userspace commands trying to analyze the EC command execution error since the actual EC command response is no longer reported to userspace. Fix the problem by re-introducing the cros_ec_cmd_xfer() helper, and use it to handle ioctl messages. Fixes: 413dda8f2c6f ("platform/chrome: cros_ec_chardev: Use cros_ec_cmd_xfer_status helper") Cc: Daisuke Nojiri Cc: Rob Barnes Cc: Rajat Jain Cc: Brian Norris Cc: Parth Malkan Reviewed-by: Daisuke Nojiri Reviewed-by: Brian Norris Signed-off-by: Guenter Roeck Signed-off-by: Tzung-Bi Shih Signed-off-by: Sasha Levin

platform/chrome: cros_ec_proto: Replace zero-length array with flexible-array member

2020-10-29T22:22:59Z

There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays Signed-off-by: Gustavo A. R. Silva

platform/chrome: cros_ec_proto: Do not export cros_ec_cmd_xfer()

2020-07-23T08:12:23Z

Now that all the remaining users of cros_ec_cmd_xfer() has been removed, make this function private to the cros_ec_proto module. Signed-off-by: Enric Balletbo i Serra

platform/chrome: cros_ec: Query EC protocol version if EC transitions between RO/RW

2020-02-11T09:32:54Z

RO and RW of EC may have different EC protocol version. If EC transitions between RO and RW, but AP does not reboot (this is true for fingerprint microcontroller / cros_fp, but not true for main ec / cros_ec), the AP still uses the protocol version queried before transition, which can cause problems. In the case of fingerprint microcontroller, this causes AP to send the wrong version of EC_CMD_GET_NEXT_EVENT to RO in the interrupt handler, which in turn prevents RO to clear the interrupt line to AP, in an infinite loop. Once an EC_HOST_EVENT_INTERFACE_READY is received, we know that there might have been a transition between RO and RW, so re-query the protocol. Signed-off-by: Yicheng Li Tested-by: Marek Szyprowski Reviewed-by: Gwendal Grignou Signed-off-by: Enric Balletbo i Serra

platform/chrome: cros_ec: Match implementation with headers

2020-02-03T16:14:50Z

The 'cros_ec' core driver is the common interface for the cros_ec transport drivers to do the shared operations to register, unregister, suspend, resume and handle_event. The interface is provided by including the header 'include/linux/platform_data/cros_ec_proto.h', however, instead of have the implementation of these functions in cros_ec_proto.c, it is in 'cros_ec.c', which is a different kernel module. Apart from being a bad practice, this can induce confusions allowing the users of the cros_ec protocol to call these functions. The register, unregister, suspend, resume and handle_event functions *should* only be called by the different transport drivers (i2c, spi, lpc, etc.), so make this a bit less confusing by moving these functions from the public in-kernel space to a private include in platform/chrome, and then, the interface for cros_ec module and for the cros_ec_proto module is clean. Signed-off-by: Enric Balletbo i Serra Signed-off-by: Benson Leung

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

2020-01-07T16:36:46Z

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 #include for a single include #include The changes to remove the cros_ec.h include were generated with the following shell script: git grep -l "" | xargs sed -i '//d' Signed-off-by: Enric Balletbo i Serra Acked-by: Lee Jones Acked-by: Alexandre Belloni Acked-by: Jonathan Cameron Acked-by: Sebastian Reichel Acked-by: Hans Verkuil

platform/chrome: cros_ec: handle MKBP more events flag

2019-11-21T10:23:15Z

The ChromeOS EC has support for signaling to the host that a single IRQ can serve multiple MKBP (Matrix KeyBoard Protocol) events. Doing this serves an optimization purpose, as it minimizes the number of round-trips into the interrupt handling machinery, and it proves beneficial to sensor timestamping as it keeps the desired synchronization of event times between the two processors. This patch adds kernel support for this EC feature, allowing the ec_irq to loop until all events have been served. Signed-off-by: Enrico Granata Signed-off-by: Gwendal Grignou Reviewed-by: Jonathan Cameron Acked-by: Lee Jones Signed-off-by: Enric Balletbo i Serra

platform/chrome: cros-ec: Record event timestamp in the hard irq

2019-11-21T10:23:14Z

To improve sensor timestamp precision, given EC and AP are in different time domains, the AP needs to try to record the exact moment an event was signalled to the AP by the EC as soon as possible after it happens. First thing in the hard irq is the best place for this. Signed-off-by: Gwendal Grignou Acked-by: Jonathan Cameron Acked-by: Lee Jones Signed-off-by: Enric Balletbo i Serra

mfd / platform / iio: cros_ec: Register sensor through sensorhub

2019-11-21T10:23:14Z

Remove the duplicated code in MFD, since MFD just registers cros-ec-sensorhub if at least one sensor is present. Change IIO cros-ec driver to get the pointer to the cros-ec-dev through cros-ec-sensorhub. Signed-off-by: Gwendal Grignou Acked-by: Jonathan Cameron Acked-by: Lee Jones Signed-off-by: Enric Balletbo i Serra