Hi Nick, Many thanks for sending this upstream. Adding Guenter as also might be interested and some few questions regarding the driver structure.
Missatge de Nick Crews <[email protected]> del dia ds., 15 de des. 2018 a les 1:21: > > The Chromebook named wilco contains a different Embedded Controller > than the rest of the chromebook series, and thus the kernel requires > a different driver than the already existing and generalized > cros_ec_* drivers. Specifically, this driver adds support for getting > and setting the RTC on the EC, adding a binary sysfs attribute > that receives ACPI events from the EC, adding a binary sysfs > attribute to request telemetry data from the EC (useful for enterprise > applications), and adding normal sysfs attributes to get/set various > other properties on the EC. The core of the communication with the EC > is implemented in wilco_ec_mailbox.c, using a simple byte-level protocol > with a checksum, transmitted over an eSPI bus. For debugging purposes, > a raw attribute is also provided which can write/read arbitrary > bytes to/from the eSPI bus. > > We attempted to adhere to the sysfs principles of "one piece of data per > attribute" as much as possible, and mostly succeded. However, with the > wilco_ec_adv_power.h attributes, which deal with scheduling power usage, > we found it most elegant to bundle setting event times for an entire day > into a single attribute, so at most you are using attributes formatted > as "%d %d %d %d %d %d". With the telemetry attribute, we had to use a > binary attribute, instead of the preferable human-readable ascii, in > order to keep secure the information which is proprietary to the > enterprise service provider. This opaque binary data will be read and > sent using a proprietary daemon running on the OS. Finally, the > "version" attribute returns a formatted result that looks something > like: > > cat /sys/bus/platform/devices/GOOG000C\:00/version > Label : 95.00.06 > SVN Revision : 5960a.06 > Model Number : 08;8 > Build Date : 11/29/18 > > The RTC driver is exposed as a standard RTC class driver with > read/write functionality. > > For event notification, the Wilco EC can return extended events that > are not handled by standard ACPI objects. These events can > include hotkeys which map to standard functions like brightness > controls, or information about EC controlled features like the > charger or battery. These events are triggered with an > ACPI Notify(0x90) and the event data buffer is read through an ACPI > method provided by the BIOS which reads the event buffer from EC RAM. > These events are then processed, with hotkey events being sent > to the input subsystem and other events put into a queue which > can be read by a userspace daemon via a sysfs attribute. > > The rest of the attributes are categorized as either "properties" or > "legacy". "legacy" implies that the attribute existed on the EC before it > was modified for ChromeOS, and "properties" implies that the attribute > exposes functionality that was added to the EC specifically for > ChromeOS. They are mostly boolean flags or percentages. > > A full thread of the development of these patches can be found at > https://chromium-review.googlesource.com/c/1371034. This thread contains > comments and revisions that could be helpful in understanding how the > driver arrived at the state it is in now. The thread also contains some > ChromeOS specific patches that actually enable the driver. If you want > to test the patch yourself, you would have to install the ChromeOS SDK > and cherry pick in these patches. > > I also wrote some integration tests using the Tast testing framework that > ChromeOS uses. It would require a full ChromeOS SDK to actually run the > tests, but the source of the tests, written in Go, are useful for > understanding what the desired behavior is. You can view the tests here: > https://chromium-review.googlesource.com/c/1372575 > > This is still an initial version of the driver, and we are sending it > upstream for comments now, so that we can incorporate any requested > changes such that it eventually can be merged. Thank you for your > comments! > > > Duncan Laurie (6): > CHROMIUM: cros_ec: Remove cros_ec dependency in lpc_mec > CHROMIUM: wilco_ec: Add new driver for Wilco EC > CHROMIUM: wilco_ec: Add sysfs attributes > CHROMIUM: wilco_ec: Add support for raw commands in sysfs > CHROMIUM: wilco_ec: Add RTC class driver > CHROMIUM: wilco_ec: Add event handling > > Nick Crews (4): > CHROMIUM: wilco_ec: Move legacy attributes to separate file > CHROMIUM: wilco_ec: Add EC properties > CHROMIUM: wilco_ec: Add peakshift and adv_batt_charging > CHROMIUM: wilco_ec: Add binary telemetry attributes > > drivers/platform/chrome/Kconfig | 24 +- > drivers/platform/chrome/Makefile | 9 +- > drivers/platform/chrome/cros_ec_lpc_mec.c | 54 +- > drivers/platform/chrome/cros_ec_lpc_mec.h | 45 +- > drivers/platform/chrome/cros_ec_lpc_reg.c | 43 +- > drivers/platform/chrome/wilco_ec.h | 180 ++++++ > drivers/platform/chrome/wilco_ec_adv_power.c | 533 ++++++++++++++++++ > drivers/platform/chrome/wilco_ec_adv_power.h | 193 +++++++ > drivers/platform/chrome/wilco_ec_event.c | 343 +++++++++++ > drivers/platform/chrome/wilco_ec_legacy.c | 204 +++++++ > drivers/platform/chrome/wilco_ec_legacy.h | 96 ++++ > drivers/platform/chrome/wilco_ec_mailbox.c | 427 ++++++++++++++ > drivers/platform/chrome/wilco_ec_properties.c | 327 +++++++++++ > drivers/platform/chrome/wilco_ec_properties.h | 163 ++++++ > drivers/platform/chrome/wilco_ec_rtc.c | 163 ++++++ Shouldn't this go to the RTC subsystem? Not sure if there are more drivers that can go to a specific subsystem. > drivers/platform/chrome/wilco_ec_sysfs.c | 253 +++++++++ > drivers/platform/chrome/wilco_ec_sysfs_util.h | 47 ++ > drivers/platform/chrome/wilco_ec_telemetry.c | 66 +++ > drivers/platform/chrome/wilco_ec_telemetry.h | 42 ++ > 19 files changed, 3153 insertions(+), 59 deletions(-) Wow, seems that this is going to be big, might make sense add a wilco_ec subdirectory for all this? > create mode 100644 drivers/platform/chrome/wilco_ec.h > create mode 100644 drivers/platform/chrome/wilco_ec_adv_power.c > create mode 100644 drivers/platform/chrome/wilco_ec_adv_power.h > create mode 100644 drivers/platform/chrome/wilco_ec_event.c > create mode 100644 drivers/platform/chrome/wilco_ec_legacy.c > create mode 100644 drivers/platform/chrome/wilco_ec_legacy.h > create mode 100644 drivers/platform/chrome/wilco_ec_mailbox.c > create mode 100644 drivers/platform/chrome/wilco_ec_properties.c > create mode 100644 drivers/platform/chrome/wilco_ec_properties.h > create mode 100644 drivers/platform/chrome/wilco_ec_rtc.c > create mode 100644 drivers/platform/chrome/wilco_ec_sysfs.c > create mode 100644 drivers/platform/chrome/wilco_ec_sysfs_util.h > create mode 100644 drivers/platform/chrome/wilco_ec_telemetry.c > create mode 100644 drivers/platform/chrome/wilco_ec_telemetry.h > > -- > 2.20.0.405.gbc1bbc6f85-goog > Thanks, Enric
