Hello, The mainline ChromeOS Embedded Controller (EC) driver is still missing some features that are present in the downstream ChromiumOS tree. These are: - User-space device interface - Low Pin Count (LPC) interface - Access to vboot context stored on a block device - Access to vboot context stored on EC's nvram - Power Delivery Device - Support for multiple EC in a system This is a second version of a series that adds support for the first of these missing features: the ChromeOS EC character device driver that provides the interface used by user-space to access the EC. The support patches were taken from the downstream ChromiumOS 3.14 kernel tree with fixes and cleanups squashed to have a minimal patch-set. The version of the ChromeOS EC chardev driver in this series still does not reflect the latest one that is in the downstream ChromiumOS 3.14 kernel but makes the delta shorter. Following patches will add the remaining missing features until both trees are in sync. I preferred to first add the initial support and then adding the other features to both maintain the original patch history in the downstream kernel and so preserve the patch authorship and also make the diff to have a working cros user-space interface smaller. Version 1 of this series was [0] and added the Chrome EC chardev driver and the sysfs interface to drivers/mfd since that is what is done in the downstream ChromiumOS kernel but Lee Jones asked to find a better place since those are not really multi-function device drivers. So this version places them under drivers/platform/chrome since MAINTAINERS says that this sub-directory is "CHROME HARDWARE PLATFORM SUPPORT" which seems a good fit. A big change in this version is that the ioctl API is modified to make it 64-bit safe and compatible with both 64 and 32 bit user-space binaries. The data structures passed as arguments to ioctl commands had pointers fields and these have different byte boundaries alignment requirement so the previous version had a compat ioctl interface. The feedback was that this had to be avoided since this was a new ioctl API so the pointers fields were replaced with a set of fixed-size arrays to be used instead. This has the drawback that more data could be used and copied between user and kernel space so feedback is welcomed if there is a better approach to solve this kind of issues. The patches were tested on an Exynos5420 Peach Pit Chromebook usig a modified ectool [1] adapted to use the new ioctl API. I don't have access to a Pixel Chromebook so testing of the sysfs lightbar interface is highly appreciated. The series is composed of the following patches: Bill Richardson (3): platform/chrome: Add Chrome OS EC userspace device interface platform/chrome: Create sysfs attributes for the ChromeOS EC. platform/chrome: Expose Chrome OS Lightbar to users Javier Martinez Canillas (3): mfd: cros_ec: Use fixed size arrays to transfer data with the EC mfd: cros_ec: Add char dev and virtual dev pointers mfd: cros_ec: Instantiate ChromeOS EC character device Documentation/ioctl/ioctl-number.txt | 1 + drivers/i2c/busses/i2c-cros-ec-tunnel.c | 51 +--- drivers/input/keyboard/cros_ec_keyb.c | 13 +- drivers/mfd/cros_ec.c | 19 +- drivers/platform/chrome/Kconfig | 14 +- drivers/platform/chrome/Makefile | 2 + drivers/platform/chrome/cros_ec_dev.c | 274 ++++++++++++++++++++++ drivers/platform/chrome/cros_ec_dev.h | 53 +++++ drivers/platform/chrome/cros_ec_lightbar.c | 363 +++++++++++++++++++++++++++++ drivers/platform/chrome/cros_ec_sysfs.c | 271 +++++++++++++++++++++ include/linux/mfd/cros_ec.h | 23 +- 11 files changed, 1022 insertions(+), 62 deletions(-) create mode 100644 drivers/platform/chrome/cros_ec_dev.c create mode 100644 drivers/platform/chrome/cros_ec_dev.h create mode 100644 drivers/platform/chrome/cros_ec_lightbar.c create mode 100644 drivers/platform/chrome/cros_ec_sysfs.c Patch #1 modified the struct cros_ec_command structure so it can be used as an ioctl argument and be 64 and 32 bit safe and patch #2 adds fields to the struct cros_ec_device that will be needed by the EC chardev driver. Patch #3 adds the ChromeOS chardev driver and patch #4 instantiates it from the mfd cros_ec driver. Patch #5 and Patch #6 exposes sysfs attributes that can be used by user space programs to get information and control the ChromeOS EC. The patches must be applied together and in that order due dependencies. Best regards, Javier [0]: https://lkml.org/lkml/2014/11/17/429 [1]: git://git.collabora.co.uk/git/user/javier/ec.git mainline-ioctl -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
