04a8bdd135
This patch does following: 1. Adds a new cros-ec-uart driver. This driver can send EC requests on UART and process response packets received on UART transport. 2. Once probed, this driver will initialize the serdev device based on the underlying information in the ACPI resource. After serdev device properties are set, this driver will register itself cros-ec. 3. High level driver can use this implementation to talk to ChromeOS Embedded Controller device in case it supports UART as transport. 4. When cros-ec driver initiates a request packet, outgoing message is processed in buffer and sent via serdev. Once bytes are sent, driver enables a wait_queue. 5. Since ChromeOS EC device sends response asynchronously, AP's TTY driver accumulates response bytes and calls the registered callback. TTY driver can send multiple callback for bytes ranging from 1 to MAX bytes supported by EC device. 6. Driver waits for EC_MSG_DEADLINE_MS to collect and process received bytes. It wakes wait_queue if expected bytes are received or else wait_queue timeout. Based on the error condition, driver returns data_len or error to cros_ec. Signed-off-by: Bhanu Prakash Maiya <bhanumaiya@chromium.org> Co-developed-by: Mark Hasemeyer <markhas@chromium.org> Signed-off-by: Mark Hasemeyer <markhas@chromium.org> Reviewed-by: Prashant Malani <pmalani@chromium.org> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org> Link: https://lore.kernel.org/r/20221227123212.v13.1.If7926fcbad397bc6990dd725690229bed403948c@changeid
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.