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chromium / chromiumos / third_party / usb / um_ppm / d4d74870807750b2ece64cc8e046d1cdd171be6d
commitd4d74870807750b2ece64cc8e046d1cdd171be6d[log] [tgz]
authorAbhishek Pandit-Subedi <abhishekpandit@google.com>Wed Dec 13 01:49:03 2023
committerGeorge Engelbrecht <engeg@google.com>Fri Jan 05 21:58:13 2024
treeb79313d80f8a7a5572c91333fe5703b67a3c2458
parent6dad6fa36663abb1c730405ac96e10d917b100be [diff]
Wire ppm to kernel driver

Add support for wiring um_ppm to the ucsi_um_test kernel driver. This
has been tested to properly communicate with the kernel driver but is
still not fully functional (verified up to Set Notifications Enable and
partial Ack_CC_CI).

BUG=b:303919041

Change-Id: Ia36b06bb84a075199a9047ff2367e2bcba87f7a2
9 files changed
tree: b79313d80f8a7a5572c91333fe5703b67a3c2458
  1. include/
  2. LICENSE
  3. main.c
  4. Makefile
  5. platform_usermode.c
  6. README.md
  7. rts5453.c
  8. rts5453.h
  9. smbus_usermode.c
  10. smbus_usermode.h
  11. um_ppm_chardev.c
  12. um_ppm_chardev.h
README.md

Usermode PPM implementation

Usermode UCSI PPM implementation for evaluation and testing usage. Try using this with the ucsi_um_test kernel driver.

Setup

For usermode implementations, we use libi2c and libgpiod to provide an smbus implementation. You will need the right libraries to build:

sudo apt-get install libi2c-dev libgpiod-dev

Architecture

┌─────────┐
│OPM      │
│kernel or│
│cli      │
└────┬────┘
     │
     │
     ▼          ┌───────────┐
 ┌────────┐     │ PD Driver │
 │        ├────►│           │
 │  PPM   │     ├───────────┤
 │        │     │           │
 └────────┘     │ I2C Driver│
                └───────────┘

The usermode ppm implementation consists of the PPM task, the PD driver and the I2C driver backing it. The OPM will either be a CLI (for locally triggering some functionality) or the ucsi_um_test kernel module.