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chromium / chromiumos / third_party / usb / um_ppm / eaa368a15a6ae8ea5df12aefda2ef22efd2a86aa
commiteaa368a15a6ae8ea5df12aefda2ef22efd2a86aa[log] [tgz]
authorPavan Holla <pholla@chromium.org>Wed Jan 31 18:07:45 2024
committerPavan Holla <pholla@chromium.org>Wed Jan 31 18:58:56 2024
tree4dcabfd7d3478795c86923d09b7a23139f30bd07
parenta9b9466165e9c1c761d56eba838bfbe800bab44c [diff]
ppm_common: Clear prior CCI on error

BUG=b:319124783
TEST=make local_tests; um_ppm -v -b 22 -g 1 -l 2 -k /dev/ucsi_um_test-0

Change-Id: Ida277bacff08f03574407bb207de5e6c2fd1c437
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/usb/um_ppm/+/5251769
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@google.com>
Tested-by: Pavan Holla <pholla@google.com>
2 files changed
tree: 4dcabfd7d3478795c86923d09b7a23139f30bd07
  1. include/
  2. test/
  3. .gitignore
  4. LICENSE
  5. main.c
  6. Makefile
  7. platform_usermode.c
  8. ppm_common.c
  9. ppm_common.h
  10. README.md
  11. rts5453.c
  12. rts5453.h
  13. rts5453_usermode.c
  14. smbus_usermode.c
  15. smbus_usermode.h
  16. um_ppm_chardev.c
  17. 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.