From: Matthew Blecker <matthewb@xxxxxxxxxxxx> This patch adds i2c-pseudo, a module that provides I2C adapters backed by userspace programs. This allows for userspace implementations of functionality such as tunneling I2C through another communication channel, or mocking of real I2C devices whose behavior cannot be modeled with i2c-stub. Module naming: A pseudo I2C adapter is analogous to a pseudo terminal. In the Chromium OS ecosystem we are using this for a userspace I2C adapter built on top of an existing userspace I2C-over-USB implementation used with embedded debug devices that act as I2C master to a device under test (DUT). This arrangement is used for interacting with I2C slaves on the DUT, particularly for transferring firmware to an embedded controller IC which receives programming via I2C. That I2C pseudo controller implementation is here: https://chromium.googlesource.com/chromiumos/third_party/hdctools/+/refs/heads/master/servo/interface/i2c_pseudo.py --- Changelog v2: - Fix ARCH=um compilation error from non-const strlen("literal"). Matthew Blecker (1): i2c: Add new i2c-pseudo driver for userspace I2C adapters. .../i2c/pseudo-controller-interface.rst | 305 ++ drivers/i2c/Kconfig | 17 +- drivers/i2c/Makefile | 1 + drivers/i2c/i2c-pseudo.c | 3200 +++++++++++++++++ 4 files changed, 3522 insertions(+), 1 deletion(-) create mode 100644 Documentation/i2c/pseudo-controller-interface.rst create mode 100644 drivers/i2c/i2c-pseudo.c
