[RFC PATCH v2 0/5] rust/hw: Add the I2C and the first GPIO device

[chenmiao]

We have implemented I2C and the first GPIO device in Rust for QEMU.
Additionally, in the respective patches, we have shared our insights and
experiences regarding the use of Rust for device modeling within QEMU.

1. The first patch implements the BusState for the I2CBus infrastructure.
2. The second patch implements the I2CBus and I2CSlave infrastructure, along
with a discussion of the challenges encountered during the implementation.
3. The third patch moves the struct definition of the PCF8574 to the
corresponding header file.
4. The fourth patch provides a set of necessary helper functions for the PCF8574
GPIO device.
5. The fifth patch implements the PCF8574 GPIO device, along with a discussion
of the issues and considerations addressed during the implementation.

Regarding this series of patches, we have found that Rust for QEMU is indeed
still not mature enough and requires continuous iteration. Additionally, the
lack of basic documentation also needs to be addressed. In this regard, I hope
our team(HUST OpenAtom Open Source Club) can contribute to the documentation
efforts for Rust for QEMU.

Link: https://groups.google.com/g/hust-os-kernel-patches/c/z7vHWg3xvDc

Signed-off-by: Chao Liu <chao...@openatom.club>
Signed-off-by: Chen Miao <chen...@openatom.club>

---
Changes in V2:
- According to Zhao's suggestions, some modifications were made to the first
and second patches respectively, such as changing some bus names, adding
some Safety comments, and adding callbacks for I2CSlave.

chenmiao (5):
rust/hw/core: Add the BusState of rust version
rust/hw/core: Add rust bindings/funcs for i2c bus
hw/gpio: Move the pcf8574 struct to header
rust/hw/core: Provide some interfaces for the GPIO device
rust/hw/gpio: Add the the first gpio device pcf8574

hw/gpio/Kconfig | 5 +
hw/gpio/meson.build | 2 +-
hw/gpio/pcf8574.c | 32 --
include/hw/gpio/pcf8574.h | 36 +++
rust/Cargo.lock | 21 +-
rust/Cargo.toml | 1 +
rust/hw/Kconfig | 1 +
rust/hw/core/meson.build | 2 +
rust/hw/core/src/bus.rs | 55 ++++
rust/hw/core/src/i2c.rs | 421 +++++++++++++++++++++++++++
rust/hw/core/src/irq.rs | 6 +-
rust/hw/core/src/lib.rs | 6 +
rust/hw/core/src/qdev.rs | 12 +-
rust/hw/core/wrapper.h | 1 +
rust/hw/gpio/Kconfig | 2 +
rust/hw/gpio/meson.build | 1 +
rust/hw/gpio/pcf8574/Cargo.toml | 31 ++
rust/hw/gpio/pcf8574/build.rs | 1 +
rust/hw/gpio/pcf8574/meson.build | 50 ++++
rust/hw/gpio/pcf8574/src/bindings.rs | 29 ++
rust/hw/gpio/pcf8574/src/device.rs | 180 ++++++++++++
rust/hw/gpio/pcf8574/src/lib.rs | 4 +
rust/hw/gpio/pcf8574/wrapper.h | 51 ++++
rust/hw/meson.build | 1 +
24 files changed, 913 insertions(+), 38 deletions(-)
create mode 100644 rust/hw/core/src/bus.rs
create mode 100644 rust/hw/core/src/i2c.rs
create mode 100644 rust/hw/gpio/Kconfig
create mode 100644 rust/hw/gpio/meson.build
create mode 100644 rust/hw/gpio/pcf8574/Cargo.toml
create mode 120000 rust/hw/gpio/pcf8574/build.rs
create mode 100644 rust/hw/gpio/pcf8574/meson.build
create mode 100644 rust/hw/gpio/pcf8574/src/bindings.rs
create mode 100644 rust/hw/gpio/pcf8574/src/device.rs
create mode 100644 rust/hw/gpio/pcf8574/src/lib.rs
create mode 100644 rust/hw/gpio/pcf8574/wrapper.h

--
2.43.0

[chenmiao]

[Dan Carpenter]

You're going to need to send patches as a thread. I use something like
this (it's part of a script):

COVER="--cover-letter"
git format-patch --thread=shallow $COVER --output-directory=$DIR --from="$MY_FULL_EMAIL" --quiet -4

regards,
dan carpenter

[Chen Miao]

Hi Dan,

Thanks for your reply. I remember it and will try it when I send to the
upstream of qemu later.

Thanks,

Chen Miao

[chenmiao]

- While we were making changes to the first PATCH, Chao Liu pointed out that
the realize function was unnecessary in the bus. After discussion, we
removed the bus::realize function. Since no other components are currently
using the bus, we added a TODO comment for clarification.

chenmiao (5):
rust/hw/core: Add the BusState of rust version
rust/hw/core: Add rust bindings/funcs for i2c bus
hw/gpio: Move the pcf8574 struct to header
rust/hw/core: Provide some interfaces for the GPIO device
rust/hw/gpio: Add the the first gpio device pcf8574

hw/gpio/Kconfig | 5 +
hw/gpio/meson.build | 2 +-
hw/gpio/pcf8574.c | 32 --
include/hw/gpio/pcf8574.h | 36 +++
rust/Cargo.lock | 21 +-
rust/Cargo.toml | 1 +
rust/hw/Kconfig | 1 +
rust/hw/core/meson.build | 2 +

rust/hw/core/src/bus.rs | 44 +++

rust/hw/core/src/i2c.rs | 421 +++++++++++++++++++++++++++
rust/hw/core/src/irq.rs | 6 +-
rust/hw/core/src/lib.rs | 6 +
rust/hw/core/src/qdev.rs | 12 +-
rust/hw/core/wrapper.h | 1 +
rust/hw/gpio/Kconfig | 2 +
rust/hw/gpio/meson.build | 1 +
rust/hw/gpio/pcf8574/Cargo.toml | 31 ++
rust/hw/gpio/pcf8574/build.rs | 1 +
rust/hw/gpio/pcf8574/meson.build | 50 ++++
rust/hw/gpio/pcf8574/src/bindings.rs | 29 ++
rust/hw/gpio/pcf8574/src/device.rs | 180 ++++++++++++
rust/hw/gpio/pcf8574/src/lib.rs | 4 +
rust/hw/gpio/pcf8574/wrapper.h | 51 ++++
rust/hw/meson.build | 1 +

24 files changed, 902 insertions(+), 38 deletions(-)