From: chenmiao <[email protected]> After implementing the I2CBus and I2CSlave, we proceeded to implement a basic GPIO device — the PCF8574 — which depends on I2CSlave.
This patch must depend on the below link to compile normally: https://lists.nongnu.org/archive/html/qemu-devel/2025-10/msg07356.html At present, I have summarized the general workflow for device modeling in Rust as follows: 1. Modify the configuration under hw/deviceto distinguish between C and Rust versions. 2. Create a device crate under rust/hw. 3. Add (or copy) the necessary wrappers, build.rs, and bindings. 4. Begin the device modeling process. 5. Construct the corresponding structures in Rust that mirror those in C, especially for “members that may change”. 6. Referencing the C implementation, define initialization functions and establish parent-class relationships for the Rust structure. 7. Set up ObjectImpl, DeviceImpl, and ResettablePhasesImpl. 8. Configure vmstate. 9. Implement other functional methods. Signed-off-by: Chen Miao <[email protected]> --- hw/gpio/Kconfig | 5 + hw/gpio/meson.build | 2 +- rust/Cargo.lock | 18 +++- rust/Cargo.toml | 1 + rust/hw/Kconfig | 1 + rust/hw/gpio/Kconfig | 2 + rust/hw/gpio/meson.build | 1 + rust/hw/gpio/pcf8574/Cargo.toml | 28 +++++ rust/hw/gpio/pcf8574/meson.build | 37 +++++++ rust/hw/gpio/pcf8574/src/lib.rs | 178 +++++++++++++++++++++++++++++++ rust/hw/meson.build | 1 + 11 files changed, 272 insertions(+), 2 deletions(-) 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 100644 rust/hw/gpio/pcf8574/meson.build create mode 100644 rust/hw/gpio/pcf8574/src/lib.rs diff --git a/hw/gpio/Kconfig b/hw/gpio/Kconfig index a209294c20..1be534aaf6 100644 --- a/hw/gpio/Kconfig +++ b/hw/gpio/Kconfig @@ -27,6 +27,11 @@ config PCA9554 config PCF8574 bool depends on I2C + select PCF8574_C if !HAVE_RUST + select X_PCF8574_RUST if HAVE_RUST + +config PCF8574_C + bool config ZAURUS_SCOOP bool diff --git a/hw/gpio/meson.build b/hw/gpio/meson.build index 74840619c0..9e4b1a8fd7 100644 --- a/hw/gpio/meson.build +++ b/hw/gpio/meson.build @@ -17,4 +17,4 @@ system_ss.add(when: 'CONFIG_RASPI', if_true: files( system_ss.add(when: 'CONFIG_STM32L4X5_SOC', if_true: files('stm32l4x5_gpio.c')) system_ss.add(when: 'CONFIG_ASPEED_SOC', if_true: files('aspeed_gpio.c')) system_ss.add(when: 'CONFIG_SIFIVE_GPIO', if_true: files('sifive_gpio.c')) -system_ss.add(when: 'CONFIG_PCF8574', if_true: files('pcf8574.c')) +system_ss.add(when: 'CONFIG_PCF8574_C', if_true: files('pcf8574.c')) diff --git a/rust/Cargo.lock b/rust/Cargo.lock index 0c1df625df..2db2f70e8a 100644 --- a/rust/Cargo.lock +++ b/rust/Cargo.lock @@ -1,6 +1,6 @@ # This file is automatically @generated by Cargo. # It is not intended for manual editing. -version = 3 +version = 4 [[package]] name = "anyhow" @@ -204,6 +204,22 @@ dependencies = [ "util", ] +[[package]] +name = "pcf8574" +version = "0.1.0" +dependencies = [ + "bits", + "bql", + "common", + "glib-sys", + "hwcore", + "migration", + "qom", + "system", + "trace", + "util", +] + [[package]] name = "pkg-config" version = "0.3.32" diff --git a/rust/Cargo.toml b/rust/Cargo.toml index 783e626802..6a17eefe49 100644 --- a/rust/Cargo.toml +++ b/rust/Cargo.toml @@ -10,6 +10,7 @@ members = [ "system", "hw/core", "hw/char/pl011", + "hw/gpio/pcf8574", "hw/timer/hpet", "trace", "util", diff --git a/rust/hw/Kconfig b/rust/hw/Kconfig index 36f92ec028..ba1297ca2d 100644 --- a/rust/hw/Kconfig +++ b/rust/hw/Kconfig @@ -1,3 +1,4 @@ # devices Kconfig source char/Kconfig +source gpio/Kconfig source timer/Kconfig diff --git a/rust/hw/gpio/Kconfig b/rust/hw/gpio/Kconfig new file mode 100644 index 0000000000..c47aa76f14 --- /dev/null +++ b/rust/hw/gpio/Kconfig @@ -0,0 +1,2 @@ +config X_PCF8574_RUST + bool diff --git a/rust/hw/gpio/meson.build b/rust/hw/gpio/meson.build new file mode 100644 index 0000000000..908991ad13 --- /dev/null +++ b/rust/hw/gpio/meson.build @@ -0,0 +1 @@ +subdir('pcf8574') diff --git a/rust/hw/gpio/pcf8574/Cargo.toml b/rust/hw/gpio/pcf8574/Cargo.toml new file mode 100644 index 0000000000..a3bd82f93d --- /dev/null +++ b/rust/hw/gpio/pcf8574/Cargo.toml @@ -0,0 +1,28 @@ +[package] +name = "pcf8574" +version = "0.1.0" +authors = ["Chen Miao <[email protected]>"] +description = "pcf8574 device model for QEMU" +resolver = "2" +publish = false + +edition.workspace = true +homepage.workspace = true +license.workspace = true +repository.workspace = true +rust-version.workspace = true + +[dependencies] +glib-sys.workspace = true +bits = { path = "../../../bits" } +common = { path = "../../../common" } +util = { path = "../../../util" } +bql = { path = "../../../bql" } +migration = { path = "../../../migration" } +qom = { path = "../../../qom" } +system = { path = "../../../system" } +hwcore = { path = "../../../hw/core" } +trace = { path = "../../../trace" } + +[lints] +workspace = true diff --git a/rust/hw/gpio/pcf8574/meson.build b/rust/hw/gpio/pcf8574/meson.build new file mode 100644 index 0000000000..f0b7f9e687 --- /dev/null +++ b/rust/hw/gpio/pcf8574/meson.build @@ -0,0 +1,37 @@ +# TODO: Remove this comment when the clang/libclang mismatch issue is solved. +# +# Rust bindings generation with `bindgen` might fail in some cases where the +# detected `libclang` does not match the expected `clang` version/target. In +# this case you must pass the path to `clang` and `libclang` to your build +# command invocation using the environment variables CLANG_PATH and +# LIBCLANG_PATH +_libpcf8574_rs = static_library( + 'pcf8574', + structured_sources( + [ + 'src/lib.rs', + ], + ), + override_options: ['rust_std=2021', 'build.rust_std=2021'], + rust_abi: 'rust', + dependencies: [ + bilge_rs, + bilge_impl_rs, + bits_rs, + common_rs, + glib_sys_rs, + util_rs, + migration_rs, + bql_rs, + qom_rs, + chardev_rs, + system_rs, + hwcore_rs, + trace_rs + ], +) + +rust_devices_ss.add(when: 'CONFIG_X_PCF8574_RUST', if_true: [declare_dependency( + link_whole: [_libpcf8574_rs], + variables: {'crate': 'pcf8574'}, +)]) diff --git a/rust/hw/gpio/pcf8574/src/lib.rs b/rust/hw/gpio/pcf8574/src/lib.rs new file mode 100644 index 0000000000..4bec081876 --- /dev/null +++ b/rust/hw/gpio/pcf8574/src/lib.rs @@ -0,0 +1,178 @@ +// Copyright 2025 HUST OpenAtom Open Source Club. +// Author(s): Chen Miao <[email protected]> +// SPDX-License-Identifier: GPL-2.0-or-later + +use std::slice::from_ref; + +use bql::BqlRefCell; +use common::bitops::IntegerExt; +use hwcore::{ + DeviceClass, DeviceImpl, DeviceMethods, DeviceState, I2CResult, I2CSlave, I2CSlaveImpl, + InterruptSource, ResetType, ResettablePhasesImpl, +}; +use migration::{ + self, impl_vmstate_struct, vmstate_fields, vmstate_of, VMStateDescription, + VMStateDescriptionBuilder, +}; +use qom::{qom_isa, IsA, Object, ObjectImpl, ObjectType, ParentField}; + +pub const TYPE_PCF8574: &::std::ffi::CStr = c"pcf8574"; +const PORTS_COUNT: usize = 8; + +#[repr(C)] +#[derive(Clone, Copy, Debug, Default)] +pub struct PCF8574Inner { + pub lastrq: u8, + pub input: u8, + pub output: u8, +} + +impl PCF8574Inner { + pub fn line_state(&self) -> u8 { + self.input & self.output + } + + pub fn set_output(&mut self, data: u8) -> (u8, u8) { + let prev = self.line_state(); + self.output = data; + let actual = self.line_state(); + (prev, actual) + } + + pub fn set_input(&mut self, start: u32, value: u8) -> bool { + self.input = self.input.deposit(start, 1, value); + self.has_state_changed() + } + + pub fn receive(&mut self) -> (bool, u8) { + let state_changed = self.has_state_changed(); + if state_changed { + self.lastrq = self.line_state(); + } + (state_changed, self.lastrq) + } + + pub fn has_state_changed(&self) -> bool { + self.line_state() != self.lastrq + } +} + +#[repr(C)] +#[derive(qom::Object, hwcore::Device)] +pub struct PCF8574State { + pub parent_obj: ParentField<I2CSlave>, + pub inner: BqlRefCell<PCF8574Inner>, + pub handler: [InterruptSource; PORTS_COUNT], + pub intrq: InterruptSource, +} + +// static_assert!(size_of::<PCF8574State>() <= size_of::<crate::bindings::PCF8574State>()); + +qom_isa!(PCF8574State: I2CSlave, DeviceState, Object); + +#[allow(dead_code)] +trait PCF8574Impl: I2CSlaveImpl + IsA<PCF8574State> {} + +unsafe impl ObjectType for PCF8574State { + type Class = DeviceClass; + const TYPE_NAME: &'static std::ffi::CStr = crate::TYPE_PCF8574; +} + +impl PCF8574Impl for PCF8574State {} + +impl ObjectImpl for PCF8574State { + type ParentType = I2CSlave; + const CLASS_INIT: fn(&mut Self::Class) = Self::Class::class_init::<Self>; +} + +impl DeviceImpl for PCF8574State { + const VMSTATE: Option<migration::VMStateDescription<Self>> = Some(VMSTATE_PCF8574); + const REALIZE: Option<fn(&Self) -> util::Result<()>> = Some(Self::realize); +} + +impl ResettablePhasesImpl for PCF8574State { + const HOLD: Option<fn(&Self, ResetType)> = Some(Self::reset_hold); +} + +impl I2CSlaveImpl for PCF8574State { + const SEND: Option<fn(&Self, data: u8) -> I2CResult> = Some(Self::send); + const RECV: Option<fn(&Self) -> u8> = Some(Self::recv); +} + +impl PCF8574State { + fn send(&self, data: u8) -> I2CResult { + let (prev, actual) = self.inner.borrow_mut().set_output(data); + + let mut diff = actual ^ prev; + while diff != 0 { + let line = diff.trailing_zeros() as u8; + if let Some(handler) = self.handler.get(line as usize) { + handler.set((actual >> line) & 1 == 1); + } + diff &= !(1 << line); + } + + self.intrq.set(actual == self.inner.borrow().lastrq); + + I2CResult::ACK + } + + fn recv(&self) -> u8 { + let (has_changed, actual) = self.inner.borrow_mut().receive(); + if has_changed { + self.intrq.raise(); + } + + actual + } + + fn realize(&self) -> util::Result<()> { + self.init_gpio_in(self.handler_size(), PCF8574State::gpio_set); + self.init_gpio_out(from_ref(&self.handler[0])); + self.init_gpio_out_named(from_ref(&self.intrq), "nINT", 1); + Ok(()) + } + + fn gpio_set(&self, line: u32, level: u32) { + assert!(line < self.handler_size()); + + if self + .inner + .borrow_mut() + .set_input(line, u8::from(level != 0)) + { + self.intrq.raise(); + } + } + + fn handler_size(&self) -> u32 { + self.handler.len() as u32 + } + + fn reset_hold(&self, _type: ResetType) {} +} + +impl_vmstate_struct!( + PCF8574Inner, + VMStateDescriptionBuilder::<PCF8574Inner>::new() + .name(c"pcf8574/inner") + .version_id(0) + .minimum_version_id(0) + .fields(vmstate_fields! { + vmstate_of!(PCF8574Inner, lastrq), + vmstate_of!(PCF8574Inner, input), + vmstate_of!(PCF8574Inner, output), + }) + .build() +); + +pub const VMSTATE_PCF8574: VMStateDescription<PCF8574State> = + VMStateDescriptionBuilder::<PCF8574State>::new() + .name(c"pcf8574") + .version_id(0) + .minimum_version_id(0) + .fields(vmstate_fields! { + vmstate_of!(PCF8574State, parent_obj), + vmstate_of!(PCF8574State, inner), + }) + .build(); diff --git a/rust/hw/meson.build b/rust/hw/meson.build index 9749d4adfc..d6b273170e 100644 --- a/rust/hw/meson.build +++ b/rust/hw/meson.build @@ -1,2 +1,3 @@ subdir('char') +subdir('gpio') subdir('timer') -- 2.43.0
