1
// SPDX-License-Identifier: GPL-2.0
2

3
//! Rust I2C client registration sample.
4
//!
5
//! An I2C client in Rust cannot exist on its own. To register a new I2C client,
6
//! it must be bound to a parent device. In this sample driver, a platform device
7
//! is used as the parent.
8
//!
9

10
//! ACPI match table test
11
//!
12
//! This demonstrates how to test an ACPI-based Rust I2C client registration driver
13
//! using QEMU with a custom SSDT.
14
//!
15
//! Steps:
16
//!
17
//! 1. **Create an SSDT source file** (`ssdt.dsl`) with the following content:
18
//!
19
//!     ```asl
20
//!     DefinitionBlock ("", "SSDT", 2, "TEST", "VIRTACPI", 0x00000001)
21
//!     {
22
//!         Scope (\_SB)
23
//!         {
24
//!             Device (T432)
25
//!             {
26
//!                 Name (_HID, "LNUXBEEF")  // ACPI hardware ID to match
27
//!                 Name (_UID, 1)
28
//!                 Name (_STA, 0x0F)        // Device present, enabled
29
//!                 Name (_CRS, ResourceTemplate ()
30
//!                 {
31
//!                     Memory32Fixed (ReadWrite, 0xFED00000, 0x1000)
32
//!                 })
33
//!             }
34
//!         }
35
//!     }
36
//!     ```
37
//!
38
//! 2. **Compile the table**:
39
//!
40
//!     ```sh
41
//!     iasl -tc ssdt.dsl
42
//!     ```
43
//!
44
//!     This generates `ssdt.aml`
45
//!
46
//! 3. **Run QEMU** with the compiled AML file:
47
//!
48
//!     ```sh
49
//!     qemu-system-x86_64 -m 512M \
50
//!         -enable-kvm \
51
//!         -kernel path/to/bzImage \
52
//!         -append "root=/dev/sda console=ttyS0" \
53
//!         -hda rootfs.img \
54
//!         -serial stdio \
55
//!         -acpitable file=ssdt.aml
56
//!     ```
57
//!
58
//!     Requirements:
59
//!     - The `rust_driver_platform` must be present either:
60
//!         - built directly into the kernel (`bzImage`), or
61
//!         - available as a `.ko` file and loadable from `rootfs.img`
62
//!
63
//! 4. **Verify it worked** by checking `dmesg`:
64
//!
65
//!     ```
66
//!     rust_driver_platform LNUXBEEF:00: Probed with info: '0'.
67
//!     ```
68
//!
69

70
use kernel::{
71
    acpi,
72
    device,
73
    devres::Devres,
74
    i2c,
75
    of,
76
    platform,
77
    prelude::*,
78
    sync::aref::ARef, //
79
};
80

81
#[pin_data]
82
struct SampleDriver {
83
    parent_dev: ARef<platform::Device>,
84
    #[pin]
85
    _reg: Devres<i2c::Registration>,
86
}
87

88
kernel::of_device_table!(
89
    OF_TABLE,
90
    MODULE_OF_TABLE,
91
    <SampleDriver as platform::Driver>::IdInfo,
92
    [(of::DeviceId::new(c"test,rust-device"), ())]
93
);
94

95
kernel::acpi_device_table!(
96
    ACPI_TABLE,
97
    MODULE_ACPI_TABLE,
98
    <SampleDriver as platform::Driver>::IdInfo,
99
    [(acpi::DeviceId::new(c"LNUXBEEF"), ())]
100
);
101

102
const SAMPLE_I2C_CLIENT_ADDR: u16 = 0x30;
103
const SAMPLE_I2C_ADAPTER_INDEX: i32 = 0;
104
const BOARD_INFO: i2c::I2cBoardInfo =
105
    i2c::I2cBoardInfo::new(c"rust_driver_i2c", SAMPLE_I2C_CLIENT_ADDR);
106

107
impl platform::Driver for SampleDriver {
108
    type IdInfo = ();
109
    const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
110
    const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
111

112
    fn probe(
113
        pdev: &platform::Device<device::Core>,
114
        _info: Option<&Self::IdInfo>,
115
    ) -> impl PinInit<Self, Error> {
116
        dev_info!(
117
            pdev.as_ref(),
118
            "Probe Rust I2C Client registration sample.\n"
119
        );
120

121
        kernel::try_pin_init!( Self {
122
            parent_dev: pdev.into(),
123

124
            _reg <- {
125
                let adapter = i2c::I2cAdapter::get(SAMPLE_I2C_ADAPTER_INDEX)?;
126

127
                i2c::Registration::new(&adapter, &BOARD_INFO, pdev.as_ref())
128
            }
129
        })
130
    }
131

132
    fn unbind(pdev: &platform::Device<device::Core>, _this: Pin<&Self>) {
133
        dev_info!(
134
            pdev.as_ref(),
135
            "Unbind Rust I2C Client registration sample.\n"
136
        );
137
    }
138
}
139

140
kernel::module_platform_driver! {
141
    type: SampleDriver,
142
    name: "rust_device_i2c",
143
    authors: ["Danilo Krummrich", "Igor Korotin"],
144
    description: "Rust I2C client registration",
145
    license: "GPL v2",
146
}
147

148