xref: /linux/samples/rust/rust_driver_auxiliary.rs (revision c7f6d5380f6ef5c328b63807c4e9b73eaef9aeda)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 //! Rust auxiliary driver sample (based on a PCI driver for QEMU's `pci-testdev`).
4 //!
5 //! To make this driver probe, QEMU must be run with `-device pci-testdev`.
6 
7 use kernel::{
8     auxiliary, c_str, device::Core, driver, error::Error, pci, prelude::*, InPlaceModule,
9 };
10 
11 use pin_init::PinInit;
12 
13 const MODULE_NAME: &CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
14 const AUXILIARY_NAME: &CStr = c_str!("auxiliary");
15 
16 struct AuxiliaryDriver;
17 
18 kernel::auxiliary_device_table!(
19     AUX_TABLE,
20     MODULE_AUX_TABLE,
21     <AuxiliaryDriver as auxiliary::Driver>::IdInfo,
22     [(auxiliary::DeviceId::new(MODULE_NAME, AUXILIARY_NAME), ())]
23 );
24 
25 impl auxiliary::Driver for AuxiliaryDriver {
26     type IdInfo = ();
27 
28     const ID_TABLE: auxiliary::IdTable<Self::IdInfo> = &AUX_TABLE;
29 
30     fn probe(adev: &auxiliary::Device<Core>, _info: &Self::IdInfo) -> impl PinInit<Self, Error> {
31         dev_info!(
32             adev.as_ref(),
33             "Probing auxiliary driver for auxiliary device with id={}\n",
34             adev.id()
35         );
36 
37         ParentDriver::connect(adev)?;
38 
39         Ok(Self)
40     }
41 }
42 
43 struct ParentDriver {
44     _reg: [auxiliary::Registration; 2],
45 }
46 
47 kernel::pci_device_table!(
48     PCI_TABLE,
49     MODULE_PCI_TABLE,
50     <ParentDriver as pci::Driver>::IdInfo,
51     [(pci::DeviceId::from_id(pci::Vendor::REDHAT, 0x5), ())]
52 );
53 
54 impl pci::Driver for ParentDriver {
55     type IdInfo = ();
56 
57     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
58 
59     fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> impl PinInit<Self, Error> {
60         Ok(Self {
61             _reg: [
62                 auxiliary::Registration::new(pdev.as_ref(), AUXILIARY_NAME, 0, MODULE_NAME)?,
63                 auxiliary::Registration::new(pdev.as_ref(), AUXILIARY_NAME, 1, MODULE_NAME)?,
64             ],
65         })
66     }
67 }
68 
69 impl ParentDriver {
70     fn connect(adev: &auxiliary::Device) -> Result<()> {
71         let parent = adev.parent().ok_or(EINVAL)?;
72         let pdev: &pci::Device = parent.try_into()?;
73 
74         let vendor = pdev.vendor_id();
75         dev_info!(
76             adev.as_ref(),
77             "Connect auxiliary {} with parent: VendorID={}, DeviceID={:#x}\n",
78             adev.id(),
79             vendor,
80             pdev.device_id()
81         );
82 
83         Ok(())
84     }
85 }
86 
87 #[pin_data]
88 struct SampleModule {
89     #[pin]
90     _pci_driver: driver::Registration<pci::Adapter<ParentDriver>>,
91     #[pin]
92     _aux_driver: driver::Registration<auxiliary::Adapter<AuxiliaryDriver>>,
93 }
94 
95 impl InPlaceModule for SampleModule {
96     fn init(module: &'static kernel::ThisModule) -> impl PinInit<Self, Error> {
97         try_pin_init!(Self {
98             _pci_driver <- driver::Registration::new(MODULE_NAME, module),
99             _aux_driver <- driver::Registration::new(MODULE_NAME, module),
100         })
101     }
102 }
103 
104 module! {
105     type: SampleModule,
106     name: "rust_driver_auxiliary",
107     authors: ["Danilo Krummrich"],
108     description: "Rust auxiliary driver",
109     license: "GPL v2",
110 }
111