xref: /linux/samples/rust/rust_driver_auxiliary.rs (revision 23b0f90ba871f096474e1c27c3d14f455189d2d9)
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,
9     device::{
10         Bound,
11         Core, //
12     },
13     devres::Devres,
14     driver,
15     pci,
16     prelude::*,
17     InPlaceModule, //
18 };
19 
20 use core::any::TypeId;
21 
22 const MODULE_NAME: &CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
23 const AUXILIARY_NAME: &CStr = c"auxiliary";
24 
25 struct AuxiliaryDriver;
26 
27 kernel::auxiliary_device_table!(
28     AUX_TABLE,
29     MODULE_AUX_TABLE,
30     <AuxiliaryDriver as auxiliary::Driver>::IdInfo,
31     [(auxiliary::DeviceId::new(MODULE_NAME, AUXILIARY_NAME), ())]
32 );
33 
34 impl auxiliary::Driver for AuxiliaryDriver {
35     type IdInfo = ();
36 
37     const ID_TABLE: auxiliary::IdTable<Self::IdInfo> = &AUX_TABLE;
38 
39     fn probe(adev: &auxiliary::Device<Core>, _info: &Self::IdInfo) -> impl PinInit<Self, Error> {
40         dev_info!(
41             adev,
42             "Probing auxiliary driver for auxiliary device with id={}\n",
43             adev.id()
44         );
45 
46         ParentDriver::connect(adev)?;
47 
48         Ok(Self)
49     }
50 }
51 
52 #[pin_data]
53 struct ParentDriver {
54     private: TypeId,
55     #[pin]
56     _reg0: Devres<auxiliary::Registration>,
57     #[pin]
58     _reg1: Devres<auxiliary::Registration>,
59 }
60 
61 kernel::pci_device_table!(
62     PCI_TABLE,
63     MODULE_PCI_TABLE,
64     <ParentDriver as pci::Driver>::IdInfo,
65     [(pci::DeviceId::from_id(pci::Vendor::REDHAT, 0x5), ())]
66 );
67 
68 impl pci::Driver for ParentDriver {
69     type IdInfo = ();
70 
71     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
72 
73     fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> impl PinInit<Self, Error> {
74         try_pin_init!(Self {
75             private: TypeId::of::<Self>(),
76             _reg0 <- auxiliary::Registration::new(pdev.as_ref(), AUXILIARY_NAME, 0, MODULE_NAME),
77             _reg1 <- auxiliary::Registration::new(pdev.as_ref(), AUXILIARY_NAME, 1, MODULE_NAME),
78         })
79     }
80 }
81 
82 impl ParentDriver {
83     fn connect(adev: &auxiliary::Device<Bound>) -> Result {
84         let dev = adev.parent();
85         let pdev: &pci::Device<Bound> = dev.try_into()?;
86         let drvdata = dev.drvdata::<Self>()?;
87 
88         dev_info!(
89             dev,
90             "Connect auxiliary {} with parent: VendorID={}, DeviceID={:#x}\n",
91             adev.id(),
92             pdev.vendor_id(),
93             pdev.device_id()
94         );
95 
96         dev_info!(
97             dev,
98             "We have access to the private data of {:?}.\n",
99             drvdata.private
100         );
101 
102         Ok(())
103     }
104 }
105 
106 #[pin_data]
107 struct SampleModule {
108     #[pin]
109     _pci_driver: driver::Registration<pci::Adapter<ParentDriver>>,
110     #[pin]
111     _aux_driver: driver::Registration<auxiliary::Adapter<AuxiliaryDriver>>,
112 }
113 
114 impl InPlaceModule for SampleModule {
115     fn init(module: &'static kernel::ThisModule) -> impl PinInit<Self, Error> {
116         try_pin_init!(Self {
117             _pci_driver <- driver::Registration::new(MODULE_NAME, module),
118             _aux_driver <- driver::Registration::new(MODULE_NAME, module),
119         })
120     }
121 }
122 
123 module! {
124     type: SampleModule,
125     name: "rust_driver_auxiliary",
126     authors: ["Danilo Krummrich"],
127     description: "Rust auxiliary driver",
128     license: "GPL v2",
129 }
130