xref: /linux/samples/rust/rust_driver_auxiliary.rs (revision 0074281bb6316108e0cff094bd4db78ab3eee236)
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, bindings, 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 
probe(adev: &auxiliary::Device<Core>, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>>30     fn probe(adev: &auxiliary::Device<Core>, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
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         let this = KBox::new(Self, GFP_KERNEL)?;
40 
41         Ok(this.into())
42     }
43 }
44 
45 struct ParentDriver {
46     _reg: [auxiliary::Registration; 2],
47 }
48 
49 kernel::pci_device_table!(
50     PCI_TABLE,
51     MODULE_PCI_TABLE,
52     <ParentDriver as pci::Driver>::IdInfo,
53     [(
54         pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_REDHAT, 0x5),
55         ()
56     )]
57 );
58 
59 impl pci::Driver for ParentDriver {
60     type IdInfo = ();
61 
62     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
63 
probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>>64     fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
65         let this = KBox::new(
66             Self {
67                 _reg: [
68                     auxiliary::Registration::new(pdev.as_ref(), AUXILIARY_NAME, 0, MODULE_NAME)?,
69                     auxiliary::Registration::new(pdev.as_ref(), AUXILIARY_NAME, 1, MODULE_NAME)?,
70                 ],
71             },
72             GFP_KERNEL,
73         )?;
74 
75         Ok(this.into())
76     }
77 }
78 
79 impl ParentDriver {
connect(adev: &auxiliary::Device) -> Result<()>80     fn connect(adev: &auxiliary::Device) -> Result<()> {
81         let parent = adev.parent().ok_or(EINVAL)?;
82         let pdev: &pci::Device = parent.try_into()?;
83 
84         dev_info!(
85             adev.as_ref(),
86             "Connect auxiliary {} with parent: VendorID={:#x}, DeviceID={:#x}\n",
87             adev.id(),
88             pdev.vendor_id(),
89             pdev.device_id()
90         );
91 
92         Ok(())
93     }
94 }
95 
96 #[pin_data]
97 struct SampleModule {
98     #[pin]
99     _pci_driver: driver::Registration<pci::Adapter<ParentDriver>>,
100     #[pin]
101     _aux_driver: driver::Registration<auxiliary::Adapter<AuxiliaryDriver>>,
102 }
103 
104 impl InPlaceModule for SampleModule {
init(module: &'static kernel::ThisModule) -> impl PinInit<Self, Error>105     fn init(module: &'static kernel::ThisModule) -> impl PinInit<Self, Error> {
106         try_pin_init!(Self {
107             _pci_driver <- driver::Registration::new(MODULE_NAME, module),
108             _aux_driver <- driver::Registration::new(MODULE_NAME, module),
109         })
110     }
111 }
112 
113 module! {
114     type: SampleModule,
115     name: "rust_driver_auxiliary",
116     authors: ["Danilo Krummrich"],
117     description: "Rust auxiliary driver",
118     license: "GPL v2",
119 }
120