xref: /linux/drivers/net/phy/ax88796b_rust.rs (revision b4db9f840283caca0d904436f187ef56a9126eaa)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2023 FUJITA Tomonori <fujita.tomonori@gmail.com>
3 
4 //! Rust Asix PHYs driver
5 //!
6 //! C version of this driver: [`drivers/net/phy/ax88796b.c`](./ax88796b.c)
7 use kernel::{
8     c_str,
9     net::phy::{self, DeviceId, Driver},
10     prelude::*,
11     uapi,
12 };
13 
14 kernel::module_phy_driver! {
15     drivers: [PhyAX88772A, PhyAX88772C, PhyAX88796B],
16     device_table: [
17         DeviceId::new_with_driver::<PhyAX88772A>(),
18         DeviceId::new_with_driver::<PhyAX88772C>(),
19         DeviceId::new_with_driver::<PhyAX88796B>()
20     ],
21     name: "rust_asix_phy",
22     author: "FUJITA Tomonori <fujita.tomonori@gmail.com>",
23     description: "Rust Asix PHYs driver",
24     license: "GPL",
25 }
26 
27 const MII_BMCR: u16 = uapi::MII_BMCR as u16;
28 const BMCR_SPEED100: u16 = uapi::BMCR_SPEED100 as u16;
29 const BMCR_FULLDPLX: u16 = uapi::BMCR_FULLDPLX as u16;
30 
31 // Performs a software PHY reset using the standard
32 // BMCR_RESET bit and poll for the reset bit to be cleared.
33 // Toggle BMCR_RESET bit off to accommodate broken AX8796B PHY implementation
34 // such as used on the Individual Computers' X-Surf 100 Zorro card.
35 fn asix_soft_reset(dev: &mut phy::Device) -> Result {
36     dev.write(uapi::MII_BMCR as u16, 0)?;
37     dev.genphy_soft_reset()
38 }
39 
40 struct PhyAX88772A;
41 
42 #[vtable]
43 impl Driver for PhyAX88772A {
44     const FLAGS: u32 = phy::flags::IS_INTERNAL;
45     const NAME: &'static CStr = c_str!("Asix Electronics AX88772A");
46     const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_exact_mask(0x003b1861);
47 
48     // AX88772A is not working properly with some old switches (NETGEAR EN 108TP):
49     // after autoneg is done and the link status is reported as active, the MII_LPA
50     // register is 0. This issue is not reproducible on AX88772C.
51     fn read_status(dev: &mut phy::Device) -> Result<u16> {
52         dev.genphy_update_link()?;
53         if !dev.is_link_up() {
54             return Ok(0);
55         }
56         // If MII_LPA is 0, phy_resolve_aneg_linkmode() will fail to resolve
57         // linkmode so use MII_BMCR as default values.
58         let ret = dev.read(MII_BMCR)?;
59 
60         if ret & BMCR_SPEED100 != 0 {
61             dev.set_speed(uapi::SPEED_100);
62         } else {
63             dev.set_speed(uapi::SPEED_10);
64         }
65 
66         let duplex = if ret & BMCR_FULLDPLX != 0 {
67             phy::DuplexMode::Full
68         } else {
69             phy::DuplexMode::Half
70         };
71         dev.set_duplex(duplex);
72 
73         dev.genphy_read_lpa()?;
74 
75         if dev.is_autoneg_enabled() && dev.is_autoneg_completed() {
76             dev.resolve_aneg_linkmode();
77         }
78 
79         Ok(0)
80     }
81 
82     fn suspend(dev: &mut phy::Device) -> Result {
83         dev.genphy_suspend()
84     }
85 
86     fn resume(dev: &mut phy::Device) -> Result {
87         dev.genphy_resume()
88     }
89 
90     fn soft_reset(dev: &mut phy::Device) -> Result {
91         asix_soft_reset(dev)
92     }
93 
94     fn link_change_notify(dev: &mut phy::Device) {
95         // Reset PHY, otherwise MII_LPA will provide outdated information.
96         // This issue is reproducible only with some link partner PHYs.
97         if dev.state() == phy::DeviceState::NoLink {
98             let _ = dev.init_hw();
99             let _ = dev.start_aneg();
100         }
101     }
102 }
103 
104 struct PhyAX88772C;
105 
106 #[vtable]
107 impl Driver for PhyAX88772C {
108     const FLAGS: u32 = phy::flags::IS_INTERNAL;
109     const NAME: &'static CStr = c_str!("Asix Electronics AX88772C");
110     const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_exact_mask(0x003b1881);
111 
112     fn suspend(dev: &mut phy::Device) -> Result {
113         dev.genphy_suspend()
114     }
115 
116     fn resume(dev: &mut phy::Device) -> Result {
117         dev.genphy_resume()
118     }
119 
120     fn soft_reset(dev: &mut phy::Device) -> Result {
121         asix_soft_reset(dev)
122     }
123 }
124 
125 struct PhyAX88796B;
126 
127 #[vtable]
128 impl Driver for PhyAX88796B {
129     const NAME: &'static CStr = c_str!("Asix Electronics AX88796B");
130     const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_model_mask(0x003b1841);
131 
132     fn soft_reset(dev: &mut phy::Device) -> Result {
133         asix_soft_reset(dev)
134     }
135 }
136