blob: 6edb106fcbdb470ce3d7f24a95908ba3fbab83ed (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
@page page_device_pci_bridge PCI bridge function driver
# PCI bridge function driver (`host-bridge.c`)
**Not** the SoC host controller (@ref page_device_pci_host). This is the **`RT_PCI_DRIVER_EXPORT`** driver for **PCI bridge functions** (root ports, P2P bridges, certain virtual bridges).
Source: **`components/drivers/pci/host-bridge.c`**.
---
## Matched devices
```c
static const struct rt_pci_device_id host_bridge_pci_ids[] = {
{ RT_PCI_DEVICE_ID(PCI_VENDOR_ID_REDHAT, 0x0008) },
{ RT_PCI_DEVICE_CLASS(PCIS_BRIDGE_PCI_NORMAL, ~0) },
{ RT_PCI_DEVICE_CLASS(PCIS_BRIDGE_PCI_SUBTRACTIVE, ~0) },
{ RT_PCI_DEVICE_CLASS(((PCIS_SYSTEM_RCEC << 8) | 0x00), ~0) },
{ /* sentinel */ }
};
```
Vendor-specific bridge drivers should register **narrower** **`rt_pci_device_id`** entries **before** this generic match.
---
## Probe / remove
| Callback | Behavior |
| --- | --- |
| **`host_bridge_probe`** | **`rt_pci_set_master(pdev)`**; optional PM register |
| **`host_bridge_remove`** | **`rt_pci_clear_master`** |
| **`host_bridge_shutdown`** | PM unregister |
No BAR programming here — windows configured during enumeration (@ref page_device_pci_probe).
---
## Power management (`RT_USING_PM`)
**`host_bridge_pm_suspend` / `resume`**: **`rt_pci_enum_device`** on bus, **`rt_pci_enable_wake`** per function (@ref page_device_pci_pme).
| Sleep | PCI state |
| --- | --- |
| Idle | D3hot |
| Light / Deep | D1 |
| Standby | D2 |
| Shutdown | D3cold |
---
## Component map
| Layer | Location | Role |
| --- | --- | --- |
| Host RC | **`pci/host/`**, **`ecam.c`** | Enumeration |
| Bridge function | **`host-bridge.c`** | Bus master + PM on bridge devfn |
| OFW INTx | **`pci/ofw.c`** | **`interrupt-map`** |
---
## Pitfalls
| Issue | Mitigation |
| --- | --- |
| Expect BAR setup here | Done in core PCI |
| Generic class match | Override with specific driver if needed |
## See also
- @ref page_device_pci
- @ref page_device_pci_host
- @ref page_device_pci_pme
- @ref page_device_pci_ofw
|
