| Paul Mundt | 85b59f5 | 2010-02-01 13:01:42 +0900 | [diff] [blame^] | 1 | #include <linux/pci.h> |
| 2 | #include <linux/kernel.h> |
| 3 | |
| 4 | static int __init |
| 5 | early_read_config_word(struct pci_channel *hose, |
| 6 | int top_bus, int bus, int devfn, int offset, u16 *value) |
| 7 | { |
| 8 | struct pci_dev fake_dev; |
| 9 | struct pci_bus fake_bus; |
| 10 | |
| 11 | fake_dev.bus = &fake_bus; |
| 12 | fake_dev.sysdata = hose; |
| 13 | fake_dev.devfn = devfn; |
| 14 | fake_bus.number = bus; |
| 15 | fake_bus.sysdata = hose; |
| 16 | fake_bus.ops = hose->pci_ops; |
| 17 | |
| 18 | if (bus != top_bus) |
| 19 | /* Fake a parent bus structure. */ |
| 20 | fake_bus.parent = &fake_bus; |
| 21 | else |
| 22 | fake_bus.parent = NULL; |
| 23 | |
| 24 | return pci_read_config_word(&fake_dev, offset, value); |
| 25 | } |
| 26 | |
| 27 | int __init pci_is_66mhz_capable(struct pci_channel *hose, |
| 28 | int top_bus, int current_bus) |
| 29 | { |
| 30 | u32 pci_devfn; |
| 31 | unsigned short vid; |
| 32 | int cap66 = -1; |
| 33 | u16 stat; |
| 34 | |
| 35 | printk(KERN_INFO "PCI: Checking 66MHz capabilities...\n"); |
| 36 | |
| 37 | for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) { |
| 38 | if (PCI_FUNC(pci_devfn)) |
| 39 | continue; |
| 40 | if (early_read_config_word(hose, top_bus, current_bus, |
| 41 | pci_devfn, PCI_VENDOR_ID, &vid) != |
| 42 | PCIBIOS_SUCCESSFUL) |
| 43 | continue; |
| 44 | if (vid == 0xffff) |
| 45 | continue; |
| 46 | |
| 47 | /* check 66MHz capability */ |
| 48 | if (cap66 < 0) |
| 49 | cap66 = 1; |
| 50 | if (cap66) { |
| 51 | early_read_config_word(hose, top_bus, current_bus, |
| 52 | pci_devfn, PCI_STATUS, &stat); |
| 53 | if (!(stat & PCI_STATUS_66MHZ)) { |
| 54 | printk(KERN_DEBUG |
| 55 | "PCI: %02x:%02x not 66MHz capable.\n", |
| 56 | current_bus, pci_devfn); |
| 57 | cap66 = 0; |
| 58 | break; |
| 59 | } |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | return cap66 > 0; |
| 64 | } |