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1. PCI DEVICE DRIVER
1

2. 什麼是PCI (Peripheral Component Interconnect)
它是一種電腦的硬體bus
可以讓多個週邊在上面運行，主要是給電
腦擴充週邊用的
它有分host端和client端，一個host可以接多
個client (最多可達32個)
可以經由PCI bridge串接更多的PCI client
它的速度有33M 和66M兩種
I/O為32bits，而記憶體可32或64b its
2

3. 3
PCI System

4. 4
PCI Pin

5. 5
PCI 設定表

6. 6
Base address設定方式

7. 7
PCI啓動流程
PCI Host 控制器
初始化，並將
可分配的資源
設定好
PCI Host開始掃
描看看Bus上有
多少個PCI Client
元件
針對每一個PCI
Client元件給予分
配可用資源
尋找PCI Client是否有登
記PCI probe callback，
若有就給予呼叫(依據
vendor & device ID)

8. 8
PCI Host Driver
宣告一個struct
hw_pci的資料
結構
呼叫
pci_common_i
nit()
系統呼叫註冊的
preinit callback
function初始該PCI
Host元件
系統呼叫setup
callback function
設定PCI Host可
分配的資源
系統呼叫scan
callback function
並準備好struct
pci_ops並開始掃
描PCI client元件
啓動PCI
client元
件

9. struct hw_pci 範例mach-ixp4xx/ixdp425-pci.c
struct hw_pci ixdp425_pci __initdata = {
.nr_controllers = 1,
.preinit = ixdp425_pci_preinit,
.swizzle = pci_std_swizzle,
.setup = ixp4xx_setup,
.scan = ixp4xx_scan_bus,
.map_irq = ixdp425_map_irq,
};
9
int __init ixdp425_pci_init(void)
{
if (machine_is_ixdp425() || machine_is_ixcdp1100() ||
machine_is_ixdp465() || machine_is_kixrp435())
pci_common_init(&ixdp425_pci);
return 0;
}
subsys_initcall(ixdp425_pci_init);

10. 保留系統所有PCI的資源
在setup callback function中作保留的動作
1) arch/arm/mach-ixp4xx/common-pci.c
int ixp4xx_setup(int nr, struct pci_sys_data *sys) {
struct resource *res;
res[0].name = "PCI I/O Space";
res[0].start = 0x00000000;
res[0].end = 0x0000ffff;
res[0].flags = IORESOURCE_IO;
res[1].name = "PCI Memory Space";
res[1].start = PCIBIOS_MIN_MEM;
res[1].end = 0x4bffffff;
res[1].flags = IORESOURCE_MEM;
request_resource(&ioport_resource, &res[0]);
request_resource(&iomem_resource, &res[1]);
sys->resource[0] = &res[0];
sys->resource[1] = &res[1];
sys->resource[2] = NULL;
return 1;
}
10

11. struct pci_ops 範例
static struct pci_ops ftpci_ops = {
.read = ftpci_read_config,
.write = ftpci_write_config,
};
其操作是給PCI Client Driver在讀PCI table時
所使用的基本API (HAL)
系統呼叫scan_bus call back function 中會呼
叫pci_scan_bus(sys->busnr, &ixp4xx_ops, sys);
時給予註冊(arch/arm/mach-ixp4xx/common-pci.
c) 11

12. 12
PCI Host分配資源流程
PCI Host
Scan Device
Read device
configuration
table to get
requests
Assign
resources to
device on
configuration
table
比對Vendor ID &
Device ID 確認是
否有任何PCI
Device Driver 登
錄
呼叫己登
錄的probe
callback
function

13. static struct pci_driver rtl8139_pci_driver = {
.name = DRV_NAME,
.id_table = rtl8139_pci_tbl,
.probe = rtl8139_init_one,
.remove = __devexit_p(rtl8139_remove_one),
#ifdef CONFIG_PM
.suspend = rtl8139_suspend,
.resume = rtl8139_resume,
#endif /* CONFIG_PM */
};
static int __init rtl8139_init_module (void)
{
/* when we're a module, we always print a version message,
* even if no 8139 board is found.
*/
#ifdef MODULE
pr_info(RTL8139_DRIVER_NAME "n");
#endif
return pci_register_driver(&rtl8139_pci_driver);
}
13
PCI Client Driver

14. struct pci_device_id範例
static struct pci_device_id rtl8139_pci_tbl[] = {
{0x10ec, 0x8139, PCI_ANY_ID, PCI_ANY_ID, 0, 0, RTL8139 },
{0x10ec, 0x8138, PCI_ANY_ID, PCI_ANY_ID, 0, 0, RTL8139 },
{0x1113, 0x1211, PCI_ANY_ID, PCI_ANY_ID, 0, 0, RTL8139 },
{0x1500, 0x1360, PCI_ANY_ID, PCI_ANY_ID, 0, 0, RTL8139 },
{0x4033, 0x1360, PCI_ANY_ID, PCI_ANY_ID, 0, 0, RTL8139 },
{0x1186, 0x1300, PCI_ANY_ID, PCI_ANY_ID, 0, 0, RTL8139 },
{0x1186, 0x1340, PCI_ANY_ID, PCI_ANY_ID, 0, 0, RTL8139 },
{0}
};
14

15. PCI Client如何取得被分配的資源
pci_enable_device (pdev);
pio_start = pci_resource_start (pdev, 0);
pio_end = pci_resource_end (pdev, 0);
pio_flags = pci_resource_flags (pdev, 0);
pio_len = pci_resource_len (pdev, 0);
mmio_start = pci_resource_start (pdev, 1);
mmio_end = pci_resource_end (pdev, 1);
mmio_flags = pci_resource_flags (pdev, 1);
mmio_len = pci_resource_len (pdev, 1);
15

16. PCI Bus有分I/O及memory access，而ARM只
有memory access，所以在assign I/O
resource 時要小心
有的PCI controller需要改寫outb/inb &
readb/writeb HAL API (arch/io.h)
16
注意事項
CPU
PCI Host
Controller
PCI Client
Device
Local
Bus
PCI
Bus

17. 17
PCI Host Controller I
CPU
PCI Host
Controller
PCI
Device
I/O Access
Memory Access
Local
Bus
Local
Bus
PCI
Bus
PCI
Bus

18. 18
PCI Host Controller II
CPU
PCI Host
Controller
PCI
Device
I/O Access
Memory Access
I/O
CMD
Mem
CMD
PCI
Bus
PCI
Bus

19. PCI Host Controller II porting
在mach-xxx/include/mach目錄之下建主一個
檔案io.h
若需redirect PCI access則不要宣告以下
1) #define _ _mem_pci(a) (a)
2) #define _ _io(v) _ _typesafe_io(v)
Examples
1) mach-ixp4xx/include/mach/io.h
19