8.PCI驱动代码分析

01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
// 打印配置空间信息
void skel_get_configs(struct pci_dev* dev) {

    uint8_t revisin_id;
    uint16_t vendor_id, device_id;
    uint32_t class_id;

    pci_read_config_word(dev, PCI_VENDOR_ID, &vendor_id);
    printk("vendorID = %x", vendor_id);

    pci_read_config_word(dev, PCI_DEVICE_ID, &device_id);
    printk("deviceID = %x", device_id);

    pci_read_config_word(dev, PCI_REVISION_ID, &revisin_id);
    printk("deviceID = %x", revisin_id);

    pci_read_config_word(dev, PCI_CLASS_REVISION, &class_id);
    printk("classID = %x", class_id);
}

01
02
03
04
05
06
07
08
static irqreturn_t pci_mcard_interrupt(int irq, void* dev_id) {

    pci_card_t* pci_mcard = (pci_card_t*)dev_id;

    //打印中断号
    printk("irq = %d, pci_mcard_irq = %d\n", irq, pci_mcard->irq);
    return IRQ_HANDLED;
}

01
02
03
04
05
06
07
08
09
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
static int probe(struct pci_dev* dev, const struct pci_device_id* id) {

    int retval = 0;
    pci_card_t* pci_mcard;

    printk("probe func\n");

    // 设备使能
    if (pci_enable_device(dev)) {

        printk(KERN_ERR "IO Error.\n");
        return -EIO;
    }

    pci_mcard = kmalloc(sizeof(pci_card_t), GFP_KERNEL);
    if (!pci_mcard) {

        printk("In %s, kmalloc err!", __func__);
        return -ENOMEM;
    }

    // 设备中断号
    pci_mcard->irq = dev->irq;
    if (pci_mcard->irq < 0) {

        printk("IRQ is %d, it's invalid!\n", pci_mcard->irq);
        goto out_pci_mcard;
    }

    // 获取io内存相关信息
    pci_mcard->io = pci_resource_start(dev, 0);
    pci_mcard->range = pci_resource_end(dev, 0) - pci_mcard->io + 1;
    pci_mcard->flags = pci_resource_flags(dev, 0);
    printk("start %llx %lx %lx\n", pci_mcard->io, pci_mcard->range, pci_mcard->flags);
    printk("PCI base addr 0 is io%s.\n", (pci_mcard->flags & IORESOURCE_MEM) ? "mem" : "port");

    // 防止地址访问冲突 先申请
    retval = pci_request_regions(dev, "pci_module");
    if (retval) {

        printk("PCI request regions err!\n");
        goto out_pci_mcard;
    }

    // 在此映射
    pci_mcard->ioaddr = pci_ioremap_bar(dev, 0);
    if (!pci_mcard->ioaddr) {

        printk("ioremap err!\n");
        retval = -ENOMEM;
        goto out_regions;
    }

    retval = request_irq(pci_mcard->irq, pci_mcard_interrupt, IRQF_SHARED, "pci_module", pci_mcard);
    if (retval) {

        printk(KERN_ERR, "Can't get assigned IRQ %d.\n", pci_mcard->irq);
        goto out_iounmap;
    }

    pci_set_drvdata(dev, pci_mcard);
    skel_get_configs(dev);

    return 0;
out_iounmap:
    iounmap(pci_mcard->ioaddr);
out_regions:
    pci_release_regions(dev);
out_pci_mcard:
    kfree(pci_mcard);
    return retval;
}

01
02
03
04
05
06
07
08
09
10
static void remove(struct pci_dev* dev) {

    pci_card_t* pci_mcard = pci_get_drvdata(dev);
    free_irq(pci_mcard->irq, pci_mcard);
    iounmap(pci_mcard->ioaddr);
    pci_release_region(dev);
    kfree(pci_mcard);
    pci_disable_device(dev);
    printk(remove pci device ok.\n);
}