Linux那些事儿之我是EHCI(5) 2008年的这一场雪

来源：互联网发布：imovie在mac上怎么导出编辑：程序博客网时间：2024/05/22 19:42

2008年的这一场雪，比以往时候来的要大一些。以前是买不到票，这次有票也走不了了。

此时此刻，多少兄弟姐妹被困在路上，饥寒交迫，多少城市停电停水，物价飞涨。我真是忍不住破口大骂，好一个和谐盛世！虽说是天灾，但岂无人祸？直接原因是那该死的冻雨。但我认为罪魁乃是三峡工程，以及所谓南水北调。

祝愿那些困在铁路，公路上的人们早日回家团圆，大家过个好年。

还是先看看股市，有消息称，"导致大盘暴跌的原因是因为大面积的降雪, 导致大量的股民滞留车站,机场.无法进入股市抄底, 待在家中人员又因大面积的停电而无法上网操作, 导致了今天的大资金无法介入, 请大家不要恐慌。据不完全统计有60%的基金操盘手被困在机场吃方便面。"

闲话少讲，先补上一张图，

我们接着usb_hcd_pci_probe()往下走，89 - 108行，是为EHCI申请io内存，92行request_mem_region()申请，98行做一次mapping，在EHCI(1)中曾经提到过，EHCI的接口有3种，第一种是PCI配置寄存器，第二种是io内存，第三种就是普通的内存。这里先把EHCI的io内存登记，再做一次ioremap映射成虚拟地址。

接下来126 pci_set_master() 见UHCI 4 http://blog.csdn.net/fudan_abc/archive/2007/10/04/1811451.aspx

128行进入了 usb_add_hcd()

   1548 /**
   1549 * usb_add_hcd - finish generic HCD structure initialization and register
   1550 * @hcd: the usb_hcd structure to initialize
   1551 * @irqnum: Interrupt line to allocate
   1552 * @irqflags: Interrupt type flags
   1553 *

1554 * Finish the remaining parts of generic HCD initialization: allocate the

1555 * buffers of consistent memory, register the bus, request the IRQ line,

1556 * and call the driver's reset() and start() routines.

1557 */

1558 int usb_add_hcd(struct usb_hcd *hcd,

1559 unsigned int irqnum, unsigned long irqflags)

1560 {

1561 int retval;

1562 struct usb_device *rhdev;

1563

1564 dev_info(hcd->self.controller, "%s/n", hcd->product_desc);

1565

1566 set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);

1567

1568 /* HC is in reset state, but accessible. Now do the one-time init,

1569 * bottom up so that hcds can customize the root hubs before khubd

1570 * starts talking to them. (Note, bus id is assigned early too.)

1571 */

1572 if ((retval = hcd_buffer_create(hcd)) != 0) {

1573 dev_dbg(hcd->self.controller, "pool alloc failed/n");

1574 return retval;

1575 }

1576

1577 if ((retval = usb_register_bus(&hcd->self)) < 0)

1578 goto err_register_bus;

1579

1580 if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {

1581 dev_err(hcd->self.controller, "unable to allocate root hub/n");

1582 retval = -ENOMEM;

1583 goto err_allocate_root_hub;

1584 }

1585 rhdev->speed = (hcd->driver->flags & HCD_USB2) ?USB_SPEED_HIGH :

1586 USB_SPEED_FULL;

1587 hcd->self.root_hub = rhdev;

1588

1589 /* wakeup flag init defaults to "everything works" for root hubs,

1590 * but drivers can override it in reset() if needed, along with

1591 * recording the overall controller's system wakeup capability.

1592 */

1593 device_init_wakeup(&rhdev->dev, 1);

1594

1595 /* "reset" is misnamed; its role is now one-time init. the controller

1596 * should already have been reset (and boot firmware kicked off etc).

1597 */

1598 if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {

1599 dev_err(hcd->self.controller, "can't setup/n");

1600 goto err_hcd_driver_setup;

1601 }

1602

1603 /* NOTE: root hub and controller capabilities may not be the same */

1604 if (device_can_wakeup(hcd->self.controller)

1605 && device_can_wakeup(&hcd->self.root_hub->dev))

1606 dev_dbg(hcd->self.controller, "supports USB remote wakeup/n");

1607

1608 /* enable irqs just before we start the controller */

1609 if (hcd->driver->irq) {

1610 snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",

1611 hcd->driver->description, hcd->self.busnum);

1612 if ((retval = request_irq(irqnum, &usb_hcd_irq, irqflags,

1613 hcd->irq_descr, hcd)) != 0) {

1614 dev_err(hcd->self.controller,

1615 "request interrupt %d failed/n", irqnum);

1616 goto err_request_irq;

1617 }

1618 hcd->irq = irqnum;

1619 dev_info(hcd->self.controller, "irq %d, %s 0x%08llx/n", irqnum,

1620 (hcd->driver->flags & HCD_MEMORY) ?

1621 "io mem" : "io base",

1622 (unsigned long long)hcd->rsrc_start);

1623 } else {

1624 hcd->irq = -1;

1625 if (hcd->rsrc_start)

1626 dev_info(hcd->self.controller, "%s 0x%08llx/n", 1627 (hcd->driver->flags & HCD_MEMORY) ?

1628 "io mem" : "io base",

1629 (unsigned long long)hcd->rsrc_start);

1630 }

1631

1632 if ((retval = hcd->driver->start(hcd)) < 0) {

1633 dev_err(hcd->self.controller, "startup error %d/n", retval);

1634 goto err_hcd_driver_start;

1635 }

1636

1637 /* starting here, usbcore will pay attention to this root hub */

1638 rhdev->bus_mA = min(500u, hcd->power_budget);

1639 if ((retval = register_root_hub(hcd)) != 0)

1640 goto err_register_root_hub;

1641

1642 if (hcd->uses_new_polling && hcd->poll_rh)

1643 usb_hcd_poll_rh_status(hcd);

1644 return retval;

1645

1646 err_register_root_hub:

1647 hcd->driver->stop(hcd);

1648 err_hcd_driver_start:

1649 if (hcd->irq >= 0)

1650 free_irq(irqnum, hcd);

1651 err_request_irq:

1652 err_hcd_driver_setup:

1653 hcd->self.root_hub = NULL;

1654 usb_put_dev(rhdev);

1655 err_allocate_root_hub:

1656 usb_deregister_bus(&hcd->self);

1657 err_register_bus:

1658 hcd_buffer_destroy(hcd);

1659 return retval;

1660 }

1572行hcd_buffer_create()见 UHCI 5 http://blog.csdn.net/fudan_abc/archive/2007/10/10/1818462.aspx。简单总结一下，创建, 摧毁buffur: hcd_buffer_create() / hcd_buffer_destroy()，创建之后，从池子里索取或者把索取的释放回去，usb_buffer_alloc()/usb_buffer_free()。

1577行usb_register_bus见UHCI 6 http://blog.csdn.net/fudan_abc/archive/2007/10/13/1823287.aspx。简单来说，把自己连入到全局变量usb_bus_list中，并调用class_device_create往sysfs新加入一个class。

1580行usb_alloc_dev()，UHCI 7 http://blog.csdn.net/fudan_abc/archive/2007/10/16/1827449.aspx。

1598行之前，都和UHCI没有什么分别，hcd->driver->reset指向的是，ehci_pci_hc_driver.ehci_pci_setup()

转至http://blog.csdn.net/fudan_abc/article/details/2070570