ohci.c

超小usb协议栈

		printk("Bad port # passed to ohci_reset_port\n");
		port = MAX_ROOT_PORTS-1;
	}

	writel(PORT_PRS, &ohci->regs->roothub.portstatus[port]);  /* Reset */

	/*
	 * Get the time required for a root hub port to reset and wait
	 * it out (adding 1ms for good measure).
	 */
	ms = (readl(&ohci->regs->roothub.a) >> 24) * 2 + 1;
	wait_ms(ms);

	/* check port status to see that the reset completed */
	status = readl(&ohci->regs->roothub.portstatus[port]);
	if (status & PORT_PRS) {
		/* reset failed, try harder? */
		printk("usb-ohci: port %d reset failed, retrying\n", port);
		writel(PORT_PRS, &ohci->regs->roothub.portstatus[port]);
		wait_ms(50);
	}

	/* TODO we might need to re-enable the port here or is that
	 * done elsewhere? */

} /* ohci_reset_port */


/*
 * This gets called if the connect status on the root hub changes.
 */
static void ohci_connect_change(struct ohci * ohci, int port)
{
	struct usb_device *usb_dev;
	struct ohci_device *dev;
	/* memory I/O address of the port status register */
	void *portaddr = &ohci->regs->roothub.portstatus[port];
	int portstatus;	

	/*
	 * Because of the status change we have to forget
	 * everything we think we know about the device
	 * on this root hub port.  It may have changed.
	 */
	usb_disconnect(ohci->root_hub->usb->children + port);

	portstatus = readl(portaddr);

	/* disable the port if nothing is connected */
	if (!(portstatus & PORT_CCS)) {
		writel(PORT_CCS, portaddr);
		return;
	}

	/*
	 * Allocate a device for the new thingy that's been attached
	 */
	usb_dev = ohci_usb_allocate(ohci->root_hub->usb);
	dev = usb_dev->hcpriv;

	dev->ohci = ohci;

	usb_connect(dev->usb);

	/* link it into the bus's device tree */
	ohci->root_hub->usb->children[port] = usb_dev;

	wait_ms(200); /* wait for powerup; XXX is this needed? */
	ohci_reset_port(ohci, port);

	/* Get information on speed by using LSD */
	usb_dev->slow = readl(portaddr) & PORT_LSDA ? 1 : 0;

	/*
	 * Do generic USB device tree processing on the new device.
	 */
	usb_new_device(usb_dev);
} /* ohci_connect_change() */


/*
 * This gets called when the root hub configuration
 * has changed.  Just go through each port, seeing if
 * there is something interesting happening.
 */
static void ohci_check_configuration(struct ohci *ohci)
{
	int num = 0;
	int maxport = readl(&ohci->regs->roothub) & 0xff;

	do {
		if (readl(ohci->regs->roothub.portstatus[num]) & PORT_CSC)
			ohci_connect_change(ohci, num);
	} while (++num < maxport);
} /* ohci_check_configuration() */


/*
 * Get annoyed at the controller for bothering us.
 */
static void ohci_interrupt(int irq, void *__ohci, struct pt_regs *r)
{
	struct ohci *ohci = __ohci;
	struct ohci_regs *regs = ohci->regs;
	struct ohci_hcca *hcca = ohci->root_hub->hcca;
	__u32 donehead = hcca->donehead;

	/*
	 * Check the interrupt status register if needed
	 */
	if (!donehead || (donehead & 1)) {
		__u32 intrstatus = readl(&regs->intrstatus);

		/*
		 * XXX eek! printk's in an interrupt handler.  shoot me!
		 */
		if (intrstatus & OHCI_INTR_SO) {
			printk(KERN_DEBUG "usb-ohci: scheduling overrun\n");
		}
		if (intrstatus & OHCI_INTR_RD) {
			printk(KERN_DEBUG "usb-ohci: resume detected\n");
		}
		if (intrstatus & OHCI_INTR_UE) {
			printk(KERN_DEBUG "usb-ohci: unrecoverable error\n");
		}
		if (intrstatus & OHCI_INTR_OC) {
			printk(KERN_DEBUG "usb-ohci: ownership change?\n");
		}

		if (intrstatus & OHCI_INTR_RHSC) {
			/* TODO Process events on the root hub */
		}
	}

	/*
	 * Process the done list
	 */
	if (donehead &= ~0x1) {
		/*
		 * TODO See which TD's completed..
		 */
	}

	/* Re-enable done queue interrupts and reset the donehead */
	hcca->donehead = 0;
	writel(OHCI_INTR_WDH, &regs->intrenable);
	
} /* ohci_interrupt() */


/*
 * Allocate the resources required for running an OHCI controller.
 * Host controller interrupts must not be running while calling this
 * function or the penguins will get angry.
 *
 * The mem_base parameter must be the usable -virtual- address of the
 * host controller's memory mapped I/O registers.
 */
static struct ohci *alloc_ohci(void* mem_base)
{
	int i;
	struct ohci *ohci;
	struct usb_bus *bus;
	struct ohci_device *dev;
	struct usb_device *usb;

	ohci = kmalloc(sizeof(*ohci), GFP_KERNEL);
	if (!ohci)
		return NULL;

	memset(ohci, 0, sizeof(*ohci));

	ohci->irq = -1;
	ohci->regs = mem_base;
	INIT_LIST_HEAD(&ohci->interrupt_list);

	bus = kmalloc(sizeof(*bus), GFP_KERNEL);
	if (!bus)
		return NULL;

	memset(bus, 0, sizeof(*bus));

	ohci->bus = bus;
	bus->hcpriv = ohci;
	bus->op = &ohci_device_operations;

	/*
	 * Here we allocate our own root hub and TDs as well as the
	 * OHCI host controller communications area.  The HCCA is just
	 * a nice pool of memory with pointers to endpoint descriptors
	 * for the different interrupts.
	 */
	usb = ohci_usb_allocate(NULL);
	if (!usb)
		return NULL;

	dev = ohci->root_hub = usb_to_ohci(usb);

	usb->bus = bus;

	/* Initialize the root hub */
	memset(dev, 0, sizeof(*dev));
	dev->ohci = ohci;    /* link back to the controller */

	/*
	 * Allocate the Host Controller Communications Area
	 */
	dev->hcca = (struct ohci_hcca *) kmalloc(sizeof(*dev->hcca), GFP_KERNEL);

	/* Tell the controller where the HCCA is */
	writel(virt_to_bus(dev->hcca), &ohci->regs->hcca);

	/* Get the number of ports on the root hub */
	usb->maxchild = readl(&ohci->regs->roothub.a) & 0xff;
	if (usb->maxchild > MAX_ROOT_PORTS) {
		printk("usb-ohci: Limited to %d ports\n", MAX_ROOT_PORTS);
		usb->maxchild = MAX_ROOT_PORTS;
	}
	if (usb->maxchild < 1) {
		printk("usb-ohci: Less than one root hub port? Impossible!\n");
		usb->maxchild = 1;
	}
	printk("usb-ohci: %d root hub ports found\n", usb->maxchild);

	printk("alloc_ohci() controller\n");
	show_ohci_status(ohci);
	printk("alloc_ohci() root_hub device\n");
	show_ohci_device(dev);

	/*
	 * Initialize the ED polling "tree" (for simplicity's sake in
	 * this driver many nodes in the tree will be identical)
	 */
	dev->ed[ED_INT_32].next_ed = virt_to_bus(&dev->ed[ED_INT_16]);
	dev->ed[ED_INT_16].next_ed = virt_to_bus(&dev->ed[ED_INT_8]);
	dev->ed[ED_INT_8].next_ed = virt_to_bus(&dev->ed[ED_INT_4]);
	dev->ed[ED_INT_4].next_ed = virt_to_bus(&dev->ed[ED_INT_2]);
	dev->ed[ED_INT_2].next_ed = virt_to_bus(&dev->ed[ED_INT_1]);

	/*
	 * Initialize the polling table to call interrupts at the
	 * intended intervals.
	 */
	for (i = 0; i < NUM_INTS; i++) {
		if (i == 0)
			dev->hcca->int_table[i] =
				virt_to_bus(&dev->ed[ED_INT_32]);
		else if (i & 1)
			dev->hcca->int_table[i] =
				virt_to_bus(&dev->ed[ED_INT_16]);
		else if (i & 2)
			dev->hcca->int_table[i] =
				virt_to_bus(&dev->ed[ED_INT_8]);
		else if (i & 4)
			dev->hcca->int_table[i] =
				virt_to_bus(&dev->ed[ED_INT_4]);
		else if (i & 8)
			dev->hcca->int_table[i] =
				virt_to_bus(&dev->ed[ED_INT_2]);
		else if (i & 16)
			dev->hcca->int_table[i] =
				virt_to_bus(&dev->ed[ED_INT_1]);
	}

	/*
	 * Tell the controller where the control and bulk lists are
	 */
	writel(virt_to_bus(&dev->ed[ED_CONTROL]), &ohci->regs->ed_controlhead);
	writel(virt_to_bus(&dev->ed[ED_BULK]), &ohci->regs->ed_bulkhead);

	return ohci;
} /* alloc_ohci() */


/*
 * De-allocate all resoueces..
 */
static void release_ohci(struct ohci *ohci)
{
	if (ohci->irq >= 0) {
		free_irq(ohci->irq, ohci);
		ohci->irq = -1;
	}

	if (ohci->root_hub) {
		/* ensure that HC is stopped before releasing the HCCA */
		writel(OHCI_USB_SUSPEND, &ohci->regs->control);
		free_pages((unsigned int) ohci->root_hub->hcca, 1);
		free_pages((unsigned int) ohci->root_hub, 1);
		ohci->root_hub->hcca = NULL;
		ohci->root_hub = NULL;
	}

	/* unmap the IO address space */
	iounmap(ohci->regs);

	/* If the ohci itself were dynamic we'd free it here */

} /* release_ohci() */

/*
 * USB OHCI control thread
 */
static int ohci_control_thread(void * __ohci)
{
	struct ohci *ohci = (struct ohci *)__ohci;
	
	/*
	 * I'm unfamiliar with the SMP kernel locking.. where should
	 * this be released?  -greg
	 */
	lock_kernel();

	/*
	 * This thread doesn't need any user-level access,
	 * so get rid of all of our resources..
	 */
	printk("ohci_control_thread at %p\n", &ohci_control_thread);
	exit_mm(current);
	exit_files(current);
	exit_fs(current);

	strcpy(current->comm, "ohci-control");

	/*
	 * Damn the torpedoes, full speed ahead
	 */
	start_hc(ohci);
	do {
		interruptible_sleep_on(&ohci_configure);
#ifdef CONFIG_APM
		if (apm_resume) {
			apm_resume = 0;
			start_hc(ohci);
			continue;
		}
#endif
		ohci_check_configuration(ohci);
	} while (!signal_pending(current));

	reset_hc(ohci);

	release_ohci(ohci);
	MOD_DEC_USE_COUNT;
	return 0;
} /* ohci_control_thread() */


#ifdef CONFIG_APM
static int handle_apm_event(apm_event_t event)
{
	static int down = 0;

	switch (event) {
	case APM_SYS_SUSPEND:
	case APM_USER_SUSPEND:
		if (down) {
			printk(KERN_DEBUG "usb-ohci: received extra suspend event\n");
			break;
		}
		down = 1;
		break;
	case APM_NORMAL_RESUME:
	case APM_CRITICAL_RESUME:
		if (!down) {
			printk(KERN_DEBUG "usb-ohci: received bogus resume event\n");
			break;
		}
		down = 0;
		if (waitqueue_active(&ohci_configure)) {
			apm_resume = 1;
			wake_up(&ohci_configure);
		}
		break;
	}
	return 0;
}
#endif

/* ... */

/*
 * Increment the module usage count, start the control thread and
 * return success if the controller is good.
 */
static int found_ohci(int irq, void* mem_base)
{
	int retval;
	struct ohci *ohci;

	/* Allocate the running OHCI structures */
	ohci = alloc_ohci(mem_base);
	if (!ohci)
		return -ENOMEM;

	printk("usb-ohci: alloc_ohci() = %p\n", ohci);

	reset_hc(ohci);

	retval = -EBUSY;
	if (request_irq(irq, ohci_interrupt, SA_SHIRQ, "usb-ohci", ohci) == 0) {
		int pid;

		MOD_INC_USE_COUNT;
		ohci->irq = irq;

		/* fork off the handler */
		pid = kernel_thread(ohci_control_thread, ohci,
				CLONE_FS | CLONE_FILES | CLONE_SIGHAND);
		if (pid >= 0)
			return 0;

		MOD_DEC_USE_COUNT;
		retval = pid;
	}
	release_ohci(ohci);
	return retval;
} /* found_ohci() */


/*
 * If this controller is for real, map the IO memory and proceed
 */
static int init_ohci(struct pci_dev *dev)
{
	unsigned int mem_base = dev->base_address[0];
	
	printk("usb-ohci: mem_base is %p\n", (void*)mem_base);

	/* If its OHCI, its memory */
	if (mem_base & PCI_BASE_ADDRESS_SPACE_IO)
		return -ENODEV;

	/* Get the memory address and map it for IO */
	mem_base &= PCI_BASE_ADDRESS_MEM_MASK;
	/* 
	 * FIXME ioremap_nocache isn't implemented on all CPUs (such
	 * as the Alpha) [?]  What should I use instead...
	 *
	 * The iounmap() is done on in release_ohci.
	 */
	mem_base = (unsigned int) ioremap_nocache(mem_base, 4096);

	if (!mem_base) {
		printk("Error mapping OHCI memory\n");
		return -EFAULT;
	}

	return found_ohci(dev->irq, (void *) mem_base);
} /* init_ohci() */


/* TODO this should be named following Linux convention and go in pci.h */
#define PCI_CLASS_SERIAL_USB_OHCI ((PCI_CLASS_SERIAL_USB << 8) | 0x0010)

/*
 * Search the PCI bus for an OHCI USB controller and set it up
 *
 * If anyone wants multiple controllers this will need to be
 * updated..  Right now, it just picks the first one it finds.
 */
int init_module(void)
{
	int retval;
	struct pci_dev *dev = NULL;
	/*u8 type;*/

	if (sizeof(struct ohci_device) > 4096) {
		printk("usb-ohci: struct ohci_device to large\n");
		return -ENODEV;
	}

	retval = -ENODEV;
	for (;;) {
		/* Find an OHCI USB controller */
		dev = pci_find_class(PCI_CLASS_SERIAL_USB_OHCI, dev);
		if (!dev)
			break;

		/* Verify that its OpenHCI by checking for MMIO */
		/* pci_read_config_byte(dev, PCI_CLASS_PROG, &type);
		if (!type)
			continue; */

		/* Ok, set it up */
		retval = init_ohci(dev);
		if (retval < 0)
			continue;

		/* TODO check module params here to determine what to load */

/*		usb_mouse_init(); */
/*		usb_kbd_init();
		hub_init();	*/
#ifdef CONFIG_APM
		apm_register_callback(&handle_apm_event);
#endif

		return 0; /* no error */
	}
	return retval;
} /* init_module() */


/*
 *  Clean up when unloading the module
 */
void cleanup_module(void)
{
#ifdef CONFIG_APM
	apm_unregister_callback(&handle_apm_event);
#endif
}

/* vim:sw=8
 */