hcd.c

linux core 函数例程

/*
 * (C) Copyright Linus Torvalds 1999
 * (C) Copyright Johannes Erdfelt 1999-2001
 * (C) Copyright Andreas Gal 1999
 * (C) Copyright Gregory P. Smith 1999
 * (C) Copyright Deti Fliegl 1999
 * (C) Copyright Randy Dunlap 2000
 * (C) Copyright David Brownell 2000-2002
 * 
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/config.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/uts.h>			/* for UTS_SYSNAME */


#ifdef CONFIG_USB_DEBUG
	#define DEBUG
#else
	#undef DEBUG
#endif

#include <linux/usb.h>
#include "hcd.h"

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/unaligned.h>
#include <asm/byteorder.h>


// #define USB_BANDWIDTH_MESSAGES

/*-------------------------------------------------------------------------*/

/*
 * USB Host Controller Driver framework
 *
 * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
 * HCD-specific behaviors/bugs.
 *
 * This does error checks, tracks devices and urbs, and delegates to a
 * "hc_driver" only for code (and data) that really needs to know about
 * hardware differences.  That includes root hub registers, i/o queues,
 * and so on ... but as little else as possible.
 *
 * Shared code includes most of the "root hub" code (these are emulated,
 * though each HC's hardware works differently) and PCI glue, plus request
 * tracking overhead.  The HCD code should only block on spinlocks or on
 * hardware handshaking; blocking on software events (such as other kernel
 * threads releasing resources, or completing actions) is all generic.
 *
 * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
 * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
 * only by the hub driver ... and that neither should be seen or used by
 * usb client device drivers.
 *
 * Contributors of ideas or unattributed patches include: David Brownell,
 * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
 *
 * HISTORY:
 * 2002-02-21	Pull in most of the usb_bus support from usb.c; some
 *		associated cleanup.  "usb_hcd" still != "usb_bus".
 * 2001-12-12	Initial patch version for Linux 2.5.1 kernel.
 */

/*-------------------------------------------------------------------------*/

/* host controllers we manage */
LIST_HEAD (usb_bus_list);

/* used when allocating bus numbers */
#define USB_MAXBUS		64
struct usb_busmap {
	unsigned long busmap [USB_MAXBUS / (8*sizeof (unsigned long))];
};
static struct usb_busmap busmap;

/* used when updating list of hcds */
DECLARE_MUTEX (usb_bus_list_lock);	/* exported only for usbfs */

/* used when updating hcd data */
static spinlock_t hcd_data_lock = SPIN_LOCK_UNLOCKED;

static struct usb_operations hcd_operations;

/*-------------------------------------------------------------------------*/

/*
 * Sharable chunks of root hub code.
 */

/*-------------------------------------------------------------------------*/

#define KERNEL_REL	((LINUX_VERSION_CODE >> 16) & 0x0ff)
#define KERNEL_VER	((LINUX_VERSION_CODE >> 8) & 0x0ff)

/* usb 2.0 root hub device descriptor */
static const u8 usb2_rh_dev_descriptor [18] = {
	0x12,       /*  __u8  bLength; */
	0x01,       /*  __u8  bDescriptorType; Device */
	0x00, 0x02, /*  __u16 bcdUSB; v2.0 */

	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
	0x00,	    /*  __u8  bDeviceSubClass; */
	0x01,       /*  __u8  bDeviceProtocol; [ usb 2.0 single TT ]*/
	0x08,       /*  __u8  bMaxPacketSize0; 8 Bytes */

	0x00, 0x00, /*  __u16 idVendor; */
 	0x00, 0x00, /*  __u16 idProduct; */
	KERNEL_VER, KERNEL_REL, /*  __u16 bcdDevice */

	0x03,       /*  __u8  iManufacturer; */
	0x02,       /*  __u8  iProduct; */
	0x01,       /*  __u8  iSerialNumber; */
	0x01        /*  __u8  bNumConfigurations; */
};

/* no usb 2.0 root hub "device qualifier" descriptor: one speed only */

/* usb 1.1 root hub device descriptor */
static const u8 usb11_rh_dev_descriptor [18] = {
	0x12,       /*  __u8  bLength; */
	0x01,       /*  __u8  bDescriptorType; Device */
	0x10, 0x01, /*  __u16 bcdUSB; v1.1 */

	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
	0x00,	    /*  __u8  bDeviceSubClass; */
	0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
	0x08,       /*  __u8  bMaxPacketSize0; 8 Bytes */

	0x00, 0x00, /*  __u16 idVendor; */
 	0x00, 0x00, /*  __u16 idProduct; */
	KERNEL_VER, KERNEL_REL, /*  __u16 bcdDevice */

	0x03,       /*  __u8  iManufacturer; */
	0x02,       /*  __u8  iProduct; */
	0x01,       /*  __u8  iSerialNumber; */
	0x01        /*  __u8  bNumConfigurations; */
};


/*-------------------------------------------------------------------------*/

/* Configuration descriptors for our root hubs */

static const u8 fs_rh_config_descriptor [] = {

	/* one configuration */
	0x09,       /*  __u8  bLength; */
	0x02,       /*  __u8  bDescriptorType; Configuration */
	0x19, 0x00, /*  __u16 wTotalLength; */
	0x01,       /*  __u8  bNumInterfaces; (1) */
	0x01,       /*  __u8  bConfigurationValue; */
	0x00,       /*  __u8  iConfiguration; */
	0x40,       /*  __u8  bmAttributes; 
				 Bit 7: Bus-powered,
				     6: Self-powered,
				     5 Remote-wakwup,
				     4..0: resvd */
	0x00,       /*  __u8  MaxPower; */
      
	/* USB 1.1:
	 * USB 2.0, single TT organization (mandatory):
	 *	one interface, protocol 0
	 *
	 * USB 2.0, multiple TT organization (optional):
	 *	two interfaces, protocols 1 (like single TT)
	 *	and 2 (multiple TT mode) ... config is
	 *	sometimes settable
	 *	NOT IMPLEMENTED
	 */

	/* one interface */
	0x09,       /*  __u8  if_bLength; */
	0x04,       /*  __u8  if_bDescriptorType; Interface */
	0x00,       /*  __u8  if_bInterfaceNumber; */
	0x00,       /*  __u8  if_bAlternateSetting; */
	0x01,       /*  __u8  if_bNumEndpoints; */
	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
	0x00,       /*  __u8  if_bInterfaceSubClass; */
	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
	0x00,       /*  __u8  if_iInterface; */
     
	/* one endpoint (status change endpoint) */
	0x07,       /*  __u8  ep_bLength; */
	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
 	0x02, 0x00, /*  __u16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
	0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
};

static const u8 hs_rh_config_descriptor [] = {

	/* one configuration */
	0x09,       /*  __u8  bLength; */
	0x02,       /*  __u8  bDescriptorType; Configuration */
	0x19, 0x00, /*  __u16 wTotalLength; */
	0x01,       /*  __u8  bNumInterfaces; (1) */
	0x01,       /*  __u8  bConfigurationValue; */
	0x00,       /*  __u8  iConfiguration; */
	0x40,       /*  __u8  bmAttributes; 
				 Bit 7: Bus-powered,
				     6: Self-powered,
				     5 Remote-wakwup,
				     4..0: resvd */
	0x00,       /*  __u8  MaxPower; */
      
	/* USB 1.1:
	 * USB 2.0, single TT organization (mandatory):
	 *	one interface, protocol 0
	 *
	 * USB 2.0, multiple TT organization (optional):
	 *	two interfaces, protocols 1 (like single TT)
	 *	and 2 (multiple TT mode) ... config is
	 *	sometimes settable
	 *	NOT IMPLEMENTED
	 */

	/* one interface */
	0x09,       /*  __u8  if_bLength; */
	0x04,       /*  __u8  if_bDescriptorType; Interface */
	0x00,       /*  __u8  if_bInterfaceNumber; */
	0x00,       /*  __u8  if_bAlternateSetting; */
	0x01,       /*  __u8  if_bNumEndpoints; */
	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
	0x00,       /*  __u8  if_bInterfaceSubClass; */
	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
	0x00,       /*  __u8  if_iInterface; */
     
	/* one endpoint (status change endpoint) */
	0x07,       /*  __u8  ep_bLength; */
	0x05,       /*  __u8  ep_bDescriptorType; Endpoint */
	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
 	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
 	0x02, 0x00, /*  __u16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
	0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
};

/*-------------------------------------------------------------------------*/

/*
 * helper routine for returning string descriptors in UTF-16LE
 * input can actually be ISO-8859-1; ASCII is its 7-bit subset
 */
static int ascii2utf (char *s, u8 *utf, int utfmax)
{
	int retval;

	for (retval = 0; *s && utfmax > 1; utfmax -= 2, retval += 2) {
		*utf++ = *s++;
		*utf++ = 0;
	}
	return retval;
}

/*
 * rh_string - provides manufacturer, product and serial strings for root hub
 * @id: the string ID number (1: serial number, 2: product, 3: vendor)
 * @pci_desc: PCI device descriptor for the relevant HC
 * @type: string describing our driver 
 * @data: return packet in UTF-16 LE
 * @len: length of the return packet
 *
 * Produces either a manufacturer, product or serial number string for the
 * virtual root hub device.
 */
static int rh_string (
	int		id,
	struct usb_hcd	*hcd,
	u8		*data,
	int		len
) {
	char buf [100];

	// language ids
	if (id == 0) {
		*data++ = 4; *data++ = 3;	/* 4 bytes string data */
		*data++ = 0; *data++ = 0;	/* some language id */
		return 4;

	// serial number
	} else if (id == 1) {
		strcpy (buf, hcd->self.bus_name);

	// product description
	} else if (id == 2) {
                strcpy (buf, hcd->product_desc);

 	// id 3 == vendor description
	} else if (id == 3) {
                sprintf (buf, "%s %s %s", UTS_SYSNAME, UTS_RELEASE,
			hcd->description);

	// unsupported IDs --> "protocol stall"
	} else
	    return 0;

	data [0] = 2 + ascii2utf (buf, data + 2, len - 2);
	data [1] = 3;	/* type == string */
	return data [0];
}


/* Root hub control transfers execute synchronously */
static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
{
	struct usb_ctrlrequest *cmd = (struct usb_ctrlrequest *) urb->setup_packet;
 	u16		typeReq, wValue, wIndex, wLength;
	const u8	*bufp = 0;
	u8		*ubuf = urb->transfer_buffer;
	int		len = 0;

	typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
	wValue   = le16_to_cpu (cmd->wValue);
	wIndex   = le16_to_cpu (cmd->wIndex);
	wLength  = le16_to_cpu (cmd->wLength);

	if (wLength > urb->transfer_buffer_length)
		goto error;

	/* set up for success */
	urb->status = 0;
	urb->actual_length = wLength;
	switch (typeReq) {

	/* DEVICE REQUESTS */

	case DeviceRequest | USB_REQ_GET_STATUS:
		// DEVICE_REMOTE_WAKEUP
		ubuf [0] = 1; // selfpowered
		ubuf [1] = 0;
			/* FALLTHROUGH */
	case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
	case DeviceOutRequest | USB_REQ_SET_FEATURE:
		dbg ("no device features yet yet");
		break;
	case DeviceRequest | USB_REQ_GET_CONFIGURATION:
		ubuf [0] = 1;
			/* FALLTHROUGH */
	case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
		break;
	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
		switch (wValue & 0xff00) {
		case USB_DT_DEVICE << 8:
			if (hcd->driver->flags & HCD_USB2)
				bufp = usb2_rh_dev_descriptor;
			else if (hcd->driver->flags & HCD_USB11)
				bufp = usb11_rh_dev_descriptor;
			else
				goto error;
			len = 18;
			break;
		case USB_DT_CONFIG << 8:
			if (hcd->driver->flags & HCD_USB2) {
				bufp = hs_rh_config_descriptor;
				len = sizeof hs_rh_config_descriptor;
			} else {
				bufp = fs_rh_config_descriptor;
				len = sizeof fs_rh_config_descriptor;
			}
			break;
		case USB_DT_STRING << 8:
			urb->actual_length = rh_string (
				wValue & 0xff, hcd,
				ubuf, wLength);
			break;
		default:
			goto error;
		}
		break;
	case DeviceRequest | USB_REQ_GET_INTERFACE:
		ubuf [0] = 0;
			/* FALLTHROUGH */
	case DeviceOutRequest | USB_REQ_SET_INTERFACE:
		break;
	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
		// wValue == urb->dev->devaddr
		dbg ("%s root hub device address %d",
			hcd->self.bus_name, wValue);
		break;

	/* INTERFACE REQUESTS (no defined feature/status flags) */

	/* ENDPOINT REQUESTS */

	case EndpointRequest | USB_REQ_GET_STATUS:
		// ENDPOINT_HALT flag
		ubuf [0] = 0;
		ubuf [1] = 0;
			/* FALLTHROUGH */
	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
	case EndpointOutRequest | USB_REQ_SET_FEATURE:
		dbg ("no endpoint features yet");
		break;

	/* CLASS REQUESTS (and errors) */

	default:
		/* non-generic request */
		urb->status = hcd->driver->hub_control (hcd,
			typeReq, wValue, wIndex,
			ubuf, wLength);
		break;
error:
		/* "protocol stall" on error */
		urb->status = -EPIPE;
		dbg ("unsupported hub control message (maxchild %d)",
				urb->dev->maxchild);
	}
	if (urb->status) {
		urb->actual_length = 0;
		dbg ("CTRL: TypeReq=0x%x val=0x%x idx=0x%x len=%d ==> %d",
			typeReq, wValue, wIndex, wLength, urb->status);
	}
	if (bufp) {
		if (urb->transfer_buffer_length < len)
			len = urb->transfer_buffer_length;
		urb->actual_length = len;
		// always USB_DIR_IN, toward host
		memcpy (ubuf, bufp, len);
	}