zd_usb.c

zd1211无线网卡驱动源代码

/* zd_usb.c
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <asm/unaligned.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/firmware.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/usb.h>
#include <net/ieee80211.h>

#include "zd_def.h"
#include "zd_netdev.h"
#include "zd_mac.h"
#include "zd_usb.h"
#include "zd_util.h"

static struct usb_device_id usb_ids[] = {
	/* ZD1211 */
	{ USB_DEVICE(0x0ace, 0x1211), .driver_info = DEVICE_ZD1211 },
	{ USB_DEVICE(0x07b8, 0x6001), .driver_info = DEVICE_ZD1211 },
	{ USB_DEVICE(0x126f, 0xa006), .driver_info = DEVICE_ZD1211 },
	{ USB_DEVICE(0x6891, 0xa727), .driver_info = DEVICE_ZD1211 },
	{ USB_DEVICE(0x0df6, 0x9071), .driver_info = DEVICE_ZD1211 },
	{ USB_DEVICE(0x157e, 0x300b), .driver_info = DEVICE_ZD1211 },
	/* ZD1211B */
	{ USB_DEVICE(0x0ace, 0x1215), .driver_info = DEVICE_ZD1211B },
	{ USB_DEVICE(0x157e, 0x300d), .driver_info = DEVICE_ZD1211B },
	{}
};

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
MODULE_AUTHOR("Ulrich Kunitz");
MODULE_AUTHOR("Daniel Drake");
MODULE_VERSION("1.0");
MODULE_DEVICE_TABLE(usb, usb_ids);

#define FW_ZD1211_PREFIX	"zd1211/zd1211_"
#define FW_ZD1211B_PREFIX	"zd1211/zd1211b_"

/* register address handling */

#ifdef DEBUG
static int check_addr(struct zd_usb *usb, zd_addr_t addr)
{
	u32 base = ZD_ADDR_BASE(addr);
	u32 offset = ZD_OFFSET(addr);

	if ((u32)addr & ADDR_ZERO_MASK)
		goto invalid_address;
	switch (base) {
	case USB_BASE:
		break;
	case CR_BASE:
		if (offset > CR_MAX_OFFSET) {
			dev_dbg(zd_usb_dev(usb),
				"CR offset %#010x larger than"
				" CR_MAX_OFFSET %#10x\n",
				offset, CR_MAX_OFFSET);
			goto invalid_address;
		}
		if (offset & 1) {
			dev_dbg(zd_usb_dev(usb),
				"CR offset %#010x is not a multiple of 2\n",
				offset);
			goto invalid_address;
		}
		break;
	case E2P_BASE:
		if (offset > E2P_MAX_OFFSET) {
			dev_dbg(zd_usb_dev(usb),
				"E2P offset %#010x larger than"
				" E2P_MAX_OFFSET %#010x\n",
				offset, E2P_MAX_OFFSET);
			goto invalid_address;
		}
		break;
	case FW_BASE:
		if (!usb->fw_base_offset) {
			dev_dbg(zd_usb_dev(usb),
			       "ERROR: fw base offset has not been set\n");
			return -EAGAIN;
		}
		if (offset > FW_MAX_OFFSET) {
			dev_dbg(zd_usb_dev(usb),
				"FW offset %#10x is larger than"
				" FW_MAX_OFFSET %#010x\n",
				offset, FW_MAX_OFFSET);
			goto invalid_address;
		}
		break;
	default:
		dev_dbg(zd_usb_dev(usb),
			"address has unsupported base %#010x\n", addr);
		goto invalid_address;
	}

	return 0;
invalid_address:
	dev_dbg(zd_usb_dev(usb),
		"ERROR: invalid address: %#010x\n", addr);
	return -EINVAL;
}
#endif /* DEBUG */

static u16 usb_addr(struct zd_usb *usb, zd_addr_t addr)
{
	u32 base;
	u16 offset;

	base = ZD_ADDR_BASE(addr);
	offset = ZD_OFFSET(addr);

	ZD_ASSERT(check_addr(usb, addr) == 0);

	switch (base) {
	case CR_BASE:
		offset += CR_BASE_OFFSET;
		break;
	case E2P_BASE:
		offset += E2P_BASE_OFFSET;
		break;
	case FW_BASE:
		offset += usb->fw_base_offset;
		break;
	}

	return offset;
}

/* USB device initialization */

static int request_fw_file(
	const struct firmware **fw, const char *name, struct device *device)
{
	int r;

	dev_dbg_f(device, "fw name %s\n", name);

	r = request_firmware(fw, name, device);
	if (r)
		dev_err(device,
		       "Could not load firmware file %s. Error number %d\n",
		       name, r);
	return r;
}

static inline u16 get_bcdDevice(const struct usb_device *udev)
{
	return le16_to_cpu(udev->descriptor.bcdDevice);
}

enum upload_code_flags {
	REBOOT = 1,
};

/* Ensures that MAX_TRANSFER_SIZE is even. */
#define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)

static int upload_code(struct usb_device *udev,
	const u8 *data, size_t size, u16 code_offset, int flags)
{
	u8 *p;
	int r;

	/* USB request blocks need "kmalloced" buffers.
	 */
	p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
	if (!p) {
		dev_err(&udev->dev, "out of memory\n");
		r = -ENOMEM;
		goto error;
	}

	size &= ~1;
	while (size > 0) {
		size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
			size : MAX_TRANSFER_SIZE;

		dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);

		memcpy(p, data, transfer_size);
		r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			USB_REQ_FIRMWARE_DOWNLOAD,
			USB_DIR_OUT | USB_TYPE_VENDOR,
			code_offset, 0, p, transfer_size, 1000 /* ms */);
		if (r < 0) {
			dev_err(&udev->dev,
			       "USB control request for firmware upload"
			       " failed. Error number %d\n", r);
			goto error;
		}
		transfer_size = r & ~1;

		size -= transfer_size;
		data += transfer_size;
		code_offset += transfer_size/sizeof(u16);
	}

	if (flags & REBOOT) {
		u8 ret;

		r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
			USB_REQ_FIRMWARE_CONFIRM,
			USB_DIR_IN | USB_TYPE_VENDOR,
			0, 0, &ret, sizeof(ret), 5000 /* ms */);
		if (r != sizeof(ret)) {
			dev_err(&udev->dev,
				"control request firmeware confirmation failed."
				" Return value %d\n", r);
			if (r >= 0)
				r = -ENODEV;
			goto error;
		}
		if (ret & 0x80) {
			dev_err(&udev->dev,
				"Internal error while downloading."
				" Firmware confirm return value %#04x\n",
				(unsigned int)ret);
			r = -ENODEV;
			goto error;
		}
		dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
			(unsigned int)ret);
	}

	r = 0;
error:
	kfree(p);
	return r;
}

static u16 get_word(const void *data, u16 offset)
{
	const __le16 *p = data;
	return le16_to_cpu(p[offset]);
}

static char *get_fw_name(char *buffer, size_t size, u8 device_type,
	               const char* postfix)
{
	scnprintf(buffer, size, "%s%s",
		device_type == DEVICE_ZD1211B ?
			FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
		postfix);
	return buffer;
}

static int upload_firmware(struct usb_device *udev, u8 device_type)
{
	int r;
	u16 fw_bcdDevice;
	u16 bcdDevice;
	const struct firmware *ub_fw = NULL;
	const struct firmware *uph_fw = NULL;
	char fw_name[128];

	bcdDevice = get_bcdDevice(udev);

	r = request_fw_file(&ub_fw,
		get_fw_name(fw_name, sizeof(fw_name), device_type,  "ub"),
		&udev->dev);
	if (r)
		goto error;

	fw_bcdDevice = get_word(ub_fw->data, EEPROM_REGS_OFFSET);

	/* FIXME: do we have any reason to perform the kludge that the vendor
	 * driver does when there is a version mismatch? (their driver uploads
	 * different firmwares and stuff)
	 */
	if (fw_bcdDevice != bcdDevice) {
		dev_info(&udev->dev,
			"firmware device id %#06x and actual device id "
			"%#06x differ, continuing anyway\n",
			fw_bcdDevice, bcdDevice);
	} else {
		dev_dbg_f(&udev->dev,
			"firmware device id %#06x is equal to the "
			"actual device id\n", fw_bcdDevice);
	}


	r = request_fw_file(&uph_fw,
		get_fw_name(fw_name, sizeof(fw_name), device_type, "uphr"),
		&udev->dev);
	if (r)
		goto error;

	r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START_OFFSET,
		        REBOOT);
	if (r) {
		dev_err(&udev->dev,
			"Could not upload firmware code uph. Error number %d\n",
			r);
	}

	/* FALL-THROUGH */
error:
	release_firmware(ub_fw);
	release_firmware(uph_fw);
	return r;
}

static void disable_read_regs_int(struct zd_usb *usb)
{
	struct zd_usb_interrupt *intr = &usb->intr;

	spin_lock(&intr->lock);
	intr->read_regs_enabled = 0;
	spin_unlock(&intr->lock);
}

#define urb_dev(urb) (&(urb)->dev->dev)

static inline void handle_regs_int(struct urb *urb)
{
	struct zd_usb *usb = urb->context;
	struct zd_usb_interrupt *intr = &usb->intr;
	int len;

	ZD_ASSERT(in_interrupt());
	spin_lock(&intr->lock);

	if (intr->read_regs_enabled) {
		intr->read_regs.length = len = urb->actual_length;

		if (len > sizeof(intr->read_regs.buffer))
			len = sizeof(intr->read_regs.buffer);
		memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
		intr->read_regs_enabled = 0;
		complete(&intr->read_regs.completion);
		goto out;
	}

	dev_dbg_f(urb_dev(urb), "regs interrupt ignored\n");
out:
	spin_unlock(&intr->lock);
}

static inline void handle_retry_failed_int(struct urb *urb)
{
	dev_dbg_f(urb_dev(urb), "retry failed interrupt\n");
}


static void int_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
{
	int r;
	struct usb_int_header *hdr;

	switch (urb->status) {
	case 0:
		break;
	case -ESHUTDOWN:
	case -EINVAL:
	case -ENODEV:
	case -ENOENT:
	case -ECONNRESET:
	case -EPIPE:
		goto kfree;
	default:
		goto resubmit;
	}

	if (urb->actual_length < sizeof(hdr)) {
		dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
		goto resubmit;
	}

	hdr = urb->transfer_buffer;
	if (hdr->type != USB_INT_TYPE) {
		dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
		goto resubmit;
	}

	switch (hdr->id) {
	case USB_INT_ID_REGS:
		handle_regs_int(urb);
		break;
	case USB_INT_ID_RETRY_FAILED:
		handle_retry_failed_int(urb);
		break;
	default:
		dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
			(unsigned int)hdr->id);
		goto resubmit;
	}

resubmit:
	r = usb_submit_urb(urb, GFP_ATOMIC);
	if (r) {
		dev_dbg_f(urb_dev(urb), "resubmit urb %p\n", urb);
		goto kfree;
	}
	return;
kfree:
	kfree(urb->transfer_buffer);
}

static inline int int_urb_interval(struct usb_device *udev)
{
	switch (udev->speed) {
	case USB_SPEED_HIGH:
		return 4;
	case USB_SPEED_LOW:
		return 10;
	case USB_SPEED_FULL:
	default:
		return 1;
	}
}

static inline int usb_int_enabled(struct zd_usb *usb)
{
	unsigned long flags;
	struct zd_usb_interrupt *intr = &usb->intr;
	struct urb *urb;

	spin_lock_irqsave(&intr->lock, flags);
	urb = intr->urb;
	spin_unlock_irqrestore(&intr->lock, flags);
	return urb != NULL;
}

int zd_usb_enable_int(struct zd_usb *usb)
{
	int r;
	struct usb_device *udev;
	struct zd_usb_interrupt *intr = &usb->intr;
	void *transfer_buffer = NULL;
	struct urb *urb;

	dev_dbg_f(zd_usb_dev(usb), "\n");

	urb = usb_alloc_urb(0, GFP_NOFS);
	if (!urb) {
		r = -ENOMEM;
		goto out;
	}

	ZD_ASSERT(!irqs_disabled());
	spin_lock_irq(&intr->lock);
	if (intr->urb) {
		spin_unlock_irq(&intr->lock);
		r = 0;
		goto error_free_urb;
	}
	intr->urb = urb;
	spin_unlock_irq(&intr->lock);

	/* TODO: make it a DMA buffer */
	r = -ENOMEM;
	transfer_buffer = kmalloc(USB_MAX_EP_INT_BUFFER, GFP_NOFS);
	if (!transfer_buffer) {
		dev_dbg_f(zd_usb_dev(usb),
			"couldn't allocate transfer_buffer\n");
		goto error_set_urb_null;
	}

	udev = zd_usb_to_usbdev(usb);
	usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
			 transfer_buffer, USB_MAX_EP_INT_BUFFER,
			 int_urb_complete, usb,
			 intr->interval);

	dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
	r = usb_submit_urb(urb, GFP_NOFS);
	if (r) {
		dev_dbg_f(zd_usb_dev(usb),
			 "Couldn't submit urb. Error number %d\n", r);
		goto error;
	}

	return 0;
error:
	kfree(transfer_buffer);
error_set_urb_null:
	spin_lock_irq(&intr->lock);
	intr->urb = NULL;
	spin_unlock_irq(&intr->lock);
error_free_urb:
	usb_free_urb(urb);
out:
	return r;
}

void zd_usb_disable_int(struct zd_usb *usb)
{
	unsigned long flags;
	struct zd_usb_interrupt *intr = &usb->intr;
	struct urb *urb;

	spin_lock_irqsave(&intr->lock, flags);
	urb = intr->urb;
	if (!urb) {
		spin_unlock_irqrestore(&intr->lock, flags);
		return;
	}
	intr->urb = NULL;
	spin_unlock_irqrestore(&intr->lock, flags);

	usb_kill_urb(urb);
	dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
	usb_free_urb(urb);
}

static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
			     unsigned int length)
{
	int i;
	struct zd_mac *mac = zd_usb_to_mac(usb);
	const struct rx_length_info *length_info;

	if (length < sizeof(struct rx_length_info)) {
		/* It's not a complete packet anyhow. */
		return;
	}
	length_info = (struct rx_length_info *)
		(buffer + length - sizeof(struct rx_length_info));

	/* It might be that three frames are merged into a single URB
	 * transaction. We have to check for the length info tag.
	 *
	 * While testing we discovered that length_info might be unaligned,
	 * because if USB transactions are merged, the last packet will not
	 * be padded. Unaligned access might also happen if the length_info
	 * structure is not present.
	 */
	if (get_unaligned(&length_info->tag) == cpu_to_le16(RX_LENGTH_INFO_TAG))
	{
		unsigned int l, k, n;
		for (i = 0, l = 0;; i++) {
			k = le16_to_cpu(get_unaligned(&length_info->length[i]));
			n = l+k;
			if (n > length)
				return;
			zd_mac_rx(mac, buffer+l, k);
			if (i >= 2)
				return;
			l = (n+3) & ~3;
		}
	} else {
		zd_mac_rx(mac, buffer, length);
	}
}

static void rx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
{
	struct zd_usb *usb;
	struct zd_usb_rx *rx;
	const u8 *buffer;
	unsigned int length;

	switch (urb->status) {
	case 0:
		break;
	case -ESHUTDOWN:
	case -EINVAL:
	case -ENODEV:
	case -ENOENT:
	case -ECONNRESET:
	case -EPIPE:
		return;
	default:
		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
		goto resubmit;
	}

	buffer = urb->transfer_buffer;
	length = urb->actual_length;
	usb = urb->context;
	rx = &usb->rx;

	if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
		/* If there is an old first fragment, we don't care. */
		dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
		ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
		spin_lock(&rx->lock);
		memcpy(rx->fragment, buffer, length);
		rx->fragment_length = length;
		spin_unlock(&rx->lock);
		goto resubmit;
	}

	spin_lock(&rx->lock);
	if (rx->fragment_length > 0) {
		/* We are on a second fragment, we believe */
		ZD_ASSERT(length + rx->fragment_length <=
			  ARRAY_SIZE(rx->fragment));
		dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
		memcpy(rx->fragment+rx->fragment_length, buffer, length);
		handle_rx_packet(usb, rx->fragment,
			         rx->fragment_length + length);
		rx->fragment_length = 0;
		spin_unlock(&rx->lock);
	} else {
		spin_unlock(&rx->lock);
		handle_rx_packet(usb, buffer, length);
	}

resubmit:
	usb_submit_urb(urb, GFP_ATOMIC);
}

struct urb *alloc_urb(struct zd_usb *usb)
{
	struct usb_device *udev = zd_usb_to_usbdev(usb);
	struct urb *urb;
	void *buffer;

	urb = usb_alloc_urb(0, GFP_NOFS);
	if (!urb)
		return NULL;
	buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_NOFS,
		                  &urb->transfer_dma);
	if (!buffer) {
		usb_free_urb(urb);
		return NULL;
	}

	usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
		          buffer, USB_MAX_RX_SIZE,
			  rx_urb_complete, usb);
	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	return urb;
}

void free_urb(struct urb *urb)
{
	if (!urb)
		return;
	usb_buffer_free(urb->dev, urb->transfer_buffer_length,
		        urb->transfer_buffer, urb->transfer_dma);
	usb_free_urb(urb);
}