zd_mac.c

zd1211无线网卡驱动源代码

/* zd_mac.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 <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/wireless.h>
#include <linux/usb.h>
#include <linux/jiffies.h>
#include <net/ieee80211_radiotap.h>

#include "zd_def.h"
#include "zd_chip.h"
#include "zd_mac.h"
#include "zd_ieee80211.h"
#include "zd_netdev.h"
#include "zd_rf.h"
#include "zd_util.h"

static void ieee_init(struct ieee80211_device *ieee);
static void softmac_init(struct ieee80211softmac_device *sm);

int zd_mac_init(struct zd_mac *mac,
	        struct net_device *netdev,
	        struct usb_interface *intf)
{
	struct ieee80211_device *ieee = zd_netdev_ieee80211(netdev);

	memset(mac, 0, sizeof(*mac));
	spin_lock_init(&mac->lock);
	mac->netdev = netdev;

	ieee_init(ieee);
	softmac_init(ieee80211_priv(netdev));
	zd_chip_init(&mac->chip, netdev, intf);
	return 0;
}

static int reset_channel(struct zd_mac *mac)
{
	int r;
	unsigned long flags;
	const struct channel_range *range;

	spin_lock_irqsave(&mac->lock, flags);
	range = zd_channel_range(mac->regdomain);
	if (!range->start) {
		r = -EINVAL;
		goto out;
	}
	mac->requested_channel = range->start;
	r = 0;
out:
	spin_unlock_irqrestore(&mac->lock, flags);
	return r;
}

int zd_mac_init_hw(struct zd_mac *mac, u8 device_type)
{
	int r;
	struct zd_chip *chip = &mac->chip;
	u8 addr[ETH_ALEN];
	u8 default_regdomain;

	r = zd_chip_enable_int(chip);
	if (r)
		goto out;
	r = zd_chip_init_hw(chip, device_type);
	if (r)
		goto disable_int;

	zd_get_e2p_mac_addr(chip, addr);
	r = zd_write_mac_addr(chip, addr);
	if (r)
		goto disable_int;
	ZD_ASSERT(!irqs_disabled());
	spin_lock_irq(&mac->lock);
	memcpy(mac->netdev->dev_addr, addr, ETH_ALEN);
	spin_unlock_irq(&mac->lock);

	r = zd_read_regdomain(chip, &default_regdomain);
	if (r)
		goto disable_int;
	if (!zd_regdomain_supported(default_regdomain)) {
		dev_dbg_f(zd_mac_dev(mac),
			  "Regulatory Domain %#04x is not supported.\n",
		          default_regdomain);
		r = -EINVAL;
		goto disable_int;
	}
	spin_lock_irq(&mac->lock);
	mac->regdomain = mac->default_regdomain = default_regdomain;
	spin_unlock_irq(&mac->lock);
	r = reset_channel(mac);
	if (r)
		goto disable_int;

	/* We must inform the device that we are doing encryption/decryption in
	 * software at the moment. */
	r = zd_set_encryption_type(chip, ENC_SNIFFER);
	if (r)
		goto disable_int;

	r = zd_geo_init(zd_mac_to_ieee80211(mac), mac->regdomain);
	if (r)
		goto disable_int;

	r = 0;
disable_int:
	zd_chip_disable_int(chip);
out:
	return r;
}

void zd_mac_clear(struct zd_mac *mac)
{
	/* Aquire the lock. */
	spin_lock(&mac->lock);
	spin_unlock(&mac->lock);
	zd_chip_clear(&mac->chip);
	memset(mac, 0, sizeof(*mac));
}

static int reset_mode(struct zd_mac *mac)
{
	struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
	struct zd_ioreq32 ioreqs[3] = {
		{ CR_RX_FILTER, STA_RX_FILTER },
		{ CR_SNIFFER_ON, 0U },
	};

	if (ieee->iw_mode == IW_MODE_MONITOR) {
		ioreqs[0].value = 0xffffffff;
		ioreqs[1].value = 0x1;
		ioreqs[2].value = ENC_SNIFFER;
	}

	return zd_iowrite32a(&mac->chip, ioreqs, 3);
}

int zd_mac_open(struct net_device *netdev)
{
	struct zd_mac *mac = zd_netdev_mac(netdev);
	struct zd_chip *chip = &mac->chip;
	int r;

	r = zd_chip_enable_int(chip);
	if (r < 0)
		goto out;

	r = zd_chip_set_basic_rates(chip, CR_RATES_80211B | CR_RATES_80211G);
	if (r < 0)
		goto disable_int;
	r = reset_mode(mac);
	if (r)
		goto disable_int;
	r = zd_chip_switch_radio_on(chip);
	if (r < 0)
		goto disable_int;
	r = zd_chip_set_channel(chip, mac->requested_channel);
	if (r < 0)
		goto disable_radio;
	r = zd_chip_enable_rx(chip);
	if (r < 0)
		goto disable_radio;
	r = zd_chip_enable_hwint(chip);
	if (r < 0)
		goto disable_rx;

	ieee80211softmac_start(netdev);
	return 0;
disable_rx:
	zd_chip_disable_rx(chip);
disable_radio:
	zd_chip_switch_radio_off(chip);
disable_int:
	zd_chip_disable_int(chip);
out:
	return r;
}

int zd_mac_stop(struct net_device *netdev)
{
	struct zd_mac *mac = zd_netdev_mac(netdev);
	struct zd_chip *chip = &mac->chip;

	netif_stop_queue(netdev);

	/*
	 * The order here deliberately is a little different from the open()
	 * method, since we need to make sure there is no opportunity for RX
	 * frames to be processed by softmac after we have stopped it.
	 */

	zd_chip_disable_rx(chip);
	ieee80211softmac_stop(netdev);

	zd_chip_disable_hwint(chip);
	zd_chip_switch_radio_off(chip);
	zd_chip_disable_int(chip);

	return 0;
}

int zd_mac_set_mac_address(struct net_device *netdev, void *p)
{
	int r;
	unsigned long flags;
	struct sockaddr *addr = p;
	struct zd_mac *mac = zd_netdev_mac(netdev);
	struct zd_chip *chip = &mac->chip;

	if (!is_valid_ether_addr(addr->sa_data))
		return -EADDRNOTAVAIL;

	dev_dbg_f(zd_mac_dev(mac),
		  "Setting MAC to " MAC_FMT "\n", MAC_ARG(addr->sa_data));

	r = zd_write_mac_addr(chip, addr->sa_data);
	if (r)
		return r;

	spin_lock_irqsave(&mac->lock, flags);
	memcpy(netdev->dev_addr, addr->sa_data, ETH_ALEN);
	spin_unlock_irqrestore(&mac->lock, flags);

	return 0;
}

int zd_mac_set_regdomain(struct zd_mac *mac, u8 regdomain)
{
	int r;
	u8 channel;

	ZD_ASSERT(!irqs_disabled());
	spin_lock_irq(&mac->lock);
	if (regdomain == 0) {
		regdomain = mac->default_regdomain;
	}
	if (!zd_regdomain_supported(regdomain)) {
		spin_unlock_irq(&mac->lock);
		return -EINVAL;
	}
	mac->regdomain = regdomain;
	channel = mac->requested_channel;
	spin_unlock_irq(&mac->lock);

	r = zd_geo_init(zd_mac_to_ieee80211(mac), regdomain);
	if (r)
		return r;
	if (!zd_regdomain_supports_channel(regdomain, channel)) {
		r = reset_channel(mac);
		if (r)
			return r;
	}

	return 0;
}

u8 zd_mac_get_regdomain(struct zd_mac *mac)
{
	unsigned long flags;
	u8 regdomain;

	spin_lock_irqsave(&mac->lock, flags);
	regdomain = mac->regdomain;
	spin_unlock_irqrestore(&mac->lock, flags);
	return regdomain;
}

static void set_channel(struct net_device *netdev, u8 channel)
{
	struct zd_mac *mac = zd_netdev_mac(netdev);

	dev_dbg_f(zd_mac_dev(mac), "channel %d\n", channel);

	zd_chip_set_channel(&mac->chip, channel);
}

/* TODO: Should not work in Managed mode. */
int zd_mac_request_channel(struct zd_mac *mac, u8 channel)
{
	unsigned long lock_flags;
	struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);

	if (ieee->iw_mode == IW_MODE_INFRA)
		return -EPERM;

	spin_lock_irqsave(&mac->lock, lock_flags);
	if (!zd_regdomain_supports_channel(mac->regdomain, channel)) {
		spin_unlock_irqrestore(&mac->lock, lock_flags);
		return -EINVAL;
	}
	mac->requested_channel = channel;
	spin_unlock_irqrestore(&mac->lock, lock_flags);
	if (netif_running(mac->netdev))
		return zd_chip_set_channel(&mac->chip, channel);
	else
		return 0;
}

int zd_mac_get_channel(struct zd_mac *mac, u8 *channel, u8 *flags)
{
	struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);

	*channel = zd_chip_get_channel(&mac->chip);
	if (ieee->iw_mode != IW_MODE_INFRA) {
		spin_lock_irq(&mac->lock);
		*flags = *channel == mac->requested_channel ?
			MAC_FIXED_CHANNEL : 0;
		spin_unlock(&mac->lock);
	} else {
		*flags = 0;
	}
	dev_dbg_f(zd_mac_dev(mac), "channel %u flags %u\n", *channel, *flags);
	return 0;
}

/* If wrong rate is given, we are falling back to the slowest rate: 1MBit/s */
static u8 cs_typed_rate(u8 cs_rate)
{
	static const u8 typed_rates[16] = {
		[ZD_CS_CCK_RATE_1M]	= ZD_CS_CCK|ZD_CS_CCK_RATE_1M,
		[ZD_CS_CCK_RATE_2M]	= ZD_CS_CCK|ZD_CS_CCK_RATE_2M,
		[ZD_CS_CCK_RATE_5_5M]	= ZD_CS_CCK|ZD_CS_CCK_RATE_5_5M,
		[ZD_CS_CCK_RATE_11M]	= ZD_CS_CCK|ZD_CS_CCK_RATE_11M,
		[ZD_OFDM_RATE_6M]	= ZD_CS_OFDM|ZD_OFDM_RATE_6M,
		[ZD_OFDM_RATE_9M]	= ZD_CS_OFDM|ZD_OFDM_RATE_9M,
		[ZD_OFDM_RATE_12M]	= ZD_CS_OFDM|ZD_OFDM_RATE_12M,
		[ZD_OFDM_RATE_18M]	= ZD_CS_OFDM|ZD_OFDM_RATE_18M,
		[ZD_OFDM_RATE_24M]	= ZD_CS_OFDM|ZD_OFDM_RATE_24M,
		[ZD_OFDM_RATE_36M]	= ZD_CS_OFDM|ZD_OFDM_RATE_36M,
		[ZD_OFDM_RATE_48M]	= ZD_CS_OFDM|ZD_OFDM_RATE_48M,
		[ZD_OFDM_RATE_54M]	= ZD_CS_OFDM|ZD_OFDM_RATE_54M,
	};

	ZD_ASSERT(ZD_CS_RATE_MASK == 0x0f);
	return typed_rates[cs_rate & ZD_CS_RATE_MASK];
}

/* Fallback to lowest rate, if rate is unknown. */
static u8 rate_to_cs_rate(u8 rate)
{
	switch (rate) {
	case IEEE80211_CCK_RATE_2MB:
		return ZD_CS_CCK_RATE_2M;
	case IEEE80211_CCK_RATE_5MB:
		return ZD_CS_CCK_RATE_5_5M;
	case IEEE80211_CCK_RATE_11MB:
		return ZD_CS_CCK_RATE_11M;
	case IEEE80211_OFDM_RATE_6MB:
		return ZD_OFDM_RATE_6M;
	case IEEE80211_OFDM_RATE_9MB:
		return ZD_OFDM_RATE_9M;
	case IEEE80211_OFDM_RATE_12MB:
		return ZD_OFDM_RATE_12M;
	case IEEE80211_OFDM_RATE_18MB:
		return ZD_OFDM_RATE_18M;
	case IEEE80211_OFDM_RATE_24MB:
		return ZD_OFDM_RATE_24M;
	case IEEE80211_OFDM_RATE_36MB:
		return ZD_OFDM_RATE_36M;
	case IEEE80211_OFDM_RATE_48MB:
		return ZD_OFDM_RATE_48M;
	case IEEE80211_OFDM_RATE_54MB:
		return ZD_OFDM_RATE_54M;
	}
	return ZD_CS_CCK_RATE_1M;
}

int zd_mac_set_mode(struct zd_mac *mac, u32 mode)
{
	struct ieee80211_device *ieee;

	switch (mode) {
	case IW_MODE_AUTO:
	case IW_MODE_ADHOC:
	case IW_MODE_INFRA:
		mac->netdev->type = ARPHRD_ETHER;
		break;
	case IW_MODE_MONITOR:
		mac->netdev->type = ARPHRD_IEEE80211_RADIOTAP;
		break;
	default:
		dev_dbg_f(zd_mac_dev(mac), "wrong mode %u\n", mode);
		return -EINVAL;
	}

	ieee = zd_mac_to_ieee80211(mac);
	ZD_ASSERT(!irqs_disabled());
	spin_lock_irq(&ieee->lock);
	ieee->iw_mode = mode;
	spin_unlock_irq(&ieee->lock);

	if (netif_running(mac->netdev))
		return reset_mode(mac);

	return 0;
}

int zd_mac_get_mode(struct zd_mac *mac, u32 *mode)
{
	unsigned long flags;
	struct ieee80211_device *ieee;

	ieee = zd_mac_to_ieee80211(mac);
	spin_lock_irqsave(&ieee->lock, flags);
	*mode = ieee->iw_mode;
	spin_unlock_irqrestore(&ieee->lock, flags);
	return 0;
}

int zd_mac_get_range(struct zd_mac *mac, struct iw_range *range)
{
	int i;
	const struct channel_range *channel_range;
	u8 regdomain;

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

	/* FIXME: Not so important and depends on the mode. For 802.11g
	 * usually this value is used. It seems to be that Bit/s number is
	 * given here.
	 */
	range->throughput = 27 * 1000 * 1000;

	range->max_qual.qual = 100;
	range->max_qual.level = 100;

	/* FIXME: Needs still to be tuned. */
	range->avg_qual.qual = 71;
	range->avg_qual.level = 80;

	/* FIXME: depends on standard? */
	range->min_rts = 256;
	range->max_rts = 2346;

	range->min_frag = MIN_FRAG_THRESHOLD;
	range->max_frag = MAX_FRAG_THRESHOLD;

	range->max_encoding_tokens = WEP_KEYS;
	range->num_encoding_sizes = 2;
	range->encoding_size[0] = 5;
	range->encoding_size[1] = WEP_KEY_LEN;

	range->we_version_compiled = WIRELESS_EXT;
	range->we_version_source = 20;

	ZD_ASSERT(!irqs_disabled());
	spin_lock_irq(&mac->lock);
	regdomain = mac->regdomain;
	spin_unlock_irq(&mac->lock);
	channel_range = zd_channel_range(regdomain);

	range->num_channels = channel_range->end - channel_range->start;
	range->old_num_channels = range->num_channels;
	range->num_frequency = range->num_channels;
	range->old_num_frequency = range->num_frequency;

	for (i = 0; i < range->num_frequency; i++) {
		struct iw_freq *freq = &range->freq[i];
		freq->i = channel_range->start + i;
		zd_channel_to_freq(freq, freq->i);
	}

	return 0;
}

static int zd_calc_tx_length_us(u8 *service, u8 cs_rate, u16 tx_length)
{
	static const u8 rate_divisor[] = {
		[ZD_CS_CCK_RATE_1M]	=  1,
		[ZD_CS_CCK_RATE_2M]	=  2,
		[ZD_CS_CCK_RATE_5_5M]	= 11, /* bits must be doubled */
		[ZD_CS_CCK_RATE_11M]	= 11,
		[ZD_OFDM_RATE_6M]	=  6,
		[ZD_OFDM_RATE_9M]	=  9,
		[ZD_OFDM_RATE_12M]	= 12,
		[ZD_OFDM_RATE_18M]	= 18,
		[ZD_OFDM_RATE_24M]	= 24,
		[ZD_OFDM_RATE_36M]	= 36,
		[ZD_OFDM_RATE_48M]	= 48,
		[ZD_OFDM_RATE_54M]	= 54,
	};

	u32 bits = (u32)tx_length * 8;
	u32 divisor;

	divisor = rate_divisor[cs_rate];
	if (divisor == 0)
		return -EINVAL;

	switch (cs_rate) {
	case ZD_CS_CCK_RATE_5_5M:
		bits = (2*bits) + 10; /* round up to the next integer */
		break;
	case ZD_CS_CCK_RATE_11M:
		if (service) {
			u32 t = bits % 11;
			*service &= ~ZD_PLCP_SERVICE_LENGTH_EXTENSION;
			if (0 < t && t <= 3) {
				*service |= ZD_PLCP_SERVICE_LENGTH_EXTENSION;
			}
		}
		bits += 10; /* round up to the next integer */
		break;
	}

	return bits/divisor;
}

enum {
	R2M_SHORT_PREAMBLE = 0x01,
	R2M_11A		   = 0x02,
};

static u8 cs_rate_to_modulation(u8 cs_rate, int flags)
{
	u8 modulation;

	modulation = cs_typed_rate(cs_rate);
	if (flags & R2M_SHORT_PREAMBLE) {
		switch (ZD_CS_RATE(modulation)) {
		case ZD_CS_CCK_RATE_2M:
		case ZD_CS_CCK_RATE_5_5M:
		case ZD_CS_CCK_RATE_11M:
			modulation |= ZD_CS_CCK_PREA_SHORT;
			return modulation;
		}
	}