/*
 * Linux device driver for RTL8187
 *
 * Copyright 2007 Michael Wu <flamingice@sourmilk.net>
 * Copyright 2007 Andrea Merello <andrea.merello@gmail.com>
 *
 * Based on the r8187 driver, which is:
 * Copyright 2005 Andrea Merello <andrea.merello@gmail.com>, et al.
 *
 * The driver was extended to the RTL8187B in 2008 by:
 *	Herton Ronaldo Krzesinski <herton@mandriva.com.br>
 *	Hin-Tak Leung <htl10@users.sourceforge.net>
 *	Larry Finger <Larry.Finger@lwfinger.net>
 *
 * Magic delays and register offsets below are taken from the original
 * r8187 driver sources.  Thanks to Realtek for their support!
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/usb.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/etherdevice.h>
#include <linux/eeprom_93cx6.h>
#include <linux/module.h>
#include <net/mac80211.h>

#include "rtl8187.h"
#include "rtl8225.h"
#ifdef CPTCFG_RTL8187_LEDS
#include "leds.h"
#endif
#include "rfkill.h"

MODULE_AUTHOR("Michael Wu <flamingice@sourmilk.net>");
MODULE_AUTHOR("Andrea Merello <andrea.merello@gmail.com>");
MODULE_AUTHOR("Herton Ronaldo Krzesinski <herton@mandriva.com.br>");
MODULE_AUTHOR("Hin-Tak Leung <htl10@users.sourceforge.net>");
MODULE_AUTHOR("Larry Finger <Larry.Finger@lwfinger.net>");
MODULE_DESCRIPTION("RTL8187/RTL8187B USB wireless driver");
MODULE_LICENSE("GPL");

static struct usb_device_id rtl8187_table[] = {
	/* Asus */
	{USB_DEVICE(0x0b05, 0x171d), .driver_info = DEVICE_RTL8187},
	/* Belkin */
	{USB_DEVICE(0x050d, 0x705e), .driver_info = DEVICE_RTL8187B},
	/* Realtek */
	{USB_DEVICE(0x0bda, 0x8187), .driver_info = DEVICE_RTL8187},
	{USB_DEVICE(0x0bda, 0x8189), .driver_info = DEVICE_RTL8187B},
	{USB_DEVICE(0x0bda, 0x8197), .driver_info = DEVICE_RTL8187B},
	{USB_DEVICE(0x0bda, 0x8198), .driver_info = DEVICE_RTL8187B},
	/* Surecom */
	{USB_DEVICE(0x0769, 0x11F2), .driver_info = DEVICE_RTL8187},
	/* Logitech */
	{USB_DEVICE(0x0789, 0x010C), .driver_info = DEVICE_RTL8187},
	/* Netgear */
	{USB_DEVICE(0x0846, 0x6100), .driver_info = DEVICE_RTL8187},
	{USB_DEVICE(0x0846, 0x6a00), .driver_info = DEVICE_RTL8187},
	{USB_DEVICE(0x0846, 0x4260), .driver_info = DEVICE_RTL8187B},
	/* HP */
	{USB_DEVICE(0x03f0, 0xca02), .driver_info = DEVICE_RTL8187},
	/* Sitecom */
	{USB_DEVICE(0x0df6, 0x000d), .driver_info = DEVICE_RTL8187},
	{USB_DEVICE(0x0df6, 0x0028), .driver_info = DEVICE_RTL8187B},
	{USB_DEVICE(0x0df6, 0x0029), .driver_info = DEVICE_RTL8187B},
	/* Sphairon Access Systems GmbH */
	{USB_DEVICE(0x114B, 0x0150), .driver_info = DEVICE_RTL8187},
	/* Dick Smith Electronics */
	{USB_DEVICE(0x1371, 0x9401), .driver_info = DEVICE_RTL8187},
	/* Abocom */
	{USB_DEVICE(0x13d1, 0xabe6), .driver_info = DEVICE_RTL8187},
	/* Qcom */
	{USB_DEVICE(0x18E8, 0x6232), .driver_info = DEVICE_RTL8187},
	/* AirLive */
	{USB_DEVICE(0x1b75, 0x8187), .driver_info = DEVICE_RTL8187},
	/* Linksys */
	{USB_DEVICE(0x1737, 0x0073), .driver_info = DEVICE_RTL8187B},
	{}
};

MODULE_DEVICE_TABLE(usb, rtl8187_table);

static const struct ieee80211_rate rtl818x_rates[] = {
	{ .bitrate = 10, .hw_value = 0, },
	{ .bitrate = 20, .hw_value = 1, },
	{ .bitrate = 55, .hw_value = 2, },
	{ .bitrate = 110, .hw_value = 3, },
	{ .bitrate = 60, .hw_value = 4, },
	{ .bitrate = 90, .hw_value = 5, },
	{ .bitrate = 120, .hw_value = 6, },
	{ .bitrate = 180, .hw_value = 7, },
	{ .bitrate = 240, .hw_value = 8, },
	{ .bitrate = 360, .hw_value = 9, },
	{ .bitrate = 480, .hw_value = 10, },
	{ .bitrate = 540, .hw_value = 11, },
};

static const struct ieee80211_channel rtl818x_channels[] = {
	{ .center_freq = 2412 },
	{ .center_freq = 2417 },
	{ .center_freq = 2422 },
	{ .center_freq = 2427 },
	{ .center_freq = 2432 },
	{ .center_freq = 2437 },
	{ .center_freq = 2442 },
	{ .center_freq = 2447 },
	{ .center_freq = 2452 },
	{ .center_freq = 2457 },
	{ .center_freq = 2462 },
	{ .center_freq = 2467 },
	{ .center_freq = 2472 },
	{ .center_freq = 2484 },
};

static void rtl8187_iowrite_async_cb(struct urb *urb)
{
	kfree(urb->context);
}

static void rtl8187_iowrite_async(struct rtl8187_priv *priv, __le16 addr,
				  void *data, u16 len)
{
	struct usb_ctrlrequest *dr;
	struct urb *urb;
	struct rtl8187_async_write_data {
		u8 data[4];
		struct usb_ctrlrequest dr;
	} *buf;
	int rc;

	buf = kmalloc(sizeof(*buf), GFP_ATOMIC);
	if (!buf)
		return;

	urb = usb_alloc_urb(0, GFP_ATOMIC);
	if (!urb) {
		kfree(buf);
		return;
	}

	dr = &buf->dr;

	dr->bRequestType = RTL8187_REQT_WRITE;
	dr->bRequest = RTL8187_REQ_SET_REG;
	dr->wValue = addr;
	dr->wIndex = 0;
	dr->wLength = cpu_to_le16(len);

	memcpy(buf, data, len);

	usb_fill_control_urb(urb, priv->udev, usb_sndctrlpipe(priv->udev, 0),
			     (unsigned char *)dr, buf, len,
			     rtl8187_iowrite_async_cb, buf);
	usb_anchor_urb(urb, &priv->anchored);
	rc = usb_submit_urb(urb, GFP_ATOMIC);
	if (rc < 0) {
		kfree(buf);
		usb_unanchor_urb(urb);
	}
	usb_free_urb(urb);
}

static inline void rtl818x_iowrite32_async(struct rtl8187_priv *priv,
					   __le32 *addr, u32 val)
{
	__le32 buf = cpu_to_le32(val);

	rtl8187_iowrite_async(priv, cpu_to_le16((unsigned long)addr),
			      &buf, sizeof(buf));
}

void rtl8187_write_phy(struct ieee80211_hw *dev, u8 addr, u32 data)
{
	struct rtl8187_priv *priv = dev->priv;

	data <<= 8;
	data |= addr | 0x80;

	rtl818x_iowrite8(priv, &priv->map->PHY[3], (data >> 24) & 0xFF);
	rtl818x_iowrite8(priv, &priv->map->PHY[2], (data >> 16) & 0xFF);
	rtl818x_iowrite8(priv, &priv->map->PHY[1], (data >> 8) & 0xFF);
	rtl818x_iowrite8(priv, &priv->map->PHY[0], data & 0xFF);
}

static void rtl8187_tx_cb(struct urb *urb)
{
	struct sk_buff *skb = (struct sk_buff *)urb->context;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_hw *hw = info->rate_driver_data[0];
	struct rtl8187_priv *priv = hw->priv;

	skb_pull(skb, priv->is_rtl8187b ? sizeof(struct rtl8187b_tx_hdr) :
					  sizeof(struct rtl8187_tx_hdr));
	ieee80211_tx_info_clear_status(info);

	if (!(urb->status) && !(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
		if (priv->is_rtl8187b) {
			skb_queue_tail(&priv->b_tx_status.queue, skb);

			/* queue is "full", discard last items */
			while (skb_queue_len(&priv->b_tx_status.queue) > 5) {
				struct sk_buff *old_skb;

				dev_dbg(&priv->udev->dev,
					"transmit status queue full\n");

				old_skb = skb_dequeue(&priv->b_tx_status.queue);
				ieee80211_tx_status_irqsafe(hw, old_skb);
			}
			return;
		} else {
			info->flags |= IEEE80211_TX_STAT_ACK;
		}
	}
	if (priv->is_rtl8187b)
		ieee80211_tx_status_irqsafe(hw, skb);
	else {
		/* Retry information for the RTI8187 is only available by
		 * reading a register in the device. We are in interrupt mode
		 * here, thus queue the skb and finish on a work queue. */
		skb_queue_tail(&priv->b_tx_status.queue, skb);
		ieee80211_queue_delayed_work(hw, &priv->work, 0);
	}
}

static void rtl8187_tx(struct ieee80211_hw *dev,
		       struct ieee80211_tx_control *control,
		       struct sk_buff *skb)
{
	struct rtl8187_priv *priv = dev->priv;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	struct ieee80211_hdr *tx_hdr =	(struct ieee80211_hdr *)(skb->data);
	unsigned int ep;
	void *buf;
	struct urb *urb;
	__le16 rts_dur = 0;
	u32 flags;
	int rc;

	urb = usb_alloc_urb(0, GFP_ATOMIC);
	if (!urb) {
		kfree_skb(skb);
		return;
	}

	flags = skb->len;
	flags |= RTL818X_TX_DESC_FLAG_NO_ENC;

	flags |= ieee80211_get_tx_rate(dev, info)->hw_value << 24;
	if (ieee80211_has_morefrags(tx_hdr->frame_control))
		flags |= RTL818X_TX_DESC_FLAG_MOREFRAG;

	/* HW will perform RTS-CTS when only RTS flags is set.
	 * HW will perform CTS-to-self when both RTS and CTS flags are set.
	 * RTS rate and RTS duration will be used also for CTS-to-self.
	 */
	if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) {
		flags |= RTL818X_TX_DESC_FLAG_RTS;
		flags |= ieee80211_get_rts_cts_rate(dev, info)->hw_value << 19;
		rts_dur = ieee80211_rts_duration(dev, priv->vif,
						 skb->len, info);
	} else if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT) {
		flags |= RTL818X_TX_DESC_FLAG_RTS | RTL818X_TX_DESC_FLAG_CTS;
		flags |= ieee80211_get_rts_cts_rate(dev, info)->hw_value << 19;
		rts_dur = ieee80211_ctstoself_duration(dev, priv->vif,
						 skb->len, info);
	}

	if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
		if (info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT)
			priv->seqno += 0x10;
		tx_hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
		tx_hdr->seq_ctrl |= cpu_to_le16(priv->seqno);
	}

	if (!priv->is_rtl8187b) {
		struct rtl8187_tx_hdr *hdr =
			(struct rtl8187_tx_hdr *)skb_push(skb, sizeof(*hdr));
		hdr->flags = cpu_to_le32(flags);
		hdr->len = 0;
		hdr->rts_duration = rts_dur;
		hdr->retry = cpu_to_le32((info->control.rates[0].count - 1) << 8);
		buf = hdr;

		ep = 2;
	} else {
		/* fc needs to be calculated before skb_push() */
		unsigned int epmap[4] = { 6, 7, 5, 4 };
		u16 fc = le16_to_cpu(tx_hdr->frame_control);

		struct rtl8187b_tx_hdr *hdr =
			(struct rtl8187b_tx_hdr *)skb_push(skb, sizeof(*hdr));
		struct ieee80211_rate *txrate =
			ieee80211_get_tx_rate(dev, info);
		memset(hdr, 0, sizeof(*hdr));
		hdr->flags = cpu_to_le32(flags);
		hdr->rts_duration = rts_dur;
		hdr->retry = cpu_to_le32((info->control.rates[0].count - 1) << 8);
		hdr->tx_duration =
			ieee80211_generic_frame_duration(dev, priv->vif,
							 info->band,
							 skb->len, txrate);
		buf = hdr;

		if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)
			ep = 12;
		else
			ep = epmap[skb_get_queue_mapping(skb)];
	}

	info->rate_driver_data[0] = dev;
	info->rate_driver_data[1] = urb;

	usb_fill_bulk_urb(urb, priv->udev, usb_sndbulkpipe(priv->udev, ep),
			  buf, skb->len, rtl8187_tx_cb, skb);
	urb->transfer_flags |= URB_ZERO_PACKET;
	usb_anchor_urb(urb, &priv->anchored);
	rc = usb_submit_urb(urb, GFP_ATOMIC);
	if (rc < 0) {
		usb_unanchor_urb(urb);
		kfree_skb(skb);
	}
	usb_free_urb(urb);
}

static void rtl8187_rx_cb(struct urb *urb)
{
	struct sk_buff *skb = (struct sk_buff *)urb->context;
	struct rtl8187_rx_info *info = (struct rtl8187_rx_info *)skb->cb;
	struct ieee80211_hw *dev = info->dev;
	struct rtl8187_priv *priv = dev->priv;
	struct ieee80211_rx_status rx_status = { 0 };
	int rate, signal;
	u32 flags;
	unsigned long f;

	spin_lock_irqsave(&priv->rx_queue.lock, f);
	__skb_unlink(skb, &priv->rx_queue);
	spin_unlock_irqrestore(&priv->rx_queue.lock, f);
	skb_put(skb, urb->actual_length);

	if (unlikely(urb->status)) {
		dev_kfree_skb_irq(skb);
		return;
	}

	if (!priv->is_rtl8187b) {
		struct rtl8187_rx_hdr *hdr =
			(typeof(hdr))(skb_tail_pointer(skb) - sizeof(*hdr));
		flags = le32_to_cpu(hdr->flags);
		/* As with the RTL8187B below, the AGC is used to calculate
		 * signal strength. In this case, the scaling
		 * constants are derived from the output of p54usb.
		 */
		signal = -4 - ((27 * hdr->agc) >> 6);
		rx_status.antenna = (hdr->signal >> 7) & 1;
		rx_status.mactime = le64_to_cpu(hdr->mac_time);
	} else {
		struct rtl8187b_rx_hdr *hdr =
			(typeof(hdr))(skb_tail_pointer(skb) - sizeof(*hdr));
		/* The Realtek datasheet for the RTL8187B shows that the RX
		 * header contains the following quantities: signal quality,
		 * RSSI, AGC, the received power in dB, and the measured SNR.
		 * In testing, none of these quantities show qualitative
		 * agreement with AP signal strength, except for the AGC,
		 * which is inversely proportional to the strength of the
		 * signal. In the following, the signal strength
		 * is derived from the AGC. The arbitrary scaling constants
		 * are chosen to make the results close to the values obtained
		 * for a BCM4312 using b43 as the driver. The noise is ignored
		 * for now.
		 */
		flags = le32_to_cpu(hdr->flags);
		signal = 14 - hdr->agc / 2;
		rx_status.antenna = (hdr->rssi >> 7) & 1;
		rx_status.mactime = le64_to_cpu(hdr->mac_time);
	}

	rx_status.signal = signal;
	priv->signal = signal;
	rate = (flags >> 20) & 0xF;
	skb_trim(skb, flags & 0x0FFF);
	rx_status.rate_idx = rate;
	rx_status.freq = dev->conf.chandef.chan->center_freq;
	rx_status.band = dev->conf.chandef.chan->band;
	rx_status.flag |= RX_FLAG_MACTIME_START;
	if (flags & RTL818X_RX_DESC_FLAG_SPLCP)
		rx_status.flag |= RX_FLAG_SHORTPRE;
	if (flags & RTL818X_RX_DESC_FLAG_CRC32_ERR)
		rx_status.flag |= RX_FLAG_FAILED_FCS_CRC;
	memcpy(IEEE80211_SKB_RXCB(skb), &rx_status, sizeof(rx_status));
	ieee80211_rx_irqsafe(dev, skb);

	skb = dev_alloc_skb(RTL8187_MAX_RX);
	if (unlikely(!skb)) {
		/* TODO check rx queue length and refill *somewhere* */
		return;
	}

	info = (struct rtl8187_rx_info *)skb->cb;
	info->urb = urb;
	info->dev = dev;
	urb->transfer_buffer = skb_tail_pointer(skb);
	urb->context = skb;
	skb_queue_tail(&priv->rx_queue, skb);

	usb_anchor_urb(urb, &priv->anchored);
	if (usb_submit_urb(urb, GFP_ATOMIC)) {
		usb_unanchor_urb(urb);
		skb_unlink(skb, &priv->rx_queue);
		dev_kfree_skb_irq(skb);
	}
}

static int rtl8187_init_urbs(struct ieee80211_hw *dev)
{
	struct rtl8187_priv *priv = dev->priv;
	struct urb *entry = NULL;
	struct sk_buff *skb;
	struct rtl8187_rx_info *info;
	int ret = 0;

	while (skb_queue_len(&priv->rx_queue) < 32) {
		skb = __dev_alloc_skb(RTL8187_MAX_RX, GFP_KERNEL);
		if (!skb) {
			ret = -ENOMEM;
			goto err;
		}
		entry = usb_alloc_urb(0, GFP_KERNEL);
		if (!entry) {
			ret = -ENOMEM;
			goto err;
		}
		usb_fill_bulk_urb(entry, priv->udev,
				  usb_rcvbulkpipe(priv->udev,
				  priv->is_rtl8187b ? 3 : 1),
				  skb_tail_pointer(skb),
				  RTL8187_MAX_RX, rtl8187_rx_cb, skb);
		info = (struct rtl8187_rx_info *)skb->cb;
		info->urb = entry;
		info->dev = dev;
		skb_queue_tail(&priv->rx_queue, skb);
		usb_anchor_urb(entry, &priv->anchored);
		ret = usb_submit_urb(entry, GFP_KERNEL);
		usb_put_urb(entry);
		if (ret) {
			skb_unlink(skb, &priv->rx_queue);
			usb_unanchor_urb(entry);
			goto err;
		}
	}
	return ret;

err:
	kfree_skb(skb);
	usb_kill_anchored_urbs(&priv->anchored);
	return ret;
}

static void rtl8187b_status_cb(struct urb *urb)
{
	struct ieee80211_hw *hw = (struct ieee80211_hw *)urb->context;
	struct rtl8187_priv *priv = hw->priv;
	u64 val;
	unsigned int cmd_type;

	if (unlikely(urb->status))
		return;

	/*
	 * Read from status buffer:
	 *
	 * bits [30:31] = cmd type:
	 * - 0 indicates tx beacon interrupt
	 * - 1 indicates tx close descriptor
	 *
	 * In the case of tx beacon interrupt:
	 * [0:9] = Last Beacon CW
	 * [10:29] = reserved
	 * [30:31] = 00b
	 * [32:63] = Last Beacon TSF
	 *
	 * If it's tx close descriptor:
	 * [0:7] = Packet Retry Count
	 * [8:14] = RTS Retry Count
	 * [15] = TOK
	 * [16:27] = Sequence No
	 * [28] = LS
	 * [29] = FS
	 * [30:31] = 01b
	 * [32:47] = unused (reserved?)
	 * [48:63] = MAC Used Time
	 */
	val = le64_to_cpu(priv->b_tx_status.buf);

	cmd_type = (val >> 30) & 0x3;
	if (cmd_type == 1) {
		unsigned int pkt_rc, seq_no;
		bool tok;
		struct sk_buff *skb;
		struct ieee80211_hdr *ieee80211hdr;
		unsigned long flags;

		pkt_rc = val & 0xFF;
		tok = val & (1 << 15);
		seq_no = (val >> 16) & 0xFFF;

		spin_lock_irqsave(&priv->b_tx_status.queue.lock, flags);
		skb_queue_reverse_walk(&priv->b_tx_status.queue, skb) {
			ieee80211hdr = (struct ieee80211_hdr *)skb->data;

			/*
			 * While testing, it was discovered that the seq_no
			 * doesn't actually contains the sequence number.
			 * Instead of returning just the 12 bits of sequence
			 * number, hardware is returning entire sequence control
			 * (fragment number plus sequence number) in a 12 bit
			 * only field overflowing after some time. As a
			 * workaround, just consider the lower bits, and expect
			 * it's unlikely we wrongly ack some sent data
			 */
			if ((le16_to_cpu(ieee80211hdr->seq_ctrl)
			    & 0xFFF) == seq_no)
				break;
		}
		if (skb != (struct sk_buff *) &priv->b_tx_status.queue) {
			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

			__skb_unlink(skb, &priv->b_tx_status.queue);
			if (tok)
				info->flags |= IEEE80211_TX_STAT_ACK;
			info->status.rates[0].count = pkt_rc + 1;

			ieee80211_tx_status_irqsafe(hw, skb);
		}
		spin_unlock_irqrestore(&priv->b_tx_status.queue.lock, flags);
	}

	usb_anchor_urb(urb, &priv->anchored);
	if (usb_submit_urb(urb, GFP_ATOMIC))
		usb_unanchor_urb(urb);
}

static int rtl8187b_init_status_urb(struct ieee80211_hw *dev)
{
	struct rtl8187_priv *priv = dev->priv;
	struct urb *entry;
	int ret = 0;

	entry = usb_alloc_urb(0, GFP_KERNEL);
	if (!entry)
		return -ENOMEM;

	usb_fill_bulk_urb(entry, priv->udev, usb_rcvbulkpipe(priv->udev, 9),
			  &priv->b_tx_status.buf, sizeof(priv->b_tx_status.buf),
			  rtl8187b_status_cb, dev);

	usb_anchor_urb(entry, &priv->anchored);
	ret = usb_submit_urb(entry, GFP_KERNEL);
	if (ret)
		usb_unanchor_urb(entry);
	usb_free_urb(entry);

	return ret;
}

static void rtl8187_set_anaparam(struct rtl8187_priv *priv, bool rfon)
{
	u32 anaparam, anaparam2;
	u8 anaparam3, reg;

	if (!priv->is_rtl8187b) {
		if (rfon) {
			anaparam = RTL8187_RTL8225_ANAPARAM_ON;
			anaparam2 = RTL8187_RTL8225_ANAPARAM2_ON;
		} else {
			anaparam = RTL8187_RTL8225_ANAPARAM_OFF;
			anaparam2 = RTL8187_RTL8225_ANAPARAM2_OFF;
		}
	} else {
		if (rfon) {
			anaparam = RTL8187B_RTL8225_ANAPARAM_ON;
			anaparam2 = RTL8187B_RTL8225_ANAPARAM2_ON;
			anaparam3 = RTL8187B_RTL8225_ANAPARAM3_ON;
		} else {
			anaparam = RTL8187B_RTL8225_ANAPARAM_OFF;
			anaparam2 = RTL8187B_RTL8225_ANAPARAM2_OFF;
			anaparam3 = RTL8187B_RTL8225_ANAPARAM3_OFF;
		}
	}

	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD,
			 RTL818X_EEPROM_CMD_CONFIG);
	reg = rtl818x_ioread8(priv, &priv->map->CONFIG3);
	reg |= RTL818X_CONFIG3_ANAPARAM_WRITE;
	rtl818x_iowrite8(priv, &priv->map->CONFIG3, reg);
	rtl818x_iowrite32(priv, &priv->map->ANAPARAM, anaparam);
	rtl818x_iowrite32(priv, &priv->map->ANAPARAM2, anaparam2);
	if (priv->is_rtl8187b)
		rtl818x_iowrite8(priv, &priv->map->ANAPARAM3A, anaparam3);
	reg &= ~RTL818X_CONFIG3_ANAPARAM_WRITE;
	rtl818x_iowrite8(priv, &priv->map->CONFIG3, reg);
	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD,
			 RTL818X_EEPROM_CMD_NORMAL);
}

static int rtl8187_cmd_reset(struct ieee80211_hw *dev)
{
	struct rtl8187_priv *priv = dev->priv;
	u8 reg;
	int i;

	reg = rtl818x_ioread8(priv, &priv->map->CMD);
	reg &= (1 << 1);
	reg |= RTL818X_CMD_RESET;
	rtl818x_iowrite8(priv, &priv->map->CMD, reg);

	i = 10;
	do {
		msleep(2);
		if (!(rtl818x_ioread8(priv, &priv->map->CMD) &
		      RTL818X_CMD_RESET))
			break;
	} while (--i);

	if (!i) {
		wiphy_err(dev->wiphy, "Reset timeout!\n");
		return -ETIMEDOUT;
	}

	/* reload registers from eeprom */
	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD, RTL818X_EEPROM_CMD_LOAD);

	i = 10;
	do {
		msleep(4);
		if (!(rtl818x_ioread8(priv, &priv->map->EEPROM_CMD) &
		      RTL818X_EEPROM_CMD_CONFIG))
			break;
	} while (--i);

	if (!i) {
		wiphy_err(dev->wiphy, "eeprom reset timeout!\n");
		return -ETIMEDOUT;
	}

	return 0;
}

static int rtl8187_init_hw(struct ieee80211_hw *dev)
{
	struct rtl8187_priv *priv = dev->priv;
	u8 reg;
	int res;

	/* reset */
	rtl8187_set_anaparam(priv, true);

	rtl818x_iowrite16(priv, &priv->map->INT_MASK, 0);

	msleep(200);
	rtl818x_iowrite8(priv, (u8 *)0xFE18, 0x10);
	rtl818x_iowrite8(priv, (u8 *)0xFE18, 0x11);
	rtl818x_iowrite8(priv, (u8 *)0xFE18, 0x00);
	msleep(200);

	res = rtl8187_cmd_reset(dev);
	if (res)
		return res;

	rtl8187_set_anaparam(priv, true);

	/* setup card */
	rtl818x_iowrite16(priv, &priv->map->RFPinsSelect, 0);
	rtl818x_iowrite8(priv, &priv->map->GPIO0, 0);

	rtl818x_iowrite16(priv, &priv->map->RFPinsSelect, (4 << 8));
	rtl818x_iowrite8(priv, &priv->map->GPIO0, 1);
	rtl818x_iowrite8(priv, &priv->map->GP_ENABLE, 0);

	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD, RTL818X_EEPROM_CMD_CONFIG);

	rtl818x_iowrite16(priv, (__le16 *)0xFFF4, 0xFFFF);
	reg = rtl818x_ioread8(priv, &priv->map->CONFIG1);
	reg &= 0x3F;
	reg |= 0x80;
	rtl818x_iowrite8(priv, &priv->map->CONFIG1, reg);

	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD, RTL818X_EEPROM_CMD_NORMAL);

	rtl818x_iowrite32(priv, &priv->map->INT_TIMEOUT, 0);
	rtl818x_iowrite8(priv, &priv->map->WPA_CONF, 0);
	rtl818x_iowrite8(priv, &priv->map->RATE_FALLBACK, 0);

	// TODO: set RESP_RATE and BRSR properly
	rtl818x_iowrite8(priv, &priv->map->RESP_RATE, (8 << 4) | 0);
	rtl818x_iowrite16(priv, &priv->map->BRSR, 0x01F3);

	/* host_usb_init */
	rtl818x_iowrite16(priv, &priv->map->RFPinsSelect, 0);
	rtl818x_iowrite8(priv, &priv->map->GPIO0, 0);
	reg = rtl818x_ioread8(priv, (u8 *)0xFE53);
	rtl818x_iowrite8(priv, (u8 *)0xFE53, reg | (1 << 7));
	rtl818x_iowrite16(priv, &priv->map->RFPinsSelect, (4 << 8));
	rtl818x_iowrite8(priv, &priv->map->GPIO0, 0x20);
	rtl818x_iowrite8(priv, &priv->map->GP_ENABLE, 0);
	rtl818x_iowrite16(priv, &priv->map->RFPinsOutput, 0x80);
	rtl818x_iowrite16(priv, &priv->map->RFPinsSelect, 0x80);
	rtl818x_iowrite16(priv, &priv->map->RFPinsEnable, 0x80);
	msleep(100);

	rtl818x_iowrite32(priv, &priv->map->RF_TIMING, 0x000a8008);
	rtl818x_iowrite16(priv, &priv->map->BRSR, 0xFFFF);
	rtl818x_iowrite32(priv, &priv->map->RF_PARA, 0x00100044);
	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD,
			 RTL818X_EEPROM_CMD_CONFIG);
	rtl818x_iowrite8(priv, &priv->map->CONFIG3, 0x44);
	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD,
			 RTL818X_EEPROM_CMD_NORMAL);
	rtl818x_iowrite16(priv, &priv->map->RFPinsEnable, 0x1FF7);
	msleep(100);

	priv->rf->init(dev);

	rtl818x_iowrite16(priv, &priv->map->BRSR, 0x01F3);
	reg = rtl818x_ioread8(priv, &priv->map->PGSELECT) & ~1;
	rtl818x_iowrite8(priv, &priv->map->PGSELECT, reg | 1);
	rtl818x_iowrite16(priv, (__le16 *)0xFFFE, 0x10);
	rtl818x_iowrite8(priv, &priv->map->TALLY_SEL, 0x80);
	rtl818x_iowrite8(priv, (u8 *)0xFFFF, 0x60);
	rtl818x_iowrite8(priv, &priv->map->PGSELECT, reg);

	return 0;
}

static const u8 rtl8187b_reg_table[][3] = {
	{0xF0, 0x32, 0}, {0xF1, 0x32, 0}, {0xF2, 0x00, 0}, {0xF3, 0x00, 0},
	{0xF4, 0x32, 0}, {0xF5, 0x43, 0}, {0xF6, 0x00, 0}, {0xF7, 0x00, 0},
	{0xF8, 0x46, 0}, {0xF9, 0xA4, 0}, {0xFA, 0x00, 0}, {0xFB, 0x00, 0},
	{0xFC, 0x96, 0}, {0xFD, 0xA4, 0}, {0xFE, 0x00, 0}, {0xFF, 0x00, 0},

	{0x58, 0x4B, 1}, {0x59, 0x00, 1}, {0x5A, 0x4B, 1}, {0x5B, 0x00, 1},
	{0x60, 0x4B, 1}, {0x61, 0x09, 1}, {0x62, 0x4B, 1}, {0x63, 0x09, 1},
	{0xCE, 0x0F, 1}, {0xCF, 0x00, 1}, {0xF0, 0x4E, 1}, {0xF1, 0x01, 1},
	{0xF2, 0x02, 1}, {0xF3, 0x03, 1}, {0xF4, 0x04, 1}, {0xF5, 0x05, 1},
	{0xF6, 0x06, 1}, {0xF7, 0x07, 1}, {0xF8, 0x08, 1},

	{0x4E, 0x00, 2}, {0x0C, 0x04, 2}, {0x21, 0x61, 2}, {0x22, 0x68, 2},
	{0x23, 0x6F, 2}, {0x24, 0x76, 2}, {0x25, 0x7D, 2}, {0x26, 0x84, 2},
	{0x27, 0x8D, 2}, {0x4D, 0x08, 2}, {0x50, 0x05, 2}, {0x51, 0xF5, 2},
	{0x52, 0x04, 2}, {0x53, 0xA0, 2}, {0x54, 0x1F, 2}, {0x55, 0x23, 2},
	{0x56, 0x45, 2}, {0x57, 0x67, 2}, {0x58, 0x08, 2}, {0x59, 0x08, 2},
	{0x5A, 0x08, 2}, {0x5B, 0x08, 2}, {0x60, 0x08, 2}, {0x61, 0x08, 2},
	{0x62, 0x08, 2}, {0x63, 0x08, 2}, {0x64, 0xCF, 2},

	{0x5B, 0x40, 0}, {0x84, 0x88, 0}, {0x85, 0x24, 0}, {0x88, 0x54, 0},
	{0x8B, 0xB8, 0}, {0x8C, 0x07, 0}, {0x8D, 0x00, 0}, {0x94, 0x1B, 0},
	{0x95, 0x12, 0}, {0x96, 0x00, 0}, {0x97, 0x06, 0}, {0x9D, 0x1A, 0},
	{0x9F, 0x10, 0}, {0xB4, 0x22, 0}, {0xBE, 0x80, 0}, {0xDB, 0x00, 0},
	{0xEE, 0x00, 0}, {0x4C, 0x00, 2},

	{0x9F, 0x00, 3}, {0x8C, 0x01, 0}, {0x8D, 0x10, 0}, {0x8E, 0x08, 0},
	{0x8F, 0x00, 0}
};

static int rtl8187b_init_hw(struct ieee80211_hw *dev)
{
	struct rtl8187_priv *priv = dev->priv;
	int res, i;
	u8 reg;

	rtl8187_set_anaparam(priv, true);

	/* Reset PLL sequence on 8187B. Realtek note: reduces power
	 * consumption about 30 mA */
	rtl818x_iowrite8(priv, (u8 *)0xFF61, 0x10);
	reg = rtl818x_ioread8(priv, (u8 *)0xFF62);
	rtl818x_iowrite8(priv, (u8 *)0xFF62, reg & ~(1 << 5));
	rtl818x_iowrite8(priv, (u8 *)0xFF62, reg | (1 << 5));

	res = rtl8187_cmd_reset(dev);
	if (res)
		return res;

	rtl8187_set_anaparam(priv, true);

	/* BRSR (Basic Rate Set Register) on 8187B looks to be the same as
	 * RESP_RATE on 8187L in Realtek sources: each bit should be each
	 * one of the 12 rates, all are enabled */
	rtl818x_iowrite16(priv, (__le16 *)0xFF34, 0x0FFF);

	reg = rtl818x_ioread8(priv, &priv->map->CW_CONF);
	reg |= RTL818X_CW_CONF_PERPACKET_RETRY;
	rtl818x_iowrite8(priv, &priv->map->CW_CONF, reg);

	/* Auto Rate Fallback Register (ARFR): 1M-54M setting */
	rtl818x_iowrite16_idx(priv, (__le16 *)0xFFE0, 0x0FFF, 1);
	rtl818x_iowrite8_idx(priv, (u8 *)0xFFE2, 0x00, 1);

	rtl818x_iowrite16_idx(priv, (__le16 *)0xFFD4, 0xFFFF, 1);

	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD,
			 RTL818X_EEPROM_CMD_CONFIG);
	reg = rtl818x_ioread8(priv, &priv->map->CONFIG1);
	rtl818x_iowrite8(priv, &priv->map->CONFIG1, (reg & 0x3F) | 0x80);
	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD,
			 RTL818X_EEPROM_CMD_NORMAL);

	rtl818x_iowrite8(priv, &priv->map->WPA_CONF, 0);
	for (i = 0; i < ARRAY_SIZE(rtl8187b_reg_table); i++) {
		rtl818x_iowrite8_idx(priv,
				     (u8 *)(uintptr_t)
				     (rtl8187b_reg_table[i][0] | 0xFF00),
				     rtl8187b_reg_table[i][1],
				     rtl8187b_reg_table[i][2]);
	}

	rtl818x_iowrite16(priv, &priv->map->TID_AC_MAP, 0xFA50);
	rtl818x_iowrite16(priv, &priv->map->INT_MIG, 0);

	rtl818x_iowrite32_idx(priv, (__le32 *)0xFFF0, 0, 1);
	rtl818x_iowrite32_idx(priv, (__le32 *)0xFFF4, 0, 1);
	rtl818x_iowrite8_idx(priv, (u8 *)0xFFF8, 0, 1);

	rtl818x_iowrite32(priv, &priv->map->RF_TIMING, 0x00004001);

	/* RFSW_CTRL register */
	rtl818x_iowrite16_idx(priv, (__le16 *)0xFF72, 0x569A, 2);

	rtl818x_iowrite16(priv, &priv->map->RFPinsOutput, 0x0480);
	rtl818x_iowrite16(priv, &priv->map->RFPinsSelect, 0x2488);
	rtl818x_iowrite16(priv, &priv->map->RFPinsEnable, 0x1FFF);
	msleep(100);

	priv->rf->init(dev);

	reg = RTL818X_CMD_TX_ENABLE | RTL818X_CMD_RX_ENABLE;
	rtl818x_iowrite8(priv, &priv->map->CMD, reg);
	rtl818x_iowrite16(priv, &priv->map->INT_MASK, 0xFFFF);

	rtl818x_iowrite8(priv, (u8 *)0xFE41, 0xF4);
	rtl818x_iowrite8(priv, (u8 *)0xFE40, 0x00);
	rtl818x_iowrite8(priv, (u8 *)0xFE42, 0x00);
	rtl818x_iowrite8(priv, (u8 *)0xFE42, 0x01);
	rtl818x_iowrite8(priv, (u8 *)0xFE40, 0x0F);
	rtl818x_iowrite8(priv, (u8 *)0xFE42, 0x00);
	rtl818x_iowrite8(priv, (u8 *)0xFE42, 0x01);

	reg = rtl818x_ioread8(priv, (u8 *)0xFFDB);
	rtl818x_iowrite8(priv, (u8 *)0xFFDB, reg | (1 << 2));
	rtl818x_iowrite16_idx(priv, (__le16 *)0xFF72, 0x59FA, 3);
	rtl818x_iowrite16_idx(priv, (__le16 *)0xFF74, 0x59D2, 3);
	rtl818x_iowrite16_idx(priv, (__le16 *)0xFF76, 0x59D2, 3);
	rtl818x_iowrite16_idx(priv, (__le16 *)0xFF78, 0x19FA, 3);
	rtl818x_iowrite16_idx(priv, (__le16 *)0xFF7A, 0x19FA, 3);
	rtl818x_iowrite16_idx(priv, (__le16 *)0xFF7C, 0x00D0, 3);
	rtl818x_iowrite8(priv, (u8 *)0xFF61, 0);
	rtl818x_iowrite8_idx(priv, (u8 *)0xFF80, 0x0F, 1);
	rtl818x_iowrite8_idx(priv, (u8 *)0xFF83, 0x03, 1);
	rtl818x_iowrite8(priv, (u8 *)0xFFDA, 0x10);
	rtl818x_iowrite8_idx(priv, (u8 *)0xFF4D, 0x08, 2);

	rtl818x_iowrite32(priv, &priv->map->HSSI_PARA, 0x0600321B);

	rtl818x_iowrite16_idx(priv, (__le16 *)0xFFEC, 0x0800, 1);

	priv->slot_time = 0x9;
	priv->aifsn[0] = 2; /* AIFSN[AC_VO] */
	priv->aifsn[1] = 2; /* AIFSN[AC_VI] */
	priv->aifsn[2] = 7; /* AIFSN[AC_BK] */
	priv->aifsn[3] = 3; /* AIFSN[AC_BE] */
	rtl818x_iowrite8(priv, &priv->map->ACM_CONTROL, 0);

	/* ENEDCA flag must always be set, transmit issues? */
	rtl818x_iowrite8(priv, &priv->map->MSR, RTL818X_MSR_ENEDCA);

	return 0;
}

static void rtl8187_work(struct work_struct *work)
{
	/* The RTL8187 returns the retry count through register 0xFFFA. In
	 * addition, it appears to be a cumulative retry count, not the
	 * value for the current TX packet. When multiple TX entries are
	 * waiting in the queue, the retry count will be the total for all.
	 * The "error" may matter for purposes of rate setting, but there is
	 * no other choice with this hardware.
	 */
	struct rtl8187_priv *priv = container_of(work, struct rtl8187_priv,
				    work.work);
	struct ieee80211_tx_info *info;
	struct ieee80211_hw *dev = priv->dev;
	static u16 retry;
	u16 tmp;
	u16 avg_retry;
	int length;

	mutex_lock(&priv->conf_mutex);
	tmp = rtl818x_ioread16(priv, (__le16 *)0xFFFA);
	length = skb_queue_len(&priv->b_tx_status.queue);
	if (unlikely(!length))
		length = 1;
	if (unlikely(tmp < retry))
		tmp = retry;
	avg_retry = (tmp - retry) / length;
	while (skb_queue_len(&priv->b_tx_status.queue) > 0) {
		struct sk_buff *old_skb;

		old_skb = skb_dequeue(&priv->b_tx_status.queue);
		info = IEEE80211_SKB_CB(old_skb);
		info->status.rates[0].count = avg_retry + 1;
		if (info->status.rates[0].count > RETRY_COUNT)
			info->flags &= ~IEEE80211_TX_STAT_ACK;
		ieee80211_tx_status_irqsafe(dev, old_skb);
	}
	retry = tmp;
	mutex_unlock(&priv->conf_mutex);
}

static int rtl8187_start(struct ieee80211_hw *dev)
{
	struct rtl8187_priv *priv = dev->priv;
	u32 reg;
	int ret;

	mutex_lock(&priv->conf_mutex);

	ret = (!priv->is_rtl8187b) ? rtl8187_init_hw(dev) :
				     rtl8187b_init_hw(dev);
	if (ret)
		goto rtl8187_start_exit;

	init_usb_anchor(&priv->anchored);
	priv->dev = dev;

	if (priv->is_rtl8187b) {
		reg = RTL818X_RX_CONF_MGMT |
		      RTL818X_RX_CONF_DATA |
		      RTL818X_RX_CONF_BROADCAST |
		      RTL818X_RX_CONF_NICMAC |
		      RTL818X_RX_CONF_BSSID |
		      (7 << 13 /* RX FIFO threshold NONE */) |
		      (7 << 10 /* MAX RX DMA */) |
		      RTL818X_RX_CONF_RX_AUTORESETPHY |
		      RTL818X_RX_CONF_ONLYERLPKT |
		      RTL818X_RX_CONF_MULTICAST;
		priv->rx_conf = reg;
		rtl818x_iowrite32(priv, &priv->map->RX_CONF, reg);

		reg = rtl818x_ioread8(priv, &priv->map->TX_AGC_CTL);
		reg &= ~RTL818X_TX_AGC_CTL_PERPACKET_GAIN;
		reg &= ~RTL818X_TX_AGC_CTL_PERPACKET_ANTSEL;
		reg &= ~RTL818X_TX_AGC_CTL_FEEDBACK_ANT;
		rtl818x_iowrite8(priv, &priv->map->TX_AGC_CTL, reg);

		rtl818x_iowrite32(priv, &priv->map->TX_CONF,
				  RTL818X_TX_CONF_HW_SEQNUM |
				  RTL818X_TX_CONF_DISREQQSIZE |
				  (RETRY_COUNT << 8  /* short retry limit */) |
				  (RETRY_COUNT << 0  /* long retry limit */) |
				  (7 << 21 /* MAX TX DMA */));
		ret = rtl8187_init_urbs(dev);
		if (ret)
			goto rtl8187_start_exit;
		ret = rtl8187b_init_status_urb(dev);
		if (ret)
			usb_kill_anchored_urbs(&priv->anchored);
		goto rtl8187_start_exit;
	}

	rtl818x_iowrite16(priv, &priv->map->INT_MASK, 0xFFFF);

	rtl818x_iowrite32(priv, &priv->map->MAR[0], ~0);
	rtl818x_iowrite32(priv, &priv->map->MAR[1], ~0);

	ret = rtl8187_init_urbs(dev);
	if (ret)
		goto rtl8187_start_exit;

	reg = RTL818X_RX_CONF_ONLYERLPKT |
	      RTL818X_RX_CONF_RX_AUTORESETPHY |
	      RTL818X_RX_CONF_BSSID |
	      RTL818X_RX_CONF_MGMT |
	      RTL818X_RX_CONF_DATA |
	      (7 << 13 /* RX FIFO threshold NONE */) |
	      (7 << 10 /* MAX RX DMA */) |
	      RTL818X_RX_CONF_BROADCAST |
	      RTL818X_RX_CONF_NICMAC;

	priv->rx_conf = reg;
	rtl818x_iowrite32(priv, &priv->map->RX_CONF, reg);

	reg = rtl818x_ioread8(priv, &priv->map->CW_CONF);
	reg &= ~RTL818X_CW_CONF_PERPACKET_CW;
	reg |= RTL818X_CW_CONF_PERPACKET_RETRY;
	rtl818x_iowrite8(priv, &priv->map->CW_CONF, reg);

	reg = rtl818x_ioread8(priv, &priv->map->TX_AGC_CTL);
	reg &= ~RTL818X_TX_AGC_CTL_PERPACKET_GAIN;
	reg &= ~RTL818X_TX_AGC_CTL_PERPACKET_ANTSEL;
	reg &= ~RTL818X_TX_AGC_CTL_FEEDBACK_ANT;
	rtl818x_iowrite8(priv, &priv->map->TX_AGC_CTL, reg);

	reg  = RTL818X_TX_CONF_CW_MIN |
	       (7 << 21 /* MAX TX DMA */) |
	       RTL818X_TX_CONF_NO_ICV;
	rtl818x_iowrite32(priv, &priv->map->TX_CONF, reg);

	reg = rtl818x_ioread8(priv, &priv->map->CMD);
	reg |= RTL818X_CMD_TX_ENABLE;
	reg |= RTL818X_CMD_RX_ENABLE;
	rtl818x_iowrite8(priv, &priv->map->CMD, reg);
	INIT_DELAYED_WORK(&priv->work, rtl8187_work);

rtl8187_start_exit:
	mutex_unlock(&priv->conf_mutex);
	return ret;
}

static void rtl8187_stop(struct ieee80211_hw *dev)
{
	struct rtl8187_priv *priv = dev->priv;
	struct sk_buff *skb;
	u32 reg;

	mutex_lock(&priv->conf_mutex);
	rtl818x_iowrite16(priv, &priv->map->INT_MASK, 0);

	reg = rtl818x_ioread8(priv, &priv->map->CMD);
	reg &= ~RTL818X_CMD_TX_ENABLE;
	reg &= ~RTL818X_CMD_RX_ENABLE;
	rtl818x_iowrite8(priv, &priv->map->CMD, reg);

	priv->rf->stop(dev);
	rtl8187_set_anaparam(priv, false);

	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD, RTL818X_EEPROM_CMD_CONFIG);
	reg = rtl818x_ioread8(priv, &priv->map->CONFIG4);
	rtl818x_iowrite8(priv, &priv->map->CONFIG4, reg | RTL818X_CONFIG4_VCOOFF);
	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD, RTL818X_EEPROM_CMD_NORMAL);

	while ((skb = skb_dequeue(&priv->b_tx_status.queue)))
		dev_kfree_skb_any(skb);

	usb_kill_anchored_urbs(&priv->anchored);
	mutex_unlock(&priv->conf_mutex);

	if (!priv->is_rtl8187b)
		cancel_delayed_work_sync(&priv->work);
}

static u64 rtl8187_get_tsf(struct ieee80211_hw *dev, struct ieee80211_vif *vif)
{
	struct rtl8187_priv *priv = dev->priv;

	return rtl818x_ioread32(priv, &priv->map->TSFT[0]) |
	       (u64)(rtl818x_ioread32(priv, &priv->map->TSFT[1])) << 32;
}


static void rtl8187_beacon_work(struct work_struct *work)
{
	struct rtl8187_vif *vif_priv =
		container_of(work, struct rtl8187_vif, beacon_work.work);
	struct ieee80211_vif *vif =
		container_of((void *)vif_priv, struct ieee80211_vif, drv_priv);
	struct ieee80211_hw *dev = vif_priv->dev;
	struct ieee80211_mgmt *mgmt;
	struct sk_buff *skb;

	/* don't overflow the tx ring */
	if (ieee80211_queue_stopped(dev, 0))
		goto resched;

	/* grab a fresh beacon */
	skb = ieee80211_beacon_get(dev, vif);
	if (!skb)
		goto resched;

	/*
	 * update beacon timestamp w/ TSF value
	 * TODO: make hardware update beacon timestamp
	 */
	mgmt = (struct ieee80211_mgmt *)skb->data;
	mgmt->u.beacon.timestamp = cpu_to_le64(rtl8187_get_tsf(dev, vif));

	/* TODO: use actual beacon queue */
	skb_set_queue_mapping(skb, 0);

	rtl8187_tx(dev, NULL, skb);

resched:
	/*
	 * schedule next beacon
	 * TODO: use hardware support for beacon timing
	 */
	schedule_delayed_work(&vif_priv->beacon_work,
			usecs_to_jiffies(1024 * vif->bss_conf.beacon_int));
}


static int rtl8187_add_interface(struct ieee80211_hw *dev,
				 struct ieee80211_vif *vif)
{
	struct rtl8187_priv *priv = dev->priv;
	struct rtl8187_vif *vif_priv;
	int i;
	int ret = -EOPNOTSUPP;

	mutex_lock(&priv->conf_mutex);
	if (priv->vif)
		goto exit;

	switch (vif->type) {
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_ADHOC:
		break;
	default:
		goto exit;
	}

	ret = 0;
	priv->vif = vif;

	/* Initialize driver private area */
	vif_priv = (struct rtl8187_vif *)&vif->drv_priv;
	vif_priv->dev = dev;
	INIT_DELAYED_WORK(&vif_priv->beacon_work, rtl8187_beacon_work);
	vif_priv->enable_beacon = false;


	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD, RTL818X_EEPROM_CMD_CONFIG);
	for (i = 0; i < ETH_ALEN; i++)
		rtl818x_iowrite8(priv, &priv->map->MAC[i],
				 ((u8 *)vif->addr)[i]);
	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD, RTL818X_EEPROM_CMD_NORMAL);

exit:
	mutex_unlock(&priv->conf_mutex);
	return ret;
}

static void rtl8187_remove_interface(struct ieee80211_hw *dev,
				     struct ieee80211_vif *vif)
{
	struct rtl8187_priv *priv = dev->priv;
	mutex_lock(&priv->conf_mutex);
	priv->vif = NULL;
	mutex_unlock(&priv->conf_mutex);
}

static int rtl8187_config(struct ieee80211_hw *dev, u32 changed)
{
	struct rtl8187_priv *priv = dev->priv;
	struct ieee80211_conf *conf = &dev->conf;
	u32 reg;

	mutex_lock(&priv->conf_mutex);
	reg = rtl818x_ioread32(priv, &priv->map->TX_CONF);
	/* Enable TX loopback on MAC level to avoid TX during channel
	 * changes, as this has be seen to causes problems and the
	 * card will stop work until next reset
	 */
	rtl818x_iowrite32(priv, &priv->map->TX_CONF,
			  reg | RTL818X_TX_CONF_LOOPBACK_MAC);
	priv->rf->set_chan(dev, conf);
	msleep(10);
	rtl818x_iowrite32(priv, &priv->map->TX_CONF, reg);

	rtl818x_iowrite16(priv, &priv->map->ATIM_WND, 2);
	rtl818x_iowrite16(priv, &priv->map->ATIMTR_INTERVAL, 100);
	rtl818x_iowrite16(priv, &priv->map->BEACON_INTERVAL, 100);
	rtl818x_iowrite16(priv, &priv->map->BEACON_INTERVAL_TIME, 100);
	mutex_unlock(&priv->conf_mutex);
	return 0;
}

/*
 * With 8187B, AC_*_PARAM clashes with FEMR definition in struct rtl818x_csr for
 * example. Thus we have to use raw values for AC_*_PARAM register addresses.
 */
static __le32 *rtl8187b_ac_addr[4] = {
	(__le32 *) 0xFFF0, /* AC_VO */
	(__le32 *) 0xFFF4, /* AC_VI */
	(__le32 *) 0xFFFC, /* AC_BK */
	(__le32 *) 0xFFF8, /* AC_BE */
};

#define SIFS_TIME 0xa

static void rtl8187_conf_erp(struct rtl8187_priv *priv, bool use_short_slot,
			     bool use_short_preamble)
{
	if (priv->is_rtl8187b) {
		u8 difs, eifs;
		u16 ack_timeout;
		int queue;

		if (use_short_slot) {
			priv->slot_time = 0x9;
			difs = 0x1c;
			eifs = 0x53;
		} else {
			priv->slot_time = 0x14;
			difs = 0x32;
			eifs = 0x5b;
		}
		rtl818x_iowrite8(priv, &priv->map->SIFS, 0x22);
		rtl818x_iowrite8(priv, &priv->map->SLOT, priv->slot_time);
		rtl818x_iowrite8(priv, &priv->map->DIFS, difs);

		/*
		 * BRSR+1 on 8187B is in fact EIFS register
		 * Value in units of 4 us
		 */
		rtl818x_iowrite8(priv, (u8 *)&priv->map->BRSR + 1, eifs);

		/*
		 * For 8187B, CARRIER_SENSE_COUNTER is in fact ack timeout
		 * register. In units of 4 us like eifs register
		 * ack_timeout = ack duration + plcp + difs + preamble
		 */
		ack_timeout = 112 + 48 + difs;
		if (use_short_preamble)
			ack_timeout += 72;
		else
			ack_timeout += 144;
		rtl818x_iowrite8(priv, &priv->map->CARRIER_SENSE_COUNTER,
				 DIV_ROUND_UP(ack_timeout, 4));

		for (queue = 0; queue < 4; queue++)
			rtl818x_iowrite8(priv, (u8 *) rtl8187b_ac_addr[queue],
					 priv->aifsn[queue] * priv->slot_time +
					 SIFS_TIME);
	} else {
		rtl818x_iowrite8(priv, &priv->map->SIFS, 0x22);
		if (use_short_slot) {
			rtl818x_iowrite8(priv, &priv->map->SLOT, 0x9);
			rtl818x_iowrite8(priv, &priv->map->DIFS, 0x14);
			rtl818x_iowrite8(priv, &priv->map->EIFS, 91 - 0x14);
		} else {
			rtl818x_iowrite8(priv, &priv->map->SLOT, 0x14);
			rtl818x_iowrite8(priv, &priv->map->DIFS, 0x24);
			rtl818x_iowrite8(priv, &priv->map->EIFS, 91 - 0x24);
		}
	}
}

static void rtl8187_bss_info_changed(struct ieee80211_hw *dev,
				     struct ieee80211_vif *vif,
				     struct ieee80211_bss_conf *info,
				     u32 changed)
{
	struct rtl8187_priv *priv = dev->priv;
	struct rtl8187_vif *vif_priv;
	int i;
	u8 reg;

	vif_priv = (struct rtl8187_vif *)&vif->drv_priv;

	if (changed & BSS_CHANGED_BSSID) {
		mutex_lock(&priv->conf_mutex);
		for (i = 0; i < ETH_ALEN; i++)
			rtl818x_iowrite8(priv, &priv->map->BSSID[i],
					 info->bssid[i]);

		if (priv->is_rtl8187b)
			reg = RTL818X_MSR_ENEDCA;
		else
			reg = 0;

		if (is_valid_ether_addr(info->bssid)) {
			if (vif->type == NL80211_IFTYPE_ADHOC)
				reg |= RTL818X_MSR_ADHOC;
			else
				reg |= RTL818X_MSR_INFRA;
		}
		else
			reg |= RTL818X_MSR_NO_LINK;

		rtl818x_iowrite8(priv, &priv->map->MSR, reg);

		mutex_unlock(&priv->conf_mutex);
	}

	if (changed & (BSS_CHANGED_ERP_SLOT | BSS_CHANGED_ERP_PREAMBLE))
		rtl8187_conf_erp(priv, info->use_short_slot,
				 info->use_short_preamble);

	if (changed & BSS_CHANGED_BEACON_ENABLED)
		vif_priv->enable_beacon = info->enable_beacon;

	if (changed & (BSS_CHANGED_BEACON_ENABLED | BSS_CHANGED_BEACON)) {
		cancel_delayed_work_sync(&vif_priv->beacon_work);
		if (vif_priv->enable_beacon)
			schedule_work(&vif_priv->beacon_work.work);
	}

}

static u64 rtl8187_prepare_multicast(struct ieee80211_hw *dev,
				     struct netdev_hw_addr_list *mc_list)
{
	return netdev_hw_addr_list_count(mc_list);
}

static void rtl8187_configure_filter(struct ieee80211_hw *dev,
				     unsigned int changed_flags,
				     unsigned int *total_flags,
				     u64 multicast)
{
	struct rtl8187_priv *priv = dev->priv;

	if (changed_flags & FIF_FCSFAIL)
		priv->rx_conf ^= RTL818X_RX_CONF_FCS;
	if (changed_flags & FIF_CONTROL)
		priv->rx_conf ^= RTL818X_RX_CONF_CTRL;
	if (changed_flags & FIF_OTHER_BSS)
		priv->rx_conf ^= RTL818X_RX_CONF_MONITOR;
	if (*total_flags & FIF_ALLMULTI || multicast > 0)
		priv->rx_conf |= RTL818X_RX_CONF_MULTICAST;
	else
		priv->rx_conf &= ~RTL818X_RX_CONF_MULTICAST;

	*total_flags = 0;

	if (priv->rx_conf & RTL818X_RX_CONF_FCS)
		*total_flags |= FIF_FCSFAIL;
	if (priv->rx_conf & RTL818X_RX_CONF_CTRL)
		*total_flags |= FIF_CONTROL;
	if (priv->rx_conf & RTL818X_RX_CONF_MONITOR)
		*total_flags |= FIF_OTHER_BSS;
	if (priv->rx_conf & RTL818X_RX_CONF_MULTICAST)
		*total_flags |= FIF_ALLMULTI;

	rtl818x_iowrite32_async(priv, &priv->map->RX_CONF, priv->rx_conf);
}

static int rtl8187_conf_tx(struct ieee80211_hw *dev,
			   struct ieee80211_vif *vif, u16 queue,
			   const struct ieee80211_tx_queue_params *params)
{
	struct rtl8187_priv *priv = dev->priv;
	u8 cw_min, cw_max;

	if (queue > 3)
		return -EINVAL;

	cw_min = fls(params->cw_min);
	cw_max = fls(params->cw_max);

	if (priv->is_rtl8187b) {
		priv->aifsn[queue] = params->aifs;

		/*
		 * This is the structure of AC_*_PARAM registers in 8187B:
		 * - TXOP limit field, bit offset = 16
		 * - ECWmax, bit offset = 12
		 * - ECWmin, bit offset = 8
		 * - AIFS, bit offset = 0
		 */
		rtl818x_iowrite32(priv, rtl8187b_ac_addr[queue],
				  (params->txop << 16) | (cw_max << 12) |
				  (cw_min << 8) | (params->aifs *
				  priv->slot_time + SIFS_TIME));
	} else {
		if (queue != 0)
			return -EINVAL;

		rtl818x_iowrite8(priv, &priv->map->CW_VAL,
				 cw_min | (cw_max << 4));
	}
	return 0;
}


static const struct ieee80211_ops rtl8187_ops = {
	.tx			= rtl8187_tx,
	.start			= rtl8187_start,
	.stop			= rtl8187_stop,
	.add_interface		= rtl8187_add_interface,
	.remove_interface	= rtl8187_remove_interface,
	.config			= rtl8187_config,
	.bss_info_changed	= rtl8187_bss_info_changed,
	.prepare_multicast	= rtl8187_prepare_multicast,
	.configure_filter	= rtl8187_configure_filter,
	.conf_tx		= rtl8187_conf_tx,
	.rfkill_poll		= rtl8187_rfkill_poll,
	.get_tsf		= rtl8187_get_tsf,
};

static void rtl8187_eeprom_register_read(struct eeprom_93cx6 *eeprom)
{
	struct ieee80211_hw *dev = eeprom->data;
	struct rtl8187_priv *priv = dev->priv;
	u8 reg = rtl818x_ioread8(priv, &priv->map->EEPROM_CMD);

	eeprom->reg_data_in = reg & RTL818X_EEPROM_CMD_WRITE;
	eeprom->reg_data_out = reg & RTL818X_EEPROM_CMD_READ;
	eeprom->reg_data_clock = reg & RTL818X_EEPROM_CMD_CK;
	eeprom->reg_chip_select = reg & RTL818X_EEPROM_CMD_CS;
}

static void rtl8187_eeprom_register_write(struct eeprom_93cx6 *eeprom)
{
	struct ieee80211_hw *dev = eeprom->data;
	struct rtl8187_priv *priv = dev->priv;
	u8 reg = RTL818X_EEPROM_CMD_PROGRAM;

	if (eeprom->reg_data_in)
		reg |= RTL818X_EEPROM_CMD_WRITE;
	if (eeprom->reg_data_out)
		reg |= RTL818X_EEPROM_CMD_READ;
	if (eeprom->reg_data_clock)
		reg |= RTL818X_EEPROM_CMD_CK;
	if (eeprom->reg_chip_select)
		reg |= RTL818X_EEPROM_CMD_CS;

	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD, reg);
	udelay(10);
}

static int rtl8187_probe(struct usb_interface *intf,
				   const struct usb_device_id *id)
{
	struct usb_device *udev = interface_to_usbdev(intf);
	struct ieee80211_hw *dev;
	struct rtl8187_priv *priv;
	struct eeprom_93cx6 eeprom;
	struct ieee80211_channel *channel;
	const char *chip_name;
	u16 txpwr, reg;
	u16 product_id = le16_to_cpu(udev->descriptor.idProduct);
	int err, i;
	u8 mac_addr[ETH_ALEN];

	dev = ieee80211_alloc_hw(sizeof(*priv), &rtl8187_ops);
	if (!dev) {
		printk(KERN_ERR "rtl8187: ieee80211 alloc failed\n");
		return -ENOMEM;
	}

	priv = dev->priv;
	priv->is_rtl8187b = (id->driver_info == DEVICE_RTL8187B);

	/* allocate "DMA aware" buffer for register accesses */
	priv->io_dmabuf = kmalloc(sizeof(*priv->io_dmabuf), GFP_KERNEL);
	if (!priv->io_dmabuf) {
		err = -ENOMEM;
		goto err_free_dev;
	}
	mutex_init(&priv->io_mutex);

	SET_IEEE80211_DEV(dev, &intf->dev);
	usb_set_intfdata(intf, dev);
	priv->udev = udev;

	usb_get_dev(udev);

	skb_queue_head_init(&priv->rx_queue);

	BUILD_BUG_ON(sizeof(priv->channels) != sizeof(rtl818x_channels));
	BUILD_BUG_ON(sizeof(priv->rates) != sizeof(rtl818x_rates));

	memcpy(priv->channels, rtl818x_channels, sizeof(rtl818x_channels));
	memcpy(priv->rates, rtl818x_rates, sizeof(rtl818x_rates));
	priv->map = (struct rtl818x_csr *)0xFF00;

	priv->band.band = IEEE80211_BAND_2GHZ;
	priv->band.channels = priv->channels;
	priv->band.n_channels = ARRAY_SIZE(rtl818x_channels);
	priv->band.bitrates = priv->rates;
	priv->band.n_bitrates = ARRAY_SIZE(rtl818x_rates);
	dev->wiphy->bands[IEEE80211_BAND_2GHZ] = &priv->band;


	ieee80211_hw_set(dev, RX_INCLUDES_FCS);
	ieee80211_hw_set(dev, HOST_BROADCAST_PS_BUFFERING);
	ieee80211_hw_set(dev, SIGNAL_DBM);
	/* Initialize rate-control variables */
	dev->max_rates = 1;
	dev->max_rate_tries = RETRY_COUNT;

	eeprom.data = dev;
	eeprom.register_read = rtl8187_eeprom_register_read;
	eeprom.register_write = rtl8187_eeprom_register_write;
	if (rtl818x_ioread32(priv, &priv->map->RX_CONF) & (1 << 6))
		eeprom.width = PCI_EEPROM_WIDTH_93C66;
	else
		eeprom.width = PCI_EEPROM_WIDTH_93C46;

	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD, RTL818X_EEPROM_CMD_CONFIG);
	udelay(10);

	eeprom_93cx6_multiread(&eeprom, RTL8187_EEPROM_MAC_ADDR,
			       (__le16 __force *)mac_addr, 3);
	if (!is_valid_ether_addr(mac_addr)) {
		printk(KERN_WARNING "rtl8187: Invalid hwaddr! Using randomly "
		       "generated MAC address\n");
		eth_random_addr(mac_addr);
	}
	SET_IEEE80211_PERM_ADDR(dev, mac_addr);

	channel = priv->channels;
	for (i = 0; i < 3; i++) {
		eeprom_93cx6_read(&eeprom, RTL8187_EEPROM_TXPWR_CHAN_1 + i,
				  &txpwr);
		(*channel++).hw_value = txpwr & 0xFF;
		(*channel++).hw_value = txpwr >> 8;
	}
	for (i = 0; i < 2; i++) {
		eeprom_93cx6_read(&eeprom, RTL8187_EEPROM_TXPWR_CHAN_4 + i,
				  &txpwr);
		(*channel++).hw_value = txpwr & 0xFF;
		(*channel++).hw_value = txpwr >> 8;
	}

	eeprom_93cx6_read(&eeprom, RTL8187_EEPROM_TXPWR_BASE,
			  &priv->txpwr_base);

	reg = rtl818x_ioread8(priv, &priv->map->PGSELECT) & ~1;
	rtl818x_iowrite8(priv, &priv->map->PGSELECT, reg | 1);
	/* 0 means asic B-cut, we should use SW 3 wire
	 * bit-by-bit banging for radio. 1 means we can use
	 * USB specific request to write radio registers */
	priv->asic_rev = rtl818x_ioread8(priv, (u8 *)0xFFFE) & 0x3;
	rtl818x_iowrite8(priv, &priv->map->PGSELECT, reg);
	rtl818x_iowrite8(priv, &priv->map->EEPROM_CMD, RTL818X_EEPROM_CMD_NORMAL);

	if (!priv->is_rtl8187b) {
		u32 reg32;
		reg32 = rtl818x_ioread32(priv, &priv->map->TX_CONF);
		reg32 &= RTL818X_TX_CONF_HWVER_MASK;
		switch (reg32) {
		case RTL818X_TX_CONF_R8187vD_B:
			/* Some RTL8187B devices have a USB ID of 0x8187
			 * detect them here */
			chip_name = "RTL8187BvB(early)";
			priv->is_rtl8187b = 1;
			priv->hw_rev = RTL8187BvB;
			break;
		case RTL818X_TX_CONF_R8187vD:
			chip_name = "RTL8187vD";
			break;
		default:
			chip_name = "RTL8187vB (default)";
		}
       } else {
		/*
		 * Force USB request to write radio registers for 8187B, Realtek
		 * only uses it in their sources
		 */
		/*if (priv->asic_rev == 0) {
			printk(KERN_WARNING "rtl8187: Forcing use of USB "
			       "requests to write to radio registers\n");
			priv->asic_rev = 1;
		}*/
		switch (rtl818x_ioread8(priv, (u8 *)0xFFE1)) {
		case RTL818X_R8187B_B:
			chip_name = "RTL8187BvB";
			priv->hw_rev = RTL8187BvB;
			break;
		case RTL818X_R8187B_D:
			chip_name = "RTL8187BvD";
			priv->hw_rev = RTL8187BvD;
			break;
		case RTL818X_R8187B_E:
			chip_name = "RTL8187BvE";
			priv->hw_rev = RTL8187BvE;
			break;
		default:
			chip_name = "RTL8187BvB (default)";
			priv->hw_rev = RTL8187BvB;
		}
	}

	if (!priv->is_rtl8187b) {
		for (i = 0; i < 2; i++) {
			eeprom_93cx6_read(&eeprom,
					  RTL8187_EEPROM_TXPWR_CHAN_6 + i,
					  &txpwr);
			(*channel++).hw_value = txpwr & 0xFF;
			(*channel++).hw_value = txpwr >> 8;
		}
	} else {
		eeprom_93cx6_read(&eeprom, RTL8187_EEPROM_TXPWR_CHAN_6,
				  &txpwr);
		(*channel++).hw_value = txpwr & 0xFF;

		eeprom_93cx6_read(&eeprom, 0x0A, &txpwr);
		(*channel++).hw_value = txpwr & 0xFF;

		eeprom_93cx6_read(&eeprom, 0x1C, &txpwr);
		(*channel++).hw_value = txpwr & 0xFF;
		(*channel++).hw_value = txpwr >> 8;
	}
	/* Handle the differing rfkill GPIO bit in different models */
	priv->rfkill_mask = RFKILL_MASK_8187_89_97;
	if (product_id == 0x8197 || product_id == 0x8198) {
		eeprom_93cx6_read(&eeprom, RTL8187_EEPROM_SELECT_GPIO, &reg);
		if (reg & 0xFF00)
			priv->rfkill_mask = RFKILL_MASK_8198;
	}
	dev->vif_data_size = sizeof(struct rtl8187_vif);
	dev->wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION) |
				      BIT(NL80211_IFTYPE_ADHOC) ;

	if ((id->driver_info == DEVICE_RTL8187) && priv->is_rtl8187b)
		printk(KERN_INFO "rtl8187: inconsistency between id with OEM"
		       " info!\n");

	priv->rf = rtl8187_detect_rf(dev);
	dev->extra_tx_headroom = (!priv->is_rtl8187b) ?
				  sizeof(struct rtl8187_tx_hdr) :
				  sizeof(struct rtl8187b_tx_hdr);
	if (!priv->is_rtl8187b)
		dev->queues = 1;
	else
		dev->queues = 4;

	err = ieee80211_register_hw(dev);
	if (err) {
		printk(KERN_ERR "rtl8187: Cannot register device\n");
		goto err_free_dmabuf;
	}
	mutex_init(&priv->conf_mutex);
	skb_queue_head_init(&priv->b_tx_status.queue);

	wiphy_info(dev->wiphy, "hwaddr %pM, %s V%d + %s, rfkill mask %d\n",
		   mac_addr, chip_name, priv->asic_rev, priv->rf->name,
		   priv->rfkill_mask);

#ifdef CPTCFG_RTL8187_LEDS
	eeprom_93cx6_read(&eeprom, 0x3F, &reg);
	reg &= 0xFF;
	rtl8187_leds_init(dev, reg);
#endif
	rtl8187_rfkill_init(dev);

	return 0;

 err_free_dmabuf:
	kfree(priv->io_dmabuf);
	usb_set_intfdata(intf, NULL);
	usb_put_dev(udev);
 err_free_dev:
	ieee80211_free_hw(dev);
	return err;
}

static void rtl8187_disconnect(struct usb_interface *intf)
{
	struct ieee80211_hw *dev = usb_get_intfdata(intf);
	struct rtl8187_priv *priv;

	if (!dev)
		return;

#ifdef CPTCFG_RTL8187_LEDS
	rtl8187_leds_exit(dev);
#endif
	rtl8187_rfkill_exit(dev);
	ieee80211_unregister_hw(dev);

	priv = dev->priv;
	usb_reset_device(priv->udev);
	usb_put_dev(interface_to_usbdev(intf));
	kfree(priv->io_dmabuf);
	ieee80211_free_hw(dev);
}

static struct usb_driver rtl8187_driver = {
	.name		= KBUILD_MODNAME,
	.id_table	= rtl8187_table,
	.probe		= rtl8187_probe,
	.disconnect	= rtl8187_disconnect,
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0))
	.disable_hub_initiated_lpm = 1,
#endif
};

module_usb_driver(rtl8187_driver);