drivers/net/ieee802154/atusb.c - kernel/bruno - Git at Google

 /*
  * atusb.c - Driver for the ATUSB IEEE 802.15.4 dongle
  *
  * Written 2013 by Werner Almesberger <werner@almesberger.net>
  *
  * 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, version 2
  *
  * Based on at86rf230.c and spi_atusb.c.
  * at86rf230.c is
  * Copyright (C) 2009 Siemens AG
  * Written by: Dmitry Eremin-Solenikov <dmitry.baryshkov@siemens.com>
  *
  * spi_atusb.c is
  * Copyright (c) 2011 Richard Sharpe <realrichardsharpe@gmail.com>
  * Copyright (c) 2011 Stefan Schmidt <stefan@datenfreihafen.org>
  * Copyright (c) 2011 Werner Almesberger <werner@almesberger.net>
  *
  * USB initialization is
  * Copyright (c) 2013 Alexander Aring <alex.aring@gmail.com>
  */

 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/jiffies.h>
 #include <linux/usb.h>
 #include <linux/skbuff.h>

 #include <net/cfg802154.h>
 #include <net/mac802154.h>

 #include "at86rf230.h"
 #include "atusb.h"

 #define ATUSB_JEDEC_ATMEL	0x1f	/* JEDEC manufacturer ID */

 #define ATUSB_NUM_RX_URBS	4	/* allow for a bit of local latency */
 #define ATUSB_ALLOC_DELAY_MS	100	/* delay after failed allocation */
 #define ATUSB_TX_TIMEOUT_MS	200	/* on the air timeout */

 struct atusb {
 	struct ieee802154_hw *hw;
 	struct usb_device *usb_dev;
 	int shutdown;			/* non-zero if shutting down */
 	int err;			/* set by first error */

 	/* RX variables */
 	struct delayed_work work;	/* memory allocations */
 	struct usb_anchor idle_urbs;	/* URBs waiting to be submitted */
 	struct usb_anchor rx_urbs;	/* URBs waiting for reception */

 	/* TX variables */
 	struct usb_ctrlrequest tx_dr;
 	struct urb *tx_urb;
 	struct sk_buff *tx_skb;
 	uint8_t tx_ack_seq;		/* current TX ACK sequence number */
 };

 /* ----- USB commands without data ----------------------------------------- */

 /* To reduce the number of error checks in the code, we record the first error
  * in atusb->err and reject all subsequent requests until the error is cleared.
  */

 static int atusb_control_msg(struct atusb *atusb, unsigned int pipe,
 			     __u8 request, __u8 requesttype,
 			     __u16 value, __u16 index,
 			     void *data, __u16 size, int timeout)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
 	int ret;

 	if (atusb->err)
 		return atusb->err;

 	ret = usb_control_msg(usb_dev, pipe, request, requesttype,
 			      value, index, data, size, timeout);
 	if (ret < 0) {
 		atusb->err = ret;
 		dev_err(&usb_dev->dev,
 			"atusb_control_msg: req 0x%02x val 0x%x idx 0x%x, error %d\n",
 			request, value, index, ret);
 	}
 	return ret;
 }

 static int atusb_command(struct atusb *atusb, uint8_t cmd, uint8_t arg)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;

 	dev_dbg(&usb_dev->dev, "atusb_command: cmd = 0x%x\n", cmd);
 	return atusb_control_msg(atusb, usb_sndctrlpipe(usb_dev, 0),
 				 cmd, ATUSB_REQ_TO_DEV, arg, 0, NULL, 0, 1000);
 }

 static int atusb_write_reg(struct atusb *atusb, uint8_t reg, uint8_t value)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;

 	dev_dbg(&usb_dev->dev, "atusb_write_reg: 0x%02x <- 0x%02x\n",
 		reg, value);
 	return atusb_control_msg(atusb, usb_sndctrlpipe(usb_dev, 0),
 				 ATUSB_REG_WRITE, ATUSB_REQ_TO_DEV,
 				 value, reg, NULL, 0, 1000);
 }

 static int atusb_read_reg(struct atusb *atusb, uint8_t reg)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
 	int ret;
 	uint8_t value;

 	dev_dbg(&usb_dev->dev, "atusb: reg = 0x%x\n", reg);
 	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
 				ATUSB_REG_READ, ATUSB_REQ_FROM_DEV,
 				0, reg, &value, 1, 1000);
 	return ret >= 0 ? value : ret;
 }

 static int atusb_write_subreg(struct atusb *atusb, uint8_t reg, uint8_t mask,
 			      uint8_t shift, uint8_t value)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
 	uint8_t orig, tmp;
 	int ret = 0;

 	dev_dbg(&usb_dev->dev, "atusb_write_subreg: 0x%02x <- 0x%02x\n",
 		reg, value);

 	orig = atusb_read_reg(atusb, reg);

 	/* Write the value only into that part of the register which is allowed
 	 * by the mask. All other bits stay as before.
 	 */
 	tmp = orig & ~mask;
 	tmp |= (value << shift) & mask;

 	if (tmp != orig)
 		ret = atusb_write_reg(atusb, reg, tmp);

 	return ret;
 }

 static int atusb_get_and_clear_error(struct atusb *atusb)
 {
 	int err = atusb->err;

 	atusb->err = 0;
 	return err;
 }

 /* ----- skb allocation ---------------------------------------------------- */

 #define MAX_PSDU	127
 #define MAX_RX_XFER	(1 + MAX_PSDU + 2 + 1)	/* PHR+PSDU+CRC+LQI */

 #define SKB_ATUSB(skb)	(*(struct atusb **)(skb)->cb)

 static void atusb_in(struct urb *urb);

 static int atusb_submit_rx_urb(struct atusb *atusb, struct urb *urb)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
 	struct sk_buff *skb = urb->context;
 	int ret;

 	if (!skb) {
 		skb = alloc_skb(MAX_RX_XFER, GFP_KERNEL);
 		if (!skb) {
 			dev_warn_ratelimited(&usb_dev->dev,
 					     "atusb_in: can't allocate skb\n");
 			return -ENOMEM;
 		}
 		skb_put(skb, MAX_RX_XFER);
 		SKB_ATUSB(skb) = atusb;
 	}

 	usb_fill_bulk_urb(urb, usb_dev, usb_rcvbulkpipe(usb_dev, 1),
 			  skb->data, MAX_RX_XFER, atusb_in, skb);
 	usb_anchor_urb(urb, &atusb->rx_urbs);

 	ret = usb_submit_urb(urb, GFP_KERNEL);
 	if (ret) {
 		usb_unanchor_urb(urb);
 		kfree_skb(skb);
 		urb->context = NULL;
 	}
 	return ret;
 }

 static void atusb_work_urbs(struct work_struct *work)
 {
 	struct atusb *atusb =
 	    container_of(to_delayed_work(work), struct atusb, work);
 	struct usb_device *usb_dev = atusb->usb_dev;
 	struct urb *urb;
 	int ret;

 	if (atusb->shutdown)
 		return;

 	do {
 		urb = usb_get_from_anchor(&atusb->idle_urbs);
 		if (!urb)
 			return;
 		ret = atusb_submit_rx_urb(atusb, urb);
 	} while (!ret);

 	usb_anchor_urb(urb, &atusb->idle_urbs);
 	dev_warn_ratelimited(&usb_dev->dev,
 			     "atusb_in: can't allocate/submit URB (%d)\n", ret);
 	schedule_delayed_work(&atusb->work,
 			      msecs_to_jiffies(ATUSB_ALLOC_DELAY_MS) + 1);
 }

 /* ----- Asynchronous USB -------------------------------------------------- */

 static void atusb_tx_done(struct atusb *atusb, uint8_t seq)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
 	uint8_t expect = atusb->tx_ack_seq;

 	dev_dbg(&usb_dev->dev, "atusb_tx_done (0x%02x/0x%02x)\n", seq, expect);
 	if (seq == expect) {
 		/* TODO check for ifs handling in firmware */
 		ieee802154_xmit_complete(atusb->hw, atusb->tx_skb, false);
 	} else {
 		/* TODO I experience this case when atusb has a tx complete
 		 * irq before probing, we should fix the firmware it's an
 		 * unlikely case now that seq == expect is then true, but can
 		 * happen and fail with a tx_skb = NULL;
 		 */
 		ieee802154_wake_queue(atusb->hw);
 		if (atusb->tx_skb)
 			dev_kfree_skb_irq(atusb->tx_skb);
 	}
 }

 static void atusb_in_good(struct urb *urb)
 {
 	struct usb_device *usb_dev = urb->dev;
 	struct sk_buff *skb = urb->context;
 	struct atusb *atusb = SKB_ATUSB(skb);
 	uint8_t len, lqi;

 	if (!urb->actual_length) {
 		dev_dbg(&usb_dev->dev, "atusb_in: zero-sized URB ?\n");
 		return;
 	}

 	len = *skb->data;

 	if (urb->actual_length == 1) {
 		atusb_tx_done(atusb, len);
 		return;
 	}

 	if (len + 1 > urb->actual_length - 1) {
 		dev_dbg(&usb_dev->dev, "atusb_in: frame len %d+1 > URB %u-1\n",
 			len, urb->actual_length);
 		return;
 	}

 	if (!ieee802154_is_valid_psdu_len(len)) {
 		dev_dbg(&usb_dev->dev, "atusb_in: frame corrupted\n");
 		return;
 	}

 	lqi = skb->data[len + 1];
 	dev_dbg(&usb_dev->dev, "atusb_in: rx len %d lqi 0x%02x\n", len, lqi);
 	skb_pull(skb, 1);	/* remove PHR */
 	skb_trim(skb, len);	/* get payload only */
 	ieee802154_rx_irqsafe(atusb->hw, skb, lqi);
 	urb->context = NULL;	/* skb is gone */
 }

 static void atusb_in(struct urb *urb)
 {
 	struct usb_device *usb_dev = urb->dev;
 	struct sk_buff *skb = urb->context;
 	struct atusb *atusb = SKB_ATUSB(skb);

 	dev_dbg(&usb_dev->dev, "atusb_in: status %d len %d\n",
 		urb->status, urb->actual_length);
 	if (urb->status) {
 		if (urb->status == -ENOENT) { /* being killed */
 			kfree_skb(skb);
 			urb->context = NULL;
 			return;
 		}
 		dev_dbg(&usb_dev->dev, "atusb_in: URB error %d\n", urb->status);
 	} else {
 		atusb_in_good(urb);
 	}

 	usb_anchor_urb(urb, &atusb->idle_urbs);
 	if (!atusb->shutdown)
 		schedule_delayed_work(&atusb->work, 0);
 }

 /* ----- URB allocation/deallocation --------------------------------------- */

 static void atusb_free_urbs(struct atusb *atusb)
 {
 	struct urb *urb;

 	while (1) {
 		urb = usb_get_from_anchor(&atusb->idle_urbs);
 		if (!urb)
 			break;
 		if (urb->context)
 			kfree_skb(urb->context);
 		usb_free_urb(urb);
 	}
 }

 static int atusb_alloc_urbs(struct atusb *atusb, int n)
 {
 	struct urb *urb;

 	while (n) {
 		urb = usb_alloc_urb(0, GFP_KERNEL);
 		if (!urb) {
 			atusb_free_urbs(atusb);
 			return -ENOMEM;
 		}
 		usb_anchor_urb(urb, &atusb->idle_urbs);
 		n--;
 	}
 	return 0;
 }

 /* ----- IEEE 802.15.4 interface operations -------------------------------- */

 static void atusb_xmit_complete(struct urb *urb)
 {
 	dev_dbg(&urb->dev->dev, "atusb_xmit urb completed");
 }

 static int atusb_xmit(struct ieee802154_hw *hw, struct sk_buff *skb)
 {
 	struct atusb *atusb = hw->priv;
 	struct usb_device *usb_dev = atusb->usb_dev;
 	int ret;

 	dev_dbg(&usb_dev->dev, "atusb_xmit (%d)\n", skb->len);
 	atusb->tx_skb = skb;
 	atusb->tx_ack_seq++;
 	atusb->tx_dr.wIndex = cpu_to_le16(atusb->tx_ack_seq);
 	atusb->tx_dr.wLength = cpu_to_le16(skb->len);

 	usb_fill_control_urb(atusb->tx_urb, usb_dev,
 			     usb_sndctrlpipe(usb_dev, 0),
 			     (unsigned char *)&atusb->tx_dr, skb->data,
 			     skb->len, atusb_xmit_complete, NULL);
 	ret = usb_submit_urb(atusb->tx_urb, GFP_ATOMIC);
 	dev_dbg(&usb_dev->dev, "atusb_xmit done (%d)\n", ret);
 	return ret;
 }

 static int atusb_channel(struct ieee802154_hw *hw, u8 page, u8 channel)
 {
 	struct atusb *atusb = hw->priv;
 	int ret;

 	/* This implicitly sets the CCA (Clear Channel Assessment) mode to 0,
 	 * "Mode 3a, Carrier sense OR energy above threshold".
 	 * We should probably make this configurable. @@@
 	 */
 	ret = atusb_write_reg(atusb, RG_PHY_CC_CCA, channel);
 	if (ret < 0)
 		return ret;
 	msleep(1);	/* @@@ ugly synchronization */
 	return 0;
 }

 static int atusb_ed(struct ieee802154_hw *hw, u8 *level)
 {
 	BUG_ON(!level);
 	*level = 0xbe;
 	return 0;
 }

 static int atusb_set_hw_addr_filt(struct ieee802154_hw *hw,
 				  struct ieee802154_hw_addr_filt *filt,
 				  unsigned long changed)
 {
 	struct atusb *atusb = hw->priv;
 	struct device *dev = &atusb->usb_dev->dev;

 	if (changed & IEEE802154_AFILT_SADDR_CHANGED) {
 		u16 addr = le16_to_cpu(filt->short_addr);

 		dev_vdbg(dev, "atusb_set_hw_addr_filt called for saddr\n");
 		atusb_write_reg(atusb, RG_SHORT_ADDR_0, addr);
 		atusb_write_reg(atusb, RG_SHORT_ADDR_1, addr >> 8);
 	}

 	if (changed & IEEE802154_AFILT_PANID_CHANGED) {
 		u16 pan = le16_to_cpu(filt->pan_id);

 		dev_vdbg(dev, "atusb_set_hw_addr_filt called for pan id\n");
 		atusb_write_reg(atusb, RG_PAN_ID_0, pan);
 		atusb_write_reg(atusb, RG_PAN_ID_1, pan >> 8);
 	}

 	if (changed & IEEE802154_AFILT_IEEEADDR_CHANGED) {
 		u8 i, addr[IEEE802154_EXTENDED_ADDR_LEN];

 		memcpy(addr, &filt->ieee_addr, IEEE802154_EXTENDED_ADDR_LEN);
 		dev_vdbg(dev, "atusb_set_hw_addr_filt called for IEEE addr\n");
 		for (i = 0; i < 8; i++)
 			atusb_write_reg(atusb, RG_IEEE_ADDR_0 + i, addr[i]);
 	}

 	if (changed & IEEE802154_AFILT_PANC_CHANGED) {
 		dev_vdbg(dev,
 			 "atusb_set_hw_addr_filt called for panc change\n");
 		if (filt->pan_coord)
 			atusb_write_subreg(atusb, SR_AACK_I_AM_COORD, 1);
 		else
 			atusb_write_subreg(atusb, SR_AACK_I_AM_COORD, 0);
 	}

 	return atusb_get_and_clear_error(atusb);
 }

 static int atusb_start(struct ieee802154_hw *hw)
 {
 	struct atusb *atusb = hw->priv;
 	struct usb_device *usb_dev = atusb->usb_dev;
 	int ret;

 	dev_dbg(&usb_dev->dev, "atusb_start\n");
 	schedule_delayed_work(&atusb->work, 0);
 	atusb_command(atusb, ATUSB_RX_MODE, 1);
 	ret = atusb_get_and_clear_error(atusb);
 	if (ret < 0)
 		usb_kill_anchored_urbs(&atusb->idle_urbs);
 	return ret;
 }

 static void atusb_stop(struct ieee802154_hw *hw)
 {
 	struct atusb *atusb = hw->priv;
 	struct usb_device *usb_dev = atusb->usb_dev;

 	dev_dbg(&usb_dev->dev, "atusb_stop\n");
 	usb_kill_anchored_urbs(&atusb->idle_urbs);
 	atusb_command(atusb, ATUSB_RX_MODE, 0);
 	atusb_get_and_clear_error(atusb);
 }

 #define ATUSB_MAX_TX_POWERS 0xF
 static const s32 atusb_powers[ATUSB_MAX_TX_POWERS + 1] = {
 	300, 280, 230, 180, 130, 70, 0, -100, -200, -300, -400, -500, -700,
 	-900, -1200, -1700,
 };

 static int
 atusb_set_txpower(struct ieee802154_hw *hw, s32 mbm)
 {
 	struct atusb *atusb = hw->priv;
 	u32 i;

 	for (i = 0; i < hw->phy->supported.tx_powers_size; i++) {
 		if (hw->phy->supported.tx_powers[i] == mbm)
 			return atusb_write_subreg(atusb, SR_TX_PWR_23X, i);
 	}

 	return -EINVAL;
 }

 static int
 atusb_set_promiscuous_mode(struct ieee802154_hw *hw, const bool on)
 {
 	struct atusb *atusb = hw->priv;
 	int ret;

 	if (on) {
 		ret = atusb_write_subreg(atusb, SR_AACK_DIS_ACK, 1);
 		if (ret < 0)
 			return ret;

 		ret = atusb_write_subreg(atusb, SR_AACK_PROM_MODE, 1);
 		if (ret < 0)
 			return ret;
 	} else {
 		ret = atusb_write_subreg(atusb, SR_AACK_PROM_MODE, 0);
 		if (ret < 0)
 			return ret;

 		ret = atusb_write_subreg(atusb, SR_AACK_DIS_ACK, 0);
 		if (ret < 0)
 			return ret;
 	}

 	return 0;
 }

 static struct ieee802154_ops atusb_ops = {
 	.owner			= THIS_MODULE,
 	.xmit_async		= atusb_xmit,
 	.ed			= atusb_ed,
 	.set_channel		= atusb_channel,
 	.start			= atusb_start,
 	.stop			= atusb_stop,
 	.set_hw_addr_filt	= atusb_set_hw_addr_filt,
 	.set_txpower		= atusb_set_txpower,
 	.set_promiscuous_mode	= atusb_set_promiscuous_mode,
 };

 /* ----- Firmware and chip version information ----------------------------- */

 static int atusb_get_and_show_revision(struct atusb *atusb)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
 	unsigned char buffer[3];
 	int ret;

 	/* Get a couple of the ATMega Firmware values */
 	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
 				ATUSB_ID, ATUSB_REQ_FROM_DEV, 0, 0,
 				buffer, 3, 1000);
 	if (ret >= 0)
 		dev_info(&usb_dev->dev,
 			 "Firmware: major: %u, minor: %u, hardware type: %u\n",
 			 buffer[0], buffer[1], buffer[2]);
 	if (buffer[0] == 0 && buffer[1] < 2) {
 		dev_info(&usb_dev->dev,
 			 "Firmware version (%u.%u) is predates our first public release.",
 			 buffer[0], buffer[1]);
 		dev_info(&usb_dev->dev, "Please update to version 0.2 or newer");
 	}

 	return ret;
 }

 static int atusb_get_and_show_build(struct atusb *atusb)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
 	char build[ATUSB_BUILD_SIZE + 1];
 	int ret;

 	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
 				ATUSB_BUILD, ATUSB_REQ_FROM_DEV, 0, 0,
 				build, ATUSB_BUILD_SIZE, 1000);
 	if (ret >= 0) {
 		build[ret] = 0;
 		dev_info(&usb_dev->dev, "Firmware: build %s\n", build);
 	}

 	return ret;
 }

 static int atusb_get_and_show_chip(struct atusb *atusb)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
 	uint8_t man_id_0, man_id_1, part_num, version_num;
 	const char *chip;

 	man_id_0 = atusb_read_reg(atusb, RG_MAN_ID_0);
 	man_id_1 = atusb_read_reg(atusb, RG_MAN_ID_1);
 	part_num = atusb_read_reg(atusb, RG_PART_NUM);
 	version_num = atusb_read_reg(atusb, RG_VERSION_NUM);

 	if (atusb->err)
 		return atusb->err;

 	if ((man_id_1 << 8 | man_id_0) != ATUSB_JEDEC_ATMEL) {
 		dev_err(&usb_dev->dev,
 			"non-Atmel transceiver xxxx%02x%02x\n",
 			man_id_1, man_id_0);
 		goto fail;
 	}

 	switch (part_num) {
 	case 2:
 		chip = "AT86RF230";
 		break;
 	case 3:
 		chip = "AT86RF231";
 		break;
 	default:
 		dev_err(&usb_dev->dev,
 			"unexpected transceiver, part 0x%02x version 0x%02x\n",
 			part_num, version_num);
 		goto fail;
 	}

 	dev_info(&usb_dev->dev, "ATUSB: %s version %d\n", chip, version_num);

 	return 0;

 fail:
 	atusb->err = -ENODEV;
 	return -ENODEV;
 }

 /* ----- Setup ------------------------------------------------------------- */

 static int atusb_probe(struct usb_interface *interface,
 		       const struct usb_device_id *id)
 {
 	struct usb_device *usb_dev = interface_to_usbdev(interface);
 	struct ieee802154_hw *hw;
 	struct atusb *atusb = NULL;
 	int ret = -ENOMEM;

 	hw = ieee802154_alloc_hw(sizeof(struct atusb), &atusb_ops);
 	if (!hw)
 		return -ENOMEM;

 	atusb = hw->priv;
 	atusb->hw = hw;
 	atusb->usb_dev = usb_get_dev(usb_dev);
 	usb_set_intfdata(interface, atusb);

 	atusb->shutdown = 0;
 	atusb->err = 0;
 	INIT_DELAYED_WORK(&atusb->work, atusb_work_urbs);
 	init_usb_anchor(&atusb->idle_urbs);
 	init_usb_anchor(&atusb->rx_urbs);

 	if (atusb_alloc_urbs(atusb, ATUSB_NUM_RX_URBS))
 		goto fail;

 	atusb->tx_dr.bRequestType = ATUSB_REQ_TO_DEV;
 	atusb->tx_dr.bRequest = ATUSB_TX;
 	atusb->tx_dr.wValue = cpu_to_le16(0);

 	atusb->tx_urb = usb_alloc_urb(0, GFP_ATOMIC);
 	if (!atusb->tx_urb)
 		goto fail;

 	hw->parent = &usb_dev->dev;
 	hw->flags = IEEE802154_HW_TX_OMIT_CKSUM | IEEE802154_HW_AFILT |
 		    IEEE802154_HW_PROMISCUOUS;

 	hw->phy->flags = WPAN_PHY_FLAG_TXPOWER;

 	hw->phy->current_page = 0;
 	hw->phy->current_channel = 11;	/* reset default */
 	hw->phy->supported.channels[0] = 0x7FFF800;
 	hw->phy->supported.tx_powers = atusb_powers;
 	hw->phy->supported.tx_powers_size = ARRAY_SIZE(atusb_powers);
 	hw->phy->transmit_power = hw->phy->supported.tx_powers[0];
 	ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);

 	atusb_command(atusb, ATUSB_RF_RESET, 0);
 	atusb_get_and_show_chip(atusb);
 	atusb_get_and_show_revision(atusb);
 	atusb_get_and_show_build(atusb);
 	ret = atusb_get_and_clear_error(atusb);
 	if (ret) {
 		dev_err(&atusb->usb_dev->dev,
 			"%s: initialization failed, error = %d\n",
 			__func__, ret);
 		goto fail;
 	}

 	ret = ieee802154_register_hw(hw);
 	if (ret)
 		goto fail;

 	/* If we just powered on, we're now in P_ON and need to enter TRX_OFF
 	 * explicitly. Any resets after that will send us straight to TRX_OFF,
 	 * making the command below redundant.
 	 */
 	atusb_write_reg(atusb, RG_TRX_STATE, STATE_FORCE_TRX_OFF);
 	msleep(1);	/* reset => TRX_OFF, tTR13 = 37 us */

 #if 0
 	/* Calculating the maximum time available to empty the frame buffer
 	 * on reception:
 	 *
 	 * According to [1], the inter-frame gap is
 	 * R * 20 * 16 us + 128 us
 	 * where R is a random number from 0 to 7. Furthermore, we have 20 bit
 	 * times (80 us at 250 kbps) of SHR of the next frame before the
 	 * transceiver begins storing data in the frame buffer.
 	 *
 	 * This yields a minimum time of 208 us between the last data of a
 	 * frame and the first data of the next frame. This time is further
 	 * reduced by interrupt latency in the atusb firmware.
 	 *
 	 * atusb currently needs about 500 us to retrieve a maximum-sized
 	 * frame. We therefore have to allow reception of a new frame to begin
 	 * while we retrieve the previous frame.
 	 *
 	 * [1] "JN-AN-1035 Calculating data rates in an IEEE 802.15.4-based
 	 *      network", Jennic 2006.
 	 *     http://www.jennic.com/download_file.php?supportFile=JN-AN-1035%20Calculating%20802-15-4%20Data%20Rates-1v0.pdf
 	 */

 	atusb_write_subreg(atusb, SR_RX_SAFE_MODE, 1);
 #endif
 	atusb_write_reg(atusb, RG_IRQ_MASK, 0xff);

 	ret = atusb_get_and_clear_error(atusb);
 	if (!ret)
 		return 0;

 	dev_err(&atusb->usb_dev->dev,
 		"%s: setup failed, error = %d\n",
 		__func__, ret);

 	ieee802154_unregister_hw(hw);
 fail:
 	atusb_free_urbs(atusb);
 	usb_kill_urb(atusb->tx_urb);
 	usb_free_urb(atusb->tx_urb);
 	usb_put_dev(usb_dev);
 	ieee802154_free_hw(hw);
 	return ret;
 }

 static void atusb_disconnect(struct usb_interface *interface)
 {
 	struct atusb *atusb = usb_get_intfdata(interface);

 	dev_dbg(&atusb->usb_dev->dev, "atusb_disconnect\n");

 	atusb->shutdown = 1;
 	cancel_delayed_work_sync(&atusb->work);

 	usb_kill_anchored_urbs(&atusb->rx_urbs);
 	atusb_free_urbs(atusb);
 	usb_kill_urb(atusb->tx_urb);
 	usb_free_urb(atusb->tx_urb);

 	ieee802154_unregister_hw(atusb->hw);

 	ieee802154_free_hw(atusb->hw);

 	usb_set_intfdata(interface, NULL);
 	usb_put_dev(atusb->usb_dev);

 	pr_debug("atusb_disconnect done\n");
 }

 /* The devices we work with */
 static const struct usb_device_id atusb_device_table[] = {
 	{
 		.match_flags		= USB_DEVICE_ID_MATCH_DEVICE |
 					  USB_DEVICE_ID_MATCH_INT_INFO,
 		.idVendor		= ATUSB_VENDOR_ID,
 		.idProduct		= ATUSB_PRODUCT_ID,
 		.bInterfaceClass	= USB_CLASS_VENDOR_SPEC
 	},
 	/* end with null element */
 	{}
 };
 MODULE_DEVICE_TABLE(usb, atusb_device_table);

 static struct usb_driver atusb_driver = {
 	.name		= "atusb",
 	.probe		= atusb_probe,
 	.disconnect	= atusb_disconnect,
 	.id_table	= atusb_device_table,
 };
 module_usb_driver(atusb_driver);

 MODULE_AUTHOR("Alexander Aring <alex.aring@gmail.com>");
 MODULE_AUTHOR("Richard Sharpe <realrichardsharpe@gmail.com>");
 MODULE_AUTHOR("Stefan Schmidt <stefan@datenfreihafen.org>");
 MODULE_AUTHOR("Werner Almesberger <werner@almesberger.net>");
 MODULE_DESCRIPTION("ATUSB IEEE 802.15.4 Driver");
 MODULE_LICENSE("GPL");
	/*
	* atusb.c - Driver for the ATUSB IEEE 802.15.4 dongle
	*
	* Written 2013 by Werner Almesberger <werner@almesberger.net>
	*
	* 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, version 2
	*
	* Based on at86rf230.c and spi_atusb.c.
	* at86rf230.c is
	* Copyright (C) 2009 Siemens AG
	* Written by: Dmitry Eremin-Solenikov <dmitry.baryshkov@siemens.com>
	*
	* spi_atusb.c is
	* Copyright (c) 2011 Richard Sharpe <realrichardsharpe@gmail.com>
	* Copyright (c) 2011 Stefan Schmidt <stefan@datenfreihafen.org>
	* Copyright (c) 2011 Werner Almesberger <werner@almesberger.net>
	*
	* USB initialization is
	* Copyright (c) 2013 Alexander Aring <alex.aring@gmail.com>
	*/

	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/jiffies.h>
	#include <linux/usb.h>
	#include <linux/skbuff.h>

	#include <net/cfg802154.h>
	#include <net/mac802154.h>

	#include "at86rf230.h"
	#include "atusb.h"

	#define ATUSB_JEDEC_ATMEL 0x1f /* JEDEC manufacturer ID */

	#define ATUSB_NUM_RX_URBS 4 /* allow for a bit of local latency */
	#define ATUSB_ALLOC_DELAY_MS 100 /* delay after failed allocation */
	#define ATUSB_TX_TIMEOUT_MS 200 /* on the air timeout */

	struct atusb {
	struct ieee802154_hw *hw;
	struct usb_device *usb_dev;
	int shutdown; /* non-zero if shutting down */
	int err; /* set by first error */

	/* RX variables */
	struct delayed_work work; /* memory allocations */
	struct usb_anchor idle_urbs; /* URBs waiting to be submitted */
	struct usb_anchor rx_urbs; /* URBs waiting for reception */

	/* TX variables */
	struct usb_ctrlrequest tx_dr;
	struct urb *tx_urb;
	struct sk_buff *tx_skb;
	uint8_t tx_ack_seq; /* current TX ACK sequence number */
	};

	/* ----- USB commands without data ----------------------------------------- */

	/* To reduce the number of error checks in the code, we record the first error
	* in atusb->err and reject all subsequent requests until the error is cleared.
	*/

	static int atusb_control_msg(struct atusb *atusb, unsigned int pipe,
	__u8 request, __u8 requesttype,
	__u16 value, __u16 index,
	void *data, __u16 size, int timeout)
	{
	struct usb_device *usb_dev = atusb->usb_dev;
	int ret;

	if (atusb->err)
	return atusb->err;

	ret = usb_control_msg(usb_dev, pipe, request, requesttype,
	value, index, data, size, timeout);
	if (ret < 0) {
	atusb->err = ret;
	dev_err(&usb_dev->dev,
	"atusb_control_msg: req 0x%02x val 0x%x idx 0x%x, error %d\n",
	request, value, index, ret);
	}
	return ret;
	}

	static int atusb_command(struct atusb *atusb, uint8_t cmd, uint8_t arg)
	{
	struct usb_device *usb_dev = atusb->usb_dev;

	dev_dbg(&usb_dev->dev, "atusb_command: cmd = 0x%x\n", cmd);
	return atusb_control_msg(atusb, usb_sndctrlpipe(usb_dev, 0),
	cmd, ATUSB_REQ_TO_DEV, arg, 0, NULL, 0, 1000);
	}

	static int atusb_write_reg(struct atusb *atusb, uint8_t reg, uint8_t value)
	{
	struct usb_device *usb_dev = atusb->usb_dev;

	dev_dbg(&usb_dev->dev, "atusb_write_reg: 0x%02x <- 0x%02x\n",
	reg, value);
	return atusb_control_msg(atusb, usb_sndctrlpipe(usb_dev, 0),
	ATUSB_REG_WRITE, ATUSB_REQ_TO_DEV,
	value, reg, NULL, 0, 1000);
	}

	static int atusb_read_reg(struct atusb *atusb, uint8_t reg)
	{
	struct usb_device *usb_dev = atusb->usb_dev;
	int ret;
	uint8_t value;

	dev_dbg(&usb_dev->dev, "atusb: reg = 0x%x\n", reg);
	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
	ATUSB_REG_READ, ATUSB_REQ_FROM_DEV,
	0, reg, &value, 1, 1000);
	return ret >= 0 ? value : ret;
	}

	static int atusb_write_subreg(struct atusb *atusb, uint8_t reg, uint8_t mask,
	uint8_t shift, uint8_t value)
	{
	struct usb_device *usb_dev = atusb->usb_dev;
	uint8_t orig, tmp;
	int ret = 0;

	dev_dbg(&usb_dev->dev, "atusb_write_subreg: 0x%02x <- 0x%02x\n",
	reg, value);

	orig = atusb_read_reg(atusb, reg);

	/* Write the value only into that part of the register which is allowed
	* by the mask. All other bits stay as before.
	*/
	tmp = orig & ~mask;
	tmp \|= (value << shift) & mask;

	if (tmp != orig)
	ret = atusb_write_reg(atusb, reg, tmp);

	return ret;
	}

	static int atusb_get_and_clear_error(struct atusb *atusb)
	{
	int err = atusb->err;

	atusb->err = 0;
	return err;
	}

	/* ----- skb allocation ---------------------------------------------------- */

	#define MAX_PSDU 127
	#define MAX_RX_XFER (1 + MAX_PSDU + 2 + 1) /* PHR+PSDU+CRC+LQI */

	#define SKB_ATUSB(skb) ((struct atusb *)(skb)->cb)

	static void atusb_in(struct urb *urb);

	static int atusb_submit_rx_urb(struct atusb atusb, struct urb urb)
	{
	struct usb_device *usb_dev = atusb->usb_dev;
	struct sk_buff *skb = urb->context;
	int ret;

	if (!skb) {
	skb = alloc_skb(MAX_RX_XFER, GFP_KERNEL);
	if (!skb) {
	dev_warn_ratelimited(&usb_dev->dev,
	"atusb_in: can't allocate skb\n");
	return -ENOMEM;
	}
	skb_put(skb, MAX_RX_XFER);
	SKB_ATUSB(skb) = atusb;
	}

	usb_fill_bulk_urb(urb, usb_dev, usb_rcvbulkpipe(usb_dev, 1),
	skb->data, MAX_RX_XFER, atusb_in, skb);
	usb_anchor_urb(urb, &atusb->rx_urbs);

	ret = usb_submit_urb(urb, GFP_KERNEL);
	if (ret) {
	usb_unanchor_urb(urb);
	kfree_skb(skb);
	urb->context = NULL;
	}
	return ret;
	}

	static void atusb_work_urbs(struct work_struct *work)
	{
	struct atusb *atusb =
	container_of(to_delayed_work(work), struct atusb, work);
	struct usb_device *usb_dev = atusb->usb_dev;
	struct urb *urb;
	int ret;

	if (atusb->shutdown)
	return;

	do {
	urb = usb_get_from_anchor(&atusb->idle_urbs);
	if (!urb)
	return;
	ret = atusb_submit_rx_urb(atusb, urb);
	} while (!ret);

	usb_anchor_urb(urb, &atusb->idle_urbs);
	dev_warn_ratelimited(&usb_dev->dev,
	"atusb_in: can't allocate/submit URB (%d)\n", ret);
	schedule_delayed_work(&atusb->work,
	msecs_to_jiffies(ATUSB_ALLOC_DELAY_MS) + 1);
	}

	/* ----- Asynchronous USB -------------------------------------------------- */

	static void atusb_tx_done(struct atusb *atusb, uint8_t seq)
	{
	struct usb_device *usb_dev = atusb->usb_dev;
	uint8_t expect = atusb->tx_ack_seq;

	dev_dbg(&usb_dev->dev, "atusb_tx_done (0x%02x/0x%02x)\n", seq, expect);
	if (seq == expect) {
	/* TODO check for ifs handling in firmware */
	ieee802154_xmit_complete(atusb->hw, atusb->tx_skb, false);
	} else {
	/* TODO I experience this case when atusb has a tx complete
	* irq before probing, we should fix the firmware it's an
	* unlikely case now that seq == expect is then true, but can
	* happen and fail with a tx_skb = NULL;
	*/
	ieee802154_wake_queue(atusb->hw);
	if (atusb->tx_skb)
	dev_kfree_skb_irq(atusb->tx_skb);
	}
	}

	static void atusb_in_good(struct urb *urb)
	{
	struct usb_device *usb_dev = urb->dev;
	struct sk_buff *skb = urb->context;
	struct atusb *atusb = SKB_ATUSB(skb);
	uint8_t len, lqi;

	if (!urb->actual_length) {
	dev_dbg(&usb_dev->dev, "atusb_in: zero-sized URB ?\n");
	return;
	}

	len = *skb->data;

	if (urb->actual_length == 1) {
	atusb_tx_done(atusb, len);
	return;
	}

	if (len + 1 > urb->actual_length - 1) {
	dev_dbg(&usb_dev->dev, "atusb_in: frame len %d+1 > URB %u-1\n",
	len, urb->actual_length);
	return;
	}

	if (!ieee802154_is_valid_psdu_len(len)) {
	dev_dbg(&usb_dev->dev, "atusb_in: frame corrupted\n");
	return;
	}

	lqi = skb->data[len + 1];
	dev_dbg(&usb_dev->dev, "atusb_in: rx len %d lqi 0x%02x\n", len, lqi);
	skb_pull(skb, 1); /* remove PHR */
	skb_trim(skb, len); /* get payload only */
	ieee802154_rx_irqsafe(atusb->hw, skb, lqi);
	urb->context = NULL; /* skb is gone */
	}

	static void atusb_in(struct urb *urb)
	{
	struct usb_device *usb_dev = urb->dev;
	struct sk_buff *skb = urb->context;
	struct atusb *atusb = SKB_ATUSB(skb);

	dev_dbg(&usb_dev->dev, "atusb_in: status %d len %d\n",
	urb->status, urb->actual_length);
	if (urb->status) {
	if (urb->status == -ENOENT) { /* being killed */
	kfree_skb(skb);
	urb->context = NULL;
	return;
	}
	dev_dbg(&usb_dev->dev, "atusb_in: URB error %d\n", urb->status);
	} else {
	atusb_in_good(urb);
	}

	usb_anchor_urb(urb, &atusb->idle_urbs);
	if (!atusb->shutdown)
	schedule_delayed_work(&atusb->work, 0);
	}

	/* ----- URB allocation/deallocation --------------------------------------- */

	static void atusb_free_urbs(struct atusb *atusb)
	{
	struct urb *urb;

	while (1) {
	urb = usb_get_from_anchor(&atusb->idle_urbs);
	if (!urb)
	break;
	if (urb->context)
	kfree_skb(urb->context);
	usb_free_urb(urb);
	}
	}

	static int atusb_alloc_urbs(struct atusb *atusb, int n)
	{
	struct urb *urb;

	while (n) {
	urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!urb) {
	atusb_free_urbs(atusb);
	return -ENOMEM;
	}
	usb_anchor_urb(urb, &atusb->idle_urbs);
	n--;
	}
	return 0;
	}

	/* ----- IEEE 802.15.4 interface operations -------------------------------- */

	static void atusb_xmit_complete(struct urb *urb)
	{
	dev_dbg(&urb->dev->dev, "atusb_xmit urb completed");
	}

	static int atusb_xmit(struct ieee802154_hw hw, struct sk_buff skb)
	{
	struct atusb *atusb = hw->priv;
	struct usb_device *usb_dev = atusb->usb_dev;
	int ret;

	dev_dbg(&usb_dev->dev, "atusb_xmit (%d)\n", skb->len);
	atusb->tx_skb = skb;
	atusb->tx_ack_seq++;
	atusb->tx_dr.wIndex = cpu_to_le16(atusb->tx_ack_seq);
	atusb->tx_dr.wLength = cpu_to_le16(skb->len);

	usb_fill_control_urb(atusb->tx_urb, usb_dev,
	usb_sndctrlpipe(usb_dev, 0),
	(unsigned char *)&atusb->tx_dr, skb->data,
	skb->len, atusb_xmit_complete, NULL);
	ret = usb_submit_urb(atusb->tx_urb, GFP_ATOMIC);
	dev_dbg(&usb_dev->dev, "atusb_xmit done (%d)\n", ret);
	return ret;
	}

	static int atusb_channel(struct ieee802154_hw *hw, u8 page, u8 channel)
	{
	struct atusb *atusb = hw->priv;
	int ret;

	/* This implicitly sets the CCA (Clear Channel Assessment) mode to 0,
	* "Mode 3a, Carrier sense OR energy above threshold".
	* We should probably make this configurable. @@@
	*/
	ret = atusb_write_reg(atusb, RG_PHY_CC_CCA, channel);
	if (ret < 0)
	return ret;
	msleep(1); /* @@@ ugly synchronization */
	return 0;
	}

	static int atusb_ed(struct ieee802154_hw hw, u8 level)
	{
	BUG_ON(!level);
	*level = 0xbe;
	return 0;
	}

	static int atusb_set_hw_addr_filt(struct ieee802154_hw *hw,
	struct ieee802154_hw_addr_filt *filt,
	unsigned long changed)
	{
	struct atusb *atusb = hw->priv;
	struct device *dev = &atusb->usb_dev->dev;

	if (changed & IEEE802154_AFILT_SADDR_CHANGED) {
	u16 addr = le16_to_cpu(filt->short_addr);

	dev_vdbg(dev, "atusb_set_hw_addr_filt called for saddr\n");
	atusb_write_reg(atusb, RG_SHORT_ADDR_0, addr);
	atusb_write_reg(atusb, RG_SHORT_ADDR_1, addr >> 8);
	}

	if (changed & IEEE802154_AFILT_PANID_CHANGED) {
	u16 pan = le16_to_cpu(filt->pan_id);

	dev_vdbg(dev, "atusb_set_hw_addr_filt called for pan id\n");
	atusb_write_reg(atusb, RG_PAN_ID_0, pan);
	atusb_write_reg(atusb, RG_PAN_ID_1, pan >> 8);
	}

	if (changed & IEEE802154_AFILT_IEEEADDR_CHANGED) {
	u8 i, addr[IEEE802154_EXTENDED_ADDR_LEN];

	memcpy(addr, &filt->ieee_addr, IEEE802154_EXTENDED_ADDR_LEN);
	dev_vdbg(dev, "atusb_set_hw_addr_filt called for IEEE addr\n");
	for (i = 0; i < 8; i++)
	atusb_write_reg(atusb, RG_IEEE_ADDR_0 + i, addr[i]);
	}

	if (changed & IEEE802154_AFILT_PANC_CHANGED) {
	dev_vdbg(dev,
	"atusb_set_hw_addr_filt called for panc change\n");
	if (filt->pan_coord)
	atusb_write_subreg(atusb, SR_AACK_I_AM_COORD, 1);
	else
	atusb_write_subreg(atusb, SR_AACK_I_AM_COORD, 0);
	}

	return atusb_get_and_clear_error(atusb);
	}

	static int atusb_start(struct ieee802154_hw *hw)
	{
	struct atusb *atusb = hw->priv;
	struct usb_device *usb_dev = atusb->usb_dev;
	int ret;

	dev_dbg(&usb_dev->dev, "atusb_start\n");
	schedule_delayed_work(&atusb->work, 0);
	atusb_command(atusb, ATUSB_RX_MODE, 1);
	ret = atusb_get_and_clear_error(atusb);
	if (ret < 0)
	usb_kill_anchored_urbs(&atusb->idle_urbs);
	return ret;
	}

	static void atusb_stop(struct ieee802154_hw *hw)
	{
	struct atusb *atusb = hw->priv;
	struct usb_device *usb_dev = atusb->usb_dev;

	dev_dbg(&usb_dev->dev, "atusb_stop\n");
	usb_kill_anchored_urbs(&atusb->idle_urbs);
	atusb_command(atusb, ATUSB_RX_MODE, 0);
	atusb_get_and_clear_error(atusb);
	}

	#define ATUSB_MAX_TX_POWERS 0xF
	static const s32 atusb_powers[ATUSB_MAX_TX_POWERS + 1] = {
	300, 280, 230, 180, 130, 70, 0, -100, -200, -300, -400, -500, -700,
	-900, -1200, -1700,
	};

	static int
	atusb_set_txpower(struct ieee802154_hw *hw, s32 mbm)
	{
	struct atusb *atusb = hw->priv;
	u32 i;

	for (i = 0; i < hw->phy->supported.tx_powers_size; i++) {
	if (hw->phy->supported.tx_powers[i] == mbm)
	return atusb_write_subreg(atusb, SR_TX_PWR_23X, i);
	}

	return -EINVAL;
	}

	static int
	atusb_set_promiscuous_mode(struct ieee802154_hw *hw, const bool on)
	{
	struct atusb *atusb = hw->priv;
	int ret;

	if (on) {
	ret = atusb_write_subreg(atusb, SR_AACK_DIS_ACK, 1);
	if (ret < 0)
	return ret;

	ret = atusb_write_subreg(atusb, SR_AACK_PROM_MODE, 1);
	if (ret < 0)
	return ret;
	} else {
	ret = atusb_write_subreg(atusb, SR_AACK_PROM_MODE, 0);
	if (ret < 0)
	return ret;

	ret = atusb_write_subreg(atusb, SR_AACK_DIS_ACK, 0);
	if (ret < 0)
	return ret;
	}

	return 0;
	}

	static struct ieee802154_ops atusb_ops = {
	.owner = THIS_MODULE,
	.xmit_async = atusb_xmit,
	.ed = atusb_ed,
	.set_channel = atusb_channel,
	.start = atusb_start,
	.stop = atusb_stop,
	.set_hw_addr_filt = atusb_set_hw_addr_filt,
	.set_txpower = atusb_set_txpower,
	.set_promiscuous_mode = atusb_set_promiscuous_mode,
	};

	/* ----- Firmware and chip version information ----------------------------- */

	static int atusb_get_and_show_revision(struct atusb *atusb)
	{
	struct usb_device *usb_dev = atusb->usb_dev;
	unsigned char buffer[3];
	int ret;

	/* Get a couple of the ATMega Firmware values */
	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
	ATUSB_ID, ATUSB_REQ_FROM_DEV, 0, 0,
	buffer, 3, 1000);
	if (ret >= 0)
	dev_info(&usb_dev->dev,
	"Firmware: major: %u, minor: %u, hardware type: %u\n",
	buffer[0], buffer[1], buffer[2]);
	if (buffer[0] == 0 && buffer[1] < 2) {
	dev_info(&usb_dev->dev,
	"Firmware version (%u.%u) is predates our first public release.",
	buffer[0], buffer[1]);
	dev_info(&usb_dev->dev, "Please update to version 0.2 or newer");
	}

	return ret;
	}

	static int atusb_get_and_show_build(struct atusb *atusb)
	{
	struct usb_device *usb_dev = atusb->usb_dev;
	char build[ATUSB_BUILD_SIZE + 1];
	int ret;

	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
	ATUSB_BUILD, ATUSB_REQ_FROM_DEV, 0, 0,
	build, ATUSB_BUILD_SIZE, 1000);
	if (ret >= 0) {
	build[ret] = 0;
	dev_info(&usb_dev->dev, "Firmware: build %s\n", build);
	}

	return ret;
	}

	static int atusb_get_and_show_chip(struct atusb *atusb)
	{
	struct usb_device *usb_dev = atusb->usb_dev;
	uint8_t man_id_0, man_id_1, part_num, version_num;
	const char *chip;

	man_id_0 = atusb_read_reg(atusb, RG_MAN_ID_0);
	man_id_1 = atusb_read_reg(atusb, RG_MAN_ID_1);
	part_num = atusb_read_reg(atusb, RG_PART_NUM);
	version_num = atusb_read_reg(atusb, RG_VERSION_NUM);

	if (atusb->err)
	return atusb->err;

	if ((man_id_1 << 8 \| man_id_0) != ATUSB_JEDEC_ATMEL) {
	dev_err(&usb_dev->dev,
	"non-Atmel transceiver xxxx%02x%02x\n",
	man_id_1, man_id_0);
	goto fail;
	}

	switch (part_num) {
	case 2:
	chip = "AT86RF230";
	break;
	case 3:
	chip = "AT86RF231";
	break;
	default:
	dev_err(&usb_dev->dev,
	"unexpected transceiver, part 0x%02x version 0x%02x\n",
	part_num, version_num);
	goto fail;
	}

	dev_info(&usb_dev->dev, "ATUSB: %s version %d\n", chip, version_num);

	return 0;

	fail:
	atusb->err = -ENODEV;
	return -ENODEV;
	}

	/* ----- Setup ------------------------------------------------------------- */

	static int atusb_probe(struct usb_interface *interface,
	const struct usb_device_id *id)
	{
	struct usb_device *usb_dev = interface_to_usbdev(interface);
	struct ieee802154_hw *hw;
	struct atusb *atusb = NULL;
	int ret = -ENOMEM;

	hw = ieee802154_alloc_hw(sizeof(struct atusb), &atusb_ops);
	if (!hw)
	return -ENOMEM;

	atusb = hw->priv;
	atusb->hw = hw;
	atusb->usb_dev = usb_get_dev(usb_dev);
	usb_set_intfdata(interface, atusb);

	atusb->shutdown = 0;
	atusb->err = 0;
	INIT_DELAYED_WORK(&atusb->work, atusb_work_urbs);
	init_usb_anchor(&atusb->idle_urbs);
	init_usb_anchor(&atusb->rx_urbs);

	if (atusb_alloc_urbs(atusb, ATUSB_NUM_RX_URBS))
	goto fail;

	atusb->tx_dr.bRequestType = ATUSB_REQ_TO_DEV;
	atusb->tx_dr.bRequest = ATUSB_TX;
	atusb->tx_dr.wValue = cpu_to_le16(0);

	atusb->tx_urb = usb_alloc_urb(0, GFP_ATOMIC);
	if (!atusb->tx_urb)
	goto fail;

	hw->parent = &usb_dev->dev;
	hw->flags = IEEE802154_HW_TX_OMIT_CKSUM \| IEEE802154_HW_AFILT \|
	IEEE802154_HW_PROMISCUOUS;

	hw->phy->flags = WPAN_PHY_FLAG_TXPOWER;

	hw->phy->current_page = 0;
	hw->phy->current_channel = 11; /* reset default */
	hw->phy->supported.channels[0] = 0x7FFF800;
	hw->phy->supported.tx_powers = atusb_powers;
	hw->phy->supported.tx_powers_size = ARRAY_SIZE(atusb_powers);
	hw->phy->transmit_power = hw->phy->supported.tx_powers[0];
	ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);

	atusb_command(atusb, ATUSB_RF_RESET, 0);
	atusb_get_and_show_chip(atusb);
	atusb_get_and_show_revision(atusb);
	atusb_get_and_show_build(atusb);
	ret = atusb_get_and_clear_error(atusb);
	if (ret) {
	dev_err(&atusb->usb_dev->dev,
	"%s: initialization failed, error = %d\n",
	__func__, ret);
	goto fail;
	}

	ret = ieee802154_register_hw(hw);
	if (ret)
	goto fail;

	/* If we just powered on, we're now in P_ON and need to enter TRX_OFF
	* explicitly. Any resets after that will send us straight to TRX_OFF,
	* making the command below redundant.
	*/
	atusb_write_reg(atusb, RG_TRX_STATE, STATE_FORCE_TRX_OFF);
	msleep(1); /* reset => TRX_OFF, tTR13 = 37 us */

	#if 0
	/* Calculating the maximum time available to empty the frame buffer
	* on reception:
	*
	* According to [1], the inter-frame gap is
	* R * 20 * 16 us + 128 us
	* where R is a random number from 0 to 7. Furthermore, we have 20 bit
	* times (80 us at 250 kbps) of SHR of the next frame before the
	* transceiver begins storing data in the frame buffer.
	*
	* This yields a minimum time of 208 us between the last data of a
	* frame and the first data of the next frame. This time is further
	* reduced by interrupt latency in the atusb firmware.
	*
	* atusb currently needs about 500 us to retrieve a maximum-sized
	* frame. We therefore have to allow reception of a new frame to begin
	* while we retrieve the previous frame.
	*
	* [1] "JN-AN-1035 Calculating data rates in an IEEE 802.15.4-based
	* network", Jennic 2006.
	* http://www.jennic.com/download_file.php?supportFile=JN-AN-1035%20Calculating%20802-15-4%20Data%20Rates-1v0.pdf
	*/

	atusb_write_subreg(atusb, SR_RX_SAFE_MODE, 1);
	#endif
	atusb_write_reg(atusb, RG_IRQ_MASK, 0xff);

	ret = atusb_get_and_clear_error(atusb);
	if (!ret)
	return 0;

	dev_err(&atusb->usb_dev->dev,
	"%s: setup failed, error = %d\n",
	__func__, ret);

	ieee802154_unregister_hw(hw);
	fail:
	atusb_free_urbs(atusb);
	usb_kill_urb(atusb->tx_urb);
	usb_free_urb(atusb->tx_urb);
	usb_put_dev(usb_dev);
	ieee802154_free_hw(hw);
	return ret;
	}

	static void atusb_disconnect(struct usb_interface *interface)
	{
	struct atusb *atusb = usb_get_intfdata(interface);

	dev_dbg(&atusb->usb_dev->dev, "atusb_disconnect\n");

	atusb->shutdown = 1;
	cancel_delayed_work_sync(&atusb->work);

	usb_kill_anchored_urbs(&atusb->rx_urbs);
	atusb_free_urbs(atusb);
	usb_kill_urb(atusb->tx_urb);
	usb_free_urb(atusb->tx_urb);

	ieee802154_unregister_hw(atusb->hw);

	ieee802154_free_hw(atusb->hw);

	usb_set_intfdata(interface, NULL);
	usb_put_dev(atusb->usb_dev);

	pr_debug("atusb_disconnect done\n");
	}

	/* The devices we work with */
	static const struct usb_device_id atusb_device_table[] = {
	{
	.match_flags = USB_DEVICE_ID_MATCH_DEVICE \|
	USB_DEVICE_ID_MATCH_INT_INFO,
	.idVendor = ATUSB_VENDOR_ID,
	.idProduct = ATUSB_PRODUCT_ID,
	.bInterfaceClass = USB_CLASS_VENDOR_SPEC
	},
	/* end with null element */
	{}
	};
	MODULE_DEVICE_TABLE(usb, atusb_device_table);

	static struct usb_driver atusb_driver = {
	.name = "atusb",
	.probe = atusb_probe,
	.disconnect = atusb_disconnect,
	.id_table = atusb_device_table,
	};
	module_usb_driver(atusb_driver);

	MODULE_AUTHOR("Alexander Aring <alex.aring@gmail.com>");
	MODULE_AUTHOR("Richard Sharpe <realrichardsharpe@gmail.com>");
	MODULE_AUTHOR("Stefan Schmidt <stefan@datenfreihafen.org>");
	MODULE_AUTHOR("Werner Almesberger <werner@almesberger.net>");
	MODULE_DESCRIPTION("ATUSB IEEE 802.15.4 Driver");
	MODULE_LICENSE("GPL");