drivers/net/wireless/orinoco/hermes.c - kernel/prism - Git at Google

 /* hermes.c
  *
  * Driver core for the "Hermes" wireless MAC controller, as used in
  * the Lucent Orinoco and Cabletron RoamAbout cards. It should also
  * work on the hfa3841 and hfa3842 MAC controller chips used in the
  * Prism II chipsets.
  *
  * This is not a complete driver, just low-level access routines for
  * the MAC controller itself.
  *
  * Based on the prism2 driver from Absolute Value Systems' linux-wlan
  * project, the Linux wvlan_cs driver, Lucent's HCF-Light
  * (wvlan_hcf.c) library, and the NetBSD wireless driver (in no
  * particular order).
  *
  * Copyright (C) 2000, David Gibson, Linuxcare Australia.
  * (C) Copyright David Gibson, IBM Corp. 2001-2003.
  *
  * The contents of this file are subject to the Mozilla Public License
  * Version 1.1 (the "License"); you may not use this file except in
  * compliance with the License. You may obtain a copy of the License
  * at http://www.mozilla.org/MPL/
  *
  * Software distributed under the License is distributed on an "AS IS"
  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
  * the License for the specific language governing rights and
  * limitations under the License.
  *
  * Alternatively, the contents of this file may be used under the
  * terms of the GNU General Public License version 2 (the "GPL"), in
  * which case the provisions of the GPL are applicable instead of the
  * above.  If you wish to allow the use of your version of this file
  * only under the terms of the GPL and not to allow others to use your
  * version of this file under the MPL, indicate your decision by
  * deleting the provisions above and replace them with the notice and
  * other provisions required by the GPL.  If you do not delete the
  * provisions above, a recipient may use your version of this file
  * under either the MPL or the GPL.
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/delay.h>

 #include "hermes.h"

 /* These are maximum timeouts. Most often, card wil react much faster */
 #define CMD_BUSY_TIMEOUT (100) /* In iterations of ~1us */
 #define CMD_INIT_TIMEOUT (50000) /* in iterations of ~10us */
 #define CMD_COMPL_TIMEOUT (20000) /* in iterations of ~10us */
 #define ALLOC_COMPL_TIMEOUT (1000) /* in iterations of ~10us */

 /*
  * Debugging helpers
  */

 #define DMSG(stuff...) do {printk(KERN_DEBUG "hermes @ %p: " , hw->iobase); \
 			printk(stuff); } while (0)

 #undef HERMES_DEBUG
 #ifdef HERMES_DEBUG
 #include <stdarg.h>

 #define DEBUG(lvl, stuff...) if ((lvl) <= HERMES_DEBUG) DMSG(stuff)

 #else /* ! HERMES_DEBUG */

 #define DEBUG(lvl, stuff...) do { } while (0)

 #endif /* ! HERMES_DEBUG */


 /*
  * Internal functions
  */

 /* Issue a command to the chip. Waiting for it to complete is the caller's
    problem.

    Returns -EBUSY if the command register is busy, 0 on success.

    Callable from any context.
 */
 static int hermes_issue_cmd(hermes_t *hw, u16 cmd, u16 param0,
 			    u16 param1, u16 param2)
 {
 	int k = CMD_BUSY_TIMEOUT;
 	u16 reg;

 	/* First wait for the command register to unbusy */
 	reg = hermes_read_regn(hw, CMD);
 	while ((reg & HERMES_CMD_BUSY) && k) {
 		k--;
 		udelay(1);
 		reg = hermes_read_regn(hw, CMD);
 	}
 	if (reg & HERMES_CMD_BUSY)
 		return -EBUSY;

 	hermes_write_regn(hw, PARAM2, param2);
 	hermes_write_regn(hw, PARAM1, param1);
 	hermes_write_regn(hw, PARAM0, param0);
 	hermes_write_regn(hw, CMD, cmd);

 	return 0;
 }

 /*
  * Function definitions
  */

 /* For doing cmds that wipe the magic constant in SWSUPPORT0 */
 int hermes_doicmd_wait(hermes_t *hw, u16 cmd,
 		       u16 parm0, u16 parm1, u16 parm2,
 		       struct hermes_response *resp)
 {
 	int err = 0;
 	int k;
 	u16 status, reg;

 	err = hermes_issue_cmd(hw, cmd, parm0, parm1, parm2);
 	if (err)
 		return err;

 	reg = hermes_read_regn(hw, EVSTAT);
 	k = CMD_INIT_TIMEOUT;
 	while ((!(reg & HERMES_EV_CMD)) && k) {
 		k--;
 		udelay(10);
 		reg = hermes_read_regn(hw, EVSTAT);
 	}

 	hermes_write_regn(hw, SWSUPPORT0, HERMES_MAGIC);

 	if (!hermes_present(hw)) {
 		DEBUG(0, "hermes @ 0x%x: Card removed during reset.\n",
 		       hw->iobase);
 		err = -ENODEV;
 		goto out;
 	}

 	if (!(reg & HERMES_EV_CMD)) {
 		printk(KERN_ERR "hermes @ %p: "
 		       "Timeout waiting for card to reset (reg=0x%04x)!\n",
 		       hw->iobase, reg);
 		err = -ETIMEDOUT;
 		goto out;
 	}

 	status = hermes_read_regn(hw, STATUS);
 	if (resp) {
 		resp->status = status;
 		resp->resp0 = hermes_read_regn(hw, RESP0);
 		resp->resp1 = hermes_read_regn(hw, RESP1);
 		resp->resp2 = hermes_read_regn(hw, RESP2);
 	}

 	hermes_write_regn(hw, EVACK, HERMES_EV_CMD);

 	if (status & HERMES_STATUS_RESULT)
 		err = -EIO;
 out:
 	return err;
 }
 EXPORT_SYMBOL(hermes_doicmd_wait);

 void hermes_struct_init(hermes_t *hw, void __iomem *address, int reg_spacing)
 {
 	hw->iobase = address;
 	hw->reg_spacing = reg_spacing;
 	hw->inten = 0x0;
 }
 EXPORT_SYMBOL(hermes_struct_init);

 int hermes_init(hermes_t *hw)
 {
 	u16 reg;
 	int err = 0;
 	int k;

 	/* We don't want to be interrupted while resetting the chipset */
 	hw->inten = 0x0;
 	hermes_write_regn(hw, INTEN, 0);
 	hermes_write_regn(hw, EVACK, 0xffff);

 	/* Normally it's a "can't happen" for the command register to
 	   be busy when we go to issue a command because we are
 	   serializing all commands.  However we want to have some
 	   chance of resetting the card even if it gets into a stupid
 	   state, so we actually wait to see if the command register
 	   will unbusy itself here. */
 	k = CMD_BUSY_TIMEOUT;
 	reg = hermes_read_regn(hw, CMD);
 	while (k && (reg & HERMES_CMD_BUSY)) {
 		if (reg == 0xffff) /* Special case - the card has probably been
 				      removed, so don't wait for the timeout */
 			return -ENODEV;

 		k--;
 		udelay(1);
 		reg = hermes_read_regn(hw, CMD);
 	}

 	/* No need to explicitly handle the timeout - if we've timed
 	   out hermes_issue_cmd() will probably return -EBUSY below */

 	/* According to the documentation, EVSTAT may contain
 	   obsolete event occurrence information.  We have to acknowledge
 	   it by writing EVACK. */
 	reg = hermes_read_regn(hw, EVSTAT);
 	hermes_write_regn(hw, EVACK, reg);

 	/* We don't use hermes_docmd_wait here, because the reset wipes
 	   the magic constant in SWSUPPORT0 away, and it gets confused */
 	err = hermes_doicmd_wait(hw, HERMES_CMD_INIT, 0, 0, 0, NULL);

 	return err;
 }
 EXPORT_SYMBOL(hermes_init);

 /* Issue a command to the chip, and (busy!) wait for it to
  * complete.
  *
  * Returns:
  *     < 0 on internal error
  *       0 on success
  *     > 0 on error returned by the firmware
  *
  * Callable from any context, but locking is your problem. */
 int hermes_docmd_wait(hermes_t *hw, u16 cmd, u16 parm0,
 		      struct hermes_response *resp)
 {
 	int err;
 	int k;
 	u16 reg;
 	u16 status;

 	err = hermes_issue_cmd(hw, cmd, parm0, 0, 0);
 	if (err) {
 		if (!hermes_present(hw)) {
 			if (net_ratelimit())
 				printk(KERN_WARNING "hermes @ %p: "
 				       "Card removed while issuing command "
 				       "0x%04x.\n", hw->iobase, cmd);
 			err = -ENODEV;
 		} else
 			if (net_ratelimit())
 				printk(KERN_ERR "hermes @ %p: "
 				       "Error %d issuing command 0x%04x.\n",
 				       hw->iobase, err, cmd);
 		goto out;
 	}

 	reg = hermes_read_regn(hw, EVSTAT);
 	k = CMD_COMPL_TIMEOUT;
 	while ((!(reg & HERMES_EV_CMD)) && k) {
 		k--;
 		udelay(10);
 		reg = hermes_read_regn(hw, EVSTAT);
 	}

 	if (!hermes_present(hw)) {
 		printk(KERN_WARNING "hermes @ %p: Card removed "
 		       "while waiting for command 0x%04x completion.\n",
 		       hw->iobase, cmd);
 		err = -ENODEV;
 		goto out;
 	}

 	if (!(reg & HERMES_EV_CMD)) {
 		printk(KERN_ERR "hermes @ %p: Timeout waiting for "
 		       "command 0x%04x completion.\n", hw->iobase, cmd);
 		err = -ETIMEDOUT;
 		goto out;
 	}

 	status = hermes_read_regn(hw, STATUS);
 	if (resp) {
 		resp->status = status;
 		resp->resp0 = hermes_read_regn(hw, RESP0);
 		resp->resp1 = hermes_read_regn(hw, RESP1);
 		resp->resp2 = hermes_read_regn(hw, RESP2);
 	}

 	hermes_write_regn(hw, EVACK, HERMES_EV_CMD);

 	if (status & HERMES_STATUS_RESULT)
 		err = -EIO;

  out:
 	return err;
 }
 EXPORT_SYMBOL(hermes_docmd_wait);

 int hermes_allocate(hermes_t *hw, u16 size, u16 *fid)
 {
 	int err = 0;
 	int k;
 	u16 reg;

 	if ((size < HERMES_ALLOC_LEN_MIN) || (size > HERMES_ALLOC_LEN_MAX))
 		return -EINVAL;

 	err = hermes_docmd_wait(hw, HERMES_CMD_ALLOC, size, NULL);
 	if (err)
 		return err;

 	reg = hermes_read_regn(hw, EVSTAT);
 	k = ALLOC_COMPL_TIMEOUT;
 	while ((!(reg & HERMES_EV_ALLOC)) && k) {
 		k--;
 		udelay(10);
 		reg = hermes_read_regn(hw, EVSTAT);
 	}

 	if (!hermes_present(hw)) {
 		printk(KERN_WARNING "hermes @ %p: "
 		       "Card removed waiting for frame allocation.\n",
 		       hw->iobase);
 		return -ENODEV;
 	}

 	if (!(reg & HERMES_EV_ALLOC)) {
 		printk(KERN_ERR "hermes @ %p: "
 		       "Timeout waiting for frame allocation\n",
 		       hw->iobase);
 		return -ETIMEDOUT;
 	}

 	*fid = hermes_read_regn(hw, ALLOCFID);
 	hermes_write_regn(hw, EVACK, HERMES_EV_ALLOC);

 	return 0;
 }
 EXPORT_SYMBOL(hermes_allocate);

 /* Set up a BAP to read a particular chunk of data from card's internal buffer.
  *
  * Returns:
  *     < 0 on internal failure (errno)
  *       0 on success
  *     > 0 on error
  * from firmware
  *
  * Callable from any context */
 static int hermes_bap_seek(hermes_t *hw, int bap, u16 id, u16 offset)
 {
 	int sreg = bap ? HERMES_SELECT1 : HERMES_SELECT0;
 	int oreg = bap ? HERMES_OFFSET1 : HERMES_OFFSET0;
 	int k;
 	u16 reg;

 	/* Paranoia.. */
 	if ((offset > HERMES_BAP_OFFSET_MAX) || (offset % 2))
 		return -EINVAL;

 	k = HERMES_BAP_BUSY_TIMEOUT;
 	reg = hermes_read_reg(hw, oreg);
 	while ((reg & HERMES_OFFSET_BUSY) && k) {
 		k--;
 		udelay(1);
 		reg = hermes_read_reg(hw, oreg);
 	}

 	if (reg & HERMES_OFFSET_BUSY)
 		return -ETIMEDOUT;

 	/* Now we actually set up the transfer */
 	hermes_write_reg(hw, sreg, id);
 	hermes_write_reg(hw, oreg, offset);

 	/* Wait for the BAP to be ready */
 	k = HERMES_BAP_BUSY_TIMEOUT;
 	reg = hermes_read_reg(hw, oreg);
 	while ((reg & (HERMES_OFFSET_BUSY | HERMES_OFFSET_ERR)) && k) {
 		k--;
 		udelay(1);
 		reg = hermes_read_reg(hw, oreg);
 	}

 	if (reg != offset) {
 		printk(KERN_ERR "hermes @ %p: BAP%d offset %s: "
 		       "reg=0x%x id=0x%x offset=0x%x\n", hw->iobase, bap,
 		       (reg & HERMES_OFFSET_BUSY) ? "timeout" : "error",
 		       reg, id, offset);

 		if (reg & HERMES_OFFSET_BUSY)
 			return -ETIMEDOUT;

 		return -EIO;		/* error or wrong offset */
 	}

 	return 0;
 }

 /* Read a block of data from the chip's buffer, via the
  * BAP. Synchronization/serialization is the caller's problem.  len
  * must be even.
  *
  * Returns:
  *     < 0 on internal failure (errno)
  *       0 on success
  *     > 0 on error from firmware
  */
 int hermes_bap_pread(hermes_t *hw, int bap, void *buf, int len,
 		     u16 id, u16 offset)
 {
 	int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 	int err = 0;

 	if ((len < 0) || (len % 2))
 		return -EINVAL;

 	err = hermes_bap_seek(hw, bap, id, offset);
 	if (err)
 		goto out;

 	/* Actually do the transfer */
 	hermes_read_words(hw, dreg, buf, len/2);

  out:
 	return err;
 }
 EXPORT_SYMBOL(hermes_bap_pread);

 /* Write a block of data to the chip's buffer, via the
  * BAP. Synchronization/serialization is the caller's problem.
  *
  * Returns:
  *     < 0 on internal failure (errno)
  *       0 on success
  *     > 0 on error from firmware
  */
 int hermes_bap_pwrite(hermes_t *hw, int bap, const void *buf, int len,
 		      u16 id, u16 offset)
 {
 	int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 	int err = 0;

 	if (len < 0)
 		return -EINVAL;

 	err = hermes_bap_seek(hw, bap, id, offset);
 	if (err)
 		goto out;

 	/* Actually do the transfer */
 	hermes_write_bytes(hw, dreg, buf, len);

  out:
 	return err;
 }
 EXPORT_SYMBOL(hermes_bap_pwrite);

 /* Read a Length-Type-Value record from the card.
  *
  * If length is NULL, we ignore the length read from the card, and
  * read the entire buffer regardless. This is useful because some of
  * the configuration records appear to have incorrect lengths in
  * practice.
  *
  * Callable from user or bh context.  */
 int hermes_read_ltv(hermes_t *hw, int bap, u16 rid, unsigned bufsize,
 		    u16 *length, void *buf)
 {
 	int err = 0;
 	int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 	u16 rlength, rtype;
 	unsigned nwords;

 	if (bufsize % 2)
 		return -EINVAL;

 	err = hermes_docmd_wait(hw, HERMES_CMD_ACCESS, rid, NULL);
 	if (err)
 		return err;

 	err = hermes_bap_seek(hw, bap, rid, 0);
 	if (err)
 		return err;

 	rlength = hermes_read_reg(hw, dreg);

 	if (!rlength)
 		return -ENODATA;

 	rtype = hermes_read_reg(hw, dreg);

 	if (length)
 		*length = rlength;

 	if (rtype != rid)
 		printk(KERN_WARNING "hermes @ %p: %s(): "
 		       "rid (0x%04x) does not match type (0x%04x)\n",
 		       hw->iobase, __func__, rid, rtype);
 	if (HERMES_RECLEN_TO_BYTES(rlength) > bufsize)
 		printk(KERN_WARNING "hermes @ %p: "
 		       "Truncating LTV record from %d to %d bytes. "
 		       "(rid=0x%04x, len=0x%04x)\n", hw->iobase,
 		       HERMES_RECLEN_TO_BYTES(rlength), bufsize, rid, rlength);

 	nwords = min((unsigned)rlength - 1, bufsize / 2);
 	hermes_read_words(hw, dreg, buf, nwords);

 	return 0;
 }
 EXPORT_SYMBOL(hermes_read_ltv);

 int hermes_write_ltv(hermes_t *hw, int bap, u16 rid,
 		     u16 length, const void *value)
 {
 	int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 	int err = 0;
 	unsigned count;

 	if (length == 0)
 		return -EINVAL;

 	err = hermes_bap_seek(hw, bap, rid, 0);
 	if (err)
 		return err;

 	hermes_write_reg(hw, dreg, length);
 	hermes_write_reg(hw, dreg, rid);

 	count = length - 1;

 	hermes_write_bytes(hw, dreg, value, count << 1);

 	err = hermes_docmd_wait(hw, HERMES_CMD_ACCESS | HERMES_CMD_WRITE,
 				rid, NULL);

 	return err;
 }
 EXPORT_SYMBOL(hermes_write_ltv);
	/* hermes.c
	*
	* Driver core for the "Hermes" wireless MAC controller, as used in
	* the Lucent Orinoco and Cabletron RoamAbout cards. It should also
	* work on the hfa3841 and hfa3842 MAC controller chips used in the
	* Prism II chipsets.
	*
	* This is not a complete driver, just low-level access routines for
	* the MAC controller itself.
	*
	* Based on the prism2 driver from Absolute Value Systems' linux-wlan
	* project, the Linux wvlan_cs driver, Lucent's HCF-Light
	* (wvlan_hcf.c) library, and the NetBSD wireless driver (in no
	* particular order).
	*
	* Copyright (C) 2000, David Gibson, Linuxcare Australia.
	* (C) Copyright David Gibson, IBM Corp. 2001-2003.
	*
	* The contents of this file are subject to the Mozilla Public License
	* Version 1.1 (the "License"); you may not use this file except in
	* compliance with the License. You may obtain a copy of the License
	* at http://www.mozilla.org/MPL/
	*
	* Software distributed under the License is distributed on an "AS IS"
	* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
	* the License for the specific language governing rights and
	* limitations under the License.
	*
	* Alternatively, the contents of this file may be used under the
	* terms of the GNU General Public License version 2 (the "GPL"), in
	* which case the provisions of the GPL are applicable instead of the
	* above. If you wish to allow the use of your version of this file
	* only under the terms of the GPL and not to allow others to use your
	* version of this file under the MPL, indicate your decision by
	* deleting the provisions above and replace them with the notice and
	* other provisions required by the GPL. If you do not delete the
	* provisions above, a recipient may use your version of this file
	* under either the MPL or the GPL.
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/delay.h>

	#include "hermes.h"

	/* These are maximum timeouts. Most often, card wil react much faster */
	#define CMD_BUSY_TIMEOUT (100) /* In iterations of ~1us */
	#define CMD_INIT_TIMEOUT (50000) /* in iterations of ~10us */
	#define CMD_COMPL_TIMEOUT (20000) /* in iterations of ~10us */
	#define ALLOC_COMPL_TIMEOUT (1000) /* in iterations of ~10us */

	/*
	* Debugging helpers
	*/

	#define DMSG(stuff...) do {printk(KERN_DEBUG "hermes @ %p: " , hw->iobase); \
	printk(stuff); } while (0)

	#undef HERMES_DEBUG
	#ifdef HERMES_DEBUG
	#include <stdarg.h>

	#define DEBUG(lvl, stuff...) if ((lvl) <= HERMES_DEBUG) DMSG(stuff)

	#else /* ! HERMES_DEBUG */

	#define DEBUG(lvl, stuff...) do { } while (0)

	#endif /* ! HERMES_DEBUG */


	/*
	* Internal functions
	*/

	/* Issue a command to the chip. Waiting for it to complete is the caller's
	problem.

	Returns -EBUSY if the command register is busy, 0 on success.

	Callable from any context.
	*/
	static int hermes_issue_cmd(hermes_t *hw, u16 cmd, u16 param0,
	u16 param1, u16 param2)
	{
	int k = CMD_BUSY_TIMEOUT;
	u16 reg;

	/* First wait for the command register to unbusy */
	reg = hermes_read_regn(hw, CMD);
	while ((reg & HERMES_CMD_BUSY) && k) {
	k--;
	udelay(1);
	reg = hermes_read_regn(hw, CMD);
	}
	if (reg & HERMES_CMD_BUSY)
	return -EBUSY;

	hermes_write_regn(hw, PARAM2, param2);
	hermes_write_regn(hw, PARAM1, param1);
	hermes_write_regn(hw, PARAM0, param0);
	hermes_write_regn(hw, CMD, cmd);

	return 0;
	}

	/*
	* Function definitions
	*/

	/* For doing cmds that wipe the magic constant in SWSUPPORT0 */
	int hermes_doicmd_wait(hermes_t *hw, u16 cmd,
	u16 parm0, u16 parm1, u16 parm2,
	struct hermes_response *resp)
	{
	int err = 0;
	int k;
	u16 status, reg;

	err = hermes_issue_cmd(hw, cmd, parm0, parm1, parm2);
	if (err)
	return err;

	reg = hermes_read_regn(hw, EVSTAT);
	k = CMD_INIT_TIMEOUT;
	while ((!(reg & HERMES_EV_CMD)) && k) {
	k--;
	udelay(10);
	reg = hermes_read_regn(hw, EVSTAT);
	}

	hermes_write_regn(hw, SWSUPPORT0, HERMES_MAGIC);

	if (!hermes_present(hw)) {
	DEBUG(0, "hermes @ 0x%x: Card removed during reset.\n",
	hw->iobase);
	err = -ENODEV;
	goto out;
	}

	if (!(reg & HERMES_EV_CMD)) {
	printk(KERN_ERR "hermes @ %p: "
	"Timeout waiting for card to reset (reg=0x%04x)!\n",
	hw->iobase, reg);
	err = -ETIMEDOUT;
	goto out;
	}

	status = hermes_read_regn(hw, STATUS);
	if (resp) {
	resp->status = status;
	resp->resp0 = hermes_read_regn(hw, RESP0);
	resp->resp1 = hermes_read_regn(hw, RESP1);
	resp->resp2 = hermes_read_regn(hw, RESP2);
	}

	hermes_write_regn(hw, EVACK, HERMES_EV_CMD);

	if (status & HERMES_STATUS_RESULT)
	err = -EIO;
	out:
	return err;
	}
	EXPORT_SYMBOL(hermes_doicmd_wait);

	void hermes_struct_init(hermes_t hw, void __iomem address, int reg_spacing)
	{
	hw->iobase = address;
	hw->reg_spacing = reg_spacing;
	hw->inten = 0x0;
	}
	EXPORT_SYMBOL(hermes_struct_init);

	int hermes_init(hermes_t *hw)
	{
	u16 reg;
	int err = 0;
	int k;

	/* We don't want to be interrupted while resetting the chipset */
	hw->inten = 0x0;
	hermes_write_regn(hw, INTEN, 0);
	hermes_write_regn(hw, EVACK, 0xffff);

	/* Normally it's a "can't happen" for the command register to
	be busy when we go to issue a command because we are
	serializing all commands. However we want to have some
	chance of resetting the card even if it gets into a stupid
	state, so we actually wait to see if the command register
	will unbusy itself here. */
	k = CMD_BUSY_TIMEOUT;
	reg = hermes_read_regn(hw, CMD);
	while (k && (reg & HERMES_CMD_BUSY)) {
	if (reg == 0xffff) /* Special case - the card has probably been
	removed, so don't wait for the timeout */
	return -ENODEV;

	k--;
	udelay(1);
	reg = hermes_read_regn(hw, CMD);
	}

	/* No need to explicitly handle the timeout - if we've timed
	out hermes_issue_cmd() will probably return -EBUSY below */

	/* According to the documentation, EVSTAT may contain
	obsolete event occurrence information. We have to acknowledge
	it by writing EVACK. */
	reg = hermes_read_regn(hw, EVSTAT);
	hermes_write_regn(hw, EVACK, reg);

	/* We don't use hermes_docmd_wait here, because the reset wipes
	the magic constant in SWSUPPORT0 away, and it gets confused */
	err = hermes_doicmd_wait(hw, HERMES_CMD_INIT, 0, 0, 0, NULL);

	return err;
	}
	EXPORT_SYMBOL(hermes_init);

	/* Issue a command to the chip, and (busy!) wait for it to
	* complete.
	*
	* Returns:
	* < 0 on internal error
	* 0 on success
	* > 0 on error returned by the firmware
	*
	* Callable from any context, but locking is your problem. */
	int hermes_docmd_wait(hermes_t *hw, u16 cmd, u16 parm0,
	struct hermes_response *resp)
	{
	int err;
	int k;
	u16 reg;
	u16 status;

	err = hermes_issue_cmd(hw, cmd, parm0, 0, 0);
	if (err) {
	if (!hermes_present(hw)) {
	if (net_ratelimit())
	printk(KERN_WARNING "hermes @ %p: "
	"Card removed while issuing command "
	"0x%04x.\n", hw->iobase, cmd);
	err = -ENODEV;
	} else
	if (net_ratelimit())
	printk(KERN_ERR "hermes @ %p: "
	"Error %d issuing command 0x%04x.\n",
	hw->iobase, err, cmd);
	goto out;
	}

	reg = hermes_read_regn(hw, EVSTAT);
	k = CMD_COMPL_TIMEOUT;
	while ((!(reg & HERMES_EV_CMD)) && k) {
	k--;
	udelay(10);
	reg = hermes_read_regn(hw, EVSTAT);
	}

	if (!hermes_present(hw)) {
	printk(KERN_WARNING "hermes @ %p: Card removed "
	"while waiting for command 0x%04x completion.\n",
	hw->iobase, cmd);
	err = -ENODEV;
	goto out;
	}

	if (!(reg & HERMES_EV_CMD)) {
	printk(KERN_ERR "hermes @ %p: Timeout waiting for "
	"command 0x%04x completion.\n", hw->iobase, cmd);
	err = -ETIMEDOUT;
	goto out;
	}

	status = hermes_read_regn(hw, STATUS);
	if (resp) {
	resp->status = status;
	resp->resp0 = hermes_read_regn(hw, RESP0);
	resp->resp1 = hermes_read_regn(hw, RESP1);
	resp->resp2 = hermes_read_regn(hw, RESP2);
	}

	hermes_write_regn(hw, EVACK, HERMES_EV_CMD);

	if (status & HERMES_STATUS_RESULT)
	err = -EIO;

	out:
	return err;
	}
	EXPORT_SYMBOL(hermes_docmd_wait);

	int hermes_allocate(hermes_t hw, u16 size, u16 fid)
	{
	int err = 0;
	int k;
	u16 reg;

	if ((size < HERMES_ALLOC_LEN_MIN) \|\| (size > HERMES_ALLOC_LEN_MAX))
	return -EINVAL;

	err = hermes_docmd_wait(hw, HERMES_CMD_ALLOC, size, NULL);
	if (err)
	return err;

	reg = hermes_read_regn(hw, EVSTAT);
	k = ALLOC_COMPL_TIMEOUT;
	while ((!(reg & HERMES_EV_ALLOC)) && k) {
	k--;
	udelay(10);
	reg = hermes_read_regn(hw, EVSTAT);
	}

	if (!hermes_present(hw)) {
	printk(KERN_WARNING "hermes @ %p: "
	"Card removed waiting for frame allocation.\n",
	hw->iobase);
	return -ENODEV;
	}

	if (!(reg & HERMES_EV_ALLOC)) {
	printk(KERN_ERR "hermes @ %p: "
	"Timeout waiting for frame allocation\n",
	hw->iobase);
	return -ETIMEDOUT;
	}

	*fid = hermes_read_regn(hw, ALLOCFID);
	hermes_write_regn(hw, EVACK, HERMES_EV_ALLOC);

	return 0;
	}
	EXPORT_SYMBOL(hermes_allocate);

	/* Set up a BAP to read a particular chunk of data from card's internal buffer.
	*
	* Returns:
	* < 0 on internal failure (errno)
	* 0 on success
	* > 0 on error
	* from firmware
	*
	* Callable from any context */
	static int hermes_bap_seek(hermes_t *hw, int bap, u16 id, u16 offset)
	{
	int sreg = bap ? HERMES_SELECT1 : HERMES_SELECT0;
	int oreg = bap ? HERMES_OFFSET1 : HERMES_OFFSET0;
	int k;
	u16 reg;

	/* Paranoia.. */
	if ((offset > HERMES_BAP_OFFSET_MAX) \|\| (offset % 2))
	return -EINVAL;

	k = HERMES_BAP_BUSY_TIMEOUT;
	reg = hermes_read_reg(hw, oreg);
	while ((reg & HERMES_OFFSET_BUSY) && k) {
	k--;
	udelay(1);
	reg = hermes_read_reg(hw, oreg);
	}

	if (reg & HERMES_OFFSET_BUSY)
	return -ETIMEDOUT;

	/* Now we actually set up the transfer */
	hermes_write_reg(hw, sreg, id);
	hermes_write_reg(hw, oreg, offset);

	/* Wait for the BAP to be ready */
	k = HERMES_BAP_BUSY_TIMEOUT;
	reg = hermes_read_reg(hw, oreg);
	while ((reg & (HERMES_OFFSET_BUSY \| HERMES_OFFSET_ERR)) && k) {
	k--;
	udelay(1);
	reg = hermes_read_reg(hw, oreg);
	}

	if (reg != offset) {
	printk(KERN_ERR "hermes @ %p: BAP%d offset %s: "
	"reg=0x%x id=0x%x offset=0x%x\n", hw->iobase, bap,
	(reg & HERMES_OFFSET_BUSY) ? "timeout" : "error",
	reg, id, offset);

	if (reg & HERMES_OFFSET_BUSY)
	return -ETIMEDOUT;

	return -EIO; /* error or wrong offset */
	}

	return 0;
	}

	/* Read a block of data from the chip's buffer, via the
	* BAP. Synchronization/serialization is the caller's problem. len
	* must be even.
	*
	* Returns:
	* < 0 on internal failure (errno)
	* 0 on success
	* > 0 on error from firmware
	*/
	int hermes_bap_pread(hermes_t hw, int bap, void buf, int len,
	u16 id, u16 offset)
	{
	int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
	int err = 0;

	if ((len < 0) \|\| (len % 2))
	return -EINVAL;

	err = hermes_bap_seek(hw, bap, id, offset);
	if (err)
	goto out;

	/* Actually do the transfer */
	hermes_read_words(hw, dreg, buf, len/2);

	out:
	return err;
	}
	EXPORT_SYMBOL(hermes_bap_pread);

	/* Write a block of data to the chip's buffer, via the
	* BAP. Synchronization/serialization is the caller's problem.
	*
	* Returns:
	* < 0 on internal failure (errno)
	* 0 on success
	* > 0 on error from firmware
	*/
	int hermes_bap_pwrite(hermes_t hw, int bap, const void buf, int len,
	u16 id, u16 offset)
	{
	int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
	int err = 0;

	if (len < 0)
	return -EINVAL;

	err = hermes_bap_seek(hw, bap, id, offset);
	if (err)
	goto out;

	/* Actually do the transfer */
	hermes_write_bytes(hw, dreg, buf, len);

	out:
	return err;
	}
	EXPORT_SYMBOL(hermes_bap_pwrite);

	/* Read a Length-Type-Value record from the card.
	*
	* If length is NULL, we ignore the length read from the card, and
	* read the entire buffer regardless. This is useful because some of
	* the configuration records appear to have incorrect lengths in
	* practice.
	*
	* Callable from user or bh context. */
	int hermes_read_ltv(hermes_t *hw, int bap, u16 rid, unsigned bufsize,
	u16 length, void buf)
	{
	int err = 0;
	int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
	u16 rlength, rtype;
	unsigned nwords;

	if (bufsize % 2)
	return -EINVAL;

	err = hermes_docmd_wait(hw, HERMES_CMD_ACCESS, rid, NULL);
	if (err)
	return err;

	err = hermes_bap_seek(hw, bap, rid, 0);
	if (err)
	return err;

	rlength = hermes_read_reg(hw, dreg);

	if (!rlength)
	return -ENODATA;

	rtype = hermes_read_reg(hw, dreg);

	if (length)
	*length = rlength;

	if (rtype != rid)
	printk(KERN_WARNING "hermes @ %p: %s(): "
	"rid (0x%04x) does not match type (0x%04x)\n",
	hw->iobase, __func__, rid, rtype);
	if (HERMES_RECLEN_TO_BYTES(rlength) > bufsize)
	printk(KERN_WARNING "hermes @ %p: "
	"Truncating LTV record from %d to %d bytes. "
	"(rid=0x%04x, len=0x%04x)\n", hw->iobase,
	HERMES_RECLEN_TO_BYTES(rlength), bufsize, rid, rlength);

	nwords = min((unsigned)rlength - 1, bufsize / 2);
	hermes_read_words(hw, dreg, buf, nwords);

	return 0;
	}
	EXPORT_SYMBOL(hermes_read_ltv);

	int hermes_write_ltv(hermes_t *hw, int bap, u16 rid,
	u16 length, const void *value)
	{
	int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
	int err = 0;
	unsigned count;

	if (length == 0)
	return -EINVAL;

	err = hermes_bap_seek(hw, bap, rid, 0);
	if (err)
	return err;

	hermes_write_reg(hw, dreg, length);
	hermes_write_reg(hw, dreg, rid);

	count = length - 1;

	hermes_write_bytes(hw, dreg, value, count << 1);

	err = hermes_docmd_wait(hw, HERMES_CMD_ACCESS \| HERMES_CMD_WRITE,
	rid, NULL);

	return err;
	}
	EXPORT_SYMBOL(hermes_write_ltv);