/* 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"
MODULE_DESCRIPTION("Low-level driver helper for Lucent Hermes chipset and Prism II HFA384x wireless MAC controller");
MODULE_AUTHOR("Pavel Roskin <proski@gnu.org>"
" & David Gibson <hermes@gibson.dropbear.id.au>");
MODULE_LICENSE("Dual MPL/GPL");
/* 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)
{
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, 0);
hermes_write_regn(hw, PARAM1, 0);
hermes_write_regn(hw, PARAM0, param0);
hermes_write_regn(hw, CMD, cmd);
return 0;
}
/*
* Function definitions
*/
void hermes_struct_init(hermes_t *hw, void __iomem *address, int reg_spacing)
{
hw->iobase = address;
hw->reg_spacing = reg_spacing;
hw->inten = 0x0;
}
int hermes_init(hermes_t *hw)
{
u16 status, 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_issue_cmd(hw, HERMES_CMD_INIT, 0);
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);
hermes_write_regn(hw, EVACK, HERMES_EV_CMD);
if (status & HERMES_STATUS_RESULT)
err = -EIO;
out:
return err;
}
/* 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);
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;
}
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;
}
/* 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;
}
/* 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;
}
/* 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 < 0) || (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, __FUNCTION__, 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;
}
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_struct_init);
EXPORT_SYMBOL(hermes_init);
EXPORT_SYMBOL(hermes_docmd_wait);
EXPORT_SYMBOL(hermes_allocate);
EXPORT_SYMBOL(hermes_bap_pread);
EXPORT_SYMBOL(hermes_bap_pwrite);
EXPORT_SYMBOL(hermes_read_ltv);
EXPORT_SYMBOL(hermes_write_ltv);
static int __init init_hermes(void)
{
return 0;
}
static void __exit exit_hermes(void)
{
}
module_init(init_hermes);
module_exit(exit_hermes);
