kernel-ark/drivers/net/wireless/zd1211rw/zd_ieee80211.c
Daniel Drake 35f2c7c0ce [PATCH] zd1211rw: Allow channels 1-13 in Japan
Eric Goff found that he could not use his ZD1211 device which is
programmed for the Japan regulatory domain. It turns out that ZyDAS
deviate from the spec here: they do not use the newer Japan region code
(0x41) but their drivers do operate as if the newer Japan legal
frequency range is in effect.

Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2006-12-02 00:12:05 -05:00

194 lines
4.3 KiB
C

/* zd_ieee80211.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* A lot of this code is generic and should be moved into the upper layers
* at some point.
*/
#include <linux/errno.h>
#include <linux/wireless.h>
#include <linux/kernel.h>
#include <net/ieee80211.h>
#include "zd_def.h"
#include "zd_ieee80211.h"
#include "zd_mac.h"
static const struct channel_range channel_ranges[] = {
[0] = { 0, 0},
[ZD_REGDOMAIN_FCC] = { 1, 12},
[ZD_REGDOMAIN_IC] = { 1, 12},
[ZD_REGDOMAIN_ETSI] = { 1, 14},
[ZD_REGDOMAIN_JAPAN] = { 1, 14},
[ZD_REGDOMAIN_SPAIN] = { 1, 14},
[ZD_REGDOMAIN_FRANCE] = { 1, 14},
/* Japan originally only had channel 14 available (see CHNL_ID 0x40 in
* 802.11). However, in 2001 the range was extended to include channels
* 1-13. The ZyDAS devices still use the old region code but are
* designed to allow the extra channel access in Japan. */
[ZD_REGDOMAIN_JAPAN_ADD] = { 1, 15},
};
const struct channel_range *zd_channel_range(u8 regdomain)
{
if (regdomain >= ARRAY_SIZE(channel_ranges))
regdomain = 0;
return &channel_ranges[regdomain];
}
int zd_regdomain_supports_channel(u8 regdomain, u8 channel)
{
const struct channel_range *range = zd_channel_range(regdomain);
return range->start <= channel && channel < range->end;
}
int zd_regdomain_supported(u8 regdomain)
{
const struct channel_range *range = zd_channel_range(regdomain);
return range->start != 0;
}
/* Stores channel frequencies in MHz. */
static const u16 channel_frequencies[] = {
2412, 2417, 2422, 2427, 2432, 2437, 2442, 2447,
2452, 2457, 2462, 2467, 2472, 2484,
};
#define NUM_CHANNELS ARRAY_SIZE(channel_frequencies)
static int compute_freq(struct iw_freq *freq, u32 mhz, u32 hz)
{
u32 factor;
freq->e = 0;
if (mhz >= 1000000000U) {
pr_debug("zd1211 mhz %u to large\n", mhz);
freq->m = 0;
return -EINVAL;
}
factor = 1000;
while (mhz >= factor) {
freq->e += 1;
factor *= 10;
}
factor /= 1000U;
freq->m = mhz * (1000000U/factor) + hz/factor;
return 0;
}
int zd_channel_to_freq(struct iw_freq *freq, u8 channel)
{
if (channel > NUM_CHANNELS) {
freq->m = 0;
freq->e = 0;
return -EINVAL;
}
if (!channel) {
freq->m = 0;
freq->e = 0;
return -EINVAL;
}
return compute_freq(freq, channel_frequencies[channel-1], 0);
}
static int freq_to_mhz(const struct iw_freq *freq)
{
u32 factor;
int e;
/* Such high frequencies are not supported. */
if (freq->e > 6)
return -EINVAL;
factor = 1;
for (e = freq->e; e > 0; --e) {
factor *= 10;
}
factor = 1000000U / factor;
if (freq->m % factor) {
return -EINVAL;
}
return freq->m / factor;
}
int zd_find_channel(u8 *channel, const struct iw_freq *freq)
{
int i, r;
u32 mhz;
if (freq->m < 1000) {
if (freq->m > NUM_CHANNELS || freq->m == 0)
return -EINVAL;
*channel = freq->m;
return 1;
}
r = freq_to_mhz(freq);
if (r < 0)
return r;
mhz = r;
for (i = 0; i < NUM_CHANNELS; i++) {
if (mhz == channel_frequencies[i]) {
*channel = i+1;
return 1;
}
}
return -EINVAL;
}
int zd_geo_init(struct ieee80211_device *ieee, u8 regdomain)
{
struct ieee80211_geo geo;
const struct channel_range *range;
int i;
u8 channel;
dev_dbg(zd_mac_dev(zd_netdev_mac(ieee->dev)),
"regdomain %#04x\n", regdomain);
range = zd_channel_range(regdomain);
if (range->start == 0) {
dev_err(zd_mac_dev(zd_netdev_mac(ieee->dev)),
"zd1211 regdomain %#04x not supported\n",
regdomain);
return -EINVAL;
}
memset(&geo, 0, sizeof(geo));
for (i = 0, channel = range->start; channel < range->end; channel++) {
struct ieee80211_channel *chan = &geo.bg[i++];
chan->freq = channel_frequencies[channel - 1];
chan->channel = channel;
}
geo.bg_channels = i;
memcpy(geo.name, "XX ", 4);
ieee80211_set_geo(ieee, &geo);
return 0;
}