[PATCH] ZyDAS ZD1211 USB-WLAN driver

There are 60+ USB wifi adapters available on the market based on the ZyDAS
ZD1211 chip.

Unlike the predecessor (ZD1201), ZD1211 does not have a hardware MAC, so most
data operations are coordinated by the device driver. The ZD1211 chip sits
alongside an RF transceiver which is also controlled by the driver. Our driver
currently supports 2 RF types, we know of one other available in a few marketed
products which we will be supporting soon.

Our driver also supports the newer revision of ZD1211, called ZD1211B. The
initialization and RF operations are slightly different for the new revision,
but the main difference is 802.11e support. Our driver does not support the
QoS features yet, but we think we know how to use them.

This driver is based on ZyDAS's own GPL driver available from www.zydas.com.tw.
ZyDAS engineers have been responsive and supportive of our efforts, so thumbs
up to them. Additionally, the firmware is redistributable and they have
provided device specs.

This driver has been written primarily by Ulrich Kunitz and myself. Graham
Gower, Greg KH, Remco and Bryan Rittmeyer have also contributed. The
developers of ieee80211 and softmac have made our lives so much easier- thanks!

We maintain a small info-page: http://zd1211.ath.cx/wiki/DriverRewrite

If there is enough time for review, we would like to aim for inclusion in
2.6.18. The driver works nicely as a STA, and can connect to both open and
encrypted networks (we are using software-based encryption for now). We will
work towards supporting more advanced features in the future (ad-hoc, master
mode, 802.11a, ...).

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

1 files changed, 191 insertions, 0 deletions

diff --git a/drivers/net/wireless/zd1211rw/zd_ieee80211.c b/drivers/net/wireless/zd1211rw/zd_ieee80211.c
new file mode 100644
index 000000000000..66905f7b61ff
--- /dev/null
+++ b/drivers/net/wireless/zd1211rw/zd_ieee80211.c
@@ -0,0 +1,191 @@
+/* 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},
+        [ZD_REGDOMAIN_JAPAN_ADD] = {14, 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->flags & IW_FREQ_FIXED))
+                return 0;
+
+        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;
+}