[PATCH] zd1211rw: Use softmac ERP handling functionality

This adds zd1211rw driver support for the softmac functionality I
added a while back. We now obey changes in basic rates, use short
preamble if it is available (but long if the AP says it's not),
and send self-CTS in the proper situations.

Locking fixed and improved by Ulrich Kunitz.

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

4 files changed, 286 insertions, 65 deletions

diff --git a/drivers/net/wireless/zd1211rw/zd_chip.c b/drivers/net/wireless/zd1211rw/zd_chip.c
index aa661b2b76c7..8be99ebbe1cd 100644
--- a/drivers/net/wireless/zd1211rw/zd_chip.c
+++ b/drivers/net/wireless/zd1211rw/zd_chip.c
@@ -1076,6 +1076,31 @@ static int set_mandatory_rates(struct zd_chip *chip, enum ieee80211_std std)
         return zd_iowrite32_locked(chip, rates, CR_MANDATORY_RATE_TBL);
 }
 
+int zd_chip_set_rts_cts_rate_locked(struct zd_chip *chip,
+        u8 rts_rate, int preamble)
+{
+        int rts_mod = ZD_RX_CCK;
+        u32 value = 0;
+
+        /* Modulation bit */
+        if (ZD_CS_TYPE(rts_rate) == ZD_CS_OFDM)
+                rts_mod = ZD_RX_OFDM;
+
+        dev_dbg_f(zd_chip_dev(chip), "rts_rate=%x preamble=%x\n",
+                rts_rate, preamble);
+
+        value |= rts_rate << RTSCTS_SH_RTS_RATE;
+        value |= rts_mod << RTSCTS_SH_RTS_MOD_TYPE;
+        value |= preamble << RTSCTS_SH_RTS_PMB_TYPE;
+        value |= preamble << RTSCTS_SH_CTS_PMB_TYPE;
+
+        /* We always send 11M self-CTS messages, like the vendor driver. */
+        value |= ZD_CCK_RATE_11M << RTSCTS_SH_CTS_RATE;
+        value |= ZD_RX_CCK << RTSCTS_SH_CTS_MOD_TYPE;
+
+        return zd_iowrite32_locked(chip, value, CR_RTS_CTS_RATE);
+}
+
 int zd_chip_enable_hwint(struct zd_chip *chip)
 {
         int r;
@@ -1355,17 +1380,12 @@ out:
         return r;
 }
 
-int zd_chip_set_basic_rates(struct zd_chip *chip, u16 cr_rates)
+int zd_chip_set_basic_rates_locked(struct zd_chip *chip, u16 cr_rates)
 {
-        int r;
-
-        if (cr_rates & ~(CR_RATES_80211B|CR_RATES_80211G))
-                return -EINVAL;
+        ZD_ASSERT((cr_rates & ~(CR_RATES_80211B | CR_RATES_80211G)) == 0);
+        dev_dbg_f(zd_chip_dev(chip), "%x\n", cr_rates);
 
-        mutex_lock(&chip->mutex);
-        r = zd_iowrite32_locked(chip, cr_rates, CR_BASIC_RATE_TBL);
-        mutex_unlock(&chip->mutex);
-        return r;
+        return zd_iowrite32_locked(chip, cr_rates, CR_BASIC_RATE_TBL);
 }
 
 static int ofdm_qual_db(u8 status_quality, u8 rate, unsigned int size)
diff --git a/drivers/net/wireless/zd1211rw/zd_chip.h b/drivers/net/wireless/zd1211rw/zd_chip.h
index f441cf40f74b..ca892b9a6448 100644
--- a/drivers/net/wireless/zd1211rw/zd_chip.h
+++ b/drivers/net/wireless/zd1211rw/zd_chip.h
@@ -420,6 +420,15 @@
 #define CR_MANDATORY_RATE_TBL           CTL_REG(0x0634)
 #define CR_RTS_CTS_RATE                 CTL_REG(0x0638)
 
+/* These are all bit indexes in CR_RTS_CTS_RATE, so remember to shift. */
+#define RTSCTS_SH_RTS_RATE              0
+#define RTSCTS_SH_EXP_CTS_RATE          4
+#define RTSCTS_SH_RTS_MOD_TYPE          8
+#define RTSCTS_SH_RTS_PMB_TYPE          9
+#define RTSCTS_SH_CTS_RATE              16
+#define RTSCTS_SH_CTS_MOD_TYPE          24
+#define RTSCTS_SH_CTS_PMB_TYPE          25
+
 #define CR_WEP_PROTECT                  CTL_REG(0x063C)
 #define CR_RX_THRESHOLD                 CTL_REG(0x0640)
 
@@ -794,6 +803,9 @@ void zd_chip_disable_rx(struct zd_chip *chip);
 int zd_chip_enable_hwint(struct zd_chip *chip);
 int zd_chip_disable_hwint(struct zd_chip *chip);
 
+int zd_chip_set_rts_cts_rate_locked(struct zd_chip *chip,
+        u8 rts_rate, int preamble);
+
 static inline int zd_get_encryption_type(struct zd_chip *chip, u32 *type)
 {
         return zd_ioread32(chip, CR_ENCRYPTION_TYPE, type);
@@ -809,7 +821,17 @@ static inline int zd_chip_get_basic_rates(struct zd_chip *chip, u16 *cr_rates)
         return zd_ioread16(chip, CR_BASIC_RATE_TBL, cr_rates);
 }
 
-int zd_chip_set_basic_rates(struct zd_chip *chip, u16 cr_rates);
+int zd_chip_set_basic_rates_locked(struct zd_chip *chip, u16 cr_rates);
+
+static inline int zd_chip_set_basic_rates(struct zd_chip *chip, u16 cr_rates)
+{
+        int r;
+
+        mutex_lock(&chip->mutex);
+        r = zd_chip_set_basic_rates_locked(chip, cr_rates);
+        mutex_unlock(&chip->mutex);
+        return r;
+}
 
 static inline int zd_chip_set_rx_filter(struct zd_chip *chip, u32 filter)
 {
diff --git a/drivers/net/wireless/zd1211rw/zd_mac.c b/drivers/net/wireless/zd1211rw/zd_mac.c
index e6af18304bac..2696f95b9278 100644
--- a/drivers/net/wireless/zd1211rw/zd_mac.c
+++ b/drivers/net/wireless/zd1211rw/zd_mac.c
@@ -32,6 +32,8 @@
 
 static void ieee_init(struct ieee80211_device *ieee);
 static void softmac_init(struct ieee80211softmac_device *sm);
+static void set_rts_cts_work(void *d);
+static void set_basic_rates_work(void *d);
 
 static void housekeeping_init(struct zd_mac *mac);
 static void housekeeping_enable(struct zd_mac *mac);
@@ -46,6 +48,8 @@ int zd_mac_init(struct zd_mac *mac,
         memset(mac, 0, sizeof(*mac));
         spin_lock_init(&mac->lock);
         mac->netdev = netdev;
+        INIT_WORK(&mac->set_rts_cts_work, set_rts_cts_work, mac);
+        INIT_WORK(&mac->set_basic_rates_work, set_basic_rates_work, mac);
 
         ieee_init(ieee);
         softmac_init(ieee80211_priv(netdev));
@@ -213,6 +217,13 @@ int zd_mac_stop(struct net_device *netdev)
         housekeeping_disable(mac);
         ieee80211softmac_stop(netdev);
 
+        /* Ensure no work items are running or queued from this point */
+        cancel_delayed_work(&mac->set_rts_cts_work);
+        cancel_delayed_work(&mac->set_basic_rates_work);
+        flush_workqueue(zd_workqueue);
+        mac->updating_rts_rate = 0;
+        mac->updating_basic_rates = 0;
+
         zd_chip_disable_hwint(chip);
         zd_chip_switch_radio_off(chip);
         zd_chip_disable_int(chip);
@@ -286,6 +297,186 @@ u8 zd_mac_get_regdomain(struct zd_mac *mac)
         return regdomain;
 }
 
+/* Fallback to lowest rate, if rate is unknown. */
+static u8 rate_to_zd_rate(u8 rate)
+{
+        switch (rate) {
+        case IEEE80211_CCK_RATE_2MB:
+                return ZD_CCK_RATE_2M;
+        case IEEE80211_CCK_RATE_5MB:
+                return ZD_CCK_RATE_5_5M;
+        case IEEE80211_CCK_RATE_11MB:
+                return ZD_CCK_RATE_11M;
+        case IEEE80211_OFDM_RATE_6MB:
+                return ZD_OFDM_RATE_6M;
+        case IEEE80211_OFDM_RATE_9MB:
+                return ZD_OFDM_RATE_9M;
+        case IEEE80211_OFDM_RATE_12MB:
+                return ZD_OFDM_RATE_12M;
+        case IEEE80211_OFDM_RATE_18MB:
+                return ZD_OFDM_RATE_18M;
+        case IEEE80211_OFDM_RATE_24MB:
+                return ZD_OFDM_RATE_24M;
+        case IEEE80211_OFDM_RATE_36MB:
+                return ZD_OFDM_RATE_36M;
+        case IEEE80211_OFDM_RATE_48MB:
+                return ZD_OFDM_RATE_48M;
+        case IEEE80211_OFDM_RATE_54MB:
+                return ZD_OFDM_RATE_54M;
+        }
+        return ZD_CCK_RATE_1M;
+}
+
+static u16 rate_to_cr_rate(u8 rate)
+{
+        switch (rate) {
+        case IEEE80211_CCK_RATE_2MB:
+                return CR_RATE_1M;
+        case IEEE80211_CCK_RATE_5MB:
+                return CR_RATE_5_5M;
+        case IEEE80211_CCK_RATE_11MB:
+                return CR_RATE_11M;
+        case IEEE80211_OFDM_RATE_6MB:
+                return CR_RATE_6M;
+        case IEEE80211_OFDM_RATE_9MB:
+                return CR_RATE_9M;
+        case IEEE80211_OFDM_RATE_12MB:
+                return CR_RATE_12M;
+        case IEEE80211_OFDM_RATE_18MB:
+                return CR_RATE_18M;
+        case IEEE80211_OFDM_RATE_24MB:
+                return CR_RATE_24M;
+        case IEEE80211_OFDM_RATE_36MB:
+                return CR_RATE_36M;
+        case IEEE80211_OFDM_RATE_48MB:
+                return CR_RATE_48M;
+        case IEEE80211_OFDM_RATE_54MB:
+                return CR_RATE_54M;
+        }
+        return CR_RATE_1M;
+}
+
+static void try_enable_tx(struct zd_mac *mac)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&mac->lock, flags);
+        if (mac->updating_rts_rate == 0 && mac->updating_basic_rates == 0)
+                netif_wake_queue(mac->netdev);
+        spin_unlock_irqrestore(&mac->lock, flags);
+}
+
+static void set_rts_cts_work(void *d)
+{
+        struct zd_mac *mac = d;
+        unsigned long flags;
+        u8 rts_rate;
+        unsigned int short_preamble;
+
+        mutex_lock(&mac->chip.mutex);
+
+        spin_lock_irqsave(&mac->lock, flags);
+        mac->updating_rts_rate = 0;
+        rts_rate = mac->rts_rate;
+        short_preamble = mac->short_preamble;
+        spin_unlock_irqrestore(&mac->lock, flags);
+
+        zd_chip_set_rts_cts_rate_locked(&mac->chip, rts_rate, short_preamble);
+        mutex_unlock(&mac->chip.mutex);
+
+        try_enable_tx(mac);
+}
+
+static void set_basic_rates_work(void *d)
+{
+        struct zd_mac *mac = d;
+        unsigned long flags;
+        u16 basic_rates;
+
+        mutex_lock(&mac->chip.mutex);
+
+        spin_lock_irqsave(&mac->lock, flags);
+        mac->updating_basic_rates = 0;
+        basic_rates = mac->basic_rates;
+        spin_unlock_irqrestore(&mac->lock, flags);
+
+        zd_chip_set_basic_rates_locked(&mac->chip, basic_rates);
+        mutex_unlock(&mac->chip.mutex);
+
+        try_enable_tx(mac);
+}
+
+static void bssinfo_change(struct net_device *netdev, u32 changes)
+{
+        struct zd_mac *mac = zd_netdev_mac(netdev);
+        struct ieee80211softmac_device *softmac = ieee80211_priv(netdev);
+        struct ieee80211softmac_bss_info *bssinfo = &softmac->bssinfo;
+        int need_set_rts_cts = 0;
+        int need_set_rates = 0;
+        u16 basic_rates;
+        unsigned long flags;
+
+        dev_dbg_f(zd_mac_dev(mac), "changes: %x\n", changes);
+
+        if (changes & IEEE80211SOFTMAC_BSSINFOCHG_SHORT_PREAMBLE) {
+                spin_lock_irqsave(&mac->lock, flags);
+                mac->short_preamble = bssinfo->short_preamble;
+                spin_unlock_irqrestore(&mac->lock, flags);
+                need_set_rts_cts = 1;
+        }
+
+        if (changes & IEEE80211SOFTMAC_BSSINFOCHG_RATES) {
+                /* Set RTS rate to highest available basic rate */
+                u8 rate = ieee80211softmac_highest_supported_rate(softmac,
+                        &bssinfo->supported_rates, 1);
+                rate = rate_to_zd_rate(rate);
+
+                spin_lock_irqsave(&mac->lock, flags);
+                if (rate != mac->rts_rate) {
+                        mac->rts_rate = rate;
+                        need_set_rts_cts = 1;
+                }
+                spin_unlock_irqrestore(&mac->lock, flags);
+
+                /* Set basic rates */
+                need_set_rates = 1;
+                if (bssinfo->supported_rates.count == 0) {
+                        /* Allow the device to be flexible */
+                        basic_rates = CR_RATES_80211B | CR_RATES_80211G;
+                } else {
+                        int i = 0;
+                        basic_rates = 0;
+
+                        for (i = 0; i < bssinfo->supported_rates.count; i++) {
+                                u16 rate = bssinfo->supported_rates.rates[i];
+                                if ((rate & IEEE80211_BASIC_RATE_MASK) == 0)
+                                        continue;
+
+                                rate &= ~IEEE80211_BASIC_RATE_MASK;
+                                basic_rates |= rate_to_cr_rate(rate);
+                        }
+                }
+                spin_lock_irqsave(&mac->lock, flags);
+                mac->basic_rates = basic_rates;
+                spin_unlock_irqrestore(&mac->lock, flags);
+        }
+
+        /* Schedule any changes we made above */
+
+        spin_lock_irqsave(&mac->lock, flags);
+        if (need_set_rts_cts && !mac->updating_rts_rate) {
+                mac->updating_rts_rate = 1;
+                netif_stop_queue(mac->netdev);
+                queue_work(zd_workqueue, &mac->set_rts_cts_work);
+        }
+        if (need_set_rates && !mac->updating_basic_rates) {
+                mac->updating_basic_rates = 1;
+                netif_stop_queue(mac->netdev);
+                queue_work(zd_workqueue, &mac->set_basic_rates_work);
+        }
+        spin_unlock_irqrestore(&mac->lock, flags);
+}
+
 static void set_channel(struct net_device *netdev, u8 channel)
 {
         struct zd_mac *mac = zd_netdev_mac(netdev);
@@ -346,36 +537,6 @@ static u8 zd_rate_typed(u8 zd_rate)
         return typed_rates[zd_rate & ZD_CS_RATE_MASK];
 }
 
-/* Fallback to lowest rate, if rate is unknown. */
-static u8 rate_to_zd_rate(u8 rate)
-{
-        switch (rate) {
-        case IEEE80211_CCK_RATE_2MB:
-                return ZD_CCK_RATE_2M;
-        case IEEE80211_CCK_RATE_5MB:
-                return ZD_CCK_RATE_5_5M;
-        case IEEE80211_CCK_RATE_11MB:
-                return ZD_CCK_RATE_11M;
-        case IEEE80211_OFDM_RATE_6MB:
-                return ZD_OFDM_RATE_6M;
-        case IEEE80211_OFDM_RATE_9MB:
-                return ZD_OFDM_RATE_9M;
-        case IEEE80211_OFDM_RATE_12MB:
-                return ZD_OFDM_RATE_12M;
-        case IEEE80211_OFDM_RATE_18MB:
-                return ZD_OFDM_RATE_18M;
-        case IEEE80211_OFDM_RATE_24MB:
-                return ZD_OFDM_RATE_24M;
-        case IEEE80211_OFDM_RATE_36MB:
-                return ZD_OFDM_RATE_36M;
-        case IEEE80211_OFDM_RATE_48MB:
-                return ZD_OFDM_RATE_48M;
-        case IEEE80211_OFDM_RATE_54MB:
-                return ZD_OFDM_RATE_54M;
-        }
-        return ZD_CCK_RATE_1M;
-}
-
 int zd_mac_set_mode(struct zd_mac *mac, u32 mode)
 {
         struct ieee80211_device *ieee;
@@ -550,37 +711,34 @@ static void cs_set_modulation(struct zd_mac *mac, struct zd_ctrlset *cs,
         u16 ftype = WLAN_FC_GET_TYPE(le16_to_cpu(hdr->frame_ctl));
         u8 rate, zd_rate;
         int is_mgt = (ftype == IEEE80211_FTYPE_MGMT) != 0;
+        int is_multicast = is_multicast_ether_addr(hdr->addr1);
+        int short_preamble = ieee80211softmac_short_preamble_ok(softmac,
+                is_multicast, is_mgt);
+        int flags = 0;
 
-        /* FIXME: 802.11a? short preamble? */
-        rate = ieee80211softmac_suggest_txrate(softmac,
-                is_multicast_ether_addr(hdr->addr1), is_mgt);
+        /* FIXME: 802.11a? */
+        rate = ieee80211softmac_suggest_txrate(softmac, is_multicast, is_mgt);
+
+        if (short_preamble)
+                flags |= R2M_SHORT_PREAMBLE;
 
         zd_rate = rate_to_zd_rate(rate);
-        cs->modulation = zd_rate_to_modulation(zd_rate, 0);
+        cs->modulation = zd_rate_to_modulation(zd_rate, flags);
 }
 
 static void cs_set_control(struct zd_mac *mac, struct zd_ctrlset *cs,
                            struct ieee80211_hdr_4addr *header)
 {
+        struct ieee80211softmac_device *softmac = ieee80211_priv(mac->netdev);
         unsigned int tx_length = le16_to_cpu(cs->tx_length);
         u16 fctl = le16_to_cpu(header->frame_ctl);
         u16 ftype = WLAN_FC_GET_TYPE(fctl);
         u16 stype = WLAN_FC_GET_STYPE(fctl);
 
         /*
-         * CONTROL:
-         * - start at 0x00
-         * - if fragment 0, enable bit 0
+         * CONTROL TODO:
          * - if backoff needed, enable bit 0
          * - if burst (backoff not needed) disable bit 0
-         * - if multicast, enable bit 1
-         * - if PS-POLL frame, enable bit 2
-         * - if in INDEPENDENT_BSS mode and zd1205_DestPowerSave, then enable
-         *   bit 4 (FIXME: wtf)
-         * - if frag_len > RTS threshold, set bit 5 as long if it isnt
-         *   multicast or mgt
-         * - if bit 5 is set, and we are in OFDM mode, unset bit 5 and set bit
-         *   7
          */
 
         cs->control = 0;
@@ -597,17 +755,18 @@ static void cs_set_control(struct zd_mac *mac, struct zd_ctrlset *cs,
         if (stype == IEEE80211_STYPE_PSPOLL)
                 cs->control |= ZD_CS_PS_POLL_FRAME;
 
+        /* Unicast data frames over the threshold should have RTS */
         if (!is_multicast_ether_addr(header->addr1) &&
-            ftype != IEEE80211_FTYPE_MGMT &&
-            tx_length > zd_netdev_ieee80211(mac->netdev)->rts)
-        {
-                /* FIXME: check the logic */
-                if (ZD_CS_TYPE(cs->modulation) == ZD_CS_OFDM) {
-                        /* 802.11g */
-                        cs->control |= ZD_CS_SELF_CTS;
-                } else { /* 802.11b */
-                        cs->control |= ZD_CS_RTS;
-                }
+                ftype != IEEE80211_FTYPE_MGMT &&
+                    tx_length > zd_netdev_ieee80211(mac->netdev)->rts)
+                cs->control |= ZD_CS_RTS;
+
+        /* Use CTS-to-self protection if required */
+        if (ZD_CS_TYPE(cs->modulation) == ZD_CS_OFDM &&
+                        ieee80211softmac_protection_needed(softmac)) {
+                /* FIXME: avoid sending RTS *and* self-CTS, is that correct? */
+                cs->control &= ~ZD_CS_RTS;
+                cs->control |= ZD_CS_SELF_CTS;
         }
 
         /* FIXME: Management frame? */
@@ -985,6 +1144,7 @@ static void ieee_init(struct ieee80211_device *ieee)
 static void softmac_init(struct ieee80211softmac_device *sm)
 {
         sm->set_channel = set_channel;
+        sm->bssinfo_change = bssinfo_change;
 }
 
 struct iw_statistics *zd_mac_get_wireless_stats(struct net_device *ndev)
diff --git a/drivers/net/wireless/zd1211rw/zd_mac.h b/drivers/net/wireless/zd1211rw/zd_mac.h
index 3c86578150b3..5dcfb251f02e 100644
--- a/drivers/net/wireless/zd1211rw/zd_mac.h
+++ b/drivers/net/wireless/zd1211rw/zd_mac.h
@@ -20,6 +20,7 @@
 
 #include <linux/wireless.h>
 #include <linux/kernel.h>
+#include <linux/workqueue.h>
 #include <net/ieee80211.h>
 #include <net/ieee80211softmac.h>
 
@@ -127,15 +128,33 @@ struct zd_mac {
         struct zd_chip chip;
         spinlock_t lock;
         struct net_device *netdev;
+
         /* Unlocked reading possible */
         struct iw_statistics iw_stats;
+
         struct housekeeping housekeeping;
+        struct work_struct set_rts_cts_work;
+        struct work_struct set_basic_rates_work;
+
         unsigned int stats_count;
         u8 qual_buffer[ZD_MAC_STATS_BUFFER_SIZE];
         u8 rssi_buffer[ZD_MAC_STATS_BUFFER_SIZE];
         u8 regdomain;
         u8 default_regdomain;
         u8 requested_channel;
+
+        /* A bitpattern of cr_rates */
+        u16 basic_rates;
+
+        /* A zd_rate */
+        u8 rts_rate;
+
+        /* Short preamble (used for RTS/CTS) */
+        unsigned int short_preamble:1;
+
+        /* flags to indicate update in progress */
+        unsigned int updating_rts_rate:1;
+        unsigned int updating_basic_rates:1;
 };
 
 static inline struct ieee80211_device *zd_mac_to_ieee80211(struct zd_mac *mac)