drivers/net/wireless/st/cw1200/pm.c

   1 /*
   2  * Mac80211 power management API for ST-Ericsson CW1200 drivers
   3  *
   4  * Copyright (c) 2011, ST-Ericsson
   5  * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/if_ether.h>
  14 #include "cw1200.h"
  15 #include "pm.h"
  16 #include "sta.h"
  17 #include "bh.h"
  18 #include "hwbus.h"
  19
  20 #define CW1200_BEACON_SKIPPING_MULTIPLIER 3
  21
  22 struct cw1200_udp_port_filter {
  23         struct wsm_udp_port_filter_hdr hdr;
  24         /* Up to 4 filters are allowed. */
  25         struct wsm_udp_port_filter filters[WSM_MAX_FILTER_ELEMENTS];
  26 } __packed;
  27
  28 struct cw1200_ether_type_filter {
  29         struct wsm_ether_type_filter_hdr hdr;
  30         /* Up to 4 filters are allowed. */
  31         struct wsm_ether_type_filter filters[WSM_MAX_FILTER_ELEMENTS];
  32 } __packed;
  33
  34 static struct cw1200_udp_port_filter cw1200_udp_port_filter_on = {
  35         .hdr.num = 2,
  36         .filters = {
  37                 [0] = {
  38                         .action = WSM_FILTER_ACTION_FILTER_OUT,
  39                         .type = WSM_FILTER_PORT_TYPE_DST,
  40                         .port = __cpu_to_le16(67), /* DHCP Bootps */
  41                 },
  42                 [1] = {
  43                         .action = WSM_FILTER_ACTION_FILTER_OUT,
  44                         .type = WSM_FILTER_PORT_TYPE_DST,
  45                         .port = __cpu_to_le16(68), /* DHCP Bootpc */
  46                 },
  47         }
  48 };
  49
  50 static struct wsm_udp_port_filter_hdr cw1200_udp_port_filter_off = {
  51         .num = 0,
  52 };
  53
  54 #ifndef ETH_P_WAPI
  55 #define ETH_P_WAPI     0x88B4
  56 #endif
  57
  58 static struct cw1200_ether_type_filter cw1200_ether_type_filter_on = {
  59         .hdr.num = 4,
  60         .filters = {
  61                 [0] = {
  62                         .action = WSM_FILTER_ACTION_FILTER_IN,
  63                         .type = __cpu_to_le16(ETH_P_IP),
  64                 },
  65                 [1] = {
  66                         .action = WSM_FILTER_ACTION_FILTER_IN,
  67                         .type = __cpu_to_le16(ETH_P_PAE),
  68                 },
  69                 [2] = {
  70                         .action = WSM_FILTER_ACTION_FILTER_IN,
  71                         .type = __cpu_to_le16(ETH_P_WAPI),
  72                 },
  73                 [3] = {
  74                         .action = WSM_FILTER_ACTION_FILTER_IN,
  75                         .type = __cpu_to_le16(ETH_P_ARP),
  76                 },
  77         },
  78 };
  79
  80 static struct wsm_ether_type_filter_hdr cw1200_ether_type_filter_off = {
  81         .num = 0,
  82 };
  83
  84 /* private */
  85 struct cw1200_suspend_state {
  86         unsigned long bss_loss_tmo;
  87         unsigned long join_tmo;
  88         unsigned long direct_probe;
  89         unsigned long link_id_gc;
  90         bool beacon_skipping;
  91         u8 prev_ps_mode;
  92 };
  93
  94 static void cw1200_pm_stay_awake_tmo(struct timer_list *unused)
  95 {
  96         /* XXX what's the point of this ? */
  97 }
  98
  99 int cw1200_pm_init(struct cw1200_pm_state *pm,
 100                    struct cw1200_common *priv)
 101 {
 102         spin_lock_init(&pm->lock);
 103
 104         timer_setup(&pm->stay_awake, cw1200_pm_stay_awake_tmo, 0);
 105
 106         return 0;
 107 }
 108
 109 void cw1200_pm_deinit(struct cw1200_pm_state *pm)
 110 {
 111         del_timer_sync(&pm->stay_awake);
 112 }
 113
 114 void cw1200_pm_stay_awake(struct cw1200_pm_state *pm,
 115                           unsigned long tmo)
 116 {
 117         long cur_tmo;
 118         spin_lock_bh(&pm->lock);
 119         cur_tmo = pm->stay_awake.expires - jiffies;
 120         if (!timer_pending(&pm->stay_awake) || cur_tmo < (long)tmo)
 121                 mod_timer(&pm->stay_awake, jiffies + tmo);
 122         spin_unlock_bh(&pm->lock);
 123 }
 124
 125 static long cw1200_suspend_work(struct delayed_work *work)
 126 {
 127         int ret = cancel_delayed_work(work);
 128         long tmo;
 129         if (ret > 0) {
 130                 /* Timer is pending */
 131                 tmo = work->timer.expires - jiffies;
 132                 if (tmo < 0)
 133                         tmo = 0;
 134         } else {
 135                 tmo = -1;
 136         }
 137         return tmo;
 138 }
 139
 140 static int cw1200_resume_work(struct cw1200_common *priv,
 141                                struct delayed_work *work,
 142                                unsigned long tmo)
 143 {
 144         if ((long)tmo < 0)
 145                 return 1;
 146
 147         return queue_delayed_work(priv->workqueue, work, tmo);
 148 }
 149
 150 int cw1200_can_suspend(struct cw1200_common *priv)
 151 {
 152         if (atomic_read(&priv->bh_rx)) {
 153                 wiphy_dbg(priv->hw->wiphy, "Suspend interrupted.\n");
 154                 return 0;
 155         }
 156         return 1;
 157 }
 158 EXPORT_SYMBOL_GPL(cw1200_can_suspend);
 159
 160 int cw1200_wow_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 161 {
 162         struct cw1200_common *priv = hw->priv;
 163         struct cw1200_pm_state *pm_state = &priv->pm_state;
 164         struct cw1200_suspend_state *state;
 165         int ret;
 166
 167         spin_lock_bh(&pm_state->lock);
 168         ret = timer_pending(&pm_state->stay_awake);
 169         spin_unlock_bh(&pm_state->lock);
 170         if (ret)
 171                 return -EAGAIN;
 172
 173         /* Do not suspend when datapath is not idle */
 174         if (priv->tx_queue_stats.num_queued)
 175                 return -EBUSY;
 176
 177         /* Make sure there is no configuration requests in progress. */
 178         if (!mutex_trylock(&priv->conf_mutex))
 179                 return -EBUSY;
 180
 181         /* Ensure pending operations are done.
 182          * Note also that wow_suspend must return in ~2.5sec, before
 183          * watchdog is triggered.
 184          */
 185         if (priv->channel_switch_in_progress)
 186                 goto revert1;
 187
 188         /* Do not suspend when join is pending */
 189         if (priv->join_pending)
 190                 goto revert1;
 191
 192         /* Do not suspend when scanning */
 193         if (down_trylock(&priv->scan.lock))
 194                 goto revert1;
 195
 196         /* Lock TX. */
 197         wsm_lock_tx_async(priv);
 198
 199         /* Wait to avoid possible race with bh code.
 200          * But do not wait too long...
 201          */
 202         if (wait_event_timeout(priv->bh_evt_wq,
 203                                !priv->hw_bufs_used, HZ / 10) <= 0)
 204                 goto revert2;
 205
 206         /* Set UDP filter */
 207         wsm_set_udp_port_filter(priv, &cw1200_udp_port_filter_on.hdr);
 208
 209         /* Set ethernet frame type filter */
 210         wsm_set_ether_type_filter(priv, &cw1200_ether_type_filter_on.hdr);
 211
 212         /* Allocate state */
 213         state = kzalloc(sizeof(struct cw1200_suspend_state), GFP_KERNEL);
 214         if (!state)
 215                 goto revert3;
 216
 217         /* Change to legacy PS while going to suspend */
 218         if (!priv->vif->p2p &&
 219             priv->join_status == CW1200_JOIN_STATUS_STA &&
 220             priv->powersave_mode.mode != WSM_PSM_PS) {
 221                 state->prev_ps_mode = priv->powersave_mode.mode;
 222                 priv->powersave_mode.mode = WSM_PSM_PS;
 223                 cw1200_set_pm(priv, &priv->powersave_mode);
 224                 if (wait_event_interruptible_timeout(priv->ps_mode_switch_done,
 225                                                      !priv->ps_mode_switch_in_progress, 1*HZ) <= 0) {
 226                         goto revert4;
 227                 }
 228         }
 229
 230         /* Store delayed work states. */
 231         state->bss_loss_tmo =
 232                 cw1200_suspend_work(&priv->bss_loss_work);
 233         state->join_tmo =
 234                 cw1200_suspend_work(&priv->join_timeout);
 235         state->direct_probe =
 236                 cw1200_suspend_work(&priv->scan.probe_work);
 237         state->link_id_gc =
 238                 cw1200_suspend_work(&priv->link_id_gc_work);
 239
 240         cancel_delayed_work_sync(&priv->clear_recent_scan_work);
 241         atomic_set(&priv->recent_scan, 0);
 242
 243         /* Enable beacon skipping */
 244         if (priv->join_status == CW1200_JOIN_STATUS_STA &&
 245             priv->join_dtim_period &&
 246             !priv->has_multicast_subscription) {
 247                 state->beacon_skipping = true;
 248                 wsm_set_beacon_wakeup_period(priv,
 249                                              priv->join_dtim_period,
 250                                              CW1200_BEACON_SKIPPING_MULTIPLIER * priv->join_dtim_period);
 251         }
 252
 253         /* Stop serving thread */
 254         if (cw1200_bh_suspend(priv))
 255                 goto revert5;
 256
 257         ret = timer_pending(&priv->mcast_timeout);
 258         if (ret)
 259                 goto revert6;
 260
 261         /* Store suspend state */
 262         pm_state->suspend_state = state;
 263
 264         /* Enable IRQ wake */
 265         ret = priv->hwbus_ops->power_mgmt(priv->hwbus_priv, true);
 266         if (ret) {
 267                 wiphy_err(priv->hw->wiphy,
 268                           "PM request failed: %d. WoW is disabled.\n", ret);
 269                 cw1200_wow_resume(hw);
 270                 return -EBUSY;
 271         }
 272
 273         /* Force resume if event is coming from the device. */
 274         if (atomic_read(&priv->bh_rx)) {
 275                 cw1200_wow_resume(hw);
 276                 return -EAGAIN;
 277         }
 278
 279         return 0;
 280
 281 revert6:
 282         WARN_ON(cw1200_bh_resume(priv));
 283 revert5:
 284         cw1200_resume_work(priv, &priv->bss_loss_work,
 285                            state->bss_loss_tmo);
 286         cw1200_resume_work(priv, &priv->join_timeout,
 287                            state->join_tmo);
 288         cw1200_resume_work(priv, &priv->scan.probe_work,
 289                            state->direct_probe);
 290         cw1200_resume_work(priv, &priv->link_id_gc_work,
 291                            state->link_id_gc);
 292 revert4:
 293         kfree(state);
 294 revert3:
 295         wsm_set_udp_port_filter(priv, &cw1200_udp_port_filter_off);
 296         wsm_set_ether_type_filter(priv, &cw1200_ether_type_filter_off);
 297 revert2:
 298         wsm_unlock_tx(priv);
 299         up(&priv->scan.lock);
 300 revert1:
 301         mutex_unlock(&priv->conf_mutex);
 302         return -EBUSY;
 303 }
 304
 305 int cw1200_wow_resume(struct ieee80211_hw *hw)
 306 {
 307         struct cw1200_common *priv = hw->priv;
 308         struct cw1200_pm_state *pm_state = &priv->pm_state;
 309         struct cw1200_suspend_state *state;
 310
 311         state = pm_state->suspend_state;
 312         pm_state->suspend_state = NULL;
 313
 314         /* Disable IRQ wake */
 315         priv->hwbus_ops->power_mgmt(priv->hwbus_priv, false);
 316
 317         /* Scan.lock must be released before BH is resumed other way
 318          * in case when BSS_LOST command arrived the processing of the
 319          * command will be delayed.
 320          */
 321         up(&priv->scan.lock);
 322
 323         /* Resume BH thread */
 324         WARN_ON(cw1200_bh_resume(priv));
 325
 326         /* Restores previous PS mode */
 327         if (!priv->vif->p2p && priv->join_status == CW1200_JOIN_STATUS_STA) {
 328                 priv->powersave_mode.mode = state->prev_ps_mode;
 329                 cw1200_set_pm(priv, &priv->powersave_mode);
 330         }
 331
 332         if (state->beacon_skipping) {
 333                 wsm_set_beacon_wakeup_period(priv, priv->beacon_int *
 334                                              priv->join_dtim_period >
 335                                              MAX_BEACON_SKIP_TIME_MS ? 1 :
 336                                              priv->join_dtim_period, 0);
 337                 state->beacon_skipping = false;
 338         }
 339
 340         /* Resume delayed work */
 341         cw1200_resume_work(priv, &priv->bss_loss_work,
 342                            state->bss_loss_tmo);
 343         cw1200_resume_work(priv, &priv->join_timeout,
 344                            state->join_tmo);
 345         cw1200_resume_work(priv, &priv->scan.probe_work,
 346                            state->direct_probe);
 347         cw1200_resume_work(priv, &priv->link_id_gc_work,
 348                            state->link_id_gc);
 349
 350         /* Remove UDP port filter */
 351         wsm_set_udp_port_filter(priv, &cw1200_udp_port_filter_off);
 352
 353         /* Remove ethernet frame type filter */
 354         wsm_set_ether_type_filter(priv, &cw1200_ether_type_filter_off);
 355
 356         /* Unlock datapath */
 357         wsm_unlock_tx(priv);
 358
 359         /* Unlock configuration mutex */
 360         mutex_unlock(&priv->conf_mutex);
 361
 362         /* Free memory */
 363         kfree(state);
 364
 365         return 0;
 366 }