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(unsigned long arg)
  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         setup_timer(&pm->stay_awake, cw1200_pm_stay_awake_tmo,
 105                     (unsigned long)pm);
 106
 107         return 0;
 108 }
 109
 110 void cw1200_pm_deinit(struct cw1200_pm_state *pm)
 111 {
 112         del_timer_sync(&pm->stay_awake);
 113 }
 114
 115 void cw1200_pm_stay_awake(struct cw1200_pm_state *pm,
 116                           unsigned long tmo)
 117 {
 118         long cur_tmo;
 119         spin_lock_bh(&pm->lock);
 120         cur_tmo = pm->stay_awake.expires - jiffies;
 121         if (!timer_pending(&pm->stay_awake) || cur_tmo < (long)tmo)
 122                 mod_timer(&pm->stay_awake, jiffies + tmo);
 123         spin_unlock_bh(&pm->lock);
 124 }
 125
 126 static long cw1200_suspend_work(struct delayed_work *work)
 127 {
 128         int ret = cancel_delayed_work(work);
 129         long tmo;
 130         if (ret > 0) {
 131                 /* Timer is pending */
 132                 tmo = work->timer.expires - jiffies;
 133                 if (tmo < 0)
 134                         tmo = 0;
 135         } else {
 136                 tmo = -1;
 137         }
 138         return tmo;
 139 }
 140
 141 static int cw1200_resume_work(struct cw1200_common *priv,
 142                                struct delayed_work *work,
 143                                unsigned long tmo)
 144 {
 145         if ((long)tmo < 0)
 146                 return 1;
 147
 148         return queue_delayed_work(priv->workqueue, work, tmo);
 149 }
 150
 151 int cw1200_can_suspend(struct cw1200_common *priv)
 152 {
 153         if (atomic_read(&priv->bh_rx)) {
 154                 wiphy_dbg(priv->hw->wiphy, "Suspend interrupted.\n");
 155                 return 0;
 156         }
 157         return 1;
 158 }
 159 EXPORT_SYMBOL_GPL(cw1200_can_suspend);
 160
 161 int cw1200_wow_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 162 {
 163         struct cw1200_common *priv = hw->priv;
 164         struct cw1200_pm_state *pm_state = &priv->pm_state;
 165         struct cw1200_suspend_state *state;
 166         int ret;
 167
 168         spin_lock_bh(&pm_state->lock);
 169         ret = timer_pending(&pm_state->stay_awake);
 170         spin_unlock_bh(&pm_state->lock);
 171         if (ret)
 172                 return -EAGAIN;
 173
 174         /* Do not suspend when datapath is not idle */
 175         if (priv->tx_queue_stats.num_queued)
 176                 return -EBUSY;
 177
 178         /* Make sure there is no configuration requests in progress. */
 179         if (!mutex_trylock(&priv->conf_mutex))
 180                 return -EBUSY;
 181
 182         /* Ensure pending operations are done.
 183          * Note also that wow_suspend must return in ~2.5sec, before
 184          * watchdog is triggered.
 185          */
 186         if (priv->channel_switch_in_progress)
 187                 goto revert1;
 188
 189         /* Do not suspend when join is pending */
 190         if (priv->join_pending)
 191                 goto revert1;
 192
 193         /* Do not suspend when scanning */
 194         if (down_trylock(&priv->scan.lock))
 195                 goto revert1;
 196
 197         /* Lock TX. */
 198         wsm_lock_tx_async(priv);
 199
 200         /* Wait to avoid possible race with bh code.
 201          * But do not wait too long...
 202          */
 203         if (wait_event_timeout(priv->bh_evt_wq,
 204                                !priv->hw_bufs_used, HZ / 10) <= 0)
 205                 goto revert2;
 206
 207         /* Set UDP filter */
 208         wsm_set_udp_port_filter(priv, &cw1200_udp_port_filter_on.hdr);
 209
 210         /* Set ethernet frame type filter */
 211         wsm_set_ether_type_filter(priv, &cw1200_ether_type_filter_on.hdr);
 212
 213         /* Allocate state */
 214         state = kzalloc(sizeof(struct cw1200_suspend_state), GFP_KERNEL);
 215         if (!state)
 216                 goto revert3;
 217
 218         /* Change to legacy PS while going to suspend */
 219         if (!priv->vif->p2p &&
 220             priv->join_status == CW1200_JOIN_STATUS_STA &&
 221             priv->powersave_mode.mode != WSM_PSM_PS) {
 222                 state->prev_ps_mode = priv->powersave_mode.mode;
 223                 priv->powersave_mode.mode = WSM_PSM_PS;
 224                 cw1200_set_pm(priv, &priv->powersave_mode);
 225                 if (wait_event_interruptible_timeout(priv->ps_mode_switch_done,
 226                                                      !priv->ps_mode_switch_in_progress, 1*HZ) <= 0) {
 227                         goto revert4;
 228                 }
 229         }
 230
 231         /* Store delayed work states. */
 232         state->bss_loss_tmo =
 233                 cw1200_suspend_work(&priv->bss_loss_work);
 234         state->join_tmo =
 235                 cw1200_suspend_work(&priv->join_timeout);
 236         state->direct_probe =
 237                 cw1200_suspend_work(&priv->scan.probe_work);
 238         state->link_id_gc =
 239                 cw1200_suspend_work(&priv->link_id_gc_work);
 240
 241         cancel_delayed_work_sync(&priv->clear_recent_scan_work);
 242         atomic_set(&priv->recent_scan, 0);
 243
 244         /* Enable beacon skipping */
 245         if (priv->join_status == CW1200_JOIN_STATUS_STA &&
 246             priv->join_dtim_period &&
 247             !priv->has_multicast_subscription) {
 248                 state->beacon_skipping = true;
 249                 wsm_set_beacon_wakeup_period(priv,
 250                                              priv->join_dtim_period,
 251                                              CW1200_BEACON_SKIPPING_MULTIPLIER * priv->join_dtim_period);
 252         }
 253
 254         /* Stop serving thread */
 255         if (cw1200_bh_suspend(priv))
 256                 goto revert5;
 257
 258         ret = timer_pending(&priv->mcast_timeout);
 259         if (ret)
 260                 goto revert6;
 261
 262         /* Store suspend state */
 263         pm_state->suspend_state = state;
 264
 265         /* Enable IRQ wake */
 266         ret = priv->hwbus_ops->power_mgmt(priv->hwbus_priv, true);
 267         if (ret) {
 268                 wiphy_err(priv->hw->wiphy,
 269                           "PM request failed: %d. WoW is disabled.\n", ret);
 270                 cw1200_wow_resume(hw);
 271                 return -EBUSY;
 272         }
 273
 274         /* Force resume if event is coming from the device. */
 275         if (atomic_read(&priv->bh_rx)) {
 276                 cw1200_wow_resume(hw);
 277                 return -EAGAIN;
 278         }
 279
 280         return 0;
 281
 282 revert6:
 283         WARN_ON(cw1200_bh_resume(priv));
 284 revert5:
 285         cw1200_resume_work(priv, &priv->bss_loss_work,
 286                            state->bss_loss_tmo);
 287         cw1200_resume_work(priv, &priv->join_timeout,
 288                            state->join_tmo);
 289         cw1200_resume_work(priv, &priv->scan.probe_work,
 290                            state->direct_probe);
 291         cw1200_resume_work(priv, &priv->link_id_gc_work,
 292                            state->link_id_gc);
 293 revert4:
 294         kfree(state);
 295 revert3:
 296         wsm_set_udp_port_filter(priv, &cw1200_udp_port_filter_off);
 297         wsm_set_ether_type_filter(priv, &cw1200_ether_type_filter_off);
 298 revert2:
 299         wsm_unlock_tx(priv);
 300         up(&priv->scan.lock);
 301 revert1:
 302         mutex_unlock(&priv->conf_mutex);
 303         return -EBUSY;
 304 }
 305
 306 int cw1200_wow_resume(struct ieee80211_hw *hw)
 307 {
 308         struct cw1200_common *priv = hw->priv;
 309         struct cw1200_pm_state *pm_state = &priv->pm_state;
 310         struct cw1200_suspend_state *state;
 311
 312         state = pm_state->suspend_state;
 313         pm_state->suspend_state = NULL;
 314
 315         /* Disable IRQ wake */
 316         priv->hwbus_ops->power_mgmt(priv->hwbus_priv, false);
 317
 318         /* Scan.lock must be released before BH is resumed other way
 319          * in case when BSS_LOST command arrived the processing of the
 320          * command will be delayed.
 321          */
 322         up(&priv->scan.lock);
 323
 324         /* Resume BH thread */
 325         WARN_ON(cw1200_bh_resume(priv));
 326
 327         /* Restores previous PS mode */
 328         if (!priv->vif->p2p && priv->join_status == CW1200_JOIN_STATUS_STA) {
 329                 priv->powersave_mode.mode = state->prev_ps_mode;
 330                 cw1200_set_pm(priv, &priv->powersave_mode);
 331         }
 332
 333         if (state->beacon_skipping) {
 334                 wsm_set_beacon_wakeup_period(priv, priv->beacon_int *
 335                                              priv->join_dtim_period >
 336                                              MAX_BEACON_SKIP_TIME_MS ? 1 :
 337                                              priv->join_dtim_period, 0);
 338                 state->beacon_skipping = false;
 339         }
 340
 341         /* Resume delayed work */
 342         cw1200_resume_work(priv, &priv->bss_loss_work,
 343                            state->bss_loss_tmo);
 344         cw1200_resume_work(priv, &priv->join_timeout,
 345                            state->join_tmo);
 346         cw1200_resume_work(priv, &priv->scan.probe_work,
 347                            state->direct_probe);
 348         cw1200_resume_work(priv, &priv->link_id_gc_work,
 349                            state->link_id_gc);
 350
 351         /* Remove UDP port filter */
 352         wsm_set_udp_port_filter(priv, &cw1200_udp_port_filter_off);
 353
 354         /* Remove ethernet frame type filter */
 355         wsm_set_ether_type_filter(priv, &cw1200_ether_type_filter_off);
 356
 357         /* Unlock datapath */
 358         wsm_unlock_tx(priv);
 359
 360         /* Unlock configuration mutex */
 361         mutex_unlock(&priv->conf_mutex);
 362
 363         /* Free memory */
 364         kfree(state);
 365
 366         return 0;
 367 }