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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Mac80211 power management API for ST-Ericsson CW1200 drivers
   4  *
   5  * Copyright (c) 2011, ST-Ericsson
   6  * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/if_ether.h>
  11 #include "cw1200.h"
  12 #include "pm.h"
  13 #include "sta.h"
  14 #include "bh.h"
  15 #include "hwbus.h"
  16
  17 #define CW1200_BEACON_SKIPPING_MULTIPLIER 3
  18
  19 struct cw1200_udp_port_filter {
  20         struct wsm_udp_port_filter_hdr hdr;
  21         /* Up to 4 filters are allowed. */
  22         struct wsm_udp_port_filter filters[WSM_MAX_FILTER_ELEMENTS];
  23 } __packed;
  24
  25 struct cw1200_ether_type_filter {
  26         struct wsm_ether_type_filter_hdr hdr;
  27         /* Up to 4 filters are allowed. */
  28         struct wsm_ether_type_filter filters[WSM_MAX_FILTER_ELEMENTS];
  29 } __packed;
  30
  31 static struct cw1200_udp_port_filter cw1200_udp_port_filter_on = {
  32         .hdr.num = 2,
  33         .filters = {
  34                 [0] = {
  35                         .action = WSM_FILTER_ACTION_FILTER_OUT,
  36                         .type = WSM_FILTER_PORT_TYPE_DST,
  37                         .port = __cpu_to_le16(67), /* DHCP Bootps */
  38                 },
  39                 [1] = {
  40                         .action = WSM_FILTER_ACTION_FILTER_OUT,
  41                         .type = WSM_FILTER_PORT_TYPE_DST,
  42                         .port = __cpu_to_le16(68), /* DHCP Bootpc */
  43                 },
  44         }
  45 };
  46
  47 static struct wsm_udp_port_filter_hdr cw1200_udp_port_filter_off = {
  48         .num = 0,
  49 };
  50
  51 #ifndef ETH_P_WAPI
  52 #define ETH_P_WAPI     0x88B4
  53 #endif
  54
  55 static struct cw1200_ether_type_filter cw1200_ether_type_filter_on = {
  56         .hdr.num = 4,
  57         .filters = {
  58                 [0] = {
  59                         .action = WSM_FILTER_ACTION_FILTER_IN,
  60                         .type = __cpu_to_le16(ETH_P_IP),
  61                 },
  62                 [1] = {
  63                         .action = WSM_FILTER_ACTION_FILTER_IN,
  64                         .type = __cpu_to_le16(ETH_P_PAE),
  65                 },
  66                 [2] = {
  67                         .action = WSM_FILTER_ACTION_FILTER_IN,
  68                         .type = __cpu_to_le16(ETH_P_WAPI),
  69                 },
  70                 [3] = {
  71                         .action = WSM_FILTER_ACTION_FILTER_IN,
  72                         .type = __cpu_to_le16(ETH_P_ARP),
  73                 },
  74         },
  75 };
  76
  77 static struct wsm_ether_type_filter_hdr cw1200_ether_type_filter_off = {
  78         .num = 0,
  79 };
  80
  81 /* private */
  82 struct cw1200_suspend_state {
  83         unsigned long bss_loss_tmo;
  84         unsigned long join_tmo;
  85         unsigned long direct_probe;
  86         unsigned long link_id_gc;
  87         bool beacon_skipping;
  88         u8 prev_ps_mode;
  89 };
  90
  91 static void cw1200_pm_stay_awake_tmo(struct timer_list *unused)
  92 {
  93         /* XXX what's the point of this ? */
  94 }
  95
  96 int cw1200_pm_init(struct cw1200_pm_state *pm,
  97                    struct cw1200_common *priv)
  98 {
  99         spin_lock_init(&pm->lock);
 100
 101         timer_setup(&pm->stay_awake, cw1200_pm_stay_awake_tmo, 0);
 102
 103         return 0;
 104 }
 105
 106 void cw1200_pm_deinit(struct cw1200_pm_state *pm)
 107 {
 108         del_timer_sync(&pm->stay_awake);
 109 }
 110
 111 void cw1200_pm_stay_awake(struct cw1200_pm_state *pm,
 112                           unsigned long tmo)
 113 {
 114         long cur_tmo;
 115         spin_lock_bh(&pm->lock);
 116         cur_tmo = pm->stay_awake.expires - jiffies;
 117         if (!timer_pending(&pm->stay_awake) || cur_tmo < (long)tmo)
 118                 mod_timer(&pm->stay_awake, jiffies + tmo);
 119         spin_unlock_bh(&pm->lock);
 120 }
 121
 122 static long cw1200_suspend_work(struct delayed_work *work)
 123 {
 124         int ret = cancel_delayed_work(work);
 125         long tmo;
 126         if (ret > 0) {
 127                 /* Timer is pending */
 128                 tmo = work->timer.expires - jiffies;
 129                 if (tmo < 0)
 130                         tmo = 0;
 131         } else {
 132                 tmo = -1;
 133         }
 134         return tmo;
 135 }
 136
 137 static int cw1200_resume_work(struct cw1200_common *priv,
 138                                struct delayed_work *work,
 139                                unsigned long tmo)
 140 {
 141         if ((long)tmo < 0)
 142                 return 1;
 143
 144         return queue_delayed_work(priv->workqueue, work, tmo);
 145 }
 146
 147 int cw1200_can_suspend(struct cw1200_common *priv)
 148 {
 149         if (atomic_read(&priv->bh_rx)) {
 150                 wiphy_dbg(priv->hw->wiphy, "Suspend interrupted.\n");
 151                 return 0;
 152         }
 153         return 1;
 154 }
 155 EXPORT_SYMBOL_GPL(cw1200_can_suspend);
 156
 157 int cw1200_wow_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 158 {
 159         struct cw1200_common *priv = hw->priv;
 160         struct cw1200_pm_state *pm_state = &priv->pm_state;
 161         struct cw1200_suspend_state *state;
 162         int ret;
 163
 164         spin_lock_bh(&pm_state->lock);
 165         ret = timer_pending(&pm_state->stay_awake);
 166         spin_unlock_bh(&pm_state->lock);
 167         if (ret)
 168                 return -EAGAIN;
 169
 170         /* Do not suspend when datapath is not idle */
 171         if (priv->tx_queue_stats.num_queued)
 172                 return -EBUSY;
 173
 174         /* Make sure there is no configuration requests in progress. */
 175         if (!mutex_trylock(&priv->conf_mutex))
 176                 return -EBUSY;
 177
 178         /* Ensure pending operations are done.
 179          * Note also that wow_suspend must return in ~2.5sec, before
 180          * watchdog is triggered.
 181          */
 182         if (priv->channel_switch_in_progress)
 183                 goto revert1;
 184
 185         /* Do not suspend when join is pending */
 186         if (priv->join_pending)
 187                 goto revert1;
 188
 189         /* Do not suspend when scanning */
 190         if (down_trylock(&priv->scan.lock))
 191                 goto revert1;
 192
 193         /* Lock TX. */
 194         wsm_lock_tx_async(priv);
 195
 196         /* Wait to avoid possible race with bh code.
 197          * But do not wait too long...
 198          */
 199         if (wait_event_timeout(priv->bh_evt_wq,
 200                                !priv->hw_bufs_used, HZ / 10) <= 0)
 201                 goto revert2;
 202
 203         /* Set UDP filter */
 204         wsm_set_udp_port_filter(priv, &cw1200_udp_port_filter_on.hdr);
 205
 206         /* Set ethernet frame type filter */
 207         wsm_set_ether_type_filter(priv, &cw1200_ether_type_filter_on.hdr);
 208
 209         /* Allocate state */
 210         state = kzalloc(sizeof(struct cw1200_suspend_state), GFP_KERNEL);
 211         if (!state)
 212                 goto revert3;
 213
 214         /* Change to legacy PS while going to suspend */
 215         if (!priv->vif->p2p &&
 216             priv->join_status == CW1200_JOIN_STATUS_STA &&
 217             priv->powersave_mode.mode != WSM_PSM_PS) {
 218                 state->prev_ps_mode = priv->powersave_mode.mode;
 219                 priv->powersave_mode.mode = WSM_PSM_PS;
 220                 cw1200_set_pm(priv, &priv->powersave_mode);
 221                 if (wait_event_interruptible_timeout(priv->ps_mode_switch_done,
 222                                                      !priv->ps_mode_switch_in_progress, 1*HZ) <= 0) {
 223                         goto revert4;
 224                 }
 225         }
 226
 227         /* Store delayed work states. */
 228         state->bss_loss_tmo =
 229                 cw1200_suspend_work(&priv->bss_loss_work);
 230         state->join_tmo =
 231                 cw1200_suspend_work(&priv->join_timeout);
 232         state->direct_probe =
 233                 cw1200_suspend_work(&priv->scan.probe_work);
 234         state->link_id_gc =
 235                 cw1200_suspend_work(&priv->link_id_gc_work);
 236
 237         cancel_delayed_work_sync(&priv->clear_recent_scan_work);
 238         atomic_set(&priv->recent_scan, 0);
 239
 240         /* Enable beacon skipping */
 241         if (priv->join_status == CW1200_JOIN_STATUS_STA &&
 242             priv->join_dtim_period &&
 243             !priv->has_multicast_subscription) {
 244                 state->beacon_skipping = true;
 245                 wsm_set_beacon_wakeup_period(priv,
 246                                              priv->join_dtim_period,
 247                                              CW1200_BEACON_SKIPPING_MULTIPLIER * priv->join_dtim_period);
 248         }
 249
 250         /* Stop serving thread */
 251         if (cw1200_bh_suspend(priv))
 252                 goto revert5;
 253
 254         ret = timer_pending(&priv->mcast_timeout);
 255         if (ret)
 256                 goto revert6;
 257
 258         /* Store suspend state */
 259         pm_state->suspend_state = state;
 260
 261         /* Enable IRQ wake */
 262         ret = priv->hwbus_ops->power_mgmt(priv->hwbus_priv, true);
 263         if (ret) {
 264                 wiphy_err(priv->hw->wiphy,
 265                           "PM request failed: %d. WoW is disabled.\n", ret);
 266                 cw1200_wow_resume(hw);
 267                 return -EBUSY;
 268         }
 269
 270         /* Force resume if event is coming from the device. */
 271         if (atomic_read(&priv->bh_rx)) {
 272                 cw1200_wow_resume(hw);
 273                 return -EAGAIN;
 274         }
 275
 276         return 0;
 277
 278 revert6:
 279         WARN_ON(cw1200_bh_resume(priv));
 280 revert5:
 281         cw1200_resume_work(priv, &priv->bss_loss_work,
 282                            state->bss_loss_tmo);
 283         cw1200_resume_work(priv, &priv->join_timeout,
 284                            state->join_tmo);
 285         cw1200_resume_work(priv, &priv->scan.probe_work,
 286                            state->direct_probe);
 287         cw1200_resume_work(priv, &priv->link_id_gc_work,
 288                            state->link_id_gc);
 289 revert4:
 290         kfree(state);
 291 revert3:
 292         wsm_set_udp_port_filter(priv, &cw1200_udp_port_filter_off);
 293         wsm_set_ether_type_filter(priv, &cw1200_ether_type_filter_off);
 294 revert2:
 295         wsm_unlock_tx(priv);
 296         up(&priv->scan.lock);
 297 revert1:
 298         mutex_unlock(&priv->conf_mutex);
 299         return -EBUSY;
 300 }
 301
 302 int cw1200_wow_resume(struct ieee80211_hw *hw)
 303 {
 304         struct cw1200_common *priv = hw->priv;
 305         struct cw1200_pm_state *pm_state = &priv->pm_state;
 306         struct cw1200_suspend_state *state;
 307
 308         state = pm_state->suspend_state;
 309         pm_state->suspend_state = NULL;
 310
 311         /* Disable IRQ wake */
 312         priv->hwbus_ops->power_mgmt(priv->hwbus_priv, false);
 313
 314         /* Scan.lock must be released before BH is resumed other way
 315          * in case when BSS_LOST command arrived the processing of the
 316          * command will be delayed.
 317          */
 318         up(&priv->scan.lock);
 319
 320         /* Resume BH thread */
 321         WARN_ON(cw1200_bh_resume(priv));
 322
 323         /* Restores previous PS mode */
 324         if (!priv->vif->p2p && priv->join_status == CW1200_JOIN_STATUS_STA) {
 325                 priv->powersave_mode.mode = state->prev_ps_mode;
 326                 cw1200_set_pm(priv, &priv->powersave_mode);
 327         }
 328
 329         if (state->beacon_skipping) {
 330                 wsm_set_beacon_wakeup_period(priv, priv->beacon_int *
 331                                              priv->join_dtim_period >
 332                                              MAX_BEACON_SKIP_TIME_MS ? 1 :
 333                                              priv->join_dtim_period, 0);
 334                 state->beacon_skipping = false;
 335         }
 336
 337         /* Resume delayed work */
 338         cw1200_resume_work(priv, &priv->bss_loss_work,
 339                            state->bss_loss_tmo);
 340         cw1200_resume_work(priv, &priv->join_timeout,
 341                            state->join_tmo);
 342         cw1200_resume_work(priv, &priv->scan.probe_work,
 343                            state->direct_probe);
 344         cw1200_resume_work(priv, &priv->link_id_gc_work,
 345                            state->link_id_gc);
 346
 347         /* Remove UDP port filter */
 348         wsm_set_udp_port_filter(priv, &cw1200_udp_port_filter_off);
 349
 350         /* Remove ethernet frame type filter */
 351         wsm_set_ether_type_filter(priv, &cw1200_ether_type_filter_off);
 352
 353         /* Unlock datapath */
 354         wsm_unlock_tx(priv);
 355
 356         /* Unlock configuration mutex */
 357         mutex_unlock(&priv->conf_mutex);
 358
 359         /* Free memory */
 360         kfree(state);
 361
 362         return 0;
 363 }