target/linux/ubicom32/files/arch/ubicom32/crypto/crypto_ubicom32.c

   1 /*
   2  * arch/ubicom32/crypto/crypto_ubicom32.c
   3  *   Generic code to support ubicom32 hardware crypto accelerator
   4  *
   5  * (C) Copyright 2009, Ubicom, Inc.
   6  *
   7  * This file is part of the Ubicom32 Linux Kernel Port.
   8  *
   9  * The Ubicom32 Linux Kernel Port is free software: you can redistribute
  10  * it and/or modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation, either version 2 of the
  12  * License, or (at your option) any later version.
  13  *
  14  * The Ubicom32 Linux Kernel Port is distributed in the hope that it
  15  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  16  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  * the GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with the Ubicom32 Linux Kernel Port.  If not,
  21  * see <http://www.gnu.org/licenses/>.
  22  *
  23  * Ubicom32 implementation derived from (with many thanks):
  24  *   arch/m68knommu
  25  *   arch/blackfin
  26  *   arch/parisc
  27  */
  28 #include "crypto_ubicom32.h"
  29
  30 spinlock_t crypto_ubicom32_lock;
  31 bool crypto_ubicom32_inited = false;
  32 volatile bool crypto_ubicom32_on = false;
  33 volatile unsigned long crypto_ubicom32_last_use;
  34
  35 struct timer_list crypto_ubicom32_ps_timer;
  36 void crypto_ubicom32_ps_check(unsigned long data)
  37 {
  38         unsigned long idle_time = msecs_to_jiffies(HW_CRYPTO_PS_MAX_IDLE_MS);
  39
  40         BUG_ON(!crypto_ubicom32_on);
  41
  42         if (((jiffies - crypto_ubicom32_last_use) > idle_time) && spin_trylock_bh(&crypto_ubicom32_lock)) {
  43                 hw_crypto_turn_off();
  44                 spin_unlock_bh(&crypto_ubicom32_lock);
  45                 return;
  46         }
  47
  48         /* keep monitoring */
  49         hw_crypto_ps_start();
  50 }