firmware/target/mips/ingenic_jz47xx/kernel-jz4740.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2008 by Maurus Cuelenaere
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "kernel.h"
  25 #include "jz4740.h"
  26
  27 void tick_start(unsigned int interval_in_ms)
  28 {
  29     unsigned int latch;
  30
  31     __cpm_start_tcu();
  32
  33     __tcu_stop_counter(0);
  34     __tcu_disable_pwm_output(0);
  35
  36     __tcu_mask_half_match_irq(0);
  37     __tcu_unmask_full_match_irq(0);
  38
  39     __tcu_select_extalclk(0);
  40     __tcu_select_clk_div4(0);
  41
  42     /* 12Mhz / 4 = 3Mhz */
  43     latch = interval_in_ms*1000 * 3;
  44
  45     REG_TCU_TCNT(0) = 0;
  46     REG_TCU_TDFR(0) = latch;
  47     REG_TCU_TDHR(0) = latch;
  48
  49     __tcu_clear_full_match_flag(0);
  50     __tcu_start_counter(0);
  51
  52     system_enable_irq(IRQ_TCU0);
  53 }
  54
  55 /* Interrupt handler */
  56 void TCU0(void)
  57 {
  58     __tcu_clear_full_match_flag(0);
  59
  60     /* Run through the list of tick tasks */
  61     call_tick_tasks();
  62 }