firmware/target/arm/s5l8700/kernel-s5l8700.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
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   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright © 2009 Bertrik Sikken
  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 #include "config.h"
  22 #include "system.h"
  23 #include "kernel.h"
  24
  25 /*  S5L8700 driver for the kernel timer
  26
  27     Timer B is configured as a 10 kHz timer (assuming PCLK = 48 MHz)
  28  */
  29
  30 void INT_TIMERB(void)
  31 {
  32     /* clear interrupt */
  33     TBCON = TBCON;
  34
  35     call_tick_tasks();  /* Run through the list of tick tasks */
  36 }
  37
  38 void tick_start(unsigned int interval_in_ms)
  39 {
  40     int cycles = 10 * interval_in_ms;
  41
  42     /* enable timer clock */
  43     PWRCON &= ~(1 << 4);
  44
  45     /* configure timer for 10 kHz */
  46     TBCMD = (1 << 1);   /* TB_CLR */
  47     TBPRE = 300 - 1;    /* prescaler for 48 MHz HCLK */
  48     TBCON = (0 << 13) | /* TB_INT1_EN */
  49             (1 << 12) | /* TB_INT0_EN */
  50             (0 << 11) | /* TB_START */
  51             (2 << 8) |  /* TB_CS = PCLK / 16 */
  52             (0 << 4);   /* TB_MODE_SEL = interval mode */
  53     TBDATA0 = cycles;   /* set interval period */
  54     TBCMD = (1 << 0);   /* TB_EN */
  55
  56     /* enable timer interrupt */
  57     INTMSK |= INTMSK_TIMERB;
  58 }
  59