LXR linux/arch/v850/kernel/v850e_timer

   1/*
   2 * include/asm-v850/v850e_timer_d.c -- `Timer D' component often used
   3 *      with V850E CPUs
   4 *
   5 *  Copyright (C) 2001,02,03  NEC Electronics Corporation
   6 *  Copyright (C) 2001,02,03  Miles Bader <miles@gnu.org>
   7 *
   8 * This file is subject to the terms and conditions of the GNU General
   9 * Public License.  See the file COPYING in the main directory of this
  10 * archive for more details.
  11 *
  12 * Written by Miles Bader <miles@gnu.org>
  13 */
  14
  15#include <linux/kernel.h>
  16
  17#include <asm/v850e_utils.h>
  18#include <asm/v850e_timer_d.h>
  19
  20/* Start interval timer TIMER (0-3).  The timer will issue the
  21   corresponding INTCMD interrupt RATE times per second.
  22   This function does not enable the interrupt.  */
  23void v850e_timer_d_configure (unsigned timer, unsigned rate)
  24{
  25        unsigned divlog2, count;
  26
  27        /* Calculate params for timer.  */
  28        if (! calc_counter_params (
  29                    V850E_TIMER_D_BASE_FREQ, rate,
  30                    V850E_TIMER_D_TMCD_CS_MIN, V850E_TIMER_D_TMCD_CS_MAX, 16,
  31                    &divlog2, &count))
  32                printk (KERN_WARNING
  33                        "Cannot find interval timer %d setting suitable"
  34                        " for rate of %dHz.\n"
  35                        "Using rate of %dHz instead.\n",
  36                        timer, rate,
  37                        (V850E_TIMER_D_BASE_FREQ >> divlog2) >> 16);
  38
  39        /* Do the actual hardware timer initialization:  */
  40
  41        /* Enable timer.  */
  42        V850E_TIMER_D_TMCD(timer) = V850E_TIMER_D_TMCD_CAE;
  43        /* Set clock divider.  */
  44        V850E_TIMER_D_TMCD(timer)
  45                = V850E_TIMER_D_TMCD_CAE
  46                | V850E_TIMER_D_TMCD_CS(divlog2);
  47        /* Set timer compare register.  */
  48        V850E_TIMER_D_CMD(timer) = count;
  49        /* Start counting.  */
  50        V850E_TIMER_D_TMCD(timer)
  51                = V850E_TIMER_D_TMCD_CAE
  52                | V850E_TIMER_D_TMCD_CS(divlog2)
  53                | V850E_TIMER_D_TMCD_CE;
  54}
  55