arch/v850/kernel/v850e_timer_d.c

   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.  */
  23 void 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 }