arch/sh/boards/mpc1211/led.c

   1 /*
   2  * linux/arch/sh/boards/mpc1211/led.c
   3  *
   4  * Copyright (C) 2001  Saito.K & Jeanne
   5  *
   6  * This file contains Interface MPC-1211 specific LED code.
   7  */
   8
   9
  10 static void mach_led(int position, int value)
  11 {
  12         volatile unsigned char* p = (volatile unsigned char*)0xa2000000;
  13
  14         if (value) {
  15                 *p |= 1;
  16         } else {
  17                 *p &= ~1;
  18         }
  19 }
  20
  21 #ifdef CONFIG_HEARTBEAT
  22
  23 #include <linux/sched.h>
  24
  25 /* Cycle the LED's in the clasic Knightrider/Sun pattern */
  26 void heartbeat_mpc1211(void)
  27 {
  28         static unsigned int cnt = 0, period = 0;
  29         volatile unsigned char* p = (volatile unsigned char*)0xa2000000;
  30         static unsigned bit = 0, up = 1;
  31
  32         cnt += 1;
  33         if (cnt < period) {
  34                 return;
  35         }
  36
  37         cnt = 0;
  38
  39         /* Go through the points (roughly!):
  40          * f(0)=10, f(1)=16, f(2)=20, f(5)=35,f(inf)->110
  41          */
  42         period = 110 - ( (300<<FSHIFT)/
  43                          ((avenrun[0]/5) + (3<<FSHIFT)) );
  44
  45         if (up) {
  46                 if (bit == 7) {
  47                         bit--;
  48                         up=0;
  49                 } else {
  50                         bit ++;
  51                 }
  52         } else {
  53                 if (bit == 0) {
  54                         bit++;
  55                         up=1;
  56                 } else {
  57                         bit--;
  58                 }
  59         }
  60         *p = 1<<bit;
  61
  62 }
  63 #endif /* CONFIG_HEARTBEAT */