arch/sh/boards/mpc1211/led.c

   1 /*
   2  * linux/arch/sh/kernel/led_mpc1211.c
   3  *
   4  * Copyright (C) 2001  Saito.K & Jeanne
   5  *
   6  * This file contains Interface MPC-1211 specific LED code.
   7  */
   8
   9 #include <linux/config.h>
  10
  11 static void mach_led(int position, int value)
  12 {
  13         volatile unsigned char* p = (volatile unsigned char*)0xa2000000;
  14
  15         if (value) {
  16                 *p |= 1;
  17         } else {
  18                 *p &= ~1;
  19         }
  20 }
  21
  22 #ifdef CONFIG_HEARTBEAT
  23
  24 #include <linux/sched.h>
  25
  26 /* Cycle the LED's in the clasic Knightrider/Sun pattern */
  27 void heartbeat_mpc1211(void)
  28 {
  29         static unsigned int cnt = 0, period = 0;
  30         volatile unsigned char* p = (volatile unsigned char*)0xa2000000;
  31         static unsigned bit = 0, up = 1;
  32
  33         cnt += 1;
  34         if (cnt < period) {
  35                 return;
  36         }
  37
  38         cnt = 0;
  39
  40         /* Go through the points (roughly!):
  41          * f(0)=10, f(1)=16, f(2)=20, f(5)=35,f(inf)->110
  42          */
  43         period = 110 - ( (300<<FSHIFT)/
  44                          ((avenrun[0]/5) + (3<<FSHIFT)) );
  45
  46         if (up) {
  47                 if (bit == 7) {
  48                         bit--;
  49                         up=0;
  50                 } else {
  51                         bit ++;
  52                 }
  53         } else {
  54                 if (bit == 0) {
  55                         bit++;
  56                         up=1;
  57                 } else {
  58                         bit--;
  59                 }
  60         }
  61         *p = 1<<bit;
  62
  63 }
  64 #endif /* CONFIG_HEARTBEAT */