arch/sh/boards/se/770x/led.c

   1 /*
   2  * linux/arch/sh/kernel/led_se.c
   3  *
   4  * Copyright (C) 2000 Stuart Menefy <stuart.menefy@st.com>
   5  *
   6  * May be copied or modified under the terms of the GNU General Public
   7  * License.  See linux/COPYING for more information.
   8  *
   9  * This file contains Solution Engine specific LED code.
  10  */
  11
  12 #include <linux/config.h>
  13 #include <asm/se/se.h>
  14
  15 static void mach_led(int position, int value)
  16 {
  17         volatile unsigned short* p = (volatile unsigned short*)PA_LED;
  18
  19         if (value) {
  20                 *p |= (1<<8);
  21         } else {
  22                 *p &= ~(1<<8);
  23         }
  24 }
  25
  26 #ifdef CONFIG_HEARTBEAT
  27
  28 #include <linux/sched.h>
  29
  30 /* Cycle the LED's in the clasic Knightrider/Sun pattern */
  31 void heartbeat_se(void)
  32 {
  33         static unsigned int cnt = 0, period = 0;
  34         volatile unsigned short* p = (volatile unsigned short*)PA_LED;
  35         static unsigned bit = 0, up = 1;
  36
  37         cnt += 1;
  38         if (cnt < period) {
  39                 return;
  40         }
  41
  42         cnt = 0;
  43
  44         /* Go through the points (roughly!):
  45          * f(0)=10, f(1)=16, f(2)=20, f(5)=35,f(inf)->110
  46          */
  47         period = 110 - ( (300<<FSHIFT)/
  48                          ((avenrun[0]/5) + (3<<FSHIFT)) );
  49
  50         if (up) {
  51                 if (bit == 7) {
  52                         bit--;
  53                         up=0;
  54                 } else {
  55                         bit ++;
  56                 }
  57         } else {
  58                 if (bit == 0) {
  59                         bit++;
  60                         up=1;
  61                 } else {
  62                         bit--;
  63                 }
  64         }
  65         *p = 1<<(bit+8);
  66
  67 }
  68 #endif /* CONFIG_HEARTBEAT */