arch/sh/boards/se/7751/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 <asm/se7751/se7751.h>
  13
  14 static void mach_led(int position, int value)
  15 {
  16         volatile unsigned short* p = (volatile unsigned short*)PA_LED;
  17
  18         if (value) {
  19                 *p |= (1<<8);
  20         } else {
  21                 *p &= ~(1<<8);
  22         }
  23 }
  24
  25 #ifdef CONFIG_HEARTBEAT
  26
  27 #include <linux/sched.h>
  28
  29 /* Cycle the LED's in the clasic Knightrider/Sun pattern */
  30 void heartbeat_7751se(void)
  31 {
  32         static unsigned int cnt = 0, period = 0;
  33         volatile unsigned short* p = (volatile unsigned short*)PA_LED;
  34         static unsigned bit = 0, up = 1;
  35
  36         cnt += 1;
  37         if (cnt < period) {
  38                 return;
  39         }
  40
  41         cnt = 0;
  42
  43         /* Go through the points (roughly!):
  44          * f(0)=10, f(1)=16, f(2)=20, f(5)=35,f(inf)->110
  45          */
  46         period = 110 - ( (300<<FSHIFT)/
  47                          ((avenrun[0]/5) + (3<<FSHIFT)) );
  48
  49         if (up) {
  50                 if (bit == 7) {
  51                         bit--;
  52                         up=0;
  53                 } else {
  54                         bit ++;
  55                 }
  56         } else {
  57                 if (bit == 0) {
  58                         bit++;
  59                         up=1;
  60                 } else {
  61                         bit--;
  62                 }
  63         }
  64         *p = 1<<(bit+8);
  65
  66 }
  67 #endif /* CONFIG_HEARTBEAT */