arch/sh/boards/renesas/r7780rp/led.c

   1 /*
   2  * Copyright (C) Atom Create Engineering Co., Ltd.
   3  *
   4  * May be copied or modified under the terms of GNU General Public
   5  * License.  See linux/COPYING for more information.
   6  *
   7  * This file contains Renesas Solutions HIGHLANDER R7780RP-1 specific LED code.
   8  */
   9 #include <linux/sched.h>
  10 #include <asm/io.h>
  11 #include <asm/r7780rp/r7780rp.h>
  12
  13 /* Cycle the LED's in the clasic Knightriger/Sun pattern */
  14 void heartbeat_r7780rp(void)
  15 {
  16         static unsigned int cnt = 0, period = 0;
  17         volatile unsigned short *p = (volatile unsigned short *)PA_OBLED;
  18         static unsigned bit = 0, up = 1;
  19         unsigned bit_pos[] = {2, 1, 0, 3, 6, 5, 4, 7};
  20
  21         cnt += 1;
  22         if (cnt < period)
  23                 return;
  24
  25         cnt = 0;
  26
  27         /* Go through the points (roughly!):
  28          * f(0)=10, f(1)=16, f(2)=20, f(5)=35, f(int)->110
  29          */
  30         period = 110 - ((300 << FSHIFT)/((avenrun[0]/5) + (3<<FSHIFT)));
  31
  32         *p = 1 << bit_pos[bit];
  33         if (up)
  34                 if (bit == 7) {
  35                         bit--;
  36                         up = 0;
  37                 } else
  38                         bit++;
  39         else if (bit == 0)
  40                 up = 1;
  41         else
  42                 bit--;
  43 }