arch/sh/include/cpu-sh2/cpu/watchdog.h

   1 /*
   2  * include/asm-sh/cpu-sh2/watchdog.h
   3  *
   4  * Copyright (C) 2002, 2003 Paul Mundt
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10 #ifndef __ASM_CPU_SH2_WATCHDOG_H
  11 #define __ASM_CPU_SH2_WATCHDOG_H
  12
  13 /*
  14  * More SH-2 brilliance .. its not good enough that we can't read
  15  * and write the same sizes to WTCNT, now we have to read and write
  16  * with different sizes at different addresses for WTCNT _and_ RSTCSR.
  17  *
  18  * At least on the bright side no one has managed to screw over WTCSR
  19  * in this fashion .. yet.
  20  */
  21 /* Register definitions */
  22 #define WTCNT           0xfffffe80
  23 #define WTCSR           0xfffffe80
  24 #define RSTCSR          0xfffffe82
  25
  26 #define WTCNT_R         (WTCNT + 1)
  27 #define RSTCSR_R        (RSTCSR + 1)
  28
  29 /* Bit definitions */
  30 #define WTCSR_IOVF      0x80
  31 #define WTCSR_WT        0x40
  32 #define WTCSR_TME       0x20
  33 #define WTCSR_RSTS      0x00
  34
  35 #define RSTCSR_RSTS     0x20
  36
  37 /**
  38  *      sh_wdt_read_rstcsr - Read from Reset Control/Status Register
  39  *
  40  *      Reads back the RSTCSR value.
  41  */
  42 static inline __u8 sh_wdt_read_rstcsr(void)
  43 {
  44         /*
  45          * Same read/write brain-damage as for WTCNT here..
  46          */
  47         return __raw_readb(RSTCSR_R);
  48 }
  49
  50 /**
  51  *      sh_wdt_write_csr - Write to Reset Control/Status Register
  52  *
  53  *      @val: Value to write
  54  *
  55  *      Writes the given value @val to the lower byte of the control/status
  56  *      register. The upper byte is set manually on each write.
  57  */
  58 static inline void sh_wdt_write_rstcsr(__u8 val)
  59 {
  60         /*
  61          * Note: Due to the brain-damaged nature of this register,
  62          * we can't presently touch the WOVF bit, since the upper byte
  63          * has to be swapped for this. So just leave it alone..
  64          */
  65         __raw_writeb((WTCNT_HIGH << 8) | (__u16)val, RSTCSR);
  66 }
  67
  68 #endif /* __ASM_CPU_SH2_WATCHDOG_H */
  69