drivers/char/resetswitch.c

   1 /***************************************************************************/
   2
   3 /*
   4  *      linux/drivers/char/resetswitch.c
   5  *
   6  *      Basic driver to support the NETtel software reset button.
   7  *
   8  *      Copyright (C) 1999-2002, Greg Ungerer (gerg@snapgear.com)
   9  */
  10
  11 /***************************************************************************/
  12
  13 #include <linux/config.h>
  14 #include <linux/module.h>
  15 #include <linux/kernel.h>
  16 #include <linux/sched.h>
  17 #include <linux/param.h>
  18 #include <linux/init.h>
  19 #include <asm/irq.h>
  20 #include <asm/traps.h>
  21 #include <asm/machdep.h>
  22 #include <asm/coldfire.h>
  23 #include <asm/mcftimer.h>
  24 #include <asm/mcfsim.h>
  25 #include <asm/delay.h>
  26
  27 /***************************************************************************/
  28 #ifdef CONFIG_M5272
  29 /***************************************************************************/
  30
  31 /*
  32  *      Off-course the 5272 would have to deal with setting up and
  33  *      acknowledging interrupts differently to all other ColdFIre's!
  34  */
  35 #define SWITCH_IRQ      65
  36
  37 static void __inline__ mcf_enablevector(int vecnr)
  38 {
  39         volatile unsigned long  *icrp;
  40         icrp = (volatile unsigned long *) (MCF_MBAR + MCFSIM_ICR1);
  41         *icrp = (*icrp & 0x07777777) | 0xf0000000;
  42 }
  43
  44 static void __inline__ mcf_disablevector(void)
  45 {
  46         volatile unsigned long  *icrp;
  47         icrp = (volatile unsigned long *) (MCF_MBAR + MCFSIM_ICR1);
  48         *icrp = (*icrp & 0x07777777) | 0x80000000;
  49 }
  50
  51 static void __inline__ mcf_ackvector(void)
  52 {
  53         volatile unsigned long  *icrp;
  54         icrp = (volatile unsigned long *) (MCF_MBAR + MCFSIM_ICR1);
  55         *icrp = (*icrp & 0x07777777) | 0xf0000000;
  56 }
  57
  58 static __inline__ int mcf_isvector(void)
  59 {
  60         return((*((volatile unsigned long *) (MCF_MBAR + MCFSIM_ISR)) & 0x80000000) == 0);
  61 }
  62
  63 /***************************************************************************/
  64 #else
  65 /***************************************************************************/
  66
  67 /*
  68  *      Common vector setup for 5206e, 5307 and 5407.
  69  */
  70 #define SWITCH_IRQ      31
  71
  72 static void __inline__ mcf_enablevector(int vecnr)
  73 {
  74 }
  75
  76 static void __inline__ mcf_disablevec(void)
  77 {
  78         mcf_setimr(mcf_getimr() | MCFSIM_IMR_EINT7);
  79 }
  80
  81 static void __inline__ mcf_ackvector(void)
  82 {
  83         mcf_setimr(mcf_getimr() & ~MCFSIM_IMR_EINT7);
  84 }
  85
  86 static __inline__ int mcf_isvector(void)
  87 {
  88         return(mcf_getipr() & MCFSIM_IMR_EINT7);
  89 }
  90
  91 /***************************************************************************/
  92 #endif /* !CONFIG_M5272 */
  93 /***************************************************************************/
  94
  95 void resetswitch_button(int irq, void *dev_id, struct pt_regs *regs)
  96 {
  97         extern void     flash_eraseconfig(void);
  98         static int      inbutton = 0;
  99
 100         /*
 101          *      IRQ7 is not maskable by the CPU core. It is possible
 102          *      that switch bounce mey get us back here before we have
 103          *      really serviced the interrupt.
 104          */
 105         if (inbutton)
 106                 return;
 107         inbutton = 1;
 108
 109         /* Disable interrupt at SIM - best we can do... */
 110 #if 0
 111         mcf_disablevec();
 112 #endif
 113
 114         /* Try and de-bounce the switch a little... */
 115         udelay(10000);
 116
 117 #ifdef CONFIG_BLK_DEV_BLKMEM
 118         flash_eraseconfig();
 119 #endif
 120
 121         /* Don't leave here 'till button is no longer pushed! */
 122         for (;;) {
 123                 if (mcf_isvector() != 0)
 124                         break;
 125         }
 126
 127         HARD_RESET_NOW();
 128         /* Should never get here... */
 129
 130         inbutton = 0;
 131
 132         mcf_ackvector();
 133 }
 134
 135 /***************************************************************************/
 136
 137 int resetswitch_init(void)
 138 {
 139         mcf_enablevector(SWITCH_IRQ);
 140         mcf_autovector(SWITCH_IRQ);
 141         request_irq(SWITCH_IRQ, resetswitch_button,
 142                 (SA_INTERRUPT | IRQ_FLG_FAST), "Reset Button", NULL);
 143         return(0);
 144 }
 145
 146 module_init(resetswitch_init);
 147
 148 /***************************************************************************/