arch/sparc/prom/devops.c

   1 /*
   2  * devops.c:  Device operations using the PROM.
   3  *
   4  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   5  */
   6 #include <linux/types.h>
   7 #include <linux/kernel.h>
   8 #include <linux/sched.h>
   9
  10 #include <asm/openprom.h>
  11 #include <asm/oplib.h>
  12
  13 extern void restore_current(void);
  14
  15 /* Open the device described by the string 'dstr'.  Returns the handle
  16  * to that device used for subsequent operations on that device.
  17  * Returns -1 on failure.
  18  */
  19 int
  20 prom_devopen(char *dstr)
  21 {
  22         int handle;
  23         unsigned long flags;
  24         spin_lock_irqsave(&prom_lock, flags);
  25         switch(prom_vers) {
  26         case PROM_V0:
  27                 handle = (*(romvec->pv_v0devops.v0_devopen))(dstr);
  28                 if(handle == 0) handle = -1;
  29                 break;
  30         case PROM_V2:
  31         case PROM_V3:
  32                 handle = (*(romvec->pv_v2devops.v2_dev_open))(dstr);
  33                 break;
  34         default:
  35                 handle = -1;
  36                 break;
  37         };
  38         restore_current();
  39         spin_unlock_irqrestore(&prom_lock, flags);
  40
  41         return handle;
  42 }
  43
  44 /* Close the device described by device handle 'dhandle'. */
  45 int
  46 prom_devclose(int dhandle)
  47 {
  48         unsigned long flags;
  49         spin_lock_irqsave(&prom_lock, flags);
  50         switch(prom_vers) {
  51         case PROM_V0:
  52                 (*(romvec->pv_v0devops.v0_devclose))(dhandle);
  53                 break;
  54         case PROM_V2:
  55         case PROM_V3:
  56                 (*(romvec->pv_v2devops.v2_dev_close))(dhandle);
  57                 break;
  58         default:
  59                 break;
  60         };
  61         restore_current();
  62         spin_unlock_irqrestore(&prom_lock, flags);
  63         return 0;
  64 }
  65
  66 /* Seek to specified location described by 'seekhi' and 'seeklo'
  67  * for device 'dhandle'.
  68  */
  69 void
  70 prom_seek(int dhandle, unsigned int seekhi, unsigned int seeklo)
  71 {
  72         unsigned long flags;
  73         spin_lock_irqsave(&prom_lock, flags);
  74         switch(prom_vers) {
  75         case PROM_V0:
  76                 (*(romvec->pv_v0devops.v0_seekdev))(dhandle, seekhi, seeklo);
  77                 break;
  78         case PROM_V2:
  79         case PROM_V3:
  80                 (*(romvec->pv_v2devops.v2_dev_seek))(dhandle, seekhi, seeklo);
  81                 break;
  82         default:
  83                 break;
  84         };
  85         restore_current();
  86         spin_unlock_irqrestore(&prom_lock, flags);
  87
  88         return;
  89 }