netbsd/cdev/mydev.c

   1 #include <sys/param.h>
   2 #include <sys/systm.h>
   3 #include <sys/proc.h>
   4 #include <sys/errno.h>
   5 #include <sys/ioctl.h>
   6 #include <sys/device.h>
   7 #include <sys/conf.h>
   8 #include <sys/mydev.h>
   9 #include <prop/proplib.h>
  10
  11 struct mydev_softc {
  12     struct device mydev_dev;
  13 };
  14
  15 /* Autoconfiguration glue */
  16 void mydevattach(struct device *parent, struct device *self, void *aux);
  17 int mydevopen(dev_t dev, int flags, int fmt, struct lwp *process);
  18 int mydevclose(dev_t dev, int flags, int fmt, struct lwp *process);
  19 int mydevioctl(dev_t dev, u_long cmd, caddr_t data,
  20                       int flags, struct lwp *process);
  21
  22 /* Just define the character dev handlers because that is all we need */
  23 const struct cdevsw mydev_cdevsw = {
  24     mydevopen,
  25     mydevclose,
  26     noread,
  27     nowrite,
  28     mydevioctl,
  29     nostop,
  30     notty,
  31     nopoll,
  32     nommap,
  33     nokqfilter,
  34     0    /* int d_type; */
  35 };
  36
  37 /*
  38  * Attach for autoconfig to find.
  39  */
  40 void
  41 mydevattach(struct device *parent, struct device *self, void *aux)
  42 {
  43     /*
  44      * Nothing to do for mydev.
  45      * This is where resources that need to be allocated/initialised
  46      * before open is called can be set up.
  47     */
  48 }
  49
  50 /*
  51  * Handle an open request on the dev.
  52  */
  53 int
  54 mydevopen(dev_t dev, int flags, int fmt, struct lwp *process)
  55 {
  56     return 0;    /* This always succeeds */
  57 }
  58
  59 /*
  60  * Handle the close request for the dev.
  61  */
  62 int
  63 mydevclose(dev_t dev, int flags, int fmt, struct lwp *process)
  64 {
  65     return 0;    /* Again this always succeeds */
  66 }
  67
  68 /*
  69  * Handle the ioctl for the dev.
  70  */
  71 int
  72 mydevioctl(dev_t dev, u_long cmd, caddr_t data, int flags,
  73            struct lwp *process)
  74 {
  75     prop_dictionary_t dict;
  76     prop_string_t ps;
  77     struct mydev_params *params;
  78     const struct plistref *pref;
  79     int error;
  80     char *val;
  81
  82     error = 0;
  83     switch (cmd) {
  84     case MYDEVTEST:
  85         /* Pass data from userspace to kernel in the conventional way */
  86         params = (struct mydev_params *)data;
  87         printf("Got number of %d and string of %s\n",
  88                params->number, params->string);
  89         break;
  90
  91     case MYDEVSETPROPS:
  92         /* Use proplib(3) for userspace/kernel communication */
  93         pref = (const struct plistref *)data;
  94         error = prop_dictionary_copyin_ioctl(pref, cmd, &dict);
  95         if (error)
  96             return error;
  97
  98         /* Print dict's count for debugging purposes */
  99         printf("count = %u\n", prop_dictionary_count(dict));
 100
 101         /* Retrieve object associated with "key" key */
 102         ps = prop_dictionary_get(dict, "key");
 103         if (ps == NULL) {
 104             prop_object_release(dict);
 105             printf("prop_dictionary_get()\n");
 106             return -1;
 107         }
 108
 109         /* Print data */
 110         val = prop_string_cstring(ps);
 111         prop_object_release(ps);
 112         printf("<key, val> = (%s, %s)\n", "key", val == NULL ? "null" : val);
 113
 114         /* Done */
 115         prop_object_release(dict);
 116         break;
 117
 118     default:
 119         /* Invalid operation */
 120         error = ENODEV;
 121     }
 122
 123     return error;
 124 }