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
  10 struct mydev_softc {
  11     struct device       mydev_dev;
  12 };
  13
  14 /* Autoconfiguration glue */
  15 void mydevattach(struct device *parent, struct device *self, void *aux);
  16 int mydevopen(dev_t device, int flags, int fmt, struct lwp *process);
  17 int mydevclose(dev_t device, int flags, int fmt, struct lwp *process);
  18 int mydevioctl(dev_t device, u_long command, caddr_t data,
  19                       int flags, struct lwp *process);
  20
  21 /* Just define the character device handlers because that is all we need */
  22 const struct cdevsw mydev_cdevsw = {
  23     mydevopen,
  24     mydevclose,
  25     noread,
  26     nowrite,
  27     mydevioctl,
  28     nostop,
  29     notty,
  30     nopoll,
  31     nommap,
  32     nokqfilter,
  33     0 /* int d_type; */
  34 };
  35
  36 /*
  37  * Attach for autoconfig to find.
  38  */
  39 void
  40 mydevattach(struct device *parent, struct device *self, void *aux)
  41 {
  42     /*
  43      * Nothing to do for mydev, this is where resources that
  44      * need to be allocated/initialised before open is called
  45      * can be set up.
  46     */
  47 }
  48
  49 /*
  50  * Handle an open request on the device.
  51  */
  52 int
  53 mydevopen(dev_t device, int flags, int fmt, struct lwp *process)
  54 {
  55         return 0; /* This always succeeds */
  56 }
  57
  58 /*
  59  * Handle the close request for the device.
  60  */
  61 int
  62 mydevclose(dev_t device, int flags, int fmt, struct lwp *process)
  63 {
  64         return 0; /* Again this always succeeds */
  65 }
  66
  67 /*
  68  * Handle the ioctl for the device.
  69  */
  70 int
  71 mydevioctl(dev_t device, u_long command, caddr_t data, int flags,
  72            struct lwp *process)
  73 {
  74     int error;
  75     struct mydev_params *params = (struct mydev_params *)data;
  76
  77     error = 0;
  78     switch (command) {
  79     case MYDEVTEST:
  80         printf("Got number of %d and string of %s\n",
  81                params->number, params->string);
  82         break;
  83
  84     default:
  85         error = ENODEV;
  86     }
  87
  88     return error;
  89 }