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           /* nothing to do for mydev, this is where resources that
  43              need to be allocated/initialised before open is called
  44              can be set up */
  45 }
  46
  47 /*
  48  * Handle an open request on the device.
  49  */
  50 int
  51 mydevopen(dev_t device, int flags, int fmt, struct lwp *process)
  52 {
  53         return 0; /* this always succeeds */
  54 }
  55
  56 /*
  57  * Handle the close request for the device.
  58  */
  59 int
  60 mydevclose(dev_t device, int flags, int fmt, struct lwp *process)
  61 {
  62         return 0; /* again this always succeeds */
  63 }
  64
  65 /*
  66  * Handle the ioctl for the device
  67  */
  68 int
  69 mydevioctl(dev_t device, u_long command, caddr_t data, int flags,
  70               struct lwp *process)
  71 {
  72         int error;
  73         struct mydev_params *params = (struct mydev_params *)data;
  74
  75         error = 0;
  76         switch (command) {
  77                 case MYDEVTEST:
  78                         printf("Got number of %d and string of %s\n",
  79                                params->number, params->string);
  80                         break;
  81
  82                 default:
  83                         error = ENODEV;
  84         }
  85
  86         return (error);
  87 }