Manual Pages for UNIX Operating System command usage for man ddi_peek

Kernel Functions for Drivers                         ddi_peek(9F)



NAME
     ddi_peek,  ddi_peek8,  ddi_peek16,  ddi_peek32,  ddi_peek64,
     ddi_peekc,  ddi_peeks,  ddi_peekl,  ddi_peekd - read a value
     from a location

SYNOPSIS
     #include 
     #include 



     int ddi_peek8(dev_info_t *dip, int8_t *addr, int8_t *valuep);


     int ddi_peek16(dev_info_t *dip, int16_t *addr, int16_t *valuep);


     int ddi_peek32(dev_info_t *dip, int32_t *addr, int32_t *valuep);


     int ddi_peek64(dev_info_t *dip, int64_t *addr, int64_t *valuep);


INTERFACE LEVEL
     Solaris  DDI  specific  (Solaris  DDI).   The   ddi_peekc(),
     ddi_peeks(),  ddi_peekl(),  and  ddi_peekd()  functions  are
     obsolete.  Use,  respectively,  ddi_peek8(),   ddi_peek16(),
     ddi_peek32(), and ddi_peek64(), instead.

PARAMETERS
     dip       A pointer to the device's dev_info structure.


     addr      Virtual address of the location to be examined.


     valuep    Pointer to a location to hold  the  result.  If  a
               null  pointer  is  specified,  then the value read
               from the location will simply be discarded.


DESCRIPTION
     These routines cautiously attempt to read  a  value  from  a
     specified  virtual  address,  and  return  the  value to the
     caller, using the parent nexus driver to assist in the  pro-
     cess where necessary.


     If the address is not valid, or the  value  cannot  be  read
     without an error occurring, an error code is returned.





SunOS 5.11          Last change: 16 Jan 2006                    1






Kernel Functions for Drivers                         ddi_peek(9F)



     The routines are most useful when first trying to  establish
     the  presence  of  a  device  on  the  system  in a driver's
     probe(9E) or attach(9E) routines.

RETURN VALUES
     DDI_SUCCESS    The value at the given  virtual  address  was
                    successfully read, and if valuep is non-null,
                    *valuep will have been updated.


     DDI_FAILURE    An error occurred while trying  to  read  the
                    location. *valuep is unchanged.


CONTEXT
     These functions can be called from user, interrupt, or  ker-
     nel context.

EXAMPLES
     Example 1 Checking to see that the status register of a dev-
     ice is mapped into the kernel address space:

       if (ddi_peek8(dip, csr, (int8_t *)0) != DDI_SUCCESS) {
               cmn_err(CE_WARN, "Status register not mapped");
               return (DDI_FAILURE);
       }


     Example 2 Reading and logging the device type of a  particu-
     lar device:

       int
       xx_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
       {
              ...
             /* map device registers */
              ...

             if (ddi_peek32(dip, id_addr, &id_value) != DDI_SUCCESS) {
                     cmn_err(CE_WARN, "%s%d: cannot read device identifier",
                       ddi_get_name(dip), ddi_get_instance(dip));
                     goto failure;
             } else
                     cmn_err(CE_CONT, "!%s%d: device type 0x%x\n",
                       ddi_get_name(dip), ddi_get_instance(dip), id_value);
                  ...
                  ...

             ddi_report_dev(dip);
             return (DDI_SUCCESS);

       failure:



SunOS 5.11          Last change: 16 Jan 2006                    2






Kernel Functions for Drivers                         ddi_peek(9F)



             /* free any resources allocated */
             ...
             return (DDI_FAILURE);
       }


SEE ALSO
     attach(9E), probe(9E), ddi_poke(9F)


     Writing Device Drivers

NOTES
     The functions described in this manual page previously  used
     symbolic  names  which specified their data access size; the
     function names have been  changed  so  they  now  specify  a
     fixed-width  data  size. See the following table for the new
     name equivalents:



     ____________________________________________________________
    | Previous Name                 New Name                    |
    | ddi_peekc                     ddi_peek8                   |
    | ddi_peeks                     ddi_peek16                  |
    | ddi_peekl                     ddi_peek32                  |
    | ddi_peekd                     ddi_peek64                  |
    |___________________________________________________________|



























SunOS 5.11          Last change: 16 Jan 2006                    3