ddi_peek16(9f)

1ddi_peek(9F)             Kernel Functions for Drivers             ddi_peek(9F)
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NAME

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

10       #include <sys/ddi.h>
11       #include <sys/sunddi.h>
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15       int ddi_peek8(dev_info_t *dip, int8_t *addr, int8_t *valuep);
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18       int ddi_peek16(dev_info_t *dip, int16_t *addr, int16_t *valuep);
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21       int ddi_peek32(dev_info_t *dip, int32_t *addr, int32_t *valuep);
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24       int ddi_peek64(dev_info_t *dip, int64_t *addr, int64_t *valuep);
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INTERFACE LEVEL

28       Solaris DDI  specific  (Solaris  DDI).  The  ddi_peekc(),  ddi_peeks(),
29       ddi_peekl(), and ddi_peekd() functions are obsolete. Use, respectively,
30       ddi_peek8(), ddi_peek16(), ddi_peek32(), and ddi_peek64(), instead.
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PARAMETERS

33       dip       A pointer to the device's dev_info structure.
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36       addr      Virtual address of the location to be examined.
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39       valuep    Pointer to a location to hold the result. If a  null  pointer
40                 is specified, then the value read from the location will sim‐
41                 ply be discarded.
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DESCRIPTION

45       These routines cautiously attempt to read a value from a specified vir‐
46       tual  address,  and  return  the  value to the caller, using the parent
47       nexus driver to assist in the process where necessary.
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50       If the address is not valid, or the value cannot  be  read  without  an
51       error occurring, an error code is returned.
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54       The  routines  are most useful when first trying to establish the pres‐
55       ence of a device on the system in a driver's  probe(9E)  or  attach(9E)
56       routines.
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RETURN VALUES

59       DDI_SUCCESS    The  value at the given virtual address was successfully
60                      read, and if valuep is non-null, *valuep will have  been
61                      updated.
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64       DDI_FAILURE    An  error  occurred  while  trying to read the location.
65                      *valuep is unchanged.
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CONTEXT

69       These functions can be called from user, interrupt, or kernel context.
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EXAMPLES

72       Example 1 Checking to see that the  status  register  of  a  device  is
73       mapped into the kernel address space:
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75         if (ddi_peek8(dip, csr, (int8_t *)0) != DDI_SUCCESS) {
76                 cmn_err(CE_WARN, "Status register not mapped");
77                 return (DDI_FAILURE);
78         }
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81       Example 2 Reading and logging the device type of a particular device:
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83         int
84         xx_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
85         {
86                ...
87               /* map device registers */
88                ...
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90               if (ddi_peek32(dip, id_addr, &id_value) != DDI_SUCCESS) {
91                       cmn_err(CE_WARN, "%s%d: cannot read device identifier",
92                         ddi_get_name(dip), ddi_get_instance(dip));
93                       goto failure;
94               } else
95                       cmn_err(CE_CONT, "!%s%d: device type 0x%x\n",
96                         ddi_get_name(dip), ddi_get_instance(dip), id_value);
97                    ...
98                    ...
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100               ddi_report_dev(dip);
101               return (DDI_SUCCESS);
102
103         failure:
104               /* free any resources allocated */
105               ...
106               return (DDI_FAILURE);
107         }
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NOTES

117       The  functions  described  in this manual page previously used symbolic
118       names which specified their data access size; the function  names  have
119       been  changed so they now specify a fixed-width data size. See the fol‐
120       lowing table for the new name equivalents:
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125       ┌───────────────────────────────────────────────────────────┐
126       │Previous Name                 New Name                     │
127       │ddi_peekc                     ddi_peek8                    │
128       │ddi_peeks                     ddi_peek16                   │
129       │ddi_peekl                     ddi_peek32                   │
130       │ddi_peekd                     ddi_peek64                   │
131       └───────────────────────────────────────────────────────────┘
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135SunOS 5.11                        16 Jan 2006                     ddi_peek(9F)