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| Kernel Functions for Drivers | ddi_peek(9F) |
| | 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
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#include <sys/ddi.h>
#include <sys/sunddi.h>
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); |
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Solaris DDI specific (Solaris DDI).
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-
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.
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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 process where necessary.
If the address is not valid, or the value cannot be read without an
error occurring, an error code is returned.
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.
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-
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.
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These functions can be called from user or interrupt context.
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| | Example 1. Checking to see that the status register
of a device is mapped into the kernel address space:
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if (ddi_peek8(dip, csr, (int8_t *)0) != DDI_SUCCESS) {
cmn_err(CE_WARN, "Status register not mapped");
return (DDI_FAILURE);
}
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Example 2. Reading and logging the device type of a
particular device:
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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:
/* free any resources allocated */
...
return (DDI_FAILURE);
}
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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 |
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