DDI_PEEK(9F) | Kernel Functions for Drivers | DDI_PEEK(9F) |
#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);
addr
valuep
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.
DDI_FAILURE
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 particular 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: /* free any resources allocated */ ... return (DDI_FAILURE); }
Writing Device Drivers
January 16, 2006 | OmniOS |