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#include <errno.h>
#include "bits.h"
#include "displayid.h"
#include "displayid2.h"
/**
* The size of the mandatory fields in a DisplayID v2 section.
*/
#define DISPLAYID2_MIN_SIZE 5
/**
* The maximum size of a DisplayID v2 section.
*/
#define DISPLAYID2_MAX_SIZE 256
static bool
validate_checksum(const uint8_t *data, size_t size)
{
uint8_t sum = 0;
size_t i;
for (i = 0; i < size; i++) {
sum += data[i];
}
return sum == 0;
}
bool
_di_displayid2_parse(struct di_displayid2 *displayid2, const uint8_t *data,
size_t size, struct di_logger *logger)
{
size_t section_size;
int version;
uint8_t product_primary_use_case;
if (size < DISPLAYID2_MIN_SIZE) {
errno = EINVAL;
return false;
}
displayid2->logger = logger;
version = _di_displayid_parse_version(data, size);
displayid2->revision = get_bit_range(data[0x00], 3, 0);
if (version != 2) {
errno = ENOTSUP;
return false;
}
section_size = (size_t) data[0x01] + DISPLAYID2_MIN_SIZE;
if (section_size > DISPLAYID2_MAX_SIZE || section_size > size) {
errno = EINVAL;
return false;
}
if (!validate_checksum(data, section_size)) {
errno = EINVAL;
return false;
}
product_primary_use_case = data[0x02];
switch (product_primary_use_case) {
case DI_DISPLAYID2_PRODUCT_PRIMARY_USE_CASE_EXTENSION:
case DI_DISPLAYID2_PRODUCT_PRIMARY_USE_CASE_TEST:
case DI_DISPLAYID2_PRODUCT_PRIMARY_USE_CASE_GENERIC:
case DI_DISPLAYID2_PRODUCT_PRIMARY_USE_CASE_TV:
case DI_DISPLAYID2_PRODUCT_PRIMARY_USE_CASE_DESKTOP_PRODUCTIVITY:
case DI_DISPLAYID2_PRODUCT_PRIMARY_USE_CASE_DESKTOP_GAMING:
case DI_DISPLAYID2_PRODUCT_PRIMARY_USE_CASE_PRESENTATION:
case DI_DISPLAYID2_PRODUCT_PRIMARY_USE_CASE_HMD_VR:
case DI_DISPLAYID2_PRODUCT_PRIMARY_USE_CASE_HMD_AR:
displayid2->product_primary_use_case = product_primary_use_case;
break;
default:
errno = EINVAL;
return false;
}
displayid2->logger = NULL;
return true;
}
int
di_displayid2_get_revision(const struct di_displayid2 *displayid2)
{
return displayid2->revision;
}
enum di_displayid2_product_primary_use_case
di_displayid2_get_product_primary_use_case(const struct di_displayid2 *displayid2)
{
return displayid2->product_primary_use_case;
}
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