hardware: add ro.hardware.<class> to HAL loading properites list

Try to load a HAL determined by ro.hardware.<class> first before
falling back to hardware, board, platform, arch, and default.
This is intended to be used to support multiple hardware variants
from the same source.  For example, a single build that supports
two gps chips, gps001 and gpsb, could use /factory/factory.prop
to set ro.hardware.gps=gps001 or ro.hardware.gps=gpsb, which would
load gps.gps001.so or gps.gpsb.so.  Two separate builds from the
same source could use PRODUCT_PROPERTY_OVERRIDES to set the
properties.

Change-Id: I1ac46c21ceb27ceb5165e8c44e9373e9c5d4e34e
This commit is contained in:
Colin Cross 2013-12-26 13:47:56 -08:00
parent 20ebefd966
commit 85ab5d1f91

View file

@ -117,15 +117,34 @@ static int load(const char *id,
return status;
}
/*
* Check if a HAL with given name and subname exists, if so return 0, otherwise
* otherwise return negative. On success path will contain the path to the HAL.
*/
static int hw_module_exists(char *path, size_t path_len, const char *name,
const char *subname)
{
snprintf(path, path_len, "%s/%s.%s.so",
HAL_LIBRARY_PATH2, name, subname);
if (access(path, R_OK) == 0)
return 0;
snprintf(path, path_len, "%s/%s.%s.so",
HAL_LIBRARY_PATH1, name, subname);
if (access(path, R_OK) == 0)
return 0;
return -ENOENT;
}
int hw_get_module_by_class(const char *class_id, const char *inst,
const struct hw_module_t **module)
{
int status;
int i;
const struct hw_module_t *hmi = NULL;
char prop[PATH_MAX];
char path[PATH_MAX];
char name[PATH_MAX];
char prop_name[PATH_MAX];
if (inst)
snprintf(name, PATH_MAX, "%s.%s", class_id, inst);
@ -139,38 +158,35 @@ int hw_get_module_by_class(const char *class_id, const char *inst,
* We also assume that dlopen() is thread-safe.
*/
/* First try a property specific to the class and possibly instance */
snprintf(prop_name, sizeof(prop_name), "ro.hardware.%s", name);
if (property_get(prop_name, prop, NULL) == 0) {
if (hw_module_exists(path, sizeof(path), name, prop) == 0) {
goto found;
}
}
/* Loop through the configuration variants looking for a module */
for (i=0 ; i<HAL_VARIANT_KEYS_COUNT+1 ; i++) {
if (i < HAL_VARIANT_KEYS_COUNT) {
for (i=0 ; i<HAL_VARIANT_KEYS_COUNT; i++) {
if (property_get(variant_keys[i], prop, NULL) == 0) {
continue;
}
snprintf(path, sizeof(path), "%s/%s.%s.so",
HAL_LIBRARY_PATH2, name, prop);
if (access(path, R_OK) == 0) break;
snprintf(path, sizeof(path), "%s/%s.%s.so",
HAL_LIBRARY_PATH1, name, prop);
if (access(path, R_OK) == 0) break;
} else {
snprintf(path, sizeof(path), "%s/%s.default.so",
HAL_LIBRARY_PATH2, name);
if (access(path, R_OK) == 0) break;
snprintf(path, sizeof(path), "%s/%s.default.so",
HAL_LIBRARY_PATH1, name);
if (access(path, R_OK) == 0) break;
if (hw_module_exists(path, sizeof(path), name, prop) == 0) {
goto found;
}
}
status = -ENOENT;
if (i < HAL_VARIANT_KEYS_COUNT+1) {
/* Nothing found, try the default */
if (hw_module_exists(path, sizeof(path), name, "default") == 0) {
goto found;
}
return -ENOENT;
found:
/* load the module, if this fails, we're doomed, and we should not try
* to load a different variant. */
status = load(class_id, path, module);
}
return status;
return load(class_id, path, module);
}
int hw_get_module(const char *id, const struct hw_module_t **module)