/**
@param method The full name of ACPI method to call
@param argc The number of parameters
@param argv A pre-allocated array of arguments of type acpi_object
*/
static void do_acpi_call(const char * method, int argc, union acpi_object *argv)
{
acpi_status status;
acpi_handle handle;
struct acpi_object_list arg;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
// argv can be NULL if 'fn' instead of 'fn ' or 'fn arg' is called
if (argv) {
*result_buffer = '\0';
acpi_result_to_string(argv);
pr_debug("Calling %s %s\n", method, result_buffer);
} else {
pr_debug("Calling %s\n", method);
}
// get the handle of the method, must be a fully qualified path
status = acpi_get_handle(NULL, (acpi_string) method, &handle);
if (ACPI_FAILURE(status))
{
snprintf(result_buffer, BUFFER_SIZE, "Error: %s", acpi_format_exception(status));
pr_debug("Cannot get handle: %s\n", result_buffer);
return;
}
// prepare parameters
arg.count = argc;
arg.pointer = argv;
// call the method
status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
if (ACPI_FAILURE(status))
{
snprintf(result_buffer, BUFFER_SIZE, "Error: %s", acpi_format_exception(status));
pr_debug("Method call failed: %s\n", result_buffer);
return;
}
// reset the result buffer
*result_buffer = '\0';
acpi_result_to_string(buffer.pointer);
kfree(buffer.pointer);
pr_debug("Call successful: %s\n", result_buffer);
}
/** Appends the contents of an acpi_object to the result buffer
@param result An acpi object holding result data
@returns 0 if the result could fully be saved, a higher value otherwise
*/
static int acpi_result_to_string(union acpi_object *result) {
if (result->type == ACPI_TYPE_INTEGER) {
snprintf(get_buffer_end(), get_avail_bytes(),
"0x%x", (int)result->integer.value);
} else if (result->type == ACPI_TYPE_STRING) {
snprintf(get_buffer_end(), get_avail_bytes(),
"\"%*s\"", result->string.length, result->string.pointer);
} else if (result->type == ACPI_TYPE_BUFFER) {
int i;
// do not store more than data if it does not fit. The first element is
// just 4 chars, but there is also two bytes from the curly brackets
int show_values = min((size_t)result->buffer.length, get_avail_bytes() / 6);
snprintf(get_buffer_end(), get_avail_bytes(), "{");
for (i = 0; i < show_values; i++)
sprintf(get_buffer_end(),
i == 0 ? "0x%02x" : ", 0x%02x", result->buffer.pointer[i]);
if (result->buffer.length > show_values) {
// if data was truncated, show a trailing comma if there is space
snprintf(get_buffer_end(), get_avail_bytes(), ",");
return 1;
} else {
// in case show_values == 0, but the buffer is too small to hold
// more values (i.e. the buffer cannot have anything more than "{")
snprintf(get_buffer_end(), get_avail_bytes(), "}");
}
} else if (result->type == ACPI_TYPE_PACKAGE) {
int i;
snprintf(get_buffer_end(), get_avail_bytes(), "[");
for (i=0; i<result->package.count; i++) {
if (i > 0)
snprintf(get_buffer_end(), get_avail_bytes(), ", ");
// abort if there is no more space available
if (!get_avail_bytes() || acpi_result_to_string(&result->package.elements[i]))
return 1;
}
snprintf(get_buffer_end(), get_avail_bytes(), "]");
} else {
snprintf(get_buffer_end(), get_avail_bytes(),
"Object type 0x%x\n", result->type);
}
// return 0 if there are still bytes available, 1 otherwise
return !get_avail_bytes();
}
/**
@param method The full name of ACPI method to call
@param argc The number of parameters
@param argv A pre-allocated array of arguments of type acpi_object
*/
static void do_acpi_call(const char * method, int argc, union acpi_object *argv)
{
acpi_status status;
acpi_handle handle;
struct acpi_object_list arg;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
#ifdef DEBUG
printk(KERN_INFO "acpi_call: Calling %s\n", method);
#endif
// get the handle of the method, must be a fully qualified path
status = acpi_get_handle(NULL, (acpi_string) method, &handle);
if (ACPI_FAILURE(status))
{
snprintf(result_buffer, BUFFER_SIZE, "Error: %s", acpi_format_exception(status));
printk(KERN_ERR "acpi_call: Cannot get handle: %s\n", result_buffer);
return;
}
// prepare parameters
arg.count = argc;
arg.pointer = argv;
// call the method
status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
if (ACPI_FAILURE(status))
{
snprintf(result_buffer, BUFFER_SIZE, "Error: %s", acpi_format_exception(status));
printk(KERN_ERR "acpi_call: Method call failed: %s\n", result_buffer);
return;
}
// reset the result buffer
*result_buffer = '\0';
acpi_result_to_string(buffer.pointer);
kfree(buffer.pointer);
#ifdef DEBUG
printk(KERN_INFO "acpi_call: Call successful: %s\n", result_buffer);
#endif
}
