drivers/devfreq/devfreq.c

31 #include "governor.h"
253  * find_devfreq_governor() - find devfreq governor from name
254  * @name:	name of the governor
257  * governor's pointer. devfreq_list_lock should be held by the caller.
279  * try_then_request_governor() - Try to find the governor and request the
281  * @name:	name of the governor
284  * if is not found. This can happen when both drivers (the governor driver
287  * governor's pointer or an error pointer.
291 	struct devfreq_governor *governor;
301 	governor = find_devfreq_governor(name);
302 	if (IS_ERR(governor)) {
315 		governor = find_devfreq_governor(name);
318 	return governor;
395  *		is only used for devfreq device using passive governor.
408 	if (!devfreq->governor)
412 	err = devfreq->governor->get_target_freq(devfreq, &freq);
479  * called by devfreq governor in response to the DEVFREQ_GOV_START event
484 	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
517  * to be called from governor in response to DEVFREQ_GOV_STOP
522 	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
542  * to be called from governor in response to DEVFREQ_GOV_SUSPEND
561 	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
573  * to be called from governor in response to DEVFREQ_GOV_RESUME
582 	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
612  * to be called from governor in response to DEVFREQ_GOV_UPDATE_INTERVAL event.
622 	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
798  * @data:	devfreq driver pass to governors, governor should not change it.
806 	struct devfreq_governor *governor;
942 	governor = try_then_request_governor(governor_name);
943 	if (IS_ERR(governor)) {
944 		dev_err(dev, "%s: Unable to find governor for the device\n",
946 		err = PTR_ERR(governor);
950 	devfreq->governor = governor;
951 	err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START,
955 			"%s: Unable to start governor for the device\n",
959 	create_sysfs_files(devfreq, devfreq->governor);
998 	if (devfreq->governor) {
999 		devfreq->governor->event_handler(devfreq,
1001 		remove_sysfs_files(devfreq, devfreq->governor);
1030  * @data:	 devfreq driver pass to governors, governor should not change it.
1162 	if (devfreq->governor) {
1163 		ret = devfreq->governor->event_handler(devfreq,
1207 	if (devfreq->governor) {
1208 		ret = devfreq->governor->event_handler(devfreq,
1263  * devfreq_add_governor() - Add devfreq governor
1264  * @governor:	the devfreq governor to be added
1266 int devfreq_add_governor(struct devfreq_governor *governor)
1272 	if (!governor) {
1278 	g = find_devfreq_governor(governor->name);
1280 		pr_err("%s: governor %s already registered\n", __func__,
1286 	list_add(&governor->node, &devfreq_governor_list);
1292 		if (!strncmp(devfreq->governor->name, governor->name,
1295 			if (devfreq->governor) {
1298 					 __func__, devfreq->governor->name);
1299 				ret = devfreq->governor->event_handler(devfreq,
1305 						 devfreq->governor->name, ret);
1309 			devfreq->governor = governor;
1310 			ret = devfreq->governor->event_handler(devfreq,
1314 					 __func__, devfreq->governor->name,
1327 static void devm_devfreq_remove_governor(void *governor)
1329 	WARN_ON(devfreq_remove_governor(governor));
1333  * devm_devfreq_add_governor() - Add devfreq governor
1334  * @dev:	device which adds devfreq governor
1335  * @governor:	the devfreq governor to be added
1340 			      struct devfreq_governor *governor)
1344 	err = devfreq_add_governor(governor);
1349 					governor);
1355  * @governor:	the devfreq governor to be removed
1357 int devfreq_remove_governor(struct devfreq_governor *governor)
1363 	if (!governor) {
1369 	g = find_devfreq_governor(governor->name);
1371 		pr_err("%s: governor %s not registered\n", __func__,
1372 		       governor->name);
1380 		if (!devfreq->governor)
1383 		if (!strncmp(devfreq->governor->name, governor->name,
1385 			ret = devfreq->governor->event_handler(devfreq,
1389 					 __func__, devfreq->governor->name,
1392 			devfreq->governor = NULL;
1396 	list_del(&governor->node);
1417 	if (!df->governor)
1420 	return sprintf(buf, "%s\n", df->governor->name);
1429 	const struct devfreq_governor *governor, *prev_governor;
1431 	if (!df->governor)
1439 	governor = try_then_request_governor(str_governor);
1440 	if (IS_ERR(governor)) {
1441 		ret = PTR_ERR(governor);
1444 	if (df->governor == governor) {
1447 	} else if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)
1448 		|| IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) {
1454 	 * Stop the current governor and remove the specific sysfs files
1455 	 * which depend on current governor.
1457 	ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1460 			 __func__, df->governor->name, ret);
1463 	remove_sysfs_files(df, df->governor);
1466 	 * Start the new governor and create the specific sysfs files
1467 	 * which depend on the new governor.
1469 	prev_governor = df->governor;
1470 	df->governor = governor;
1471 	ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1474 			 __func__, df->governor->name, ret);
1476 		/* Restore previous governor */
1477 		df->governor = prev_governor;
1478 		ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1483 			df->governor = NULL;
1489 	 * Create the sysfs files for the new governor. But if failed to start
1490 	 * the new governor, restore the sysfs files of previous governor.
1492 	create_sysfs_files(df, df->governor);
1501 static DEVICE_ATTR_RW(governor);
1510 	if (!df->governor)
1516 	 * The devfreq with immutable governor (e.g., passive) shows
1517 	 * only own governor.
1519 	if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)) {
1521 				  "%s ", df->governor->name);
1523 	 * The devfreq device shows the registered governor except for
1524 	 * immutable governors such as passive governor .
1527 		struct devfreq_governor *governor;
1529 		list_for_each_entry(governor, &devfreq_governor_list, node) {
1530 			if (IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE))
1533 					   "%s ", governor->name);
1831 	if (!df->governor)
1838 	df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value);
1864 	if (!df->governor || !df->profile)
1892 	ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1895 			 __func__, df->governor->name, ret);
1899 	ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1902 			 __func__, df->governor->name, ret);
1918 /* Create the specific sysfs files which depend on each governor. */
1928 /* Remove the specific sysfs files which depend on each governor. */
1960 			"governor",
1980 		if (!strncmp(devfreq->governor->name, DEVFREQ_GOV_PASSIVE,
1996 		if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, POLLING_INTERVAL))
2006 			devfreq->governor->name,