1 // SPDX-License-Identifier: GPL-2.0-only
3 * Generic OPP OF helpers
5 * Copyright (C) 2009-2010 Texas Instruments Incorporated.
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/cpu.h>
14 #include <linux/errno.h>
15 #include <linux/device.h>
16 #include <linux/of_device.h>
17 #include <linux/pm_domain.h>
18 #include <linux/slab.h>
19 #include <linux/export.h>
20 #include <linux/energy_model.h>
25 * Returns opp descriptor node for a device node, caller must
28 static struct device_node *_opp_of_get_opp_desc_node(struct device_node *np,
31 /* "operating-points-v2" can be an array for power domain providers */
32 return of_parse_phandle(np, "operating-points-v2", index);
35 /* Returns opp descriptor node for a device, caller must do of_node_put() */
36 struct device_node *dev_pm_opp_of_get_opp_desc_node(struct device *dev)
38 return _opp_of_get_opp_desc_node(dev->of_node, 0);
40 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_opp_desc_node);
42 struct opp_table *_managed_opp(struct device *dev, int index)
44 struct opp_table *opp_table, *managed_table = NULL;
45 struct device_node *np;
47 np = _opp_of_get_opp_desc_node(dev->of_node, index);
51 list_for_each_entry(opp_table, &opp_tables, node) {
52 if (opp_table->np == np) {
54 * Multiple devices can point to the same OPP table and
55 * so will have same node-pointer, np.
57 * But the OPPs will be considered as shared only if the
58 * OPP table contains a "opp-shared" property.
60 if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
61 _get_opp_table_kref(opp_table);
62 managed_table = opp_table;
74 /* The caller must call dev_pm_opp_put() after the OPP is used */
75 static struct dev_pm_opp *_find_opp_of_np(struct opp_table *opp_table,
76 struct device_node *opp_np)
78 struct dev_pm_opp *opp;
80 lockdep_assert_held(&opp_table_lock);
82 mutex_lock(&opp_table->lock);
84 list_for_each_entry(opp, &opp_table->opp_list, node) {
85 if (opp->np == opp_np) {
87 mutex_unlock(&opp_table->lock);
92 mutex_unlock(&opp_table->lock);
97 static struct device_node *of_parse_required_opp(struct device_node *np,
100 struct device_node *required_np;
102 required_np = of_parse_phandle(np, "required-opps", index);
103 if (unlikely(!required_np)) {
104 pr_err("%s: Unable to parse required-opps: %pOF, index: %d\n",
105 __func__, np, index);
111 /* The caller must call dev_pm_opp_put_opp_table() after the table is used */
112 static struct opp_table *_find_table_of_opp_np(struct device_node *opp_np)
114 struct opp_table *opp_table;
115 struct device_node *opp_table_np;
117 lockdep_assert_held(&opp_table_lock);
119 opp_table_np = of_get_parent(opp_np);
123 /* It is safe to put the node now as all we need now is its address */
124 of_node_put(opp_table_np);
126 list_for_each_entry(opp_table, &opp_tables, node) {
127 if (opp_table_np == opp_table->np) {
128 _get_opp_table_kref(opp_table);
134 return ERR_PTR(-ENODEV);
137 /* Free resources previously acquired by _opp_table_alloc_required_tables() */
138 static void _opp_table_free_required_tables(struct opp_table *opp_table)
140 struct opp_table **required_opp_tables = opp_table->required_opp_tables;
141 struct device **genpd_virt_devs = opp_table->genpd_virt_devs;
144 if (!required_opp_tables)
147 for (i = 0; i < opp_table->required_opp_count; i++) {
148 if (IS_ERR_OR_NULL(required_opp_tables[i]))
151 dev_pm_opp_put_opp_table(required_opp_tables[i]);
154 kfree(required_opp_tables);
155 kfree(genpd_virt_devs);
157 opp_table->required_opp_count = 0;
158 opp_table->genpd_virt_devs = NULL;
159 opp_table->required_opp_tables = NULL;
163 * Populate all devices and opp tables which are part of "required-opps" list.
164 * Checking only the first OPP node should be enough.
166 static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
168 struct device_node *opp_np)
170 struct opp_table **required_opp_tables;
171 struct device **genpd_virt_devs = NULL;
172 struct device_node *required_np, *np;
173 int count, count_pd, i;
175 /* Traversing the first OPP node is all we need */
176 np = of_get_next_available_child(opp_np, NULL);
178 dev_err(dev, "Empty OPP table\n");
182 count = of_count_phandle_with_args(np, "required-opps", NULL);
187 * Check the number of power-domains to know if we need to deal
188 * with virtual devices. In some cases we have devices with multiple
189 * power domains but with only one of them being scalable, hence
190 * 'count' could be 1, but we still have to deal with multiple genpds
191 * and virtual devices.
193 count_pd = of_count_phandle_with_args(dev->of_node, "power-domains",
194 "#power-domain-cells");
199 genpd_virt_devs = kcalloc(count, sizeof(*genpd_virt_devs),
201 if (!genpd_virt_devs)
205 required_opp_tables = kcalloc(count, sizeof(*required_opp_tables),
207 if (!required_opp_tables) {
208 kfree(genpd_virt_devs);
212 opp_table->genpd_virt_devs = genpd_virt_devs;
213 opp_table->required_opp_tables = required_opp_tables;
214 opp_table->required_opp_count = count;
216 for (i = 0; i < count; i++) {
217 required_np = of_parse_required_opp(np, i);
219 goto free_required_tables;
221 required_opp_tables[i] = _find_table_of_opp_np(required_np);
222 of_node_put(required_np);
224 if (IS_ERR(required_opp_tables[i]))
225 goto free_required_tables;
228 * We only support genpd's OPPs in the "required-opps" for now,
229 * as we don't know how much about other cases. Error out if the
230 * required OPP doesn't belong to a genpd.
232 if (!required_opp_tables[i]->is_genpd) {
233 dev_err(dev, "required-opp doesn't belong to genpd: %pOF\n",
235 goto free_required_tables;
241 free_required_tables:
242 _opp_table_free_required_tables(opp_table);
247 void _of_init_opp_table(struct opp_table *opp_table, struct device *dev,
250 struct device_node *np, *opp_np;
254 * Only required for backward compatibility with v1 bindings, but isn't
255 * harmful for other cases. And so we do it unconditionally.
257 np = of_node_get(dev->of_node);
261 if (!of_property_read_u32(np, "clock-latency", &val))
262 opp_table->clock_latency_ns_max = val;
263 of_property_read_u32(np, "voltage-tolerance",
264 &opp_table->voltage_tolerance_v1);
266 if (of_find_property(np, "#power-domain-cells", NULL))
267 opp_table->is_genpd = true;
269 /* Get OPP table node */
270 opp_np = _opp_of_get_opp_desc_node(np, index);
276 if (of_property_read_bool(opp_np, "opp-shared"))
277 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
279 opp_table->shared_opp = OPP_TABLE_ACCESS_EXCLUSIVE;
281 opp_table->np = opp_np;
283 _opp_table_alloc_required_tables(opp_table, dev, opp_np);
287 void _of_clear_opp_table(struct opp_table *opp_table)
289 _opp_table_free_required_tables(opp_table);
293 * Release all resources previously acquired with a call to
294 * _of_opp_alloc_required_opps().
296 void _of_opp_free_required_opps(struct opp_table *opp_table,
297 struct dev_pm_opp *opp)
299 struct dev_pm_opp **required_opps = opp->required_opps;
305 for (i = 0; i < opp_table->required_opp_count; i++) {
306 if (!required_opps[i])
309 /* Put the reference back */
310 dev_pm_opp_put(required_opps[i]);
313 kfree(required_opps);
314 opp->required_opps = NULL;
317 /* Populate all required OPPs which are part of "required-opps" list */
318 static int _of_opp_alloc_required_opps(struct opp_table *opp_table,
319 struct dev_pm_opp *opp)
321 struct dev_pm_opp **required_opps;
322 struct opp_table *required_table;
323 struct device_node *np;
324 int i, ret, count = opp_table->required_opp_count;
329 required_opps = kcalloc(count, sizeof(*required_opps), GFP_KERNEL);
333 opp->required_opps = required_opps;
335 for (i = 0; i < count; i++) {
336 required_table = opp_table->required_opp_tables[i];
338 np = of_parse_required_opp(opp->np, i);
341 goto free_required_opps;
344 required_opps[i] = _find_opp_of_np(required_table, np);
347 if (!required_opps[i]) {
348 pr_err("%s: Unable to find required OPP node: %pOF (%d)\n",
349 __func__, opp->np, i);
351 goto free_required_opps;
358 _of_opp_free_required_opps(opp_table, opp);
363 static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
364 struct device_node *np)
366 unsigned int count = opp_table->supported_hw_count;
370 if (!opp_table->supported_hw) {
372 * In the case that no supported_hw has been set by the
373 * platform but there is an opp-supported-hw value set for
374 * an OPP then the OPP should not be enabled as there is
375 * no way to see if the hardware supports it.
377 if (of_find_property(np, "opp-supported-hw", NULL))
384 ret = of_property_read_u32_index(np, "opp-supported-hw", count,
387 dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
388 __func__, count, ret);
392 /* Both of these are bitwise masks of the versions */
393 if (!(version & opp_table->supported_hw[count]))
400 static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
401 struct opp_table *opp_table)
403 u32 *microvolt, *microamp = NULL;
404 int supplies = opp_table->regulator_count, vcount, icount, ret, i, j;
405 struct property *prop = NULL;
408 /* Search for "opp-microvolt-<name>" */
409 if (opp_table->prop_name) {
410 snprintf(name, sizeof(name), "opp-microvolt-%s",
411 opp_table->prop_name);
412 prop = of_find_property(opp->np, name, NULL);
416 /* Search for "opp-microvolt" */
417 sprintf(name, "opp-microvolt");
418 prop = of_find_property(opp->np, name, NULL);
420 /* Missing property isn't a problem, but an invalid entry is */
422 if (unlikely(supplies == -1)) {
423 /* Initialize regulator_count */
424 opp_table->regulator_count = 0;
431 dev_err(dev, "%s: opp-microvolt missing although OPP managing regulators\n",
437 if (unlikely(supplies == -1)) {
438 /* Initialize regulator_count */
439 supplies = opp_table->regulator_count = 1;
440 } else if (unlikely(!supplies)) {
441 dev_err(dev, "%s: opp-microvolt wasn't expected\n", __func__);
445 vcount = of_property_count_u32_elems(opp->np, name);
447 dev_err(dev, "%s: Invalid %s property (%d)\n",
448 __func__, name, vcount);
452 /* There can be one or three elements per supply */
453 if (vcount != supplies && vcount != supplies * 3) {
454 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
455 __func__, name, vcount, supplies);
459 microvolt = kmalloc_array(vcount, sizeof(*microvolt), GFP_KERNEL);
463 ret = of_property_read_u32_array(opp->np, name, microvolt, vcount);
465 dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
470 /* Search for "opp-microamp-<name>" */
472 if (opp_table->prop_name) {
473 snprintf(name, sizeof(name), "opp-microamp-%s",
474 opp_table->prop_name);
475 prop = of_find_property(opp->np, name, NULL);
479 /* Search for "opp-microamp" */
480 sprintf(name, "opp-microamp");
481 prop = of_find_property(opp->np, name, NULL);
485 icount = of_property_count_u32_elems(opp->np, name);
487 dev_err(dev, "%s: Invalid %s property (%d)\n", __func__,
493 if (icount != supplies) {
494 dev_err(dev, "%s: Invalid number of elements in %s property (%d) with supplies (%d)\n",
495 __func__, name, icount, supplies);
500 microamp = kmalloc_array(icount, sizeof(*microamp), GFP_KERNEL);
506 ret = of_property_read_u32_array(opp->np, name, microamp,
509 dev_err(dev, "%s: error parsing %s: %d\n", __func__,
516 for (i = 0, j = 0; i < supplies; i++) {
517 opp->supplies[i].u_volt = microvolt[j++];
519 if (vcount == supplies) {
520 opp->supplies[i].u_volt_min = opp->supplies[i].u_volt;
521 opp->supplies[i].u_volt_max = opp->supplies[i].u_volt;
523 opp->supplies[i].u_volt_min = microvolt[j++];
524 opp->supplies[i].u_volt_max = microvolt[j++];
528 opp->supplies[i].u_amp = microamp[i];
540 * dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
542 * @dev: device pointer used to lookup OPP table.
544 * Free OPPs created using static entries present in DT.
546 void dev_pm_opp_of_remove_table(struct device *dev)
548 _dev_pm_opp_find_and_remove_table(dev);
550 EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
553 * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
554 * @opp_table: OPP table
555 * @dev: device for which we do this operation
558 * This function adds an opp definition to the opp table and returns status. The
559 * opp can be controlled using dev_pm_opp_enable/disable functions and may be
560 * removed by dev_pm_opp_remove.
566 * Duplicate OPPs (both freq and volt are same) and opp->available
567 * OR if the OPP is not supported by hardware.
569 * Freq are same and volt are different OR
570 * Duplicate OPPs (both freq and volt are same) and !opp->available
572 * Memory allocation failure
574 * Failed parsing the OPP node
576 static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
577 struct device *dev, struct device_node *np)
579 struct dev_pm_opp *new_opp;
583 bool rate_not_available = false;
585 new_opp = _opp_allocate(opp_table);
587 return ERR_PTR(-ENOMEM);
589 ret = of_property_read_u64(np, "opp-hz", &rate);
591 /* "opp-hz" is optional for devices like power domains. */
592 if (!opp_table->is_genpd) {
593 dev_err(dev, "%s: opp-hz not found\n", __func__);
597 rate_not_available = true;
600 * Rate is defined as an unsigned long in clk API, and so
601 * casting explicitly to its type. Must be fixed once rate is 64
602 * bit guaranteed in clk API.
604 new_opp->rate = (unsigned long)rate;
607 of_property_read_u32(np, "opp-level", &new_opp->level);
609 /* Check if the OPP supports hardware's hierarchy of versions or not */
610 if (!_opp_is_supported(dev, opp_table, np)) {
611 dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
615 new_opp->turbo = of_property_read_bool(np, "turbo-mode");
618 new_opp->dynamic = false;
619 new_opp->available = true;
621 ret = _of_opp_alloc_required_opps(opp_table, new_opp);
625 if (!of_property_read_u32(np, "clock-latency-ns", &val))
626 new_opp->clock_latency_ns = val;
628 ret = opp_parse_supplies(new_opp, dev, opp_table);
630 goto free_required_opps;
632 if (opp_table->is_genpd)
633 new_opp->pstate = pm_genpd_opp_to_performance_state(dev, new_opp);
635 ret = _opp_add(dev, new_opp, opp_table, rate_not_available);
637 /* Don't return error for duplicate OPPs */
640 goto free_required_opps;
643 /* OPP to select on device suspend */
644 if (of_property_read_bool(np, "opp-suspend")) {
645 if (opp_table->suspend_opp) {
646 dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n",
647 __func__, opp_table->suspend_opp->rate,
650 new_opp->suspend = true;
651 opp_table->suspend_opp = new_opp;
655 if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
656 opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
658 pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",
659 __func__, new_opp->turbo, new_opp->rate,
660 new_opp->supplies[0].u_volt, new_opp->supplies[0].u_volt_min,
661 new_opp->supplies[0].u_volt_max, new_opp->clock_latency_ns);
664 * Notify the changes in the availability of the operable
665 * frequency/voltage list.
667 blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
671 _of_opp_free_required_opps(opp_table, new_opp);
678 /* Initializes OPP tables based on new bindings */
679 static int _of_add_opp_table_v2(struct device *dev, struct opp_table *opp_table)
681 struct device_node *np;
682 int ret, count = 0, pstate_count = 0;
683 struct dev_pm_opp *opp;
685 /* OPP table is already initialized for the device */
686 if (opp_table->parsed_static_opps) {
687 kref_get(&opp_table->list_kref);
691 kref_init(&opp_table->list_kref);
693 /* We have opp-table node now, iterate over it and add OPPs */
694 for_each_available_child_of_node(opp_table->np, np) {
695 opp = _opp_add_static_v2(opp_table, dev, np);
698 dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
707 /* There should be one of more OPP defined */
708 if (WARN_ON(!count)) {
713 list_for_each_entry(opp, &opp_table->opp_list, node)
714 pstate_count += !!opp->pstate;
716 /* Either all or none of the nodes shall have performance state set */
717 if (pstate_count && pstate_count != count) {
718 dev_err(dev, "Not all nodes have performance state set (%d: %d)\n",
719 count, pstate_count);
725 opp_table->genpd_performance_state = true;
727 opp_table->parsed_static_opps = true;
732 _put_opp_list_kref(opp_table);
737 /* Initializes OPP tables based on old-deprecated bindings */
738 static int _of_add_opp_table_v1(struct device *dev, struct opp_table *opp_table)
740 const struct property *prop;
744 prop = of_find_property(dev->of_node, "operating-points", NULL);
751 * Each OPP is a set of tuples consisting of frequency and
752 * voltage like <freq-kHz vol-uV>.
754 nr = prop->length / sizeof(u32);
756 dev_err(dev, "%s: Invalid OPP table\n", __func__);
760 kref_init(&opp_table->list_kref);
764 unsigned long freq = be32_to_cpup(val++) * 1000;
765 unsigned long volt = be32_to_cpup(val++);
767 ret = _opp_add_v1(opp_table, dev, freq, volt, false);
769 dev_err(dev, "%s: Failed to add OPP %ld (%d)\n",
770 __func__, freq, ret);
771 _put_opp_list_kref(opp_table);
781 * dev_pm_opp_of_add_table() - Initialize opp table from device tree
782 * @dev: device pointer used to lookup OPP table.
784 * Register the initial OPP table with the OPP library for given device.
788 * Duplicate OPPs (both freq and volt are same) and opp->available
789 * -EEXIST Freq are same and volt are different OR
790 * Duplicate OPPs (both freq and volt are same) and !opp->available
791 * -ENOMEM Memory allocation failure
792 * -ENODEV when 'operating-points' property is not found or is invalid data
794 * -ENODATA when empty 'operating-points' property is found
795 * -EINVAL when invalid entries are found in opp-v2 table
797 int dev_pm_opp_of_add_table(struct device *dev)
799 struct opp_table *opp_table;
802 opp_table = dev_pm_opp_get_opp_table_indexed(dev, 0);
807 * OPPs have two version of bindings now. Also try the old (v1)
808 * bindings for backward compatibility with older dtbs.
811 ret = _of_add_opp_table_v2(dev, opp_table);
813 ret = _of_add_opp_table_v1(dev, opp_table);
816 dev_pm_opp_put_opp_table(opp_table);
820 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
823 * dev_pm_opp_of_add_table_indexed() - Initialize indexed opp table from device tree
824 * @dev: device pointer used to lookup OPP table.
825 * @index: Index number.
827 * Register the initial OPP table with the OPP library for given device only
828 * using the "operating-points-v2" property.
832 * Duplicate OPPs (both freq and volt are same) and opp->available
833 * -EEXIST Freq are same and volt are different OR
834 * Duplicate OPPs (both freq and volt are same) and !opp->available
835 * -ENOMEM Memory allocation failure
836 * -ENODEV when 'operating-points' property is not found or is invalid data
838 * -ENODATA when empty 'operating-points' property is found
839 * -EINVAL when invalid entries are found in opp-v2 table
841 int dev_pm_opp_of_add_table_indexed(struct device *dev, int index)
843 struct opp_table *opp_table;
848 * If only one phandle is present, then the same OPP table
849 * applies for all index requests.
851 count = of_count_phandle_with_args(dev->of_node,
852 "operating-points-v2", NULL);
857 opp_table = dev_pm_opp_get_opp_table_indexed(dev, index);
861 ret = _of_add_opp_table_v2(dev, opp_table);
863 dev_pm_opp_put_opp_table(opp_table);
867 EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table_indexed);
869 /* CPU device specific helpers */
872 * dev_pm_opp_of_cpumask_remove_table() - Removes OPP table for @cpumask
873 * @cpumask: cpumask for which OPP table needs to be removed
875 * This removes the OPP tables for CPUs present in the @cpumask.
876 * This should be used only to remove static entries created from DT.
878 void dev_pm_opp_of_cpumask_remove_table(const struct cpumask *cpumask)
880 _dev_pm_opp_cpumask_remove_table(cpumask, -1);
882 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
885 * dev_pm_opp_of_cpumask_add_table() - Adds OPP table for @cpumask
886 * @cpumask: cpumask for which OPP table needs to be added.
888 * This adds the OPP tables for CPUs present in the @cpumask.
890 int dev_pm_opp_of_cpumask_add_table(const struct cpumask *cpumask)
892 struct device *cpu_dev;
895 if (WARN_ON(cpumask_empty(cpumask)))
898 for_each_cpu(cpu, cpumask) {
899 cpu_dev = get_cpu_device(cpu);
901 pr_err("%s: failed to get cpu%d device\n", __func__,
907 ret = dev_pm_opp_of_add_table(cpu_dev);
910 * OPP may get registered dynamically, don't print error
913 pr_debug("%s: couldn't find opp table for cpu:%d, %d\n",
923 /* Free all other OPPs */
924 _dev_pm_opp_cpumask_remove_table(cpumask, cpu);
928 EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
931 * Works only for OPP v2 bindings.
933 * Returns -ENOENT if operating-points-v2 bindings aren't supported.
936 * dev_pm_opp_of_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with
937 * @cpu_dev using operating-points-v2
940 * @cpu_dev: CPU device for which we do this operation
941 * @cpumask: cpumask to update with information of sharing CPUs
943 * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
945 * Returns -ENOENT if operating-points-v2 isn't present for @cpu_dev.
947 int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev,
948 struct cpumask *cpumask)
950 struct device_node *np, *tmp_np, *cpu_np;
953 /* Get OPP descriptor node */
954 np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
956 dev_dbg(cpu_dev, "%s: Couldn't find opp node.\n", __func__);
960 cpumask_set_cpu(cpu_dev->id, cpumask);
962 /* OPPs are shared ? */
963 if (!of_property_read_bool(np, "opp-shared"))
966 for_each_possible_cpu(cpu) {
967 if (cpu == cpu_dev->id)
970 cpu_np = of_cpu_device_node_get(cpu);
972 dev_err(cpu_dev, "%s: failed to get cpu%d node\n",
978 /* Get OPP descriptor node */
979 tmp_np = _opp_of_get_opp_desc_node(cpu_np, 0);
982 pr_err("%pOF: Couldn't find opp node\n", cpu_np);
987 /* CPUs are sharing opp node */
989 cpumask_set_cpu(cpu, cpumask);
998 EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
1001 * of_get_required_opp_performance_state() - Search for required OPP and return its performance state.
1002 * @np: Node that contains the "required-opps" property.
1003 * @index: Index of the phandle to parse.
1005 * Returns the performance state of the OPP pointed out by the "required-opps"
1006 * property at @index in @np.
1008 * Return: Zero or positive performance state on success, otherwise negative
1011 int of_get_required_opp_performance_state(struct device_node *np, int index)
1013 struct dev_pm_opp *opp;
1014 struct device_node *required_np;
1015 struct opp_table *opp_table;
1016 int pstate = -EINVAL;
1018 required_np = of_parse_required_opp(np, index);
1022 opp_table = _find_table_of_opp_np(required_np);
1023 if (IS_ERR(opp_table)) {
1024 pr_err("%s: Failed to find required OPP table %pOF: %ld\n",
1025 __func__, np, PTR_ERR(opp_table));
1026 goto put_required_np;
1029 opp = _find_opp_of_np(opp_table, required_np);
1031 pstate = opp->pstate;
1032 dev_pm_opp_put(opp);
1035 dev_pm_opp_put_opp_table(opp_table);
1038 of_node_put(required_np);
1042 EXPORT_SYMBOL_GPL(of_get_required_opp_performance_state);
1045 * dev_pm_opp_get_of_node() - Gets the DT node corresponding to an opp
1046 * @opp: opp for which DT node has to be returned for
1048 * Return: DT node corresponding to the opp, else 0 on success.
1050 * The caller needs to put the node with of_node_put() after using it.
1052 struct device_node *dev_pm_opp_get_of_node(struct dev_pm_opp *opp)
1054 if (IS_ERR_OR_NULL(opp)) {
1055 pr_err("%s: Invalid parameters\n", __func__);
1059 return of_node_get(opp->np);
1061 EXPORT_SYMBOL_GPL(dev_pm_opp_get_of_node);
1064 * Callback function provided to the Energy Model framework upon registration.
1065 * This computes the power estimated by @CPU at @kHz if it is the frequency
1066 * of an existing OPP, or at the frequency of the first OPP above @kHz otherwise
1067 * (see dev_pm_opp_find_freq_ceil()). This function updates @kHz to the ceiled
1068 * frequency and @mW to the associated power. The power is estimated as
1069 * P = C * V^2 * f with C being the CPU's capacitance and V and f respectively
1070 * the voltage and frequency of the OPP.
1072 * Returns -ENODEV if the CPU device cannot be found, -EINVAL if the power
1073 * calculation failed because of missing parameters, 0 otherwise.
1075 static int __maybe_unused _get_cpu_power(unsigned long *mW, unsigned long *kHz,
1078 struct device *cpu_dev;
1079 struct dev_pm_opp *opp;
1080 struct device_node *np;
1081 unsigned long mV, Hz;
1086 cpu_dev = get_cpu_device(cpu);
1090 np = of_node_get(cpu_dev->of_node);
1094 ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1100 opp = dev_pm_opp_find_freq_ceil(cpu_dev, &Hz);
1104 mV = dev_pm_opp_get_voltage(opp) / 1000;
1105 dev_pm_opp_put(opp);
1109 tmp = (u64)cap * mV * mV * (Hz / 1000000);
1110 do_div(tmp, 1000000000);
1112 *mW = (unsigned long)tmp;
1119 * dev_pm_opp_of_register_em() - Attempt to register an Energy Model
1120 * @cpus : CPUs for which an Energy Model has to be registered
1122 * This checks whether the "dynamic-power-coefficient" devicetree property has
1123 * been specified, and tries to register an Energy Model with it if it has.
1125 void dev_pm_opp_of_register_em(struct cpumask *cpus)
1127 struct em_data_callback em_cb = EM_DATA_CB(_get_cpu_power);
1128 int ret, nr_opp, cpu = cpumask_first(cpus);
1129 struct device *cpu_dev;
1130 struct device_node *np;
1133 cpu_dev = get_cpu_device(cpu);
1137 nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
1141 np = of_node_get(cpu_dev->of_node);
1146 * Register an EM only if the 'dynamic-power-coefficient' property is
1147 * set in devicetree. It is assumed the voltage values are known if that
1148 * property is set since it is useless otherwise. If voltages are not
1149 * known, just let the EM registration fail with an error to alert the
1150 * user about the inconsistent configuration.
1152 ret = of_property_read_u32(np, "dynamic-power-coefficient", &cap);
1157 em_register_perf_domain(cpus, nr_opp, &em_cb);
1159 EXPORT_SYMBOL_GPL(dev_pm_opp_of_register_em);