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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * System Control and Power Interface (SCMI) based CPUFreq Interface driver
4 *
5 * Copyright (C) 2018-2021 ARM Ltd.
6 * Sudeep Holla <sudeep.holla@arm.com>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/clk-provider.h>
12#include <linux/cpu.h>
13#include <linux/cpufreq.h>
14#include <linux/cpumask.h>
15#include <linux/energy_model.h>
16#include <linux/export.h>
17#include <linux/module.h>
18#include <linux/pm_opp.h>
19#include <linux/slab.h>
20#include <linux/scmi_protocol.h>
21#include <linux/types.h>
22#include <linux/units.h>
23
24struct scmi_data {
25 int domain_id;
26 int nr_opp;
27 struct device *cpu_dev;
28 cpumask_var_t opp_shared_cpus;
29};
30
31static struct scmi_protocol_handle *ph;
32static const struct scmi_perf_proto_ops *perf_ops;
33static struct cpufreq_driver scmi_cpufreq_driver;
34
35static unsigned int scmi_cpufreq_get_rate(unsigned int cpu)
36{
37 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
38 struct scmi_data *priv = policy->driver_data;
39 unsigned long rate;
40 int ret;
41
42 ret = perf_ops->freq_get(ph, priv->domain_id, &rate, false);
43 if (ret)
44 return 0;
45 return rate / 1000;
46}
47
48/*
49 * perf_ops->freq_set is not a synchronous, the actual OPP change will
50 * happen asynchronously and can get notified if the events are
51 * subscribed for by the SCMI firmware
52 */
53static int
54scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
55{
56 struct scmi_data *priv = policy->driver_data;
57 u64 freq = policy->freq_table[index].frequency;
58
59 return perf_ops->freq_set(ph, priv->domain_id, freq * 1000, false);
60}
61
62static unsigned int scmi_cpufreq_fast_switch(struct cpufreq_policy *policy,
63 unsigned int target_freq)
64{
65 struct scmi_data *priv = policy->driver_data;
66 unsigned long freq = target_freq;
67
68 if (!perf_ops->freq_set(ph, priv->domain_id, freq * 1000, true))
69 return target_freq;
70
71 return 0;
72}
73
74static int scmi_cpu_domain_id(struct device *cpu_dev)
75{
76 struct device_node *np = cpu_dev->of_node;
77 struct of_phandle_args domain_id;
78 int index;
79
80 if (of_parse_phandle_with_args(np, "clocks", "#clock-cells", 0,
81 &domain_id)) {
82 /* Find the corresponding index for power-domain "perf". */
83 index = of_property_match_string(np, "power-domain-names",
84 "perf");
85 if (index < 0)
86 return -EINVAL;
87
88 if (of_parse_phandle_with_args(np, "power-domains",
89 "#power-domain-cells", index,
90 &domain_id))
91 return -EINVAL;
92 }
93
94 return domain_id.args[0];
95}
96
97static int
98scmi_get_sharing_cpus(struct device *cpu_dev, int domain,
99 struct cpumask *cpumask)
100{
101 int cpu, tdomain;
102 struct device *tcpu_dev;
103
104 for_each_possible_cpu(cpu) {
105 if (cpu == cpu_dev->id)
106 continue;
107
108 tcpu_dev = get_cpu_device(cpu);
109 if (!tcpu_dev)
110 continue;
111
112 tdomain = scmi_cpu_domain_id(tcpu_dev);
113 if (tdomain == domain)
114 cpumask_set_cpu(cpu, cpumask);
115 }
116
117 return 0;
118}
119
120static int __maybe_unused
121scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power,
122 unsigned long *KHz)
123{
124 enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
125 unsigned long Hz;
126 int ret, domain;
127
128 domain = scmi_cpu_domain_id(cpu_dev);
129 if (domain < 0)
130 return domain;
131
132 /* Get the power cost of the performance domain. */
133 Hz = *KHz * 1000;
134 ret = perf_ops->est_power_get(ph, domain, &Hz, power);
135 if (ret)
136 return ret;
137
138 /* Convert the power to uW if it is mW (ignore bogoW) */
139 if (power_scale == SCMI_POWER_MILLIWATTS)
140 *power *= MICROWATT_PER_MILLIWATT;
141
142 /* The EM framework specifies the frequency in KHz. */
143 *KHz = Hz / 1000;
144
145 return 0;
146}
147
148static int
149scmi_get_rate_limit(u32 domain, bool has_fast_switch)
150{
151 int ret, rate_limit;
152
153 if (has_fast_switch) {
154 /*
155 * Fast channels are used whenever available,
156 * so use their rate_limit value if populated.
157 */
158 ret = perf_ops->fast_switch_rate_limit(ph, domain,
159 &rate_limit);
160 if (!ret && rate_limit)
161 return rate_limit;
162 }
163
164 ret = perf_ops->rate_limit_get(ph, domain, &rate_limit);
165 if (ret)
166 return 0;
167
168 return rate_limit;
169}
170
171static struct freq_attr *scmi_cpufreq_hw_attr[] = {
172 &cpufreq_freq_attr_scaling_available_freqs,
173 NULL,
174 NULL,
175};
176
177static int scmi_cpufreq_init(struct cpufreq_policy *policy)
178{
179 int ret, nr_opp, domain;
180 unsigned int latency;
181 struct device *cpu_dev;
182 struct scmi_data *priv;
183 struct cpufreq_frequency_table *freq_table;
184
185 cpu_dev = get_cpu_device(policy->cpu);
186 if (!cpu_dev) {
187 pr_err("failed to get cpu%d device\n", policy->cpu);
188 return -ENODEV;
189 }
190
191 domain = scmi_cpu_domain_id(cpu_dev);
192 if (domain < 0)
193 return domain;
194
195 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
196 if (!priv)
197 return -ENOMEM;
198
199 if (!zalloc_cpumask_var(&priv->opp_shared_cpus, GFP_KERNEL)) {
200 ret = -ENOMEM;
201 goto out_free_priv;
202 }
203
204 /* Obtain CPUs that share SCMI performance controls */
205 ret = scmi_get_sharing_cpus(cpu_dev, domain, policy->cpus);
206 if (ret) {
207 dev_warn(cpu_dev, "failed to get sharing cpumask\n");
208 goto out_free_cpumask;
209 }
210
211 /*
212 * Obtain CPUs that share performance levels.
213 * The OPP 'sharing cpus' info may come from DT through an empty opp
214 * table and opp-shared.
215 */
216 ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, priv->opp_shared_cpus);
217 if (ret || cpumask_empty(priv->opp_shared_cpus)) {
218 /*
219 * Either opp-table is not set or no opp-shared was found.
220 * Use the CPU mask from SCMI to designate CPUs sharing an OPP
221 * table.
222 */
223 cpumask_copy(priv->opp_shared_cpus, policy->cpus);
224 }
225
226 /*
227 * A previous CPU may have marked OPPs as shared for a few CPUs, based on
228 * what OPP core provided. If the current CPU is part of those few, then
229 * there is no need to add OPPs again.
230 */
231 nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
232 if (nr_opp <= 0) {
233 ret = perf_ops->device_opps_add(ph, cpu_dev, domain);
234 if (ret) {
235 dev_warn(cpu_dev, "failed to add opps to the device\n");
236 goto out_free_cpumask;
237 }
238
239 nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
240 if (nr_opp <= 0) {
241 dev_err(cpu_dev, "%s: No OPPs for this device: %d\n",
242 __func__, nr_opp);
243
244 ret = -ENODEV;
245 goto out_free_opp;
246 }
247
248 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, priv->opp_shared_cpus);
249 if (ret) {
250 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
251 __func__, ret);
252
253 goto out_free_opp;
254 }
255
256 priv->nr_opp = nr_opp;
257 }
258
259 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
260 if (ret) {
261 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
262 goto out_free_opp;
263 }
264
265 priv->cpu_dev = cpu_dev;
266 priv->domain_id = domain;
267
268 policy->driver_data = priv;
269 policy->freq_table = freq_table;
270
271 /* SCMI allows DVFS request for any domain from any CPU */
272 policy->dvfs_possible_from_any_cpu = true;
273
274 latency = perf_ops->transition_latency_get(ph, domain);
275 if (!latency)
276 latency = CPUFREQ_ETERNAL;
277
278 policy->cpuinfo.transition_latency = latency;
279
280 policy->fast_switch_possible =
281 perf_ops->fast_switch_possible(ph, domain);
282
283 policy->transition_delay_us =
284 scmi_get_rate_limit(domain, policy->fast_switch_possible);
285
286 if (policy_has_boost_freq(policy)) {
287 ret = cpufreq_enable_boost_support();
288 if (ret) {
289 dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);
290 goto out_free_table;
291 } else {
292 scmi_cpufreq_hw_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
293 scmi_cpufreq_driver.boost_enabled = true;
294 }
295 }
296
297 return 0;
298
299out_free_table:
300 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
301out_free_opp:
302 dev_pm_opp_remove_all_dynamic(cpu_dev);
303
304out_free_cpumask:
305 free_cpumask_var(priv->opp_shared_cpus);
306
307out_free_priv:
308 kfree(priv);
309
310 return ret;
311}
312
313static void scmi_cpufreq_exit(struct cpufreq_policy *policy)
314{
315 struct scmi_data *priv = policy->driver_data;
316
317 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
318 dev_pm_opp_remove_all_dynamic(priv->cpu_dev);
319 free_cpumask_var(priv->opp_shared_cpus);
320 kfree(priv);
321}
322
323static void scmi_cpufreq_register_em(struct cpufreq_policy *policy)
324{
325 struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power);
326 enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
327 struct scmi_data *priv = policy->driver_data;
328 bool em_power_scale = false;
329
330 /*
331 * This callback will be called for each policy, but we don't need to
332 * register with EM every time. Despite not being part of the same
333 * policy, some CPUs may still share their perf-domains, and a CPU from
334 * another policy may already have registered with EM on behalf of CPUs
335 * of this policy.
336 */
337 if (!priv->nr_opp)
338 return;
339
340 if (power_scale == SCMI_POWER_MILLIWATTS
341 || power_scale == SCMI_POWER_MICROWATTS)
342 em_power_scale = true;
343
344 em_dev_register_perf_domain(get_cpu_device(policy->cpu), priv->nr_opp,
345 &em_cb, priv->opp_shared_cpus,
346 em_power_scale);
347}
348
349static struct cpufreq_driver scmi_cpufreq_driver = {
350 .name = "scmi",
351 .flags = CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
352 CPUFREQ_NEED_INITIAL_FREQ_CHECK |
353 CPUFREQ_IS_COOLING_DEV,
354 .verify = cpufreq_generic_frequency_table_verify,
355 .attr = scmi_cpufreq_hw_attr,
356 .target_index = scmi_cpufreq_set_target,
357 .fast_switch = scmi_cpufreq_fast_switch,
358 .get = scmi_cpufreq_get_rate,
359 .init = scmi_cpufreq_init,
360 .exit = scmi_cpufreq_exit,
361 .register_em = scmi_cpufreq_register_em,
362};
363
364static int scmi_cpufreq_probe(struct scmi_device *sdev)
365{
366 int ret;
367 struct device *dev = &sdev->dev;
368 const struct scmi_handle *handle;
369
370 handle = sdev->handle;
371
372 if (!handle)
373 return -ENODEV;
374
375 perf_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_PERF, &ph);
376 if (IS_ERR(perf_ops))
377 return PTR_ERR(perf_ops);
378
379#ifdef CONFIG_COMMON_CLK
380 /* dummy clock provider as needed by OPP if clocks property is used */
381 if (of_property_present(dev->of_node, "#clock-cells")) {
382 ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, NULL);
383 if (ret)
384 return dev_err_probe(dev, ret, "%s: registering clock provider failed\n", __func__);
385 }
386#endif
387
388 ret = cpufreq_register_driver(&scmi_cpufreq_driver);
389 if (ret) {
390 dev_err(dev, "%s: registering cpufreq failed, err: %d\n",
391 __func__, ret);
392 }
393
394 return ret;
395}
396
397static void scmi_cpufreq_remove(struct scmi_device *sdev)
398{
399 cpufreq_unregister_driver(&scmi_cpufreq_driver);
400}
401
402static const struct scmi_device_id scmi_id_table[] = {
403 { SCMI_PROTOCOL_PERF, "cpufreq" },
404 { },
405};
406MODULE_DEVICE_TABLE(scmi, scmi_id_table);
407
408static struct scmi_driver scmi_cpufreq_drv = {
409 .name = "scmi-cpufreq",
410 .probe = scmi_cpufreq_probe,
411 .remove = scmi_cpufreq_remove,
412 .id_table = scmi_id_table,
413};
414module_scmi_driver(scmi_cpufreq_drv);
415
416MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
417MODULE_DESCRIPTION("ARM SCMI CPUFreq interface driver");
418MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * System Control and Power Interface (SCMI) based CPUFreq Interface driver
4 *
5 * Copyright (C) 2018-2021 ARM Ltd.
6 * Sudeep Holla <sudeep.holla@arm.com>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/clk-provider.h>
12#include <linux/cpu.h>
13#include <linux/cpufreq.h>
14#include <linux/cpumask.h>
15#include <linux/energy_model.h>
16#include <linux/export.h>
17#include <linux/module.h>
18#include <linux/pm_opp.h>
19#include <linux/slab.h>
20#include <linux/scmi_protocol.h>
21#include <linux/types.h>
22#include <linux/units.h>
23
24struct scmi_data {
25 int domain_id;
26 int nr_opp;
27 struct device *cpu_dev;
28 cpumask_var_t opp_shared_cpus;
29};
30
31static struct scmi_protocol_handle *ph;
32static const struct scmi_perf_proto_ops *perf_ops;
33
34static unsigned int scmi_cpufreq_get_rate(unsigned int cpu)
35{
36 struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
37 struct scmi_data *priv = policy->driver_data;
38 unsigned long rate;
39 int ret;
40
41 ret = perf_ops->freq_get(ph, priv->domain_id, &rate, false);
42 if (ret)
43 return 0;
44 return rate / 1000;
45}
46
47/*
48 * perf_ops->freq_set is not a synchronous, the actual OPP change will
49 * happen asynchronously and can get notified if the events are
50 * subscribed for by the SCMI firmware
51 */
52static int
53scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
54{
55 struct scmi_data *priv = policy->driver_data;
56 u64 freq = policy->freq_table[index].frequency;
57
58 return perf_ops->freq_set(ph, priv->domain_id, freq * 1000, false);
59}
60
61static unsigned int scmi_cpufreq_fast_switch(struct cpufreq_policy *policy,
62 unsigned int target_freq)
63{
64 struct scmi_data *priv = policy->driver_data;
65
66 if (!perf_ops->freq_set(ph, priv->domain_id,
67 target_freq * 1000, true))
68 return target_freq;
69
70 return 0;
71}
72
73static int
74scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
75{
76 int cpu, domain, tdomain;
77 struct device *tcpu_dev;
78
79 domain = perf_ops->device_domain_id(cpu_dev);
80 if (domain < 0)
81 return domain;
82
83 for_each_possible_cpu(cpu) {
84 if (cpu == cpu_dev->id)
85 continue;
86
87 tcpu_dev = get_cpu_device(cpu);
88 if (!tcpu_dev)
89 continue;
90
91 tdomain = perf_ops->device_domain_id(tcpu_dev);
92 if (tdomain == domain)
93 cpumask_set_cpu(cpu, cpumask);
94 }
95
96 return 0;
97}
98
99static int __maybe_unused
100scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power,
101 unsigned long *KHz)
102{
103 enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
104 unsigned long Hz;
105 int ret, domain;
106
107 domain = perf_ops->device_domain_id(cpu_dev);
108 if (domain < 0)
109 return domain;
110
111 /* Get the power cost of the performance domain. */
112 Hz = *KHz * 1000;
113 ret = perf_ops->est_power_get(ph, domain, &Hz, power);
114 if (ret)
115 return ret;
116
117 /* Convert the power to uW if it is mW (ignore bogoW) */
118 if (power_scale == SCMI_POWER_MILLIWATTS)
119 *power *= MICROWATT_PER_MILLIWATT;
120
121 /* The EM framework specifies the frequency in KHz. */
122 *KHz = Hz / 1000;
123
124 return 0;
125}
126
127static int scmi_cpufreq_init(struct cpufreq_policy *policy)
128{
129 int ret, nr_opp;
130 unsigned int latency;
131 struct device *cpu_dev;
132 struct scmi_data *priv;
133 struct cpufreq_frequency_table *freq_table;
134
135 cpu_dev = get_cpu_device(policy->cpu);
136 if (!cpu_dev) {
137 pr_err("failed to get cpu%d device\n", policy->cpu);
138 return -ENODEV;
139 }
140
141 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
142 if (!priv)
143 return -ENOMEM;
144
145 if (!zalloc_cpumask_var(&priv->opp_shared_cpus, GFP_KERNEL)) {
146 ret = -ENOMEM;
147 goto out_free_priv;
148 }
149
150 /* Obtain CPUs that share SCMI performance controls */
151 ret = scmi_get_sharing_cpus(cpu_dev, policy->cpus);
152 if (ret) {
153 dev_warn(cpu_dev, "failed to get sharing cpumask\n");
154 goto out_free_cpumask;
155 }
156
157 /*
158 * Obtain CPUs that share performance levels.
159 * The OPP 'sharing cpus' info may come from DT through an empty opp
160 * table and opp-shared.
161 */
162 ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, priv->opp_shared_cpus);
163 if (ret || cpumask_empty(priv->opp_shared_cpus)) {
164 /*
165 * Either opp-table is not set or no opp-shared was found.
166 * Use the CPU mask from SCMI to designate CPUs sharing an OPP
167 * table.
168 */
169 cpumask_copy(priv->opp_shared_cpus, policy->cpus);
170 }
171
172 /*
173 * A previous CPU may have marked OPPs as shared for a few CPUs, based on
174 * what OPP core provided. If the current CPU is part of those few, then
175 * there is no need to add OPPs again.
176 */
177 nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
178 if (nr_opp <= 0) {
179 ret = perf_ops->device_opps_add(ph, cpu_dev);
180 if (ret) {
181 dev_warn(cpu_dev, "failed to add opps to the device\n");
182 goto out_free_cpumask;
183 }
184
185 nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
186 if (nr_opp <= 0) {
187 dev_err(cpu_dev, "%s: No OPPs for this device: %d\n",
188 __func__, nr_opp);
189
190 ret = -ENODEV;
191 goto out_free_opp;
192 }
193
194 ret = dev_pm_opp_set_sharing_cpus(cpu_dev, priv->opp_shared_cpus);
195 if (ret) {
196 dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
197 __func__, ret);
198
199 goto out_free_opp;
200 }
201
202 priv->nr_opp = nr_opp;
203 }
204
205 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
206 if (ret) {
207 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
208 goto out_free_opp;
209 }
210
211 priv->cpu_dev = cpu_dev;
212 priv->domain_id = perf_ops->device_domain_id(cpu_dev);
213
214 policy->driver_data = priv;
215 policy->freq_table = freq_table;
216
217 /* SCMI allows DVFS request for any domain from any CPU */
218 policy->dvfs_possible_from_any_cpu = true;
219
220 latency = perf_ops->transition_latency_get(ph, cpu_dev);
221 if (!latency)
222 latency = CPUFREQ_ETERNAL;
223
224 policy->cpuinfo.transition_latency = latency;
225
226 policy->fast_switch_possible =
227 perf_ops->fast_switch_possible(ph, cpu_dev);
228
229 return 0;
230
231out_free_opp:
232 dev_pm_opp_remove_all_dynamic(cpu_dev);
233
234out_free_cpumask:
235 free_cpumask_var(priv->opp_shared_cpus);
236
237out_free_priv:
238 kfree(priv);
239
240 return ret;
241}
242
243static int scmi_cpufreq_exit(struct cpufreq_policy *policy)
244{
245 struct scmi_data *priv = policy->driver_data;
246
247 dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
248 dev_pm_opp_remove_all_dynamic(priv->cpu_dev);
249 free_cpumask_var(priv->opp_shared_cpus);
250 kfree(priv);
251
252 return 0;
253}
254
255static void scmi_cpufreq_register_em(struct cpufreq_policy *policy)
256{
257 struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power);
258 enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
259 struct scmi_data *priv = policy->driver_data;
260 bool em_power_scale = false;
261
262 /*
263 * This callback will be called for each policy, but we don't need to
264 * register with EM every time. Despite not being part of the same
265 * policy, some CPUs may still share their perf-domains, and a CPU from
266 * another policy may already have registered with EM on behalf of CPUs
267 * of this policy.
268 */
269 if (!priv->nr_opp)
270 return;
271
272 if (power_scale == SCMI_POWER_MILLIWATTS
273 || power_scale == SCMI_POWER_MICROWATTS)
274 em_power_scale = true;
275
276 em_dev_register_perf_domain(get_cpu_device(policy->cpu), priv->nr_opp,
277 &em_cb, priv->opp_shared_cpus,
278 em_power_scale);
279}
280
281static struct cpufreq_driver scmi_cpufreq_driver = {
282 .name = "scmi",
283 .flags = CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
284 CPUFREQ_NEED_INITIAL_FREQ_CHECK |
285 CPUFREQ_IS_COOLING_DEV,
286 .verify = cpufreq_generic_frequency_table_verify,
287 .attr = cpufreq_generic_attr,
288 .target_index = scmi_cpufreq_set_target,
289 .fast_switch = scmi_cpufreq_fast_switch,
290 .get = scmi_cpufreq_get_rate,
291 .init = scmi_cpufreq_init,
292 .exit = scmi_cpufreq_exit,
293 .register_em = scmi_cpufreq_register_em,
294};
295
296static int scmi_cpufreq_probe(struct scmi_device *sdev)
297{
298 int ret;
299 struct device *dev = &sdev->dev;
300 const struct scmi_handle *handle;
301
302 handle = sdev->handle;
303
304 if (!handle)
305 return -ENODEV;
306
307 perf_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_PERF, &ph);
308 if (IS_ERR(perf_ops))
309 return PTR_ERR(perf_ops);
310
311#ifdef CONFIG_COMMON_CLK
312 /* dummy clock provider as needed by OPP if clocks property is used */
313 if (of_find_property(dev->of_node, "#clock-cells", NULL))
314 devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, NULL);
315#endif
316
317 ret = cpufreq_register_driver(&scmi_cpufreq_driver);
318 if (ret) {
319 dev_err(dev, "%s: registering cpufreq failed, err: %d\n",
320 __func__, ret);
321 }
322
323 return ret;
324}
325
326static void scmi_cpufreq_remove(struct scmi_device *sdev)
327{
328 cpufreq_unregister_driver(&scmi_cpufreq_driver);
329}
330
331static const struct scmi_device_id scmi_id_table[] = {
332 { SCMI_PROTOCOL_PERF, "cpufreq" },
333 { },
334};
335MODULE_DEVICE_TABLE(scmi, scmi_id_table);
336
337static struct scmi_driver scmi_cpufreq_drv = {
338 .name = "scmi-cpufreq",
339 .probe = scmi_cpufreq_probe,
340 .remove = scmi_cpufreq_remove,
341 .id_table = scmi_id_table,
342};
343module_scmi_driver(scmi_cpufreq_drv);
344
345MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
346MODULE_DESCRIPTION("ARM SCMI CPUFreq interface driver");
347MODULE_LICENSE("GPL v2");