[linux-block.git] / drivers / cpufreq / scmi-cpufreq.c

// SPDX-License-Identifier: GPL-2.0
/*
 * System Control and Power Interface (SCMI) based CPUFreq Interface driver
 *
 * Copyright (C) 2018-2021 ARM Ltd.
 * Sudeep Holla <sudeep.holla@arm.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/clk-provider.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/energy_model.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/pm_opp.h>
#include <linux/slab.h>
#include <linux/scmi_protocol.h>
#include <linux/types.h>
#include <linux/units.h>

struct scmi_data {
	int domain_id;
	int nr_opp;
	struct device *cpu_dev;
	cpumask_var_t opp_shared_cpus;
};

static struct scmi_protocol_handle *ph;
static const struct scmi_perf_proto_ops *perf_ops;

static unsigned int scmi_cpufreq_get_rate(unsigned int cpu)
{
	struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
	struct scmi_data *priv = policy->driver_data;
	unsigned long rate;
	int ret;

	ret = perf_ops->freq_get(ph, priv->domain_id, &rate, false);
	if (ret)
		return 0;
	return rate / 1000;
}

/*
 * perf_ops->freq_set is not a synchronous, the actual OPP change will
 * happen asynchronously and can get notified if the events are
 * subscribed for by the SCMI firmware
 */
static int
scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
{
	struct scmi_data *priv = policy->driver_data;
	u64 freq = policy->freq_table[index].frequency;

	return perf_ops->freq_set(ph, priv->domain_id, freq * 1000, false);
}

static unsigned int scmi_cpufreq_fast_switch(struct cpufreq_policy *policy,
					     unsigned int target_freq)
{
	struct scmi_data *priv = policy->driver_data;

	if (!perf_ops->freq_set(ph, priv->domain_id,
				target_freq * 1000, true))
		return target_freq;

	return 0;
}

static int
scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
{
	int cpu, domain, tdomain;
	struct device *tcpu_dev;

	domain = perf_ops->device_domain_id(cpu_dev);
	if (domain < 0)
		return domain;

	for_each_possible_cpu(cpu) {
		if (cpu == cpu_dev->id)
			continue;

		tcpu_dev = get_cpu_device(cpu);
		if (!tcpu_dev)
			continue;

		tdomain = perf_ops->device_domain_id(tcpu_dev);
		if (tdomain == domain)
			cpumask_set_cpu(cpu, cpumask);
	}

	return 0;
}

static int __maybe_unused
scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power,
		   unsigned long *KHz)
{
	enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
	unsigned long Hz;
	int ret, domain;

	domain = perf_ops->device_domain_id(cpu_dev);
	if (domain < 0)
		return domain;

	/* Get the power cost of the performance domain. */
	Hz = *KHz * 1000;
	ret = perf_ops->est_power_get(ph, domain, &Hz, power);
	if (ret)
		return ret;

	/* Convert the power to uW if it is mW (ignore bogoW) */
	if (power_scale == SCMI_POWER_MILLIWATTS)
		*power *= MICROWATT_PER_MILLIWATT;

	/* The EM framework specifies the frequency in KHz. */
	*KHz = Hz / 1000;

	return 0;
}

static int scmi_cpufreq_init(struct cpufreq_policy *policy)
{
	int ret, nr_opp;
	unsigned int latency;
	struct device *cpu_dev;
	struct scmi_data *priv;
	struct cpufreq_frequency_table *freq_table;

	cpu_dev = get_cpu_device(policy->cpu);
	if (!cpu_dev) {
		pr_err("failed to get cpu%d device\n", policy->cpu);
		return -ENODEV;
	}

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	if (!zalloc_cpumask_var(&priv->opp_shared_cpus, GFP_KERNEL)) {
		ret = -ENOMEM;
		goto out_free_priv;
	}

	/* Obtain CPUs that share SCMI performance controls */
	ret = scmi_get_sharing_cpus(cpu_dev, policy->cpus);
	if (ret) {
		dev_warn(cpu_dev, "failed to get sharing cpumask\n");
		goto out_free_cpumask;
	}

	/*
	 * Obtain CPUs that share performance levels.
	 * The OPP 'sharing cpus' info may come from DT through an empty opp
	 * table and opp-shared.
	 */
	ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, priv->opp_shared_cpus);
	if (ret || cpumask_empty(priv->opp_shared_cpus)) {
		/*
		 * Either opp-table is not set or no opp-shared was found.
		 * Use the CPU mask from SCMI to designate CPUs sharing an OPP
		 * table.
		 */
		cpumask_copy(priv->opp_shared_cpus, policy->cpus);
	}

	 /*
	  * A previous CPU may have marked OPPs as shared for a few CPUs, based on
	  * what OPP core provided. If the current CPU is part of those few, then
	  * there is no need to add OPPs again.
	  */
	nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
	if (nr_opp <= 0) {
		ret = perf_ops->device_opps_add(ph, cpu_dev);
		if (ret) {
			dev_warn(cpu_dev, "failed to add opps to the device\n");
			goto out_free_cpumask;
		}

		nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
		if (nr_opp <= 0) {
			dev_err(cpu_dev, "%s: No OPPs for this device: %d\n",
				__func__, nr_opp);

			ret = -ENODEV;
			goto out_free_opp;
		}

		ret = dev_pm_opp_set_sharing_cpus(cpu_dev, priv->opp_shared_cpus);
		if (ret) {
			dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
				__func__, ret);

			goto out_free_opp;
		}

		priv->nr_opp = nr_opp;
	}

	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
	if (ret) {
		dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
		goto out_free_opp;
	}

	priv->cpu_dev = cpu_dev;
	priv->domain_id = perf_ops->device_domain_id(cpu_dev);

	policy->driver_data = priv;
	policy->freq_table = freq_table;

	/* SCMI allows DVFS request for any domain from any CPU */
	policy->dvfs_possible_from_any_cpu = true;

	latency = perf_ops->transition_latency_get(ph, cpu_dev);
	if (!latency)
		latency = CPUFREQ_ETERNAL;

	policy->cpuinfo.transition_latency = latency;

	policy->fast_switch_possible =
		perf_ops->fast_switch_possible(ph, cpu_dev);

	return 0;

out_free_opp:
	dev_pm_opp_remove_all_dynamic(cpu_dev);

out_free_cpumask:
	free_cpumask_var(priv->opp_shared_cpus);

out_free_priv:
	kfree(priv);

	return ret;
}

static int scmi_cpufreq_exit(struct cpufreq_policy *policy)
{
	struct scmi_data *priv = policy->driver_data;

	dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
	dev_pm_opp_remove_all_dynamic(priv->cpu_dev);
	free_cpumask_var(priv->opp_shared_cpus);
	kfree(priv);

	return 0;
}

static void scmi_cpufreq_register_em(struct cpufreq_policy *policy)
{
	struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power);
	enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
	struct scmi_data *priv = policy->driver_data;
	bool em_power_scale = false;

	/*
	 * This callback will be called for each policy, but we don't need to
	 * register with EM every time. Despite not being part of the same
	 * policy, some CPUs may still share their perf-domains, and a CPU from
	 * another policy may already have registered with EM on behalf of CPUs
	 * of this policy.
	 */
	if (!priv->nr_opp)
		return;

	if (power_scale == SCMI_POWER_MILLIWATTS
	    || power_scale == SCMI_POWER_MICROWATTS)
		em_power_scale = true;

	em_dev_register_perf_domain(get_cpu_device(policy->cpu), priv->nr_opp,
				    &em_cb, priv->opp_shared_cpus,
				    em_power_scale);
}

static struct cpufreq_driver scmi_cpufreq_driver = {
	.name	= "scmi",
	.flags	= CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
		  CPUFREQ_NEED_INITIAL_FREQ_CHECK |
		  CPUFREQ_IS_COOLING_DEV,
	.verify	= cpufreq_generic_frequency_table_verify,
	.attr	= cpufreq_generic_attr,
	.target_index	= scmi_cpufreq_set_target,
	.fast_switch	= scmi_cpufreq_fast_switch,
	.get	= scmi_cpufreq_get_rate,
	.init	= scmi_cpufreq_init,
	.exit	= scmi_cpufreq_exit,
	.register_em	= scmi_cpufreq_register_em,
};

static int scmi_cpufreq_probe(struct scmi_device *sdev)
{
	int ret;
	struct device *dev = &sdev->dev;
	const struct scmi_handle *handle;

	handle = sdev->handle;

	if (!handle)
		return -ENODEV;

	perf_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_PERF, &ph);
	if (IS_ERR(perf_ops))
		return PTR_ERR(perf_ops);

#ifdef CONFIG_COMMON_CLK
	/* dummy clock provider as needed by OPP if clocks property is used */
	if (of_property_present(dev->of_node, "#clock-cells"))
		devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, NULL);
#endif

	ret = cpufreq_register_driver(&scmi_cpufreq_driver);
	if (ret) {
		dev_err(dev, "%s: registering cpufreq failed, err: %d\n",
			__func__, ret);
	}

	return ret;
}

static void scmi_cpufreq_remove(struct scmi_device *sdev)
{
	cpufreq_unregister_driver(&scmi_cpufreq_driver);
}

static const struct scmi_device_id scmi_id_table[] = {
	{ SCMI_PROTOCOL_PERF, "cpufreq" },
	{ },
};
MODULE_DEVICE_TABLE(scmi, scmi_id_table);

static struct scmi_driver scmi_cpufreq_drv = {
	.name		= "scmi-cpufreq",
	.probe		= scmi_cpufreq_probe,
	.remove		= scmi_cpufreq_remove,
	.id_table	= scmi_id_table,
};
module_scmi_driver(scmi_cpufreq_drv);

MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
MODULE_DESCRIPTION("ARM SCMI CPUFreq interface driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
99d6bdf3 SH	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* System Control and Power Interface (SCMI) based CPUFreq Interface driver
	4	*
eb1d35c6	5	* Copyright (C) 2018-2021 ARM Ltd.
99d6bdf3 SH	6	* Sudeep Holla <sudeep.holla@arm.com>
	7	*/
	8
	9	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	10
8410e7f3	11	#include <linux/clk-provider.h>
99d6bdf3 SH	12	#include <linux/cpu.h>
	13	#include <linux/cpufreq.h>
	14	#include <linux/cpumask.h>
3c429851	15	#include <linux/energy_model.h>
99d6bdf3 SH	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>
ae6ccaa6	22	#include <linux/units.h>
99d6bdf3 SH	23
	24	struct scmi_data {
	25	int domain_id;
37f18831	26	int nr_opp;
99d6bdf3	27	struct device *cpu_dev;
37f18831	28	cpumask_var_t opp_shared_cpus;
99d6bdf3 SH	29	};
99d6bdf3 SH	30
eb1d35c6 CM	31	static struct scmi_protocol_handle *ph;
eb1d35c6 CM	32	static const struct scmi_perf_proto_ops *perf_ops;
99d6bdf3 SH	33
	34	static unsigned int scmi_cpufreq_get_rate(unsigned int cpu)
	35	{
	36	struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
99d6bdf3 SH	37	struct scmi_data *priv = policy->driver_data;
	38	unsigned long rate;
	39	int ret;
	40
eb1d35c6	41	ret = perf_ops->freq_get(ph, priv->domain_id, &rate, false);
99d6bdf3 SH	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	*/
	52	static int
	53	scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
	54	{
99d6bdf3	55	struct scmi_data *priv = policy->driver_data;
0e141d1c	56	u64 freq = policy->freq_table[index].frequency;
99d6bdf3	57
eb1d35c6	58	return perf_ops->freq_set(ph, priv->domain_id, freq * 1000, false);
99d6bdf3 SH	59	}
99d6bdf3 SH	60
02f208c5 SH	61	static unsigned int scmi_cpufreq_fast_switch(struct cpufreq_policy *policy,
	62	unsigned int target_freq)
	63	{
	64	struct scmi_data *priv = policy->driver_data;
02f208c5	65
eb1d35c6	66	if (!perf_ops->freq_set(ph, priv->domain_id,
1a0419b0	67	target_freq * 1000, true))
02f208c5	68	return target_freq;
02f208c5 SH	69
	70	return 0;
	71	}
	72
99d6bdf3 SH	73	static int
	74	scmi_get_sharing_cpus(struct device cpu_dev, struct cpumask cpumask)
	75	{
	76	int cpu, domain, tdomain;
	77	struct device *tcpu_dev;
	78
eb1d35c6	79	domain = perf_ops->device_domain_id(cpu_dev);
99d6bdf3 SH	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
eb1d35c6	91	tdomain = perf_ops->device_domain_id(tcpu_dev);
99d6bdf3 SH	92	if (tdomain == domain)
	93	cpumask_set_cpu(cpu, cpumask);
	94	}
	95
	96	return 0;
	97	}
	98
3c429851	99	static int __maybe_unused
75a3a99a LL	100	scmi_get_cpu_power(struct device cpu_dev, unsigned long power,
75a3a99a LL	101	unsigned long *KHz)
3c429851	102	{
f3ac888f	103	enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
3c429851 QP	104	unsigned long Hz;
	105	int ret, domain;
	106
eb1d35c6	107	domain = perf_ops->device_domain_id(cpu_dev);
3c429851 QP	108	if (domain < 0)
	109	return domain;
	110
	111	/* Get the power cost of the performance domain. */
	112	Hz = KHz 1000;
eb1d35c6	113	ret = perf_ops->est_power_get(ph, domain, &Hz, power);
3c429851 QP	114	if (ret)
	115	return ret;
	116
f3ac888f LL	117	/* Convert the power to uW if it is mW (ignore bogoW) */
f3ac888f LL	118	if (power_scale == SCMI_POWER_MILLIWATTS)
ae6ccaa6 LL	119	power = MICROWATT_PER_MILLIWATT;
ae6ccaa6 LL	120
3c429851 QP	121	/* The EM framework specifies the frequency in KHz. */
	122	*KHz = Hz / 1000;
	123
	124	return 0;
	125	}
	126
99d6bdf3 SH	127	static int scmi_cpufreq_init(struct cpufreq_policy *policy)
99d6bdf3 SH	128	{
3c429851	129	int ret, nr_opp;
99d6bdf3 SH	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
37f18831 VK	141	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
37f18831 VK	142	if (!priv)
f7d63588	143	return -ENOMEM;
99d6bdf3	144
37f18831 VK	145	if (!zalloc_cpumask_var(&priv->opp_shared_cpus, GFP_KERNEL)) {
	146	ret = -ENOMEM;
	147	goto out_free_priv;
	148	}
	149
80a064db	150	/* Obtain CPUs that share SCMI performance controls */
99d6bdf3 SH	151	ret = scmi_get_sharing_cpus(cpu_dev, policy->cpus);
	152	if (ret) {
	153	dev_warn(cpu_dev, "failed to get sharing cpumask\n");
80a064db	154	goto out_free_cpumask;
99d6bdf3 SH	155	}
99d6bdf3 SH	156
80a064db NM	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	*/
37f18831	162	ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, priv->opp_shared_cpus);
b48cd0d1	163	if (ret \|\| cpumask_empty(priv->opp_shared_cpus)) {
80a064db NM	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	*/
37f18831	169	cpumask_copy(priv->opp_shared_cpus, policy->cpus);
99d6bdf3 SH	170	}
99d6bdf3 SH	171
80a064db NM	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	*/
3c429851 QP	177	nr_opp = dev_pm_opp_get_opp_count(cpu_dev);
3c429851 QP	178	if (nr_opp <= 0) {
eb1d35c6	179	ret = perf_ops->device_opps_add(ph, cpu_dev);
80a064db NM	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",
b791c7f9	188	__func__, nr_opp);
80a064db NM	189
	190	ret = -ENODEV;
	191	goto out_free_opp;
	192	}
	193
37f18831	194	ret = dev_pm_opp_set_sharing_cpus(cpu_dev, priv->opp_shared_cpus);
80a064db NM	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
37f18831	202	priv->nr_opp = nr_opp;
99d6bdf3 SH	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);
37f18831	208	goto out_free_opp;
99d6bdf3 SH	209	}
	210
	211	priv->cpu_dev = cpu_dev;
eb1d35c6	212	priv->domain_id = perf_ops->device_domain_id(cpu_dev);
99d6bdf3 SH	213
99d6bdf3 SH	214	policy->driver_data = priv;
d983af98	215	policy->freq_table = freq_table;
99d6bdf3 SH	216
	217	/* SCMI allows DVFS request for any domain from any CPU */
	218	policy->dvfs_possible_from_any_cpu = true;
	219
eb1d35c6	220	latency = perf_ops->transition_latency_get(ph, cpu_dev);
99d6bdf3 SH	221	if (!latency)
	222	latency = CPUFREQ_ETERNAL;
	223
	224	policy->cpuinfo.transition_latency = latency;
	225
fb357127	226	policy->fast_switch_possible =
eb1d35c6	227	perf_ops->fast_switch_possible(ph, cpu_dev);
3c429851	228
99d6bdf3 SH	229	return 0;
99d6bdf3 SH	230
99d6bdf3	231	out_free_opp:
1690d8bb	232	dev_pm_opp_remove_all_dynamic(cpu_dev);
99d6bdf3	233
80a064db	234	out_free_cpumask:
37f18831 VK	235	free_cpumask_var(priv->opp_shared_cpus);
	236
	237	out_free_priv:
	238	kfree(priv);
80a064db	239
99d6bdf3 SH	240	return ret;
	241	}
	242
	243	static int scmi_cpufreq_exit(struct cpufreq_policy *policy)
	244	{
	245	struct scmi_data *priv = policy->driver_data;
	246
99d6bdf3	247	dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
1690d8bb	248	dev_pm_opp_remove_all_dynamic(priv->cpu_dev);
37f18831	249	free_cpumask_var(priv->opp_shared_cpus);
8cbd468b	250	kfree(priv);
99d6bdf3 SH	251
	252	return 0;
	253	}
	254
37f18831 VK	255	static void scmi_cpufreq_register_em(struct cpufreq_policy *policy)
	256	{
	257	struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power);
f3ac888f	258	enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph);
37f18831	259	struct scmi_data *priv = policy->driver_data;
f3ac888f	260	bool em_power_scale = false;
37f18831 VK	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
f3ac888f LL	272	if (power_scale == SCMI_POWER_MILLIWATTS
	273	\|\| power_scale == SCMI_POWER_MICROWATTS)
	274	em_power_scale = true;
	275
37f18831 VK	276	em_dev_register_perf_domain(get_cpu_device(policy->cpu), priv->nr_opp,
37f18831 VK	277	&em_cb, priv->opp_shared_cpus,
f3ac888f	278	em_power_scale);
37f18831 VK	279	}
37f18831 VK	280
99d6bdf3 SH	281	static struct cpufreq_driver scmi_cpufreq_driver = {
99d6bdf3 SH	282	.name = "scmi",
5ae4a4b4	283	.flags = CPUFREQ_HAVE_GOVERNOR_PER_POLICY \|
5da7af9a AK	284	CPUFREQ_NEED_INITIAL_FREQ_CHECK \|
5da7af9a AK	285	CPUFREQ_IS_COOLING_DEV,
99d6bdf3 SH	286	.verify = cpufreq_generic_frequency_table_verify,
	287	.attr = cpufreq_generic_attr,
	288	.target_index = scmi_cpufreq_set_target,
02f208c5	289	.fast_switch = scmi_cpufreq_fast_switch,
99d6bdf3 SH	290	.get = scmi_cpufreq_get_rate,
	291	.init = scmi_cpufreq_init,
	292	.exit = scmi_cpufreq_exit,
37f18831	293	.register_em = scmi_cpufreq_register_em,
99d6bdf3 SH	294	};
	295
	296	static int scmi_cpufreq_probe(struct scmi_device *sdev)
	297	{
	298	int ret;
8410e7f3	299	struct device *dev = &sdev->dev;
eb1d35c6	300	const struct scmi_handle *handle;
99d6bdf3 SH	301
	302	handle = sdev->handle;
	303
eb1d35c6	304	if (!handle)
99d6bdf3 SH	305	return -ENODEV;
99d6bdf3 SH	306
eb1d35c6 CM	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
f943849f	311	#ifdef CONFIG_COMMON_CLK
8410e7f3	312	/* dummy clock provider as needed by OPP if clocks property is used */
b8f3a396	313	if (of_property_present(dev->of_node, "#clock-cells"))
8410e7f3	314	devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, NULL);
f943849f	315	#endif
8410e7f3	316
99d6bdf3 SH	317	ret = cpufreq_register_driver(&scmi_cpufreq_driver);
99d6bdf3 SH	318	if (ret) {
f943849f	319	dev_err(dev, "%s: registering cpufreq failed, err: %d\n",
99d6bdf3 SH	320	__func__, ret);
	321	}
	322
	323	return ret;
	324	}
	325
	326	static void scmi_cpufreq_remove(struct scmi_device *sdev)
	327	{
	328	cpufreq_unregister_driver(&scmi_cpufreq_driver);
	329	}
	330
	331	static const struct scmi_device_id scmi_id_table[] = {
12b76626	332	{ SCMI_PROTOCOL_PERF, "cpufreq" },
99d6bdf3 SH	333	{ },
	334	};
	335	MODULE_DEVICE_TABLE(scmi, scmi_id_table);
	336
	337	static 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	};
	343	module_scmi_driver(scmi_cpufreq_drv);
	344
	345	MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
	346	MODULE_DESCRIPTION("ARM SCMI CPUFreq interface driver");
	347	MODULE_LICENSE("GPL v2");