cpufreq: Add snapshot of qcom-cpufreq driver

Qualcomm MSM CPUfreq device

msm-cpufreq is a device that represents the list of usable CPU frequencies

and provides a device handle for the CPUfreq driver to get the CPU and cache

clocks.

Required properties:

- compatible:		Must be "qcom,msm-cpufreq"

- qcom,cpufreq-table, or qcom,cpufreq-table-<X>:

			A list of usable CPU frequencies (KHz).

			Use "qcom,cpufreq-table" if all CPUs in the system

			should share same list of frequencies.

			Use "qcom,cpufreq-table-<cpuid>" to describe

			different CPU freq tables for different CPUs.

			The table should be listed only for the first CPU

			if multiple CPUs are synchronous.

Optional properties:

- clock-names:		When DT based binding of clock is available, this

			provides a list of CPU subsystem clocks.

			"cpuX_clk" for every CPU that's present.

			"l2_clk" when an async cache/CCI is present.

Optional properties:

- qcom,governor-per-policy:	This property denotes that governor tunables

				should be associated with each cpufreq policy

				group instead of being global.

Example:

	qcom,msm-cpufreq {

		compatible = "qcom,msm-cpufreq";

		qcom,cpufreq-table =

			<  300000 >,

			<  422400 >,

			<  652800 >,

			<  729600 >,

			<  883200 >,

			<  960000 >,

			< 1036800 >,

			< 1190400 >,

			< 1267200 >,

			< 1497600 >,

			< 1574400 >,

			< 1728000 >,

			< 1958400 >,

			< 2265600 >;

	};

	  support for its operation.

	  If in doubt, say N.

config CPU_FREQ_MSM

	bool "MSM CPUFreq support"

	depends on CPU_FREQ

	help

	  This enables the CPUFreq driver for Qualcomm Technologies, Inc. CPUs.

obj-$(CONFIG_ARM_IMX6Q_CPUFREQ)		+= imx6q-cpufreq.o

obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ)	+= kirkwood-cpufreq.o

obj-$(CONFIG_ARM_MEDIATEK_CPUFREQ)	+= mediatek-cpufreq.o

obj-$(CONFIG_CPU_FREQ_MSM)              += qcom-cpufreq.o

obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ)	+= omap-cpufreq.o

obj-$(CONFIG_ARM_PXA2xx_CPUFREQ)	+= pxa2xx-cpufreq.o

obj-$(CONFIG_PXA3xx)			+= pxa3xx-cpufreq.o

obj-$(CONFIG_ACPI_CPPC_CPUFREQ) += cppc_cpufreq.o

obj-$(CONFIG_MACH_MVEBU_V7)		+= mvebu-cpufreq.o

##################################################################################

# PowerPC platform drivers

obj-$(CONFIG_CPU_FREQ_CBE)		+= ppc-cbe-cpufreq.o

/* drivers/cpufreq/qcom-cpufreq.c

 *

 * MSM architecture cpufreq driver

 *

 * Copyright (C) 2007 Google, Inc.

 * Copyright (c) 2007-2017, The Linux Foundation. All rights reserved.

 * Author: Mike A. Chan <mikechan@google.com>

 *

 * This software is licensed under the terms of the GNU General Public

 * License version 2, as published by the Free Software Foundation, and

 * may be copied, distributed, and modified under those terms.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the

 * GNU General Public License for more details.

 *

 */

#include <linux/init.h>

#include <linux/module.h>

#include <linux/cpufreq.h>

#include <linux/cpu.h>

#include <linux/cpumask.h>

#include <linux/suspend.h>

#include <linux/clk.h>

#include <linux/err.h>

#include <linux/platform_device.h>

#include <linux/of.h>

#include <trace/events/power.h>

static DEFINE_MUTEX(l2bw_lock);

static struct clk *cpu_clk[NR_CPUS];

static struct clk *l2_clk;

static DEFINE_PER_CPU(struct cpufreq_frequency_table *, freq_table);

static bool hotplug_ready;

struct cpufreq_suspend_t {

	struct mutex suspend_mutex;

	int device_suspended;

};

static DEFINE_PER_CPU(struct cpufreq_suspend_t, suspend_data);

static int set_cpu_freq(struct cpufreq_policy *policy, unsigned int new_freq,

			unsigned int index)

{

	int ret = 0;

	struct cpufreq_freqs freqs;

	unsigned long rate;

	freqs.old = policy->cur;

	freqs.new = new_freq;

	freqs.cpu = policy->cpu;

	trace_cpu_frequency_switch_start(freqs.old, freqs.new, policy->cpu);

	cpufreq_freq_transition_begin(policy, &freqs);

	rate = new_freq * 1000;

	rate = clk_round_rate(cpu_clk[policy->cpu], rate);

	ret = clk_set_rate(cpu_clk[policy->cpu], rate);

	cpufreq_freq_transition_end(policy, &freqs, ret);

	if (!ret)

		trace_cpu_frequency_switch_end(policy->cpu);

	return ret;

}

static int msm_cpufreq_target(struct cpufreq_policy *policy,

				unsigned int target_freq,

				unsigned int relation)

{

	int ret = -EFAULT;

	int index;

	struct cpufreq_frequency_table *table;

	mutex_lock(&per_cpu(suspend_data, policy->cpu).suspend_mutex);

	if (per_cpu(suspend_data, policy->cpu).device_suspended) {

		pr_debug("cpufreq: cpu%d scheduling frequency change in suspend\n",

			 policy->cpu);

		ret = -EFAULT;

		goto done;

	}

	table = policy->freq_table;

	pr_debug("CPU[%d] target %d relation %d (%d-%d) selected %d\n",

		policy->cpu, target_freq, relation,

		policy->min, policy->max, table[index].frequency);

	ret = set_cpu_freq(policy, table[index].frequency,

			   table[index].driver_data);

done:

	mutex_unlock(&per_cpu(suspend_data, policy->cpu).suspend_mutex);

	return ret;

}

static int msm_cpufreq_verify(struct cpufreq_policy *policy)

{

	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,

			policy->cpuinfo.max_freq);

	return 0;

}

static unsigned int msm_cpufreq_get_freq(unsigned int cpu)

{

	return clk_get_rate(cpu_clk[cpu]) / 1000;

}

static int msm_cpufreq_init(struct cpufreq_policy *policy)

{

	int cur_freq;

	int index;

	int ret = 0;

	struct cpufreq_frequency_table *table =

			per_cpu(freq_table, policy->cpu);

	int cpu;

	/*

	 * In some SoC, some cores are clocked by same source, and their

	 * frequencies can not be changed independently. Find all other

	 * CPUs that share same clock, and mark them as controlled by

	 * same policy.

	 */

	for_each_possible_cpu(cpu)

		if (cpu_clk[cpu] == cpu_clk[policy->cpu])

			cpumask_set_cpu(cpu, policy->cpus);

	ret = cpufreq_table_validate_and_show(policy, table);

	if (ret) {

		pr_err("cpufreq: failed to get policy min/max\n");

		return ret;

	}

	cur_freq = clk_get_rate(cpu_clk[policy->cpu])/1000;

	index =  cpufreq_frequency_table_target(policy, cur_freq,

						CPUFREQ_RELATION_H);

	/*

	 * Call set_cpu_freq unconditionally so that when cpu is set to

	 * online, frequency limit will always be updated.

	 */

	ret = set_cpu_freq(policy, table[index].frequency,

			   table[index].driver_data);

	if (ret)

		return ret;

	pr_debug("cpufreq: cpu%d init at %d switching to %d\n",

			policy->cpu, cur_freq, table[index].frequency);

	policy->cur = table[index].frequency;

	return 0;

}

static int qcom_cpufreq_dead_cpu(unsigned int cpu)

{

	/* Fail hotplug until this driver can get CPU clocks */

	if (!hotplug_ready)

		return -EINVAL;

	clk_unprepare(cpu_clk[cpu]);

	clk_unprepare(l2_clk);

	return 0;

}

static int qcom_cpufreq_up_cpu(unsigned int cpu)

{

	int rc;

	/* Fail hotplug until this driver can get CPU clocks */

	if (!hotplug_ready)

		return -EINVAL;

	rc = clk_prepare(l2_clk);

	if (rc < 0)

		return rc;

	rc = clk_prepare(cpu_clk[cpu]);

	if (rc < 0)

		clk_unprepare(l2_clk);

	return rc;

}

static int qcom_cpufreq_dying_cpu(unsigned int cpu)

{

	/* Fail hotplug until this driver can get CPU clocks */

	if (!hotplug_ready)

		return -EINVAL;

	clk_disable(cpu_clk[cpu]);

	clk_disable(l2_clk);

	return 0;

}

static int qcom_cpufreq_starting_cpu(unsigned int cpu)

{

	int rc;

	/* Fail hotplug until this driver can get CPU clocks */

	if (!hotplug_ready)

		return -EINVAL;

	rc = clk_enable(l2_clk);

	if (rc < 0)

		return rc;

	rc = clk_enable(cpu_clk[cpu]);

	if (rc < 0)

		clk_disable(l2_clk);

	return rc;

}

static int msm_cpufreq_suspend(void)

{

	int cpu;

	for_each_possible_cpu(cpu) {

		mutex_lock(&per_cpu(suspend_data, cpu).suspend_mutex);

		per_cpu(suspend_data, cpu).device_suspended = 1;

		mutex_unlock(&per_cpu(suspend_data, cpu).suspend_mutex);

	}

	return NOTIFY_DONE;

}

static int msm_cpufreq_resume(void)

{

	int cpu, ret;

	struct cpufreq_policy policy;

	for_each_possible_cpu(cpu) {

		per_cpu(suspend_data, cpu).device_suspended = 0;

	}

	/*

	 * Freq request might be rejected during suspend, resulting

	 * in policy->cur violating min/max constraint.

	 * Correct the frequency as soon as possible.

	 */

	get_online_cpus();

	for_each_online_cpu(cpu) {

		ret = cpufreq_get_policy(&policy, cpu);

		if (ret)

			continue;

		if (policy.cur <= policy.max && policy.cur >= policy.min)

			continue;

		cpufreq_update_policy(cpu);

	}

	put_online_cpus();

	return NOTIFY_DONE;

}

static int msm_cpufreq_pm_event(struct notifier_block *this,

				unsigned long event, void *ptr)

{

	switch (event) {

	case PM_POST_HIBERNATION:

	case PM_POST_SUSPEND:

		return msm_cpufreq_resume();

	case PM_HIBERNATION_PREPARE:

	case PM_SUSPEND_PREPARE:

		return msm_cpufreq_suspend();

	default:

		return NOTIFY_DONE;

	}

}

static struct notifier_block msm_cpufreq_pm_notifier = {

	.notifier_call = msm_cpufreq_pm_event,

};

static struct freq_attr *msm_freq_attr[] = {

	&cpufreq_freq_attr_scaling_available_freqs,

	NULL,

};

static struct cpufreq_driver msm_cpufreq_driver = {

	/* lps calculations are handled here. */

	.flags		= CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS |

				CPUFREQ_NEED_INITIAL_FREQ_CHECK,

	.init		= msm_cpufreq_init,

	.verify		= msm_cpufreq_verify,

	.target		= msm_cpufreq_target,

	.get		= msm_cpufreq_get_freq,

	.name		= "msm",

	.attr		= msm_freq_attr,

};

static struct cpufreq_frequency_table *cpufreq_parse_dt(struct device *dev,

						char *tbl_name, int cpu)

{

	int ret, nf, i, j;

	u32 *data;

	struct cpufreq_frequency_table *ftbl;

	/* Parse list of usable CPU frequencies. */

	if (!of_find_property(dev->of_node, tbl_name, &nf))

		return ERR_PTR(-EINVAL);

	nf /= sizeof(*data);

	if (nf == 0)

		return ERR_PTR(-EINVAL);

	data = devm_kzalloc(dev, nf * sizeof(*data), GFP_KERNEL);

	if (!data)

		return ERR_PTR(-ENOMEM);

	ret = of_property_read_u32_array(dev->of_node, tbl_name, data, nf);

	if (ret)

		return ERR_PTR(ret);

	ftbl = devm_kzalloc(dev, (nf + 1) * sizeof(*ftbl), GFP_KERNEL);

	if (!ftbl)

		return ERR_PTR(-ENOMEM);

	j = 0;

	for (i = 0; i < nf; i++) {

		unsigned long f;

		f = clk_round_rate(cpu_clk[cpu], data[i] * 1000);

		if (IS_ERR_VALUE(f))

			break;

		f /= 1000;

		/*

		 * Don't repeat frequencies if they round up to the same clock

		 * frequency.

		 *

		 */

		if (j > 0 && f <= ftbl[j - 1].frequency)

			continue;

		ftbl[j].driver_data = j;

		ftbl[j].frequency = f;

		j++;

	}

	ftbl[j].driver_data = j;

	ftbl[j].frequency = CPUFREQ_TABLE_END;

	devm_kfree(dev, data);

	return ftbl;

}

static int msm_cpufreq_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	char clk_name[] = "cpu??_clk";

	char tbl_name[] = "qcom,cpufreq-table-??";

	struct clk *c;

	int cpu;

	struct cpufreq_frequency_table *ftbl;

	l2_clk = devm_clk_get(dev, "l2_clk");

	if (IS_ERR(l2_clk))

		l2_clk = NULL;

	for_each_possible_cpu(cpu) {

		snprintf(clk_name, sizeof(clk_name), "cpu%d_clk", cpu);

		c = devm_clk_get(dev, clk_name);

		if (cpu == 0 && IS_ERR(c))

			return PTR_ERR(c);

		else if (IS_ERR(c))

			c = cpu_clk[cpu-1];

		cpu_clk[cpu] = c;

	}

	hotplug_ready = true;

	/* Use per-policy governor tunable for some targets */

	if (of_property_read_bool(dev->of_node, "qcom,governor-per-policy"))

		msm_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY;

	/* Parse commong cpufreq table for all CPUs */

	ftbl = cpufreq_parse_dt(dev, "qcom,cpufreq-table", 0);

	if (!IS_ERR(ftbl)) {

		for_each_possible_cpu(cpu)

			per_cpu(freq_table, cpu) = ftbl;

		return 0;

	}

	/*

	 * No common table. Parse individual tables for each unique

	 * CPU clock.

	 */

	for_each_possible_cpu(cpu) {

		snprintf(tbl_name, sizeof(tbl_name),

			 "qcom,cpufreq-table-%d", cpu);

		ftbl = cpufreq_parse_dt(dev, tbl_name, cpu);

		/* CPU0 must contain freq table */

		if (cpu == 0 && IS_ERR(ftbl)) {

			dev_err(dev, "Failed to parse CPU0's freq table\n");

			return PTR_ERR(ftbl);

		}

		if (cpu == 0) {

			per_cpu(freq_table, cpu) = ftbl;

			continue;

		}

		if (cpu_clk[cpu] != cpu_clk[cpu - 1] && IS_ERR(ftbl)) {

			dev_err(dev, "Failed to parse CPU%d's freq table\n",

				cpu);

			return PTR_ERR(ftbl);

		}

		/* Use previous CPU's table if it shares same clock */

		if (cpu_clk[cpu] == cpu_clk[cpu - 1]) {

			if (!IS_ERR(ftbl)) {

				dev_warn(dev, "Conflicting tables for CPU%d\n",

					 cpu);

				devm_kfree(dev, ftbl);

			}

			ftbl = per_cpu(freq_table, cpu - 1);

		}

		per_cpu(freq_table, cpu) = ftbl;

	}

	return 0;

}

static const struct of_device_id msm_cpufreq_match_table[] = {

	{ .compatible = "qcom,msm-cpufreq" },

	{}

};

static struct platform_driver msm_cpufreq_plat_driver = {

	.probe = msm_cpufreq_probe,

	.driver = {

		.name = "msm-cpufreq",

		.of_match_table = msm_cpufreq_match_table,

	},

};

static int __init msm_cpufreq_register(void)

{

	int cpu, rc;

	for_each_possible_cpu(cpu) {

		mutex_init(&(per_cpu(suspend_data, cpu).suspend_mutex));

		per_cpu(suspend_data, cpu).device_suspended = 0;

	}

	rc = platform_driver_register(&msm_cpufreq_plat_driver);

	if (rc < 0) {

		/* Unblock hotplug if msm-cpufreq probe fails */

		cpuhp_remove_state_nocalls(CPUHP_QCOM_CPUFREQ_PREPARE);

		cpuhp_remove_state_nocalls(CPUHP_AP_QCOM_CPUFREQ_STARTING);

		for_each_possible_cpu(cpu)

			mutex_destroy(&(per_cpu(suspend_data, cpu).

					suspend_mutex));

		return rc;

	}

	register_pm_notifier(&msm_cpufreq_pm_notifier);

	return cpufreq_register_driver(&msm_cpufreq_driver);

}

subsys_initcall(msm_cpufreq_register);

static int __init msm_cpufreq_early_register(void)

{

	int ret;

	ret = cpuhp_setup_state_nocalls(CPUHP_AP_QCOM_CPUFREQ_STARTING,

					"AP_QCOM_CPUFREQ_STARTING",

					qcom_cpufreq_starting_cpu,

					qcom_cpufreq_dying_cpu);

	if (ret)

		return ret;

	ret = cpuhp_setup_state_nocalls(CPUHP_QCOM_CPUFREQ_PREPARE,

					"QCOM_CPUFREQ_PREPARE",

					qcom_cpufreq_up_cpu,

					qcom_cpufreq_dead_cpu);

	if (!ret)

		return ret;

	cpuhp_remove_state_nocalls(CPUHP_AP_QCOM_CPUFREQ_STARTING);

	return ret;

}

core_initcall(msm_cpufreq_early_register);

	CPUHP_POWERPC_MMU_CTX_PREPARE,

	CPUHP_XEN_PREPARE,

	CPUHP_XEN_EVTCHN_PREPARE,

	CPUHP_QCOM_CPUFREQ_PREPARE,

	CPUHP_ARM_SHMOBILE_SCU_PREPARE,

	CPUHP_SH_SH3X_PREPARE,

	CPUHP_NET_FLOW_PREPARE,

	CPUHP_AP_ARM_TWD_STARTING,

	CPUHP_AP_METAG_TIMER_STARTING,

	CPUHP_AP_QCOM_TIMER_STARTING,

	CPUHP_AP_QCOM_CPUFREQ_STARTING,

	CPUHP_AP_ARMADA_TIMER_STARTING,

	CPUHP_AP_MARCO_TIMER_STARTING,

	CPUHP_AP_MIPS_GIC_TIMER_STARTING,