[mirror_ubuntu-bionic-kernel.git] / drivers / cpufreq / ppc-corenet-cpufreq.c

/*
 * Copyright 2013 Freescale Semiconductor, Inc.
 *
 * CPU Frequency Scaling driver for Freescale PowerPC corenet SoCs.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

#include <linux/clk.h>
#include <linux/cpufreq.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <sysdev/fsl_soc.h>

#include <asm/smp.h>	/* for get_hard_smp_processor_id() in UP configs */

/**
 * struct cpu_data - per CPU data struct
 * @parent: the parent node of cpu clock
 * @table: frequency table
 */
struct cpu_data {
	struct device_node *parent;
	struct cpufreq_frequency_table *table;
};

/**
 * struct soc_data - SoC specific data
 * @freq_mask: mask the disallowed frequencies
 * @flag: unique flags
 */
struct soc_data {
	u32 freq_mask[4];
	u32 flag;
};

#define FREQ_MASK	1
/* see hardware specification for the allowed frqeuencies */
static const struct soc_data sdata[] = {
	{ /* used by p2041 and p3041 */
		.freq_mask = {0x8, 0x8, 0x2, 0x2},
		.flag = FREQ_MASK,
	},
	{ /* used by p5020 */
		.freq_mask = {0x8, 0x2},
		.flag = FREQ_MASK,
	},
	{ /* used by p4080, p5040 */
		.freq_mask = {0},
		.flag = 0,
	},
};

/*
 * the minimum allowed core frequency, in Hz
 * for chassis v1.0, >= platform frequency
 * for chassis v2.0, >= platform frequency / 2
 */
static u32 min_cpufreq;
static const u32 *fmask;

static DEFINE_PER_CPU(struct cpu_data *, cpu_data);

/* cpumask in a cluster */
static DEFINE_PER_CPU(cpumask_var_t, cpu_mask);

#ifndef CONFIG_SMP
static inline const struct cpumask *cpu_core_mask(int cpu)
{
	return cpumask_of(0);
}
#endif

/* reduce the duplicated frequencies in frequency table */
static void freq_table_redup(struct cpufreq_frequency_table *freq_table,
		int count)
{
	int i, j;

	for (i = 1; i < count; i++) {
		for (j = 0; j < i; j++) {
			if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID ||
					freq_table[j].frequency !=
					freq_table[i].frequency)
				continue;

			freq_table[i].frequency = CPUFREQ_ENTRY_INVALID;
			break;
		}
	}
}

/* sort the frequencies in frequency table in descenting order */
static void freq_table_sort(struct cpufreq_frequency_table *freq_table,
		int count)
{
	int i, j, ind;
	unsigned int freq, max_freq;
	struct cpufreq_frequency_table table;
	for (i = 0; i < count - 1; i++) {
		max_freq = freq_table[i].frequency;
		ind = i;
		for (j = i + 1; j < count; j++) {
			freq = freq_table[j].frequency;
			if (freq == CPUFREQ_ENTRY_INVALID ||
					freq <= max_freq)
				continue;
			ind = j;
			max_freq = freq;
		}

		if (ind != i) {
			/* exchange the frequencies */
			table.driver_data = freq_table[i].driver_data;
			table.frequency = freq_table[i].frequency;
			freq_table[i].driver_data = freq_table[ind].driver_data;
			freq_table[i].frequency = freq_table[ind].frequency;
			freq_table[ind].driver_data = table.driver_data;
			freq_table[ind].frequency = table.frequency;
		}
	}
}

static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
	struct device_node *np;
	int i, count, ret;
	u32 freq, mask;
	struct clk *clk;
	struct cpufreq_frequency_table *table;
	struct cpu_data *data;
	unsigned int cpu = policy->cpu;
	u64 u64temp;

	np = of_get_cpu_node(cpu, NULL);
	if (!np)
		return -ENODEV;

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data) {
		pr_err("%s: no memory\n", __func__);
		goto err_np;
	}

	policy->clk = of_clk_get(np, 0);
	if (IS_ERR(policy->clk)) {
		pr_err("%s: no clock information\n", __func__);
		goto err_nomem2;
	}

	data->parent = of_parse_phandle(np, "clocks", 0);
	if (!data->parent) {
		pr_err("%s: could not get clock information\n", __func__);
		goto err_nomem2;
	}

	count = of_property_count_strings(data->parent, "clock-names");
	table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
	if (!table) {
		pr_err("%s: no memory\n", __func__);
		goto err_node;
	}

	if (fmask)
		mask = fmask[get_hard_smp_processor_id(cpu)];
	else
		mask = 0x0;

	for (i = 0; i < count; i++) {
		clk = of_clk_get(data->parent, i);
		freq = clk_get_rate(clk);
		/*
		 * the clock is valid if its frequency is not masked
		 * and large than minimum allowed frequency.
		 */
		if (freq < min_cpufreq || (mask & (1 << i)))
			table[i].frequency = CPUFREQ_ENTRY_INVALID;
		else
			table[i].frequency = freq / 1000;
		table[i].driver_data = i;
	}
	freq_table_redup(table, count);
	freq_table_sort(table, count);
	table[i].frequency = CPUFREQ_TABLE_END;

	/* set the min and max frequency properly */
	ret = cpufreq_table_validate_and_show(policy, table);
	if (ret) {
		pr_err("invalid frequency table: %d\n", ret);
		goto err_nomem1;
	}

	data->table = table;

	/* update ->cpus if we have cluster, no harm if not */
	cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
	for_each_cpu(i, per_cpu(cpu_mask, cpu))
		per_cpu(cpu_data, i) = data;

	/* Minimum transition latency is 12 platform clocks */
	u64temp = 12ULL * NSEC_PER_SEC;
	do_div(u64temp, fsl_get_sys_freq());
	policy->cpuinfo.transition_latency = u64temp + 1;

	of_node_put(np);

	return 0;

err_nomem1:
	kfree(table);
err_node:
	of_node_put(data->parent);
err_nomem2:
	per_cpu(cpu_data, cpu) = NULL;
	kfree(data);
err_np:
	of_node_put(np);

	return -ENODEV;
}

static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
	struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
	unsigned int cpu;

	of_node_put(data->parent);
	kfree(data->table);
	kfree(data);

	for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu))
		per_cpu(cpu_data, cpu) = NULL;

	return 0;
}

static int corenet_cpufreq_target(struct cpufreq_policy *policy,
		unsigned int index)
{
	struct clk *parent;
	struct cpu_data *data = per_cpu(cpu_data, policy->cpu);

	parent = of_clk_get(data->parent, data->table[index].driver_data);
	return clk_set_parent(policy->clk, parent);
}

static struct cpufreq_driver ppc_corenet_cpufreq_driver = {
	.name		= "ppc_cpufreq",
	.flags		= CPUFREQ_CONST_LOOPS,
	.init		= corenet_cpufreq_cpu_init,
	.exit		= __exit_p(corenet_cpufreq_cpu_exit),
	.verify		= cpufreq_generic_frequency_table_verify,
	.target_index	= corenet_cpufreq_target,
	.get		= cpufreq_generic_get,
	.attr		= cpufreq_generic_attr,
};

static const struct of_device_id node_matches[] __initdata = {
	{ .compatible = "fsl,p2041-clockgen", .data = &sdata[0], },
	{ .compatible = "fsl,p3041-clockgen", .data = &sdata[0], },
	{ .compatible = "fsl,p5020-clockgen", .data = &sdata[1], },
	{ .compatible = "fsl,p4080-clockgen", .data = &sdata[2], },
	{ .compatible = "fsl,p5040-clockgen", .data = &sdata[2], },
	{ .compatible = "fsl,qoriq-clockgen-2.0", },
	{}
};

static int __init ppc_corenet_cpufreq_init(void)
{
	int ret;
	struct device_node  *np;
	const struct of_device_id *match;
	const struct soc_data *data;
	unsigned int cpu;

	np = of_find_matching_node(NULL, node_matches);
	if (!np)
		return -ENODEV;

	for_each_possible_cpu(cpu) {
		if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL))
			goto err_mask;
		cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu));
	}

	match = of_match_node(node_matches, np);
	data = match->data;
	if (data) {
		if (data->flag)
			fmask = data->freq_mask;
		min_cpufreq = fsl_get_sys_freq();
	} else {
		min_cpufreq = fsl_get_sys_freq() / 2;
	}

	of_node_put(np);

	ret = cpufreq_register_driver(&ppc_corenet_cpufreq_driver);
	if (!ret)
		pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n");

	return ret;

err_mask:
	for_each_possible_cpu(cpu)
		free_cpumask_var(per_cpu(cpu_mask, cpu));

	return -ENOMEM;
}
module_init(ppc_corenet_cpufreq_init);

static void __exit ppc_corenet_cpufreq_exit(void)
{
	unsigned int cpu;

	for_each_possible_cpu(cpu)
		free_cpumask_var(per_cpu(cpu_mask, cpu));

	cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver);
}
module_exit(ppc_corenet_cpufreq_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SoCs");
Commit	Line	Data
defa4c73 TY	1	/*
	2	* Copyright 2013 Freescale Semiconductor, Inc.
	3	*
	4	* CPU Frequency Scaling driver for Freescale PowerPC corenet SoCs.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
	11	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	12
	13	#include <linux/clk.h>
	14	#include <linux/cpufreq.h>
	15	#include <linux/errno.h>
defa4c73 TY	16	#include <linux/init.h>
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/mutex.h>
	20	#include <linux/of.h>
	21	#include <linux/slab.h>
	22	#include <linux/smp.h>
bfa709bc	23	#include <sysdev/fsl_soc.h>
defa4c73	24
5877b4f4 GU	25	#include <asm/smp.h> /* for get_hard_smp_processor_id() in UP configs */
5877b4f4 GU	26
defa4c73 TY	27	/**
defa4c73 TY	28	* struct cpu_data - per CPU data struct
defa4c73 TY	29	* @parent: the parent node of cpu clock
	30	* @table: frequency table
	31	*/
	32	struct cpu_data {
defa4c73 TY	33	struct device_node *parent;
	34	struct cpufreq_frequency_table *table;
	35	};
	36
	37	/**
	38	* struct soc_data - SoC specific data
	39	* @freq_mask: mask the disallowed frequencies
	40	* @flag: unique flags
	41	*/
	42	struct soc_data {
	43	u32 freq_mask[4];
	44	u32 flag;
	45	};
	46
	47	#define FREQ_MASK 1
	48	/* see hardware specification for the allowed frqeuencies */
	49	static const struct soc_data sdata[] = {
	50	{ /* used by p2041 and p3041 */
	51	.freq_mask = {0x8, 0x8, 0x2, 0x2},
	52	.flag = FREQ_MASK,
	53	},
	54	{ /* used by p5020 */
	55	.freq_mask = {0x8, 0x2},
	56	.flag = FREQ_MASK,
	57	},
	58	{ /* used by p4080, p5040 */
	59	.freq_mask = {0},
	60	.flag = 0,
	61	},
	62	};
	63
	64	/*
	65	* the minimum allowed core frequency, in Hz
	66	* for chassis v1.0, >= platform frequency
	67	* for chassis v2.0, >= platform frequency / 2
	68	*/
	69	static u32 min_cpufreq;
	70	static const u32 *fmask;
	71
defa4c73 TY	72	static DEFINE_PER_CPU(struct cpu_data *, cpu_data);
	73
	74	/* cpumask in a cluster */
	75	static DEFINE_PER_CPU(cpumask_var_t, cpu_mask);
	76
	77	#ifndef CONFIG_SMP
	78	static inline const struct cpumask *cpu_core_mask(int cpu)
	79	{
	80	return cpumask_of(0);
	81	}
	82	#endif
	83
defa4c73 TY	84	/* reduce the duplicated frequencies in frequency table */
	85	static void freq_table_redup(struct cpufreq_frequency_table *freq_table,
	86	int count)
	87	{
	88	int i, j;
	89
	90	for (i = 1; i < count; i++) {
	91	for (j = 0; j < i; j++) {
	92	if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID \|\|
	93	freq_table[j].frequency !=
	94	freq_table[i].frequency)
	95	continue;
	96
	97	freq_table[i].frequency = CPUFREQ_ENTRY_INVALID;
	98	break;
	99	}
	100	}
	101	}
	102
	103	/* sort the frequencies in frequency table in descenting order */
	104	static void freq_table_sort(struct cpufreq_frequency_table *freq_table,
	105	int count)
	106	{
	107	int i, j, ind;
	108	unsigned int freq, max_freq;
	109	struct cpufreq_frequency_table table;
	110	for (i = 0; i < count - 1; i++) {
	111	max_freq = freq_table[i].frequency;
	112	ind = i;
	113	for (j = i + 1; j < count; j++) {
	114	freq = freq_table[j].frequency;
	115	if (freq == CPUFREQ_ENTRY_INVALID \|\|
	116	freq <= max_freq)
	117	continue;
	118	ind = j;
	119	max_freq = freq;
	120	}
	121
	122	if (ind != i) {
	123	/* exchange the frequencies */
	124	table.driver_data = freq_table[i].driver_data;
	125	table.frequency = freq_table[i].frequency;
	126	freq_table[i].driver_data = freq_table[ind].driver_data;
	127	freq_table[i].frequency = freq_table[ind].frequency;
	128	freq_table[ind].driver_data = table.driver_data;
	129	freq_table[ind].frequency = table.frequency;
	130	}
	131	}
	132	}
	133
	134	static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
	135	{
	136	struct device_node *np;
	137	int i, count, ret;
	138	u32 freq, mask;
	139	struct clk *clk;
	140	struct cpufreq_frequency_table *table;
	141	struct cpu_data *data;
	142	unsigned int cpu = policy->cpu;
906fe033	143	u64 u64temp;
defa4c73 TY	144
	145	np = of_get_cpu_node(cpu, NULL);
	146	if (!np)
	147	return -ENODEV;
	148
	149	data = kzalloc(sizeof(*data), GFP_KERNEL);
	150	if (!data) {
	151	pr_err("%s: no memory\n", __func__);
	152	goto err_np;
	153	}
	154
652ed95d VK	155	policy->clk = of_clk_get(np, 0);
652ed95d VK	156	if (IS_ERR(policy->clk)) {
defa4c73 TY	157	pr_err("%s: no clock information\n", __func__);
	158	goto err_nomem2;
	159	}
	160
	161	data->parent = of_parse_phandle(np, "clocks", 0);
	162	if (!data->parent) {
	163	pr_err("%s: could not get clock information\n", __func__);
	164	goto err_nomem2;
	165	}
	166
	167	count = of_property_count_strings(data->parent, "clock-names");
	168	table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
	169	if (!table) {
	170	pr_err("%s: no memory\n", __func__);
	171	goto err_node;
	172	}
	173
	174	if (fmask)
	175	mask = fmask[get_hard_smp_processor_id(cpu)];
	176	else
	177	mask = 0x0;
	178
	179	for (i = 0; i < count; i++) {
	180	clk = of_clk_get(data->parent, i);
	181	freq = clk_get_rate(clk);
	182	/*
	183	* the clock is valid if its frequency is not masked
	184	* and large than minimum allowed frequency.
	185	*/
	186	if (freq < min_cpufreq \|\| (mask & (1 << i)))
	187	table[i].frequency = CPUFREQ_ENTRY_INVALID;
	188	else
	189	table[i].frequency = freq / 1000;
	190	table[i].driver_data = i;
	191	}
	192	freq_table_redup(table, count);
	193	freq_table_sort(table, count);
	194	table[i].frequency = CPUFREQ_TABLE_END;
	195
	196	/* set the min and max frequency properly */
6b4147db	197	ret = cpufreq_table_validate_and_show(policy, table);
defa4c73 TY	198	if (ret) {
	199	pr_err("invalid frequency table: %d\n", ret);
	200	goto err_nomem1;
	201	}
	202
	203	data->table = table;
defa4c73 TY	204
	205	/* update ->cpus if we have cluster, no harm if not */
	206	cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
	207	for_each_cpu(i, per_cpu(cpu_mask, cpu))
	208	per_cpu(cpu_data, i) = data;
	209
906fe033 ES	210	/* Minimum transition latency is 12 platform clocks */
	211	u64temp = 12ULL * NSEC_PER_SEC;
	212	do_div(u64temp, fsl_get_sys_freq());
	213	policy->cpuinfo.transition_latency = u64temp + 1;
6712d293	214
defa4c73 TY	215	of_node_put(np);
	216
	217	return 0;
	218
	219	err_nomem1:
	220	kfree(table);
	221	err_node:
	222	of_node_put(data->parent);
	223	err_nomem2:
	224	per_cpu(cpu_data, cpu) = NULL;
	225	kfree(data);
	226	err_np:
	227	of_node_put(np);
	228
	229	return -ENODEV;
	230	}
	231
	232	static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	233	{
	234	struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
	235	unsigned int cpu;
	236
defa4c73 TY	237	of_node_put(data->parent);
	238	kfree(data->table);
	239	kfree(data);
	240
	241	for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu))
	242	per_cpu(cpu_data, cpu) = NULL;
	243
	244	return 0;
	245	}
	246
defa4c73	247	static int corenet_cpufreq_target(struct cpufreq_policy *policy,
9c0ebcf7	248	unsigned int index)
defa4c73	249	{
defa4c73	250	struct clk *parent;
defa4c73 TY	251	struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
defa4c73 TY	252
9c0ebcf7	253	parent = of_clk_get(data->parent, data->table[index].driver_data);
652ed95d	254	return clk_set_parent(policy->clk, parent);
defa4c73 TY	255	}
defa4c73 TY	256
defa4c73 TY	257	static struct cpufreq_driver ppc_corenet_cpufreq_driver = {
defa4c73 TY	258	.name = "ppc_cpufreq",
defa4c73 TY	259	.flags = CPUFREQ_CONST_LOOPS,
	260	.init = corenet_cpufreq_cpu_init,
	261	.exit = __exit_p(corenet_cpufreq_cpu_exit),
dc2398d7	262	.verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7	263	.target_index = corenet_cpufreq_target,
652ed95d	264	.get = cpufreq_generic_get,
dc2398d7	265	.attr = cpufreq_generic_attr,
defa4c73 TY	266	};
	267
	268	static const struct of_device_id node_matches[] __initdata = {
	269	{ .compatible = "fsl,p2041-clockgen", .data = &sdata[0], },
	270	{ .compatible = "fsl,p3041-clockgen", .data = &sdata[0], },
	271	{ .compatible = "fsl,p5020-clockgen", .data = &sdata[1], },
	272	{ .compatible = "fsl,p4080-clockgen", .data = &sdata[2], },
	273	{ .compatible = "fsl,p5040-clockgen", .data = &sdata[2], },
	274	{ .compatible = "fsl,qoriq-clockgen-2.0", },
	275	{}
	276	};
	277
	278	static int __init ppc_corenet_cpufreq_init(void)
	279	{
	280	int ret;
	281	struct device_node *np;
	282	const struct of_device_id *match;
	283	const struct soc_data *data;
	284	unsigned int cpu;
	285
	286	np = of_find_matching_node(NULL, node_matches);
	287	if (!np)
	288	return -ENODEV;
	289
	290	for_each_possible_cpu(cpu) {
	291	if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL))
	292	goto err_mask;
	293	cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu));
	294	}
	295
	296	match = of_match_node(node_matches, np);
	297	data = match->data;
	298	if (data) {
	299	if (data->flag)
	300	fmask = data->freq_mask;
	301	min_cpufreq = fsl_get_sys_freq();
	302	} else {
	303	min_cpufreq = fsl_get_sys_freq() / 2;
	304	}
	305
	306	of_node_put(np);
	307
	308	ret = cpufreq_register_driver(&ppc_corenet_cpufreq_driver);
	309	if (!ret)
	310	pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n");
	311
	312	return ret;
	313
	314	err_mask:
	315	for_each_possible_cpu(cpu)
	316	free_cpumask_var(per_cpu(cpu_mask, cpu));
	317
	318	return -ENOMEM;
	319	}
	320	module_init(ppc_corenet_cpufreq_init);
	321
	322	static void __exit ppc_corenet_cpufreq_exit(void)
	323	{
	324	unsigned int cpu;
	325
	326	for_each_possible_cpu(cpu)
	327	free_cpumask_var(per_cpu(cpu_mask, cpu));
	328
	329	cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver);
330	}
331	module_exit(ppc_corenet_cpufreq_exit);
332
333	MODULE_LICENSE("GPL");
334	MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
335	MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SoCs");