[deliverable/linux.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 <sysdev/fsl_soc.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>

/**
 * 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;

	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;
	per_cpu(cpu_data, cpu) = data;

	/* 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;

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