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