[mirror_ubuntu-artful-kernel.git] / drivers / cpufreq / exynos5440-cpufreq.c

/*
 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * Amit Daniel Kachhap <amit.daniel@samsung.com>
 *
 * EXYNOS5440 - CPU frequency scaling support
 *
 * 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.
*/

#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/opp.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

/* Register definitions */
#define XMU_DVFS_CTRL		0x0060
#define XMU_PMU_P0_7		0x0064
#define XMU_C0_3_PSTATE		0x0090
#define XMU_P_LIMIT		0x00a0
#define XMU_P_STATUS		0x00a4
#define XMU_PMUEVTEN		0x00d0
#define XMU_PMUIRQEN		0x00d4
#define XMU_PMUIRQ		0x00d8

/* PMU mask and shift definations */
#define P_VALUE_MASK		0x7

#define XMU_DVFS_CTRL_EN_SHIFT	0

#define P0_7_CPUCLKDEV_SHIFT	21
#define P0_7_CPUCLKDEV_MASK	0x7
#define P0_7_ATBCLKDEV_SHIFT	18
#define P0_7_ATBCLKDEV_MASK	0x7
#define P0_7_CSCLKDEV_SHIFT	15
#define P0_7_CSCLKDEV_MASK	0x7
#define P0_7_CPUEMA_SHIFT	28
#define P0_7_CPUEMA_MASK	0xf
#define P0_7_L2EMA_SHIFT	24
#define P0_7_L2EMA_MASK		0xf
#define P0_7_VDD_SHIFT		8
#define P0_7_VDD_MASK		0x7f
#define P0_7_FREQ_SHIFT		0
#define P0_7_FREQ_MASK		0xff

#define C0_3_PSTATE_VALID_SHIFT	8
#define C0_3_PSTATE_CURR_SHIFT	4
#define C0_3_PSTATE_NEW_SHIFT	0

#define PSTATE_CHANGED_EVTEN_SHIFT	0

#define PSTATE_CHANGED_IRQEN_SHIFT	0

#define PSTATE_CHANGED_SHIFT		0

/* some constant values for clock divider calculation */
#define CPU_DIV_FREQ_MAX	500
#define CPU_DBG_FREQ_MAX	375
#define CPU_ATB_FREQ_MAX	500

#define PMIC_LOW_VOLT		0x30
#define PMIC_HIGH_VOLT		0x28

#define CPUEMA_HIGH		0x2
#define CPUEMA_MID		0x4
#define CPUEMA_LOW		0x7

#define L2EMA_HIGH		0x1
#define L2EMA_MID		0x3
#define L2EMA_LOW		0x4

#define DIV_TAB_MAX	2
/* frequency unit is 20MHZ */
#define FREQ_UNIT	20
#define MAX_VOLTAGE	1550000 /* In microvolt */
#define VOLTAGE_STEP	12500	/* In microvolt */

#define CPUFREQ_NAME		"exynos5440_dvfs"
#define DEF_TRANS_LATENCY	100000

enum cpufreq_level_index {
	L0, L1, L2, L3, L4,
	L5, L6, L7, L8, L9,
};
#define CPUFREQ_LEVEL_END	(L7 + 1)

struct exynos_dvfs_data {
	void __iomem *base;
	struct resource *mem;
	int irq;
	struct clk *cpu_clk;
	unsigned int cur_frequency;
	unsigned int latency;
	struct cpufreq_frequency_table *freq_table;
	unsigned int freq_count;
	struct device *dev;
	bool dvfs_enabled;
	struct work_struct irq_work;
};

static struct exynos_dvfs_data *dvfs_info;
static DEFINE_MUTEX(cpufreq_lock);
static struct cpufreq_freqs freqs;

static int init_div_table(void)
{
	struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
	unsigned int tmp, clk_div, ema_div, freq, volt_id;
	int i = 0;
	struct opp *opp;

	for (i = 0; freq_tbl[i].frequency != CPUFREQ_TABLE_END; i++) {

		opp = opp_find_freq_exact(dvfs_info->dev,
					freq_tbl[i].frequency * 1000, true);
		if (IS_ERR(opp)) {
			dev_err(dvfs_info->dev,
				"failed to find valid OPP for %u KHZ\n",
				freq_tbl[i].frequency);
			return PTR_ERR(opp);
		}

		freq = freq_tbl[i].frequency / 1000; /* In MHZ */
		clk_div = ((freq / CPU_DIV_FREQ_MAX) & P0_7_CPUCLKDEV_MASK)
					<< P0_7_CPUCLKDEV_SHIFT;
		clk_div |= ((freq / CPU_ATB_FREQ_MAX) & P0_7_ATBCLKDEV_MASK)
					<< P0_7_ATBCLKDEV_SHIFT;
		clk_div |= ((freq / CPU_DBG_FREQ_MAX) & P0_7_CSCLKDEV_MASK)
					<< P0_7_CSCLKDEV_SHIFT;

		/* Calculate EMA */
		volt_id = opp_get_voltage(opp);
		volt_id = (MAX_VOLTAGE - volt_id) / VOLTAGE_STEP;
		if (volt_id < PMIC_HIGH_VOLT) {
			ema_div = (CPUEMA_HIGH << P0_7_CPUEMA_SHIFT) |
				(L2EMA_HIGH << P0_7_L2EMA_SHIFT);
		} else if (volt_id > PMIC_LOW_VOLT) {
			ema_div = (CPUEMA_LOW << P0_7_CPUEMA_SHIFT) |
				(L2EMA_LOW << P0_7_L2EMA_SHIFT);
		} else {
			ema_div = (CPUEMA_MID << P0_7_CPUEMA_SHIFT) |
				(L2EMA_MID << P0_7_L2EMA_SHIFT);
		}

		tmp = (clk_div | ema_div | (volt_id << P0_7_VDD_SHIFT)
			| ((freq / FREQ_UNIT) << P0_7_FREQ_SHIFT));

		__raw_writel(tmp, dvfs_info->base + XMU_PMU_P0_7 + 4 * i);
	}

	return 0;
}

static void exynos_enable_dvfs(void)
{
	unsigned int tmp, i, cpu;
	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
	/* Disable DVFS */
	__raw_writel(0,	dvfs_info->base + XMU_DVFS_CTRL);

	/* Enable PSTATE Change Event */
	tmp = __raw_readl(dvfs_info->base + XMU_PMUEVTEN);
	tmp |= (1 << PSTATE_CHANGED_EVTEN_SHIFT);
	 __raw_writel(tmp, dvfs_info->base + XMU_PMUEVTEN);

	/* Enable PSTATE Change IRQ */
	tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQEN);
	tmp |= (1 << PSTATE_CHANGED_IRQEN_SHIFT);
	 __raw_writel(tmp, dvfs_info->base + XMU_PMUIRQEN);

	/* Set initial performance index */
	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
		if (freq_table[i].frequency == dvfs_info->cur_frequency)
			break;

	if (freq_table[i].frequency == CPUFREQ_TABLE_END) {
		dev_crit(dvfs_info->dev, "Boot up frequency not supported\n");
		/* Assign the highest frequency */
		i = 0;
		dvfs_info->cur_frequency = freq_table[i].frequency;
	}

	dev_info(dvfs_info->dev, "Setting dvfs initial frequency = %uKHZ",
						dvfs_info->cur_frequency);

	for (cpu = 0; cpu < CONFIG_NR_CPUS; cpu++) {
		tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4);
		tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT);
		tmp |= (i << C0_3_PSTATE_NEW_SHIFT);
		__raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4);
	}

	/* Enable DVFS */
	__raw_writel(1 << XMU_DVFS_CTRL_EN_SHIFT,
				dvfs_info->base + XMU_DVFS_CTRL);
}

static int exynos_verify_speed(struct cpufreq_policy *policy)
{
	return cpufreq_frequency_table_verify(policy,
					      dvfs_info->freq_table);
}

static unsigned int exynos_getspeed(unsigned int cpu)
{
	return dvfs_info->cur_frequency;
}

static int exynos_target(struct cpufreq_policy *policy,
			  unsigned int target_freq,
			  unsigned int relation)
{
	unsigned int index, tmp;
	int ret = 0, i;
	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;

	mutex_lock(&cpufreq_lock);

	ret = cpufreq_frequency_table_target(policy, freq_table,
					   target_freq, relation, &index);
	if (ret)
		goto out;

	freqs.old = dvfs_info->cur_frequency;
	freqs.new = freq_table[index].frequency;

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

	/* Set the target frequency in all C0_3_PSTATE register */
	for_each_cpu(i, policy->cpus) {
		tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + i * 4);
		tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT);
		tmp |= (index << C0_3_PSTATE_NEW_SHIFT);

		__raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + i * 4);
	}
out:
	mutex_unlock(&cpufreq_lock);
	return ret;
}

static void exynos_cpufreq_work(struct work_struct *work)
{
	unsigned int cur_pstate, index;
	struct cpufreq_policy *policy = cpufreq_cpu_get(0); /* boot CPU */
	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;

	/* Ensure we can access cpufreq structures */
	if (unlikely(dvfs_info->dvfs_enabled == false))
		goto skip_work;

	mutex_lock(&cpufreq_lock);
	freqs.old = dvfs_info->cur_frequency;

	cur_pstate = __raw_readl(dvfs_info->base + XMU_P_STATUS);
	if (cur_pstate >> C0_3_PSTATE_VALID_SHIFT & 0x1)
		index = (cur_pstate >> C0_3_PSTATE_CURR_SHIFT) & P_VALUE_MASK;
	else
		index = (cur_pstate >> C0_3_PSTATE_NEW_SHIFT) & P_VALUE_MASK;

	if (likely(index < dvfs_info->freq_count)) {
		freqs.new = freq_table[index].frequency;
		dvfs_info->cur_frequency = freqs.new;
	} else {
		dev_crit(dvfs_info->dev, "New frequency out of range\n");
		freqs.new = dvfs_info->cur_frequency;
	}
	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

	cpufreq_cpu_put(policy);
	mutex_unlock(&cpufreq_lock);
skip_work:
	enable_irq(dvfs_info->irq);
}

static irqreturn_t exynos_cpufreq_irq(int irq, void *id)
{
	unsigned int tmp;

	tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQ);
	if (tmp >> PSTATE_CHANGED_SHIFT & 0x1) {
		__raw_writel(tmp, dvfs_info->base + XMU_PMUIRQ);
		disable_irq_nosync(irq);
		schedule_work(&dvfs_info->irq_work);
	}
	return IRQ_HANDLED;
}

static void exynos_sort_descend_freq_table(void)
{
	struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
	int i = 0, index;
	unsigned int tmp_freq;
	/*
	 * Exynos5440 clock controller state logic expects the cpufreq table to
	 * be in descending order. But the OPP library constructs the table in
	 * ascending order. So to make the table descending we just need to
	 * swap the i element with the N - i element.
	 */
	for (i = 0; i < dvfs_info->freq_count / 2; i++) {
		index = dvfs_info->freq_count - i - 1;
		tmp_freq = freq_tbl[i].frequency;
		freq_tbl[i].frequency = freq_tbl[index].frequency;
		freq_tbl[index].frequency = tmp_freq;
	}
}

static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
	int ret;

	ret = cpufreq_frequency_table_cpuinfo(policy, dvfs_info->freq_table);
	if (ret) {
		dev_err(dvfs_info->dev, "Invalid frequency table: %d\n", ret);
		return ret;
	}

	policy->cur = dvfs_info->cur_frequency;
	policy->cpuinfo.transition_latency = dvfs_info->latency;
	cpumask_setall(policy->cpus);

	cpufreq_frequency_table_get_attr(dvfs_info->freq_table, policy->cpu);

	return 0;
}

static struct cpufreq_driver exynos_driver = {
	.flags		= CPUFREQ_STICKY,
	.verify		= exynos_verify_speed,
	.target		= exynos_target,
	.get		= exynos_getspeed,
	.init		= exynos_cpufreq_cpu_init,
	.name		= CPUFREQ_NAME,
};

static const struct of_device_id exynos_cpufreq_match[] = {
	{
		.compatible = "samsung,exynos5440-cpufreq",
	},
	{},
};
MODULE_DEVICE_TABLE(of, exynos_cpufreq_match);

static int exynos_cpufreq_probe(struct platform_device *pdev)
{
	int ret = -EINVAL;
	struct device_node *np;
	struct resource res;

	np =  pdev->dev.of_node;
	if (!np)
		return -ENODEV;

	dvfs_info = devm_kzalloc(&pdev->dev, sizeof(*dvfs_info), GFP_KERNEL);
	if (!dvfs_info) {
		ret = -ENOMEM;
		goto err_put_node;
	}

	dvfs_info->dev = &pdev->dev;

	ret = of_address_to_resource(np, 0, &res);
	if (ret)
		goto err_put_node;

	dvfs_info->base = devm_ioremap_resource(dvfs_info->dev, &res);
	if (IS_ERR(dvfs_info->base)) {
		ret = PTR_ERR(dvfs_info->base);
		goto err_put_node;
	}

	dvfs_info->irq = irq_of_parse_and_map(np, 0);
	if (!dvfs_info->irq) {
		dev_err(dvfs_info->dev, "No cpufreq irq found\n");
		ret = -ENODEV;
		goto err_put_node;
	}

	ret = of_init_opp_table(dvfs_info->dev);
	if (ret) {
		dev_err(dvfs_info->dev, "failed to init OPP table: %d\n", ret);
		goto err_put_node;
	}

	ret = opp_init_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
	if (ret) {
		dev_err(dvfs_info->dev,
			"failed to init cpufreq table: %d\n", ret);
		goto err_put_node;
	}
	dvfs_info->freq_count = opp_get_opp_count(dvfs_info->dev);
	exynos_sort_descend_freq_table();

	if (of_property_read_u32(np, "clock-latency", &dvfs_info->latency))
		dvfs_info->latency = DEF_TRANS_LATENCY;

	dvfs_info->cpu_clk = devm_clk_get(dvfs_info->dev, "armclk");
	if (IS_ERR(dvfs_info->cpu_clk)) {
		dev_err(dvfs_info->dev, "Failed to get cpu clock\n");
		ret = PTR_ERR(dvfs_info->cpu_clk);
		goto err_free_table;
	}

	dvfs_info->cur_frequency = clk_get_rate(dvfs_info->cpu_clk);
	if (!dvfs_info->cur_frequency) {
		dev_err(dvfs_info->dev, "Failed to get clock rate\n");
		ret = -EINVAL;
		goto err_free_table;
	}
	dvfs_info->cur_frequency /= 1000;

	INIT_WORK(&dvfs_info->irq_work, exynos_cpufreq_work);
	ret = devm_request_irq(dvfs_info->dev, dvfs_info->irq,
				exynos_cpufreq_irq, IRQF_TRIGGER_NONE,
				CPUFREQ_NAME, dvfs_info);
	if (ret) {
		dev_err(dvfs_info->dev, "Failed to register IRQ\n");
		goto err_free_table;
	}

	ret = init_div_table();
	if (ret) {
		dev_err(dvfs_info->dev, "Failed to initialise div table\n");
		goto err_free_table;
	}

	exynos_enable_dvfs();
	ret = cpufreq_register_driver(&exynos_driver);
	if (ret) {
		dev_err(dvfs_info->dev,
			"%s: failed to register cpufreq driver\n", __func__);
		goto err_free_table;
	}

	of_node_put(np);
	dvfs_info->dvfs_enabled = true;
	return 0;

err_free_table:
	opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
err_put_node:
	of_node_put(np);
	dev_err(dvfs_info->dev, "%s: failed initialization\n", __func__);
	return ret;
}

static int exynos_cpufreq_remove(struct platform_device *pdev)
{
	cpufreq_unregister_driver(&exynos_driver);
	opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
	return 0;
}

static struct platform_driver exynos_cpufreq_platdrv = {
	.driver = {
		.name	= "exynos5440-cpufreq",
		.owner	= THIS_MODULE,
		.of_match_table = exynos_cpufreq_match,
	},
	.probe		= exynos_cpufreq_probe,
	.remove		= exynos_cpufreq_remove,
};
module_platform_driver(exynos_cpufreq_platdrv);

MODULE_AUTHOR("Amit Daniel Kachhap <amit.daniel@samsung.com>");
MODULE_DESCRIPTION("Exynos5440 cpufreq driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
49d7b5bf ADK	1	/*
	2	* Copyright (c) 2013 Samsung Electronics Co., Ltd.
	3	* http://www.samsung.com
	4	*
	5	* Amit Daniel Kachhap <amit.daniel@samsung.com>
	6	*
	7	* EXYNOS5440 - CPU frequency scaling support
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/clk.h>
	15	#include <linux/cpu.h>
	16	#include <linux/cpufreq.h>
	17	#include <linux/err.h>
	18	#include <linux/interrupt.h>
	19	#include <linux/io.h>
	20	#include <linux/module.h>
	21	#include <linux/of_address.h>
	22	#include <linux/of_irq.h>
	23	#include <linux/opp.h>
	24	#include <linux/platform_device.h>
	25	#include <linux/slab.h>
	26
	27	/* Register definitions */
	28	#define XMU_DVFS_CTRL 0x0060
	29	#define XMU_PMU_P0_7 0x0064
	30	#define XMU_C0_3_PSTATE 0x0090
	31	#define XMU_P_LIMIT 0x00a0
	32	#define XMU_P_STATUS 0x00a4
	33	#define XMU_PMUEVTEN 0x00d0
	34	#define XMU_PMUIRQEN 0x00d4
	35	#define XMU_PMUIRQ 0x00d8
	36
	37	/* PMU mask and shift definations */
	38	#define P_VALUE_MASK 0x7
	39
	40	#define XMU_DVFS_CTRL_EN_SHIFT 0
	41
	42	#define P0_7_CPUCLKDEV_SHIFT 21
	43	#define P0_7_CPUCLKDEV_MASK 0x7
	44	#define P0_7_ATBCLKDEV_SHIFT 18
	45	#define P0_7_ATBCLKDEV_MASK 0x7
	46	#define P0_7_CSCLKDEV_SHIFT 15
	47	#define P0_7_CSCLKDEV_MASK 0x7
	48	#define P0_7_CPUEMA_SHIFT 28
	49	#define P0_7_CPUEMA_MASK 0xf
	50	#define P0_7_L2EMA_SHIFT 24
	51	#define P0_7_L2EMA_MASK 0xf
	52	#define P0_7_VDD_SHIFT 8
	53	#define P0_7_VDD_MASK 0x7f
	54	#define P0_7_FREQ_SHIFT 0
	55	#define P0_7_FREQ_MASK 0xff
	56
	57	#define C0_3_PSTATE_VALID_SHIFT 8
	58	#define C0_3_PSTATE_CURR_SHIFT 4
	59	#define C0_3_PSTATE_NEW_SHIFT 0
	60
	61	#define PSTATE_CHANGED_EVTEN_SHIFT 0
	62
	63	#define PSTATE_CHANGED_IRQEN_SHIFT 0
	64
65	#define PSTATE_CHANGED_SHIFT 0
66
67	/* some constant values for clock divider calculation */
68	#define CPU_DIV_FREQ_MAX 500
69	#define CPU_DBG_FREQ_MAX 375
70	#define CPU_ATB_FREQ_MAX 500
71
72	#define PMIC_LOW_VOLT 0x30
73	#define PMIC_HIGH_VOLT 0x28
74
75	#define CPUEMA_HIGH 0x2
76	#define CPUEMA_MID 0x4
77	#define CPUEMA_LOW 0x7
78
79	#define L2EMA_HIGH 0x1
80	#define L2EMA_MID 0x3
81	#define L2EMA_LOW 0x4
82
83	#define DIV_TAB_MAX 2
84	/* frequency unit is 20MHZ */
85	#define FREQ_UNIT 20
86	#define MAX_VOLTAGE 1550000 /* In microvolt */
87	#define VOLTAGE_STEP 12500 /* In microvolt */
88
89	#define CPUFREQ_NAME "exynos5440_dvfs"
90	#define DEF_TRANS_LATENCY 100000
91
92	enum cpufreq_level_index {
93	L0, L1, L2, L3, L4,
94	L5, L6, L7, L8, L9,
95	};
96	#define CPUFREQ_LEVEL_END (L7 + 1)
97
98	struct exynos_dvfs_data {
99	void __iomem *base;
100	struct resource *mem;
101	int irq;
102	struct clk *cpu_clk;
103	unsigned int cur_frequency;
104	unsigned int latency;
105	struct cpufreq_frequency_table *freq_table;
106	unsigned int freq_count;
107	struct device *dev;
108	bool dvfs_enabled;
109	struct work_struct irq_work;
110	};
111
112	static struct exynos_dvfs_data *dvfs_info;
113	static DEFINE_MUTEX(cpufreq_lock);
114	static struct cpufreq_freqs freqs;
115
116	static int init_div_table(void)
117	{
118	struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
119	unsigned int tmp, clk_div, ema_div, freq, volt_id;
120	int i = 0;
121	struct opp *opp;
122
123	for (i = 0; freq_tbl[i].frequency != CPUFREQ_TABLE_END; i++) {
124
125	opp = opp_find_freq_exact(dvfs_info->dev,
126	freq_tbl[i].frequency * 1000, true);
127	if (IS_ERR(opp)) {
128	dev_err(dvfs_info->dev,
129	"failed to find valid OPP for %u KHZ\n",
130	freq_tbl[i].frequency);
131	return PTR_ERR(opp);
132	}
133
134	freq = freq_tbl[i].frequency / 1000; /* In MHZ */
135	clk_div = ((freq / CPU_DIV_FREQ_MAX) & P0_7_CPUCLKDEV_MASK)
136	<< P0_7_CPUCLKDEV_SHIFT;
137	clk_div \|= ((freq / CPU_ATB_FREQ_MAX) & P0_7_ATBCLKDEV_MASK)
138	<< P0_7_ATBCLKDEV_SHIFT;
139	clk_div \|= ((freq / CPU_DBG_FREQ_MAX) & P0_7_CSCLKDEV_MASK)
140	<< P0_7_CSCLKDEV_SHIFT;
141
142	/* Calculate EMA */
143	volt_id = opp_get_voltage(opp);
144	volt_id = (MAX_VOLTAGE - volt_id) / VOLTAGE_STEP;
145	if (volt_id < PMIC_HIGH_VOLT) {
146	ema_div = (CPUEMA_HIGH << P0_7_CPUEMA_SHIFT) \|
147	(L2EMA_HIGH << P0_7_L2EMA_SHIFT);
148	} else if (volt_id > PMIC_LOW_VOLT) {
149	ema_div = (CPUEMA_LOW << P0_7_CPUEMA_SHIFT) \|
150	(L2EMA_LOW << P0_7_L2EMA_SHIFT);
151	} else {
152	ema_div = (CPUEMA_MID << P0_7_CPUEMA_SHIFT) \|
153	(L2EMA_MID << P0_7_L2EMA_SHIFT);
154	}
155
156	tmp = (clk_div \| ema_div \| (volt_id << P0_7_VDD_SHIFT)
157	\| ((freq / FREQ_UNIT) << P0_7_FREQ_SHIFT));
158
159	__raw_writel(tmp, dvfs_info->base + XMU_PMU_P0_7 + 4 * i);
160	}
161
162	return 0;
163	}
164
165	static void exynos_enable_dvfs(void)
166	{
167	unsigned int tmp, i, cpu;
168	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
169	/* Disable DVFS */
170	__raw_writel(0, dvfs_info->base + XMU_DVFS_CTRL);
171
172	/* Enable PSTATE Change Event */
173	tmp = __raw_readl(dvfs_info->base + XMU_PMUEVTEN);
174	tmp \|= (1 << PSTATE_CHANGED_EVTEN_SHIFT);
175	__raw_writel(tmp, dvfs_info->base + XMU_PMUEVTEN);
176
177	/* Enable PSTATE Change IRQ */
178	tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQEN);
179	tmp \|= (1 << PSTATE_CHANGED_IRQEN_SHIFT);
180	__raw_writel(tmp, dvfs_info->base + XMU_PMUIRQEN);
181
182	/* Set initial performance index */
183	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
184	if (freq_table[i].frequency == dvfs_info->cur_frequency)
185	break;
186
187	if (freq_table[i].frequency == CPUFREQ_TABLE_END) {
188	dev_crit(dvfs_info->dev, "Boot up frequency not supported\n");
189	/* Assign the highest frequency */
190	i = 0;
191	dvfs_info->cur_frequency = freq_table[i].frequency;
192	}
193
194	dev_info(dvfs_info->dev, "Setting dvfs initial frequency = %uKHZ",
195	dvfs_info->cur_frequency);
196
197	for (cpu = 0; cpu < CONFIG_NR_CPUS; cpu++) {
198	tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4);
199	tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT);
200	tmp \|= (i << C0_3_PSTATE_NEW_SHIFT);
201	__raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + cpu * 4);
202	}
203
204	/* Enable DVFS */
205	__raw_writel(1 << XMU_DVFS_CTRL_EN_SHIFT,
206	dvfs_info->base + XMU_DVFS_CTRL);
207	}
208
209	static int exynos_verify_speed(struct cpufreq_policy *policy)
210	{
211	return cpufreq_frequency_table_verify(policy,
212	dvfs_info->freq_table);
213	}
214
215	static unsigned int exynos_getspeed(unsigned int cpu)
216	{
217	return dvfs_info->cur_frequency;
218	}
219
220	static int exynos_target(struct cpufreq_policy *policy,
221	unsigned int target_freq,
222	unsigned int relation)
223	{
224	unsigned int index, tmp;
225	int ret = 0, i;
226	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
227
228	mutex_lock(&cpufreq_lock);
229
230	ret = cpufreq_frequency_table_target(policy, freq_table,
231	target_freq, relation, &index);
232	if (ret)
233	goto out;
234
235	freqs.old = dvfs_info->cur_frequency;
236	freqs.new = freq_table[index].frequency;
237
238	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
239
240	/* Set the target frequency in all C0_3_PSTATE register */
241	for_each_cpu(i, policy->cpus) {
242	tmp = __raw_readl(dvfs_info->base + XMU_C0_3_PSTATE + i * 4);
243	tmp &= ~(P_VALUE_MASK << C0_3_PSTATE_NEW_SHIFT);
244	tmp \|= (index << C0_3_PSTATE_NEW_SHIFT);
245
246	__raw_writel(tmp, dvfs_info->base + XMU_C0_3_PSTATE + i * 4);
247	}
248	out:
249	mutex_unlock(&cpufreq_lock);
250	return ret;
251	}
252
253	static void exynos_cpufreq_work(struct work_struct *work)
254	{
255	unsigned int cur_pstate, index;
256	struct cpufreq_policy policy = cpufreq_cpu_get(0); / boot CPU */
257	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
258
259	/* Ensure we can access cpufreq structures */
260	if (unlikely(dvfs_info->dvfs_enabled == false))
261	goto skip_work;
262
263	mutex_lock(&cpufreq_lock);
264	freqs.old = dvfs_info->cur_frequency;
265
266	cur_pstate = __raw_readl(dvfs_info->base + XMU_P_STATUS);
267	if (cur_pstate >> C0_3_PSTATE_VALID_SHIFT & 0x1)
268	index = (cur_pstate >> C0_3_PSTATE_CURR_SHIFT) & P_VALUE_MASK;
269	else
270	index = (cur_pstate >> C0_3_PSTATE_NEW_SHIFT) & P_VALUE_MASK;
271
272	if (likely(index < dvfs_info->freq_count)) {
273	freqs.new = freq_table[index].frequency;
274	dvfs_info->cur_frequency = freqs.new;
275	} else {
276	dev_crit(dvfs_info->dev, "New frequency out of range\n");
277	freqs.new = dvfs_info->cur_frequency;
278	}
279	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
280
281	cpufreq_cpu_put(policy);
282	mutex_unlock(&cpufreq_lock);
283	skip_work:
284	enable_irq(dvfs_info->irq);
285	}
286
287	static irqreturn_t exynos_cpufreq_irq(int irq, void *id)
288	{
289	unsigned int tmp;
290
291	tmp = __raw_readl(dvfs_info->base + XMU_PMUIRQ);
292	if (tmp >> PSTATE_CHANGED_SHIFT & 0x1) {
293	__raw_writel(tmp, dvfs_info->base + XMU_PMUIRQ);
294	disable_irq_nosync(irq);
295	schedule_work(&dvfs_info->irq_work);
296	}
297	return IRQ_HANDLED;
298	}
299
300	static void exynos_sort_descend_freq_table(void)
301	{
302	struct cpufreq_frequency_table *freq_tbl = dvfs_info->freq_table;
303	int i = 0, index;
304	unsigned int tmp_freq;
305	/*
306	* Exynos5440 clock controller state logic expects the cpufreq table to
307	* be in descending order. But the OPP library constructs the table in
308	* ascending order. So to make the table descending we just need to
309	* swap the i element with the N - i element.
310	*/
311	for (i = 0; i < dvfs_info->freq_count / 2; i++) {
312	index = dvfs_info->freq_count - i - 1;
313	tmp_freq = freq_tbl[i].frequency;
314	freq_tbl[i].frequency = freq_tbl[index].frequency;
315	freq_tbl[index].frequency = tmp_freq;
316	}
317	}
318
319	static int exynos_cpufreq_cpu_init(struct cpufreq_policy *policy)
320	{
321	int ret;
322
323	ret = cpufreq_frequency_table_cpuinfo(policy, dvfs_info->freq_table);
324	if (ret) {
325	dev_err(dvfs_info->dev, "Invalid frequency table: %d\n", ret);
326	return ret;
327	}
328
329	policy->cur = dvfs_info->cur_frequency;
330	policy->cpuinfo.transition_latency = dvfs_info->latency;
331	cpumask_setall(policy->cpus);
332
333	cpufreq_frequency_table_get_attr(dvfs_info->freq_table, policy->cpu);
334
335	return 0;
336	}
337
338	static struct cpufreq_driver exynos_driver = {
339	.flags = CPUFREQ_STICKY,
340	.verify = exynos_verify_speed,
341	.target = exynos_target,
342	.get = exynos_getspeed,
343	.init = exynos_cpufreq_cpu_init,
344	.name = CPUFREQ_NAME,
345	};
346
347	static const struct of_device_id exynos_cpufreq_match[] = {
348	{
349	.compatible = "samsung,exynos5440-cpufreq",
350	},
351	{},
352	};
353	MODULE_DEVICE_TABLE(of, exynos_cpufreq_match);
354
355	static int exynos_cpufreq_probe(struct platform_device *pdev)
356	{
357	int ret = -EINVAL;
358	struct device_node *np;
359	struct resource res;
360
361	np = pdev->dev.of_node;
362	if (!np)
363	return -ENODEV;
364
365	dvfs_info = devm_kzalloc(&pdev->dev, sizeof(*dvfs_info), GFP_KERNEL);
366	if (!dvfs_info) {
367	ret = -ENOMEM;
368	goto err_put_node;
369	}
370
371	dvfs_info->dev = &pdev->dev;
372
373	ret = of_address_to_resource(np, 0, &res);
374	if (ret)
375	goto err_put_node;
376
377	dvfs_info->base = devm_ioremap_resource(dvfs_info->dev, &res);
378	if (IS_ERR(dvfs_info->base)) {
379	ret = PTR_ERR(dvfs_info->base);
380	goto err_put_node;
381	}
382
383	dvfs_info->irq = irq_of_parse_and_map(np, 0);
384	if (!dvfs_info->irq) {
385	dev_err(dvfs_info->dev, "No cpufreq irq found\n");
386	ret = -ENODEV;
387	goto err_put_node;
388	}
389
390	ret = of_init_opp_table(dvfs_info->dev);
391	if (ret) {
392	dev_err(dvfs_info->dev, "failed to init OPP table: %d\n", ret);
393	goto err_put_node;
394	}
395
396	ret = opp_init_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
397	if (ret) {
398	dev_err(dvfs_info->dev,
399	"failed to init cpufreq table: %d\n", ret);
400	goto err_put_node;
401	}
402	dvfs_info->freq_count = opp_get_opp_count(dvfs_info->dev);
403	exynos_sort_descend_freq_table();
404
405	if (of_property_read_u32(np, "clock-latency", &dvfs_info->latency))
406	dvfs_info->latency = DEF_TRANS_LATENCY;
407
408	dvfs_info->cpu_clk = devm_clk_get(dvfs_info->dev, "armclk");
409	if (IS_ERR(dvfs_info->cpu_clk)) {
410	dev_err(dvfs_info->dev, "Failed to get cpu clock\n");
411	ret = PTR_ERR(dvfs_info->cpu_clk);
412	goto err_free_table;
413	}
414
415	dvfs_info->cur_frequency = clk_get_rate(dvfs_info->cpu_clk);
416	if (!dvfs_info->cur_frequency) {
417	dev_err(dvfs_info->dev, "Failed to get clock rate\n");
418	ret = -EINVAL;
419	goto err_free_table;
420	}
421	dvfs_info->cur_frequency /= 1000;
422
423	INIT_WORK(&dvfs_info->irq_work, exynos_cpufreq_work);
424	ret = devm_request_irq(dvfs_info->dev, dvfs_info->irq,
425	exynos_cpufreq_irq, IRQF_TRIGGER_NONE,
426	CPUFREQ_NAME, dvfs_info);
427	if (ret) {
428	dev_err(dvfs_info->dev, "Failed to register IRQ\n");
429	goto err_free_table;
430	}
431
432	ret = init_div_table();
433	if (ret) {
434	dev_err(dvfs_info->dev, "Failed to initialise div table\n");
435	goto err_free_table;
436	}
437
438	exynos_enable_dvfs();
439	ret = cpufreq_register_driver(&exynos_driver);
440	if (ret) {
441	dev_err(dvfs_info->dev,
442	"%s: failed to register cpufreq driver\n", __func__);
443	goto err_free_table;
444	}
445
446	of_node_put(np);
447	dvfs_info->dvfs_enabled = true;
448	return 0;
449
450	err_free_table:
451	opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
452	err_put_node:
453	of_node_put(np);
454	dev_err(dvfs_info->dev, "%s: failed initialization\n", __func__);
455	return ret;
456	}
457
458	static int exynos_cpufreq_remove(struct platform_device *pdev)
459	{
460	cpufreq_unregister_driver(&exynos_driver);
461	opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
462	return 0;
463	}
464
465	static struct platform_driver exynos_cpufreq_platdrv = {
466	.driver = {
467	.name = "exynos5440-cpufreq",
468	.owner = THIS_MODULE,
469	.of_match_table = exynos_cpufreq_match,
470	},
471	.probe = exynos_cpufreq_probe,
472	.remove = exynos_cpufreq_remove,
473	};
474	module_platform_driver(exynos_cpufreq_platdrv);
475
476	MODULE_AUTHOR("Amit Daniel Kachhap <amit.daniel@samsung.com>");
477	MODULE_DESCRIPTION("Exynos5440 cpufreq driver");
478	MODULE_LICENSE("GPL");