Initial import

1 files changed, 454 insertions, 0 deletions

diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c
new file mode 100644
index 000000000..21a90ed7f
--- /dev/null
+++ b/drivers/cpufreq/exynos5440-cpufreq.c
@@ -0,0 +1,454 @@
+/*
+ * 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/pm_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 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 *pos, *freq_tbl = dvfs_info->freq_table;
+	unsigned int tmp, clk_div, ema_div, freq, volt_id;
+	struct dev_pm_opp *opp;
+
+	rcu_read_lock();
+	cpufreq_for_each_entry(pos, freq_tbl) {
+		opp = dev_pm_opp_find_freq_exact(dvfs_info->dev,
+					pos->frequency * 1000, true);
+		if (IS_ERR(opp)) {
+			rcu_read_unlock();
+			dev_err(dvfs_info->dev,
+				"failed to find valid OPP for %u KHZ\n",
+				pos->frequency);
+			return PTR_ERR(opp);
+		}
+
+		freq = pos->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 = dev_pm_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 *
+						(pos - freq_tbl));
+	}
+
+	rcu_read_unlock();
+	return 0;
+}
+
+static void exynos_enable_dvfs(unsigned int cur_frequency)
+{
+	unsigned int tmp, cpu;
+	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
+	struct cpufreq_frequency_table *pos;
+	/* 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 */
+	cpufreq_for_each_entry(pos, freq_table)
+		if (pos->frequency == cur_frequency)
+			break;
+
+	if (pos->frequency == CPUFREQ_TABLE_END) {
+		dev_crit(dvfs_info->dev, "Boot up frequency not supported\n");
+		/* Assign the highest frequency */
+		pos = freq_table;
+		cur_frequency = pos->frequency;
+	}
+
+	dev_info(dvfs_info->dev, "Setting dvfs initial frequency = %uKHZ",
+						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 |= ((pos - freq_table) << 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_target(struct cpufreq_policy *policy, unsigned int index)
+{
+	unsigned int tmp;
+	int i;
+	struct cpufreq_frequency_table *freq_table = dvfs_info->freq_table;
+
+	mutex_lock(&cpufreq_lock);
+
+	freqs.old = policy->cur;
+	freqs.new = freq_table[index].frequency;
+
+	cpufreq_freq_transition_begin(policy, &freqs);
+
+	/* 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);
+	}
+	mutex_unlock(&cpufreq_lock);
+	return 0;
+}
+
+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 = policy->cur;
+
+	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;
+	} else {
+		dev_crit(dvfs_info->dev, "New frequency out of range\n");
+		freqs.new = freqs.old;
+	}
+	cpufreq_freq_transition_end(policy, &freqs, 0);
+
+	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)
+{
+	policy->clk = dvfs_info->cpu_clk;
+	return cpufreq_generic_init(policy, dvfs_info->freq_table,
+			dvfs_info->latency);
+}
+
+static struct cpufreq_driver exynos_driver = {
+	.flags		= CPUFREQ_STICKY | CPUFREQ_ASYNC_NOTIFICATION |
+				CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+	.verify		= cpufreq_generic_frequency_table_verify,
+	.target_index	= exynos_target,
+	.get		= cpufreq_generic_get,
+	.init		= exynos_cpufreq_cpu_init,
+	.name		= CPUFREQ_NAME,
+	.attr		= cpufreq_generic_attr,
+};
+
+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;
+	unsigned int cur_frequency;
+
+	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 = dev_pm_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_free_opp;
+	}
+	dvfs_info->freq_count = dev_pm_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;
+	}
+
+	cur_frequency = clk_get_rate(dvfs_info->cpu_clk);
+	if (!cur_frequency) {
+		dev_err(dvfs_info->dev, "Failed to get clock rate\n");
+		ret = -EINVAL;
+		goto err_free_table;
+	}
+	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(cur_frequency);
+	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:
+	dev_pm_opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
+err_free_opp:
+	of_free_opp_table(dvfs_info->dev);
+err_put_node:
+	of_node_put(np);
+	dev_err(&pdev->dev, "%s: failed initialization\n", __func__);
+	return ret;
+}
+
+static int exynos_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_driver(&exynos_driver);
+	dev_pm_opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table);
+	of_free_opp_table(dvfs_info->dev);
+	return 0;
+}
+
+static struct platform_driver exynos_cpufreq_platdrv = {
+	.driver = {
+		.name	= "exynos5440-cpufreq",
+		.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");