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path: root/drivers/cpufreq/exynos5440-cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/exynos5440-cpufreq.c')
-rw-r--r--drivers/cpufreq/exynos5440-cpufreq.c481
1 files changed, 481 insertions, 0 deletions
diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c
new file mode 100644
index 000000000000..0c74018eda47
--- /dev/null
+++ b/drivers/cpufreq/exynos5440-cpufreq.c
@@ -0,0 +1,481 @@
+/*
+ * 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;
+
+ rcu_read_lock();
+ 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)) {
+ rcu_read_unlock();
+ 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);
+ }
+
+ rcu_read_unlock();
+ 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");