diff options
Diffstat (limited to 'drivers/devfreq/exynos/exynos5_bus.c')
| -rw-r--r-- | drivers/devfreq/exynos/exynos5_bus.c | 503 |
1 files changed, 503 insertions, 0 deletions
diff --git a/drivers/devfreq/exynos/exynos5_bus.c b/drivers/devfreq/exynos/exynos5_bus.c new file mode 100644 index 00000000000..574b16b59be --- /dev/null +++ b/drivers/devfreq/exynos/exynos5_bus.c @@ -0,0 +1,503 @@ +/* + * Copyright (c) 2012 Samsung Electronics Co., Ltd. + * http://www.samsung.com/ + * + * EXYNOS5 INT clock frequency scaling support using DEVFREQ framework + * Based on work done by Jonghwan Choi <jhbird.choi@samsung.com> + * Support for only EXYNOS5250 is present. + * + * 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/module.h> +#include <linux/devfreq.h> +#include <linux/io.h> +#include <linux/opp.h> +#include <linux/slab.h> +#include <linux/suspend.h> +#include <linux/opp.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/platform_device.h> +#include <linux/pm_qos.h> +#include <linux/regulator/consumer.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> + +#include "exynos_ppmu.h" + +#define MAX_SAFEVOLT 1100000 /* 1.10V */ +/* Assume that the bus is saturated if the utilization is 25% */ +#define INT_BUS_SATURATION_RATIO 25 + +enum int_level_idx { + LV_0, + LV_1, + LV_2, + LV_3, + LV_4, + _LV_END +}; + +enum exynos_ppmu_list { + PPMU_RIGHT, + PPMU_END, +}; + +struct busfreq_data_int { + struct device *dev; + struct devfreq *devfreq; + struct regulator *vdd_int; + struct exynos_ppmu ppmu[PPMU_END]; + unsigned long curr_freq; + bool disabled; + + struct notifier_block pm_notifier; + struct mutex lock; + struct pm_qos_request int_req; + struct clk *int_clk; +}; + +struct int_bus_opp_table { + unsigned int idx; + unsigned long clk; + unsigned long volt; +}; + +static struct int_bus_opp_table exynos5_int_opp_table[] = { + {LV_0, 266000, 1025000}, + {LV_1, 200000, 1025000}, + {LV_2, 160000, 1025000}, + {LV_3, 133000, 1025000}, + {LV_4, 100000, 1025000}, + {0, 0, 0}, +}; + +static void busfreq_mon_reset(struct busfreq_data_int *data) +{ + unsigned int i; + + for (i = PPMU_RIGHT; i < PPMU_END; i++) { + void __iomem *ppmu_base = data->ppmu[i].hw_base; + + /* Reset the performance and cycle counters */ + exynos_ppmu_reset(ppmu_base); + + /* Setup count registers to monitor read/write transactions */ + data->ppmu[i].event[PPMU_PMNCNT3] = RDWR_DATA_COUNT; + exynos_ppmu_setevent(ppmu_base, PPMU_PMNCNT3, + data->ppmu[i].event[PPMU_PMNCNT3]); + + exynos_ppmu_start(ppmu_base); + } +} + +static void exynos5_read_ppmu(struct busfreq_data_int *data) +{ + int i, j; + + for (i = PPMU_RIGHT; i < PPMU_END; i++) { + void __iomem *ppmu_base = data->ppmu[i].hw_base; + + exynos_ppmu_stop(ppmu_base); + + /* Update local data from PPMU */ + data->ppmu[i].ccnt = __raw_readl(ppmu_base + PPMU_CCNT); + + for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) { + if (data->ppmu[i].event[j] == 0) + data->ppmu[i].count[j] = 0; + else + data->ppmu[i].count[j] = + exynos_ppmu_read(ppmu_base, j); + } + } + + busfreq_mon_reset(data); +} + +static int exynos5_int_setvolt(struct busfreq_data_int *data, + unsigned long volt) +{ + return regulator_set_voltage(data->vdd_int, volt, MAX_SAFEVOLT); +} + +static int exynos5_busfreq_int_target(struct device *dev, unsigned long *_freq, + u32 flags) +{ + int err = 0; + struct platform_device *pdev = container_of(dev, struct platform_device, + dev); + struct busfreq_data_int *data = platform_get_drvdata(pdev); + struct opp *opp; + unsigned long old_freq, freq; + unsigned long volt; + + rcu_read_lock(); + opp = devfreq_recommended_opp(dev, _freq, flags); + if (IS_ERR(opp)) { + rcu_read_unlock(); + dev_err(dev, "%s: Invalid OPP.\n", __func__); + return PTR_ERR(opp); + } + + freq = opp_get_freq(opp); + volt = opp_get_voltage(opp); + rcu_read_unlock(); + + old_freq = data->curr_freq; + + if (old_freq == freq) + return 0; + + dev_dbg(dev, "targetting %lukHz %luuV\n", freq, volt); + + mutex_lock(&data->lock); + + if (data->disabled) + goto out; + + if (freq > exynos5_int_opp_table[0].clk) + pm_qos_update_request(&data->int_req, freq * 16 / 1000); + else + pm_qos_update_request(&data->int_req, -1); + + if (old_freq < freq) + err = exynos5_int_setvolt(data, volt); + if (err) + goto out; + + err = clk_set_rate(data->int_clk, freq * 1000); + + if (err) + goto out; + + if (old_freq > freq) + err = exynos5_int_setvolt(data, volt); + if (err) + goto out; + + data->curr_freq = freq; +out: + mutex_unlock(&data->lock); + return err; +} + +static int exynos5_get_busier_dmc(struct busfreq_data_int *data) +{ + int i, j; + int busy = 0; + unsigned int temp = 0; + + for (i = PPMU_RIGHT; i < PPMU_END; i++) { + for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) { + if (data->ppmu[i].count[j] > temp) { + temp = data->ppmu[i].count[j]; + busy = i; + } + } + } + + return busy; +} + +static int exynos5_int_get_dev_status(struct device *dev, + struct devfreq_dev_status *stat) +{ + struct platform_device *pdev = container_of(dev, struct platform_device, + dev); + struct busfreq_data_int *data = platform_get_drvdata(pdev); + int busier_dmc; + + exynos5_read_ppmu(data); + busier_dmc = exynos5_get_busier_dmc(data); + + stat->current_frequency = data->curr_freq; + + /* Number of cycles spent on memory access */ + stat->busy_time = data->ppmu[busier_dmc].count[PPMU_PMNCNT3]; + stat->busy_time *= 100 / INT_BUS_SATURATION_RATIO; + stat->total_time = data->ppmu[busier_dmc].ccnt; + + return 0; +} +static void exynos5_int_exit(struct device *dev) +{ + struct platform_device *pdev = container_of(dev, struct platform_device, + dev); + struct busfreq_data_int *data = platform_get_drvdata(pdev); + + devfreq_unregister_opp_notifier(dev, data->devfreq); +} + +static struct devfreq_dev_profile exynos5_devfreq_int_profile = { + .initial_freq = 160000, + .polling_ms = 100, + .target = exynos5_busfreq_int_target, + .get_dev_status = exynos5_int_get_dev_status, + .exit = exynos5_int_exit, +}; + +static int exynos5250_init_int_tables(struct busfreq_data_int *data) +{ + int i, err = 0; + + for (i = LV_0; i < _LV_END; i++) { + err = opp_add(data->dev, exynos5_int_opp_table[i].clk, + exynos5_int_opp_table[i].volt); + if (err) { + dev_err(data->dev, "Cannot add opp entries.\n"); + return err; + } + } + + return 0; +} + +static int exynos5_busfreq_int_pm_notifier_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct busfreq_data_int *data = container_of(this, + struct busfreq_data_int, pm_notifier); + struct opp *opp; + unsigned long maxfreq = ULONG_MAX; + unsigned long freq; + unsigned long volt; + int err = 0; + + switch (event) { + case PM_SUSPEND_PREPARE: + /* Set Fastest and Deactivate DVFS */ + mutex_lock(&data->lock); + + data->disabled = true; + + rcu_read_lock(); + opp = opp_find_freq_floor(data->dev, &maxfreq); + if (IS_ERR(opp)) { + rcu_read_unlock(); + err = PTR_ERR(opp); + goto unlock; + } + freq = opp_get_freq(opp); + volt = opp_get_voltage(opp); + rcu_read_unlock(); + + err = exynos5_int_setvolt(data, volt); + if (err) + goto unlock; + + err = clk_set_rate(data->int_clk, freq * 1000); + + if (err) + goto unlock; + + data->curr_freq = freq; +unlock: + mutex_unlock(&data->lock); + if (err) + return NOTIFY_BAD; + return NOTIFY_OK; + case PM_POST_RESTORE: + case PM_POST_SUSPEND: + /* Reactivate */ + mutex_lock(&data->lock); + data->disabled = false; + mutex_unlock(&data->lock); + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + +static int exynos5_busfreq_int_probe(struct platform_device *pdev) +{ + struct busfreq_data_int *data; + struct opp *opp; + struct device *dev = &pdev->dev; + struct device_node *np; + unsigned long initial_freq; + unsigned long initial_volt; + int err = 0; + int i; + + data = devm_kzalloc(&pdev->dev, sizeof(struct busfreq_data_int), + GFP_KERNEL); + if (data == NULL) { + dev_err(dev, "Cannot allocate memory.\n"); + return -ENOMEM; + } + + np = of_find_compatible_node(NULL, NULL, "samsung,exynos5250-ppmu"); + if (np == NULL) { + pr_err("Unable to find PPMU node\n"); + return -ENOENT; + } + + for (i = PPMU_RIGHT; i < PPMU_END; i++) { + /* map PPMU memory region */ + data->ppmu[i].hw_base = of_iomap(np, i); + if (data->ppmu[i].hw_base == NULL) { + dev_err(&pdev->dev, "failed to map memory region\n"); + return -ENOMEM; + } + } + data->pm_notifier.notifier_call = exynos5_busfreq_int_pm_notifier_event; + data->dev = dev; + mutex_init(&data->lock); + + err = exynos5250_init_int_tables(data); + if (err) + goto err_regulator; + + data->vdd_int = regulator_get(dev, "vdd_int"); + if (IS_ERR(data->vdd_int)) { + dev_err(dev, "Cannot get the regulator \"vdd_int\"\n"); + err = PTR_ERR(data->vdd_int); + goto err_regulator; + } + + data->int_clk = clk_get(dev, "int_clk"); + if (IS_ERR(data->int_clk)) { + dev_err(dev, "Cannot get clock \"int_clk\"\n"); + err = PTR_ERR(data->int_clk); + goto err_clock; + } + + rcu_read_lock(); + opp = opp_find_freq_floor(dev, + &exynos5_devfreq_int_profile.initial_freq); + if (IS_ERR(opp)) { + rcu_read_unlock(); + dev_err(dev, "Invalid initial frequency %lu kHz.\n", + exynos5_devfreq_int_profile.initial_freq); + err = PTR_ERR(opp); + goto err_opp_add; + } + initial_freq = opp_get_freq(opp); + initial_volt = opp_get_voltage(opp); + rcu_read_unlock(); + data->curr_freq = initial_freq; + + err = clk_set_rate(data->int_clk, initial_freq * 1000); + if (err) { + dev_err(dev, "Failed to set initial frequency\n"); + goto err_opp_add; + } + + err = exynos5_int_setvolt(data, initial_volt); + if (err) + goto err_opp_add; + + platform_set_drvdata(pdev, data); + + busfreq_mon_reset(data); + + data->devfreq = devfreq_add_device(dev, &exynos5_devfreq_int_profile, + "simple_ondemand", NULL); + + if (IS_ERR(data->devfreq)) { + err = PTR_ERR(data->devfreq); + goto err_devfreq_add; + } + + devfreq_register_opp_notifier(dev, data->devfreq); + + err = register_pm_notifier(&data->pm_notifier); + if (err) { + dev_err(dev, "Failed to setup pm notifier\n"); + goto err_devfreq_add; + } + + /* TODO: Add a new QOS class for int/mif bus */ + pm_qos_add_request(&data->int_req, PM_QOS_NETWORK_THROUGHPUT, -1); + + return 0; + +err_devfreq_add: + devfreq_remove_device(data->devfreq); + platform_set_drvdata(pdev, NULL); +err_opp_add: + clk_put(data->int_clk); +err_clock: + regulator_put(data->vdd_int); +err_regulator: + return err; +} + +static int exynos5_busfreq_int_remove(struct platform_device *pdev) +{ + struct busfreq_data_int *data = platform_get_drvdata(pdev); + + pm_qos_remove_request(&data->int_req); + unregister_pm_notifier(&data->pm_notifier); + devfreq_remove_device(data->devfreq); + regulator_put(data->vdd_int); + clk_put(data->int_clk); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static int exynos5_busfreq_int_resume(struct device *dev) +{ + struct platform_device *pdev = container_of(dev, struct platform_device, + dev); + struct busfreq_data_int *data = platform_get_drvdata(pdev); + + busfreq_mon_reset(data); + return 0; +} + +static const struct dev_pm_ops exynos5_busfreq_int_pm = { + .resume = exynos5_busfreq_int_resume, +}; + +/* platform device pointer for exynos5 devfreq device. */ +static struct platform_device *exynos5_devfreq_pdev; + +static struct platform_driver exynos5_busfreq_int_driver = { + .probe = exynos5_busfreq_int_probe, + .remove = exynos5_busfreq_int_remove, + .driver = { + .name = "exynos5-bus-int", + .owner = THIS_MODULE, + .pm = &exynos5_busfreq_int_pm, + }, +}; + +static int __init exynos5_busfreq_int_init(void) +{ + int ret; + + ret = platform_driver_register(&exynos5_busfreq_int_driver); + if (ret < 0) + goto out; + + exynos5_devfreq_pdev = + platform_device_register_simple("exynos5-bus-int", -1, NULL, 0); + if (IS_ERR_OR_NULL(exynos5_devfreq_pdev)) { + ret = PTR_ERR(exynos5_devfreq_pdev); + goto out1; + } + + return 0; +out1: + platform_driver_unregister(&exynos5_busfreq_int_driver); +out: + return ret; +} +late_initcall(exynos5_busfreq_int_init); + +static void __exit exynos5_busfreq_int_exit(void) +{ + platform_device_unregister(exynos5_devfreq_pdev); + platform_driver_unregister(&exynos5_busfreq_int_driver); +} +module_exit(exynos5_busfreq_int_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("EXYNOS5 busfreq driver with devfreq framework"); |