--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -100,6 +100,19 @@ config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
governor. If unsure have a look at the help section of the
driver. Fallback governor will be the performance governor.
+
+config CPU_FREQ_DEFAULT_GOV_LAGFREE
+ bool "lagfree"
+ select CPU_FREQ_GOV_LAGFREE
+ select CPU_FREQ_GOV_PERFORMANCE
+ help
+ Use the CPUFreq governor 'lagfree' as default. This allows
+ you to get a full dynamic frequency capable system by simply
+ loading your cpufreq low-level hardware driver.
+ Be aware that not all cpufreq drivers support the lagfree
+ governor. If unsure have a look at the help section of the
+ driver. Fallback governor will be the performance governor.
+
config CPU_FREQ_DEFAULT_GOV_INTERACTIVE
bool "interactive"
select CPU_FREQ_GOV_INTERACTIVE
@@ -206,6 +219,71 @@ config CPU_FREQ_GOV_CONSERVATIVE
If in doubt, say N.
+config CPU_FREQ_GOV_LAGFREE
+ tristate "'lagfree' cpufreq governor"
+ depends on CPU_FREQ
+ help
+ 'lagfree' - this driver is rather similar to the 'ondemand'
+ governor both in its source code and its purpose, the difference is
+ its optimisation for better suitability in a battery powered
+ environment. The frequency is gracefully increased and decreased
+ rather than jumping to 100% when speed is required.
+
+config LAGFREE_MAX_LOAD
+ int "Max CPU Load"
+ default 50
+ depends on CPU_FREQ_GOV_LAGFREE
+ help
+ CPU freq will be increased if measured load > max_cpu_load;
+
+config LAGFREE_MIN_LOAD
+ int "Min CPU Load"
+ default 15
+ depends on CPU_FREQ_GOV_LAGFREE
+ help
+ CPU freq will be decrease if measured load < min_cpu_load;
+
+config LAGFREE_FREQ_STEP_DOWN
+ int "Frequency Step Down"
+ default 108000
+ depends on CPU_FREQ_GOV_LAGFREE
+ help
+ Max freqeuncy delta when ramping down.
+
+config LAGFREE_FREQ_SLEEP_MAX
+ int "Max Sleep frequeny"
+ default 384000
+ depends on CPU_FREQ_GOV_LAGFREE
+ help
+ Max freqeuncy for screen off.
+
+config LAGFREE_FREQ_AWAKE_MIN
+ int "Min Awake frequeny"
+ default 384000
+ depends on CPU_FREQ_GOV_LAGFREE
+ help
+ Min freqeuncy for screen on.
+
+config LAGFREE_FREQ_STEP_UP_SLEEP_PERCENT
+ int "Freq step up percent sleep"
+ default 20
+ depends on CPU_FREQ_GOV_LAGFREE
+ help
+ Frequency percent to step up while screen off.
+
+config CPU_FREQ_MIN_TICKS
+ int "Ticks between governor polling interval."
+ default 10
+ help
+ Minimum number of ticks between polling interval for governors.
+
+config CPU_FREQ_SAMPLING_LATENCY_MULTIPLIER
+ int "Sampling rate multiplier for governors."
+ default 1000
+ help
+ Sampling latency rate multiplied by the cpu switch latency.
+ Affects governor polling.
+
config SEC_DVFS
bool "DVFS job"
default n
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -7,8 +7,9 @@ obj-$(CONFIG_CPU_FREQ_STAT)
obj-$(CONFIG_CPU_FREQ_GOV_PERFORMANCE) += cpufreq_performance.o
obj-$(CONFIG_CPU_FREQ_GOV_POWERSAVE) += cpufreq_powersave.o
obj-$(CONFIG_CPU_FREQ_GOV_USERSPACE) += cpufreq_userspace.o
-obj-$(CONFIG_CPU_FREQ_GOV_ONDEMAND) += cpufreq_ondemand.o
+obj-$(CONFIG_CPU_FREQ_GOV_ONDEMAND) += cpufreq_ondemand.o
obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE) += cpufreq_conservative.o
+obj-$(CONFIG_CPU_FREQ_GOV_LAGFREE) += cpufreq_lagfree.o
obj-$(CONFIG_CPU_FREQ_GOV_INTERACTIVE) += cpufreq_interactive.o
# CPUfreq cross-arch helpers
--- /dev/null
+++ b/drivers/cpufreq/cpufreq_lagfree.c
@@ -0,0 +1,718 @@
+/*
+ * drivers/cpufreq/cpufreq_lagfree.c
+ *
+ * Copyright (C) 2001 Russell King
+ * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
+ * Jun Nakajima <jun.nakajima@intel.com>
+ * (C) 2004 Alexander Clouter <alex-kernel@digriz.org.uk>
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ctype.h>
+#include <linux/cpufreq.h>
+#include <linux/sysctl.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/sysfs.h>
+#include <linux/cpu.h>
+#include <linux/kmod.h>
+#include <linux/workqueue.h>
+#include <linux/jiffies.h>
+#include <linux/kernel_stat.h>
+#include <linux/percpu.h>
+#include <linux/mutex.h>
+#include <linux/earlysuspend.h>
+/*
+ * dbs is used in this file as a shortform for demandbased switching
+ * It helps to keep variable names smaller, simpler
+ */
+
+#define DEF_FREQUENCY_UP_THRESHOLD CONFIG_LAGFREE_MAX_LOAD
+#define DEF_FREQUENCY_DOWN_THRESHOLD CONFIG_LAGFREE_MIN_LOAD
+#define FREQ_STEP_DOWN CONFIG_LAGFREE_FREQ_STEP_DOWN
+#define FREQ_SLEEP_MAX CONFIG_LAGFREE_FREQ_SLEEP_MAX
+#define FREQ_AWAKE_MIN CONFIG_LAGFREE_FREQ_AWAKE_MIN
+#define FREQ_STEP_UP_SLEEP_PERCENT CONFIG_LAGFREE_FREQ_STEP_UP_SLEEP_PERCENT
+
+/*
+ * The polling frequency of this governor depends on the capability of
+ * the processor. Default polling frequency is 1000 times the transition
+ * latency of the processor. The governor will work on any processor with
+ * transition latency <= 10mS, using appropriate sampling
+ * rate.
+ * For CPUs with transition latency > 10mS (mostly drivers
+ * with CPUFREQ_ETERNAL), this governor will not work.
+ * All times here are in uS.
+ */
+static unsigned int def_sampling_rate;
+unsigned int suspended = 0;
+#define MIN_SAMPLING_RATE_RATIO (2)
+/* for correct statistics, we need at least 10 ticks between each measure */
+#define MIN_STAT_SAMPLING_RATE \
+ (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(CONFIG_CPU_FREQ_MIN_TICKS))
+#define MIN_SAMPLING_RATE \
+ (def_sampling_rate / MIN_SAMPLING_RATE_RATIO)
+#define MAX_SAMPLING_RATE (500 * def_sampling_rate)
+#define DEF_SAMPLING_DOWN_FACTOR (4)
+#define MAX_SAMPLING_DOWN_FACTOR (10)
+#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
+
+static void do_dbs_timer(struct work_struct *work);
+
+struct cpu_dbs_info_s {
+ struct cpufreq_policy *cur_policy;
+ unsigned int prev_cpu_idle_up;
+ unsigned int prev_cpu_idle_down;
+ unsigned int enable;
+ unsigned int down_skip;
+ unsigned int requested_freq;
+};
+static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
+
+static unsigned int dbs_enable; /* number of CPUs using this policy */
+
+/*
+ * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug
+ * lock and dbs_mutex. cpu_hotplug lock should always be held before
+ * dbs_mutex. If any function that can potentially take cpu_hotplug lock
+ * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then
+ * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock
+ * is recursive for the same process. -Venki
+ */
+static DEFINE_MUTEX (dbs_mutex);
+static DECLARE_DELAYED_WORK(dbs_work, do_dbs_timer);
+
+struct dbs_tuners {
+ unsigned int sampling_rate;
+ unsigned int sampling_down_factor;
+ unsigned int up_threshold;
+ unsigned int down_threshold;
+ unsigned int ignore_nice;
+ unsigned int freq_step_down;
+ unsigned int freq_sleep_max;
+ unsigned int freq_awake_min;
+ unsigned int freq_step_up_sleep_percent;
+};
+
+static struct dbs_tuners dbs_tuners_ins = {
+ .up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
+ .down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD,
+ .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
+ .ignore_nice = 1,
+ .freq_step_down = FREQ_STEP_DOWN,
+ .freq_sleep_max = FREQ_SLEEP_MAX,
+ .freq_awake_min = FREQ_AWAKE_MIN,
+ .freq_step_up_sleep_percent = FREQ_STEP_UP_SLEEP_PERCENT,
+};
+
+static inline unsigned int get_cpu_idle_time(unsigned int cpu)
+{
+ unsigned int add_nice = 0, ret;
+
+ if (dbs_tuners_ins.ignore_nice)
+ add_nice = kstat_cpu(cpu).cpustat.nice;
+
+ ret = kstat_cpu(cpu).cpustat.idle +
+ kstat_cpu(cpu).cpustat.iowait +
+ add_nice;
+
+ return ret;
+}
+
+/* keep track of frequency transitions */
+static int
+dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
+ void *data)
+{
+ struct cpufreq_freqs *freq = data;
+ struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info,
+ freq->cpu);
+
+ if (!this_dbs_info->enable)
+ return 0;
+
+ this_dbs_info->requested_freq = freq->new;
+
+ return 0;
+}
+
+static struct notifier_block dbs_cpufreq_notifier_block = {
+ .notifier_call = dbs_cpufreq_notifier
+};
+
+/************************** sysfs interface ************************/
+static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf)
+{
+ return sprintf (buf, "%u\n", MAX_SAMPLING_RATE);
+}
+
+static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
+{
+ return sprintf (buf, "%u\n", MIN_SAMPLING_RATE);
+}
+
+#define define_one_ro(_name) \
+static struct freq_attr _name = \
+__ATTR(_name, 0444, show_##_name, NULL)
+
+define_one_ro(sampling_rate_max);
+define_one_ro(sampling_rate_min);
+
+/* cpufreq_lagfree Governor Tunables */
+#define show_one(file_name, object) \
+static ssize_t show_##file_name \
+(struct cpufreq_policy *unused, char *buf) \
+{ \
+ return sprintf(buf, "%u\n", dbs_tuners_ins.object); \
+}
+show_one(sampling_rate, sampling_rate);
+show_one(sampling_down_factor, sampling_down_factor);
+show_one(up_threshold, up_threshold);
+show_one(down_threshold, down_threshold);
+show_one(ignore_nice_load, ignore_nice);
+show_one(freq_step_down, freq_step_down);
+show_one(freq_sleep_max, freq_sleep_max);
+show_one(freq_awake_min, freq_awake_min);
+show_one(freq_step_up_sleep_percent, freq_step_up_sleep_percent);
+
+static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+ ret = sscanf (buf, "%u", &input);
+ if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
+ return -EINVAL;
+
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.sampling_down_factor = input;
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
+static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+ ret = sscanf (buf, "%u", &input);
+
+ mutex_lock(&dbs_mutex);
+ if (ret != 1 || input > MAX_SAMPLING_RATE || input < MIN_SAMPLING_RATE) {
+ mutex_unlock(&dbs_mutex);
+ return -EINVAL;
+ }
+
+ dbs_tuners_ins.sampling_rate = input;
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
+static ssize_t store_up_threshold(struct cpufreq_policy *unused,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+ ret = sscanf (buf, "%u", &input);
+
+ mutex_lock(&dbs_mutex);
+ if (ret != 1 || input > 100 || input <= dbs_tuners_ins.down_threshold) {
+ mutex_unlock(&dbs_mutex);
+ return -EINVAL;
+ }
+
+ dbs_tuners_ins.up_threshold = input;
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
+static ssize_t store_down_threshold(struct cpufreq_policy *unused,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+ ret = sscanf (buf, "%u", &input);
+
+ mutex_lock(&dbs_mutex);
+ if (ret != 1 || input > 100 || input >= dbs_tuners_ins.up_threshold) {
+ mutex_unlock(&dbs_mutex);
+ return -EINVAL;
+ }
+
+ dbs_tuners_ins.down_threshold = input;
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
+static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+
+ unsigned int j;
+
+ ret = sscanf(buf, "%u", &input);
+ if (ret != 1)
+ return -EINVAL;
+
+ if (input > 1)
+ input = 1;
+
+ mutex_lock(&dbs_mutex);
+ if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */
+ mutex_unlock(&dbs_mutex);
+ return count;
+ }
+ dbs_tuners_ins.ignore_nice = input;
+
+ /* we need to re-evaluate prev_cpu_idle_up and prev_cpu_idle_down */
+ for_each_online_cpu(j) {
+ struct cpu_dbs_info_s *j_dbs_info;
+ j_dbs_info = &per_cpu(cpu_dbs_info, j);
+ j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(j);
+ j_dbs_info->prev_cpu_idle_down = j_dbs_info->prev_cpu_idle_up;
+ }
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
+static ssize_t store_freq_step_down(struct cpufreq_policy *unused,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+ ret = sscanf (buf, "%u", &input);
+ if (input > 100 || input < 1)
+ return -EINVAL;
+
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.freq_step_down = input;
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
+static ssize_t store_freq_step_up_sleep_percent(struct cpufreq_policy *policy,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+ ret = sscanf (buf, "%u", &input);
+ if (input > policy->cpuinfo.max_freq || input < 1)
+ return -EINVAL;
+
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.freq_step_up_sleep_percent = input;
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
+static ssize_t store_freq_sleep_max(struct cpufreq_policy *policy,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+ ret = sscanf (buf, "%u", &input);
+ if (input > policy->cpuinfo.max_freq || input < policy->cpuinfo.min_freq)
+ return -EINVAL;
+
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.freq_sleep_max = input;
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
+static ssize_t store_freq_awake_min(struct cpufreq_policy *policy,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+ ret = sscanf (buf, "%u", &input);
+ if (input > policy->cpuinfo.max_freq || input < policy->cpuinfo.min_freq)
+ return -EINVAL;
+
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.freq_awake_min = input;
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
+#define define_one_rw(_name) \
+static struct freq_attr _name = \
+__ATTR(_name, 0644, show_##_name, store_##_name)
+
+define_one_rw(sampling_rate);
+define_one_rw(sampling_down_factor);
+define_one_rw(up_threshold);
+define_one_rw(down_threshold);
+define_one_rw(ignore_nice_load);
+define_one_rw(freq_step_down);
+define_one_rw(freq_sleep_max);
+define_one_rw(freq_awake_min);
+define_one_rw(freq_step_up_sleep_percent);
+
+static struct attribute * dbs_attributes[] = {
+ &sampling_rate_max.attr,
+ &sampling_rate_min.attr,
+ &sampling_rate.attr,
+ &sampling_down_factor.attr,
+ &up_threshold.attr,
+ &down_threshold.attr,
+ &ignore_nice_load.attr,
+ &freq_step_down.attr,
+ &freq_sleep_max.attr,
+ &freq_awake_min.attr,
+ &freq_step_up_sleep_percent.attr,
+ NULL
+};
+
+static struct attribute_group dbs_attr_group = {
+ .attrs = dbs_attributes,
+ .name = "lagfree",
+};
+
+/************************** sysfs end ************************/
+
+static void dbs_check_cpu(int cpu)
+{
+ unsigned int idle_ticks, up_idle_ticks, down_idle_ticks;
+ unsigned int tmp_idle_ticks, total_idle_ticks;
+ unsigned int freq_target;
+ unsigned int freq_down_sampling_rate;
+ struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
+ struct cpufreq_policy *policy;
+
+ if (!this_dbs_info->enable)
+ return;
+
+ policy = this_dbs_info->cur_policy;
+
+ /*
+ * The default safe range is 20% to 80%
+ * Every sampling_rate, we check
+ * - If current idle time is less than 20%, then we try to
+ * increase frequency
+ * Every sampling_rate*sampling_down_factor, we check
+ * - If current idle time is more than 80%, then we try to
+ * decrease frequency
+ *
+ * Any frequency increase takes it to the maximum frequency.
+ * Frequency reduction happens at minimum steps of
+ * 5% (default) of max_frequency
+ */
+
+ /* Check for frequency increase */
+ idle_ticks = UINT_MAX;
+
+ /* Check for frequency increase */
+ total_idle_ticks = get_cpu_idle_time(cpu);
+ tmp_idle_ticks = total_idle_ticks -
+ this_dbs_info->prev_cpu_idle_up;
+ this_dbs_info->prev_cpu_idle_up = total_idle_ticks;
+
+ if (tmp_idle_ticks < idle_ticks)
+ idle_ticks = tmp_idle_ticks;
+
+ /* Scale idle ticks by 100 and compare with up and down ticks */
+ idle_ticks *= 100;
+ up_idle_ticks = (100 - dbs_tuners_ins.up_threshold) *
+ usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
+
+ if (idle_ticks < up_idle_ticks) {
+ this_dbs_info->down_skip = 0;
+ this_dbs_info->prev_cpu_idle_down =
+ this_dbs_info->prev_cpu_idle_up;
+
+ /* if we are already at full speed then break out early */
+ if (this_dbs_info->requested_freq == policy->max && !suspended)
+ return;
+
+ //freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100;
+ if (suspended)
+ freq_target = (dbs_tuners_ins.freq_step_up_sleep_percent * policy->max) / 100;
+ else
+ freq_target = policy->max;
+
+ /* max freq cannot be less than 100. But who knows.... */
+ if (unlikely(freq_target == 0))
+ freq_target = 5;
+
+ this_dbs_info->requested_freq += freq_target;
+ if (this_dbs_info->requested_freq > policy->max)
+ this_dbs_info->requested_freq = policy->max;
+
+ //Screen off mode
+ if (suspended && this_dbs_info->requested_freq > dbs_tuners_ins.freq_sleep_max)
+ this_dbs_info->requested_freq = dbs_tuners_ins.freq_sleep_max;
+
+ //Screen off mode
+ if (!suspended && this_dbs_info->requested_freq < dbs_tuners_ins.freq_awake_min)
+ this_dbs_info->requested_freq = dbs_tuners_ins.freq_awake_min;
+
+ __cpufreq_driver_target(policy, this_dbs_info->requested_freq,
+ CPUFREQ_RELATION_H);
+ return;
+ }
+
+ /* Check for frequency decrease */
+ this_dbs_info->down_skip++;
+ if (this_dbs_info->down_skip < dbs_tuners_ins.sampling_down_factor)
+ return;
+
+ /* Check for frequency decrease */
+ total_idle_ticks = this_dbs_info->prev_cpu_idle_up;
+ tmp_idle_ticks = total_idle_ticks -
+ this_dbs_info->prev_cpu_idle_down;
+ this_dbs_info->prev_cpu_idle_down = total_idle_ticks;
+
+ if (tmp_idle_ticks < idle_ticks)
+ idle_ticks = tmp_idle_ticks;
+
+ /* Scale idle ticks by 100 and compare with up and down ticks */
+ idle_ticks *= 100;
+ this_dbs_info->down_skip = 0;
+
+ freq_down_sampling_rate = dbs_tuners_ins.sampling_rate *
+ dbs_tuners_ins.sampling_down_factor;
+ down_idle_ticks = (100 - dbs_tuners_ins.down_threshold) *
+ usecs_to_jiffies(freq_down_sampling_rate);
+
+ if (idle_ticks > down_idle_ticks) {
+ /*
+ * if we are already at the lowest speed then break out early
+ * or if we 'cannot' reduce the speed as the user might want
+ * freq_target to be zero
+ */
+ if (this_dbs_info->requested_freq == policy->min && suspended
+ /*|| dbs_tuners_ins.freq_step == 0*/)
+ return;
+
+ //freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100;
+ freq_target = dbs_tuners_ins.freq_step_down; //policy->max;
+
+ /* max freq cannot be less than 100. But who knows.... */
+ if (unlikely(freq_target == 0))
+ freq_target = 5;
+
+ // prevent going under 0
+ if(freq_target > this_dbs_info->requested_freq)
+ this_dbs_info->requested_freq = policy->min;
+ else
+ this_dbs_info->requested_freq -= freq_target;
+
+ if (this_dbs_info->requested_freq < policy->min)
+ this_dbs_info->requested_freq = policy->min;
+
+ //Screen on mode
+ if (!suspended && this_dbs_info->requested_freq < dbs_tuners_ins.freq_awake_min)
+ this_dbs_info->requested_freq = dbs_tuners_ins.freq_awake_min;
+
+ //Screen off mode
+ if (suspended && this_dbs_info->requested_freq > dbs_tuners_ins.freq_sleep_max)
+ this_dbs_info->requested_freq = dbs_tuners_ins.freq_sleep_max;
+
+ __cpufreq_driver_target(policy, this_dbs_info->requested_freq,
+ CPUFREQ_RELATION_H);
+ return;
+ }
+}
+
+static void do_dbs_timer(struct work_struct *work)
+{
+ int i;
+ mutex_lock(&dbs_mutex);
+ for_each_online_cpu(i)
+ dbs_check_cpu(i);
+ schedule_delayed_work(&dbs_work,
+ usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
+ mutex_unlock(&dbs_mutex);
+}
+
+static inline void dbs_timer_init(void)
+{
+ init_timer_deferrable(&dbs_work.timer);
+ schedule_delayed_work(&dbs_work,
+ usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
+ return;
+}
+
+static inline void dbs_timer_exit(void)
+{
+ cancel_delayed_work(&dbs_work);
+ return;
+}
+
+static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
+ unsigned int event)
+{
+ unsigned int cpu = policy->cpu;
+ struct cpu_dbs_info_s *this_dbs_info;
+ unsigned int j;
+ int rc;
+
+ this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
+
+ switch (event) {
+ case CPUFREQ_GOV_START:
+ if ((!cpu_online(cpu)) || (!policy->cur))
+ return -EINVAL;
+
+ if (this_dbs_info->enable) /* Already enabled */
+ break;
+
+ mutex_lock(&dbs_mutex);
+
+ rc = sysfs_create_group(&policy->kobj, &dbs_attr_group);
+ if (rc) {
+ mutex_unlock(&dbs_mutex);
+ return rc;
+ }
+
+ for_each_cpu(j, policy->cpus) {
+ struct cpu_dbs_info_s *j_dbs_info;
+ j_dbs_info = &per_cpu(cpu_dbs_info, j);
+ j_dbs_info->cur_policy = policy;
+
+ j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(cpu);
+ j_dbs_info->prev_cpu_idle_down
+ = j_dbs_info->prev_cpu_idle_up;
+ }
+ this_dbs_info->enable = 1;
+ this_dbs_info->down_skip = 0;
+ this_dbs_info->requested_freq = policy->cur;
+
+ dbs_enable++;
+ /*
+ * Start the timerschedule work, when this governor
+ * is used for first time
+ */
+ if (dbs_enable == 1) {
+ unsigned int latency;
+ /* policy latency is in nS. Convert it to uS first */
+ latency = policy->cpuinfo.transition_latency / 1000;
+ if (latency == 0)
+ latency = 1;
+
+ def_sampling_rate = 10 * latency *
+ CONFIG_CPU_FREQ_SAMPLING_LATENCY_MULTIPLIER;
+
+ if (def_sampling_rate < MIN_STAT_SAMPLING_RATE)
+ def_sampling_rate = MIN_STAT_SAMPLING_RATE;
+
+ dbs_tuners_ins.sampling_rate = def_sampling_rate;
+
+ dbs_timer_init();
+ cpufreq_register_notifier(
+ &dbs_cpufreq_notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+ }
+
+ mutex_unlock(&dbs_mutex);
+ break;
+
+ case CPUFREQ_GOV_STOP:
+ mutex_lock(&dbs_mutex);
+ this_dbs_info->enable = 0;
+ sysfs_remove_group(&policy->kobj, &dbs_attr_group);
+ dbs_enable--;
+ /*
+ * Stop the timerschedule work, when this governor
+ * is used for first time
+ */
+ if (dbs_enable == 0) {
+ dbs_timer_exit();
+ cpufreq_unregister_notifier(
+ &dbs_cpufreq_notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+ }
+
+ mutex_unlock(&dbs_mutex);
+
+ break;
+
+ case CPUFREQ_GOV_LIMITS:
+ mutex_lock(&dbs_mutex);
+ if (policy->max < this_dbs_info->cur_policy->cur)
+ __cpufreq_driver_target(
+ this_dbs_info->cur_policy,
+ policy->max, CPUFREQ_RELATION_H);
+ else if (policy->min > this_dbs_info->cur_policy->cur)
+ __cpufreq_driver_target(
+ this_dbs_info->cur_policy,
+ policy->min, CPUFREQ_RELATION_L);
+ mutex_unlock(&dbs_mutex);
+ break;
+ }
+ return 0;
+}
+
+#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_LAGFREE
+static
+#endif
+struct cpufreq_governor cpufreq_gov_lagfree = {
+ .name = "lagfree",
+ .governor = cpufreq_governor_dbs,
+ .max_transition_latency = TRANSITION_LATENCY_LIMIT,
+ .owner = THIS_MODULE,
+};
+
+static void lagfree_early_suspend(struct early_suspend *handler) {
+ suspended = 1;
+}
+
+static void lagfree_late_resume(struct early_suspend *handler) {
+ suspended = 0;
+}
+
+static struct early_suspend lagfree_power_suspend = {
+ .suspend = lagfree_early_suspend,
+ .resume = lagfree_late_resume,
+ .level = EARLY_SUSPEND_LEVEL_DISABLE_FB + 1,
+};
+
+static int __init cpufreq_gov_dbs_init(void)
+{
+ register_early_suspend(&lagfree_power_suspend);
+ return cpufreq_register_governor(&cpufreq_gov_lagfree);
+}
+
+static void __exit cpufreq_gov_dbs_exit(void)
+{
+ /* Make sure that the scheduled work is indeed not running */
+ flush_scheduled_work();
+
+ unregister_early_suspend(&lagfree_power_suspend);
+ cpufreq_unregister_governor(&cpufreq_gov_lagfree);
+}
+
+
+MODULE_AUTHOR ("Emilio López <turl@tuxfamily.org>");
+MODULE_DESCRIPTION ("'cpufreq_lagfree' - A dynamic cpufreq governor for "
+ "Low Latency Frequency Transition capable processors "
+ "optimised for use in a battery environment"
+ "Based on conservative by Alexander Clouter");
+MODULE_LICENSE ("GPL");
+
+#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_LAGFREE
+fs_initcall(cpufreq_gov_dbs_init);
+#else
+module_init(cpufreq_gov_dbs_init);
+#endif
+module_exit(cpufreq_gov_dbs_exit);
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -441,6 +441,9 @@ extern struct cpufreq_governor cpufreq_g
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
extern struct cpufreq_governor cpufreq_gov_conservative;
#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
+#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_LAGFREE)
+extern struct cpufreq_governor cpufreq_gov_lagfree;
+#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_lagfree)
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE)
extern struct cpufreq_governor cpufreq_gov_interactive;
#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_interactive)