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authorLeonard Crestez <leonard.crestez@nxp.com>2019-12-05 12:05:06 +0200
committerChanwoo Choi <cw00.choi@samsung.com>2019-12-09 12:19:16 +0900
commit05d7ae15cfb18f9ce55eef85bb6bcd62d31acc57 (patch)
tree55a49a01c747e80705aaf3b4875f72c7246a17e8 /drivers/devfreq/devfreq.c
parent42a6b25e67df6ee6675e8d1eaf18065bd73328ba (diff)
downloadlinux-05d7ae15cfb18f9ce55eef85bb6bcd62d31acc57.tar.bz2
PM / devfreq: Add PM QoS support
Register notifiers with the PM QoS framework in order to respond to requests for DEV_PM_QOS_MIN_FREQUENCY and DEV_PM_QOS_MAX_FREQUENCY. No notifiers are added by this patch but PM QoS constraints can be imposed externally (for example from other devices). Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Acked-by: Chanwoo Choi <cw00.choi@samsung.com> Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Tested-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Diffstat (limited to 'drivers/devfreq/devfreq.c')
-rw-r--r--drivers/devfreq/devfreq.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 59f9fa8b54d1..f6e272085448 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -24,11 +24,14 @@
#include <linux/printk.h>
#include <linux/hrtimer.h>
#include <linux/of.h>
+#include <linux/pm_qos.h>
#include "governor.h"
#define CREATE_TRACE_POINTS
#include <trace/events/devfreq.h>
+#define HZ_PER_KHZ 1000
+
static struct class *devfreq_class;
/*
@@ -111,6 +114,7 @@ static void get_freq_range(struct devfreq *devfreq,
unsigned long *max_freq)
{
unsigned long *freq_table = devfreq->profile->freq_table;
+ s32 qos_min_freq, qos_max_freq;
lockdep_assert_held(&devfreq->lock);
@@ -127,6 +131,16 @@ static void get_freq_range(struct devfreq *devfreq,
*max_freq = freq_table[0];
}
+ /* Apply constraints from PM QoS */
+ qos_min_freq = dev_pm_qos_read_value(devfreq->dev.parent,
+ DEV_PM_QOS_MIN_FREQUENCY);
+ qos_max_freq = dev_pm_qos_read_value(devfreq->dev.parent,
+ DEV_PM_QOS_MAX_FREQUENCY);
+ *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq);
+ if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE)
+ *max_freq = min(*max_freq,
+ (unsigned long)HZ_PER_KHZ * qos_max_freq);
+
/* Apply constraints from sysfs */
*min_freq = max(*min_freq, devfreq->min_freq);
*max_freq = min(*max_freq, devfreq->max_freq);
@@ -627,6 +641,45 @@ out:
}
/**
+ * qos_notifier_call() - Common handler for QoS constraints.
+ * @devfreq: the devfreq instance.
+ */
+static int qos_notifier_call(struct devfreq *devfreq)
+{
+ int err;
+
+ mutex_lock(&devfreq->lock);
+ err = update_devfreq(devfreq);
+ mutex_unlock(&devfreq->lock);
+ if (err)
+ dev_err(devfreq->dev.parent,
+ "failed to update frequency from PM QoS (%d)\n",
+ err);
+
+ return NOTIFY_OK;
+}
+
+/**
+ * qos_min_notifier_call() - Callback for QoS min_freq changes.
+ * @nb: Should be devfreq->nb_min
+ */
+static int qos_min_notifier_call(struct notifier_block *nb,
+ unsigned long val, void *ptr)
+{
+ return qos_notifier_call(container_of(nb, struct devfreq, nb_min));
+}
+
+/**
+ * qos_max_notifier_call() - Callback for QoS max_freq changes.
+ * @nb: Should be devfreq->nb_max
+ */
+static int qos_max_notifier_call(struct notifier_block *nb,
+ unsigned long val, void *ptr)
+{
+ return qos_notifier_call(container_of(nb, struct devfreq, nb_max));
+}
+
+/**
* devfreq_dev_release() - Callback for struct device to release the device.
* @dev: the devfreq device
*
@@ -635,11 +688,23 @@ out:
static void devfreq_dev_release(struct device *dev)
{
struct devfreq *devfreq = to_devfreq(dev);
+ int err;
mutex_lock(&devfreq_list_lock);
list_del(&devfreq->node);
mutex_unlock(&devfreq_list_lock);
+ err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max,
+ DEV_PM_QOS_MAX_FREQUENCY);
+ if (err && err != -ENOENT)
+ dev_warn(dev->parent,
+ "Failed to remove max_freq notifier: %d\n", err);
+ err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min,
+ DEV_PM_QOS_MIN_FREQUENCY);
+ if (err && err != -ENOENT)
+ dev_warn(dev->parent,
+ "Failed to remove min_freq notifier: %d\n", err);
+
if (devfreq->profile->exit)
devfreq->profile->exit(devfreq->dev.parent);
@@ -762,6 +827,18 @@ struct devfreq *devfreq_add_device(struct device *dev,
mutex_unlock(&devfreq->lock);
+ devfreq->nb_min.notifier_call = qos_min_notifier_call;
+ err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_min,
+ DEV_PM_QOS_MIN_FREQUENCY);
+ if (err)
+ goto err_devfreq;
+
+ devfreq->nb_max.notifier_call = qos_max_notifier_call;
+ err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_max,
+ DEV_PM_QOS_MAX_FREQUENCY);
+ if (err)
+ goto err_devfreq;
+
mutex_lock(&devfreq_list_lock);
governor = try_then_request_governor(devfreq->governor_name);