[PATCH v5 3/7] PM / devfreq: Use the available min/max frequency

Chanwoo Choi
2017-10-23T01:35:14Z

The commit a76caf55e5b35 ("thermal: Add devfreq cooling") is able
to disable OPP as a cooling device. In result, both update_devfreq()
and {min|max}_freq_show() have to consider the 'opp->available'
status of each OPP.

So, this patch adds the 'scaling_{min|max}_freq' to struct devfreq
in order to indicate the available mininum and maximum frequency
by adjusting OPP interface such as dev_pm_opp_{disable|enable}().
The 'scaling_{min|max}_freq' are used for on both update_devfreq()
and {min|max}_freq_show().

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
drivers/devfreq/devfreq.c | 40 ++++++++++++++++++++++++++++++++--------
include/linux/devfreq.h | 4 ++++
2 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index b6ba24e5db0d..ee3e7cee30b6 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -28,6 +28,9 @@
#include <linux/of.h>
#include "governor.h"

+#define MAX(a,b) ((a > b) ? a : b)
+#define MIN(a,b) ((a < b) ? a : b)
+
static struct class *devfreq_class;

/*
@@ -255,7 +258,7 @@ static int devfreq_notify_transition(struct devfreq *devfreq,
int update_devfreq(struct devfreq *devfreq)
{
struct devfreq_freqs freqs;
- unsigned long freq, cur_freq;
+ unsigned long freq, cur_freq, min_freq, max_freq;
int err = 0;
u32 flags = 0;

@@ -273,19 +276,21 @@ int update_devfreq(struct devfreq *devfreq)
return err;

/*
- * Adjust the frequency with user freq and QoS.
+ * Adjust the frequency with user freq, QoS and available freq.
*
* List from the highest priority
* max_freq
* min_freq
*/
+ max_freq = MIN(devfreq->scaling_max_freq, devfreq->max_freq);
+ min_freq = MAX(devfreq->scaling_min_freq, devfreq->min_freq);

- if (devfreq->min_freq && freq < devfreq->min_freq) {
- freq = devfreq->min_freq;
+ if (min_freq && freq < min_freq) {
+ freq = min_freq;
flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
}
- if (devfreq->max_freq && freq > devfreq->max_freq) {
- freq = devfreq->max_freq;
+ if (max_freq && freq > max_freq) {
+ freq = max_freq;
flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
}

@@ -494,6 +499,19 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
int ret;

mutex_lock(&devfreq->lock);
+
+ devfreq->scaling_min_freq = find_available_min_freq(devfreq);
+ if (!devfreq->scaling_min_freq) {
+ mutex_unlock(&devfreq->lock);
+ return -EINVAL;
+ }
+
+ devfreq->scaling_max_freq = find_available_max_freq(devfreq);
+ if (!devfreq->scaling_max_freq) {
+ mutex_unlock(&devfreq->lock);
+ return -EINVAL;
+ }
+
ret = update_devfreq(devfreq);
mutex_unlock(&devfreq->lock);

@@ -593,6 +611,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
err = -EINVAL;
goto err_dev;
}
+ devfreq->scaling_min_freq = devfreq->min_freq;

devfreq->max_freq = find_available_max_freq(devfreq);
if (!devfreq->max_freq) {
@@ -600,6 +619,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
err = -EINVAL;
goto err_dev;
}
+ devfreq->scaling_max_freq = devfreq->max_freq;

dev_set_name(&devfreq->dev, "devfreq%d",
atomic_inc_return(&devfreq_no));
@@ -1127,7 +1147,9 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
- return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq);
+ struct devfreq *df = to_devfreq(dev);
+
+ return sprintf(buf, "%lu\n", MAX(df->scaling_min_freq, df->min_freq));
}

static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
@@ -1161,7 +1183,9 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
- return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq);
+ struct devfreq *df = to_devfreq(dev);
+
+ return sprintf(buf, "%lu\n", MIN(df->scaling_max_freq, df->max_freq));
}
static DEVICE_ATTR_RW(max_freq);

diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 597294e0cc40..997a9eb34191 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -120,6 +120,8 @@ struct devfreq_dev_profile {
* touch this.
* @min_freq: Limit minimum frequency requested by user (0: none)
* @max_freq: Limit maximum frequency requested by user (0: none)
+ * @scaling_min_freq: Limit minimum frequency requested by OPP interface
+ * @scaling_max_freq: Limit maximum frequency requested by OPP interface
* @stop_polling: devfreq polling status of a device.
* @total_trans: Number of devfreq transitions
* @trans_table: Statistics of devfreq transitions
@@ -153,6 +155,8 @@ struct devfreq {

unsigned long min_freq;
unsigned long max_freq;
+ unsigned long scaling_min_freq;
+ unsigned long scaling_max_freq;
bool stop_polling;

/* information for device frequency transition */
--
1.9.1