PM / devfreq: Use the available min/max frequency

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>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

1 files changed, 32 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 @@ unlock:
 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 DEVICE_ATTR_RW(min_freq);
 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);