PM / devfreq: Set the freq_table of devfreq device

This patch initialize the freq_table array of each devfreq device by using
the devfreq_set_freq_table(). If freq_table is NULL, the devfreq framework
is not able to support the frequency transtion information through sysfs.

The OPP core uses the integer type for the number of opps in the opp list
and uses the 'unsigned long' type for each frequency. So, this patch
modifies the type of some variable as following:
- the type of freq_table : unsigned int -> unsigned long
- the type of max_state  : unsigned int -> int

- Corrected types, format strings, mutex usages by MyungJoo

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

drivers/devfreq/devfreq.c

@@ -84,6 +84,46 @@ static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
 	return -EINVAL;
 }
 
+/**
+ * devfreq_set_freq_table() - Initialize freq_table for the frequency
+ * @devfreq:	the devfreq instance
+ */
+static void devfreq_set_freq_table(struct devfreq *devfreq)
+{
+	struct devfreq_dev_profile *profile = devfreq->profile;
+	struct dev_pm_opp *opp;
+	unsigned long freq;
+	int i, count;
+
+	/* Initialize the freq_table from OPP table */
+	count = dev_pm_opp_get_opp_count(devfreq->dev.parent);
+	if (count <= 0)
+		return;
+
+	profile->max_state = count;
+	profile->freq_table = devm_kcalloc(devfreq->dev.parent,
+					profile->max_state,
+					sizeof(*profile->freq_table),
+					GFP_KERNEL);
+	if (!profile->freq_table) {
+		profile->max_state = 0;
+		return;
+	}
+
+	rcu_read_lock();
+	for (i = 0, freq = 0; i < profile->max_state; i++, freq++) {
+		opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq);
+		if (IS_ERR(opp)) {
+			devm_kfree(devfreq->dev.parent, profile->freq_table);
+			profile->max_state = 0;
+			rcu_read_unlock();
+			return;
+		}
+		profile->freq_table[i] = freq;
+	}
+	rcu_read_unlock();
+}
+
 /**
  * devfreq_update_status() - Update statistics of devfreq behavior
  * @devfreq:	the devfreq instance
@@ -478,6 +518,12 @@ struct devfreq *devfreq_add_device(struct device *dev,
 	devfreq->data = data;
 	devfreq->nb.notifier_call = devfreq_notifier_call;
 
+	if (!devfreq->profile->max_state && !devfreq->profile->freq_table) {
+		mutex_unlock(&devfreq->lock);
+		devfreq_set_freq_table(devfreq);
+		mutex_lock(&devfreq->lock);
+	}
+
 	devfreq->trans_table =	devm_kzalloc(dev, sizeof(unsigned int) *
 						devfreq->profile->max_state *
 						devfreq->profile->max_state,
@@ -1007,7 +1053,7 @@ static ssize_t trans_stat_show(struct device *dev,
 	len = sprintf(buf, "   From  :   To\n");
 	len += sprintf(buf + len, "         :");
 	for (i = 0; i < max_state; i++)
-		len += sprintf(buf + len, "%8u",
+		len += sprintf(buf + len, "%8lu",
 				devfreq->profile->freq_table[i]);
 
 	len += sprintf(buf + len, "   time(ms)\n");
@@ -1019,7 +1065,7 @@ static ssize_t trans_stat_show(struct device *dev,
 		} else {
 			len += sprintf(buf + len, " ");
 		}
-		len += sprintf(buf + len, "%8u:",
+		len += sprintf(buf + len, "%8lu:",
 				devfreq->profile->freq_table[i]);
 		for (j = 0; j < max_state; j++)
 			len += sprintf(buf + len, "%8u",

include/linux/devfreq.h

@@ -89,7 +89,7 @@ struct devfreq_dev_profile {
 	int (*get_cur_freq)(struct device *dev, unsigned long *freq);
 	void (*exit)(struct device *dev);
 
-	unsigned int *freq_table;
+	unsigned long *freq_table;
 	unsigned int max_state;
 };