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path: root/drivers/devfreq/devfreq.c
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Diffstat (limited to 'drivers/devfreq/devfreq.c')
-rw-r--r--drivers/devfreq/devfreq.c118
1 files changed, 88 insertions, 30 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 4c49bb1330b5..141413067b5c 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -11,6 +11,7 @@
*/
#include <linux/kernel.h>
+#include <linux/kmod.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/err.h>
@@ -28,9 +29,6 @@
#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;
/*
@@ -221,6 +219,49 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
return ERR_PTR(-ENODEV);
}
+/**
+ * try_then_request_governor() - Try to find the governor and request the
+ * module if is not found.
+ * @name: name of the governor
+ *
+ * Search the list of devfreq governors and request the module and try again
+ * if is not found. This can happen when both drivers (the governor driver
+ * and the driver that call devfreq_add_device) are built as modules.
+ * devfreq_list_lock should be held by the caller. Returns the matched
+ * governor's pointer.
+ */
+static struct devfreq_governor *try_then_request_governor(const char *name)
+{
+ struct devfreq_governor *governor;
+ int err = 0;
+
+ if (IS_ERR_OR_NULL(name)) {
+ pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
+ return ERR_PTR(-EINVAL);
+ }
+ WARN(!mutex_is_locked(&devfreq_list_lock),
+ "devfreq_list_lock must be locked.");
+
+ governor = find_devfreq_governor(name);
+ if (IS_ERR(governor)) {
+ mutex_unlock(&devfreq_list_lock);
+
+ if (!strncmp(name, DEVFREQ_GOV_SIMPLE_ONDEMAND,
+ DEVFREQ_NAME_LEN))
+ err = request_module("governor_%s", "simpleondemand");
+ else
+ err = request_module("governor_%s", name);
+ /* Restore previous state before return */
+ mutex_lock(&devfreq_list_lock);
+ if (err)
+ return NULL;
+
+ governor = find_devfreq_governor(name);
+ }
+
+ return governor;
+}
+
static int devfreq_notify_transition(struct devfreq *devfreq,
struct devfreq_freqs *freqs, unsigned int state)
{
@@ -280,14 +321,14 @@ int update_devfreq(struct devfreq *devfreq)
* max_freq
* min_freq
*/
- max_freq = MIN(devfreq->scaling_max_freq, devfreq->max_freq);
- min_freq = MAX(devfreq->scaling_min_freq, devfreq->min_freq);
+ max_freq = min(devfreq->scaling_max_freq, devfreq->max_freq);
+ min_freq = max(devfreq->scaling_min_freq, devfreq->min_freq);
- if (min_freq && freq < min_freq) {
+ if (freq < min_freq) {
freq = min_freq;
flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
}
- if (max_freq && freq > max_freq) {
+ if (freq > max_freq) {
freq = max_freq;
flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
}
@@ -534,10 +575,6 @@ static void devfreq_dev_release(struct device *dev)
list_del(&devfreq->node);
mutex_unlock(&devfreq_list_lock);
- if (devfreq->governor)
- devfreq->governor->event_handler(devfreq,
- DEVFREQ_GOV_STOP, NULL);
-
if (devfreq->profile->exit)
devfreq->profile->exit(devfreq->dev.parent);
@@ -646,9 +683,8 @@ struct devfreq *devfreq_add_device(struct device *dev,
mutex_unlock(&devfreq->lock);
mutex_lock(&devfreq_list_lock);
- list_add(&devfreq->node, &devfreq_list);
- governor = find_devfreq_governor(devfreq->governor_name);
+ governor = try_then_request_governor(devfreq->governor_name);
if (IS_ERR(governor)) {
dev_err(dev, "%s: Unable to find governor for the device\n",
__func__);
@@ -664,19 +700,20 @@ struct devfreq *devfreq_add_device(struct device *dev,
__func__);
goto err_init;
}
+
+ list_add(&devfreq->node, &devfreq_list);
+
mutex_unlock(&devfreq_list_lock);
return devfreq;
err_init:
- list_del(&devfreq->node);
mutex_unlock(&devfreq_list_lock);
- device_unregister(&devfreq->dev);
+ devfreq_remove_device(devfreq);
devfreq = NULL;
err_dev:
- if (devfreq)
- kfree(devfreq);
+ kfree(devfreq);
err_out:
return ERR_PTR(err);
}
@@ -693,6 +730,9 @@ int devfreq_remove_device(struct devfreq *devfreq)
if (!devfreq)
return -EINVAL;
+ if (devfreq->governor)
+ devfreq->governor->event_handler(devfreq,
+ DEVFREQ_GOV_STOP, NULL);
device_unregister(&devfreq->dev);
return 0;
@@ -991,7 +1031,7 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
return -EINVAL;
mutex_lock(&devfreq_list_lock);
- governor = find_devfreq_governor(str_governor);
+ governor = try_then_request_governor(str_governor);
if (IS_ERR(governor)) {
ret = PTR_ERR(governor);
goto out;
@@ -1126,17 +1166,26 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
struct devfreq *df = to_devfreq(dev);
unsigned long value;
int ret;
- unsigned long max;
ret = sscanf(buf, "%lu", &value);
if (ret != 1)
return -EINVAL;
mutex_lock(&df->lock);
- max = df->max_freq;
- if (value && max && value > max) {
- ret = -EINVAL;
- goto unlock;
+
+ if (value) {
+ if (value > df->max_freq) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+ } else {
+ unsigned long *freq_table = df->profile->freq_table;
+
+ /* Get minimum frequency according to sorting order */
+ if (freq_table[0] < freq_table[df->profile->max_state - 1])
+ value = freq_table[0];
+ else
+ value = freq_table[df->profile->max_state - 1];
}
df->min_freq = value;
@@ -1152,7 +1201,7 @@ static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
{
struct devfreq *df = to_devfreq(dev);
- return sprintf(buf, "%lu\n", MAX(df->scaling_min_freq, df->min_freq));
+ 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,
@@ -1161,17 +1210,26 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
struct devfreq *df = to_devfreq(dev);
unsigned long value;
int ret;
- unsigned long min;
ret = sscanf(buf, "%lu", &value);
if (ret != 1)
return -EINVAL;
mutex_lock(&df->lock);
- min = df->min_freq;
- if (value && min && value < min) {
- ret = -EINVAL;
- goto unlock;
+
+ if (value) {
+ if (value < df->min_freq) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+ } else {
+ unsigned long *freq_table = df->profile->freq_table;
+
+ /* Get maximum frequency according to sorting order */
+ if (freq_table[0] < freq_table[df->profile->max_state - 1])
+ value = freq_table[df->profile->max_state - 1];
+ else
+ value = freq_table[0];
}
df->max_freq = value;
@@ -1188,7 +1246,7 @@ static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
{
struct devfreq *df = to_devfreq(dev);
- return sprintf(buf, "%lu\n", MIN(df->scaling_max_freq, df->max_freq));
+ return sprintf(buf, "%lu\n", min(df->scaling_max_freq, df->max_freq));
}
static DEVICE_ATTR_RW(max_freq);
generated by cgit v1.2.3 (git 2.46.0) at 2025-11-04 01:22:04 +0000