[PATCH v5 5/7] PM / devfreq: Show the all available frequencies

Chanwoo Choi
2017-10-23T01:32:21Z

The commit a76caf55e5b35 ("thermal: Add devfreq cooling") allows
the devfreq device to use the cooling device. When the cooling down
are required, the devfreq_cooling.c disables the OPP entry with
the dev_pm_opp_disable(). In result, 'available_frequencies'[1]
sysfs node never came to show the all available frequencies.
[1] /sys/class/devfreq/.../available_frequencies

So, this patch uses the 'freq_table' in the 'struct devfreq_dev_profile'
in order to show the all available frequencies.
- If 'freq_table' is NULL, devfreq core initializes them by using OPP values.
- If 'freq_table' is initialized, devfreq core just uses the 'freq_table'.

And this patch adds some comment about the sort way of 'freq_table'.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
---
drivers/devfreq/devfreq.c | 16 +++++-----------
include/linux/devfreq.h | 5 +++--
2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index b2920cd2b78e..381f92e5e794 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -1194,22 +1194,16 @@ static ssize_t available_frequencies_show(struct device *d,
char *buf)
{
struct devfreq *df = to_devfreq(d);
- struct device *dev = df->dev.parent;
- struct dev_pm_opp *opp;
ssize_t count = 0;
- unsigned long freq = 0;
+ int i;

- do {
- opp = dev_pm_opp_find_freq_ceil(dev, &freq);
- if (IS_ERR(opp))
- break;
+ mutex_lock(&df->lock);

- dev_pm_opp_put(opp);
+ for (i = 0; i < df->profile->max_state; i++)
count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
- "%lu ", freq);
- freq++;
- } while (1);
+ "%lu ", df->profile->freq_table[i]);

+ mutex_unlock(&df->lock);
/* Truncate the trailing space */
if (count)
count--;
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 997a9eb34191..19520625ea94 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -84,8 +84,9 @@ struct devfreq_dev_status {
* from devfreq_remove_device() call. If the user
* has registered devfreq->nb at a notifier-head,
* this is the time to unregister it.
- * @freq_table: Optional list of frequencies to support statistics.
- * @max_state: The size of freq_table.
+ * @freq_table: Optional list of frequencies to support statistics
+ * and freq_table must be generated in ascending order.
+ * @max_state: The size of freq_table.
*/
struct devfreq_dev_profile {
unsigned long initial_freq;
--
1.9.1