[PATCH v2 4/8] PM / devfreq: Show the all available frequencies

From: Chanwoo Choi
Date: Wed Sep 20 2017 - 20:34:16 EST


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'.

Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
---
drivers/devfreq/devfreq.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 799a0cf75d39..1c4b377cacfb 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -1185,22 +1185,26 @@ 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;
+ unsigned long *freq_table;
+ int i, max_state;

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

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

+ if (freq_table[0] < freq_table[max_state - 1]) {
+ for (i = 0; i < max_state; i++)
+ count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
+ "%lu ", freq_table[i]);
+ } else {
+ for (i = max_state - 1; i >= 0 ; i--)
+ count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
+ "%lu ", freq_table[i]);
+ }
+
+ mutex_unlock(&df->lock);
/* Truncate the trailing space */
if (count)
count--;
--
1.9.1