[PATCH v3 4/8] PM / devfreq: Show the all available frequencies

[Chanwoo Choi]

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.c...@samsung.com>
---
 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