cpufreq: Introduce new relation for freq selection

Introduce CPUFREQ_RELATION_C for frequency selection.
It selects the frequency with the minimum euclidean distance to target.
In case of equal distance between 2 frequencies, it will select the
greater frequency.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/cpufreq/freq_table.c b/drivers/cpufreq/freq_table.c
index 1632981c4b25..df14766a8e06 100644
--- a/drivers/cpufreq/freq_table.c
+++ b/drivers/cpufreq/freq_table.c
@@ -117,7 +117,7 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
                 .frequency = 0,
         };
         struct cpufreq_frequency_table *pos;
-        unsigned int freq, i = 0;
+        unsigned int freq, diff, i = 0;
 
         pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
                                         target_freq, relation, policy->cpu);
@@ -127,6 +127,7 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
                 suboptimal.frequency = ~0;
                 break;
         case CPUFREQ_RELATION_L:
+        case CPUFREQ_RELATION_C:
                 optimal.frequency = ~0;
                 break;
         }
@@ -168,6 +169,15 @@ int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
                                 }
                         }
                         break;
+                case CPUFREQ_RELATION_C:
+                        diff = abs(freq - target_freq);
+                        if (diff < optimal.frequency ||
+                            (diff == optimal.frequency &&
+                             freq > table[optimal.driver_data].frequency)) {
+                                optimal.frequency = diff;
+                                optimal.driver_data = i;
+                        }
+                        break;
                 }
         }
         if (optimal.driver_data > i) {