iBasso DX50/DX90: CPU info enhancements.

System -> Debug (Keep Out) -> View CPU stats

Will now show the current cpufreq scaling governor, minimum, current and
maximum cpufreq scaling frequency for each CPU.

This may be genric for Android kernel based devices but is only enabled
for iBasso Devices. Other maintainers may choose do adopt this.

Change-Id: I53e212f8707bf2abaa557e297293fb559ac37058

apps/debug_menu.c

@@ -244,6 +244,23 @@ static const char* get_cpuinfo(int selected_item, void *data,
         {
             int cpu = (selected_item - 5) / (state_count + 1);
             int cpu_line = (selected_item - 5) % (state_count + 1);
+#if defined(DX50) || defined(DX90)
+            int min_freq = min_scaling_frequency(cpu);
+            int cur_freq = current_scaling_frequency(cpu);
+            int max_freq = max_scaling_frequency(cpu);
+            char governor[20];
+            bool have_governor = current_scaling_governor(cpu, governor, sizeof(governor));
+            if(cpu_line == 0)
+            {
+                sprintf(buffer,
+                        " CPU%d: %s: %d/%d/%d MHz",
+                        cpu,
+                        have_governor ? governor : "Min/Cur/Max freq",
+                        min_freq > 0 ? min_freq/1000 : -1,
+                        cur_freq > 0 ? cur_freq/1000 : -1,
+                        max_freq > 0 ? max_freq/1000 : -1);
+            }
+#else
             int freq1 = frequency_linux(cpu, false);
             int freq2 = frequency_linux(cpu, true);
             if (cpu_line == 0)
@@ -252,6 +269,7 @@ static const char* get_cpuinfo(int selected_item, void *data,
                                 freq1 > 0 ? freq1/1000 : -1,
                                 freq2 > 0 ? freq2/1000 : -1);
             }
+#endif
             else
             {
                 cpustatetimes_linux(cpu, states, ARRAYLEN(states));

firmware/target/hosted/cpuinfo-linux.c

@@ -35,8 +35,14 @@
 #include "cpuinfo-linux.h"
 #include "gcc_extensions.h"
 
+#if defined(DX50) || defined(DX90)
+#include <limits.h>
+#include <string.h>
+#include "debug.h"
+#endif
+
 #undef open /* want the *real* open here, not sim_open or the like */
-#if (CONFIG_PLATFORM & PLATFORM_ANDROID)
+#if (CONFIG_PLATFORM & PLATFORM_ANDROID) || defined(DX50) || defined(DX90)
 #include "cpu-features.h"
 #define get_nprocs android_getCpuCount
 #endif
@@ -154,6 +160,132 @@ int frequency_linux(int cpu, bool scaling)
     return ret;
 }
 
+#if defined(DX50) || defined(DX90)
+bool current_scaling_governor(int cpu, char* governor, int governor_size)
+{
+    if((cpu < 0) || (governor == NULL) || (governor_size <= 0))
+    {
+        return false;
+    }
+
+    char path[PATH_MAX];
+    snprintf(path,
+             sizeof(path),
+             "/sys/devices/system/cpu/cpu%d/cpufreq/scaling_governor",
+             cpu);
+    FILE *f = fopen(path, "r");
+    if(f == NULL)
+    {
+        DEBUGF("ERROR %s: Can not open %s for reading.", __func__, path);
+        return false;
+    }
+
+    if(fgets(governor, governor_size, f) == NULL)
+    {
+        DEBUGF("ERROR %s: Read failed for %s.", __func__, path);
+        fclose(f);
+        return false;
+    }
+
+    if(strlen(governor) > 0)
+    {
+        governor[strlen(governor) - 1] = '\0';
+    }
+
+    fclose(f);
+    return true;
+}
+
+
+enum cpu_frequency_options
+{
+    SCALING_MIN_FREQ = 0,
+    SCALING_CUR_FREQ,
+    SCALING_MAX_FREQ
+};
+
+
+static int read_cpu_frequency(int cpu, enum cpu_frequency_options freqOpt)
+{
+    if(cpu < 0)
+    {
+        return -1;
+    }
+
+    char path[PATH_MAX];
+    switch(freqOpt)
+    {
+        case SCALING_MIN_FREQ:
+        {
+            snprintf(path,
+                     PATH_MAX,
+                     "/sys/devices/system/cpu/cpu%d/cpufreq/scaling_min_freq",
+                     cpu);
+            break;
+        }
+
+        case SCALING_CUR_FREQ:
+        {
+            snprintf(path,
+                     PATH_MAX,
+                     "/sys/devices/system/cpu/cpu%d/cpufreq/scaling_cur_freq",
+                     cpu);
+            break;
+        }
+
+        case SCALING_MAX_FREQ:
+        {
+            snprintf(path,
+                     PATH_MAX,
+                     "/sys/devices/system/cpu/cpu%d/cpufreq/scaling_max_freq",
+                     cpu);
+            break;
+        }
+
+        default:
+        {
+            DEBUGF("ERROR %s: Unknown CpuFrequencyOptions: %d.", __func__, freqOpt);
+            return -1;
+        }
+    }
+
+    FILE *f = fopen(path, "r");
+    if(f == NULL)
+    {
+        DEBUGF("ERROR %s: Can not open %s for reading.", __func__, path);
+        return -1;
+    }
+
+    int freq;
+    if(fscanf(f, "%d", &freq) == EOF)
+    {
+        DEBUGF("ERROR %s: Read failed for %s.", __func__, path);
+        freq = -1;
+    }
+
+    fclose(f);
+    return(freq);
+}
+
+
+int min_scaling_frequency(int cpu)
+{
+    return(read_cpu_frequency(cpu, SCALING_MIN_FREQ));
+}
+
+
+int current_scaling_frequency(int cpu)
+{
+    return(read_cpu_frequency(cpu, SCALING_CUR_FREQ));
+}
+
+
+int max_scaling_frequency(int cpu)
+{
+    return(read_cpu_frequency(cpu, SCALING_MAX_FREQ));
+}
+#endif
+
 int cpustatetimes_linux(int cpu, struct time_state* data, int max_elements)
 {
     int elements_left = max_elements, cpu_dev;

firmware/target/hosted/cpuinfo-linux.h

@@ -40,6 +40,28 @@ struct time_state {
 
 int cpuusage_linux(struct cpuusage* u);
 int frequency_linux(int cpu, bool scaling);
+
+#if defined(DX50) || defined(DX90)
+/*
+    Get the current cpufreq scaling governor.
+    cpu [in]: The number of the cpu to query.
+    governor [out]: Buffer for the governor.
+    governor_size [in]: Size of the buffer for the governor.
+    Returns true on success, false else.
+*/
+bool current_scaling_governor(int cpu, char* governor, int governor_size);
+
+
+/*
+    Get the minimum, current or maximum cpufreq scaling frequency.
+    cpu [in]: The number of the cpu to query.
+    Returns -1 failure.
+*/
+int min_scaling_frequency(int cpu);
+int current_scaling_frequency(int cpu);
+int max_scaling_frequency(int cpu);
+#endif
+
 int cpustatetimes_linux(int cpu, struct time_state* data, int max_elements);
 int cpucount_linux(void);