Add the files

1 files changed, 176 insertions, 0 deletions

diff --git a/src/detection/brightness/brightness_linux.c b/src/detection/brightness/brightness_linux.c
new file mode 100644
index 0000000..e7125f8
--- /dev/null
+++ b/src/detection/brightness/brightness_linux.c
@@ -0,0 +1,176 @@
+#include "brightness.h"
+#include "common/io.h"
+#include "common/edidHelper.h"
+#include "common/strutil.h"
+
+#include <dirent.h>
+#include <limits.h>
+
+static const char* detectWithBacklight(FFlist* result) {
+    // https://www.kernel.org/doc/Documentation/ABI/stable/sysfs-class-backlight
+    const char* backlightDirPath = "/sys/class/backlight/";
+
+    DIR* dirp = opendir(backlightDirPath);
+    if (dirp == NULL) {
+        return "Failed to open `/sys/class/backlight/`";
+    }
+
+    FF_STRBUF_AUTO_DESTROY backlightDir = ffStrbufCreateA(64);
+    ffStrbufAppendS(&backlightDir, backlightDirPath);
+
+    uint32_t backlightDirLength = backlightDir.length;
+
+    FF_STRBUF_AUTO_DESTROY buffer = ffStrbufCreate();
+
+    struct dirent* entry;
+    while ((entry = readdir(dirp)) != NULL) {
+        if (entry->d_name[0] == '.') {
+            continue;
+        }
+
+        ffStrbufAppendS(&backlightDir, entry->d_name);
+        ffStrbufAppendS(&backlightDir, "/brightness");
+        if (ffReadFileBuffer(backlightDir.chars, &buffer)) {
+            double actualBrightness = ffStrbufToDouble(&buffer, 0);
+            ffStrbufSubstrBefore(&backlightDir, backlightDirLength);
+            ffStrbufAppendS(&backlightDir, entry->d_name);
+            ffStrbufAppendS(&backlightDir, "/max_brightness");
+            if (ffReadFileBuffer(backlightDir.chars, &buffer)) {
+                FFBrightnessResult* brightness = FF_LIST_ADD(FFBrightnessResult, *result);
+                ffStrbufSubstrBeforeLastC(&backlightDir, '/');
+                ffStrbufAppendS(&backlightDir, "/device");
+                ffStrbufInitA(&brightness->name, PATH_MAX);
+                if (realpath(backlightDir.chars, brightness->name.chars)) {
+                    ffStrbufRecalculateLength(&brightness->name);
+                    // if we managed to get edid, use it
+                    ffStrbufAppendS(&brightness->name, "/edid");
+                    uint8_t edidData[128];
+                    if (ffReadFileData(brightness->name.chars, ARRAY_SIZE(edidData), edidData) == ARRAY_SIZE(edidData)) {
+                        ffStrbufClear(&brightness->name);
+                        ffEdidGetName(edidData, &brightness->name);
+                    } else {
+                        ffStrbufSubstrBeforeLastC(&brightness->name, '/'); // remove "/edid"
+                        ffStrbufSubstrAfterLastC(&brightness->name, '/');  // try getting DRM connector name
+                        if (ffCharIsDigit(brightness->name.chars[0])) {
+                            // PCI address or some unknown path, give up
+                            ffStrbufSetS(&brightness->name, entry->d_name);
+                        } else {
+                            if (ffStrbufStartsWithS(&brightness->name, "card") && ffCharIsDigit(brightness->name.chars[4])) {
+                                ffStrbufSubstrAfterFirstC(&brightness->name, '-');
+                            }
+                        }
+                    }
+                } else {
+                    ffStrbufInitS(&brightness->name, entry->d_name);
+                }
+                brightness->max = ffStrbufToDouble(&buffer, 0);
+                brightness->min = 0;
+                brightness->current = actualBrightness;
+                brightness->builtin = true;
+            }
+        }
+        ffStrbufSubstrBefore(&backlightDir, backlightDirLength);
+    }
+
+    closedir(dirp);
+
+    return NULL;
+}
+
+#ifdef FF_HAVE_DDCUTIL
+    #include "detection/displayserver/displayserver.h"
+    #include "common/library.h"
+    #include "common/mallocHelper.h"
+
+    #include <ddcutil_macros.h>
+    #include <ddcutil_c_api.h>
+
+    // Try to be compatible with ddcutil 2.0
+    #if DDCUTIL_VMAJOR >= 2
+double ddca_set_default_sleep_multiplier(double multiplier); // ddcutil 1.4
+    #else
+DDCA_Status ddca_init(const char* libopts, int syslog_level, int opts);
+    #endif
+
+static const char* detectWithDdcci(FF_A_UNUSED FFBrightnessOptions* options, FFlist* result) {
+    FF_LIBRARY_LOAD_MESSAGE(libddcutil, "libddcutil" FF_LIBRARY_EXTENSION, 5);
+    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libddcutil, ddca_get_display_info_list2)
+    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libddcutil, ddca_open_display2)
+    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libddcutil, ddca_get_any_vcp_value_using_explicit_type)
+    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libddcutil, ddca_free_any_vcp_value)
+    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libddcutil, ddca_close_display)
+
+    #ifndef FF_DISABLE_DLOPEN
+    FF_LIBRARY_LOAD_SYMBOL_LAZY(libddcutil, ddca_init)
+    if (ffddca_init) {
+        FF_SUPPRESS_IO();
+        // Ref: https://github.com/rockowitz/ddcutil/issues/344
+        if (ffddca_init(NULL, -1 /*DDCA_SYSLOG_NOT_SET*/, 1 /*DDCA_INIT_OPTIONS_DISABLE_CONFIG_FILE*/) < 0) {
+            return "ddca_init() failed";
+        }
+    } else {
+        FF_LIBRARY_LOAD_SYMBOL_LAZY(libddcutil, ddca_set_default_sleep_multiplier);
+        if (ffddca_set_default_sleep_multiplier) {
+            ffddca_set_default_sleep_multiplier(options->ddcciSleep / 40.0);
+        }
+
+        libddcutil = NULL; // Don't dlclose libddcutil. See https://github.com/rockowitz/ddcutil/issues/330
+    }
+    #else
+        #if DDCUTIL_VMAJOR >= 2
+    if (ddca_init(NULL, -1 /*DDCA_SYSLOG_NOT_SET*/, 1 /*DDCA_INIT_OPTIONS_DISABLE_CONFIG_FILE*/) < 0) {
+        return "ddca_init() failed";
+    }
+        #else
+    ddca_set_default_sleep_multiplier(options->ddcciSleep / 40.0);
+        #endif
+    #endif
+
+    FF_AUTO_FREE DDCA_Display_Info_List* infoList = NULL;
+    if (ffddca_get_display_info_list2(false, &infoList) < 0) {
+        return "ddca_get_display_info_list2(false, &infoList) failed";
+    }
+
+    if (infoList->ct == 0) {
+        return "No DDC/CI compatible displays found";
+    }
+
+    for (int index = 0; index < infoList->ct; ++index) {
+        const DDCA_Display_Info* display = &infoList->info[index];
+
+        DDCA_Display_Handle handle;
+        if (ffddca_open_display2(display->dref, false, &handle) >= 0) {
+            DDCA_Any_Vcp_Value* vcpValue = NULL;
+            if (ffddca_get_any_vcp_value_using_explicit_type(handle, 0x10 /*brightness*/, DDCA_NON_TABLE_VCP_VALUE, &vcpValue) >= 0) {
+                assert(vcpValue->value_type == DDCA_NON_TABLE_VCP_VALUE);
+                int current = VALREC_CUR_VAL(vcpValue), max = VALREC_MAX_VAL(vcpValue);
+                ffddca_free_any_vcp_value(vcpValue);
+
+                FFBrightnessResult* brightness = FF_LIST_ADD(FFBrightnessResult, *result);
+                brightness->max = max;
+                brightness->min = 0;
+                brightness->current = current;
+                ffStrbufInitS(&brightness->name, display->model_name);
+            }
+            ffddca_close_display(handle);
+        }
+    }
+
+    return NULL;
+}
+#endif
+
+const char* ffDetectBrightness(FF_A_UNUSED FFBrightnessOptions* options, FFlist* result) {
+    detectWithBacklight(result);
+
+#ifdef FF_HAVE_DDCUTIL
+    if (options->ddcciSleep != FF_BRIGHTNESS_DDCCI_SLEEP_SKIP) {
+        const FFDisplayServerResult* displayServer = ffConnectDisplayServer();
+        if (result->length < displayServer->displays.length) {
+            detectWithDdcci(options, result);
+        }
+    }
+#endif
+
+    return NULL;
+}