Add wrappers for brightness-related functions (#246)

* Add wrappers for brightness-related functions

nx/include/switch/services/lbl.h

@@ -1,7 +1,7 @@
 /**
  * @file lbl.h
  * @brief LBL service IPC wrapper.
- * @author SciresM
+ * @author SciresM, exelix
  * @copyright libnx Authors
  */
 #pragma once
@@ -12,3 +12,13 @@ void lblExit(void);
 
 Result lblSwitchBacklightOn(u64 fade_time);
 Result lblSwitchBacklightOff(u64 fade_time);
+
+/**
+ * @note The brightness goes from 0 to 1.0.
+ */
+Result lblSetCurrentBrightnessSetting(float brightness);
+Result lblGetCurrentBrightnessSetting(float *out_value);
+
+Result lblEnableAutoBrightnessControl(void);
+Result lblDisableAutoBrightnessControl(void);
+Result lblIsAutoBrightnessControlEnabled(bool *out_value);

nx/source/services/lbl.c

@@ -29,7 +29,39 @@ void lblExit(void) {
     }
 }
 
-static Result _lblSwitchBacklight(u32 cmd_id, u64 fade_time) {
+static Result _lblCmdNoIO(u64 cmd_id) {
+    IpcCommand c;
+    ipcInitialize(&c);
+
+    struct {
+        u64 magic;
+        u64 cmd_id;
+    } *raw;
+
+    raw = serviceIpcPrepareHeader(&g_lblSrv, &c, sizeof(*raw));
+
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = cmd_id;
+
+    Result rc = serviceIpcDispatch(&g_lblSrv);
+
+    if (R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        struct {
+            u64 magic;
+            u64 result;
+        } *resp;
+
+        serviceIpcParse(&g_lblSrv, &r, sizeof(*resp));
+        resp = r.Raw;
+
+        rc = resp->result;
+    }
+
+    return rc;
+}
+
+static Result _lblSwitchBacklight(u64 cmd_id, u64 fade_time) {
     IpcCommand c;
     ipcInitialize(&c);
 
@@ -70,3 +102,115 @@ Result lblSwitchBacklightOn(u64 fade_time) {
 Result lblSwitchBacklightOff(u64 fade_time) {
     return _lblSwitchBacklight(7, fade_time);
 }
+
+Result lblSetCurrentBrightnessSetting(float brightness) {
+    IpcCommand c;
+    ipcInitialize(&c);
+
+    struct {
+        u64 magic;
+        u64 cmd_id;
+        float value;
+    } *raw;
+
+    raw = serviceIpcPrepareHeader(&g_lblSrv, &c, sizeof(*raw));
+
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 2;
+    raw->value = brightness;
+
+    Result rc = serviceIpcDispatch(&g_lblSrv);
+
+    if (R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        struct {
+            u64 magic;
+            u64 result;
+        } *resp;
+
+        serviceIpcParse(&g_lblSrv, &r, sizeof(*resp));
+        resp = r.Raw;
+
+        rc = resp->result;
+    }
+
+    return rc;
+}
+
+Result lblGetCurrentBrightnessSetting(float *out_value) {
+    IpcCommand c;
+    ipcInitialize(&c);
+
+    struct {
+        u64 magic;
+        u64 cmd_id;
+    } *raw;
+
+    raw = serviceIpcPrepareHeader(&g_lblSrv, &c, sizeof(*raw));
+
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 3;
+
+    Result rc = serviceIpcDispatch(&g_lblSrv);
+
+    if (R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        struct {
+            u64 magic;
+            u64 result;
+            float brightness;
+        } *resp;
+
+        serviceIpcParse(&g_lblSrv, &r, sizeof(*resp));
+        resp = r.Raw;
+
+        rc = resp->result;
+        if (R_SUCCEEDED(rc))
+            *out_value = resp->brightness;
+    }
+
+    return rc;
+}
+
+Result lblEnableAutoBrightnessControl(void) {
+    return _lblCmdNoIO(12);
+}
+
+Result lblDisableAutoBrightnessControl(void) {
+    return _lblCmdNoIO(13);    
+}
+
+Result lblIsAutoBrightnessControlEnabled(bool *out_value){
+    IpcCommand c;
+    ipcInitialize(&c);
+
+    struct {
+        u64 magic;
+        u64 cmd_id;
+    } *raw;
+
+    raw = serviceIpcPrepareHeader(&g_lblSrv, &c, sizeof(*raw));
+
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 14;
+
+    Result rc = serviceIpcDispatch(&g_lblSrv);
+
+    if (R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        struct {
+            u64 magic;
+            u64 result;
+            u8 isEnabled;
+        } *resp;
+
+        serviceIpcParse(&g_lblSrv, &r, sizeof(*resp));
+        resp = r.Raw;
+
+        rc = resp->result;
+        if (R_SUCCEEDED(rc))
+            *out_value = resp->isEnabled != 0;
+    }
+
+    return rc;
+}