Add psm service and psmGetBatteryChargePercentage function (fixed) (#166)

nx/include/switch.h

@@ -48,6 +48,7 @@ extern "C" {
 #include "switch/services/audren.h"
 #include "switch/services/csrng.h"
 #include "switch/services/bpc.h"
+#include "switch/services/psm.h"
 //#include "switch/services/bsd.h" Use switch/runtime/devices/socket.h instead
 #include "switch/services/fatal.h"
 #include "switch/services/time.h"

nx/include/switch/services/psm.h

@@ -0,0 +1,13 @@
+/**
+ * @file psm.h
+ * @brief PSM service IPC wrapper.
+ * @author XorTroll
+ * @copyright libnx Authors
+ */
+#pragma once
+#include "../types.h"
+
+Result psmInitialize(void);
+void psmExit(void);
+
+Result psmGetBatteryChargePercentage(u32 *out);

nx/source/services/psm.c

@@ -0,0 +1,67 @@
+#include "types.h"
+#include "result.h"
+#include "arm/atomics.h"
+#include "kernel/ipc.h"
+#include "kernel/detect.h"
+#include "services/psm.h"
+#include "services/sm.h"
+
+static Service g_psmSrv;
+static u64 g_refCnt;
+
+Result psmInitialize(void)
+{
+    Result rc = 0;
+    
+    atomicIncrement64(&g_refCnt);
+
+    if (serviceIsActive(&g_psmSrv))
+        return 0;
+
+    rc = smGetService(&g_psmSrv, "psm");
+
+    return rc;
+}
+
+void psmExit(void)
+{
+    if (atomicDecrement64(&g_refCnt) == 0)
+        serviceClose(&g_psmSrv);
+}
+
+Result psmGetBatteryChargePercentage(u32 *out)
+{
+    IpcCommand c;
+    ipcInitialize(&c);
+    
+    struct {
+        u64 magic;
+        u64 cmd_id;
+    } *raw;
+    
+    raw = ipcPrepareHeader(&c, sizeof(*raw));
+    
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 0;
+    
+    Result rc = serviceIpcDispatch(&g_psmSrv);
+    
+    if(R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        ipcParse(&r);
+        
+        struct {
+            u64 magic;
+            u64 result;
+            u32 percentage;
+        } *resp = r.Raw;
+        
+        rc = resp->result;
+        
+        if (R_SUCCEEDED(rc)) {
+            *out = resp->percentage;
+        }
+    }
+    
+    return rc;
+}