boot: implement I2cResourceManager

stratosphere/boot/source/i2c_driver/i2c_resource_manager.hpp

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2018-2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include <switch.h>
+#include <stratosphere.hpp>
+
+#include "i2c_types.hpp"
+#include "i2c_bus_accessor.hpp"
+#include "i2c_driver_session.hpp"
+
+class I2cResourceManager {
+    public:
+        static constexpr size_t MaxDriverSessions = 40;
+        static constexpr size_t MaxBuses = 6;
+        static constexpr size_t PowerBusId = static_cast<size_t>(I2cBus_I2c5);
+        static constexpr size_t InvalidSessionId = static_cast<size_t>(-1);
+    private:
+        HosMutex initialize_mutex;
+        HosMutex session_open_mutex;
+        size_t ref_cnt = 0;
+        bool suspended = false;
+        bool power_bus_suspended = false;
+        I2cDriverSession sessions[MaxDriverSessions];
+        I2cBusAccessor bus_accessors[MaxBuses];
+        HosMutex transaction_mutexes[MaxBuses];
+    public:
+        I2cResourceManager() {
+            /* ... */
+        }
+    private:
+        size_t GetFreeSessionId() const;
+    public:
+        /* N uses a singleton here, we'll oblige. */
+        static I2cResourceManager &GetInstance() {
+            static I2cResourceManager s_instance;
+            return s_instance;
+        }
+
+        bool IsInitialized() const {
+            return this->ref_cnt > 0;
+        }
+
+        I2cDriverSession& GetSession(size_t id) {
+            return this->sessions[id];
+        }
+
+        HosMutex& GetTransactionMutex(I2cBus bus) {
+            if (bus >= MaxBuses) {
+                std::abort();
+            }
+            return this->transaction_mutexes[bus];
+        }
+
+        void Initialize();
+        void Finalize();
+
+        void OpenSession(I2cSessionImpl *out_session, I2cBus bus, u32 slave_address, AddressingMode addressing_mode, SpeedMode speed_mode, u32 max_retries, u64 retry_wait_time);
+        void CloseSession(const I2cSessionImpl &session);
+        void SuspendBuses();
+        void ResumeBuses();
+        void SuspendPowerBus();
+        void ResumePowerBus();
+};
+