boot: implement I2cBusAccessor

stratosphere/boot/source/i2c_driver/i2c_bus_accessor.hpp

@@ -0,0 +1,79 @@
+/*
+ * 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_registers.hpp"
+
+class I2cBusAccessor {
+    private:
+        enum TransferMode {
+            TransferMode_Send = 0,
+            TransferMode_Receive = 1,
+        };
+        static constexpr u64 InterruptTimeout = 100'000'000ul;
+    private:
+        Event interrupt_event;
+        HosMutex open_mutex;
+        HosMutex register_mutex;
+        I2cRegisters *i2c_registers = nullptr;
+        ClkRstRegisters clkrst_registers;
+        SpeedMode speed_mode = SpeedMode_Fast;
+        size_t open_sessions = 0;
+        I2cBus bus = I2cBus_I2c1;
+        PcvModule pcv_module = PcvModule_I2C1;
+        bool suspended = false;
+    public:
+        I2cBusAccessor() {
+            /* ... */
+        }
+    private:
+        inline void ClearInterruptMask() const {
+            WriteRegister(&i2c_registers->I2C_INTERRUPT_MASK_REGISTER_0, 0);
+            ReadRegister(&i2c_registers->I2C_INTERRUPT_MASK_REGISTER_0);
+        }
+
+        void SetBus(I2cBus bus);
+        void CreateInterruptEvent(I2cBus bus);
+        void SetClock(SpeedMode speed_mode);
+
+        void ResetController() const;
+        void ClearBus() const;
+        void DisableClock();
+        void SetPacketMode();
+        Result FlushFifos();
+
+        Result GetTransactionResult() const;
+        void HandleTransactionResult(Result result);
+        Result GetAndHandleTransactionResult();
+
+        void WriteTransferHeader(TransferMode transfer_mode, I2cTransactionOption option, AddressingMode addressing_mode, u32 slave_address, size_t num_bytes);
+    public:
+        void Open(I2cBus bus, SpeedMode speed_mode);
+        void Close();
+        void Suspend();
+        void Resume();
+        void DoInitialConfig();
+
+        size_t GetOpenSessions() const;
+        bool GetBusy() const;
+
+        Result Send(const u8 *data, size_t num_bytes, I2cTransactionOption option, AddressingMode addressing_mode, u32 slave_address);
+        Result Receive(u8 *out_data, size_t num_bytes, I2cTransactionOption option, AddressingMode addressing_mode, u32 slave_address);
+};