i2c/gpio: hook up open session for sf interface

libraries/libstratosphere/include/stratosphere/i2c/i2c_bus_api.hpp

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2018-2020 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 <vapours.hpp>
+#include <stratosphere/i2c/i2c_types.hpp>
+
+namespace ams::i2c {
+
+    struct I2cSession {
+        void *_session;
+    };
+
+    Result OpenSession(I2cSession *out, DeviceCode device_code);
+    void CloseSession(I2cSession &session);
+
+    Result Send(const I2cSession &session, const void *src, size_t src_size, TransactionOption option);
+    Result Receive(void *dst, size_t dst_size, const I2cSession &session, TransactionOption option);
+
+    Result ExecuteCommandList(void *dst, size_t dst_size, const I2cSession &session, const void *src, size_t src_size);
+
+    void SetRetryPolicy(const I2cSession &session, int max_retry_count, int retry_interval_ms);
+
+}