boot: implement I2cDriverSession

stratosphere/boot/source/i2c_driver/i2c_bus_accessor.cpp

@@ -129,6 +129,19 @@ bool I2cBusAccessor::GetBusy() const {
     return false;
 }
 
+void I2cBusAccessor::OnStartTransaction() const {
+    /* Nothing actually happens here. */
+}
+
+void I2cBusAccessor::OnStopTransaction() const {
+    /* Nothing actually happens here. */
+}
+
+Result I2cBusAccessor::StartTransaction(DriverCommand command, AddressingMode addressing_mode, u32 slave_address) {
+    /* Nothing actually happens here... */
+    return ResultSuccess;
+}
+
 Result I2cBusAccessor::Send(const u8 *data, size_t num_bytes, I2cTransactionOption option, AddressingMode addressing_mode, u32 slave_address) {
     std::scoped_lock<HosMutex> lk(this->register_mutex);
     const u8 *cur_src = data;

stratosphere/boot/source/i2c_driver/i2c_bus_accessor.hpp

@@ -74,6 +74,9 @@ class I2cBusAccessor {
         size_t GetOpenSessions() const;
         bool GetBusy() const;
 
+        void OnStartTransaction() const;
+        Result StartTransaction(DriverCommand command, AddressingMode addressing_mode, u32 slave_address);
         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);
+        void OnStopTransaction() const;
 };

stratosphere/boot/source/i2c_driver/i2c_driver_session.cpp

@@ -0,0 +1,108 @@
+/*
+ * 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/>.
+ */
+
+#include <switch.h>
+#include <stratosphere.hpp>
+
+#include "i2c_driver_session.hpp"
+
+void I2cDriverSession::Open(I2cBus bus, u32 slave_address, AddressingMode addr_mode, SpeedMode speed_mode, I2cBusAccessor *bus_accessor, u32 max_retries, u64 retry_wait_time){
+    std::scoped_lock<HosMutex> lk(this->bus_accessor_mutex);
+    if (!this->open) {
+        this->bus_accessor = bus_accessor;
+        this->bus = bus;
+        this->slave_address = slave_address;
+        this->addressing_mode = addr_mode;
+        this->max_retries = max_retries;
+        this->retry_wait_time = retry_wait_time;
+        this->bus_accessor->Open(this->bus, speed_mode);
+        this->open = true;
+    }
+}
+
+void I2cDriverSession::Start(){
+    std::scoped_lock<HosMutex> lk(this->bus_accessor_mutex);
+    if (this->open) {
+        if (this->bus_accessor->GetOpenSessions() == 1) {
+            this->bus_accessor->DoInitialConfig();
+        }
+    }
+}
+
+void I2cDriverSession::Close(){
+    std::scoped_lock<HosMutex> lk(this->bus_accessor_mutex);
+    if (this->open) {
+        this->bus_accessor->Close();
+        this->bus_accessor = nullptr;
+    }
+}
+
+bool I2cDriverSession::IsOpen() const{
+    return this->open;
+}
+
+Result I2cDriverSession::DoTransaction(void *dst, const void *src, size_t num_bytes, I2cTransactionOption option, DriverCommand command){
+    std::scoped_lock<HosMutex> lk(this->bus_accessor_mutex);
+    Result rc;
+
+    if (this->bus_accessor->GetBusy()) {
+        return ResultI2cBusBusy;
+    }
+
+    this->bus_accessor->OnStartTransaction();
+
+    if (R_SUCCEEDED((rc = this->bus_accessor->StartTransaction(command, this->addressing_mode, this->slave_address)))) {
+        switch (command) {
+            case DriverCommand_Send:
+                rc = this->bus_accessor->Send(reinterpret_cast<const u8 *>(src), num_bytes, option, this->addressing_mode, this->slave_address);
+                break;
+            case DriverCommand_Receive:
+                rc = this->bus_accessor->Receive(reinterpret_cast<u8 *>(dst), num_bytes, option, this->addressing_mode, this->slave_address);
+                break;
+            default:
+                std::abort();
+        }
+    }
+
+    this->bus_accessor->OnStopTransaction();
+
+    return rc;
+}
+
+Result I2cDriverSession::DoTransactionWithRetry(void *dst, const void *src, size_t num_bytes, I2cTransactionOption option, DriverCommand command){
+    Result rc;
+
+    size_t i = 0;
+    while (true) {
+        rc = this->DoTransaction(dst, src, num_bytes, option, command);
+        if (rc == ResultI2cTimedOut) {
+            i++;
+            if (i <= this->max_retries) {
+                svcSleepThread(this->retry_wait_time);
+                continue;
+            }
+            return ResultI2cBusBusy;
+        } else if (R_FAILED(rc)) {
+            return rc;
+        }
+        return ResultSuccess;
+    }
+    return rc;
+}

stratosphere/boot/source/i2c_driver/i2c_driver_session.hpp

@@ -0,0 +1,47 @@
+/*
+ * 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"
+
+class I2cDriverSession {
+    private:
+        HosMutex bus_accessor_mutex;
+        I2cBusAccessor *bus_accessor = nullptr;
+        I2cBus bus = I2cBus_I2c1;
+        u32 slave_address = 0;
+        AddressingMode addressing_mode = AddressingMode_7Bit;
+        u32 max_retries = 0;
+        u64 retry_wait_time = 0;
+        bool open = false;
+    public:
+        I2cDriverSession() {
+            /* ... */
+        }
+    public:
+        void Open(I2cBus bus, u32 slave_address, AddressingMode addr_mode, SpeedMode speed_mode, I2cBusAccessor *bus_accessor, u32 max_retries, u64 retry_wait_time);
+        void Start();
+        void Close();
+
+        bool IsOpen() const;
+
+        Result DoTransaction(void *dst, const void *src, size_t num_bytes, I2cTransactionOption option, DriverCommand command);
+        Result DoTransactionWithRetry(void *dst, const void *src, size_t num_bytes, I2cTransactionOption option, DriverCommand command);
+};

stratosphere/boot/source/i2c_driver/i2c_types.hpp

@@ -38,6 +38,11 @@ enum I2cBus {
     I2cBus_I2c6 = 5,
 };
 
+enum DriverCommand {
+    DriverCommand_Send = 0,
+    DriverCommand_Receive = 1,
+};
+
 bool IsI2cDeviceSupported(I2cDevice dev);
 I2cBus GetI2cDeviceBus(I2cDevice dev);
 u32 GetI2cDeviceSlaveAddress(I2cDevice dev);