Implement the client side UART interface.

This CL adds the C APIs to act on UART devices as well as unit tests and
an example.

Bug: 27898961

Change-Id: I23f627d69fb3440fec53bded20bd3b408c9ed591

2 files changed, 93 insertions, 2 deletions

diff --git a/include/peripheralmanager/peripheral_manager_client.h b/include/peripheralmanager/peripheral_manager_client.h
index 5fdc5ff..51821b0 100644
--- a/include/peripheralmanager/peripheral_manager_client.h
+++ b/include/peripheralmanager/peripheral_manager_client.h
@@ -23,6 +23,7 @@
 #include "peripheralmanager/i2c_device.h"
 #include "peripheralmanager/led.h"
 #include "peripheralmanager/spi_device.h"
+#include "peripheralmanager/uart_device.h"
 
 __BEGIN_DECLS
 
@@ -97,8 +98,9 @@ char** BPeripheralManagerClient_listI2cBuses(
     int* num_i2c_buses);
 
 /// Opens an I2C device and takes ownership of it.
-/// @oaram client Pointer to the BPeripheralManagerClient struct.
-/// @param name Name of the SPI device.
+/// @param client Pointer to the BPeripheralManagerClient struct.
+/// @param name Name of the I2C bus.
+/// @param address Address of the I2C device.
 /// @param dev Output pointer to the BI2cDevice struct. Empty on error.
 /// @return 0 on success, errno on error
 int BPeripheralManagerClient_openI2cDevice(
@@ -107,6 +109,25 @@ int BPeripheralManagerClient_openI2cDevice(
     uint32_t address,
     BI2cDevice** dev);
 
+/// Returns the list of UART buses.
+/// This does not take ownership into account.
+/// The list must be freed by the caller.
+/// @param client Pointer to the BPeripheralManagerClient struct.
+/// @param num_uart_buses Output pointer to the number of element in the list.
+/// @return The list of uart buses.
+char** BPeripheralManagerClient_listUartDevices(
+    const BPeripheralManagerClient* client, int* num_uart_buses);
+
+/// Opens an UART device and takes ownership of it.
+/// @param client Pointer to the BPeripheralManagerClient struct.
+/// @param name Name of the UART device.
+/// @param dev Output pointer to the BUartDevice struct. Empty on error.
+/// @return 0 on success, errno on error
+int BPeripheralManagerClient_openUartDevice(
+    const BPeripheralManagerClient* client,
+    const char* name,
+    BUartDevice** dev);
+
 /// Creates a new client.
 /// @return A pointer to the created client. nullptr on errors.
 BPeripheralManagerClient* BPeripheralManagerClient_new();
diff --git a/include/peripheralmanager/uart_device.h b/include/peripheralmanager/uart_device.h
new file mode 100644
index 0000000..057a068
--- /dev/null
+++ b/include/peripheralmanager/uart_device.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SYSTEM_PERIPHERALMANAGER_UART_DEVICE_H_
+#define SYSTEM_PERIPHERALMANAGER_UART_DEVICE_H_
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+__BEGIN_DECLS
+
+/// @defgroup Uart Uart device interface
+/// @brief Functions to control an UART device.
+///
+/// These functions can be used to control an UART device.
+/// @{
+
+typedef struct BUartDevice BUartDevice;
+
+/// Writes to a UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param data Data to write.
+/// @param len Size of the data to write.
+/// @param bytes_written Output pointer to the number of bytes written.
+/// @return 0 on success, errno on error.
+int BUartDevice_write(const BUartDevice* device,
+                      const void* data,
+                      uint32_t len,
+                      uint32_t* bytes_written);
+
+/// Reads from a UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param data Buffer to read the data into.
+/// @param len Number of bytes to read.
+/// @param bytes_read Output pointer to the number of bytes read.
+/// @return 0 on success, errno on error.
+int BUartDevice_read(const BUartDevice* device,
+                     void* data,
+                     uint32_t len,
+                     uint32_t* bytes_read);
+
+/// Sets the input and output speed of a UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param device Uart device to configure.
+/// @param baudrate Speed in baud.
+/// @return 0 on success, errno on error.
+int BUartDevice_setBaudrate(const BUartDevice* device, uint32_t baudrate);
+
+/// Destroys a BUartDevice struct.
+/// @param device Pointer to the BUartDevice struct.
+void BUartDevice_delete(BUartDevice* device);
+
+/// @}
+
+__END_DECLS
+
+#endif  // SYSTEM_PERIPHERALMANAGER_UART_DEVICE_H_