android-things: Prep for peripheralmanager support

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

include/peripheralmanager/uart_device.h

@@ -0,0 +1,183 @@
+/*
+ * 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>
+#include <termios.h>
+#include <unistd.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.
+/// @{
+
+/// UART Parity
+enum UartParity {
+  UART_PARITY_NONE, /**< No parity */
+  UART_PARITY_EVEN, /**< Even parity */
+  UART_PARITY_ODD,  /**< Odd parity */
+  UART_PARITY_MARK, /**< Mark parity, always 1 */
+  UART_PARITY_SPACE /**< Space parity, always 0 */
+};
+
+/// Modem control Bits
+enum UartModemControlBits {
+  UART_MC_LE = TIOCM_LE,   /**< Data set ready/Line enable */
+  UART_MC_DTR = TIOCM_DTR, /**< Data terminal ready */
+  UART_MC_RTS = TIOCM_RTS, /**< Request to send */
+  UART_MC_ST = TIOCM_ST,   /**< Secondary TXD */
+  UART_MC_SR = TIOCM_SR,   /**< Secondary RXD */
+  UART_MC_CTS = TIOCM_CTS, /**< Clear to send */
+  UART_MC_CD = TIOCM_CAR,  /**< Data carrier detect */
+  UART_MC_RI = TIOCM_RI,   /**< Ring */
+  UART_MC_DSR = TIOCM_DSR  /**< Data set ready */
+};
+
+// Hardware Flow Control
+enum UartHardwareFlowControlType {
+  UART_HW_FLOW_NONE,       /**< No hardware flow control */
+  UART_HW_FLOW_AUTO_RTSCTS /**< Auto RTS/CTS */
+};
+
+/// Flush queue selection
+enum UartFlushQueueSelection {
+  UART_FLUSH_IN = TCIFLUSH,     /**< Flushes data received but not read */
+  UART_FLUSH_OUT = TCOFLUSH,    /**< Flushes data written but not transmitted */
+  UART_FLUSH_IN_OUT = TCIOFLUSH /**< Flushes both in and out */
+};
+
+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 baudrate Speed in baud.
+/// @return 0 on success, errno on error.
+int BUartDevice_setBaudrate(const BUartDevice* device, uint32_t baudrate);
+
+/// Sets number of stop bits for the UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param stop_bits Number of stop bits. Typically 1 or 2.
+/// @return 0 on success, errno on error.
+int BUartDevice_setStopBits(const BUartDevice* device, uint32_t stop_bits);
+
+/// Sets the data size of a character for the UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param data_size Number of bits per character. Typically between 5 and 8.
+/// @return 0 on success, errno on error.
+int BUartDevice_setDataSize(const BUartDevice* device, uint32_t data_size);
+
+/// Sets the parity mode for the UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param mode Parity mode. One of UART_PARITY_NONE, UART_PARITY_EVEN,
+/// UART_PARITY_ODD, UART_PARITY_MARK, UART_PARITY_SPACE.
+/// @return 0 on success, errno on error.
+int BUartDevice_setParity(const BUartDevice* device, uint32_t mode);
+
+/// Sets the hardware flow control mode for the UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param mode Flow control mode. Either UART_HW_FLOW_NONE or
+/// UART_HW_FLOW_AUTO_RTSCTS.
+/// @return 0 on success, errno on error.
+int BUartDevice_setHardwareFlowControl(const BUartDevice* device,
+                                       uint32_t mode);
+
+/// Sets the modem control bits for the UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param bits Modem control bits to set.
+/// @return 0 on success, errno on error.
+int BUartDevice_setModemControl(const BUartDevice* device, uint32_t bits);
+
+/// Clears the modem control bits for the UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param bits Modem control bits to clear.
+/// @return 0 on success, errno on error.
+int BUartDevice_clearModemControl(const BUartDevice* device, uint32_t bits);
+
+/// Sends a break to the UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param duration Duration of break transmission in milliseconds. If 0,
+/// transmits zero-valued bits for at least 0.25 seconds, and not more
+/// than 0.5 seconds.
+/// @return 0 on success, errno on error.
+int BUartDevice_sendBreak(const BUartDevice* device, uint32_t duration_msecs);
+
+/// Flushes specified queue for the UART device.
+/// @param device Pointer to the BUartDevice struct.
+/// @param queue Queue to flush. One of UART_FLUSH_IN, UART_FLUSH_OUT,
+/// UART_FLUSH_IN_OUT.
+/// @return 0 on success, errno on error.
+int BUartDevice_flush(const BUartDevice* device, uint32_t queue);
+
+/// Gets a file descriptor to be notified when data can be read.
+///
+/// You can use this file descriptor to poll on incoming data instead of
+/// actively reading for new data.
+///
+/// @param device Pointer to the BUartDevice struct.
+/// @param fd Output pointer to the file descriptor.
+/// @return 0 on success, errno on error.
+int BUartDevice_getPollingFd(const BUartDevice* device, int* fd);
+
+/// Acknowledges an input event.
+///
+/// This must be called after receiving an event notification on the polling
+/// file descriptor.
+/// If you don't acknowledge an event, peripheral manager will assume you are
+/// still processing it and you will not receive any more events.
+/// If you acknowledge an event before reading the data from the device, you
+/// will receive an event immediately as there will still be data available.
+///
+/// @param fd File descriptor to acknowledge the event on.
+/// @return 0 on success, errno on error.
+int BUartDevice_ackInputEvent(int fd);
+
+/// Destroys a BUartDevice struct.
+/// @param device Pointer to the BUartDevice struct.
+void BUartDevice_delete(BUartDevice* device);
+
+/// @}
+
+__END_DECLS
+
+#endif  // SYSTEM_PERIPHERALMANAGER_UART_DEVICE_H_