incubator-nuttx/include/nuttx/serial.h

300 lines
12 KiB
C

/************************************************************************************
* serial.h
*
* Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************************/
#ifndef __SERIAL_H
#define __SERIAL_H
/************************************************************************************
* Included Files
************************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <semaphore.h>
#include <nuttx/fs.h>
/************************************************************************************
* Definitions
************************************************************************************/
/* Maximum number of threads than can be waiting for POLL events */
#ifndef CONFIG_DEV_CONSOLE_NPOLLWAITERS
# define CONFIG_DEV_CONSOLE_NPOLLWAITERS 2
#endif
/* vtable access helpers */
#define uart_setup(dev) dev->ops->setup(dev)
#define uart_shutdown(dev) dev->ops->shutdown(dev)
#define uart_attach(dev) dev->ops->attach(dev)
#define uart_detach(dev) dev->ops->detach(dev)
#define uart_enabletxint(dev) dev->ops->txint(dev, TRUE)
#define uart_disabletxint(dev) dev->ops->txint(dev, FALSE)
#define uart_enablerxint(dev) dev->ops->rxint(dev, TRUE)
#define uart_disablerxint(dev) dev->ops->rxint(dev, FALSE)
#define uart_rxavailable(dev) dev->ops->rxavailable(dev)
#define uart_txready(dev) dev->ops->txready(dev)
#define uart_txempty(dev) dev->ops->txempty(dev)
#define uart_send(dev,ch) dev->ops->send(dev,ch)
#define uart_receive(dev,s) dev->ops->receive(dev,s)
/************************************************************************************
* Public Types
************************************************************************************/
/* This structure defines one serial I/O buffer. The serial infrastructure will
* initialize the 'sem' field but all other fields must be initialized by the
* caller of uart_register().
*/
struct uart_buffer_s
{
sem_t sem; /* Used to control exclusive access to the buffer */
volatile sint16 head; /* Index to the head [IN] index in the buffer */
volatile sint16 tail; /* Index to the tail [OUT] index in the buffer */
sint16 size; /* The allocated size of the buffer */
FAR char *buffer; /* Pointer to the allocated buffer memory */
};
/* This structure defines all of the operations providd by the architecture specific
* logic. All fields must be provided with non-NULL function pointers by the
* caller of uart_register().
*/
struct uart_dev_s;
struct uart_ops_s
{
/* Configure the UART baud, bits, parity, fifos, etc. This method is called
* the first time that the serial port is opened. For the serial console,
* this will occur very early in initialization; for other serial ports this
* will occur when the port is first opened. This setup does not include
* attaching or enabling interrupts. That portion of the UART setup is
* performed when the attach() method is called.
*/
CODE int (*setup)(FAR struct uart_dev_s *dev);
/* Disable the UART. This method is called when the serial port is closed.
* This method reverses the operation the setup method. NOTE that the serial
* console is never shutdown.
*/
CODE void (*shutdown)(FAR struct uart_dev_s *dev);
/* Configure the UART to operation in interrupt driven mode. This method is
* called when the serial port is opened. Normally, this is just after the
* the setup() method is called, however, the serial console may operate in
* a non-interrupt driven mode during the boot phase.
*
* RX and TX interrupts are not enabled when by the attach method (unless the
* hardware supports multiple levels of interrupt enabling). The RX and TX
* interrupts are not enabled until the txint() and rxint() methods are called.
*/
CODE int (*attach)(FAR struct uart_dev_s *dev);
/* Detach UART interrupts. This method is called when the serial port is
* closed normally just before the shutdown method is called. The exception is
* the serial console which is never shutdown.
*/
CODE void (*detach)(FAR struct uart_dev_s *dev);
/* All ioctl calls will be routed through this method */
CODE int (*ioctl)(FAR struct file *filep, int cmd, unsigned long arg);
/* Called (usually) from the interrupt level to receive one character from
* the UART. Error bits associated with the receipt are provided in the
* the return 'status'.
*/
CODE int (*receive)(FAR struct uart_dev_s *dev, unsigned int *status);
/* Call to enable or disable RX interrupts */
CODE void (*rxint)(FAR struct uart_dev_s *dev, boolean enable);
/* Return TRUE if the receive data is available */
CODE boolean (*rxavailable)(FAR struct uart_dev_s *dev);
/* This method will send one byte on the UART */
CODE void (*send)(FAR struct uart_dev_s *dev, int ch);
/* Call to enable or disable TX interrupts */
CODE void (*txint)(FAR struct uart_dev_s *dev, boolean enable);
/* Return TRUE if the tranmsit hardware is ready to send another byte. This
* is used to determine if send() method can be called.
*/
CODE boolean (*txready)(FAR struct uart_dev_s *dev);
/* Return TRUE if all characters have been sent. If for example, the UART
* hardware implements FIFOs, then this would mean the the transmit FIFO is
* empty. This method is called when the driver needs to make sure that
* all characters are "drained" from the TX hardware.
*/
CODE boolean (*txempty)(FAR struct uart_dev_s *dev);
};
/* This is the device structure used by the driver. The caller of
* uart_register() must allocate and initialize this structure. The
* calling logic need only set all fields to zero except:
*
* 'isconsole', 'xmit.buffer', 'rcv.buffer', the elements
* of 'ops', and 'private'
*
* The common logic will initialize all semaphores.
*/
struct uart_dev_s
{
ubyte open_count; /* Number of times the device has been opened */
volatile boolean xmitwaiting; /* TRUE: User waiting for space in xmit.buffer */
volatile boolean recvwaiting; /* TRUE: User waiting for data in recv.buffer */
boolean isconsole; /* TRUE: This is the serial console */
sem_t closesem; /* Locks out new open while close is in progress */
sem_t xmitsem; /* Wakeup user waiting for space in xmit.buffer */
sem_t recvsem; /* Wakeup user waiting for data in recv.buffer */
#ifndef CONFIG_DISABLE_POLL
sem_t pollsem; /* Manages exclusive access to fds[] */
#endif
struct uart_buffer_s xmit; /* Describes transmit buffer */
struct uart_buffer_s recv; /* Describes receive buffer */
FAR const struct uart_ops_s *ops; /* Arch-specific operations */
FAR void *priv; /* Used by the arch-specific logic */
/* The following is a list if poll structures of threads waiting for
* driver events. The 'struct pollfd' reference for each open is also
* retained in the f_priv field of the 'struct file'.
*/
#ifndef CONFIG_DISABLE_POLL
struct pollfd *fds[CONFIG_DEV_CONSOLE_NPOLLWAITERS];
#endif
};
typedef struct uart_dev_s uart_dev_t;
/************************************************************************************
* Public Data
************************************************************************************/
/************************************************************************************
* Public Functions
************************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif
/************************************************************************************
* Name: uart_register
*
* Description:
* Register serial console and serial ports.
*
************************************************************************************/
EXTERN int uart_register(FAR const char *path, FAR uart_dev_t *dev);
/************************************************************************************
* Name: uart_xmitchars
*
* Description:
* This function is called from the UART interrupt handler when an interrupt
* is received indicating that there is more space in the transmit FIFO. This
* function will send characters from the tail of the xmit buffer while the driver
* write() logic adds data to the head of the xmit buffer.
*
************************************************************************************/
EXTERN void uart_xmitchars(FAR uart_dev_t *dev);
/************************************************************************************
* Name: uart_receivechars
*
* Description:
* This function is called from the UART interrupt handler when an interrupt
* is received indicating that are bytes available to be received. This
* function will add chars to head of receive buffer. Driver read() logic will take
* characters from the tail of the buffer.
*
************************************************************************************/
EXTERN void uart_recvchars(FAR uart_dev_t *dev);
/************************************************************************************
* Name: uart_datareceived
*
* Description:
* This function is called from uart_recvchars when new serial data is place in
* the driver's circular buffer. This function will wake-up any stalled read()
* operations that are waiting for incoming data.
*
************************************************************************************/
EXTERN void uart_datareceived(FAR uart_dev_t *dev);
/************************************************************************************
* Name: uart_datasent
*
* Description:
* This function is called from uart_xmitchars after serial data has been sent,
* freeing up some space in the driver's circular buffer. This function will
* wake-up any stalled write() operations that was waiting for space to buffer
* outgoing data.
*
************************************************************************************/
EXTERN void uart_datasent(FAR uart_dev_t *dev);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __SERIAL_H */