serial_driver.h

一个简单的小型操作系统

/*****************************************************************************
 * 
 * Module       : serial_driver.h
 * Description  : low level serial device driver interface
 * OS           : SLOS 0.09
 * Platform     : e7t
 * History      : 
 *
 * 25th November 2001 Andrew N. Sloss
 * - create serial implementation
 *
 *****************************************************************************/

#define COM1			(1)
#define COM0			(0)

/* -- serial_init -------------------------------------------------------------
 *
 * Description : initalize serial driver.
 * 
 * Parameters  : none...
 * Return      : none...
 * Notes       : none...
 *
 *  Initializes the node data structures
 */

void serial_init(void);

/* -- serial_open -------------------------------------------------------------
 *
 * Description : open the serial device driver
 * 
 * Parameters  : unsigned major - DEVICE_SEGMENT_E7T 
 *             : unsigned com - COM0 | COM1
 * Return      : if (success) return UART0_BASE or UART1_BASE 
 *                  else if (alreadyopen) return DEVICE_IN_USE
 *                  else if (unknown) return DEVICE_NEXT
 * Notes       : 
 *
 */

UID serial_open(unsigned major,unsigned com);

/* -- serial_close ------------------------------------------------------------
 *
 * Description : close serial device driver
 * 
 * Parameters  : UID id 
 * Return      : 
 *   DEVICE_SUCCESS - successfully close the device
 *   DEVICE_UNKNOWN - couldn't identify the UID
 * Notes       : 
 *
 */

int serial_close(UID id);

/* -- serial_write_byte -------------------------------------------------------
 *
 * Description : waits for response from hardware and writes a 
 *               byte to the device 
 * 
 * Parameters  : UART port address
 *             : BYTE data
 * Return      : none...
 *
 * Notes       : an example of a led write bit
 *
 */

void internal_serial_write(unsigned int port,BYTE c);

/* -- serial_write_byte -------------------------------------------------------
 *
 * Description : write a byte to a serial device 
 * 
 * Parameters  : UID device
 *             : BYTE data
 * Return      : none...
 *
 * Notes       : an example of a led write bit
 *
 */

void serial_write_byte(UID id,BYTE data);

/* -- serial_read_byte --------------------------------------------------------
 *
 * Description : read a particular byte value
 * 
 * Parameters  : UID id - COM0 | COM1 
 * Return      : BYTE - read byte otherwise 255
 *
 * Notes       :
 */

BYTE  serial_read_byte(UID id);