serial.h

讲述linux的初始化过程

/*
 * include/asm-arm/arch-sa1100/serial.h
 * (C) 1999 Nicolas Pitre <[e-mail]>
 *
 * All this is intended to be used with a 16550-like UART on the SA1100's 
 * PCMCIA bus.  It has nothing to do with the SA1100's internal serial ports.
 * This is included by serial.c -- serial_sa1100.c makes no use of it.
 */


/*
 * This assumes you have a 1.8432 MHz clock for your UART.
 *
 * It'd be nice if someone built a serial card with a 24.576 MHz
 * clock, since the 16550A is capable of handling a top speed of 1.5
 * megabits/second; but this requires the faster clock.
 */
#define BASE_BAUD ( 1843200 / 16 )

/* Standard COM flags */
#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)

#define RS_TABLE_SIZE 4

#define STD_SERIAL_PORT_DEFNS			\
	/* UART CLK   PORT IRQ     FLAGS        */			\
	{ 0, BASE_BAUD, 0x3F8, IRQ_GPIO3, STD_COM_FLAGS },	/* ttyS0 */	\
	{ 0, BASE_BAUD, 0x2F8, IRQ_GPIO3, STD_COM_FLAGS },	/* ttyS1 */	\
	{ 0, BASE_BAUD, 0x3E8, IRQ_GPIO3, STD_COM_FLAGS },	/* ttyS2 */	\
	{ 0, BASE_BAUD, 0x2E8, IRQ_GPIO3, STD_COM4_FLAGS }	/* ttyS3 */