2 * A library of polled 16550 serial routines. These are intended to
3 * be used to support progress messages, xmon, kgdb, etc. on a
4 * variety of platforms.
6 * Adapted from lots of code ripped from the arch/ppc/boot/ polled
9 * Author: Matt Porter <mporter@mvista.com>
11 * 2002-2003 (c) MontaVista Software, Inc. This file is licensed under
12 * the terms of the GNU General Public License version 2. This program
13 * is licensed "as is" without any warranty of any kind, whether express
17 #include <linux/types.h>
18 #include <linux/serial.h>
19 #include <linux/tty.h> /* For linux/serial_core.h */
20 #include <linux/serial_core.h>
21 #include <linux/serialP.h>
22 #include <linux/serial_reg.h>
23 #include <asm/machdep.h>
24 #include <asm/serial.h>
27 #define SERIAL_BAUD 9600
29 /* SERIAL_PORT_DFNS is defined in <asm/serial.h> */
30 #ifndef SERIAL_PORT_DFNS
31 #define SERIAL_PORT_DFNS
34 static struct serial_state rs_table[RS_TABLE_SIZE] = {
35 SERIAL_PORT_DFNS /* defined in <asm/serial.h> */
38 static void (*serial_outb)(unsigned long, unsigned char);
39 static unsigned long (*serial_inb)(unsigned long);
43 unsigned long direct_inb(unsigned long addr)
45 return readb((void __iomem *)addr);
48 void direct_outb(unsigned long addr, unsigned char val)
50 writeb(val, (void __iomem *)addr);
53 unsigned long io_inb(unsigned long port)
58 void io_outb(unsigned long port, unsigned char val)
63 unsigned long serial_init(int chan, void *ignored)
65 unsigned long com_port;
66 unsigned char lcr, dlm;
68 /* We need to find out which type io we're expecting. If it's
69 * 'SERIAL_IO_PORT', we get an offset from the isa_io_base.
70 * If it's 'SERIAL_IO_MEM', we can the exact location. -- Tom */
71 switch (rs_table[chan].io_type) {
73 com_port = rs_table[chan].port;
74 serial_outb = io_outb;
78 com_port = (unsigned long)rs_table[chan].iomem_base;
79 serial_outb = direct_outb;
80 serial_inb = direct_inb;
83 /* We can't deal with it. */
87 /* How far apart the registers are. */
88 shift = rs_table[chan].iomem_reg_shift;
91 lcr = serial_inb(com_port + (UART_LCR << shift));
93 /* Access baud rate */
94 serial_outb(com_port + (UART_LCR << shift), UART_LCR_DLAB);
95 dlm = serial_inb(com_port + (UART_DLM << shift));
98 * Test if serial port is unconfigured
99 * We assume that no-one uses less than 110 baud or
100 * less than 7 bits per character these days.
103 if ((dlm <= 4) && (lcr & 2)) {
104 /* port is configured, put the old LCR back */
105 serial_outb(com_port + (UART_LCR << shift), lcr);
109 serial_outb(com_port + (UART_DLL << shift),
110 (rs_table[chan].baud_base / SERIAL_BAUD) & 0xFF);
111 serial_outb(com_port + (UART_DLM << shift),
112 (rs_table[chan].baud_base / SERIAL_BAUD) >> 8);
113 /* 8 data, 1 stop, no parity */
114 serial_outb(com_port + (UART_LCR << shift), 0x03);
116 serial_outb(com_port + (UART_MCR << shift), 0x03);
118 /* Clear & enable FIFOs */
119 serial_outb(com_port + (UART_FCR << shift), 0x07);
126 serial_putc(unsigned long com_port, unsigned char c)
128 while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0)
130 serial_outb(com_port, c);
134 serial_getc(unsigned long com_port)
136 while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0)
138 return serial_inb(com_port);
142 serial_tstc(unsigned long com_port)
144 return ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0);
148 serial_close(unsigned long com_port)
153 gen550_init(int i, struct uart_port *serial_req)
155 rs_table[i].io_type = serial_req->iotype;
156 rs_table[i].port = serial_req->iobase;
157 rs_table[i].iomem_base = serial_req->membase;
158 rs_table[i].iomem_reg_shift = serial_req->regshift;
159 rs_table[i].baud_base = serial_req->uartclk ? serial_req->uartclk / 16 : BASE_BAUD;
162 #ifdef CONFIG_SERIAL_TEXT_DEBUG
164 gen550_progress(char *s, unsigned short hex)
166 volatile unsigned int progress_debugport;
169 progress_debugport = serial_init(0, NULL);
171 serial_putc(progress_debugport, '\r');
173 while ((c = *s++) != 0)
174 serial_putc(progress_debugport, c);
176 serial_putc(progress_debugport, '\n');
177 serial_putc(progress_debugport, '\r');
179 #endif /* CONFIG_SERIAL_TEXT_DEBUG */