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/config.h>
18 #include <linux/types.h>
19 #include <linux/serial.h>
20 #include <linux/tty.h> /* For linux/serial_core.h */
21 #include <linux/serial_core.h>
22 #include <linux/serialP.h>
23 #include <linux/serial_reg.h>
24 #include <asm/machdep.h>
25 #include <asm/serial.h>
28 #define SERIAL_BAUD 9600
30 /* SERIAL_PORT_DFNS is defined in <asm/serial.h> */
31 #ifndef SERIAL_PORT_DFNS
32 #define SERIAL_PORT_DFNS
35 static struct serial_state rs_table
[RS_TABLE_SIZE
] = {
36 SERIAL_PORT_DFNS
/* defined in <asm/serial.h> */
39 static void (*serial_outb
)(unsigned long, unsigned char);
40 static unsigned long (*serial_inb
)(unsigned long);
44 unsigned long direct_inb(unsigned long addr
)
46 return readb((void __iomem
*)addr
);
49 void direct_outb(unsigned long addr
, unsigned char val
)
51 writeb(val
, (void __iomem
*)addr
);
54 unsigned long io_inb(unsigned long port
)
59 void io_outb(unsigned long port
, unsigned char val
)
64 unsigned long serial_init(int chan
, void *ignored
)
66 unsigned long com_port
;
67 unsigned char lcr
, dlm
;
69 /* We need to find out which type io we're expecting. If it's
70 * 'SERIAL_IO_PORT', we get an offset from the isa_io_base.
71 * If it's 'SERIAL_IO_MEM', we can the exact location. -- Tom */
72 switch (rs_table
[chan
].io_type
) {
74 com_port
= rs_table
[chan
].port
;
75 serial_outb
= io_outb
;
79 com_port
= (unsigned long)rs_table
[chan
].iomem_base
;
80 serial_outb
= direct_outb
;
81 serial_inb
= direct_inb
;
84 /* We can't deal with it. */
88 /* How far apart the registers are. */
89 shift
= rs_table
[chan
].iomem_reg_shift
;
92 lcr
= serial_inb(com_port
+ (UART_LCR
<< shift
));
94 /* Access baud rate */
95 serial_outb(com_port
+ (UART_LCR
<< shift
), UART_LCR_DLAB
);
96 dlm
= serial_inb(com_port
+ (UART_DLM
<< shift
));
99 * Test if serial port is unconfigured
100 * We assume that no-one uses less than 110 baud or
101 * less than 7 bits per character these days.
104 if ((dlm
<= 4) && (lcr
& 2)) {
105 /* port is configured, put the old LCR back */
106 serial_outb(com_port
+ (UART_LCR
<< shift
), lcr
);
110 serial_outb(com_port
+ (UART_DLL
<< shift
),
111 (rs_table
[chan
].baud_base
/ SERIAL_BAUD
) & 0xFF);
112 serial_outb(com_port
+ (UART_DLM
<< shift
),
113 (rs_table
[chan
].baud_base
/ SERIAL_BAUD
) >> 8);
114 /* 8 data, 1 stop, no parity */
115 serial_outb(com_port
+ (UART_LCR
<< shift
), 0x03);
117 serial_outb(com_port
+ (UART_MCR
<< shift
), 0x03);
119 /* Clear & enable FIFOs */
120 serial_outb(com_port
+ (UART_FCR
<< shift
), 0x07);
127 serial_putc(unsigned long com_port
, unsigned char c
)
129 while ((serial_inb(com_port
+ (UART_LSR
<< shift
)) & UART_LSR_THRE
) == 0)
131 serial_outb(com_port
, c
);
135 serial_getc(unsigned long com_port
)
137 while ((serial_inb(com_port
+ (UART_LSR
<< shift
)) & UART_LSR_DR
) == 0)
139 return serial_inb(com_port
);
143 serial_tstc(unsigned long com_port
)
145 return ((serial_inb(com_port
+ (UART_LSR
<< shift
)) & UART_LSR_DR
) != 0);
149 serial_close(unsigned long com_port
)
154 gen550_init(int i
, struct uart_port
*serial_req
)
156 rs_table
[i
].io_type
= serial_req
->iotype
;
157 rs_table
[i
].port
= serial_req
->iobase
;
158 rs_table
[i
].iomem_base
= serial_req
->membase
;
159 rs_table
[i
].iomem_reg_shift
= serial_req
->regshift
;
160 rs_table
[i
].baud_base
= serial_req
->uartclk
? serial_req
->uartclk
/ 16 : BASE_BAUD
;
163 #ifdef CONFIG_SERIAL_TEXT_DEBUG
165 gen550_progress(char *s
, unsigned short hex
)
167 volatile unsigned int progress_debugport
;
170 progress_debugport
= serial_init(0, NULL
);
172 serial_putc(progress_debugport
, '\r');
174 while ((c
= *s
++) != 0)
175 serial_putc(progress_debugport
, c
);
177 serial_putc(progress_debugport
, '\n');
178 serial_putc(progress_debugport
, '\r');
180 #endif /* CONFIG_SERIAL_TEXT_DEBUG */