summaryrefslogtreecommitdiff
path: root/cpu/i386/serial.c
blob: e7025a3cdc051a51bf38c3a9418620ec598c4542 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
/*
 * (C) Copyright 2002
 * Daniel Engström, Omicron Ceti AB, daniel@omicron.se
 *
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */
/*------------------------------------------------------------------------------+ */

/*
 * This source code is dual-licensed.  You may use it under the terms of the
 * GNU General Public License version 2, or under the license below.
 *
 * This source code has been made available to you by IBM on an AS-IS
 * basis.  Anyone receiving this source is licensed under IBM
 * copyrights to use it in any way he or she deems fit, including
 * copying it, modifying it, compiling it, and redistributing it either
 * with or without modifications.  No license under IBM patents or
 * patent applications is to be implied by the copyright license.
 *
 * Any user of this software should understand that IBM cannot provide
 * technical support for this software and will not be responsible for
 * any consequences resulting from the use of this software.
 *
 * Any person who transfers this source code or any derivative work
 * must include the IBM copyright notice, this paragraph, and the
 * preceding two paragraphs in the transferred software.
 *
 * COPYRIGHT   I B M   CORPORATION 1995
 * LICENSED MATERIAL  -  PROGRAM PROPERTY OF I B M
 */
/*------------------------------------------------------------------------------- */

#include <common.h>
#include <watchdog.h>
#include <asm/io.h>
#include <asm/ibmpc.h>

#ifdef CONFIG_SERIAL_SOFTWARE_FIFO
#include <malloc.h>
#endif

DECLARE_GLOBAL_DATA_PTR;

#define UART_RBR    0x00
#define UART_THR    0x00
#define UART_IER    0x01
#define UART_IIR    0x02
#define UART_FCR    0x02
#define UART_LCR    0x03
#define UART_MCR    0x04
#define UART_LSR    0x05
#define UART_MSR    0x06
#define UART_SCR    0x07
#define UART_DLL    0x00
#define UART_DLM    0x01

/*-----------------------------------------------------------------------------+
  | Line Status Register.
  +-----------------------------------------------------------------------------*/
#define asyncLSRDataReady1            0x01
#define asyncLSROverrunError1         0x02
#define asyncLSRParityError1          0x04
#define asyncLSRFramingError1         0x08
#define asyncLSRBreakInterrupt1       0x10
#define asyncLSRTxHoldEmpty1          0x20
#define asyncLSRTxShiftEmpty1         0x40
#define asyncLSRRxFifoError1          0x80


#ifdef CONFIG_SERIAL_SOFTWARE_FIFO
/*-----------------------------------------------------------------------------+
  | Fifo
  +-----------------------------------------------------------------------------*/
typedef struct {
	char *rx_buffer;
	ulong rx_put;
	ulong rx_get;
	int cts;
} serial_buffer_t;

volatile serial_buffer_t buf_info;
static int serial_buffer_active=0;
#endif


static int serial_div(int baudrate)
{

	switch (baudrate) {
	case 1200:
		return 96;
	case 9600:
		return 12;
	case 19200:
		return 6;
	case 38400:
		return 3;
	case 57600:
		return 2;
	case 115200:
		return 1;
	}

	return 12;
}


/*
 * Minimal serial functions needed to use one of the SMC ports
 * as serial console interface.
 */

int serial_init(void)
{
	volatile char val;
	int bdiv = serial_div(gd->baudrate);

	outb(0x80, UART0_BASE + UART_LCR);	/* set DLAB bit */
	outb(bdiv, UART0_BASE + UART_DLL);	/* set baudrate divisor */
	outb(bdiv >> 8, UART0_BASE + UART_DLM);/* set baudrate divisor */
	outb(0x03, UART0_BASE + UART_LCR);	/* clear DLAB; set 8 bits, no parity */
	outb(0x01, UART0_BASE + UART_FCR);	/* enable FIFO */
	outb(0x0b, UART0_BASE + UART_MCR);	/* Set DTR and RTS active */
	val = inb(UART0_BASE + UART_LSR);	/* clear line status */
	val = inb(UART0_BASE + UART_RBR);	/* read receive buffer */
	outb(0x00, UART0_BASE + UART_SCR);	/* set scratchpad */
	outb(0x00, UART0_BASE + UART_IER);	/* set interrupt enable reg */

	return 0;
}


void serial_setbrg(void)
{
	unsigned short bdiv;

	bdiv = serial_div(gd->baudrate);

	outb(0x80, UART0_BASE + UART_LCR);	/* set DLAB bit */
	outb(bdiv&0xff, UART0_BASE + UART_DLL);	/* set baudrate divisor */
	outb(bdiv >> 8, UART0_BASE + UART_DLM);/* set baudrate divisor */
	outb(0x03, UART0_BASE + UART_LCR);	/* clear DLAB; set 8 bits, no parity */
}


void serial_putc(const char c)
{
	int i;

	if (c == '\n')
		serial_putc ('\r');

	/* check THRE bit, wait for transmiter available */
	for (i = 1; i < 3500; i++) {
		if ((inb (UART0_BASE + UART_LSR) & 0x20) == 0x20) {
			break;
		}
		udelay(100);
	}
	outb(c, UART0_BASE + UART_THR);	/* put character out */
}


void serial_puts(const char *s)
{
	while (*s) {
		serial_putc(*s++);
	}
}


int serial_getc(void)
{
	unsigned char status = 0;

#ifdef CONFIG_SERIAL_SOFTWARE_FIFO
	if (serial_buffer_active) {
		return serial_buffered_getc();
	}
#endif

	while (1) {
#if defined(CONFIG_HW_WATCHDOG)
		WATCHDOG_RESET();	/* Reset HW Watchdog, if needed */
#endif	/* CONFIG_HW_WATCHDOG */
		status = inb(UART0_BASE + UART_LSR);
		if ((status & asyncLSRDataReady1) != 0x0) {
			break;
		}
		if ((status & ( asyncLSRFramingError1 |
				asyncLSROverrunError1 |
				asyncLSRParityError1  |
				asyncLSRBreakInterrupt1 )) != 0) {
			outb(asyncLSRFramingError1 |
			      asyncLSROverrunError1 |
			      asyncLSRParityError1  |
			      asyncLSRBreakInterrupt1, UART0_BASE + UART_LSR);
		}
	}
	return (0x000000ff & (int) inb (UART0_BASE));
}


int serial_tstc(void)
{
	unsigned char status;

#ifdef CONFIG_SERIAL_SOFTWARE_FIFO
	if (serial_buffer_active) {
		return serial_buffered_tstc();
	}
#endif

	status = inb(UART0_BASE + UART_LSR);
	if ((status & asyncLSRDataReady1) != 0x0) {
		return (1);
	}
	if ((status & ( asyncLSRFramingError1 |
			asyncLSROverrunError1 |
			asyncLSRParityError1  |
			asyncLSRBreakInterrupt1 )) != 0) {
		outb(asyncLSRFramingError1 |
		      asyncLSROverrunError1 |
		      asyncLSRParityError1  |
		      asyncLSRBreakInterrupt1, UART0_BASE + UART_LSR);
	}
	return 0;
}


#ifdef CONFIG_SERIAL_SOFTWARE_FIFO

void serial_isr(void *arg)
{
	int space;
	int c;
	int rx_put = buf_info.rx_put;

	if (buf_info.rx_get <= rx_put) {
		space = CONFIG_SERIAL_SOFTWARE_FIFO - (rx_put - buf_info.rx_get);
	} else {
		space = buf_info.rx_get - rx_put;
	}

	while (inb(UART0_BASE + UART_LSR) & 1) {
		c = inb(UART0_BASE);
		if (space) {
			buf_info.rx_buffer[rx_put++] = c;
			space--;

			if (rx_put == buf_info.rx_get) {
				buf_info.rx_get++;
				if (rx_put == CONFIG_SERIAL_SOFTWARE_FIFO) {
					buf_info.rx_get = 0;
				}
			}

			if (rx_put == CONFIG_SERIAL_SOFTWARE_FIFO) {
				rx_put = 0;
				if (0 == buf_info.rx_get) {
					buf_info.rx_get = 1;
				}

			}

		}
		if (space < CONFIG_SERIAL_SOFTWARE_FIFO / 4) {
			/* Stop flow by setting RTS inactive */
			outb(inb(UART0_BASE + UART_MCR) & (0xFF ^ 0x02),
			      UART0_BASE + UART_MCR);
		}
	}
	buf_info.rx_put = rx_put;
}

void serial_buffered_init(void)
{
	serial_puts ("Switching to interrupt driven serial input mode.\n");
	buf_info.rx_buffer = malloc (CONFIG_SERIAL_SOFTWARE_FIFO);
	buf_info.rx_put = 0;
	buf_info.rx_get = 0;

	if (inb (UART0_BASE + UART_MSR) & 0x10) {
		serial_puts ("Check CTS signal present on serial port: OK.\n");
		buf_info.cts = 1;
	} else {
		serial_puts ("WARNING: CTS signal not present on serial port.\n");
		buf_info.cts = 0;
	}

	irq_install_handler ( VECNUM_U0 /*UART0 */ /*int vec */ ,
			      serial_isr /*interrupt_handler_t *handler */ ,
			      (void *) &buf_info /*void *arg */ );

	/* Enable "RX Data Available" Interrupt on UART */
	/* outb(inb(UART0_BASE + UART_IER) |0x01, UART0_BASE + UART_IER); */
	outb(0x01, UART0_BASE + UART_IER);

	/* Set DTR and RTS active, enable interrupts  */
	outb(inb (UART0_BASE + UART_MCR) | 0x0b, UART0_BASE + UART_MCR);

	/* Setup UART FIFO: RX trigger level: 1 byte, Enable FIFO */
	outb( /*(1 << 6) |*/  1, UART0_BASE + UART_FCR);

	serial_buffer_active = 1;
}

void serial_buffered_putc (const char c)
{
	int i;
	/* Wait for CTS */
#if defined(CONFIG_HW_WATCHDOG)
	while (!(inb (UART0_BASE + UART_MSR) & 0x10))
		WATCHDOG_RESET ();
#else
	if (buf_info.cts)  {
		for (i=0;i<1000;i++) {
			if ((inb (UART0_BASE + UART_MSR) & 0x10)) {
				break;
			}
		}
		if (i!=1000) {
			buf_info.cts = 0;
		}
	} else {
		if ((inb (UART0_BASE + UART_MSR) & 0x10)) {
			buf_info.cts = 1;
		}
	}

#endif
	serial_putc (c);
}

void serial_buffered_puts(const char *s)
{
	serial_puts (s);
}

int serial_buffered_getc(void)
{
	int space;
	int c;
	int rx_get = buf_info.rx_get;
	int rx_put;

#if defined(CONFIG_HW_WATCHDOG)
	while (rx_get == buf_info.rx_put)
		WATCHDOG_RESET ();
#else
	while (rx_get == buf_info.rx_put);
#endif
	c = buf_info.rx_buffer[rx_get++];
	if (rx_get == CONFIG_SERIAL_SOFTWARE_FIFO) {
		rx_get = 0;
	}
	buf_info.rx_get = rx_get;

	rx_put = buf_info.rx_put;
	if (rx_get <= rx_put) {
		space = CONFIG_SERIAL_SOFTWARE_FIFO - (rx_put - rx_get);
	} else {
		space = rx_get - rx_put;
	}
	if (space > CONFIG_SERIAL_SOFTWARE_FIFO / 2) {
		/* Start flow by setting RTS active */
		outb(inb (UART0_BASE + UART_MCR) | 0x02, UART0_BASE + UART_MCR);
	}

	return c;
}

int serial_buffered_tstc(void)
{
	return (buf_info.rx_get != buf_info.rx_put) ? 1 : 0;
}

#endif	/* CONFIG_SERIAL_SOFTWARE_FIFO */


#if defined(CONFIG_CMD_KGDB)
/*
  AS HARNOIS : according to CONFIG_KGDB_SER_INDEX kgdb uses serial port
  number 0 or number 1
  - if CONFIG_KGDB_SER_INDEX = 1 => serial port number 0 :
  configuration has been already done
  - if CONFIG_KGDB_SER_INDEX = 2 => serial port number 1 :
  configure port 1 for serial I/O with rate = CONFIG_KGDB_BAUDRATE
*/
#if (CONFIG_KGDB_SER_INDEX & 2)
void kgdb_serial_init(void)
{
	volatile char val;
	bdiv = serial_div (CONFIG_KGDB_BAUDRATE);

	/*
	 * Init onboard 16550 UART
	 */
	outb(0x80, UART1_BASE + UART_LCR);	/* set DLAB bit */
	outb((bdiv & 0xff), UART1_BASE + UART_DLL);	/* set divisor for 9600 baud */
	outb((bdiv >> 8  ), UART1_BASE + UART_DLM);	/* set divisor for 9600 baud */
	outb(0x03, UART1_BASE + UART_LCR);	/* line control 8 bits no parity */
	outb(0x00, UART1_BASE + UART_FCR);	/* disable FIFO */
	outb(0x00, UART1_BASE + UART_MCR);	/* no modem control DTR RTS */
	val = inb(UART1_BASE + UART_LSR);	/* clear line status */
	val = inb(UART1_BASE + UART_RBR);	/* read receive buffer */
	outb(0x00, UART1_BASE + UART_SCR);	/* set scratchpad */
	outb(0x00, UART1_BASE + UART_IER);	/* set interrupt enable reg */
}


void putDebugChar(const char c)
{
	if (c == '\n')
		serial_putc ('\r');

	outb(c, UART1_BASE + UART_THR);	/* put character out */

	/* check THRE bit, wait for transfer done */
	while ((inb(UART1_BASE + UART_LSR) & 0x20) != 0x20);
}


void putDebugStr(const char *s)
{
	while (*s) {
		serial_putc(*s++);
	}
}


int getDebugChar(void)
{
	unsigned char status = 0;

	while (1) {
		status = inb(UART1_BASE + UART_LSR);
		if ((status & asyncLSRDataReady1) != 0x0) {
			break;
		}
		if ((status & ( asyncLSRFramingError1 |
				asyncLSROverrunError1 |
				asyncLSRParityError1  |
				asyncLSRBreakInterrupt1 )) != 0) {
			outb(asyncLSRFramingError1 |
			     asyncLSROverrunError1 |
			     asyncLSRParityError1  |
			     asyncLSRBreakInterrupt1, UART1_BASE + UART_LSR);
		}
	}
	return (0x000000ff & (int) inb(UART1_BASE));
}


void kgdb_interruptible(int yes)
{
	return;
}

#else	/* ! (CONFIG_KGDB_SER_INDEX & 2) */

void kgdb_serial_init(void)
{
	serial_printf ("[on serial] ");
}

void putDebugChar(int c)
{
	serial_putc (c);
}

void putDebugStr(const char *str)
{
	serial_puts (str);
}

int getDebugChar(void)
{
	return serial_getc ();
}

void kgdb_interruptible(int yes)
{
	return;
}
#endif	/* (CONFIG_KGDB_SER_INDEX & 2) */
#endif