summaryrefslogtreecommitdiffstats
path: root/drivers/serial/serial_ks8695.c
blob: 698763b28dddb10c56bae0cdfd540d2555f4d929 (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
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
/*
 *  drivers/serial/serial_ks8695.c
 *
 *  Driver for KS8695 serial ports
 *
 *  Based on drivers/serial/serial_amba.c, by Kam Lee.
 *
 *  Copyright 2002-2005 Micrel Inc.
 *
 * 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.
 *
 */
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/serial.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/device.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/mach/irq.h>

#include <asm/arch/regs-uart.h>
#include <asm/arch/regs-irq.h>

#if defined(CONFIG_SERIAL_KS8695_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/serial_core.h>


#define SERIAL_KS8695_MAJOR	204
#define SERIAL_KS8695_MINOR	16
#define SERIAL_KS8695_DEVNAME	"ttyAM"

#define SERIAL_KS8695_NR	1

/*
 * Access macros for the KS8695 UART
 */
#define UART_GET_CHAR(p)	(__raw_readl((p)->membase + KS8695_URRB) & 0xFF)
#define UART_PUT_CHAR(p, c)	__raw_writel((c), (p)->membase + KS8695_URTH)
#define UART_GET_FCR(p)		__raw_readl((p)->membase + KS8695_URFC)
#define UART_PUT_FCR(p, c)	__raw_writel((c), (p)->membase + KS8695_URFC)
#define UART_GET_MSR(p)		__raw_readl((p)->membase + KS8695_URMS)
#define UART_GET_LSR(p)		__raw_readl((p)->membase + KS8695_URLS)
#define UART_GET_LCR(p)		__raw_readl((p)->membase + KS8695_URLC)
#define UART_PUT_LCR(p, c)	__raw_writel((c), (p)->membase + KS8695_URLC)
#define UART_GET_MCR(p)		__raw_readl((p)->membase + KS8695_URMC)
#define UART_PUT_MCR(p, c)	__raw_writel((c), (p)->membase + KS8695_URMC)
#define UART_GET_BRDR(p)	__raw_readl((p)->membase + KS8695_URBD)
#define UART_PUT_BRDR(p, c)	__raw_writel((c), (p)->membase + KS8695_URBD)

#define KS8695_CLR_TX_INT()	__raw_writel(1 << KS8695_IRQ_UART_TX, KS8695_IRQ_VA + KS8695_INTST)

#define UART_DUMMY_LSR_RX	0x100
#define UART_PORT_SIZE		(KS8695_USR - KS8695_URRB + 4)

#define tx_enabled(port) ((port)->unused[0])
#define rx_enabled(port) ((port)->unused[1])


#ifdef SUPPORT_SYSRQ
static struct console ks8695_console;
#endif

static void ks8695uart_stop_tx(struct uart_port *port)
{
	if (tx_enabled(port)) {
		disable_irq(KS8695_IRQ_UART_TX);
		tx_enabled(port) = 0;
	}
}

static void ks8695uart_start_tx(struct uart_port *port)
{
	if (!tx_enabled(port)) {
		enable_irq(KS8695_IRQ_UART_TX);
		tx_enabled(port) = 1;
	}
}

static void ks8695uart_stop_rx(struct uart_port *port)
{
	if (rx_enabled(port)) {
		disable_irq(KS8695_IRQ_UART_RX);
		rx_enabled(port) = 0;
	}
}

static void ks8695uart_enable_ms(struct uart_port *port)
{
	enable_irq(KS8695_IRQ_UART_MODEM_STATUS);
}

static void ks8695uart_disable_ms(struct uart_port *port)
{
	disable_irq(KS8695_IRQ_UART_MODEM_STATUS);
}

static irqreturn_t ks8695uart_rx_chars(int irq, void *dev_id)
{
	struct uart_port *port = dev_id;
	struct tty_struct *tty = port->info->tty;
	unsigned int status, ch, lsr, flg, max_count = 256;

	status = UART_GET_LSR(port);		/* clears pending LSR interrupts */
	while ((status & URLS_URDR) && max_count--) {
		ch = UART_GET_CHAR(port);
		flg = TTY_NORMAL;

		port->icount.rx++;

		/*
		 * Note that the error handling code is
		 * out of the main execution path
		 */
		lsr = UART_GET_LSR(port) | UART_DUMMY_LSR_RX;
		if (unlikely(lsr & (URLS_URBI | URLS_URPE | URLS_URFE | URLS_URROE))) {
			if (lsr & URLS_URBI) {
				lsr &= ~(URLS_URFE | URLS_URPE);
				port->icount.brk++;
				if (uart_handle_break(port))
					goto ignore_char;
			}
			if (lsr & URLS_URPE)
				port->icount.parity++;
			if (lsr & URLS_URFE)
				port->icount.frame++;
			if (lsr & URLS_URROE)
				port->icount.overrun++;

			lsr &= port->read_status_mask;

			if (lsr & URLS_URBI)
				flg = TTY_BREAK;
			else if (lsr & URLS_URPE)
				flg = TTY_PARITY;
			else if (lsr & URLS_URFE)
				flg = TTY_FRAME;
		}

		if (uart_handle_sysrq_char(port, ch))
			goto ignore_char;

		uart_insert_char(port, lsr, URLS_URROE, ch, flg);

ignore_char:
		status = UART_GET_LSR(port);
	}
	tty_flip_buffer_push(tty);

	return IRQ_HANDLED;
}


static irqreturn_t ks8695uart_tx_chars(int irq, void *dev_id)
{
	struct uart_port *port = dev_id;
	struct circ_buf *xmit = &port->info->xmit;
	unsigned int count;

	if (port->x_char) {
		KS8695_CLR_TX_INT();
		UART_PUT_CHAR(port, port->x_char);
		port->icount.tx++;
		port->x_char = 0;
		return IRQ_HANDLED;
	}

	if (uart_tx_stopped(port) || uart_circ_empty(xmit)) {
		ks8695uart_stop_tx(port);
		return IRQ_HANDLED;
	}

	count = 16;	/* fifo size */
	while (!uart_circ_empty(xmit) && (count-- > 0)) {
		KS8695_CLR_TX_INT();
		UART_PUT_CHAR(port, xmit->buf[xmit->tail]);

		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
		port->icount.tx++;
	}

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(port);

	if (uart_circ_empty(xmit))
		ks8695uart_stop_tx(port);

	return IRQ_HANDLED;
}

static irqreturn_t ks8695uart_modem_status(int irq, void *dev_id)
{
	struct uart_port *port = dev_id;
	unsigned int status;

	/*
	 * clear modem interrupt by reading MSR
	 */
	status = UART_GET_MSR(port);

	if (status & URMS_URDDCD)
		uart_handle_dcd_change(port, status & URMS_URDDCD);

	if (status & URMS_URDDST)
		port->icount.dsr++;

	if (status & URMS_URDCTS)
		uart_handle_cts_change(port, status & URMS_URDCTS);

	if (status & URMS_URTERI)
		port->icount.rng++;

	wake_up_interruptible(&port->info->delta_msr_wait);

	return IRQ_HANDLED;
}

static unsigned int ks8695uart_tx_empty(struct uart_port *port)
{
	return (UART_GET_LSR(port) & URLS_URTE) ? TIOCSER_TEMT : 0;
}

static unsigned int ks8695uart_get_mctrl(struct uart_port *port)
{
	unsigned int result = 0;
	unsigned int status;

	status = UART_GET_MSR(port);
	if (status & URMS_URDCD)
		result |= TIOCM_CAR;
	if (status & URMS_URDSR)
		result |= TIOCM_DSR;
	if (status & URMS_URCTS)
		result |= TIOCM_CTS;
	if (status & URMS_URRI)
		result |= TIOCM_RI;

	return result;
}

static void ks8695uart_set_mctrl(struct uart_port *port, u_int mctrl)
{
	unsigned int mcr;

	mcr = UART_GET_MCR(port);
	if (mctrl & TIOCM_RTS)
		mcr |= URMC_URRTS;
	else
		mcr &= ~URMC_URRTS;

	if (mctrl & TIOCM_DTR)
		mcr |= URMC_URDTR;
	else
		mcr &= ~URMC_URDTR;

	UART_PUT_MCR(port, mcr);
}

static void ks8695uart_break_ctl(struct uart_port *port, int break_state)
{
	unsigned int lcr;

	lcr = UART_GET_LCR(port);

	if (break_state == -1)
		lcr |= URLC_URSBC;
	else
		lcr &= ~URLC_URSBC;

	UART_PUT_LCR(port, lcr);
}

static int ks8695uart_startup(struct uart_port *port)
{
	int retval;

	set_irq_flags(KS8695_IRQ_UART_TX, IRQF_VALID | IRQF_NOAUTOEN);
	tx_enabled(port) = 0;
	rx_enabled(port) = 1;

	/*
	 * Allocate the IRQ
	 */
	retval = request_irq(KS8695_IRQ_UART_TX, ks8695uart_tx_chars, IRQF_DISABLED, "UART TX", port);
	if (retval)
		goto err_tx;

	retval = request_irq(KS8695_IRQ_UART_RX, ks8695uart_rx_chars, IRQF_DISABLED, "UART RX", port);
	if (retval)
		goto err_rx;

	retval = request_irq(KS8695_IRQ_UART_LINE_STATUS, ks8695uart_rx_chars, IRQF_DISABLED, "UART LineStatus", port);
	if (retval)
		goto err_ls;

	retval = request_irq(KS8695_IRQ_UART_MODEM_STATUS, ks8695uart_modem_status, IRQF_DISABLED, "UART ModemStatus", port);
	if (retval)
		goto err_ms;

	return 0;

err_ms:
	free_irq(KS8695_IRQ_UART_LINE_STATUS, port);
err_ls:
	free_irq(KS8695_IRQ_UART_RX, port);
err_rx:
	free_irq(KS8695_IRQ_UART_TX, port);
err_tx:
	return retval;
}

static void ks8695uart_shutdown(struct uart_port *port)
{
	/*
	 * Free the interrupt
	 */
	free_irq(KS8695_IRQ_UART_RX, port);
	free_irq(KS8695_IRQ_UART_TX, port);
	free_irq(KS8695_IRQ_UART_MODEM_STATUS, port);
	free_irq(KS8695_IRQ_UART_LINE_STATUS, port);

	/* disable break condition and fifos */
	UART_PUT_LCR(port, UART_GET_LCR(port) & ~URLC_URSBC);
	UART_PUT_FCR(port, UART_GET_FCR(port) & ~URFC_URFE);
}

static void ks8695uart_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old)
{
	unsigned int lcr, fcr = 0;
	unsigned long flags;
	unsigned int baud, quot;

	/*
	 * Ask the core to calculate the divisor for us.
	 */
	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
	quot = uart_get_divisor(port, baud);

	switch (termios->c_cflag & CSIZE) {
	case CS5:
		lcr = URCL_5;
		break;
	case CS6:
		lcr = URCL_6;
		break;
	case CS7:
		lcr = URCL_7;
		break;
	default:
		lcr = URCL_8;
		break;
	}

	/* stop bits */
	if (termios->c_cflag & CSTOPB)
		lcr |= URLC_URSB;

	/* parity */
	if (termios->c_cflag & PARENB) {
		if (termios->c_cflag & CMSPAR) {	/* Mark or Space parity */
			if (termios->c_cflag & PARODD)
				lcr |= URPE_MARK;
			else
				lcr |= URPE_SPACE;
		}
		else if (termios->c_cflag & PARODD)
			lcr |= URPE_ODD;
		else
			lcr |= URPE_EVEN;
	}

	if (port->fifosize > 1)
		fcr = URFC_URFRT_8 | URFC_URTFR | URFC_URRFR | URFC_URFE;

	spin_lock_irqsave(&port->lock, flags);

	/*
	 * Update the per-port timeout.
	 */
	uart_update_timeout(port, termios->c_cflag, baud);

	port->read_status_mask = URLS_URROE;
	if (termios->c_iflag & INPCK)
		port->read_status_mask |= (URLS_URFE | URLS_URPE);
	if (termios->c_iflag & (BRKINT | PARMRK))
		port->read_status_mask |= URLS_URBI;

	/*
	 * Characters to ignore
	 */
	port->ignore_status_mask = 0;
	if (termios->c_iflag & IGNPAR)
		port->ignore_status_mask |= (URLS_URFE | URLS_URPE);
	if (termios->c_iflag & IGNBRK) {
		port->ignore_status_mask |= URLS_URBI;
		/*
		 * If we're ignoring parity and break indicators,
		 * ignore overruns too (for real raw support).
		 */
		if (termios->c_iflag & IGNPAR)
			port->ignore_status_mask |= URLS_URROE;
	}

	/*
	 * Ignore all characters if CREAD is not set.
	 */
	if ((termios->c_cflag & CREAD) == 0)
		port->ignore_status_mask |= UART_DUMMY_LSR_RX;

	/* first, disable everything */
	if (UART_ENABLE_MS(port, termios->c_cflag))
		ks8695uart_enable_ms(port);
	else
		ks8695uart_disable_ms(port);

	/* Set baud rate */
	UART_PUT_BRDR(port, quot);

	UART_PUT_LCR(port, lcr);
	UART_PUT_FCR(port, fcr);

	spin_unlock_irqrestore(&port->lock, flags);
}

static const char *ks8695uart_type(struct uart_port *port)
{
	return port->type == PORT_KS8695 ? "KS8695" : NULL;
}

/*
 * Release the memory region(s) being used by 'port'
 */
static void ks8695uart_release_port(struct uart_port *port)
{
	release_mem_region(port->mapbase, UART_PORT_SIZE);
}

/*
 * Request the memory region(s) being used by 'port'
 */
static int ks8695uart_request_port(struct uart_port *port)
{
	return request_mem_region(port->mapbase, UART_PORT_SIZE,
			"serial_ks8695") != NULL ? 0 : -EBUSY;
}

/*
 * Configure/autoconfigure the port.
 */
static void ks8695uart_config_port(struct uart_port *port, int flags)
{
	if (flags & UART_CONFIG_TYPE) {
		port->type = PORT_KS8695;
		ks8695uart_request_port(port);
	}
}

/*
 * verify the new serial_struct (for TIOCSSERIAL).
 */
static int ks8695uart_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	int ret = 0;

	if (ser->type != PORT_UNKNOWN && ser->type != PORT_KS8695)
		ret = -EINVAL;
	if (ser->irq != port->irq)
		ret = -EINVAL;
	if (ser->baud_base < 9600)
		ret = -EINVAL;
	return ret;
}

static struct uart_ops ks8695uart_pops = {
	.tx_empty	= ks8695uart_tx_empty,
	.set_mctrl	= ks8695uart_set_mctrl,
	.get_mctrl	= ks8695uart_get_mctrl,
	.stop_tx	= ks8695uart_stop_tx,
	.start_tx	= ks8695uart_start_tx,
	.stop_rx	= ks8695uart_stop_rx,
	.enable_ms	= ks8695uart_enable_ms,
	.break_ctl	= ks8695uart_break_ctl,
	.startup	= ks8695uart_startup,
	.shutdown	= ks8695uart_shutdown,
	.set_termios	= ks8695uart_set_termios,
	.type		= ks8695uart_type,
	.release_port	= ks8695uart_release_port,
	.request_port	= ks8695uart_request_port,
	.config_port	= ks8695uart_config_port,
	.verify_port	= ks8695uart_verify_port,
};

static struct uart_port ks8695uart_ports[SERIAL_KS8695_NR] = {
	{
		.membase	= (void *) KS8695_UART_VA,
		.mapbase	= KS8695_UART_VA,
		.iotype		= SERIAL_IO_MEM,
		.irq		= KS8695_IRQ_UART_TX,
		.uartclk	= CLOCK_TICK_RATE * 16,
		.fifosize	= 16,
		.ops		= &ks8695uart_pops,
		.flags		= ASYNC_BOOT_AUTOCONF,
		.line		= 0,
	}
};

#ifdef CONFIG_SERIAL_KS8695_CONSOLE
static void ks8695_console_putchar(struct uart_port *port, int ch)
{
	while (!(UART_GET_LSR(port) & URLS_URTHRE))
		barrier();

	UART_PUT_CHAR(port, ch);
}

static void ks8695_console_write(struct console *co, const char *s, u_int count)
{
	struct uart_port *port = ks8695uart_ports + co->index;

	uart_console_write(port, s, count, ks8695_console_putchar);
}

static void __init ks8695_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)
{
	unsigned int lcr;

	lcr = UART_GET_LCR(port);

	switch (lcr & URLC_PARITY) {
		case URPE_ODD:
			*parity = 'o';
			break;
		case URPE_EVEN:
			*parity = 'e';
			break;
		default:
			*parity = 'n';
	}

	switch (lcr & URLC_URCL) {
		case URCL_5:
			*bits = 5;
			break;
		case URCL_6:
			*bits = 6;
			break;
		case URCL_7:
			*bits = 7;
			break;
		default:
			*bits = 8;
	}

	*baud = port->uartclk / (UART_GET_BRDR(port) & 0x0FFF);
	*baud /= 16;
	*baud &= 0xFFFFFFF0;
}

static int __init ks8695_console_setup(struct console *co, char *options)
{
	struct uart_port *port;
	int baud = 115200;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

	/*
	 * Check whether an invalid uart number has been specified, and
	 * if so, search for the first available port that does have
	 * console support.
	 */
	port = uart_get_console(ks8695uart_ports, SERIAL_KS8695_NR, co);

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);
	else
		ks8695_console_get_options(port, &baud, &parity, &bits);

	return uart_set_options(port, co, baud, parity, bits, flow);
}

extern struct uart_driver ks8695_reg;

static struct console ks8695_console = {
	.name		= SERIAL_KS8695_DEVNAME,
	.write		= ks8695_console_write,
	.device		= uart_console_device,
	.setup		= ks8695_console_setup,
	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &ks8695_reg,
};

static int __init ks8695_console_init(void)
{
	register_console(&ks8695_console);
	return 0;
}

console_initcall(ks8695_console_init);

#define KS8695_CONSOLE	&ks8695_console
#else
#define KS8695_CONSOLE	NULL
#endif

static struct uart_driver ks8695_reg = {
	.owner			= THIS_MODULE,
	.driver_name		= "serial_ks8695",
	.dev_name		= SERIAL_KS8695_DEVNAME,
	.major			= SERIAL_KS8695_MAJOR,
	.minor			= SERIAL_KS8695_MINOR,
	.nr			= SERIAL_KS8695_NR,
	.cons			= KS8695_CONSOLE,
};

static int __init ks8695uart_init(void)
{
	int i, ret;

	printk(KERN_INFO "Serial: Micrel KS8695 UART driver\n");

	ret = uart_register_driver(&ks8695_reg);
	if (ret)
		return ret;

	for (i = 0; i < SERIAL_KS8695_NR; i++)
		uart_add_one_port(&ks8695_reg, &ks8695uart_ports[0]);

	return 0;
}

static void __exit ks8695uart_exit(void)
{
	int i;

	for (i = 0; i < SERIAL_KS8695_NR; i++)
		uart_remove_one_port(&ks8695_reg, &ks8695uart_ports[0]);
	uart_unregister_driver(&ks8695_reg);
}

module_init(ks8695uart_init);
module_exit(ks8695uart_exit);

MODULE_DESCRIPTION("KS8695 serial port driver");
MODULE_AUTHOR("Micrel Inc.");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud