1 /*
2 * drivers/serial/netx-serial.c
3 *
4 * Copyright (c) 2005 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #if defined(CONFIG_SERIAL_NETX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
21 #define SUPPORT_SYSRQ
22 #endif
23
24 #include <linux/device.h>
25 #include <linux/module.h>
26 #include <linux/ioport.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
29 #include <linux/sysrq.h>
30 #include <linux/platform_device.h>
31 #include <linux/tty.h>
32 #include <linux/tty_flip.h>
33 #include <linux/serial_core.h>
34 #include <linux/serial.h>
35
36 #include <asm/io.h>
37 #include <asm/irq.h>
38 #include <mach/hardware.h>
39 #include <mach/netx-regs.h>
40
41 /* We've been assigned a range on the "Low-density serial ports" major */
42 #define SERIAL_NX_MAJOR 204
43 #define MINOR_START 170
44
45 enum uart_regs {
46 UART_DR = 0x00,
47 UART_SR = 0x04,
48 UART_LINE_CR = 0x08,
49 UART_BAUDDIV_MSB = 0x0c,
50 UART_BAUDDIV_LSB = 0x10,
51 UART_CR = 0x14,
52 UART_FR = 0x18,
53 UART_IIR = 0x1c,
54 UART_ILPR = 0x20,
55 UART_RTS_CR = 0x24,
56 UART_RTS_LEAD = 0x28,
57 UART_RTS_TRAIL = 0x2c,
58 UART_DRV_ENABLE = 0x30,
59 UART_BRM_CR = 0x34,
60 UART_RXFIFO_IRQLEVEL = 0x38,
61 UART_TXFIFO_IRQLEVEL = 0x3c,
62 };
63
64 #define SR_FE (1<<0)
65 #define SR_PE (1<<1)
66 #define SR_BE (1<<2)
67 #define SR_OE (1<<3)
68
69 #define LINE_CR_BRK (1<<0)
70 #define LINE_CR_PEN (1<<1)
71 #define LINE_CR_EPS (1<<2)
72 #define LINE_CR_STP2 (1<<3)
73 #define LINE_CR_FEN (1<<4)
74 #define LINE_CR_5BIT (0<<5)
75 #define LINE_CR_6BIT (1<<5)
76 #define LINE_CR_7BIT (2<<5)
77 #define LINE_CR_8BIT (3<<5)
78 #define LINE_CR_BITS_MASK (3<<5)
79
80 #define CR_UART_EN (1<<0)
81 #define CR_SIREN (1<<1)
82 #define CR_SIRLP (1<<2)
83 #define CR_MSIE (1<<3)
84 #define CR_RIE (1<<4)
85 #define CR_TIE (1<<5)
86 #define CR_RTIE (1<<6)
87 #define CR_LBE (1<<7)
88
89 #define FR_CTS (1<<0)
90 #define FR_DSR (1<<1)
91 #define FR_DCD (1<<2)
92 #define FR_BUSY (1<<3)
93 #define FR_RXFE (1<<4)
94 #define FR_TXFF (1<<5)
95 #define FR_RXFF (1<<6)
96 #define FR_TXFE (1<<7)
97
98 #define IIR_MIS (1<<0)
99 #define IIR_RIS (1<<1)
100 #define IIR_TIS (1<<2)
101 #define IIR_RTIS (1<<3)
102 #define IIR_MASK 0xf
103
104 #define RTS_CR_AUTO (1<<0)
105 #define RTS_CR_RTS (1<<1)
106 #define RTS_CR_COUNT (1<<2)
107 #define RTS_CR_MOD2 (1<<3)
108 #define RTS_CR_RTS_POL (1<<4)
109 #define RTS_CR_CTS_CTR (1<<5)
110 #define RTS_CR_CTS_POL (1<<6)
111 #define RTS_CR_STICK (1<<7)
112
113 #define UART_PORT_SIZE 0x40
114 #define DRIVER_NAME "netx-uart"
115
116 struct netx_port {
117 struct uart_port port;
118 };
119
120 static void netx_stop_tx(struct uart_port *port)
121 {
122 unsigned int val;
123 val = readl(port->membase + UART_CR);
124 writel(val & ~CR_TIE, port->membase + UART_CR);
125 }
126
127 static void netx_stop_rx(struct uart_port *port)
128 {
129 unsigned int val;
130 val = readl(port->membase + UART_CR);
131 writel(val & ~CR_RIE, port->membase + UART_CR);
132 }
133
134 static void netx_enable_ms(struct uart_port *port)
135 {
136 unsigned int val;
137 val = readl(port->membase + UART_CR);
138 writel(val | CR_MSIE, port->membase + UART_CR);
139 }
140
141 static inline void netx_transmit_buffer(struct uart_port *port)
142 {
143 struct circ_buf *xmit = &port->info->xmit;
144
145 if (port->x_char) {
146 writel(port->x_char, port->membase + UART_DR);
147 port->icount.tx++;
148 port->x_char = 0;
149 return;
150 }
151
152 if (uart_tx_stopped(port) || uart_circ_empty(xmit)) {
153 netx_stop_tx(port);
154 return;
155 }
156
157 do {
158 /* send xmit->buf[xmit->tail]
159 * out the port here */
160 writel(xmit->buf[xmit->tail], port->membase + UART_DR);
161 xmit->tail = (xmit->tail + 1) &
162 (UART_XMIT_SIZE - 1);
163 port->icount.tx++;
164 if (uart_circ_empty(xmit))
165 break;
166 } while (!(readl(port->membase + UART_FR) & FR_TXFF));
167
168 if (uart_circ_empty(xmit))
169 netx_stop_tx(port);
170 }
171
172 static void netx_start_tx(struct uart_port *port)
173 {
174 writel(
175 readl(port->membase + UART_CR) | CR_TIE, port->membase + UART_CR);
176
177 if (!(readl(port->membase + UART_FR) & FR_TXFF))
178 netx_transmit_buffer(port);
179 }
180
181 static unsigned int netx_tx_empty(struct uart_port *port)
182 {
183 return readl(port->membase + UART_FR) & FR_BUSY ? 0 : TIOCSER_TEMT;
184 }
185
186 static void netx_txint(struct uart_port *port)
187 {
188 struct circ_buf *xmit = &port->info->xmit;
189
190 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
191 netx_stop_tx(port);
192 return;
193 }
194
195 netx_transmit_buffer(port);
196
197 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
198 uart_write_wakeup(port);
199 }
200
201 static void netx_rxint(struct uart_port *port)
202 {
203 unsigned char rx, flg, status;
204 struct tty_struct *tty = port->info->port.tty;
205
206 while (!(readl(port->membase + UART_FR) & FR_RXFE)) {
207 rx = readl(port->membase + UART_DR);
208 flg = TTY_NORMAL;
209 port->icount.rx++;
210 status = readl(port->membase + UART_SR);
211 if (status & SR_BE) {
212 writel(0, port->membase + UART_SR);
213 if (uart_handle_break(port))
214 continue;
215 }
216
217 if (unlikely(status & (SR_FE | SR_PE | SR_OE))) {
218
219 if (status & SR_PE)
220 port->icount.parity++;
221 else if (status & SR_FE)
222 port->icount.frame++;
223 if (status & SR_OE)
224 port->icount.overrun++;
225
226 status &= port->read_status_mask;
227
228 if (status & SR_BE)
229 flg = TTY_BREAK;
230 else if (status & SR_PE)
231 flg = TTY_PARITY;
232 else if (status & SR_FE)
233 flg = TTY_FRAME;
234 }
235
236 if (uart_handle_sysrq_char(port, rx))
237 continue;
238
239 uart_insert_char(port, status, SR_OE, rx, flg);
240 }
241
242 tty_flip_buffer_push(tty);
243 return;
244 }
245
246 static irqreturn_t netx_int(int irq, void *dev_id)
247 {
248 struct uart_port *port = dev_id;
249 unsigned long flags;
250 unsigned char status;
251
252 spin_lock_irqsave(&port->lock,flags);
253
254 status = readl(port->membase + UART_IIR) & IIR_MASK;
255 while (status) {
256 if (status & IIR_RIS)
257 netx_rxint(port);
258 if (status & IIR_TIS)
259 netx_txint(port);
260 if (status & IIR_MIS) {
261 if (readl(port->membase + UART_FR) & FR_CTS)
262 uart_handle_cts_change(port, 1);
263 else
264 uart_handle_cts_change(port, 0);
265 }
266 writel(0, port->membase + UART_IIR);
267 status = readl(port->membase + UART_IIR) & IIR_MASK;
268 }
269
270 spin_unlock_irqrestore(&port->lock,flags);
271 return IRQ_HANDLED;
272 }
273
274 static unsigned int netx_get_mctrl(struct uart_port *port)
275 {
276 unsigned int ret = TIOCM_DSR | TIOCM_CAR;
277
278 if (readl(port->membase + UART_FR) & FR_CTS)
279 ret |= TIOCM_CTS;
280
281 return ret;
282 }
283
284 static void netx_set_mctrl(struct uart_port *port, unsigned int mctrl)
285 {
286 unsigned int val;
287
288 /* FIXME: Locking needed ? */
289 if (mctrl & TIOCM_RTS) {
290 val = readl(port->membase + UART_RTS_CR);
291 writel(val | RTS_CR_RTS, port->membase + UART_RTS_CR);
292 }
293 }
294
295 static void netx_break_ctl(struct uart_port *port, int break_state)
296 {
297 unsigned int line_cr;
298 spin_lock_irq(&port->lock);
299
300 line_cr = readl(port->membase + UART_LINE_CR);
301 if (break_state != 0)
302 line_cr |= LINE_CR_BRK;
303 else
304 line_cr &= ~LINE_CR_BRK;
305 writel(line_cr, port->membase + UART_LINE_CR);
306
307 spin_unlock_irq(&port->lock);
308 }
309
310 static int netx_startup(struct uart_port *port)
311 {
312 int ret;
313
314 ret = request_irq(port->irq, netx_int, 0,
315 DRIVER_NAME, port);
316 if (ret) {
317 dev_err(port->dev, "unable to grab irq%d\n",port->irq);
318 goto exit;
319 }
320
321 writel(readl(port->membase + UART_LINE_CR) | LINE_CR_FEN,
322 port->membase + UART_LINE_CR);
323
324 writel(CR_MSIE | CR_RIE | CR_TIE | CR_RTIE | CR_UART_EN,
325 port->membase + UART_CR);
326
327 exit:
328 return ret;
329 }
330
331 static void netx_shutdown(struct uart_port *port)
332 {
333 writel(0, port->membase + UART_CR) ;
334
335 free_irq(port->irq, port);
336 }
337
338 static void
339 netx_set_termios(struct uart_port *port, struct ktermios *termios,
340 struct ktermios *old)
341 {
342 unsigned int baud, quot;
343 unsigned char old_cr;
344 unsigned char line_cr = LINE_CR_FEN;
345 unsigned char rts_cr = 0;
346
347 switch (termios->c_cflag & CSIZE) {
348 case CS5:
349 line_cr |= LINE_CR_5BIT;
350 break;
351 case CS6:
352 line_cr |= LINE_CR_6BIT;
353 break;
354 case CS7:
355 line_cr |= LINE_CR_7BIT;
356 break;
357 case CS8:
358 line_cr |= LINE_CR_8BIT;
359 break;
360 }
361
362 if (termios->c_cflag & CSTOPB)
363 line_cr |= LINE_CR_STP2;
364
365 if (termios->c_cflag & PARENB) {
366 line_cr |= LINE_CR_PEN;
367 if (!(termios->c_cflag & PARODD))
368 line_cr |= LINE_CR_EPS;
369 }
370
371 if (termios->c_cflag & CRTSCTS)
372 rts_cr = RTS_CR_AUTO | RTS_CR_CTS_CTR | RTS_CR_RTS_POL;
373
374 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
375 quot = baud * 4096;
376 quot /= 1000;
377 quot *= 256;
378 quot /= 100000;
379
380 spin_lock_irq(&port->lock);
381
382 uart_update_timeout(port, termios->c_cflag, baud);
383
384 old_cr = readl(port->membase + UART_CR);
385
386 /* disable interrupts */
387 writel(old_cr & ~(CR_MSIE | CR_RIE | CR_TIE | CR_RTIE),
388 port->membase + UART_CR);
389
390 /* drain transmitter */
391 while (readl(port->membase + UART_FR) & FR_BUSY);
392
393 /* disable UART */
394 writel(old_cr & ~CR_UART_EN, port->membase + UART_CR);
395
396 /* modem status interrupts */
397 old_cr &= ~CR_MSIE;
398 if (UART_ENABLE_MS(port, termios->c_cflag))
399 old_cr |= CR_MSIE;
400
401 writel((quot>>8) & 0xff, port->membase + UART_BAUDDIV_MSB);
402 writel(quot & 0xff, port->membase + UART_BAUDDIV_LSB);
403 writel(line_cr, port->membase + UART_LINE_CR);
404
405 writel(rts_cr, port->membase + UART_RTS_CR);
406
407 /*
408 * Characters to ignore
409 */
410 port->ignore_status_mask = 0;
411 if (termios->c_iflag & IGNPAR)
412 port->ignore_status_mask |= SR_PE;
413 if (termios->c_iflag & IGNBRK) {
414 port->ignore_status_mask |= SR_BE;
415 /*
416 * If we're ignoring parity and break indicators,
417 * ignore overruns too (for real raw support).
418 */
419 if (termios->c_iflag & IGNPAR)
420 port->ignore_status_mask |= SR_PE;
421 }
422
423 port->read_status_mask = 0;
424 if (termios->c_iflag & (BRKINT | PARMRK))
425 port->read_status_mask |= SR_BE;
426 if (termios->c_iflag & INPCK)
427 port->read_status_mask |= SR_PE | SR_FE;
428
429 writel(old_cr, port->membase + UART_CR);
430
431 spin_unlock_irq(&port->lock);
432 }
433
434 static const char *netx_type(struct uart_port *port)
435 {
436 return port->type == PORT_NETX ? "NETX" : NULL;
437 }
438
439 static void netx_release_port(struct uart_port *port)
440 {
441 release_mem_region(port->mapbase, UART_PORT_SIZE);
442 }
443
444 static int netx_request_port(struct uart_port *port)
445 {
446 return request_mem_region(port->mapbase, UART_PORT_SIZE,
447 DRIVER_NAME) != NULL ? 0 : -EBUSY;
448 }
449
450 static void netx_config_port(struct uart_port *port, int flags)
451 {
452 if (flags & UART_CONFIG_TYPE && netx_request_port(port) == 0)
453 port->type = PORT_NETX;
454 }
455
456 static int
457 netx_verify_port(struct uart_port *port, struct serial_struct *ser)
458 {
459 int ret = 0;
460
461 if (ser->type != PORT_UNKNOWN && ser->type != PORT_NETX)
462 ret = -EINVAL;
463
464 return ret;
465 }
466
467 static struct uart_ops netx_pops = {
468 .tx_empty = netx_tx_empty,
469 .set_mctrl = netx_set_mctrl,
470 .get_mctrl = netx_get_mctrl,
471 .stop_tx = netx_stop_tx,
472 .start_tx = netx_start_tx,
473 .stop_rx = netx_stop_rx,
474 .enable_ms = netx_enable_ms,
475 .break_ctl = netx_break_ctl,
476 .startup = netx_startup,
477 .shutdown = netx_shutdown,
478 .set_termios = netx_set_termios,
479 .type = netx_type,
480 .release_port = netx_release_port,
481 .request_port = netx_request_port,
482 .config_port = netx_config_port,
483 .verify_port = netx_verify_port,
484 };
485
486 static struct netx_port netx_ports[] = {
487 {
488 .port = {
489 .type = PORT_NETX,
490 .iotype = UPIO_MEM,
491 .membase = (char __iomem *)io_p2v(NETX_PA_UART0),
492 .mapbase = NETX_PA_UART0,
493 .irq = NETX_IRQ_UART0,
494 .uartclk = 100000000,
495 .fifosize = 16,
496 .flags = UPF_BOOT_AUTOCONF,
497 .ops = &netx_pops,
498 .line = 0,
499 },
500 }, {
501 .port = {
502 .type = PORT_NETX,
503 .iotype = UPIO_MEM,
504 .membase = (char __iomem *)io_p2v(NETX_PA_UART1),
505 .mapbase = NETX_PA_UART1,
506 .irq = NETX_IRQ_UART1,
507 .uartclk = 100000000,
508 .fifosize = 16,
509 .flags = UPF_BOOT_AUTOCONF,
510 .ops = &netx_pops,
511 .line = 1,
512 },
513 }, {
514 .port = {
515 .type = PORT_NETX,
516 .iotype = UPIO_MEM,
517 .membase = (char __iomem *)io_p2v(NETX_PA_UART2),
518 .mapbase = NETX_PA_UART2,
519 .irq = NETX_IRQ_UART2,
520 .uartclk = 100000000,
521 .fifosize = 16,
522 .flags = UPF_BOOT_AUTOCONF,
523 .ops = &netx_pops,
524 .line = 2,
525 },
526 }
527 };
528
529 #ifdef CONFIG_SERIAL_NETX_CONSOLE
530
531 static void netx_console_putchar(struct uart_port *port, int ch)
532 {
533 while (readl(port->membase + UART_FR) & FR_BUSY);
534 writel(ch, port->membase + UART_DR);
535 }
536
537 static void
538 netx_console_write(struct console *co, const char *s, unsigned int count)
539 {
540 struct uart_port *port = &netx_ports[co->index].port;
541 unsigned char cr_save;
542
543 cr_save = readl(port->membase + UART_CR);
544 writel(cr_save | CR_UART_EN, port->membase + UART_CR);
545
546 uart_console_write(port, s, count, netx_console_putchar);
547
548 while (readl(port->membase + UART_FR) & FR_BUSY);
549 writel(cr_save, port->membase + UART_CR);
550 }
551
552 static void __init
553 netx_console_get_options(struct uart_port *port, int *baud,
554 int *parity, int *bits, int *flow)
555 {
556 unsigned char line_cr;
557
558 *baud = (readl(port->membase + UART_BAUDDIV_MSB) << 8) |
559 readl(port->membase + UART_BAUDDIV_LSB);
560 *baud *= 1000;
561 *baud /= 4096;
562 *baud *= 1000;
563 *baud /= 256;
564 *baud *= 100;
565
566 line_cr = readl(port->membase + UART_LINE_CR);
567 *parity = 'n';
568 if (line_cr & LINE_CR_PEN) {
569 if (line_cr & LINE_CR_EPS)
570 *parity = 'e';
571 else
572 *parity = 'o';
573 }
574
575 switch (line_cr & LINE_CR_BITS_MASK) {
576 case LINE_CR_8BIT:
577 *bits = 8;
578 break;
579 case LINE_CR_7BIT:
580 *bits = 7;
581 break;
582 case LINE_CR_6BIT:
583 *bits = 6;
584 break;
585 case LINE_CR_5BIT:
586 *bits = 5;
587 break;
588 }
589
590 if (readl(port->membase + UART_RTS_CR) & RTS_CR_AUTO)
591 *flow = 'r';
592 }
593
594 static int __init
595 netx_console_setup(struct console *co, char *options)
596 {
597 struct netx_port *sport;
598 int baud = 9600;
599 int bits = 8;
600 int parity = 'n';
601 int flow = 'n';
602
603 /*
604 * Check whether an invalid uart number has been specified, and
605 * if so, search for the first available port that does have
606 * console support.
607 */
608 if (co->index == -1 || co->index >= ARRAY_SIZE(netx_ports))
609 co->index = 0;
610 sport = &netx_ports[co->index];
611
612 if (options) {
613 uart_parse_options(options, &baud, &parity, &bits, &flow);
614 } else {
615 /* if the UART is enabled, assume it has been correctly setup
616 * by the bootloader and get the options
617 */
618 if (readl(sport->port.membase + UART_CR) & CR_UART_EN) {
619 netx_console_get_options(&sport->port, &baud,
620 &parity, &bits, &flow);
621 }
622
623 }
624
625 return uart_set_options(&sport->port, co, baud, parity, bits, flow);
626 }
627
628 static struct uart_driver netx_reg;
629 static struct console netx_console = {
630 .name = "ttyNX",
631 .write = netx_console_write,
632 .device = uart_console_device,
633 .setup = netx_console_setup,
634 .flags = CON_PRINTBUFFER,
635 .index = -1,
636 .data = &netx_reg,
637 };
638
639 static int __init netx_console_init(void)
640 {
641 register_console(&netx_console);
642 return 0;
643 }
644 console_initcall(netx_console_init);
645
646 #define NETX_CONSOLE &netx_console
647 #else
648 #define NETX_CONSOLE NULL
649 #endif
650
651 static struct uart_driver netx_reg = {
652 .owner = THIS_MODULE,
653 .driver_name = DRIVER_NAME,
654 .dev_name = "ttyNX",
655 .major = SERIAL_NX_MAJOR,
656 .minor = MINOR_START,
657 .nr = ARRAY_SIZE(netx_ports),
658 .cons = NETX_CONSOLE,
659 };
660
661 static int serial_netx_suspend(struct platform_device *pdev, pm_message_t state)
662 {
663 struct netx_port *sport = platform_get_drvdata(pdev);
664
665 if (sport)
666 uart_suspend_port(&netx_reg, &sport->port);
667
668 return 0;
669 }
670
671 static int serial_netx_resume(struct platform_device *pdev)
672 {
673 struct netx_port *sport = platform_get_drvdata(pdev);
674
675 if (sport)
676 uart_resume_port(&netx_reg, &sport->port);
677
678 return 0;
679 }
680
681 static int serial_netx_probe(struct platform_device *pdev)
682 {
683 struct uart_port *port = &netx_ports[pdev->id].port;
684
685 dev_info(&pdev->dev, "initialising\n");
686
687 port->dev = &pdev->dev;
688
689 writel(1, port->membase + UART_RXFIFO_IRQLEVEL);
690 uart_add_one_port(&netx_reg, &netx_ports[pdev->id].port);
691 platform_set_drvdata(pdev, &netx_ports[pdev->id]);
692
693 return 0;
694 }
695
696 static int serial_netx_remove(struct platform_device *pdev)
697 {
698 struct netx_port *sport = platform_get_drvdata(pdev);
699
700 platform_set_drvdata(pdev, NULL);
701
702 if (sport)
703 uart_remove_one_port(&netx_reg, &sport->port);
704
705 return 0;
706 }
707
708 static struct platform_driver serial_netx_driver = {
709 .probe = serial_netx_probe,
710 .remove = serial_netx_remove,
711
712 .suspend = serial_netx_suspend,
713 .resume = serial_netx_resume,
714
715 .driver = {
716 .name = DRIVER_NAME,
717 .owner = THIS_MODULE,
718 },
719 };
720
721 static int __init netx_serial_init(void)
722 {
723 int ret;
724
725 printk(KERN_INFO "Serial: NetX driver\n");
726
727 ret = uart_register_driver(&netx_reg);
728 if (ret)
729 return ret;
730
731 ret = platform_driver_register(&serial_netx_driver);
732 if (ret != 0)
733 uart_unregister_driver(&netx_reg);
734
735 return 0;
736 }
737
738 static void __exit netx_serial_exit(void)
739 {
740 platform_driver_unregister(&serial_netx_driver);
741 uart_unregister_driver(&netx_reg);
742 }
743
744 module_init(netx_serial_init);
745 module_exit(netx_serial_exit);
746
747 MODULE_AUTHOR("Sascha Hauer");
748 MODULE_DESCRIPTION("NetX serial port driver");
749 MODULE_LICENSE("GPL");
750 MODULE_ALIAS("platform:" DRIVER_NAME);
751
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