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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Driver for GRLIB serial ports (APBUART)
4 *
5 * Based on linux/drivers/serial/amba.c
6 *
7 * Copyright (C) 2000 Deep Blue Solutions Ltd.
8 * Copyright (C) 2003 Konrad Eisele <eiselekd@web.de>
9 * Copyright (C) 2006 Daniel Hellstrom <daniel@gaisler.com>, Aeroflex Gaisler AB
10 * Copyright (C) 2008 Gilead Kutnick <kutnickg@zin-tech.com>
11 * Copyright (C) 2009 Kristoffer Glembo <kristoffer@gaisler.com>, Aeroflex Gaisler AB
12 */
13
14#include <linux/module.h>
15#include <linux/tty.h>
16#include <linux/tty_flip.h>
17#include <linux/ioport.h>
18#include <linux/init.h>
19#include <linux/serial.h>
20#include <linux/console.h>
21#include <linux/sysrq.h>
22#include <linux/kthread.h>
23#include <linux/device.h>
24#include <linux/of.h>
25#include <linux/of_device.h>
26#include <linux/of_platform.h>
27#include <linux/of_irq.h>
28#include <linux/platform_device.h>
29#include <linux/io.h>
30#include <linux/serial_core.h>
31#include <asm/irq.h>
32
33#include "apbuart.h"
34
35#define SERIAL_APBUART_MAJOR TTY_MAJOR
36#define SERIAL_APBUART_MINOR 64
37#define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
38
39static void apbuart_tx_chars(struct uart_port *port);
40
41static void apbuart_stop_tx(struct uart_port *port)
42{
43 unsigned int cr;
44
45 cr = UART_GET_CTRL(port);
46 cr &= ~UART_CTRL_TI;
47 UART_PUT_CTRL(port, cr);
48}
49
50static void apbuart_start_tx(struct uart_port *port)
51{
52 unsigned int cr;
53
54 cr = UART_GET_CTRL(port);
55 cr |= UART_CTRL_TI;
56 UART_PUT_CTRL(port, cr);
57
58 if (UART_GET_STATUS(port) & UART_STATUS_THE)
59 apbuart_tx_chars(port);
60}
61
62static void apbuart_stop_rx(struct uart_port *port)
63{
64 unsigned int cr;
65
66 cr = UART_GET_CTRL(port);
67 cr &= ~(UART_CTRL_RI);
68 UART_PUT_CTRL(port, cr);
69}
70
71static void apbuart_rx_chars(struct uart_port *port)
72{
73 unsigned int status, ch, rsr, flag;
74 unsigned int max_chars = port->fifosize;
75
76 status = UART_GET_STATUS(port);
77
78 while (UART_RX_DATA(status) && (max_chars--)) {
79
80 ch = UART_GET_CHAR(port);
81 flag = TTY_NORMAL;
82
83 port->icount.rx++;
84
85 rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
86 UART_PUT_STATUS(port, 0);
87 if (rsr & UART_STATUS_ERR) {
88
89 if (rsr & UART_STATUS_BR) {
90 rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
91 port->icount.brk++;
92 if (uart_handle_break(port))
93 goto ignore_char;
94 } else if (rsr & UART_STATUS_PE) {
95 port->icount.parity++;
96 } else if (rsr & UART_STATUS_FE) {
97 port->icount.frame++;
98 }
99 if (rsr & UART_STATUS_OE)
100 port->icount.overrun++;
101
102 rsr &= port->read_status_mask;
103
104 if (rsr & UART_STATUS_PE)
105 flag = TTY_PARITY;
106 else if (rsr & UART_STATUS_FE)
107 flag = TTY_FRAME;
108 }
109
110 if (uart_handle_sysrq_char(port, ch))
111 goto ignore_char;
112
113 uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
114
115
116 ignore_char:
117 status = UART_GET_STATUS(port);
118 }
119
120 tty_flip_buffer_push(&port->state->port);
121}
122
123static void apbuart_tx_chars(struct uart_port *port)
124{
125 struct circ_buf *xmit = &port->state->xmit;
126 int count;
127
128 if (port->x_char) {
129 UART_PUT_CHAR(port, port->x_char);
130 port->icount.tx++;
131 port->x_char = 0;
132 return;
133 }
134
135 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
136 apbuart_stop_tx(port);
137 return;
138 }
139
140 /* amba: fill FIFO */
141 count = port->fifosize >> 1;
142 do {
143 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
144 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
145 port->icount.tx++;
146 if (uart_circ_empty(xmit))
147 break;
148 } while (--count > 0);
149
150 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
151 uart_write_wakeup(port);
152
153 if (uart_circ_empty(xmit))
154 apbuart_stop_tx(port);
155}
156
157static irqreturn_t apbuart_int(int irq, void *dev_id)
158{
159 struct uart_port *port = dev_id;
160 unsigned int status;
161
162 spin_lock(&port->lock);
163
164 status = UART_GET_STATUS(port);
165 if (status & UART_STATUS_DR)
166 apbuart_rx_chars(port);
167 if (status & UART_STATUS_THE)
168 apbuart_tx_chars(port);
169
170 spin_unlock(&port->lock);
171
172 return IRQ_HANDLED;
173}
174
175static unsigned int apbuart_tx_empty(struct uart_port *port)
176{
177 unsigned int status = UART_GET_STATUS(port);
178 return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
179}
180
181static unsigned int apbuart_get_mctrl(struct uart_port *port)
182{
183 /* The GRLIB APBUART handles flow control in hardware */
184 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
185}
186
187static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
188{
189 /* The GRLIB APBUART handles flow control in hardware */
190}
191
192static void apbuart_break_ctl(struct uart_port *port, int break_state)
193{
194 /* We don't support sending break */
195}
196
197static int apbuart_startup(struct uart_port *port)
198{
199 int retval;
200 unsigned int cr;
201
202 /* Allocate the IRQ */
203 retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
204 if (retval)
205 return retval;
206
207 /* Finally, enable interrupts */
208 cr = UART_GET_CTRL(port);
209 UART_PUT_CTRL(port,
210 cr | UART_CTRL_RE | UART_CTRL_TE |
211 UART_CTRL_RI | UART_CTRL_TI);
212
213 return 0;
214}
215
216static void apbuart_shutdown(struct uart_port *port)
217{
218 unsigned int cr;
219
220 /* disable all interrupts, disable the port */
221 cr = UART_GET_CTRL(port);
222 UART_PUT_CTRL(port,
223 cr & ~(UART_CTRL_RE | UART_CTRL_TE |
224 UART_CTRL_RI | UART_CTRL_TI));
225
226 /* Free the interrupt */
227 free_irq(port->irq, port);
228}
229
230static void apbuart_set_termios(struct uart_port *port,
231 struct ktermios *termios, struct ktermios *old)
232{
233 unsigned int cr;
234 unsigned long flags;
235 unsigned int baud, quot;
236
237 /* Ask the core to calculate the divisor for us. */
238 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
239 if (baud == 0)
240 panic("invalid baudrate %i\n", port->uartclk / 16);
241
242 /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
243 quot = (uart_get_divisor(port, baud)) * 2;
244 cr = UART_GET_CTRL(port);
245 cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
246
247 if (termios->c_cflag & PARENB) {
248 cr |= UART_CTRL_PE;
249 if ((termios->c_cflag & PARODD))
250 cr |= UART_CTRL_PS;
251 }
252
253 /* Enable flow control. */
254 if (termios->c_cflag & CRTSCTS)
255 cr |= UART_CTRL_FL;
256
257 spin_lock_irqsave(&port->lock, flags);
258
259 /* Update the per-port timeout. */
260 uart_update_timeout(port, termios->c_cflag, baud);
261
262 port->read_status_mask = UART_STATUS_OE;
263 if (termios->c_iflag & INPCK)
264 port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
265
266 /* Characters to ignore */
267 port->ignore_status_mask = 0;
268 if (termios->c_iflag & IGNPAR)
269 port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
270
271 /* Ignore all characters if CREAD is not set. */
272 if ((termios->c_cflag & CREAD) == 0)
273 port->ignore_status_mask |= UART_DUMMY_RSR_RX;
274
275 /* Set baud rate */
276 quot -= 1;
277 UART_PUT_SCAL(port, quot);
278 UART_PUT_CTRL(port, cr);
279
280 spin_unlock_irqrestore(&port->lock, flags);
281}
282
283static const char *apbuart_type(struct uart_port *port)
284{
285 return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
286}
287
288static void apbuart_release_port(struct uart_port *port)
289{
290 release_mem_region(port->mapbase, 0x100);
291}
292
293static int apbuart_request_port(struct uart_port *port)
294{
295 return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
296 != NULL ? 0 : -EBUSY;
297 return 0;
298}
299
300/* Configure/autoconfigure the port */
301static void apbuart_config_port(struct uart_port *port, int flags)
302{
303 if (flags & UART_CONFIG_TYPE) {
304 port->type = PORT_APBUART;
305 apbuart_request_port(port);
306 }
307}
308
309/* Verify the new serial_struct (for TIOCSSERIAL) */
310static int apbuart_verify_port(struct uart_port *port,
311 struct serial_struct *ser)
312{
313 int ret = 0;
314 if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
315 ret = -EINVAL;
316 if (ser->irq < 0 || ser->irq >= NR_IRQS)
317 ret = -EINVAL;
318 if (ser->baud_base < 9600)
319 ret = -EINVAL;
320 return ret;
321}
322
323static const struct uart_ops grlib_apbuart_ops = {
324 .tx_empty = apbuart_tx_empty,
325 .set_mctrl = apbuart_set_mctrl,
326 .get_mctrl = apbuart_get_mctrl,
327 .stop_tx = apbuart_stop_tx,
328 .start_tx = apbuart_start_tx,
329 .stop_rx = apbuart_stop_rx,
330 .break_ctl = apbuart_break_ctl,
331 .startup = apbuart_startup,
332 .shutdown = apbuart_shutdown,
333 .set_termios = apbuart_set_termios,
334 .type = apbuart_type,
335 .release_port = apbuart_release_port,
336 .request_port = apbuart_request_port,
337 .config_port = apbuart_config_port,
338 .verify_port = apbuart_verify_port,
339};
340
341static struct uart_port grlib_apbuart_ports[UART_NR];
342static struct device_node *grlib_apbuart_nodes[UART_NR];
343
344static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
345{
346 int ctrl, loop = 0;
347 int status;
348 int fifosize;
349 unsigned long flags;
350
351 ctrl = UART_GET_CTRL(port);
352
353 /*
354 * Enable the transceiver and wait for it to be ready to send data.
355 * Clear interrupts so that this process will not be externally
356 * interrupted in the middle (which can cause the transceiver to
357 * drain prematurely).
358 */
359
360 local_irq_save(flags);
361
362 UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
363
364 while (!UART_TX_READY(UART_GET_STATUS(port)))
365 loop++;
366
367 /*
368 * Disable the transceiver so data isn't actually sent during the
369 * actual test.
370 */
371
372 UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
373
374 fifosize = 1;
375 UART_PUT_CHAR(port, 0);
376
377 /*
378 * So long as transmitting a character increments the tranceivier FIFO
379 * length the FIFO must be at least that big. These bytes will
380 * automatically drain off of the FIFO.
381 */
382
383 status = UART_GET_STATUS(port);
384 while (((status >> 20) & 0x3F) == fifosize) {
385 fifosize++;
386 UART_PUT_CHAR(port, 0);
387 status = UART_GET_STATUS(port);
388 }
389
390 fifosize--;
391
392 UART_PUT_CTRL(port, ctrl);
393 local_irq_restore(flags);
394
395 if (fifosize == 0)
396 fifosize = 1;
397
398 return fifosize;
399}
400
401static void apbuart_flush_fifo(struct uart_port *port)
402{
403 int i;
404
405 for (i = 0; i < port->fifosize; i++)
406 UART_GET_CHAR(port);
407}
408
409
410/* ======================================================================== */
411/* Console driver, if enabled */
412/* ======================================================================== */
413
414#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
415
416static void apbuart_console_putchar(struct uart_port *port, int ch)
417{
418 unsigned int status;
419 do {
420 status = UART_GET_STATUS(port);
421 } while (!UART_TX_READY(status));
422 UART_PUT_CHAR(port, ch);
423}
424
425static void
426apbuart_console_write(struct console *co, const char *s, unsigned int count)
427{
428 struct uart_port *port = &grlib_apbuart_ports[co->index];
429 unsigned int status, old_cr, new_cr;
430
431 /* First save the CR then disable the interrupts */
432 old_cr = UART_GET_CTRL(port);
433 new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
434 UART_PUT_CTRL(port, new_cr);
435
436 uart_console_write(port, s, count, apbuart_console_putchar);
437
438 /*
439 * Finally, wait for transmitter to become empty
440 * and restore the TCR
441 */
442 do {
443 status = UART_GET_STATUS(port);
444 } while (!UART_TX_READY(status));
445 UART_PUT_CTRL(port, old_cr);
446}
447
448static void __init
449apbuart_console_get_options(struct uart_port *port, int *baud,
450 int *parity, int *bits)
451{
452 if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
453
454 unsigned int quot, status;
455 status = UART_GET_STATUS(port);
456
457 *parity = 'n';
458 if (status & UART_CTRL_PE) {
459 if ((status & UART_CTRL_PS) == 0)
460 *parity = 'e';
461 else
462 *parity = 'o';
463 }
464
465 *bits = 8;
466 quot = UART_GET_SCAL(port) / 8;
467 *baud = port->uartclk / (16 * (quot + 1));
468 }
469}
470
471static int __init apbuart_console_setup(struct console *co, char *options)
472{
473 struct uart_port *port;
474 int baud = 38400;
475 int bits = 8;
476 int parity = 'n';
477 int flow = 'n';
478
479 pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
480 co, co->index, options);
481
482 /*
483 * Check whether an invalid uart number has been specified, and
484 * if so, search for the first available port that does have
485 * console support.
486 */
487 if (co->index >= grlib_apbuart_port_nr)
488 co->index = 0;
489
490 port = &grlib_apbuart_ports[co->index];
491
492 spin_lock_init(&port->lock);
493
494 if (options)
495 uart_parse_options(options, &baud, &parity, &bits, &flow);
496 else
497 apbuart_console_get_options(port, &baud, &parity, &bits);
498
499 return uart_set_options(port, co, baud, parity, bits, flow);
500}
501
502static struct uart_driver grlib_apbuart_driver;
503
504static struct console grlib_apbuart_console = {
505 .name = "ttyS",
506 .write = apbuart_console_write,
507 .device = uart_console_device,
508 .setup = apbuart_console_setup,
509 .flags = CON_PRINTBUFFER,
510 .index = -1,
511 .data = &grlib_apbuart_driver,
512};
513
514
515static int grlib_apbuart_configure(void);
516
517static int __init apbuart_console_init(void)
518{
519 if (grlib_apbuart_configure())
520 return -ENODEV;
521 register_console(&grlib_apbuart_console);
522 return 0;
523}
524
525console_initcall(apbuart_console_init);
526
527#define APBUART_CONSOLE (&grlib_apbuart_console)
528#else
529#define APBUART_CONSOLE NULL
530#endif
531
532static struct uart_driver grlib_apbuart_driver = {
533 .owner = THIS_MODULE,
534 .driver_name = "serial",
535 .dev_name = "ttyS",
536 .major = SERIAL_APBUART_MAJOR,
537 .minor = SERIAL_APBUART_MINOR,
538 .nr = UART_NR,
539 .cons = APBUART_CONSOLE,
540};
541
542
543/* ======================================================================== */
544/* OF Platform Driver */
545/* ======================================================================== */
546
547static int apbuart_probe(struct platform_device *op)
548{
549 int i;
550 struct uart_port *port = NULL;
551
552 for (i = 0; i < grlib_apbuart_port_nr; i++) {
553 if (op->dev.of_node == grlib_apbuart_nodes[i])
554 break;
555 }
556
557 port = &grlib_apbuart_ports[i];
558 port->dev = &op->dev;
559 port->irq = op->archdata.irqs[0];
560
561 uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
562
563 apbuart_flush_fifo((struct uart_port *) port);
564
565 printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
566 (unsigned long long) port->mapbase, port->irq);
567 return 0;
568}
569
570static const struct of_device_id apbuart_match[] = {
571 {
572 .name = "GAISLER_APBUART",
573 },
574 {
575 .name = "01_00c",
576 },
577 {},
578};
579MODULE_DEVICE_TABLE(of, apbuart_match);
580
581static struct platform_driver grlib_apbuart_of_driver = {
582 .probe = apbuart_probe,
583 .driver = {
584 .name = "grlib-apbuart",
585 .of_match_table = apbuart_match,
586 },
587};
588
589
590static int __init grlib_apbuart_configure(void)
591{
592 struct device_node *np;
593 int line = 0;
594
595 for_each_matching_node(np, apbuart_match) {
596 const int *ampopts;
597 const u32 *freq_hz;
598 const struct amba_prom_registers *regs;
599 struct uart_port *port;
600 unsigned long addr;
601
602 ampopts = of_get_property(np, "ampopts", NULL);
603 if (ampopts && (*ampopts == 0))
604 continue; /* Ignore if used by another OS instance */
605 regs = of_get_property(np, "reg", NULL);
606 /* Frequency of APB Bus is frequency of UART */
607 freq_hz = of_get_property(np, "freq", NULL);
608
609 if (!regs || !freq_hz || (*freq_hz == 0))
610 continue;
611
612 grlib_apbuart_nodes[line] = np;
613
614 addr = regs->phys_addr;
615
616 port = &grlib_apbuart_ports[line];
617
618 port->mapbase = addr;
619 port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
620 port->irq = 0;
621 port->iotype = UPIO_MEM;
622 port->ops = &grlib_apbuart_ops;
623 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE);
624 port->flags = UPF_BOOT_AUTOCONF;
625 port->line = line;
626 port->uartclk = *freq_hz;
627 port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
628 line++;
629
630 /* We support maximum UART_NR uarts ... */
631 if (line == UART_NR)
632 break;
633 }
634
635 grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
636 return line ? 0 : -ENODEV;
637}
638
639static int __init grlib_apbuart_init(void)
640{
641 int ret;
642
643 /* Find all APBUARTS in device the tree and initialize their ports */
644 ret = grlib_apbuart_configure();
645 if (ret)
646 return ret;
647
648 printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
649
650 ret = uart_register_driver(&grlib_apbuart_driver);
651
652 if (ret) {
653 printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
654 __FILE__, ret);
655 return ret;
656 }
657
658 ret = platform_driver_register(&grlib_apbuart_of_driver);
659 if (ret) {
660 printk(KERN_ERR
661 "%s: platform_driver_register failed (%i)\n",
662 __FILE__, ret);
663 uart_unregister_driver(&grlib_apbuart_driver);
664 return ret;
665 }
666
667 return ret;
668}
669
670static void __exit grlib_apbuart_exit(void)
671{
672 int i;
673
674 for (i = 0; i < grlib_apbuart_port_nr; i++)
675 uart_remove_one_port(&grlib_apbuart_driver,
676 &grlib_apbuart_ports[i]);
677
678 uart_unregister_driver(&grlib_apbuart_driver);
679 platform_driver_unregister(&grlib_apbuart_of_driver);
680}
681
682module_init(grlib_apbuart_init);
683module_exit(grlib_apbuart_exit);
684
685MODULE_AUTHOR("Aeroflex Gaisler AB");
686MODULE_DESCRIPTION("GRLIB APBUART serial driver");
687MODULE_VERSION("2.1");
688MODULE_LICENSE("GPL");
1/*
2 * Driver for GRLIB serial ports (APBUART)
3 *
4 * Based on linux/drivers/serial/amba.c
5 *
6 * Copyright (C) 2000 Deep Blue Solutions Ltd.
7 * Copyright (C) 2003 Konrad Eisele <eiselekd@web.de>
8 * Copyright (C) 2006 Daniel Hellstrom <daniel@gaisler.com>, Aeroflex Gaisler AB
9 * Copyright (C) 2008 Gilead Kutnick <kutnickg@zin-tech.com>
10 * Copyright (C) 2009 Kristoffer Glembo <kristoffer@gaisler.com>, Aeroflex Gaisler AB
11 */
12
13#if defined(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
14#define SUPPORT_SYSRQ
15#endif
16
17#include <linux/module.h>
18#include <linux/tty.h>
19#include <linux/tty_flip.h>
20#include <linux/ioport.h>
21#include <linux/init.h>
22#include <linux/serial.h>
23#include <linux/console.h>
24#include <linux/sysrq.h>
25#include <linux/kthread.h>
26#include <linux/device.h>
27#include <linux/of.h>
28#include <linux/of_device.h>
29#include <linux/of_platform.h>
30#include <linux/of_irq.h>
31#include <linux/platform_device.h>
32#include <linux/io.h>
33#include <linux/serial_core.h>
34#include <asm/irq.h>
35
36#include "apbuart.h"
37
38#define SERIAL_APBUART_MAJOR TTY_MAJOR
39#define SERIAL_APBUART_MINOR 64
40#define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
41
42static void apbuart_tx_chars(struct uart_port *port);
43
44static void apbuart_stop_tx(struct uart_port *port)
45{
46 unsigned int cr;
47
48 cr = UART_GET_CTRL(port);
49 cr &= ~UART_CTRL_TI;
50 UART_PUT_CTRL(port, cr);
51}
52
53static void apbuart_start_tx(struct uart_port *port)
54{
55 unsigned int cr;
56
57 cr = UART_GET_CTRL(port);
58 cr |= UART_CTRL_TI;
59 UART_PUT_CTRL(port, cr);
60
61 if (UART_GET_STATUS(port) & UART_STATUS_THE)
62 apbuart_tx_chars(port);
63}
64
65static void apbuart_stop_rx(struct uart_port *port)
66{
67 unsigned int cr;
68
69 cr = UART_GET_CTRL(port);
70 cr &= ~(UART_CTRL_RI);
71 UART_PUT_CTRL(port, cr);
72}
73
74static void apbuart_rx_chars(struct uart_port *port)
75{
76 unsigned int status, ch, rsr, flag;
77 unsigned int max_chars = port->fifosize;
78
79 status = UART_GET_STATUS(port);
80
81 while (UART_RX_DATA(status) && (max_chars--)) {
82
83 ch = UART_GET_CHAR(port);
84 flag = TTY_NORMAL;
85
86 port->icount.rx++;
87
88 rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
89 UART_PUT_STATUS(port, 0);
90 if (rsr & UART_STATUS_ERR) {
91
92 if (rsr & UART_STATUS_BR) {
93 rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
94 port->icount.brk++;
95 if (uart_handle_break(port))
96 goto ignore_char;
97 } else if (rsr & UART_STATUS_PE) {
98 port->icount.parity++;
99 } else if (rsr & UART_STATUS_FE) {
100 port->icount.frame++;
101 }
102 if (rsr & UART_STATUS_OE)
103 port->icount.overrun++;
104
105 rsr &= port->read_status_mask;
106
107 if (rsr & UART_STATUS_PE)
108 flag = TTY_PARITY;
109 else if (rsr & UART_STATUS_FE)
110 flag = TTY_FRAME;
111 }
112
113 if (uart_handle_sysrq_char(port, ch))
114 goto ignore_char;
115
116 uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
117
118
119 ignore_char:
120 status = UART_GET_STATUS(port);
121 }
122
123 spin_unlock(&port->lock);
124 tty_flip_buffer_push(&port->state->port);
125 spin_lock(&port->lock);
126}
127
128static void apbuart_tx_chars(struct uart_port *port)
129{
130 struct circ_buf *xmit = &port->state->xmit;
131 int count;
132
133 if (port->x_char) {
134 UART_PUT_CHAR(port, port->x_char);
135 port->icount.tx++;
136 port->x_char = 0;
137 return;
138 }
139
140 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
141 apbuart_stop_tx(port);
142 return;
143 }
144
145 /* amba: fill FIFO */
146 count = port->fifosize >> 1;
147 do {
148 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
149 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
150 port->icount.tx++;
151 if (uart_circ_empty(xmit))
152 break;
153 } while (--count > 0);
154
155 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
156 uart_write_wakeup(port);
157
158 if (uart_circ_empty(xmit))
159 apbuart_stop_tx(port);
160}
161
162static irqreturn_t apbuart_int(int irq, void *dev_id)
163{
164 struct uart_port *port = dev_id;
165 unsigned int status;
166
167 spin_lock(&port->lock);
168
169 status = UART_GET_STATUS(port);
170 if (status & UART_STATUS_DR)
171 apbuart_rx_chars(port);
172 if (status & UART_STATUS_THE)
173 apbuart_tx_chars(port);
174
175 spin_unlock(&port->lock);
176
177 return IRQ_HANDLED;
178}
179
180static unsigned int apbuart_tx_empty(struct uart_port *port)
181{
182 unsigned int status = UART_GET_STATUS(port);
183 return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
184}
185
186static unsigned int apbuart_get_mctrl(struct uart_port *port)
187{
188 /* The GRLIB APBUART handles flow control in hardware */
189 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
190}
191
192static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
193{
194 /* The GRLIB APBUART handles flow control in hardware */
195}
196
197static void apbuart_break_ctl(struct uart_port *port, int break_state)
198{
199 /* We don't support sending break */
200}
201
202static int apbuart_startup(struct uart_port *port)
203{
204 int retval;
205 unsigned int cr;
206
207 /* Allocate the IRQ */
208 retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
209 if (retval)
210 return retval;
211
212 /* Finally, enable interrupts */
213 cr = UART_GET_CTRL(port);
214 UART_PUT_CTRL(port,
215 cr | UART_CTRL_RE | UART_CTRL_TE |
216 UART_CTRL_RI | UART_CTRL_TI);
217
218 return 0;
219}
220
221static void apbuart_shutdown(struct uart_port *port)
222{
223 unsigned int cr;
224
225 /* disable all interrupts, disable the port */
226 cr = UART_GET_CTRL(port);
227 UART_PUT_CTRL(port,
228 cr & ~(UART_CTRL_RE | UART_CTRL_TE |
229 UART_CTRL_RI | UART_CTRL_TI));
230
231 /* Free the interrupt */
232 free_irq(port->irq, port);
233}
234
235static void apbuart_set_termios(struct uart_port *port,
236 struct ktermios *termios, struct ktermios *old)
237{
238 unsigned int cr;
239 unsigned long flags;
240 unsigned int baud, quot;
241
242 /* Ask the core to calculate the divisor for us. */
243 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
244 if (baud == 0)
245 panic("invalid baudrate %i\n", port->uartclk / 16);
246
247 /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
248 quot = (uart_get_divisor(port, baud)) * 2;
249 cr = UART_GET_CTRL(port);
250 cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
251
252 if (termios->c_cflag & PARENB) {
253 cr |= UART_CTRL_PE;
254 if ((termios->c_cflag & PARODD))
255 cr |= UART_CTRL_PS;
256 }
257
258 /* Enable flow control. */
259 if (termios->c_cflag & CRTSCTS)
260 cr |= UART_CTRL_FL;
261
262 spin_lock_irqsave(&port->lock, flags);
263
264 /* Update the per-port timeout. */
265 uart_update_timeout(port, termios->c_cflag, baud);
266
267 port->read_status_mask = UART_STATUS_OE;
268 if (termios->c_iflag & INPCK)
269 port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
270
271 /* Characters to ignore */
272 port->ignore_status_mask = 0;
273 if (termios->c_iflag & IGNPAR)
274 port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
275
276 /* Ignore all characters if CREAD is not set. */
277 if ((termios->c_cflag & CREAD) == 0)
278 port->ignore_status_mask |= UART_DUMMY_RSR_RX;
279
280 /* Set baud rate */
281 quot -= 1;
282 UART_PUT_SCAL(port, quot);
283 UART_PUT_CTRL(port, cr);
284
285 spin_unlock_irqrestore(&port->lock, flags);
286}
287
288static const char *apbuart_type(struct uart_port *port)
289{
290 return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
291}
292
293static void apbuart_release_port(struct uart_port *port)
294{
295 release_mem_region(port->mapbase, 0x100);
296}
297
298static int apbuart_request_port(struct uart_port *port)
299{
300 return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
301 != NULL ? 0 : -EBUSY;
302 return 0;
303}
304
305/* Configure/autoconfigure the port */
306static void apbuart_config_port(struct uart_port *port, int flags)
307{
308 if (flags & UART_CONFIG_TYPE) {
309 port->type = PORT_APBUART;
310 apbuart_request_port(port);
311 }
312}
313
314/* Verify the new serial_struct (for TIOCSSERIAL) */
315static int apbuart_verify_port(struct uart_port *port,
316 struct serial_struct *ser)
317{
318 int ret = 0;
319 if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
320 ret = -EINVAL;
321 if (ser->irq < 0 || ser->irq >= NR_IRQS)
322 ret = -EINVAL;
323 if (ser->baud_base < 9600)
324 ret = -EINVAL;
325 return ret;
326}
327
328static struct uart_ops grlib_apbuart_ops = {
329 .tx_empty = apbuart_tx_empty,
330 .set_mctrl = apbuart_set_mctrl,
331 .get_mctrl = apbuart_get_mctrl,
332 .stop_tx = apbuart_stop_tx,
333 .start_tx = apbuart_start_tx,
334 .stop_rx = apbuart_stop_rx,
335 .break_ctl = apbuart_break_ctl,
336 .startup = apbuart_startup,
337 .shutdown = apbuart_shutdown,
338 .set_termios = apbuart_set_termios,
339 .type = apbuart_type,
340 .release_port = apbuart_release_port,
341 .request_port = apbuart_request_port,
342 .config_port = apbuart_config_port,
343 .verify_port = apbuart_verify_port,
344};
345
346static struct uart_port grlib_apbuart_ports[UART_NR];
347static struct device_node *grlib_apbuart_nodes[UART_NR];
348
349static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
350{
351 int ctrl, loop = 0;
352 int status;
353 int fifosize;
354 unsigned long flags;
355
356 ctrl = UART_GET_CTRL(port);
357
358 /*
359 * Enable the transceiver and wait for it to be ready to send data.
360 * Clear interrupts so that this process will not be externally
361 * interrupted in the middle (which can cause the transceiver to
362 * drain prematurely).
363 */
364
365 local_irq_save(flags);
366
367 UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
368
369 while (!UART_TX_READY(UART_GET_STATUS(port)))
370 loop++;
371
372 /*
373 * Disable the transceiver so data isn't actually sent during the
374 * actual test.
375 */
376
377 UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
378
379 fifosize = 1;
380 UART_PUT_CHAR(port, 0);
381
382 /*
383 * So long as transmitting a character increments the tranceivier FIFO
384 * length the FIFO must be at least that big. These bytes will
385 * automatically drain off of the FIFO.
386 */
387
388 status = UART_GET_STATUS(port);
389 while (((status >> 20) & 0x3F) == fifosize) {
390 fifosize++;
391 UART_PUT_CHAR(port, 0);
392 status = UART_GET_STATUS(port);
393 }
394
395 fifosize--;
396
397 UART_PUT_CTRL(port, ctrl);
398 local_irq_restore(flags);
399
400 if (fifosize == 0)
401 fifosize = 1;
402
403 return fifosize;
404}
405
406static void apbuart_flush_fifo(struct uart_port *port)
407{
408 int i;
409
410 for (i = 0; i < port->fifosize; i++)
411 UART_GET_CHAR(port);
412}
413
414
415/* ======================================================================== */
416/* Console driver, if enabled */
417/* ======================================================================== */
418
419#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
420
421static void apbuart_console_putchar(struct uart_port *port, int ch)
422{
423 unsigned int status;
424 do {
425 status = UART_GET_STATUS(port);
426 } while (!UART_TX_READY(status));
427 UART_PUT_CHAR(port, ch);
428}
429
430static void
431apbuart_console_write(struct console *co, const char *s, unsigned int count)
432{
433 struct uart_port *port = &grlib_apbuart_ports[co->index];
434 unsigned int status, old_cr, new_cr;
435
436 /* First save the CR then disable the interrupts */
437 old_cr = UART_GET_CTRL(port);
438 new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
439 UART_PUT_CTRL(port, new_cr);
440
441 uart_console_write(port, s, count, apbuart_console_putchar);
442
443 /*
444 * Finally, wait for transmitter to become empty
445 * and restore the TCR
446 */
447 do {
448 status = UART_GET_STATUS(port);
449 } while (!UART_TX_READY(status));
450 UART_PUT_CTRL(port, old_cr);
451}
452
453static void __init
454apbuart_console_get_options(struct uart_port *port, int *baud,
455 int *parity, int *bits)
456{
457 if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
458
459 unsigned int quot, status;
460 status = UART_GET_STATUS(port);
461
462 *parity = 'n';
463 if (status & UART_CTRL_PE) {
464 if ((status & UART_CTRL_PS) == 0)
465 *parity = 'e';
466 else
467 *parity = 'o';
468 }
469
470 *bits = 8;
471 quot = UART_GET_SCAL(port) / 8;
472 *baud = port->uartclk / (16 * (quot + 1));
473 }
474}
475
476static int __init apbuart_console_setup(struct console *co, char *options)
477{
478 struct uart_port *port;
479 int baud = 38400;
480 int bits = 8;
481 int parity = 'n';
482 int flow = 'n';
483
484 pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
485 co, co->index, options);
486
487 /*
488 * Check whether an invalid uart number has been specified, and
489 * if so, search for the first available port that does have
490 * console support.
491 */
492 if (co->index >= grlib_apbuart_port_nr)
493 co->index = 0;
494
495 port = &grlib_apbuart_ports[co->index];
496
497 spin_lock_init(&port->lock);
498
499 if (options)
500 uart_parse_options(options, &baud, &parity, &bits, &flow);
501 else
502 apbuart_console_get_options(port, &baud, &parity, &bits);
503
504 return uart_set_options(port, co, baud, parity, bits, flow);
505}
506
507static struct uart_driver grlib_apbuart_driver;
508
509static struct console grlib_apbuart_console = {
510 .name = "ttyS",
511 .write = apbuart_console_write,
512 .device = uart_console_device,
513 .setup = apbuart_console_setup,
514 .flags = CON_PRINTBUFFER,
515 .index = -1,
516 .data = &grlib_apbuart_driver,
517};
518
519
520static int grlib_apbuart_configure(void);
521
522static int __init apbuart_console_init(void)
523{
524 if (grlib_apbuart_configure())
525 return -ENODEV;
526 register_console(&grlib_apbuart_console);
527 return 0;
528}
529
530console_initcall(apbuart_console_init);
531
532#define APBUART_CONSOLE (&grlib_apbuart_console)
533#else
534#define APBUART_CONSOLE NULL
535#endif
536
537static struct uart_driver grlib_apbuart_driver = {
538 .owner = THIS_MODULE,
539 .driver_name = "serial",
540 .dev_name = "ttyS",
541 .major = SERIAL_APBUART_MAJOR,
542 .minor = SERIAL_APBUART_MINOR,
543 .nr = UART_NR,
544 .cons = APBUART_CONSOLE,
545};
546
547
548/* ======================================================================== */
549/* OF Platform Driver */
550/* ======================================================================== */
551
552static int apbuart_probe(struct platform_device *op)
553{
554 int i;
555 struct uart_port *port = NULL;
556
557 for (i = 0; i < grlib_apbuart_port_nr; i++) {
558 if (op->dev.of_node == grlib_apbuart_nodes[i])
559 break;
560 }
561
562 port = &grlib_apbuart_ports[i];
563 port->dev = &op->dev;
564 port->irq = op->archdata.irqs[0];
565
566 uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
567
568 apbuart_flush_fifo((struct uart_port *) port);
569
570 printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
571 (unsigned long long) port->mapbase, port->irq);
572 return 0;
573}
574
575static const struct of_device_id apbuart_match[] = {
576 {
577 .name = "GAISLER_APBUART",
578 },
579 {
580 .name = "01_00c",
581 },
582 {},
583};
584MODULE_DEVICE_TABLE(of, apbuart_match);
585
586static struct platform_driver grlib_apbuart_of_driver = {
587 .probe = apbuart_probe,
588 .driver = {
589 .name = "grlib-apbuart",
590 .of_match_table = apbuart_match,
591 },
592};
593
594
595static int __init grlib_apbuart_configure(void)
596{
597 struct device_node *np;
598 int line = 0;
599
600 for_each_matching_node(np, apbuart_match) {
601 const int *ampopts;
602 const u32 *freq_hz;
603 const struct amba_prom_registers *regs;
604 struct uart_port *port;
605 unsigned long addr;
606
607 ampopts = of_get_property(np, "ampopts", NULL);
608 if (ampopts && (*ampopts == 0))
609 continue; /* Ignore if used by another OS instance */
610 regs = of_get_property(np, "reg", NULL);
611 /* Frequency of APB Bus is frequency of UART */
612 freq_hz = of_get_property(np, "freq", NULL);
613
614 if (!regs || !freq_hz || (*freq_hz == 0))
615 continue;
616
617 grlib_apbuart_nodes[line] = np;
618
619 addr = regs->phys_addr;
620
621 port = &grlib_apbuart_ports[line];
622
623 port->mapbase = addr;
624 port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
625 port->irq = 0;
626 port->iotype = UPIO_MEM;
627 port->ops = &grlib_apbuart_ops;
628 port->flags = UPF_BOOT_AUTOCONF;
629 port->line = line;
630 port->uartclk = *freq_hz;
631 port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
632 line++;
633
634 /* We support maximum UART_NR uarts ... */
635 if (line == UART_NR)
636 break;
637 }
638
639 grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
640 return line ? 0 : -ENODEV;
641}
642
643static int __init grlib_apbuart_init(void)
644{
645 int ret;
646
647 /* Find all APBUARTS in device the tree and initialize their ports */
648 ret = grlib_apbuart_configure();
649 if (ret)
650 return ret;
651
652 printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
653
654 ret = uart_register_driver(&grlib_apbuart_driver);
655
656 if (ret) {
657 printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
658 __FILE__, ret);
659 return ret;
660 }
661
662 ret = platform_driver_register(&grlib_apbuart_of_driver);
663 if (ret) {
664 printk(KERN_ERR
665 "%s: platform_driver_register failed (%i)\n",
666 __FILE__, ret);
667 uart_unregister_driver(&grlib_apbuart_driver);
668 return ret;
669 }
670
671 return ret;
672}
673
674static void __exit grlib_apbuart_exit(void)
675{
676 int i;
677
678 for (i = 0; i < grlib_apbuart_port_nr; i++)
679 uart_remove_one_port(&grlib_apbuart_driver,
680 &grlib_apbuart_ports[i]);
681
682 uart_unregister_driver(&grlib_apbuart_driver);
683 platform_driver_unregister(&grlib_apbuart_of_driver);
684}
685
686module_init(grlib_apbuart_init);
687module_exit(grlib_apbuart_exit);
688
689MODULE_AUTHOR("Aeroflex Gaisler AB");
690MODULE_DESCRIPTION("GRLIB APBUART serial driver");
691MODULE_VERSION("2.1");
692MODULE_LICENSE("GPL");