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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/ioport.h>
20#include <linux/init.h>
21#include <linux/serial.h>
22#include <linux/console.h>
23#include <linux/sysrq.h>
24#include <linux/kthread.h>
25#include <linux/device.h>
26#include <linux/of.h>
27#include <linux/of_device.h>
28#include <linux/of_platform.h>
29#include <linux/of_irq.h>
30#include <linux/platform_device.h>
31#include <linux/io.h>
32#include <linux/serial_core.h>
33#include <asm/irq.h>
34
35#include "apbuart.h"
36
37#define SERIAL_APBUART_MAJOR TTY_MAJOR
38#define SERIAL_APBUART_MINOR 64
39#define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
40
41static void apbuart_tx_chars(struct uart_port *port);
42
43static void apbuart_stop_tx(struct uart_port *port)
44{
45 unsigned int cr;
46
47 cr = UART_GET_CTRL(port);
48 cr &= ~UART_CTRL_TI;
49 UART_PUT_CTRL(port, cr);
50}
51
52static void apbuart_start_tx(struct uart_port *port)
53{
54 unsigned int cr;
55
56 cr = UART_GET_CTRL(port);
57 cr |= UART_CTRL_TI;
58 UART_PUT_CTRL(port, cr);
59
60 if (UART_GET_STATUS(port) & UART_STATUS_THE)
61 apbuart_tx_chars(port);
62}
63
64static void apbuart_stop_rx(struct uart_port *port)
65{
66 unsigned int cr;
67
68 cr = UART_GET_CTRL(port);
69 cr &= ~(UART_CTRL_RI);
70 UART_PUT_CTRL(port, cr);
71}
72
73static void apbuart_enable_ms(struct uart_port *port)
74{
75 /* No modem status change interrupts for APBUART */
76}
77
78static void apbuart_rx_chars(struct uart_port *port)
79{
80 struct tty_struct *tty = port->state->port.tty;
81 unsigned int status, ch, rsr, flag;
82 unsigned int max_chars = port->fifosize;
83
84 status = UART_GET_STATUS(port);
85
86 while (UART_RX_DATA(status) && (max_chars--)) {
87
88 ch = UART_GET_CHAR(port);
89 flag = TTY_NORMAL;
90
91 port->icount.rx++;
92
93 rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
94 UART_PUT_STATUS(port, 0);
95 if (rsr & UART_STATUS_ERR) {
96
97 if (rsr & UART_STATUS_BR) {
98 rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
99 port->icount.brk++;
100 if (uart_handle_break(port))
101 goto ignore_char;
102 } else if (rsr & UART_STATUS_PE) {
103 port->icount.parity++;
104 } else if (rsr & UART_STATUS_FE) {
105 port->icount.frame++;
106 }
107 if (rsr & UART_STATUS_OE)
108 port->icount.overrun++;
109
110 rsr &= port->read_status_mask;
111
112 if (rsr & UART_STATUS_PE)
113 flag = TTY_PARITY;
114 else if (rsr & UART_STATUS_FE)
115 flag = TTY_FRAME;
116 }
117
118 if (uart_handle_sysrq_char(port, ch))
119 goto ignore_char;
120
121 uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
122
123
124 ignore_char:
125 status = UART_GET_STATUS(port);
126 }
127
128 tty_flip_buffer_push(tty);
129}
130
131static void apbuart_tx_chars(struct uart_port *port)
132{
133 struct circ_buf *xmit = &port->state->xmit;
134 int count;
135
136 if (port->x_char) {
137 UART_PUT_CHAR(port, port->x_char);
138 port->icount.tx++;
139 port->x_char = 0;
140 return;
141 }
142
143 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
144 apbuart_stop_tx(port);
145 return;
146 }
147
148 /* amba: fill FIFO */
149 count = port->fifosize >> 1;
150 do {
151 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
152 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
153 port->icount.tx++;
154 if (uart_circ_empty(xmit))
155 break;
156 } while (--count > 0);
157
158 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
159 uart_write_wakeup(port);
160
161 if (uart_circ_empty(xmit))
162 apbuart_stop_tx(port);
163}
164
165static irqreturn_t apbuart_int(int irq, void *dev_id)
166{
167 struct uart_port *port = dev_id;
168 unsigned int status;
169
170 spin_lock(&port->lock);
171
172 status = UART_GET_STATUS(port);
173 if (status & UART_STATUS_DR)
174 apbuart_rx_chars(port);
175 if (status & UART_STATUS_THE)
176 apbuart_tx_chars(port);
177
178 spin_unlock(&port->lock);
179
180 return IRQ_HANDLED;
181}
182
183static unsigned int apbuart_tx_empty(struct uart_port *port)
184{
185 unsigned int status = UART_GET_STATUS(port);
186 return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
187}
188
189static unsigned int apbuart_get_mctrl(struct uart_port *port)
190{
191 /* The GRLIB APBUART handles flow control in hardware */
192 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
193}
194
195static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
196{
197 /* The GRLIB APBUART handles flow control in hardware */
198}
199
200static void apbuart_break_ctl(struct uart_port *port, int break_state)
201{
202 /* We don't support sending break */
203}
204
205static int apbuart_startup(struct uart_port *port)
206{
207 int retval;
208 unsigned int cr;
209
210 /* Allocate the IRQ */
211 retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
212 if (retval)
213 return retval;
214
215 /* Finally, enable interrupts */
216 cr = UART_GET_CTRL(port);
217 UART_PUT_CTRL(port,
218 cr | UART_CTRL_RE | UART_CTRL_TE |
219 UART_CTRL_RI | UART_CTRL_TI);
220
221 return 0;
222}
223
224static void apbuart_shutdown(struct uart_port *port)
225{
226 unsigned int cr;
227
228 /* disable all interrupts, disable the port */
229 cr = UART_GET_CTRL(port);
230 UART_PUT_CTRL(port,
231 cr & ~(UART_CTRL_RE | UART_CTRL_TE |
232 UART_CTRL_RI | UART_CTRL_TI));
233
234 /* Free the interrupt */
235 free_irq(port->irq, port);
236}
237
238static void apbuart_set_termios(struct uart_port *port,
239 struct ktermios *termios, struct ktermios *old)
240{
241 unsigned int cr;
242 unsigned long flags;
243 unsigned int baud, quot;
244
245 /* Ask the core to calculate the divisor for us. */
246 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
247 if (baud == 0)
248 panic("invalid baudrate %i\n", port->uartclk / 16);
249
250 /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
251 quot = (uart_get_divisor(port, baud)) * 2;
252 cr = UART_GET_CTRL(port);
253 cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
254
255 if (termios->c_cflag & PARENB) {
256 cr |= UART_CTRL_PE;
257 if ((termios->c_cflag & PARODD))
258 cr |= UART_CTRL_PS;
259 }
260
261 /* Enable flow control. */
262 if (termios->c_cflag & CRTSCTS)
263 cr |= UART_CTRL_FL;
264
265 spin_lock_irqsave(&port->lock, flags);
266
267 /* Update the per-port timeout. */
268 uart_update_timeout(port, termios->c_cflag, baud);
269
270 port->read_status_mask = UART_STATUS_OE;
271 if (termios->c_iflag & INPCK)
272 port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
273
274 /* Characters to ignore */
275 port->ignore_status_mask = 0;
276 if (termios->c_iflag & IGNPAR)
277 port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
278
279 /* Ignore all characters if CREAD is not set. */
280 if ((termios->c_cflag & CREAD) == 0)
281 port->ignore_status_mask |= UART_DUMMY_RSR_RX;
282
283 /* Set baud rate */
284 quot -= 1;
285 UART_PUT_SCAL(port, quot);
286 UART_PUT_CTRL(port, cr);
287
288 spin_unlock_irqrestore(&port->lock, flags);
289}
290
291static const char *apbuart_type(struct uart_port *port)
292{
293 return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
294}
295
296static void apbuart_release_port(struct uart_port *port)
297{
298 release_mem_region(port->mapbase, 0x100);
299}
300
301static int apbuart_request_port(struct uart_port *port)
302{
303 return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
304 != NULL ? 0 : -EBUSY;
305 return 0;
306}
307
308/* Configure/autoconfigure the port */
309static void apbuart_config_port(struct uart_port *port, int flags)
310{
311 if (flags & UART_CONFIG_TYPE) {
312 port->type = PORT_APBUART;
313 apbuart_request_port(port);
314 }
315}
316
317/* Verify the new serial_struct (for TIOCSSERIAL) */
318static int apbuart_verify_port(struct uart_port *port,
319 struct serial_struct *ser)
320{
321 int ret = 0;
322 if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
323 ret = -EINVAL;
324 if (ser->irq < 0 || ser->irq >= NR_IRQS)
325 ret = -EINVAL;
326 if (ser->baud_base < 9600)
327 ret = -EINVAL;
328 return ret;
329}
330
331static struct uart_ops grlib_apbuart_ops = {
332 .tx_empty = apbuart_tx_empty,
333 .set_mctrl = apbuart_set_mctrl,
334 .get_mctrl = apbuart_get_mctrl,
335 .stop_tx = apbuart_stop_tx,
336 .start_tx = apbuart_start_tx,
337 .stop_rx = apbuart_stop_rx,
338 .enable_ms = apbuart_enable_ms,
339 .break_ctl = apbuart_break_ctl,
340 .startup = apbuart_startup,
341 .shutdown = apbuart_shutdown,
342 .set_termios = apbuart_set_termios,
343 .type = apbuart_type,
344 .release_port = apbuart_release_port,
345 .request_port = apbuart_request_port,
346 .config_port = apbuart_config_port,
347 .verify_port = apbuart_verify_port,
348};
349
350static struct uart_port grlib_apbuart_ports[UART_NR];
351static struct device_node *grlib_apbuart_nodes[UART_NR];
352
353static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
354{
355 int ctrl, loop = 0;
356 int status;
357 int fifosize;
358 unsigned long flags;
359
360 ctrl = UART_GET_CTRL(port);
361
362 /*
363 * Enable the transceiver and wait for it to be ready to send data.
364 * Clear interrupts so that this process will not be externally
365 * interrupted in the middle (which can cause the transceiver to
366 * drain prematurely).
367 */
368
369 local_irq_save(flags);
370
371 UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
372
373 while (!UART_TX_READY(UART_GET_STATUS(port)))
374 loop++;
375
376 /*
377 * Disable the transceiver so data isn't actually sent during the
378 * actual test.
379 */
380
381 UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
382
383 fifosize = 1;
384 UART_PUT_CHAR(port, 0);
385
386 /*
387 * So long as transmitting a character increments the tranceivier FIFO
388 * length the FIFO must be at least that big. These bytes will
389 * automatically drain off of the FIFO.
390 */
391
392 status = UART_GET_STATUS(port);
393 while (((status >> 20) & 0x3F) == fifosize) {
394 fifosize++;
395 UART_PUT_CHAR(port, 0);
396 status = UART_GET_STATUS(port);
397 }
398
399 fifosize--;
400
401 UART_PUT_CTRL(port, ctrl);
402 local_irq_restore(flags);
403
404 if (fifosize == 0)
405 fifosize = 1;
406
407 return fifosize;
408}
409
410static void apbuart_flush_fifo(struct uart_port *port)
411{
412 int i;
413
414 for (i = 0; i < port->fifosize; i++)
415 UART_GET_CHAR(port);
416}
417
418
419/* ======================================================================== */
420/* Console driver, if enabled */
421/* ======================================================================== */
422
423#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
424
425static void apbuart_console_putchar(struct uart_port *port, int ch)
426{
427 unsigned int status;
428 do {
429 status = UART_GET_STATUS(port);
430 } while (!UART_TX_READY(status));
431 UART_PUT_CHAR(port, ch);
432}
433
434static void
435apbuart_console_write(struct console *co, const char *s, unsigned int count)
436{
437 struct uart_port *port = &grlib_apbuart_ports[co->index];
438 unsigned int status, old_cr, new_cr;
439
440 /* First save the CR then disable the interrupts */
441 old_cr = UART_GET_CTRL(port);
442 new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
443 UART_PUT_CTRL(port, new_cr);
444
445 uart_console_write(port, s, count, apbuart_console_putchar);
446
447 /*
448 * Finally, wait for transmitter to become empty
449 * and restore the TCR
450 */
451 do {
452 status = UART_GET_STATUS(port);
453 } while (!UART_TX_READY(status));
454 UART_PUT_CTRL(port, old_cr);
455}
456
457static void __init
458apbuart_console_get_options(struct uart_port *port, int *baud,
459 int *parity, int *bits)
460{
461 if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
462
463 unsigned int quot, status;
464 status = UART_GET_STATUS(port);
465
466 *parity = 'n';
467 if (status & UART_CTRL_PE) {
468 if ((status & UART_CTRL_PS) == 0)
469 *parity = 'e';
470 else
471 *parity = 'o';
472 }
473
474 *bits = 8;
475 quot = UART_GET_SCAL(port) / 8;
476 *baud = port->uartclk / (16 * (quot + 1));
477 }
478}
479
480static int __init apbuart_console_setup(struct console *co, char *options)
481{
482 struct uart_port *port;
483 int baud = 38400;
484 int bits = 8;
485 int parity = 'n';
486 int flow = 'n';
487
488 pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
489 co, co->index, options);
490
491 /*
492 * Check whether an invalid uart number has been specified, and
493 * if so, search for the first available port that does have
494 * console support.
495 */
496 if (co->index >= grlib_apbuart_port_nr)
497 co->index = 0;
498
499 port = &grlib_apbuart_ports[co->index];
500
501 spin_lock_init(&port->lock);
502
503 if (options)
504 uart_parse_options(options, &baud, &parity, &bits, &flow);
505 else
506 apbuart_console_get_options(port, &baud, &parity, &bits);
507
508 return uart_set_options(port, co, baud, parity, bits, flow);
509}
510
511static struct uart_driver grlib_apbuart_driver;
512
513static struct console grlib_apbuart_console = {
514 .name = "ttyS",
515 .write = apbuart_console_write,
516 .device = uart_console_device,
517 .setup = apbuart_console_setup,
518 .flags = CON_PRINTBUFFER,
519 .index = -1,
520 .data = &grlib_apbuart_driver,
521};
522
523
524static int grlib_apbuart_configure(void);
525
526static int __init apbuart_console_init(void)
527{
528 if (grlib_apbuart_configure())
529 return -ENODEV;
530 register_console(&grlib_apbuart_console);
531 return 0;
532}
533
534console_initcall(apbuart_console_init);
535
536#define APBUART_CONSOLE (&grlib_apbuart_console)
537#else
538#define APBUART_CONSOLE NULL
539#endif
540
541static struct uart_driver grlib_apbuart_driver = {
542 .owner = THIS_MODULE,
543 .driver_name = "serial",
544 .dev_name = "ttyS",
545 .major = SERIAL_APBUART_MAJOR,
546 .minor = SERIAL_APBUART_MINOR,
547 .nr = UART_NR,
548 .cons = APBUART_CONSOLE,
549};
550
551
552/* ======================================================================== */
553/* OF Platform Driver */
554/* ======================================================================== */
555
556static int __devinit apbuart_probe(struct platform_device *op)
557{
558 int i;
559 struct uart_port *port = NULL;
560
561 for (i = 0; i < grlib_apbuart_port_nr; i++) {
562 if (op->dev.of_node == grlib_apbuart_nodes[i])
563 break;
564 }
565
566 port = &grlib_apbuart_ports[i];
567 port->dev = &op->dev;
568 port->irq = op->archdata.irqs[0];
569
570 uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
571
572 apbuart_flush_fifo((struct uart_port *) port);
573
574 printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
575 (unsigned long long) port->mapbase, port->irq);
576 return 0;
577}
578
579static struct of_device_id __initdata apbuart_match[] = {
580 {
581 .name = "GAISLER_APBUART",
582 },
583 {
584 .name = "01_00c",
585 },
586 {},
587};
588
589static struct platform_driver grlib_apbuart_of_driver = {
590 .probe = apbuart_probe,
591 .driver = {
592 .owner = THIS_MODULE,
593 .name = "grlib-apbuart",
594 .of_match_table = apbuart_match,
595 },
596};
597
598
599static int grlib_apbuart_configure(void)
600{
601 struct device_node *np;
602 int line = 0;
603
604 for_each_matching_node(np, apbuart_match) {
605 const int *ampopts;
606 const u32 *freq_hz;
607 const struct amba_prom_registers *regs;
608 struct uart_port *port;
609 unsigned long addr;
610
611 ampopts = of_get_property(np, "ampopts", NULL);
612 if (ampopts && (*ampopts == 0))
613 continue; /* Ignore if used by another OS instance */
614 regs = of_get_property(np, "reg", NULL);
615 /* Frequency of APB Bus is frequency of UART */
616 freq_hz = of_get_property(np, "freq", NULL);
617
618 if (!regs || !freq_hz || (*freq_hz == 0))
619 continue;
620
621 grlib_apbuart_nodes[line] = np;
622
623 addr = regs->phys_addr;
624
625 port = &grlib_apbuart_ports[line];
626
627 port->mapbase = addr;
628 port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
629 port->irq = 0;
630 port->iotype = UPIO_MEM;
631 port->ops = &grlib_apbuart_ops;
632 port->flags = UPF_BOOT_AUTOCONF;
633 port->line = line;
634 port->uartclk = *freq_hz;
635 port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
636 line++;
637
638 /* We support maximum UART_NR uarts ... */
639 if (line == UART_NR)
640 break;
641 }
642
643 grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
644 return line ? 0 : -ENODEV;
645}
646
647static int __init grlib_apbuart_init(void)
648{
649 int ret;
650
651 /* Find all APBUARTS in device the tree and initialize their ports */
652 ret = grlib_apbuart_configure();
653 if (ret)
654 return ret;
655
656 printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
657
658 ret = uart_register_driver(&grlib_apbuart_driver);
659
660 if (ret) {
661 printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
662 __FILE__, ret);
663 return ret;
664 }
665
666 ret = platform_driver_register(&grlib_apbuart_of_driver);
667 if (ret) {
668 printk(KERN_ERR
669 "%s: platform_driver_register failed (%i)\n",
670 __FILE__, ret);
671 uart_unregister_driver(&grlib_apbuart_driver);
672 return ret;
673 }
674
675 return ret;
676}
677
678static void __exit grlib_apbuart_exit(void)
679{
680 int i;
681
682 for (i = 0; i < grlib_apbuart_port_nr; i++)
683 uart_remove_one_port(&grlib_apbuart_driver,
684 &grlib_apbuart_ports[i]);
685
686 uart_unregister_driver(&grlib_apbuart_driver);
687 platform_driver_unregister(&grlib_apbuart_of_driver);
688}
689
690module_init(grlib_apbuart_init);
691module_exit(grlib_apbuart_exit);
692
693MODULE_AUTHOR("Aeroflex Gaisler AB");
694MODULE_DESCRIPTION("GRLIB APBUART serial driver");
695MODULE_VERSION("2.1");
696MODULE_LICENSE("GPL");
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 u8 ch;
126
127 uart_port_tx_limited(port, ch, port->fifosize >> 1,
128 true,
129 UART_PUT_CHAR(port, ch),
130 ({}));
131}
132
133static irqreturn_t apbuart_int(int irq, void *dev_id)
134{
135 struct uart_port *port = dev_id;
136 unsigned int status;
137
138 spin_lock(&port->lock);
139
140 status = UART_GET_STATUS(port);
141 if (status & UART_STATUS_DR)
142 apbuart_rx_chars(port);
143 if (status & UART_STATUS_THE)
144 apbuart_tx_chars(port);
145
146 spin_unlock(&port->lock);
147
148 return IRQ_HANDLED;
149}
150
151static unsigned int apbuart_tx_empty(struct uart_port *port)
152{
153 unsigned int status = UART_GET_STATUS(port);
154 return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
155}
156
157static unsigned int apbuart_get_mctrl(struct uart_port *port)
158{
159 /* The GRLIB APBUART handles flow control in hardware */
160 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
161}
162
163static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
164{
165 /* The GRLIB APBUART handles flow control in hardware */
166}
167
168static void apbuart_break_ctl(struct uart_port *port, int break_state)
169{
170 /* We don't support sending break */
171}
172
173static int apbuart_startup(struct uart_port *port)
174{
175 int retval;
176 unsigned int cr;
177
178 /* Allocate the IRQ */
179 retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
180 if (retval)
181 return retval;
182
183 /* Finally, enable interrupts */
184 cr = UART_GET_CTRL(port);
185 UART_PUT_CTRL(port,
186 cr | UART_CTRL_RE | UART_CTRL_TE |
187 UART_CTRL_RI | UART_CTRL_TI);
188
189 return 0;
190}
191
192static void apbuart_shutdown(struct uart_port *port)
193{
194 unsigned int cr;
195
196 /* disable all interrupts, disable the port */
197 cr = UART_GET_CTRL(port);
198 UART_PUT_CTRL(port,
199 cr & ~(UART_CTRL_RE | UART_CTRL_TE |
200 UART_CTRL_RI | UART_CTRL_TI));
201
202 /* Free the interrupt */
203 free_irq(port->irq, port);
204}
205
206static void apbuart_set_termios(struct uart_port *port,
207 struct ktermios *termios, const struct ktermios *old)
208{
209 unsigned int cr;
210 unsigned long flags;
211 unsigned int baud, quot;
212
213 /* Ask the core to calculate the divisor for us. */
214 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
215 if (baud == 0)
216 panic("invalid baudrate %i\n", port->uartclk / 16);
217
218 /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
219 quot = (uart_get_divisor(port, baud)) * 2;
220 cr = UART_GET_CTRL(port);
221 cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
222
223 if (termios->c_cflag & PARENB) {
224 cr |= UART_CTRL_PE;
225 if ((termios->c_cflag & PARODD))
226 cr |= UART_CTRL_PS;
227 }
228
229 /* Enable flow control. */
230 if (termios->c_cflag & CRTSCTS)
231 cr |= UART_CTRL_FL;
232
233 spin_lock_irqsave(&port->lock, flags);
234
235 /* Update the per-port timeout. */
236 uart_update_timeout(port, termios->c_cflag, baud);
237
238 port->read_status_mask = UART_STATUS_OE;
239 if (termios->c_iflag & INPCK)
240 port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
241
242 /* Characters to ignore */
243 port->ignore_status_mask = 0;
244 if (termios->c_iflag & IGNPAR)
245 port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
246
247 /* Ignore all characters if CREAD is not set. */
248 if ((termios->c_cflag & CREAD) == 0)
249 port->ignore_status_mask |= UART_DUMMY_RSR_RX;
250
251 /* Set baud rate */
252 quot -= 1;
253 UART_PUT_SCAL(port, quot);
254 UART_PUT_CTRL(port, cr);
255
256 spin_unlock_irqrestore(&port->lock, flags);
257}
258
259static const char *apbuart_type(struct uart_port *port)
260{
261 return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
262}
263
264static void apbuart_release_port(struct uart_port *port)
265{
266 release_mem_region(port->mapbase, 0x100);
267}
268
269static int apbuart_request_port(struct uart_port *port)
270{
271 return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
272 != NULL ? 0 : -EBUSY;
273 return 0;
274}
275
276/* Configure/autoconfigure the port */
277static void apbuart_config_port(struct uart_port *port, int flags)
278{
279 if (flags & UART_CONFIG_TYPE) {
280 port->type = PORT_APBUART;
281 apbuart_request_port(port);
282 }
283}
284
285/* Verify the new serial_struct (for TIOCSSERIAL) */
286static int apbuart_verify_port(struct uart_port *port,
287 struct serial_struct *ser)
288{
289 int ret = 0;
290 if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
291 ret = -EINVAL;
292 if (ser->irq < 0 || ser->irq >= NR_IRQS)
293 ret = -EINVAL;
294 if (ser->baud_base < 9600)
295 ret = -EINVAL;
296 return ret;
297}
298
299static const struct uart_ops grlib_apbuart_ops = {
300 .tx_empty = apbuart_tx_empty,
301 .set_mctrl = apbuart_set_mctrl,
302 .get_mctrl = apbuart_get_mctrl,
303 .stop_tx = apbuart_stop_tx,
304 .start_tx = apbuart_start_tx,
305 .stop_rx = apbuart_stop_rx,
306 .break_ctl = apbuart_break_ctl,
307 .startup = apbuart_startup,
308 .shutdown = apbuart_shutdown,
309 .set_termios = apbuart_set_termios,
310 .type = apbuart_type,
311 .release_port = apbuart_release_port,
312 .request_port = apbuart_request_port,
313 .config_port = apbuart_config_port,
314 .verify_port = apbuart_verify_port,
315};
316
317static struct uart_port grlib_apbuart_ports[UART_NR];
318static struct device_node *grlib_apbuart_nodes[UART_NR];
319
320static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
321{
322 int ctrl, loop = 0;
323 int status;
324 int fifosize;
325 unsigned long flags;
326
327 ctrl = UART_GET_CTRL(port);
328
329 /*
330 * Enable the transceiver and wait for it to be ready to send data.
331 * Clear interrupts so that this process will not be externally
332 * interrupted in the middle (which can cause the transceiver to
333 * drain prematurely).
334 */
335
336 local_irq_save(flags);
337
338 UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
339
340 while (!UART_TX_READY(UART_GET_STATUS(port)))
341 loop++;
342
343 /*
344 * Disable the transceiver so data isn't actually sent during the
345 * actual test.
346 */
347
348 UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
349
350 fifosize = 1;
351 UART_PUT_CHAR(port, 0);
352
353 /*
354 * So long as transmitting a character increments the tranceivier FIFO
355 * length the FIFO must be at least that big. These bytes will
356 * automatically drain off of the FIFO.
357 */
358
359 status = UART_GET_STATUS(port);
360 while (((status >> 20) & 0x3F) == fifosize) {
361 fifosize++;
362 UART_PUT_CHAR(port, 0);
363 status = UART_GET_STATUS(port);
364 }
365
366 fifosize--;
367
368 UART_PUT_CTRL(port, ctrl);
369 local_irq_restore(flags);
370
371 if (fifosize == 0)
372 fifosize = 1;
373
374 return fifosize;
375}
376
377static void apbuart_flush_fifo(struct uart_port *port)
378{
379 int i;
380
381 for (i = 0; i < port->fifosize; i++)
382 UART_GET_CHAR(port);
383}
384
385
386/* ======================================================================== */
387/* Console driver, if enabled */
388/* ======================================================================== */
389
390#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
391
392static void apbuart_console_putchar(struct uart_port *port, unsigned char ch)
393{
394 unsigned int status;
395 do {
396 status = UART_GET_STATUS(port);
397 } while (!UART_TX_READY(status));
398 UART_PUT_CHAR(port, ch);
399}
400
401static void
402apbuart_console_write(struct console *co, const char *s, unsigned int count)
403{
404 struct uart_port *port = &grlib_apbuart_ports[co->index];
405 unsigned int status, old_cr, new_cr;
406
407 /* First save the CR then disable the interrupts */
408 old_cr = UART_GET_CTRL(port);
409 new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
410 UART_PUT_CTRL(port, new_cr);
411
412 uart_console_write(port, s, count, apbuart_console_putchar);
413
414 /*
415 * Finally, wait for transmitter to become empty
416 * and restore the TCR
417 */
418 do {
419 status = UART_GET_STATUS(port);
420 } while (!UART_TX_READY(status));
421 UART_PUT_CTRL(port, old_cr);
422}
423
424static void __init
425apbuart_console_get_options(struct uart_port *port, int *baud,
426 int *parity, int *bits)
427{
428 if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
429
430 unsigned int quot, status;
431 status = UART_GET_STATUS(port);
432
433 *parity = 'n';
434 if (status & UART_CTRL_PE) {
435 if ((status & UART_CTRL_PS) == 0)
436 *parity = 'e';
437 else
438 *parity = 'o';
439 }
440
441 *bits = 8;
442 quot = UART_GET_SCAL(port) / 8;
443 *baud = port->uartclk / (16 * (quot + 1));
444 }
445}
446
447static int __init apbuart_console_setup(struct console *co, char *options)
448{
449 struct uart_port *port;
450 int baud = 38400;
451 int bits = 8;
452 int parity = 'n';
453 int flow = 'n';
454
455 pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
456 co, co->index, options);
457
458 /*
459 * Check whether an invalid uart number has been specified, and
460 * if so, search for the first available port that does have
461 * console support.
462 */
463 if (co->index >= grlib_apbuart_port_nr)
464 co->index = 0;
465
466 port = &grlib_apbuart_ports[co->index];
467
468 spin_lock_init(&port->lock);
469
470 if (options)
471 uart_parse_options(options, &baud, &parity, &bits, &flow);
472 else
473 apbuart_console_get_options(port, &baud, &parity, &bits);
474
475 return uart_set_options(port, co, baud, parity, bits, flow);
476}
477
478static struct uart_driver grlib_apbuart_driver;
479
480static struct console grlib_apbuart_console = {
481 .name = "ttyS",
482 .write = apbuart_console_write,
483 .device = uart_console_device,
484 .setup = apbuart_console_setup,
485 .flags = CON_PRINTBUFFER,
486 .index = -1,
487 .data = &grlib_apbuart_driver,
488};
489
490
491static int grlib_apbuart_configure(void);
492
493static int __init apbuart_console_init(void)
494{
495 if (grlib_apbuart_configure())
496 return -ENODEV;
497 register_console(&grlib_apbuart_console);
498 return 0;
499}
500
501console_initcall(apbuart_console_init);
502
503#define APBUART_CONSOLE (&grlib_apbuart_console)
504#else
505#define APBUART_CONSOLE NULL
506#endif
507
508static struct uart_driver grlib_apbuart_driver = {
509 .owner = THIS_MODULE,
510 .driver_name = "serial",
511 .dev_name = "ttyS",
512 .major = SERIAL_APBUART_MAJOR,
513 .minor = SERIAL_APBUART_MINOR,
514 .nr = UART_NR,
515 .cons = APBUART_CONSOLE,
516};
517
518
519/* ======================================================================== */
520/* OF Platform Driver */
521/* ======================================================================== */
522
523static int apbuart_probe(struct platform_device *op)
524{
525 int i;
526 struct uart_port *port = NULL;
527
528 for (i = 0; i < grlib_apbuart_port_nr; i++) {
529 if (op->dev.of_node == grlib_apbuart_nodes[i])
530 break;
531 }
532
533 port = &grlib_apbuart_ports[i];
534 port->dev = &op->dev;
535 port->irq = op->archdata.irqs[0];
536
537 uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
538
539 apbuart_flush_fifo((struct uart_port *) port);
540
541 printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
542 (unsigned long long) port->mapbase, port->irq);
543 return 0;
544}
545
546static const struct of_device_id apbuart_match[] = {
547 {
548 .name = "GAISLER_APBUART",
549 },
550 {
551 .name = "01_00c",
552 },
553 {},
554};
555MODULE_DEVICE_TABLE(of, apbuart_match);
556
557static struct platform_driver grlib_apbuart_of_driver = {
558 .probe = apbuart_probe,
559 .driver = {
560 .name = "grlib-apbuart",
561 .of_match_table = apbuart_match,
562 },
563};
564
565
566static int __init grlib_apbuart_configure(void)
567{
568 struct device_node *np;
569 int line = 0;
570
571 for_each_matching_node(np, apbuart_match) {
572 const int *ampopts;
573 const u32 *freq_hz;
574 const struct amba_prom_registers *regs;
575 struct uart_port *port;
576 unsigned long addr;
577
578 ampopts = of_get_property(np, "ampopts", NULL);
579 if (ampopts && (*ampopts == 0))
580 continue; /* Ignore if used by another OS instance */
581 regs = of_get_property(np, "reg", NULL);
582 /* Frequency of APB Bus is frequency of UART */
583 freq_hz = of_get_property(np, "freq", NULL);
584
585 if (!regs || !freq_hz || (*freq_hz == 0))
586 continue;
587
588 grlib_apbuart_nodes[line] = np;
589
590 addr = regs->phys_addr;
591
592 port = &grlib_apbuart_ports[line];
593
594 port->mapbase = addr;
595 port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
596 port->irq = 0;
597 port->iotype = UPIO_MEM;
598 port->ops = &grlib_apbuart_ops;
599 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE);
600 port->flags = UPF_BOOT_AUTOCONF;
601 port->line = line;
602 port->uartclk = *freq_hz;
603 port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
604 line++;
605
606 /* We support maximum UART_NR uarts ... */
607 if (line == UART_NR)
608 break;
609 }
610
611 grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
612 return line ? 0 : -ENODEV;
613}
614
615static int __init grlib_apbuart_init(void)
616{
617 int ret;
618
619 /* Find all APBUARTS in device the tree and initialize their ports */
620 ret = grlib_apbuart_configure();
621 if (ret)
622 return ret;
623
624 printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
625
626 ret = uart_register_driver(&grlib_apbuart_driver);
627
628 if (ret) {
629 printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
630 __FILE__, ret);
631 return ret;
632 }
633
634 ret = platform_driver_register(&grlib_apbuart_of_driver);
635 if (ret) {
636 printk(KERN_ERR
637 "%s: platform_driver_register failed (%i)\n",
638 __FILE__, ret);
639 uart_unregister_driver(&grlib_apbuart_driver);
640 return ret;
641 }
642
643 return ret;
644}
645
646static void __exit grlib_apbuart_exit(void)
647{
648 int i;
649
650 for (i = 0; i < grlib_apbuart_port_nr; i++)
651 uart_remove_one_port(&grlib_apbuart_driver,
652 &grlib_apbuart_ports[i]);
653
654 uart_unregister_driver(&grlib_apbuart_driver);
655 platform_driver_unregister(&grlib_apbuart_of_driver);
656}
657
658module_init(grlib_apbuart_init);
659module_exit(grlib_apbuart_exit);
660
661MODULE_AUTHOR("Aeroflex Gaisler AB");
662MODULE_DESCRIPTION("GRLIB APBUART serial driver");
663MODULE_VERSION("2.1");
664MODULE_LICENSE("GPL");