Loading...
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/platform_device.h>
26#include <linux/io.h>
27#include <linux/serial_core.h>
28#include <asm/irq.h>
29
30#include "apbuart.h"
31
32#define SERIAL_APBUART_MAJOR TTY_MAJOR
33#define SERIAL_APBUART_MINOR 64
34#define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
35
36static void apbuart_tx_chars(struct uart_port *port);
37
38static void apbuart_stop_tx(struct uart_port *port)
39{
40 unsigned int cr;
41
42 cr = UART_GET_CTRL(port);
43 cr &= ~UART_CTRL_TI;
44 UART_PUT_CTRL(port, cr);
45}
46
47static void apbuart_start_tx(struct uart_port *port)
48{
49 unsigned int cr;
50
51 cr = UART_GET_CTRL(port);
52 cr |= UART_CTRL_TI;
53 UART_PUT_CTRL(port, cr);
54
55 if (UART_GET_STATUS(port) & UART_STATUS_THE)
56 apbuart_tx_chars(port);
57}
58
59static void apbuart_stop_rx(struct uart_port *port)
60{
61 unsigned int cr;
62
63 cr = UART_GET_CTRL(port);
64 cr &= ~(UART_CTRL_RI);
65 UART_PUT_CTRL(port, cr);
66}
67
68static void apbuart_rx_chars(struct uart_port *port)
69{
70 unsigned int status, rsr;
71 unsigned int max_chars = port->fifosize;
72 u8 ch, flag;
73
74 status = UART_GET_STATUS(port);
75
76 while (UART_RX_DATA(status) && (max_chars--)) {
77
78 ch = UART_GET_CHAR(port);
79 flag = TTY_NORMAL;
80
81 port->icount.rx++;
82
83 rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
84 UART_PUT_STATUS(port, 0);
85 if (rsr & UART_STATUS_ERR) {
86
87 if (rsr & UART_STATUS_BR) {
88 rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
89 port->icount.brk++;
90 if (uart_handle_break(port))
91 goto ignore_char;
92 } else if (rsr & UART_STATUS_PE) {
93 port->icount.parity++;
94 } else if (rsr & UART_STATUS_FE) {
95 port->icount.frame++;
96 }
97 if (rsr & UART_STATUS_OE)
98 port->icount.overrun++;
99
100 rsr &= port->read_status_mask;
101
102 if (rsr & UART_STATUS_PE)
103 flag = TTY_PARITY;
104 else if (rsr & UART_STATUS_FE)
105 flag = TTY_FRAME;
106 }
107
108 if (uart_handle_sysrq_char(port, ch))
109 goto ignore_char;
110
111 uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
112
113
114 ignore_char:
115 status = UART_GET_STATUS(port);
116 }
117
118 tty_flip_buffer_push(&port->state->port);
119}
120
121static void apbuart_tx_chars(struct uart_port *port)
122{
123 u8 ch;
124
125 uart_port_tx_limited(port, ch, port->fifosize,
126 true,
127 UART_PUT_CHAR(port, ch),
128 ({}));
129}
130
131static irqreturn_t apbuart_int(int irq, void *dev_id)
132{
133 struct uart_port *port = dev_id;
134 unsigned int status;
135
136 uart_port_lock(port);
137
138 status = UART_GET_STATUS(port);
139 if (status & UART_STATUS_DR)
140 apbuart_rx_chars(port);
141 if (status & UART_STATUS_THE)
142 apbuart_tx_chars(port);
143
144 uart_port_unlock(port);
145
146 return IRQ_HANDLED;
147}
148
149static unsigned int apbuart_tx_empty(struct uart_port *port)
150{
151 unsigned int status = UART_GET_STATUS(port);
152 return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
153}
154
155static unsigned int apbuart_get_mctrl(struct uart_port *port)
156{
157 /* The GRLIB APBUART handles flow control in hardware */
158 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
159}
160
161static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
162{
163 /* The GRLIB APBUART handles flow control in hardware */
164}
165
166static void apbuart_break_ctl(struct uart_port *port, int break_state)
167{
168 /* We don't support sending break */
169}
170
171static int apbuart_startup(struct uart_port *port)
172{
173 int retval;
174 unsigned int cr;
175
176 /* Allocate the IRQ */
177 retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
178 if (retval)
179 return retval;
180
181 /* Finally, enable interrupts */
182 cr = UART_GET_CTRL(port);
183 UART_PUT_CTRL(port,
184 cr | UART_CTRL_RE | UART_CTRL_TE |
185 UART_CTRL_RI | UART_CTRL_TI);
186
187 return 0;
188}
189
190static void apbuart_shutdown(struct uart_port *port)
191{
192 unsigned int cr;
193
194 /* disable all interrupts, disable the port */
195 cr = UART_GET_CTRL(port);
196 UART_PUT_CTRL(port,
197 cr & ~(UART_CTRL_RE | UART_CTRL_TE |
198 UART_CTRL_RI | UART_CTRL_TI));
199
200 /* Free the interrupt */
201 free_irq(port->irq, port);
202}
203
204static void apbuart_set_termios(struct uart_port *port,
205 struct ktermios *termios, const struct ktermios *old)
206{
207 unsigned int cr;
208 unsigned long flags;
209 unsigned int baud, quot;
210
211 /* Ask the core to calculate the divisor for us. */
212 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
213 if (baud == 0)
214 panic("invalid baudrate %i\n", port->uartclk / 16);
215
216 /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
217 quot = (uart_get_divisor(port, baud)) * 2;
218 cr = UART_GET_CTRL(port);
219 cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
220
221 if (termios->c_cflag & PARENB) {
222 cr |= UART_CTRL_PE;
223 if ((termios->c_cflag & PARODD))
224 cr |= UART_CTRL_PS;
225 }
226
227 /* Enable flow control. */
228 if (termios->c_cflag & CRTSCTS)
229 cr |= UART_CTRL_FL;
230
231 uart_port_lock_irqsave(port, &flags);
232
233 /* Update the per-port timeout. */
234 uart_update_timeout(port, termios->c_cflag, baud);
235
236 port->read_status_mask = UART_STATUS_OE;
237 if (termios->c_iflag & INPCK)
238 port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
239
240 /* Characters to ignore */
241 port->ignore_status_mask = 0;
242 if (termios->c_iflag & IGNPAR)
243 port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
244
245 /* Ignore all characters if CREAD is not set. */
246 if ((termios->c_cflag & CREAD) == 0)
247 port->ignore_status_mask |= UART_DUMMY_RSR_RX;
248
249 /* Set baud rate */
250 quot -= 1;
251 UART_PUT_SCAL(port, quot);
252 UART_PUT_CTRL(port, cr);
253
254 uart_port_unlock_irqrestore(port, flags);
255}
256
257static const char *apbuart_type(struct uart_port *port)
258{
259 return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
260}
261
262static void apbuart_release_port(struct uart_port *port)
263{
264 release_mem_region(port->mapbase, 0x100);
265}
266
267static int apbuart_request_port(struct uart_port *port)
268{
269 return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
270 != NULL ? 0 : -EBUSY;
271 return 0;
272}
273
274/* Configure/autoconfigure the port */
275static void apbuart_config_port(struct uart_port *port, int flags)
276{
277 if (flags & UART_CONFIG_TYPE) {
278 port->type = PORT_APBUART;
279 apbuart_request_port(port);
280 }
281}
282
283/* Verify the new serial_struct (for TIOCSSERIAL) */
284static int apbuart_verify_port(struct uart_port *port,
285 struct serial_struct *ser)
286{
287 int ret = 0;
288 if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
289 ret = -EINVAL;
290 if (ser->irq < 0 || ser->irq >= NR_IRQS)
291 ret = -EINVAL;
292 if (ser->baud_base < 9600)
293 ret = -EINVAL;
294 return ret;
295}
296
297static const struct uart_ops grlib_apbuart_ops = {
298 .tx_empty = apbuart_tx_empty,
299 .set_mctrl = apbuart_set_mctrl,
300 .get_mctrl = apbuart_get_mctrl,
301 .stop_tx = apbuart_stop_tx,
302 .start_tx = apbuart_start_tx,
303 .stop_rx = apbuart_stop_rx,
304 .break_ctl = apbuart_break_ctl,
305 .startup = apbuart_startup,
306 .shutdown = apbuart_shutdown,
307 .set_termios = apbuart_set_termios,
308 .type = apbuart_type,
309 .release_port = apbuart_release_port,
310 .request_port = apbuart_request_port,
311 .config_port = apbuart_config_port,
312 .verify_port = apbuart_verify_port,
313};
314
315static struct uart_port grlib_apbuart_ports[UART_NR];
316static struct device_node *grlib_apbuart_nodes[UART_NR];
317
318static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
319{
320 int ctrl, loop = 0;
321 int status;
322 int fifosize;
323 unsigned long flags;
324
325 ctrl = UART_GET_CTRL(port);
326
327 /*
328 * Enable the transceiver and wait for it to be ready to send data.
329 * Clear interrupts so that this process will not be externally
330 * interrupted in the middle (which can cause the transceiver to
331 * drain prematurely).
332 */
333
334 local_irq_save(flags);
335
336 UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
337
338 while (!UART_TX_READY(UART_GET_STATUS(port)))
339 loop++;
340
341 /*
342 * Disable the transceiver so data isn't actually sent during the
343 * actual test.
344 */
345
346 UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
347
348 fifosize = 1;
349 UART_PUT_CHAR(port, 0);
350
351 /*
352 * So long as transmitting a character increments the tranceivier FIFO
353 * length the FIFO must be at least that big. These bytes will
354 * automatically drain off of the FIFO.
355 */
356
357 status = UART_GET_STATUS(port);
358 while (((status >> 20) & 0x3F) == fifosize) {
359 fifosize++;
360 UART_PUT_CHAR(port, 0);
361 status = UART_GET_STATUS(port);
362 }
363
364 fifosize--;
365
366 UART_PUT_CTRL(port, ctrl);
367 local_irq_restore(flags);
368
369 if (fifosize == 0)
370 fifosize = 1;
371
372 return fifosize;
373}
374
375static void apbuart_flush_fifo(struct uart_port *port)
376{
377 int i;
378
379 for (i = 0; i < port->fifosize; i++)
380 UART_GET_CHAR(port);
381}
382
383
384/* ======================================================================== */
385/* Console driver, if enabled */
386/* ======================================================================== */
387
388#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
389
390static void apbuart_console_putchar(struct uart_port *port, unsigned char ch)
391{
392 unsigned int status;
393 do {
394 status = UART_GET_STATUS(port);
395 } while (!UART_TX_READY(status));
396 UART_PUT_CHAR(port, ch);
397}
398
399static void
400apbuart_console_write(struct console *co, const char *s, unsigned int count)
401{
402 struct uart_port *port = &grlib_apbuart_ports[co->index];
403 unsigned int status, old_cr, new_cr;
404
405 /* First save the CR then disable the interrupts */
406 old_cr = UART_GET_CTRL(port);
407 new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
408 UART_PUT_CTRL(port, new_cr);
409
410 uart_console_write(port, s, count, apbuart_console_putchar);
411
412 /*
413 * Finally, wait for transmitter to become empty
414 * and restore the TCR
415 */
416 do {
417 status = UART_GET_STATUS(port);
418 } while (!UART_TX_READY(status));
419 UART_PUT_CTRL(port, old_cr);
420}
421
422static void __init
423apbuart_console_get_options(struct uart_port *port, int *baud,
424 int *parity, int *bits)
425{
426 if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
427
428 unsigned int quot, status;
429 status = UART_GET_STATUS(port);
430
431 *parity = 'n';
432 if (status & UART_CTRL_PE) {
433 if ((status & UART_CTRL_PS) == 0)
434 *parity = 'e';
435 else
436 *parity = 'o';
437 }
438
439 *bits = 8;
440 quot = UART_GET_SCAL(port) / 8;
441 *baud = port->uartclk / (16 * (quot + 1));
442 }
443}
444
445static int __init apbuart_console_setup(struct console *co, char *options)
446{
447 struct uart_port *port;
448 int baud = 38400;
449 int bits = 8;
450 int parity = 'n';
451 int flow = 'n';
452
453 pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
454 co, co->index, options);
455
456 /*
457 * Check whether an invalid uart number has been specified, and
458 * if so, search for the first available port that does have
459 * console support.
460 */
461 if (co->index >= grlib_apbuart_port_nr)
462 co->index = 0;
463
464 port = &grlib_apbuart_ports[co->index];
465
466 spin_lock_init(&port->lock);
467
468 if (options)
469 uart_parse_options(options, &baud, &parity, &bits, &flow);
470 else
471 apbuart_console_get_options(port, &baud, &parity, &bits);
472
473 return uart_set_options(port, co, baud, parity, bits, flow);
474}
475
476static struct uart_driver grlib_apbuart_driver;
477
478static struct console grlib_apbuart_console = {
479 .name = "ttyS",
480 .write = apbuart_console_write,
481 .device = uart_console_device,
482 .setup = apbuart_console_setup,
483 .flags = CON_PRINTBUFFER,
484 .index = -1,
485 .data = &grlib_apbuart_driver,
486};
487
488
489static int grlib_apbuart_configure(void);
490
491static int __init apbuart_console_init(void)
492{
493 if (grlib_apbuart_configure())
494 return -ENODEV;
495 register_console(&grlib_apbuart_console);
496 return 0;
497}
498
499console_initcall(apbuart_console_init);
500
501#define APBUART_CONSOLE (&grlib_apbuart_console)
502#else
503#define APBUART_CONSOLE NULL
504#endif
505
506static struct uart_driver grlib_apbuart_driver = {
507 .owner = THIS_MODULE,
508 .driver_name = "serial",
509 .dev_name = "ttyS",
510 .major = SERIAL_APBUART_MAJOR,
511 .minor = SERIAL_APBUART_MINOR,
512 .nr = UART_NR,
513 .cons = APBUART_CONSOLE,
514};
515
516
517/* ======================================================================== */
518/* OF Platform Driver */
519/* ======================================================================== */
520
521static int apbuart_probe(struct platform_device *op)
522{
523 int i;
524 struct uart_port *port = NULL;
525
526 for (i = 0; i < grlib_apbuart_port_nr; i++) {
527 if (op->dev.of_node == grlib_apbuart_nodes[i])
528 break;
529 }
530
531 port = &grlib_apbuart_ports[i];
532 port->dev = &op->dev;
533 port->irq = op->archdata.irqs[0];
534
535 uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
536
537 apbuart_flush_fifo((struct uart_port *) port);
538
539 printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
540 (unsigned long long) port->mapbase, port->irq);
541 return 0;
542}
543
544static const struct of_device_id apbuart_match[] = {
545 {
546 .name = "GAISLER_APBUART",
547 },
548 {
549 .name = "01_00c",
550 },
551 {},
552};
553MODULE_DEVICE_TABLE(of, apbuart_match);
554
555static struct platform_driver grlib_apbuart_of_driver = {
556 .probe = apbuart_probe,
557 .driver = {
558 .name = "grlib-apbuart",
559 .of_match_table = apbuart_match,
560 },
561};
562
563
564static int __init grlib_apbuart_configure(void)
565{
566 struct device_node *np;
567 int line = 0;
568
569 for_each_matching_node(np, apbuart_match) {
570 const int *ampopts;
571 const u32 *freq_hz;
572 const struct amba_prom_registers *regs;
573 struct uart_port *port;
574 unsigned long addr;
575
576 ampopts = of_get_property(np, "ampopts", NULL);
577 if (ampopts && (*ampopts == 0))
578 continue; /* Ignore if used by another OS instance */
579 regs = of_get_property(np, "reg", NULL);
580 /* Frequency of APB Bus is frequency of UART */
581 freq_hz = of_get_property(np, "freq", NULL);
582
583 if (!regs || !freq_hz || (*freq_hz == 0))
584 continue;
585
586 grlib_apbuart_nodes[line] = np;
587
588 addr = regs->phys_addr;
589
590 port = &grlib_apbuart_ports[line];
591
592 port->mapbase = addr;
593 port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
594 port->irq = 0;
595 port->iotype = UPIO_MEM;
596 port->ops = &grlib_apbuart_ops;
597 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE);
598 port->flags = UPF_BOOT_AUTOCONF;
599 port->line = line;
600 port->uartclk = *freq_hz;
601 port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
602 line++;
603
604 /* We support maximum UART_NR uarts ... */
605 if (line == UART_NR)
606 break;
607 }
608
609 grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
610 return line ? 0 : -ENODEV;
611}
612
613static int __init grlib_apbuart_init(void)
614{
615 int ret;
616
617 /* Find all APBUARTS in device the tree and initialize their ports */
618 ret = grlib_apbuart_configure();
619 if (ret)
620 return ret;
621
622 printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
623
624 ret = uart_register_driver(&grlib_apbuart_driver);
625
626 if (ret) {
627 printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
628 __FILE__, ret);
629 return ret;
630 }
631
632 ret = platform_driver_register(&grlib_apbuart_of_driver);
633 if (ret) {
634 printk(KERN_ERR
635 "%s: platform_driver_register failed (%i)\n",
636 __FILE__, ret);
637 uart_unregister_driver(&grlib_apbuart_driver);
638 return ret;
639 }
640
641 return ret;
642}
643
644static void __exit grlib_apbuart_exit(void)
645{
646 int i;
647
648 for (i = 0; i < grlib_apbuart_port_nr; i++)
649 uart_remove_one_port(&grlib_apbuart_driver,
650 &grlib_apbuart_ports[i]);
651
652 uart_unregister_driver(&grlib_apbuart_driver);
653 platform_driver_unregister(&grlib_apbuart_of_driver);
654}
655
656module_init(grlib_apbuart_init);
657module_exit(grlib_apbuart_exit);
658
659MODULE_AUTHOR("Aeroflex Gaisler AB");
660MODULE_DESCRIPTION("GRLIB APBUART serial driver");
661MODULE_VERSION("2.1");
662MODULE_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_enable_ms(struct uart_port *port)
75{
76 /* No modem status change interrupts for APBUART */
77}
78
79static void apbuart_rx_chars(struct uart_port *port)
80{
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 spin_unlock(&port->lock);
129 tty_flip_buffer_push(&port->state->port);
130 spin_lock(&port->lock);
131}
132
133static void apbuart_tx_chars(struct uart_port *port)
134{
135 struct circ_buf *xmit = &port->state->xmit;
136 int count;
137
138 if (port->x_char) {
139 UART_PUT_CHAR(port, port->x_char);
140 port->icount.tx++;
141 port->x_char = 0;
142 return;
143 }
144
145 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
146 apbuart_stop_tx(port);
147 return;
148 }
149
150 /* amba: fill FIFO */
151 count = port->fifosize >> 1;
152 do {
153 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
154 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
155 port->icount.tx++;
156 if (uart_circ_empty(xmit))
157 break;
158 } while (--count > 0);
159
160 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
161 uart_write_wakeup(port);
162
163 if (uart_circ_empty(xmit))
164 apbuart_stop_tx(port);
165}
166
167static irqreturn_t apbuart_int(int irq, void *dev_id)
168{
169 struct uart_port *port = dev_id;
170 unsigned int status;
171
172 spin_lock(&port->lock);
173
174 status = UART_GET_STATUS(port);
175 if (status & UART_STATUS_DR)
176 apbuart_rx_chars(port);
177 if (status & UART_STATUS_THE)
178 apbuart_tx_chars(port);
179
180 spin_unlock(&port->lock);
181
182 return IRQ_HANDLED;
183}
184
185static unsigned int apbuart_tx_empty(struct uart_port *port)
186{
187 unsigned int status = UART_GET_STATUS(port);
188 return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
189}
190
191static unsigned int apbuart_get_mctrl(struct uart_port *port)
192{
193 /* The GRLIB APBUART handles flow control in hardware */
194 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
195}
196
197static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
198{
199 /* The GRLIB APBUART handles flow control in hardware */
200}
201
202static void apbuart_break_ctl(struct uart_port *port, int break_state)
203{
204 /* We don't support sending break */
205}
206
207static int apbuart_startup(struct uart_port *port)
208{
209 int retval;
210 unsigned int cr;
211
212 /* Allocate the IRQ */
213 retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
214 if (retval)
215 return retval;
216
217 /* Finally, enable interrupts */
218 cr = UART_GET_CTRL(port);
219 UART_PUT_CTRL(port,
220 cr | UART_CTRL_RE | UART_CTRL_TE |
221 UART_CTRL_RI | UART_CTRL_TI);
222
223 return 0;
224}
225
226static void apbuart_shutdown(struct uart_port *port)
227{
228 unsigned int cr;
229
230 /* disable all interrupts, disable the port */
231 cr = UART_GET_CTRL(port);
232 UART_PUT_CTRL(port,
233 cr & ~(UART_CTRL_RE | UART_CTRL_TE |
234 UART_CTRL_RI | UART_CTRL_TI));
235
236 /* Free the interrupt */
237 free_irq(port->irq, port);
238}
239
240static void apbuart_set_termios(struct uart_port *port,
241 struct ktermios *termios, struct ktermios *old)
242{
243 unsigned int cr;
244 unsigned long flags;
245 unsigned int baud, quot;
246
247 /* Ask the core to calculate the divisor for us. */
248 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
249 if (baud == 0)
250 panic("invalid baudrate %i\n", port->uartclk / 16);
251
252 /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
253 quot = (uart_get_divisor(port, baud)) * 2;
254 cr = UART_GET_CTRL(port);
255 cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
256
257 if (termios->c_cflag & PARENB) {
258 cr |= UART_CTRL_PE;
259 if ((termios->c_cflag & PARODD))
260 cr |= UART_CTRL_PS;
261 }
262
263 /* Enable flow control. */
264 if (termios->c_cflag & CRTSCTS)
265 cr |= UART_CTRL_FL;
266
267 spin_lock_irqsave(&port->lock, flags);
268
269 /* Update the per-port timeout. */
270 uart_update_timeout(port, termios->c_cflag, baud);
271
272 port->read_status_mask = UART_STATUS_OE;
273 if (termios->c_iflag & INPCK)
274 port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
275
276 /* Characters to ignore */
277 port->ignore_status_mask = 0;
278 if (termios->c_iflag & IGNPAR)
279 port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
280
281 /* Ignore all characters if CREAD is not set. */
282 if ((termios->c_cflag & CREAD) == 0)
283 port->ignore_status_mask |= UART_DUMMY_RSR_RX;
284
285 /* Set baud rate */
286 quot -= 1;
287 UART_PUT_SCAL(port, quot);
288 UART_PUT_CTRL(port, cr);
289
290 spin_unlock_irqrestore(&port->lock, flags);
291}
292
293static const char *apbuart_type(struct uart_port *port)
294{
295 return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
296}
297
298static void apbuart_release_port(struct uart_port *port)
299{
300 release_mem_region(port->mapbase, 0x100);
301}
302
303static int apbuart_request_port(struct uart_port *port)
304{
305 return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
306 != NULL ? 0 : -EBUSY;
307 return 0;
308}
309
310/* Configure/autoconfigure the port */
311static void apbuart_config_port(struct uart_port *port, int flags)
312{
313 if (flags & UART_CONFIG_TYPE) {
314 port->type = PORT_APBUART;
315 apbuart_request_port(port);
316 }
317}
318
319/* Verify the new serial_struct (for TIOCSSERIAL) */
320static int apbuart_verify_port(struct uart_port *port,
321 struct serial_struct *ser)
322{
323 int ret = 0;
324 if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
325 ret = -EINVAL;
326 if (ser->irq < 0 || ser->irq >= NR_IRQS)
327 ret = -EINVAL;
328 if (ser->baud_base < 9600)
329 ret = -EINVAL;
330 return ret;
331}
332
333static struct uart_ops grlib_apbuart_ops = {
334 .tx_empty = apbuart_tx_empty,
335 .set_mctrl = apbuart_set_mctrl,
336 .get_mctrl = apbuart_get_mctrl,
337 .stop_tx = apbuart_stop_tx,
338 .start_tx = apbuart_start_tx,
339 .stop_rx = apbuart_stop_rx,
340 .enable_ms = apbuart_enable_ms,
341 .break_ctl = apbuart_break_ctl,
342 .startup = apbuart_startup,
343 .shutdown = apbuart_shutdown,
344 .set_termios = apbuart_set_termios,
345 .type = apbuart_type,
346 .release_port = apbuart_release_port,
347 .request_port = apbuart_request_port,
348 .config_port = apbuart_config_port,
349 .verify_port = apbuart_verify_port,
350};
351
352static struct uart_port grlib_apbuart_ports[UART_NR];
353static struct device_node *grlib_apbuart_nodes[UART_NR];
354
355static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
356{
357 int ctrl, loop = 0;
358 int status;
359 int fifosize;
360 unsigned long flags;
361
362 ctrl = UART_GET_CTRL(port);
363
364 /*
365 * Enable the transceiver and wait for it to be ready to send data.
366 * Clear interrupts so that this process will not be externally
367 * interrupted in the middle (which can cause the transceiver to
368 * drain prematurely).
369 */
370
371 local_irq_save(flags);
372
373 UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
374
375 while (!UART_TX_READY(UART_GET_STATUS(port)))
376 loop++;
377
378 /*
379 * Disable the transceiver so data isn't actually sent during the
380 * actual test.
381 */
382
383 UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
384
385 fifosize = 1;
386 UART_PUT_CHAR(port, 0);
387
388 /*
389 * So long as transmitting a character increments the tranceivier FIFO
390 * length the FIFO must be at least that big. These bytes will
391 * automatically drain off of the FIFO.
392 */
393
394 status = UART_GET_STATUS(port);
395 while (((status >> 20) & 0x3F) == fifosize) {
396 fifosize++;
397 UART_PUT_CHAR(port, 0);
398 status = UART_GET_STATUS(port);
399 }
400
401 fifosize--;
402
403 UART_PUT_CTRL(port, ctrl);
404 local_irq_restore(flags);
405
406 if (fifosize == 0)
407 fifosize = 1;
408
409 return fifosize;
410}
411
412static void apbuart_flush_fifo(struct uart_port *port)
413{
414 int i;
415
416 for (i = 0; i < port->fifosize; i++)
417 UART_GET_CHAR(port);
418}
419
420
421/* ======================================================================== */
422/* Console driver, if enabled */
423/* ======================================================================== */
424
425#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
426
427static void apbuart_console_putchar(struct uart_port *port, int ch)
428{
429 unsigned int status;
430 do {
431 status = UART_GET_STATUS(port);
432 } while (!UART_TX_READY(status));
433 UART_PUT_CHAR(port, ch);
434}
435
436static void
437apbuart_console_write(struct console *co, const char *s, unsigned int count)
438{
439 struct uart_port *port = &grlib_apbuart_ports[co->index];
440 unsigned int status, old_cr, new_cr;
441
442 /* First save the CR then disable the interrupts */
443 old_cr = UART_GET_CTRL(port);
444 new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
445 UART_PUT_CTRL(port, new_cr);
446
447 uart_console_write(port, s, count, apbuart_console_putchar);
448
449 /*
450 * Finally, wait for transmitter to become empty
451 * and restore the TCR
452 */
453 do {
454 status = UART_GET_STATUS(port);
455 } while (!UART_TX_READY(status));
456 UART_PUT_CTRL(port, old_cr);
457}
458
459static void __init
460apbuart_console_get_options(struct uart_port *port, int *baud,
461 int *parity, int *bits)
462{
463 if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
464
465 unsigned int quot, status;
466 status = UART_GET_STATUS(port);
467
468 *parity = 'n';
469 if (status & UART_CTRL_PE) {
470 if ((status & UART_CTRL_PS) == 0)
471 *parity = 'e';
472 else
473 *parity = 'o';
474 }
475
476 *bits = 8;
477 quot = UART_GET_SCAL(port) / 8;
478 *baud = port->uartclk / (16 * (quot + 1));
479 }
480}
481
482static int __init apbuart_console_setup(struct console *co, char *options)
483{
484 struct uart_port *port;
485 int baud = 38400;
486 int bits = 8;
487 int parity = 'n';
488 int flow = 'n';
489
490 pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
491 co, co->index, options);
492
493 /*
494 * Check whether an invalid uart number has been specified, and
495 * if so, search for the first available port that does have
496 * console support.
497 */
498 if (co->index >= grlib_apbuart_port_nr)
499 co->index = 0;
500
501 port = &grlib_apbuart_ports[co->index];
502
503 spin_lock_init(&port->lock);
504
505 if (options)
506 uart_parse_options(options, &baud, &parity, &bits, &flow);
507 else
508 apbuart_console_get_options(port, &baud, &parity, &bits);
509
510 return uart_set_options(port, co, baud, parity, bits, flow);
511}
512
513static struct uart_driver grlib_apbuart_driver;
514
515static struct console grlib_apbuart_console = {
516 .name = "ttyS",
517 .write = apbuart_console_write,
518 .device = uart_console_device,
519 .setup = apbuart_console_setup,
520 .flags = CON_PRINTBUFFER,
521 .index = -1,
522 .data = &grlib_apbuart_driver,
523};
524
525
526static int grlib_apbuart_configure(void);
527
528static int __init apbuart_console_init(void)
529{
530 if (grlib_apbuart_configure())
531 return -ENODEV;
532 register_console(&grlib_apbuart_console);
533 return 0;
534}
535
536console_initcall(apbuart_console_init);
537
538#define APBUART_CONSOLE (&grlib_apbuart_console)
539#else
540#define APBUART_CONSOLE NULL
541#endif
542
543static struct uart_driver grlib_apbuart_driver = {
544 .owner = THIS_MODULE,
545 .driver_name = "serial",
546 .dev_name = "ttyS",
547 .major = SERIAL_APBUART_MAJOR,
548 .minor = SERIAL_APBUART_MINOR,
549 .nr = UART_NR,
550 .cons = APBUART_CONSOLE,
551};
552
553
554/* ======================================================================== */
555/* OF Platform Driver */
556/* ======================================================================== */
557
558static int apbuart_probe(struct platform_device *op)
559{
560 int i;
561 struct uart_port *port = NULL;
562
563 for (i = 0; i < grlib_apbuart_port_nr; i++) {
564 if (op->dev.of_node == grlib_apbuart_nodes[i])
565 break;
566 }
567
568 port = &grlib_apbuart_ports[i];
569 port->dev = &op->dev;
570 port->irq = op->archdata.irqs[0];
571
572 uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
573
574 apbuart_flush_fifo((struct uart_port *) port);
575
576 printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
577 (unsigned long long) port->mapbase, port->irq);
578 return 0;
579}
580
581static struct of_device_id apbuart_match[] = {
582 {
583 .name = "GAISLER_APBUART",
584 },
585 {
586 .name = "01_00c",
587 },
588 {},
589};
590
591static struct platform_driver grlib_apbuart_of_driver = {
592 .probe = apbuart_probe,
593 .driver = {
594 .owner = THIS_MODULE,
595 .name = "grlib-apbuart",
596 .of_match_table = apbuart_match,
597 },
598};
599
600
601static int __init grlib_apbuart_configure(void)
602{
603 struct device_node *np;
604 int line = 0;
605
606 for_each_matching_node(np, apbuart_match) {
607 const int *ampopts;
608 const u32 *freq_hz;
609 const struct amba_prom_registers *regs;
610 struct uart_port *port;
611 unsigned long addr;
612
613 ampopts = of_get_property(np, "ampopts", NULL);
614 if (ampopts && (*ampopts == 0))
615 continue; /* Ignore if used by another OS instance */
616 regs = of_get_property(np, "reg", NULL);
617 /* Frequency of APB Bus is frequency of UART */
618 freq_hz = of_get_property(np, "freq", NULL);
619
620 if (!regs || !freq_hz || (*freq_hz == 0))
621 continue;
622
623 grlib_apbuart_nodes[line] = np;
624
625 addr = regs->phys_addr;
626
627 port = &grlib_apbuart_ports[line];
628
629 port->mapbase = addr;
630 port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
631 port->irq = 0;
632 port->iotype = UPIO_MEM;
633 port->ops = &grlib_apbuart_ops;
634 port->flags = UPF_BOOT_AUTOCONF;
635 port->line = line;
636 port->uartclk = *freq_hz;
637 port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
638 line++;
639
640 /* We support maximum UART_NR uarts ... */
641 if (line == UART_NR)
642 break;
643 }
644
645 grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
646 return line ? 0 : -ENODEV;
647}
648
649static int __init grlib_apbuart_init(void)
650{
651 int ret;
652
653 /* Find all APBUARTS in device the tree and initialize their ports */
654 ret = grlib_apbuart_configure();
655 if (ret)
656 return ret;
657
658 printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
659
660 ret = uart_register_driver(&grlib_apbuart_driver);
661
662 if (ret) {
663 printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
664 __FILE__, ret);
665 return ret;
666 }
667
668 ret = platform_driver_register(&grlib_apbuart_of_driver);
669 if (ret) {
670 printk(KERN_ERR
671 "%s: platform_driver_register failed (%i)\n",
672 __FILE__, ret);
673 uart_unregister_driver(&grlib_apbuart_driver);
674 return ret;
675 }
676
677 return ret;
678}
679
680static void __exit grlib_apbuart_exit(void)
681{
682 int i;
683
684 for (i = 0; i < grlib_apbuart_port_nr; i++)
685 uart_remove_one_port(&grlib_apbuart_driver,
686 &grlib_apbuart_ports[i]);
687
688 uart_unregister_driver(&grlib_apbuart_driver);
689 platform_driver_unregister(&grlib_apbuart_of_driver);
690}
691
692module_init(grlib_apbuart_init);
693module_exit(grlib_apbuart_exit);
694
695MODULE_AUTHOR("Aeroflex Gaisler AB");
696MODULE_DESCRIPTION("GRLIB APBUART serial driver");
697MODULE_VERSION("2.1");
698MODULE_LICENSE("GPL");