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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#if defined(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
15#define SUPPORT_SYSRQ
16#endif
17
18#include <linux/module.h>
19#include <linux/tty.h>
20#include <linux/tty_flip.h>
21#include <linux/ioport.h>
22#include <linux/init.h>
23#include <linux/serial.h>
24#include <linux/console.h>
25#include <linux/sysrq.h>
26#include <linux/kthread.h>
27#include <linux/device.h>
28#include <linux/of.h>
29#include <linux/of_device.h>
30#include <linux/of_platform.h>
31#include <linux/of_irq.h>
32#include <linux/platform_device.h>
33#include <linux/io.h>
34#include <linux/serial_core.h>
35#include <asm/irq.h>
36
37#include "apbuart.h"
38
39#define SERIAL_APBUART_MAJOR TTY_MAJOR
40#define SERIAL_APBUART_MINOR 64
41#define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
42
43static void apbuart_tx_chars(struct uart_port *port);
44
45static void apbuart_stop_tx(struct uart_port *port)
46{
47 unsigned int cr;
48
49 cr = UART_GET_CTRL(port);
50 cr &= ~UART_CTRL_TI;
51 UART_PUT_CTRL(port, cr);
52}
53
54static void apbuart_start_tx(struct uart_port *port)
55{
56 unsigned int cr;
57
58 cr = UART_GET_CTRL(port);
59 cr |= UART_CTRL_TI;
60 UART_PUT_CTRL(port, cr);
61
62 if (UART_GET_STATUS(port) & UART_STATUS_THE)
63 apbuart_tx_chars(port);
64}
65
66static void apbuart_stop_rx(struct uart_port *port)
67{
68 unsigned int cr;
69
70 cr = UART_GET_CTRL(port);
71 cr &= ~(UART_CTRL_RI);
72 UART_PUT_CTRL(port, cr);
73}
74
75static void apbuart_rx_chars(struct uart_port *port)
76{
77 unsigned int status, ch, rsr, flag;
78 unsigned int max_chars = port->fifosize;
79
80 status = UART_GET_STATUS(port);
81
82 while (UART_RX_DATA(status) && (max_chars--)) {
83
84 ch = UART_GET_CHAR(port);
85 flag = TTY_NORMAL;
86
87 port->icount.rx++;
88
89 rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
90 UART_PUT_STATUS(port, 0);
91 if (rsr & UART_STATUS_ERR) {
92
93 if (rsr & UART_STATUS_BR) {
94 rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
95 port->icount.brk++;
96 if (uart_handle_break(port))
97 goto ignore_char;
98 } else if (rsr & UART_STATUS_PE) {
99 port->icount.parity++;
100 } else if (rsr & UART_STATUS_FE) {
101 port->icount.frame++;
102 }
103 if (rsr & UART_STATUS_OE)
104 port->icount.overrun++;
105
106 rsr &= port->read_status_mask;
107
108 if (rsr & UART_STATUS_PE)
109 flag = TTY_PARITY;
110 else if (rsr & UART_STATUS_FE)
111 flag = TTY_FRAME;
112 }
113
114 if (uart_handle_sysrq_char(port, ch))
115 goto ignore_char;
116
117 uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
118
119
120 ignore_char:
121 status = UART_GET_STATUS(port);
122 }
123
124 spin_unlock(&port->lock);
125 tty_flip_buffer_push(&port->state->port);
126 spin_lock(&port->lock);
127}
128
129static void apbuart_tx_chars(struct uart_port *port)
130{
131 struct circ_buf *xmit = &port->state->xmit;
132 int count;
133
134 if (port->x_char) {
135 UART_PUT_CHAR(port, port->x_char);
136 port->icount.tx++;
137 port->x_char = 0;
138 return;
139 }
140
141 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
142 apbuart_stop_tx(port);
143 return;
144 }
145
146 /* amba: fill FIFO */
147 count = port->fifosize >> 1;
148 do {
149 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
150 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
151 port->icount.tx++;
152 if (uart_circ_empty(xmit))
153 break;
154 } while (--count > 0);
155
156 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
157 uart_write_wakeup(port);
158
159 if (uart_circ_empty(xmit))
160 apbuart_stop_tx(port);
161}
162
163static irqreturn_t apbuart_int(int irq, void *dev_id)
164{
165 struct uart_port *port = dev_id;
166 unsigned int status;
167
168 spin_lock(&port->lock);
169
170 status = UART_GET_STATUS(port);
171 if (status & UART_STATUS_DR)
172 apbuart_rx_chars(port);
173 if (status & UART_STATUS_THE)
174 apbuart_tx_chars(port);
175
176 spin_unlock(&port->lock);
177
178 return IRQ_HANDLED;
179}
180
181static unsigned int apbuart_tx_empty(struct uart_port *port)
182{
183 unsigned int status = UART_GET_STATUS(port);
184 return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
185}
186
187static unsigned int apbuart_get_mctrl(struct uart_port *port)
188{
189 /* The GRLIB APBUART handles flow control in hardware */
190 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
191}
192
193static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
194{
195 /* The GRLIB APBUART handles flow control in hardware */
196}
197
198static void apbuart_break_ctl(struct uart_port *port, int break_state)
199{
200 /* We don't support sending break */
201}
202
203static int apbuart_startup(struct uart_port *port)
204{
205 int retval;
206 unsigned int cr;
207
208 /* Allocate the IRQ */
209 retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
210 if (retval)
211 return retval;
212
213 /* Finally, enable interrupts */
214 cr = UART_GET_CTRL(port);
215 UART_PUT_CTRL(port,
216 cr | UART_CTRL_RE | UART_CTRL_TE |
217 UART_CTRL_RI | UART_CTRL_TI);
218
219 return 0;
220}
221
222static void apbuart_shutdown(struct uart_port *port)
223{
224 unsigned int cr;
225
226 /* disable all interrupts, disable the port */
227 cr = UART_GET_CTRL(port);
228 UART_PUT_CTRL(port,
229 cr & ~(UART_CTRL_RE | UART_CTRL_TE |
230 UART_CTRL_RI | UART_CTRL_TI));
231
232 /* Free the interrupt */
233 free_irq(port->irq, port);
234}
235
236static void apbuart_set_termios(struct uart_port *port,
237 struct ktermios *termios, struct ktermios *old)
238{
239 unsigned int cr;
240 unsigned long flags;
241 unsigned int baud, quot;
242
243 /* Ask the core to calculate the divisor for us. */
244 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
245 if (baud == 0)
246 panic("invalid baudrate %i\n", port->uartclk / 16);
247
248 /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
249 quot = (uart_get_divisor(port, baud)) * 2;
250 cr = UART_GET_CTRL(port);
251 cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
252
253 if (termios->c_cflag & PARENB) {
254 cr |= UART_CTRL_PE;
255 if ((termios->c_cflag & PARODD))
256 cr |= UART_CTRL_PS;
257 }
258
259 /* Enable flow control. */
260 if (termios->c_cflag & CRTSCTS)
261 cr |= UART_CTRL_FL;
262
263 spin_lock_irqsave(&port->lock, flags);
264
265 /* Update the per-port timeout. */
266 uart_update_timeout(port, termios->c_cflag, baud);
267
268 port->read_status_mask = UART_STATUS_OE;
269 if (termios->c_iflag & INPCK)
270 port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
271
272 /* Characters to ignore */
273 port->ignore_status_mask = 0;
274 if (termios->c_iflag & IGNPAR)
275 port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
276
277 /* Ignore all characters if CREAD is not set. */
278 if ((termios->c_cflag & CREAD) == 0)
279 port->ignore_status_mask |= UART_DUMMY_RSR_RX;
280
281 /* Set baud rate */
282 quot -= 1;
283 UART_PUT_SCAL(port, quot);
284 UART_PUT_CTRL(port, cr);
285
286 spin_unlock_irqrestore(&port->lock, flags);
287}
288
289static const char *apbuart_type(struct uart_port *port)
290{
291 return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
292}
293
294static void apbuart_release_port(struct uart_port *port)
295{
296 release_mem_region(port->mapbase, 0x100);
297}
298
299static int apbuart_request_port(struct uart_port *port)
300{
301 return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
302 != NULL ? 0 : -EBUSY;
303 return 0;
304}
305
306/* Configure/autoconfigure the port */
307static void apbuart_config_port(struct uart_port *port, int flags)
308{
309 if (flags & UART_CONFIG_TYPE) {
310 port->type = PORT_APBUART;
311 apbuart_request_port(port);
312 }
313}
314
315/* Verify the new serial_struct (for TIOCSSERIAL) */
316static int apbuart_verify_port(struct uart_port *port,
317 struct serial_struct *ser)
318{
319 int ret = 0;
320 if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
321 ret = -EINVAL;
322 if (ser->irq < 0 || ser->irq >= NR_IRQS)
323 ret = -EINVAL;
324 if (ser->baud_base < 9600)
325 ret = -EINVAL;
326 return ret;
327}
328
329static const struct uart_ops grlib_apbuart_ops = {
330 .tx_empty = apbuart_tx_empty,
331 .set_mctrl = apbuart_set_mctrl,
332 .get_mctrl = apbuart_get_mctrl,
333 .stop_tx = apbuart_stop_tx,
334 .start_tx = apbuart_start_tx,
335 .stop_rx = apbuart_stop_rx,
336 .break_ctl = apbuart_break_ctl,
337 .startup = apbuart_startup,
338 .shutdown = apbuart_shutdown,
339 .set_termios = apbuart_set_termios,
340 .type = apbuart_type,
341 .release_port = apbuart_release_port,
342 .request_port = apbuart_request_port,
343 .config_port = apbuart_config_port,
344 .verify_port = apbuart_verify_port,
345};
346
347static struct uart_port grlib_apbuart_ports[UART_NR];
348static struct device_node *grlib_apbuart_nodes[UART_NR];
349
350static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
351{
352 int ctrl, loop = 0;
353 int status;
354 int fifosize;
355 unsigned long flags;
356
357 ctrl = UART_GET_CTRL(port);
358
359 /*
360 * Enable the transceiver and wait for it to be ready to send data.
361 * Clear interrupts so that this process will not be externally
362 * interrupted in the middle (which can cause the transceiver to
363 * drain prematurely).
364 */
365
366 local_irq_save(flags);
367
368 UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
369
370 while (!UART_TX_READY(UART_GET_STATUS(port)))
371 loop++;
372
373 /*
374 * Disable the transceiver so data isn't actually sent during the
375 * actual test.
376 */
377
378 UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
379
380 fifosize = 1;
381 UART_PUT_CHAR(port, 0);
382
383 /*
384 * So long as transmitting a character increments the tranceivier FIFO
385 * length the FIFO must be at least that big. These bytes will
386 * automatically drain off of the FIFO.
387 */
388
389 status = UART_GET_STATUS(port);
390 while (((status >> 20) & 0x3F) == fifosize) {
391 fifosize++;
392 UART_PUT_CHAR(port, 0);
393 status = UART_GET_STATUS(port);
394 }
395
396 fifosize--;
397
398 UART_PUT_CTRL(port, ctrl);
399 local_irq_restore(flags);
400
401 if (fifosize == 0)
402 fifosize = 1;
403
404 return fifosize;
405}
406
407static void apbuart_flush_fifo(struct uart_port *port)
408{
409 int i;
410
411 for (i = 0; i < port->fifosize; i++)
412 UART_GET_CHAR(port);
413}
414
415
416/* ======================================================================== */
417/* Console driver, if enabled */
418/* ======================================================================== */
419
420#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
421
422static void apbuart_console_putchar(struct uart_port *port, int ch)
423{
424 unsigned int status;
425 do {
426 status = UART_GET_STATUS(port);
427 } while (!UART_TX_READY(status));
428 UART_PUT_CHAR(port, ch);
429}
430
431static void
432apbuart_console_write(struct console *co, const char *s, unsigned int count)
433{
434 struct uart_port *port = &grlib_apbuart_ports[co->index];
435 unsigned int status, old_cr, new_cr;
436
437 /* First save the CR then disable the interrupts */
438 old_cr = UART_GET_CTRL(port);
439 new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
440 UART_PUT_CTRL(port, new_cr);
441
442 uart_console_write(port, s, count, apbuart_console_putchar);
443
444 /*
445 * Finally, wait for transmitter to become empty
446 * and restore the TCR
447 */
448 do {
449 status = UART_GET_STATUS(port);
450 } while (!UART_TX_READY(status));
451 UART_PUT_CTRL(port, old_cr);
452}
453
454static void __init
455apbuart_console_get_options(struct uart_port *port, int *baud,
456 int *parity, int *bits)
457{
458 if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
459
460 unsigned int quot, status;
461 status = UART_GET_STATUS(port);
462
463 *parity = 'n';
464 if (status & UART_CTRL_PE) {
465 if ((status & UART_CTRL_PS) == 0)
466 *parity = 'e';
467 else
468 *parity = 'o';
469 }
470
471 *bits = 8;
472 quot = UART_GET_SCAL(port) / 8;
473 *baud = port->uartclk / (16 * (quot + 1));
474 }
475}
476
477static int __init apbuart_console_setup(struct console *co, char *options)
478{
479 struct uart_port *port;
480 int baud = 38400;
481 int bits = 8;
482 int parity = 'n';
483 int flow = 'n';
484
485 pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
486 co, co->index, options);
487
488 /*
489 * Check whether an invalid uart number has been specified, and
490 * if so, search for the first available port that does have
491 * console support.
492 */
493 if (co->index >= grlib_apbuart_port_nr)
494 co->index = 0;
495
496 port = &grlib_apbuart_ports[co->index];
497
498 spin_lock_init(&port->lock);
499
500 if (options)
501 uart_parse_options(options, &baud, &parity, &bits, &flow);
502 else
503 apbuart_console_get_options(port, &baud, &parity, &bits);
504
505 return uart_set_options(port, co, baud, parity, bits, flow);
506}
507
508static struct uart_driver grlib_apbuart_driver;
509
510static struct console grlib_apbuart_console = {
511 .name = "ttyS",
512 .write = apbuart_console_write,
513 .device = uart_console_device,
514 .setup = apbuart_console_setup,
515 .flags = CON_PRINTBUFFER,
516 .index = -1,
517 .data = &grlib_apbuart_driver,
518};
519
520
521static int grlib_apbuart_configure(void);
522
523static int __init apbuart_console_init(void)
524{
525 if (grlib_apbuart_configure())
526 return -ENODEV;
527 register_console(&grlib_apbuart_console);
528 return 0;
529}
530
531console_initcall(apbuart_console_init);
532
533#define APBUART_CONSOLE (&grlib_apbuart_console)
534#else
535#define APBUART_CONSOLE NULL
536#endif
537
538static struct uart_driver grlib_apbuart_driver = {
539 .owner = THIS_MODULE,
540 .driver_name = "serial",
541 .dev_name = "ttyS",
542 .major = SERIAL_APBUART_MAJOR,
543 .minor = SERIAL_APBUART_MINOR,
544 .nr = UART_NR,
545 .cons = APBUART_CONSOLE,
546};
547
548
549/* ======================================================================== */
550/* OF Platform Driver */
551/* ======================================================================== */
552
553static int apbuart_probe(struct platform_device *op)
554{
555 int i;
556 struct uart_port *port = NULL;
557
558 for (i = 0; i < grlib_apbuart_port_nr; i++) {
559 if (op->dev.of_node == grlib_apbuart_nodes[i])
560 break;
561 }
562
563 port = &grlib_apbuart_ports[i];
564 port->dev = &op->dev;
565 port->irq = op->archdata.irqs[0];
566
567 uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
568
569 apbuart_flush_fifo((struct uart_port *) port);
570
571 printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
572 (unsigned long long) port->mapbase, port->irq);
573 return 0;
574}
575
576static const struct of_device_id apbuart_match[] = {
577 {
578 .name = "GAISLER_APBUART",
579 },
580 {
581 .name = "01_00c",
582 },
583 {},
584};
585MODULE_DEVICE_TABLE(of, apbuart_match);
586
587static struct platform_driver grlib_apbuart_of_driver = {
588 .probe = apbuart_probe,
589 .driver = {
590 .name = "grlib-apbuart",
591 .of_match_table = apbuart_match,
592 },
593};
594
595
596static int __init grlib_apbuart_configure(void)
597{
598 struct device_node *np;
599 int line = 0;
600
601 for_each_matching_node(np, apbuart_match) {
602 const int *ampopts;
603 const u32 *freq_hz;
604 const struct amba_prom_registers *regs;
605 struct uart_port *port;
606 unsigned long addr;
607
608 ampopts = of_get_property(np, "ampopts", NULL);
609 if (ampopts && (*ampopts == 0))
610 continue; /* Ignore if used by another OS instance */
611 regs = of_get_property(np, "reg", NULL);
612 /* Frequency of APB Bus is frequency of UART */
613 freq_hz = of_get_property(np, "freq", NULL);
614
615 if (!regs || !freq_hz || (*freq_hz == 0))
616 continue;
617
618 grlib_apbuart_nodes[line] = np;
619
620 addr = regs->phys_addr;
621
622 port = &grlib_apbuart_ports[line];
623
624 port->mapbase = addr;
625 port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
626 port->irq = 0;
627 port->iotype = UPIO_MEM;
628 port->ops = &grlib_apbuart_ops;
629 port->flags = UPF_BOOT_AUTOCONF;
630 port->line = line;
631 port->uartclk = *freq_hz;
632 port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
633 line++;
634
635 /* We support maximum UART_NR uarts ... */
636 if (line == UART_NR)
637 break;
638 }
639
640 grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
641 return line ? 0 : -ENODEV;
642}
643
644static int __init grlib_apbuart_init(void)
645{
646 int ret;
647
648 /* Find all APBUARTS in device the tree and initialize their ports */
649 ret = grlib_apbuart_configure();
650 if (ret)
651 return ret;
652
653 printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
654
655 ret = uart_register_driver(&grlib_apbuart_driver);
656
657 if (ret) {
658 printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
659 __FILE__, ret);
660 return ret;
661 }
662
663 ret = platform_driver_register(&grlib_apbuart_of_driver);
664 if (ret) {
665 printk(KERN_ERR
666 "%s: platform_driver_register failed (%i)\n",
667 __FILE__, ret);
668 uart_unregister_driver(&grlib_apbuart_driver);
669 return ret;
670 }
671
672 return ret;
673}
674
675static void __exit grlib_apbuart_exit(void)
676{
677 int i;
678
679 for (i = 0; i < grlib_apbuart_port_nr; i++)
680 uart_remove_one_port(&grlib_apbuart_driver,
681 &grlib_apbuart_ports[i]);
682
683 uart_unregister_driver(&grlib_apbuart_driver);
684 platform_driver_unregister(&grlib_apbuart_of_driver);
685}
686
687module_init(grlib_apbuart_init);
688module_exit(grlib_apbuart_exit);
689
690MODULE_AUTHOR("Aeroflex Gaisler AB");
691MODULE_DESCRIPTION("GRLIB APBUART serial driver");
692MODULE_VERSION("2.1");
693MODULE_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#if defined(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
15#define SUPPORT_SYSRQ
16#endif
17
18#include <linux/module.h>
19#include <linux/tty.h>
20#include <linux/tty_flip.h>
21#include <linux/ioport.h>
22#include <linux/init.h>
23#include <linux/serial.h>
24#include <linux/console.h>
25#include <linux/sysrq.h>
26#include <linux/kthread.h>
27#include <linux/device.h>
28#include <linux/of.h>
29#include <linux/of_device.h>
30#include <linux/of_platform.h>
31#include <linux/of_irq.h>
32#include <linux/platform_device.h>
33#include <linux/io.h>
34#include <linux/serial_core.h>
35#include <asm/irq.h>
36
37#include "apbuart.h"
38
39#define SERIAL_APBUART_MAJOR TTY_MAJOR
40#define SERIAL_APBUART_MINOR 64
41#define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
42
43static void apbuart_tx_chars(struct uart_port *port);
44
45static void apbuart_stop_tx(struct uart_port *port)
46{
47 unsigned int cr;
48
49 cr = UART_GET_CTRL(port);
50 cr &= ~UART_CTRL_TI;
51 UART_PUT_CTRL(port, cr);
52}
53
54static void apbuart_start_tx(struct uart_port *port)
55{
56 unsigned int cr;
57
58 cr = UART_GET_CTRL(port);
59 cr |= UART_CTRL_TI;
60 UART_PUT_CTRL(port, cr);
61
62 if (UART_GET_STATUS(port) & UART_STATUS_THE)
63 apbuart_tx_chars(port);
64}
65
66static void apbuart_stop_rx(struct uart_port *port)
67{
68 unsigned int cr;
69
70 cr = UART_GET_CTRL(port);
71 cr &= ~(UART_CTRL_RI);
72 UART_PUT_CTRL(port, cr);
73}
74
75static void apbuart_rx_chars(struct uart_port *port)
76{
77 unsigned int status, ch, rsr, flag;
78 unsigned int max_chars = port->fifosize;
79
80 status = UART_GET_STATUS(port);
81
82 while (UART_RX_DATA(status) && (max_chars--)) {
83
84 ch = UART_GET_CHAR(port);
85 flag = TTY_NORMAL;
86
87 port->icount.rx++;
88
89 rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
90 UART_PUT_STATUS(port, 0);
91 if (rsr & UART_STATUS_ERR) {
92
93 if (rsr & UART_STATUS_BR) {
94 rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
95 port->icount.brk++;
96 if (uart_handle_break(port))
97 goto ignore_char;
98 } else if (rsr & UART_STATUS_PE) {
99 port->icount.parity++;
100 } else if (rsr & UART_STATUS_FE) {
101 port->icount.frame++;
102 }
103 if (rsr & UART_STATUS_OE)
104 port->icount.overrun++;
105
106 rsr &= port->read_status_mask;
107
108 if (rsr & UART_STATUS_PE)
109 flag = TTY_PARITY;
110 else if (rsr & UART_STATUS_FE)
111 flag = TTY_FRAME;
112 }
113
114 if (uart_handle_sysrq_char(port, ch))
115 goto ignore_char;
116
117 uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
118
119
120 ignore_char:
121 status = UART_GET_STATUS(port);
122 }
123
124 spin_unlock(&port->lock);
125 tty_flip_buffer_push(&port->state->port);
126 spin_lock(&port->lock);
127}
128
129static void apbuart_tx_chars(struct uart_port *port)
130{
131 struct circ_buf *xmit = &port->state->xmit;
132 int count;
133
134 if (port->x_char) {
135 UART_PUT_CHAR(port, port->x_char);
136 port->icount.tx++;
137 port->x_char = 0;
138 return;
139 }
140
141 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
142 apbuart_stop_tx(port);
143 return;
144 }
145
146 /* amba: fill FIFO */
147 count = port->fifosize >> 1;
148 do {
149 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
150 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
151 port->icount.tx++;
152 if (uart_circ_empty(xmit))
153 break;
154 } while (--count > 0);
155
156 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
157 uart_write_wakeup(port);
158
159 if (uart_circ_empty(xmit))
160 apbuart_stop_tx(port);
161}
162
163static irqreturn_t apbuart_int(int irq, void *dev_id)
164{
165 struct uart_port *port = dev_id;
166 unsigned int status;
167
168 spin_lock(&port->lock);
169
170 status = UART_GET_STATUS(port);
171 if (status & UART_STATUS_DR)
172 apbuart_rx_chars(port);
173 if (status & UART_STATUS_THE)
174 apbuart_tx_chars(port);
175
176 spin_unlock(&port->lock);
177
178 return IRQ_HANDLED;
179}
180
181static unsigned int apbuart_tx_empty(struct uart_port *port)
182{
183 unsigned int status = UART_GET_STATUS(port);
184 return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
185}
186
187static unsigned int apbuart_get_mctrl(struct uart_port *port)
188{
189 /* The GRLIB APBUART handles flow control in hardware */
190 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
191}
192
193static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
194{
195 /* The GRLIB APBUART handles flow control in hardware */
196}
197
198static void apbuart_break_ctl(struct uart_port *port, int break_state)
199{
200 /* We don't support sending break */
201}
202
203static int apbuart_startup(struct uart_port *port)
204{
205 int retval;
206 unsigned int cr;
207
208 /* Allocate the IRQ */
209 retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
210 if (retval)
211 return retval;
212
213 /* Finally, enable interrupts */
214 cr = UART_GET_CTRL(port);
215 UART_PUT_CTRL(port,
216 cr | UART_CTRL_RE | UART_CTRL_TE |
217 UART_CTRL_RI | UART_CTRL_TI);
218
219 return 0;
220}
221
222static void apbuart_shutdown(struct uart_port *port)
223{
224 unsigned int cr;
225
226 /* disable all interrupts, disable the port */
227 cr = UART_GET_CTRL(port);
228 UART_PUT_CTRL(port,
229 cr & ~(UART_CTRL_RE | UART_CTRL_TE |
230 UART_CTRL_RI | UART_CTRL_TI));
231
232 /* Free the interrupt */
233 free_irq(port->irq, port);
234}
235
236static void apbuart_set_termios(struct uart_port *port,
237 struct ktermios *termios, struct ktermios *old)
238{
239 unsigned int cr;
240 unsigned long flags;
241 unsigned int baud, quot;
242
243 /* Ask the core to calculate the divisor for us. */
244 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
245 if (baud == 0)
246 panic("invalid baudrate %i\n", port->uartclk / 16);
247
248 /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
249 quot = (uart_get_divisor(port, baud)) * 2;
250 cr = UART_GET_CTRL(port);
251 cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
252
253 if (termios->c_cflag & PARENB) {
254 cr |= UART_CTRL_PE;
255 if ((termios->c_cflag & PARODD))
256 cr |= UART_CTRL_PS;
257 }
258
259 /* Enable flow control. */
260 if (termios->c_cflag & CRTSCTS)
261 cr |= UART_CTRL_FL;
262
263 spin_lock_irqsave(&port->lock, flags);
264
265 /* Update the per-port timeout. */
266 uart_update_timeout(port, termios->c_cflag, baud);
267
268 port->read_status_mask = UART_STATUS_OE;
269 if (termios->c_iflag & INPCK)
270 port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
271
272 /* Characters to ignore */
273 port->ignore_status_mask = 0;
274 if (termios->c_iflag & IGNPAR)
275 port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
276
277 /* Ignore all characters if CREAD is not set. */
278 if ((termios->c_cflag & CREAD) == 0)
279 port->ignore_status_mask |= UART_DUMMY_RSR_RX;
280
281 /* Set baud rate */
282 quot -= 1;
283 UART_PUT_SCAL(port, quot);
284 UART_PUT_CTRL(port, cr);
285
286 spin_unlock_irqrestore(&port->lock, flags);
287}
288
289static const char *apbuart_type(struct uart_port *port)
290{
291 return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
292}
293
294static void apbuart_release_port(struct uart_port *port)
295{
296 release_mem_region(port->mapbase, 0x100);
297}
298
299static int apbuart_request_port(struct uart_port *port)
300{
301 return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
302 != NULL ? 0 : -EBUSY;
303 return 0;
304}
305
306/* Configure/autoconfigure the port */
307static void apbuart_config_port(struct uart_port *port, int flags)
308{
309 if (flags & UART_CONFIG_TYPE) {
310 port->type = PORT_APBUART;
311 apbuart_request_port(port);
312 }
313}
314
315/* Verify the new serial_struct (for TIOCSSERIAL) */
316static int apbuart_verify_port(struct uart_port *port,
317 struct serial_struct *ser)
318{
319 int ret = 0;
320 if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
321 ret = -EINVAL;
322 if (ser->irq < 0 || ser->irq >= NR_IRQS)
323 ret = -EINVAL;
324 if (ser->baud_base < 9600)
325 ret = -EINVAL;
326 return ret;
327}
328
329static const struct uart_ops grlib_apbuart_ops = {
330 .tx_empty = apbuart_tx_empty,
331 .set_mctrl = apbuart_set_mctrl,
332 .get_mctrl = apbuart_get_mctrl,
333 .stop_tx = apbuart_stop_tx,
334 .start_tx = apbuart_start_tx,
335 .stop_rx = apbuart_stop_rx,
336 .break_ctl = apbuart_break_ctl,
337 .startup = apbuart_startup,
338 .shutdown = apbuart_shutdown,
339 .set_termios = apbuart_set_termios,
340 .type = apbuart_type,
341 .release_port = apbuart_release_port,
342 .request_port = apbuart_request_port,
343 .config_port = apbuart_config_port,
344 .verify_port = apbuart_verify_port,
345};
346
347static struct uart_port grlib_apbuart_ports[UART_NR];
348static struct device_node *grlib_apbuart_nodes[UART_NR];
349
350static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
351{
352 int ctrl, loop = 0;
353 int status;
354 int fifosize;
355 unsigned long flags;
356
357 ctrl = UART_GET_CTRL(port);
358
359 /*
360 * Enable the transceiver and wait for it to be ready to send data.
361 * Clear interrupts so that this process will not be externally
362 * interrupted in the middle (which can cause the transceiver to
363 * drain prematurely).
364 */
365
366 local_irq_save(flags);
367
368 UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
369
370 while (!UART_TX_READY(UART_GET_STATUS(port)))
371 loop++;
372
373 /*
374 * Disable the transceiver so data isn't actually sent during the
375 * actual test.
376 */
377
378 UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
379
380 fifosize = 1;
381 UART_PUT_CHAR(port, 0);
382
383 /*
384 * So long as transmitting a character increments the tranceivier FIFO
385 * length the FIFO must be at least that big. These bytes will
386 * automatically drain off of the FIFO.
387 */
388
389 status = UART_GET_STATUS(port);
390 while (((status >> 20) & 0x3F) == fifosize) {
391 fifosize++;
392 UART_PUT_CHAR(port, 0);
393 status = UART_GET_STATUS(port);
394 }
395
396 fifosize--;
397
398 UART_PUT_CTRL(port, ctrl);
399 local_irq_restore(flags);
400
401 if (fifosize == 0)
402 fifosize = 1;
403
404 return fifosize;
405}
406
407static void apbuart_flush_fifo(struct uart_port *port)
408{
409 int i;
410
411 for (i = 0; i < port->fifosize; i++)
412 UART_GET_CHAR(port);
413}
414
415
416/* ======================================================================== */
417/* Console driver, if enabled */
418/* ======================================================================== */
419
420#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
421
422static void apbuart_console_putchar(struct uart_port *port, int ch)
423{
424 unsigned int status;
425 do {
426 status = UART_GET_STATUS(port);
427 } while (!UART_TX_READY(status));
428 UART_PUT_CHAR(port, ch);
429}
430
431static void
432apbuart_console_write(struct console *co, const char *s, unsigned int count)
433{
434 struct uart_port *port = &grlib_apbuart_ports[co->index];
435 unsigned int status, old_cr, new_cr;
436
437 /* First save the CR then disable the interrupts */
438 old_cr = UART_GET_CTRL(port);
439 new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
440 UART_PUT_CTRL(port, new_cr);
441
442 uart_console_write(port, s, count, apbuart_console_putchar);
443
444 /*
445 * Finally, wait for transmitter to become empty
446 * and restore the TCR
447 */
448 do {
449 status = UART_GET_STATUS(port);
450 } while (!UART_TX_READY(status));
451 UART_PUT_CTRL(port, old_cr);
452}
453
454static void __init
455apbuart_console_get_options(struct uart_port *port, int *baud,
456 int *parity, int *bits)
457{
458 if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
459
460 unsigned int quot, status;
461 status = UART_GET_STATUS(port);
462
463 *parity = 'n';
464 if (status & UART_CTRL_PE) {
465 if ((status & UART_CTRL_PS) == 0)
466 *parity = 'e';
467 else
468 *parity = 'o';
469 }
470
471 *bits = 8;
472 quot = UART_GET_SCAL(port) / 8;
473 *baud = port->uartclk / (16 * (quot + 1));
474 }
475}
476
477static int __init apbuart_console_setup(struct console *co, char *options)
478{
479 struct uart_port *port;
480 int baud = 38400;
481 int bits = 8;
482 int parity = 'n';
483 int flow = 'n';
484
485 pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
486 co, co->index, options);
487
488 /*
489 * Check whether an invalid uart number has been specified, and
490 * if so, search for the first available port that does have
491 * console support.
492 */
493 if (co->index >= grlib_apbuart_port_nr)
494 co->index = 0;
495
496 port = &grlib_apbuart_ports[co->index];
497
498 spin_lock_init(&port->lock);
499
500 if (options)
501 uart_parse_options(options, &baud, &parity, &bits, &flow);
502 else
503 apbuart_console_get_options(port, &baud, &parity, &bits);
504
505 return uart_set_options(port, co, baud, parity, bits, flow);
506}
507
508static struct uart_driver grlib_apbuart_driver;
509
510static struct console grlib_apbuart_console = {
511 .name = "ttyS",
512 .write = apbuart_console_write,
513 .device = uart_console_device,
514 .setup = apbuart_console_setup,
515 .flags = CON_PRINTBUFFER,
516 .index = -1,
517 .data = &grlib_apbuart_driver,
518};
519
520
521static int grlib_apbuart_configure(void);
522
523static int __init apbuart_console_init(void)
524{
525 if (grlib_apbuart_configure())
526 return -ENODEV;
527 register_console(&grlib_apbuart_console);
528 return 0;
529}
530
531console_initcall(apbuart_console_init);
532
533#define APBUART_CONSOLE (&grlib_apbuart_console)
534#else
535#define APBUART_CONSOLE NULL
536#endif
537
538static struct uart_driver grlib_apbuart_driver = {
539 .owner = THIS_MODULE,
540 .driver_name = "serial",
541 .dev_name = "ttyS",
542 .major = SERIAL_APBUART_MAJOR,
543 .minor = SERIAL_APBUART_MINOR,
544 .nr = UART_NR,
545 .cons = APBUART_CONSOLE,
546};
547
548
549/* ======================================================================== */
550/* OF Platform Driver */
551/* ======================================================================== */
552
553static int apbuart_probe(struct platform_device *op)
554{
555 int i;
556 struct uart_port *port = NULL;
557
558 for (i = 0; i < grlib_apbuart_port_nr; i++) {
559 if (op->dev.of_node == grlib_apbuart_nodes[i])
560 break;
561 }
562
563 port = &grlib_apbuart_ports[i];
564 port->dev = &op->dev;
565 port->irq = op->archdata.irqs[0];
566
567 uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
568
569 apbuart_flush_fifo((struct uart_port *) port);
570
571 printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
572 (unsigned long long) port->mapbase, port->irq);
573 return 0;
574}
575
576static const struct of_device_id apbuart_match[] = {
577 {
578 .name = "GAISLER_APBUART",
579 },
580 {
581 .name = "01_00c",
582 },
583 {},
584};
585MODULE_DEVICE_TABLE(of, apbuart_match);
586
587static struct platform_driver grlib_apbuart_of_driver = {
588 .probe = apbuart_probe,
589 .driver = {
590 .name = "grlib-apbuart",
591 .of_match_table = apbuart_match,
592 },
593};
594
595
596static int __init grlib_apbuart_configure(void)
597{
598 struct device_node *np;
599 int line = 0;
600
601 for_each_matching_node(np, apbuart_match) {
602 const int *ampopts;
603 const u32 *freq_hz;
604 const struct amba_prom_registers *regs;
605 struct uart_port *port;
606 unsigned long addr;
607
608 ampopts = of_get_property(np, "ampopts", NULL);
609 if (ampopts && (*ampopts == 0))
610 continue; /* Ignore if used by another OS instance */
611 regs = of_get_property(np, "reg", NULL);
612 /* Frequency of APB Bus is frequency of UART */
613 freq_hz = of_get_property(np, "freq", NULL);
614
615 if (!regs || !freq_hz || (*freq_hz == 0))
616 continue;
617
618 grlib_apbuart_nodes[line] = np;
619
620 addr = regs->phys_addr;
621
622 port = &grlib_apbuart_ports[line];
623
624 port->mapbase = addr;
625 port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
626 port->irq = 0;
627 port->iotype = UPIO_MEM;
628 port->ops = &grlib_apbuart_ops;
629 port->flags = UPF_BOOT_AUTOCONF;
630 port->line = line;
631 port->uartclk = *freq_hz;
632 port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
633 line++;
634
635 /* We support maximum UART_NR uarts ... */
636 if (line == UART_NR)
637 break;
638 }
639
640 grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
641 return line ? 0 : -ENODEV;
642}
643
644static int __init grlib_apbuart_init(void)
645{
646 int ret;
647
648 /* Find all APBUARTS in device the tree and initialize their ports */
649 ret = grlib_apbuart_configure();
650 if (ret)
651 return ret;
652
653 printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
654
655 ret = uart_register_driver(&grlib_apbuart_driver);
656
657 if (ret) {
658 printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
659 __FILE__, ret);
660 return ret;
661 }
662
663 ret = platform_driver_register(&grlib_apbuart_of_driver);
664 if (ret) {
665 printk(KERN_ERR
666 "%s: platform_driver_register failed (%i)\n",
667 __FILE__, ret);
668 uart_unregister_driver(&grlib_apbuart_driver);
669 return ret;
670 }
671
672 return ret;
673}
674
675static void __exit grlib_apbuart_exit(void)
676{
677 int i;
678
679 for (i = 0; i < grlib_apbuart_port_nr; i++)
680 uart_remove_one_port(&grlib_apbuart_driver,
681 &grlib_apbuart_ports[i]);
682
683 uart_unregister_driver(&grlib_apbuart_driver);
684 platform_driver_unregister(&grlib_apbuart_of_driver);
685}
686
687module_init(grlib_apbuart_init);
688module_exit(grlib_apbuart_exit);
689
690MODULE_AUTHOR("Aeroflex Gaisler AB");
691MODULE_DESCRIPTION("GRLIB APBUART serial driver");
692MODULE_VERSION("2.1");
693MODULE_LICENSE("GPL");