?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[cris-mirror.git] / drivers / tty / serial / mvebu-uart.c
blob0ff27818bb87da5ec04f03a041ceb4254c5a9ca0
1 /*
2 * ***************************************************************************
3 * Copyright (C) 2015 Marvell International Ltd.
4 * ***************************************************************************
5 * This program is free software: you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the Free
7 * Software Foundation, either version 2 of the License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 * ***************************************************************************
17 */
18
19 #include <linux/clk.h>
20 #include <linux/console.h>
21 #include <linux/delay.h>
22 #include <linux/device.h>
23 #include <linux/init.h>
24 #include <linux/io.h>
25 #include <linux/iopoll.h>
26 #include <linux/module.h>
27 #include <linux/of.h>
28 #include <linux/of_address.h>
29 #include <linux/of_device.h>
30 #include <linux/of_irq.h>
31 #include <linux/of_platform.h>
32 #include <linux/platform_device.h>
33 #include <linux/serial.h>
34 #include <linux/serial_core.h>
35 #include <linux/slab.h>
36 #include <linux/tty.h>
37 #include <linux/tty_flip.h>
38
39 /* Register Map */
40 #define UART_RBR 0x00
41 #define RBR_BRK_DET BIT(15)
42 #define RBR_FRM_ERR_DET BIT(14)
43 #define RBR_PAR_ERR_DET BIT(13)
44 #define RBR_OVR_ERR_DET BIT(12)
45
46 #define UART_TSH 0x04
47
48 #define UART_CTRL 0x08
49 #define CTRL_SOFT_RST BIT(31)
50 #define CTRL_TXFIFO_RST BIT(15)
51 #define CTRL_RXFIFO_RST BIT(14)
52 #define CTRL_ST_MIRR_EN BIT(13)
53 #define CTRL_LPBK_EN BIT(12)
54 #define CTRL_SND_BRK_SEQ BIT(11)
55 #define CTRL_PAR_EN BIT(10)
56 #define CTRL_TWO_STOP BIT(9)
57 #define CTRL_TX_HFL_INT BIT(8)
58 #define CTRL_RX_HFL_INT BIT(7)
59 #define CTRL_TX_EMP_INT BIT(6)
60 #define CTRL_TX_RDY_INT BIT(5)
61 #define CTRL_RX_RDY_INT BIT(4)
62 #define CTRL_BRK_DET_INT BIT(3)
63 #define CTRL_FRM_ERR_INT BIT(2)
64 #define CTRL_PAR_ERR_INT BIT(1)
65 #define CTRL_OVR_ERR_INT BIT(0)
66 #define CTRL_RX_INT (CTRL_RX_RDY_INT | CTRL_BRK_DET_INT |\
67 CTRL_FRM_ERR_INT | CTRL_PAR_ERR_INT | CTRL_OVR_ERR_INT)
68
69 #define UART_STAT 0x0c
70 #define STAT_TX_FIFO_EMP BIT(13)
71 #define STAT_RX_FIFO_EMP BIT(12)
72 #define STAT_TX_FIFO_FUL BIT(11)
73 #define STAT_TX_FIFO_HFL BIT(10)
74 #define STAT_RX_TOGL BIT(9)
75 #define STAT_RX_FIFO_FUL BIT(8)
76 #define STAT_RX_FIFO_HFL BIT(7)
77 #define STAT_TX_EMP BIT(6)
78 #define STAT_TX_RDY BIT(5)
79 #define STAT_RX_RDY BIT(4)
80 #define STAT_BRK_DET BIT(3)
81 #define STAT_FRM_ERR BIT(2)
82 #define STAT_PAR_ERR BIT(1)
83 #define STAT_OVR_ERR BIT(0)
84 #define STAT_BRK_ERR (STAT_BRK_DET | STAT_FRM_ERR | STAT_FRM_ERR\
85 | STAT_PAR_ERR | STAT_OVR_ERR)
86
87 #define UART_BRDV 0x10
88
89 #define MVEBU_NR_UARTS 1
90
91 #define MVEBU_UART_TYPE "mvebu-uart"
92
93 static struct uart_port mvebu_uart_ports[MVEBU_NR_UARTS];
94
95 struct mvebu_uart_data {
96 struct uart_port *port;
97 struct clk *clk;
98 };
99
100 /* Core UART Driver Operations */
101 static unsigned int mvebu_uart_tx_empty(struct uart_port *port)
102 {
103 unsigned long flags;
104 unsigned int st;
105
106 spin_lock_irqsave(&port->lock, flags);
107 st = readl(port->membase + UART_STAT);
108 spin_unlock_irqrestore(&port->lock, flags);
109
110 return (st & STAT_TX_FIFO_EMP) ? TIOCSER_TEMT : 0;
111 }
112
113 static unsigned int mvebu_uart_get_mctrl(struct uart_port *port)
114 {
115 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
116 }
117
118 static void mvebu_uart_set_mctrl(struct uart_port *port,
119 unsigned int mctrl)
120 {
121 /*
122 * Even if we do not support configuring the modem control lines, this
123 * function must be proided to the serial core
124 */
125 }
126
127 static void mvebu_uart_stop_tx(struct uart_port *port)
128 {
129 unsigned int ctl = readl(port->membase + UART_CTRL);
130
131 ctl &= ~CTRL_TX_RDY_INT;
132 writel(ctl, port->membase + UART_CTRL);
133 }
134
135 static void mvebu_uart_start_tx(struct uart_port *port)
136 {
137 unsigned int ctl = readl(port->membase + UART_CTRL);
138
139 ctl |= CTRL_TX_RDY_INT;
140 writel(ctl, port->membase + UART_CTRL);
141 }
142
143 static void mvebu_uart_stop_rx(struct uart_port *port)
144 {
145 unsigned int ctl = readl(port->membase + UART_CTRL);
146
147 ctl &= ~CTRL_RX_INT;
148 writel(ctl, port->membase + UART_CTRL);
149 }
150
151 static void mvebu_uart_break_ctl(struct uart_port *port, int brk)
152 {
153 unsigned int ctl;
154 unsigned long flags;
155
156 spin_lock_irqsave(&port->lock, flags);
157 ctl = readl(port->membase + UART_CTRL);
158 if (brk == -1)
159 ctl |= CTRL_SND_BRK_SEQ;
160 else
161 ctl &= ~CTRL_SND_BRK_SEQ;
162 writel(ctl, port->membase + UART_CTRL);
163 spin_unlock_irqrestore(&port->lock, flags);
164 }
165
166 static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
167 {
168 struct tty_port *tport = &port->state->port;
169 unsigned char ch = 0;
170 char flag = 0;
171
172 do {
173 if (status & STAT_RX_RDY) {
174 ch = readl(port->membase + UART_RBR);
175 ch &= 0xff;
176 flag = TTY_NORMAL;
177 port->icount.rx++;
178
179 if (status & STAT_PAR_ERR)
180 port->icount.parity++;
181 }
182
183 if (status & STAT_BRK_DET) {
184 port->icount.brk++;
185 status &= ~(STAT_FRM_ERR | STAT_PAR_ERR);
186 if (uart_handle_break(port))
187 goto ignore_char;
188 }
189
190 if (status & STAT_OVR_ERR)
191 port->icount.overrun++;
192
193 if (status & STAT_FRM_ERR)
194 port->icount.frame++;
195
196 if (uart_handle_sysrq_char(port, ch))
197 goto ignore_char;
198
199 if (status & port->ignore_status_mask & STAT_PAR_ERR)
200 status &= ~STAT_RX_RDY;
201
202 status &= port->read_status_mask;
203
204 if (status & STAT_PAR_ERR)
205 flag = TTY_PARITY;
206
207 status &= ~port->ignore_status_mask;
208
209 if (status & STAT_RX_RDY)
210 tty_insert_flip_char(tport, ch, flag);
211
212 if (status & STAT_BRK_DET)
213 tty_insert_flip_char(tport, 0, TTY_BREAK);
214
215 if (status & STAT_FRM_ERR)
216 tty_insert_flip_char(tport, 0, TTY_FRAME);
217
218 if (status & STAT_OVR_ERR)
219 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
220
221 ignore_char:
222 status = readl(port->membase + UART_STAT);
223 } while (status & (STAT_RX_RDY | STAT_BRK_DET));
224
225 tty_flip_buffer_push(tport);
226 }
227
228 static void mvebu_uart_tx_chars(struct uart_port *port, unsigned int status)
229 {
230 struct circ_buf *xmit = &port->state->xmit;
231 unsigned int count;
232 unsigned int st;
233
234 if (port->x_char) {
235 writel(port->x_char, port->membase + UART_TSH);
236 port->icount.tx++;
237 port->x_char = 0;
238 return;
239 }
240
241 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
242 mvebu_uart_stop_tx(port);
243 return;
244 }
245
246 for (count = 0; count < port->fifosize; count++) {
247 writel(xmit->buf[xmit->tail], port->membase + UART_TSH);
248 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
249 port->icount.tx++;
250
251 if (uart_circ_empty(xmit))
252 break;
253
254 st = readl(port->membase + UART_STAT);
255 if (st & STAT_TX_FIFO_FUL)
256 break;
257 }
258
259 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
260 uart_write_wakeup(port);
261
262 if (uart_circ_empty(xmit))
263 mvebu_uart_stop_tx(port);
264 }
265
266 static irqreturn_t mvebu_uart_isr(int irq, void *dev_id)
267 {
268 struct uart_port *port = (struct uart_port *)dev_id;
269 unsigned int st = readl(port->membase + UART_STAT);
270
271 if (st & (STAT_RX_RDY | STAT_OVR_ERR | STAT_FRM_ERR | STAT_BRK_DET))
272 mvebu_uart_rx_chars(port, st);
273
274 if (st & STAT_TX_RDY)
275 mvebu_uart_tx_chars(port, st);
276
277 return IRQ_HANDLED;
278 }
279
280 static int mvebu_uart_startup(struct uart_port *port)
281 {
282 int ret;
283
284 writel(CTRL_TXFIFO_RST | CTRL_RXFIFO_RST,
285 port->membase + UART_CTRL);
286 udelay(1);
287 writel(CTRL_RX_INT, port->membase + UART_CTRL);
288
289 ret = request_irq(port->irq, mvebu_uart_isr, port->irqflags, "serial",
290 port);
291 if (ret) {
292 dev_err(port->dev, "failed to request irq\n");
293 return ret;
294 }
295
296 return 0;
297 }
298
299 static void mvebu_uart_shutdown(struct uart_port *port)
300 {
301 writel(0, port->membase + UART_CTRL);
302 }
303
304 static void mvebu_uart_set_termios(struct uart_port *port,
305 struct ktermios *termios,
306 struct ktermios *old)
307 {
308 unsigned long flags;
309 unsigned int baud;
310
311 spin_lock_irqsave(&port->lock, flags);
312
313 port->read_status_mask = STAT_RX_RDY | STAT_OVR_ERR |
314 STAT_TX_RDY | STAT_TX_FIFO_FUL;
315
316 if (termios->c_iflag & INPCK)
317 port->read_status_mask |= STAT_FRM_ERR | STAT_PAR_ERR;
318
319 port->ignore_status_mask = 0;
320 if (termios->c_iflag & IGNPAR)
321 port->ignore_status_mask |=
322 STAT_FRM_ERR | STAT_PAR_ERR | STAT_OVR_ERR;
323
324 if ((termios->c_cflag & CREAD) == 0)
325 port->ignore_status_mask |= STAT_RX_RDY | STAT_BRK_ERR;
326
327 if (old)
328 tty_termios_copy_hw(termios, old);
329
330 baud = uart_get_baud_rate(port, termios, old, 0, 460800);
331 uart_update_timeout(port, termios->c_cflag, baud);
332
333 spin_unlock_irqrestore(&port->lock, flags);
334 }
335
336 static const char *mvebu_uart_type(struct uart_port *port)
337 {
338 return MVEBU_UART_TYPE;
339 }
340
341 static void mvebu_uart_release_port(struct uart_port *port)
342 {
343 /* Nothing to do here */
344 }
345
346 static int mvebu_uart_request_port(struct uart_port *port)
347 {
348 return 0;
349 }
350
351 #ifdef CONFIG_CONSOLE_POLL
352 static int mvebu_uart_get_poll_char(struct uart_port *port)
353 {
354 unsigned int st = readl(port->membase + UART_STAT);
355
356 if (!(st & STAT_RX_RDY))
357 return NO_POLL_CHAR;
358
359 return readl(port->membase + UART_RBR);
360 }
361
362 static void mvebu_uart_put_poll_char(struct uart_port *port, unsigned char c)
363 {
364 unsigned int st;
365
366 for (;;) {
367 st = readl(port->membase + UART_STAT);
368
369 if (!(st & STAT_TX_FIFO_FUL))
370 break;
371
372 udelay(1);
373 }
374
375 writel(c, port->membase + UART_TSH);
376 }
377 #endif
378
379 static const struct uart_ops mvebu_uart_ops = {
380 .tx_empty = mvebu_uart_tx_empty,
381 .set_mctrl = mvebu_uart_set_mctrl,
382 .get_mctrl = mvebu_uart_get_mctrl,
383 .stop_tx = mvebu_uart_stop_tx,
384 .start_tx = mvebu_uart_start_tx,
385 .stop_rx = mvebu_uart_stop_rx,
386 .break_ctl = mvebu_uart_break_ctl,
387 .startup = mvebu_uart_startup,
388 .shutdown = mvebu_uart_shutdown,
389 .set_termios = mvebu_uart_set_termios,
390 .type = mvebu_uart_type,
391 .release_port = mvebu_uart_release_port,
392 .request_port = mvebu_uart_request_port,
393 #ifdef CONFIG_CONSOLE_POLL
394 .poll_get_char = mvebu_uart_get_poll_char,
395 .poll_put_char = mvebu_uart_put_poll_char,
396 #endif
397 };
398
399 /* Console Driver Operations */
400
401 #ifdef CONFIG_SERIAL_MVEBU_CONSOLE
402 /* Early Console */
403 static void mvebu_uart_putc(struct uart_port *port, int c)
404 {
405 unsigned int st;
406
407 for (;;) {
408 st = readl(port->membase + UART_STAT);
409 if (!(st & STAT_TX_FIFO_FUL))
410 break;
411 }
412
413 writel(c, port->membase + UART_TSH);
414
415 for (;;) {
416 st = readl(port->membase + UART_STAT);
417 if (st & STAT_TX_FIFO_EMP)
418 break;
419 }
420 }
421
422 static void mvebu_uart_putc_early_write(struct console *con,
423 const char *s,
424 unsigned n)
425 {
426 struct earlycon_device *dev = con->data;
427
428 uart_console_write(&dev->port, s, n, mvebu_uart_putc);
429 }
430
431 static int __init
432 mvebu_uart_early_console_setup(struct earlycon_device *device,
433 const char *opt)
434 {
435 if (!device->port.membase)
436 return -ENODEV;
437
438 device->con->write = mvebu_uart_putc_early_write;
439
440 return 0;
441 }
442
443 EARLYCON_DECLARE(ar3700_uart, mvebu_uart_early_console_setup);
444 OF_EARLYCON_DECLARE(ar3700_uart, "marvell,armada-3700-uart",
445 mvebu_uart_early_console_setup);
446
447 static void wait_for_xmitr(struct uart_port *port)
448 {
449 u32 val;
450
451 readl_poll_timeout_atomic(port->membase + UART_STAT, val,
452 (val & STAT_TX_EMP), 1, 10000);
453 }
454
455 static void mvebu_uart_console_putchar(struct uart_port *port, int ch)
456 {
457 wait_for_xmitr(port);
458 writel(ch, port->membase + UART_TSH);
459 }
460
461 static void mvebu_uart_console_write(struct console *co, const char *s,
462 unsigned int count)
463 {
464 struct uart_port *port = &mvebu_uart_ports[co->index];
465 unsigned long flags;
466 unsigned int ier;
467 int locked = 1;
468
469 if (oops_in_progress)
470 locked = spin_trylock_irqsave(&port->lock, flags);
471 else
472 spin_lock_irqsave(&port->lock, flags);
473
474 ier = readl(port->membase + UART_CTRL) &
475 (CTRL_RX_INT | CTRL_TX_RDY_INT);
476 writel(0, port->membase + UART_CTRL);
477
478 uart_console_write(port, s, count, mvebu_uart_console_putchar);
479
480 wait_for_xmitr(port);
481
482 if (ier)
483 writel(ier, port->membase + UART_CTRL);
484
485 if (locked)
486 spin_unlock_irqrestore(&port->lock, flags);
487 }
488
489 static int mvebu_uart_console_setup(struct console *co, char *options)
490 {
491 struct uart_port *port;
492 int baud = 9600;
493 int bits = 8;
494 int parity = 'n';
495 int flow = 'n';
496
497 if (co->index < 0 || co->index >= MVEBU_NR_UARTS)
498 return -EINVAL;
499
500 port = &mvebu_uart_ports[co->index];
501
502 if (!port->mapbase || !port->membase) {
503 pr_debug("console on ttyMV%i not present\n", co->index);
504 return -ENODEV;
505 }
506
507 if (options)
508 uart_parse_options(options, &baud, &parity, &bits, &flow);
509
510 return uart_set_options(port, co, baud, parity, bits, flow);
511 }
512
513 static struct uart_driver mvebu_uart_driver;
514
515 static struct console mvebu_uart_console = {
516 .name = "ttyMV",
517 .write = mvebu_uart_console_write,
518 .device = uart_console_device,
519 .setup = mvebu_uart_console_setup,
520 .flags = CON_PRINTBUFFER,
521 .index = -1,
522 .data = &mvebu_uart_driver,
523 };
524
525 static int __init mvebu_uart_console_init(void)
526 {
527 register_console(&mvebu_uart_console);
528 return 0;
529 }
530
531 console_initcall(mvebu_uart_console_init);
532
533
534 #endif /* CONFIG_SERIAL_MVEBU_CONSOLE */
535
536 static struct uart_driver mvebu_uart_driver = {
537 .owner = THIS_MODULE,
538 .driver_name = "mvebu_serial",
539 .dev_name = "ttyMV",
540 .nr = MVEBU_NR_UARTS,
541 #ifdef CONFIG_SERIAL_MVEBU_CONSOLE
542 .cons = &mvebu_uart_console,
543 #endif
544 };
545
546 static int mvebu_uart_probe(struct platform_device *pdev)
547 {
548 struct resource *reg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
549 struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
550 struct uart_port *port;
551 struct mvebu_uart_data *data;
552 int ret;
553
554 if (!reg || !irq) {
555 dev_err(&pdev->dev, "no registers/irq defined\n");
556 return -EINVAL;
557 }
558
559 port = &mvebu_uart_ports[0];
560
561 spin_lock_init(&port->lock);
562
563 port->dev = &pdev->dev;
564 port->type = PORT_MVEBU;
565 port->ops = &mvebu_uart_ops;
566 port->regshift = 0;
567
568 port->fifosize = 32;
569 port->iotype = UPIO_MEM32;
570 port->flags = UPF_FIXED_PORT;
571 port->line = 0; /* single port: force line number to 0 */
572
573 port->irq = irq->start;
574 port->irqflags = 0;
575 port->mapbase = reg->start;
576
577 port->membase = devm_ioremap_resource(&pdev->dev, reg);
578 if (IS_ERR(port->membase))
579 return -PTR_ERR(port->membase);
580
581 data = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_uart_data),
582 GFP_KERNEL);
583 if (!data)
584 return -ENOMEM;
585
586 data->port = port;
587
588 port->private_data = data;
589 platform_set_drvdata(pdev, data);
590
591 ret = uart_add_one_port(&mvebu_uart_driver, port);
592 if (ret)
593 return ret;
594 return 0;
595 }
596
597 static int mvebu_uart_remove(struct platform_device *pdev)
598 {
599 struct mvebu_uart_data *data = platform_get_drvdata(pdev);
600
601 uart_remove_one_port(&mvebu_uart_driver, data->port);
602 data->port->private_data = NULL;
603 data->port->mapbase = 0;
604 return 0;
605 }
606
607 /* Match table for of_platform binding */
608 static const struct of_device_id mvebu_uart_of_match[] = {
609 { .compatible = "marvell,armada-3700-uart", },
610 {}
611 };
612 MODULE_DEVICE_TABLE(of, mvebu_uart_of_match);
613
614 static struct platform_driver mvebu_uart_platform_driver = {
615 .probe = mvebu_uart_probe,
616 .remove = mvebu_uart_remove,
617 .driver = {
618 .owner = THIS_MODULE,
619 .name = "mvebu-uart",
620 .of_match_table = of_match_ptr(mvebu_uart_of_match),
621 },
622 };
623
624 static int __init mvebu_uart_init(void)
625 {
626 int ret;
627
628 ret = uart_register_driver(&mvebu_uart_driver);
629 if (ret)
630 return ret;
631
632 ret = platform_driver_register(&mvebu_uart_platform_driver);
633 if (ret)
634 uart_unregister_driver(&mvebu_uart_driver);
635
636 return ret;
637 }
638
639 static void __exit mvebu_uart_exit(void)
640 {
641 platform_driver_unregister(&mvebu_uart_platform_driver);
642 uart_unregister_driver(&mvebu_uart_driver);
643 }
644
645 arch_initcall(mvebu_uart_init);
646 module_exit(mvebu_uart_exit);
647
648 MODULE_AUTHOR("Wilson Ding <dingwei@marvell.com>");
649 MODULE_DESCRIPTION("Marvell Armada-3700 Serial Driver");
650 MODULE_LICENSE("GPL");
CRIS linux kernel tree