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powerpc/kprobes: Remove kretprobe_trampoline_holder.
[linux/fpc-iii.git] / drivers / tty / serial / mvebu-uart.c
blobce362bd51de78d65177c889541e80d33aae1779d
1 /*
2 * ***************************************************************************
3 * Marvell Armada-3700 Serial Driver
4 * Author: Wilson Ding <dingwei@marvell.com>
5 * Copyright (C) 2015 Marvell International Ltd.
6 * ***************************************************************************
7 * This program is free software: you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the Free
9 * Software Foundation, either version 2 of the License, or any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 * ***************************************************************************
19 */
20
21 #include <linux/clk.h>
22 #include <linux/console.h>
23 #include <linux/delay.h>
24 #include <linux/device.h>
25 #include <linux/init.h>
26 #include <linux/io.h>
27 #include <linux/iopoll.h>
28 #include <linux/of.h>
29 #include <linux/of_address.h>
30 #include <linux/of_device.h>
31 #include <linux/of_irq.h>
32 #include <linux/of_platform.h>
33 #include <linux/platform_device.h>
34 #include <linux/serial.h>
35 #include <linux/serial_core.h>
36 #include <linux/slab.h>
37 #include <linux/tty.h>
38 #include <linux/tty_flip.h>
39
40 /* Register Map */
41 #define UART_RBR 0x00
42 #define RBR_BRK_DET BIT(15)
43 #define RBR_FRM_ERR_DET BIT(14)
44 #define RBR_PAR_ERR_DET BIT(13)
45 #define RBR_OVR_ERR_DET BIT(12)
46
47 #define UART_TSH 0x04
48
49 #define UART_CTRL 0x08
50 #define CTRL_SOFT_RST BIT(31)
51 #define CTRL_TXFIFO_RST BIT(15)
52 #define CTRL_RXFIFO_RST BIT(14)
53 #define CTRL_ST_MIRR_EN BIT(13)
54 #define CTRL_LPBK_EN BIT(12)
55 #define CTRL_SND_BRK_SEQ BIT(11)
56 #define CTRL_PAR_EN BIT(10)
57 #define CTRL_TWO_STOP BIT(9)
58 #define CTRL_TX_HFL_INT BIT(8)
59 #define CTRL_RX_HFL_INT BIT(7)
60 #define CTRL_TX_EMP_INT BIT(6)
61 #define CTRL_TX_RDY_INT BIT(5)
62 #define CTRL_RX_RDY_INT BIT(4)
63 #define CTRL_BRK_DET_INT BIT(3)
64 #define CTRL_FRM_ERR_INT BIT(2)
65 #define CTRL_PAR_ERR_INT BIT(1)
66 #define CTRL_OVR_ERR_INT BIT(0)
67 #define CTRL_RX_INT (CTRL_RX_RDY_INT | CTRL_BRK_DET_INT |\
68 CTRL_FRM_ERR_INT | CTRL_PAR_ERR_INT | CTRL_OVR_ERR_INT)
69
70 #define UART_STAT 0x0c
71 #define STAT_TX_FIFO_EMP BIT(13)
72 #define STAT_RX_FIFO_EMP BIT(12)
73 #define STAT_TX_FIFO_FUL BIT(11)
74 #define STAT_TX_FIFO_HFL BIT(10)
75 #define STAT_RX_TOGL BIT(9)
76 #define STAT_RX_FIFO_FUL BIT(8)
77 #define STAT_RX_FIFO_HFL BIT(7)
78 #define STAT_TX_EMP BIT(6)
79 #define STAT_TX_RDY BIT(5)
80 #define STAT_RX_RDY BIT(4)
81 #define STAT_BRK_DET BIT(3)
82 #define STAT_FRM_ERR BIT(2)
83 #define STAT_PAR_ERR BIT(1)
84 #define STAT_OVR_ERR BIT(0)
85 #define STAT_BRK_ERR (STAT_BRK_DET | STAT_FRM_ERR | STAT_FRM_ERR\
86 | STAT_PAR_ERR | STAT_OVR_ERR)
87
88 #define UART_BRDV 0x10
89
90 #define MVEBU_NR_UARTS 1
91
92 #define MVEBU_UART_TYPE "mvebu-uart"
93
94 static struct uart_port mvebu_uart_ports[MVEBU_NR_UARTS];
95
96 struct mvebu_uart_data {
97 struct uart_port *port;
98 struct clk *clk;
99 };
100
101 /* Core UART Driver Operations */
102 static unsigned int mvebu_uart_tx_empty(struct uart_port *port)
103 {
104 unsigned long flags;
105 unsigned int st;
106
107 spin_lock_irqsave(&port->lock, flags);
108 st = readl(port->membase + UART_STAT);
109 spin_unlock_irqrestore(&port->lock, flags);
110
111 return (st & STAT_TX_FIFO_EMP) ? TIOCSER_TEMT : 0;
112 }
113
114 static unsigned int mvebu_uart_get_mctrl(struct uart_port *port)
115 {
116 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
117 }
118
119 static void mvebu_uart_set_mctrl(struct uart_port *port,
120 unsigned int mctrl)
121 {
122 /*
123 * Even if we do not support configuring the modem control lines, this
124 * function must be proided to the serial core
125 */
126 }
127
128 static void mvebu_uart_stop_tx(struct uart_port *port)
129 {
130 unsigned int ctl = readl(port->membase + UART_CTRL);
131
132 ctl &= ~CTRL_TX_RDY_INT;
133 writel(ctl, port->membase + UART_CTRL);
134 }
135
136 static void mvebu_uart_start_tx(struct uart_port *port)
137 {
138 unsigned int ctl = readl(port->membase + UART_CTRL);
139
140 ctl |= CTRL_TX_RDY_INT;
141 writel(ctl, port->membase + UART_CTRL);
142 }
143
144 static void mvebu_uart_stop_rx(struct uart_port *port)
145 {
146 unsigned int ctl = readl(port->membase + UART_CTRL);
147
148 ctl &= ~CTRL_RX_INT;
149 writel(ctl, port->membase + UART_CTRL);
150 }
151
152 static void mvebu_uart_break_ctl(struct uart_port *port, int brk)
153 {
154 unsigned int ctl;
155 unsigned long flags;
156
157 spin_lock_irqsave(&port->lock, flags);
158 ctl = readl(port->membase + UART_CTRL);
159 if (brk == -1)
160 ctl |= CTRL_SND_BRK_SEQ;
161 else
162 ctl &= ~CTRL_SND_BRK_SEQ;
163 writel(ctl, port->membase + UART_CTRL);
164 spin_unlock_irqrestore(&port->lock, flags);
165 }
166
167 static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
168 {
169 struct tty_port *tport = &port->state->port;
170 unsigned char ch = 0;
171 char flag = 0;
172
173 do {
174 if (status & STAT_RX_RDY) {
175 ch = readl(port->membase + UART_RBR);
176 ch &= 0xff;
177 flag = TTY_NORMAL;
178 port->icount.rx++;
179
180 if (status & STAT_PAR_ERR)
181 port->icount.parity++;
182 }
183
184 if (status & STAT_BRK_DET) {
185 port->icount.brk++;
186 status &= ~(STAT_FRM_ERR | STAT_PAR_ERR);
187 if (uart_handle_break(port))
188 goto ignore_char;
189 }
190
191 if (status & STAT_OVR_ERR)
192 port->icount.overrun++;
193
194 if (status & STAT_FRM_ERR)
195 port->icount.frame++;
196
197 if (uart_handle_sysrq_char(port, ch))
198 goto ignore_char;
199
200 if (status & port->ignore_status_mask & STAT_PAR_ERR)
201 status &= ~STAT_RX_RDY;
202
203 status &= port->read_status_mask;
204
205 if (status & STAT_PAR_ERR)
206 flag = TTY_PARITY;
207
208 status &= ~port->ignore_status_mask;
209
210 if (status & STAT_RX_RDY)
211 tty_insert_flip_char(tport, ch, flag);
212
213 if (status & STAT_BRK_DET)
214 tty_insert_flip_char(tport, 0, TTY_BREAK);
215
216 if (status & STAT_FRM_ERR)
217 tty_insert_flip_char(tport, 0, TTY_FRAME);
218
219 if (status & STAT_OVR_ERR)
220 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
221
222 ignore_char:
223 status = readl(port->membase + UART_STAT);
224 } while (status & (STAT_RX_RDY | STAT_BRK_DET));
225
226 tty_flip_buffer_push(tport);
227 }
228
229 static void mvebu_uart_tx_chars(struct uart_port *port, unsigned int status)
230 {
231 struct circ_buf *xmit = &port->state->xmit;
232 unsigned int count;
233 unsigned int st;
234
235 if (port->x_char) {
236 writel(port->x_char, port->membase + UART_TSH);
237 port->icount.tx++;
238 port->x_char = 0;
239 return;
240 }
241
242 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
243 mvebu_uart_stop_tx(port);
244 return;
245 }
246
247 for (count = 0; count < port->fifosize; count++) {
248 writel(xmit->buf[xmit->tail], port->membase + UART_TSH);
249 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
250 port->icount.tx++;
251
252 if (uart_circ_empty(xmit))
253 break;
254
255 st = readl(port->membase + UART_STAT);
256 if (st & STAT_TX_FIFO_FUL)
257 break;
258 }
259
260 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
261 uart_write_wakeup(port);
262
263 if (uart_circ_empty(xmit))
264 mvebu_uart_stop_tx(port);
265 }
266
267 static irqreturn_t mvebu_uart_isr(int irq, void *dev_id)
268 {
269 struct uart_port *port = (struct uart_port *)dev_id;
270 unsigned int st = readl(port->membase + UART_STAT);
271
272 if (st & (STAT_RX_RDY | STAT_OVR_ERR | STAT_FRM_ERR | STAT_BRK_DET))
273 mvebu_uart_rx_chars(port, st);
274
275 if (st & STAT_TX_RDY)
276 mvebu_uart_tx_chars(port, st);
277
278 return IRQ_HANDLED;
279 }
280
281 static int mvebu_uart_startup(struct uart_port *port)
282 {
283 int ret;
284
285 writel(CTRL_TXFIFO_RST | CTRL_RXFIFO_RST,
286 port->membase + UART_CTRL);
287 udelay(1);
288 writel(CTRL_RX_INT, port->membase + UART_CTRL);
289
290 ret = request_irq(port->irq, mvebu_uart_isr, port->irqflags, "serial",
291 port);
292 if (ret) {
293 dev_err(port->dev, "failed to request irq\n");
294 return ret;
295 }
296
297 return 0;
298 }
299
300 static void mvebu_uart_shutdown(struct uart_port *port)
301 {
302 writel(0, port->membase + UART_CTRL);
303 }
304
305 static void mvebu_uart_set_termios(struct uart_port *port,
306 struct ktermios *termios,
307 struct ktermios *old)
308 {
309 unsigned long flags;
310 unsigned int baud;
311
312 spin_lock_irqsave(&port->lock, flags);
313
314 port->read_status_mask = STAT_RX_RDY | STAT_OVR_ERR |
315 STAT_TX_RDY | STAT_TX_FIFO_FUL;
316
317 if (termios->c_iflag & INPCK)
318 port->read_status_mask |= STAT_FRM_ERR | STAT_PAR_ERR;
319
320 port->ignore_status_mask = 0;
321 if (termios->c_iflag & IGNPAR)
322 port->ignore_status_mask |=
323 STAT_FRM_ERR | STAT_PAR_ERR | STAT_OVR_ERR;
324
325 if ((termios->c_cflag & CREAD) == 0)
326 port->ignore_status_mask |= STAT_RX_RDY | STAT_BRK_ERR;
327
328 if (old)
329 tty_termios_copy_hw(termios, old);
330
331 baud = uart_get_baud_rate(port, termios, old, 0, 460800);
332 uart_update_timeout(port, termios->c_cflag, baud);
333
334 spin_unlock_irqrestore(&port->lock, flags);
335 }
336
337 static const char *mvebu_uart_type(struct uart_port *port)
338 {
339 return MVEBU_UART_TYPE;
340 }
341
342 static void mvebu_uart_release_port(struct uart_port *port)
343 {
344 /* Nothing to do here */
345 }
346
347 static int mvebu_uart_request_port(struct uart_port *port)
348 {
349 return 0;
350 }
351
352 #ifdef CONFIG_CONSOLE_POLL
353 static int mvebu_uart_get_poll_char(struct uart_port *port)
354 {
355 unsigned int st = readl(port->membase + UART_STAT);
356
357 if (!(st & STAT_RX_RDY))
358 return NO_POLL_CHAR;
359
360 return readl(port->membase + UART_RBR);
361 }
362
363 static void mvebu_uart_put_poll_char(struct uart_port *port, unsigned char c)
364 {
365 unsigned int st;
366
367 for (;;) {
368 st = readl(port->membase + UART_STAT);
369
370 if (!(st & STAT_TX_FIFO_FUL))
371 break;
372
373 udelay(1);
374 }
375
376 writel(c, port->membase + UART_TSH);
377 }
378 #endif
379
380 static const struct uart_ops mvebu_uart_ops = {
381 .tx_empty = mvebu_uart_tx_empty,
382 .set_mctrl = mvebu_uart_set_mctrl,
383 .get_mctrl = mvebu_uart_get_mctrl,
384 .stop_tx = mvebu_uart_stop_tx,
385 .start_tx = mvebu_uart_start_tx,
386 .stop_rx = mvebu_uart_stop_rx,
387 .break_ctl = mvebu_uart_break_ctl,
388 .startup = mvebu_uart_startup,
389 .shutdown = mvebu_uart_shutdown,
390 .set_termios = mvebu_uart_set_termios,
391 .type = mvebu_uart_type,
392 .release_port = mvebu_uart_release_port,
393 .request_port = mvebu_uart_request_port,
394 #ifdef CONFIG_CONSOLE_POLL
395 .poll_get_char = mvebu_uart_get_poll_char,
396 .poll_put_char = mvebu_uart_put_poll_char,
397 #endif
398 };
399
400 /* Console Driver Operations */
401
402 #ifdef CONFIG_SERIAL_MVEBU_CONSOLE
403 /* Early Console */
404 static void mvebu_uart_putc(struct uart_port *port, int c)
405 {
406 unsigned int st;
407
408 for (;;) {
409 st = readl(port->membase + UART_STAT);
410 if (!(st & STAT_TX_FIFO_FUL))
411 break;
412 }
413
414 writel(c, port->membase + UART_TSH);
415
416 for (;;) {
417 st = readl(port->membase + UART_STAT);
418 if (st & STAT_TX_FIFO_EMP)
419 break;
420 }
421 }
422
423 static void mvebu_uart_putc_early_write(struct console *con,
424 const char *s,
425 unsigned n)
426 {
427 struct earlycon_device *dev = con->data;
428
429 uart_console_write(&dev->port, s, n, mvebu_uart_putc);
430 }
431
432 static int __init
433 mvebu_uart_early_console_setup(struct earlycon_device *device,
434 const char *opt)
435 {
436 if (!device->port.membase)
437 return -ENODEV;
438
439 device->con->write = mvebu_uart_putc_early_write;
440
441 return 0;
442 }
443
444 EARLYCON_DECLARE(ar3700_uart, mvebu_uart_early_console_setup);
445 OF_EARLYCON_DECLARE(ar3700_uart, "marvell,armada-3700-uart",
446 mvebu_uart_early_console_setup);
447
448 static void wait_for_xmitr(struct uart_port *port)
449 {
450 u32 val;
451
452 readl_poll_timeout_atomic(port->membase + UART_STAT, val,
453 (val & STAT_TX_EMP), 1, 10000);
454 }
455
456 static void mvebu_uart_console_putchar(struct uart_port *port, int ch)
457 {
458 wait_for_xmitr(port);
459 writel(ch, port->membase + UART_TSH);
460 }
461
462 static void mvebu_uart_console_write(struct console *co, const char *s,
463 unsigned int count)
464 {
465 struct uart_port *port = &mvebu_uart_ports[co->index];
466 unsigned long flags;
467 unsigned int ier;
468 int locked = 1;
469
470 if (oops_in_progress)
471 locked = spin_trylock_irqsave(&port->lock, flags);
472 else
473 spin_lock_irqsave(&port->lock, flags);
474
475 ier = readl(port->membase + UART_CTRL) &
476 (CTRL_RX_INT | CTRL_TX_RDY_INT);
477 writel(0, port->membase + UART_CTRL);
478
479 uart_console_write(port, s, count, mvebu_uart_console_putchar);
480
481 wait_for_xmitr(port);
482
483 if (ier)
484 writel(ier, port->membase + UART_CTRL);
485
486 if (locked)
487 spin_unlock_irqrestore(&port->lock, flags);
488 }
489
490 static int mvebu_uart_console_setup(struct console *co, char *options)
491 {
492 struct uart_port *port;
493 int baud = 9600;
494 int bits = 8;
495 int parity = 'n';
496 int flow = 'n';
497
498 if (co->index < 0 || co->index >= MVEBU_NR_UARTS)
499 return -EINVAL;
500
501 port = &mvebu_uart_ports[co->index];
502
503 if (!port->mapbase || !port->membase) {
504 pr_debug("console on ttyMV%i not present\n", co->index);
505 return -ENODEV;
506 }
507
508 if (options)
509 uart_parse_options(options, &baud, &parity, &bits, &flow);
510
511 return uart_set_options(port, co, baud, parity, bits, flow);
512 }
513
514 static struct uart_driver mvebu_uart_driver;
515
516 static struct console mvebu_uart_console = {
517 .name = "ttyMV",
518 .write = mvebu_uart_console_write,
519 .device = uart_console_device,
520 .setup = mvebu_uart_console_setup,
521 .flags = CON_PRINTBUFFER,
522 .index = -1,
523 .data = &mvebu_uart_driver,
524 };
525
526 static int __init mvebu_uart_console_init(void)
527 {
528 register_console(&mvebu_uart_console);
529 return 0;
530 }
531
532 console_initcall(mvebu_uart_console_init);
533
534
535 #endif /* CONFIG_SERIAL_MVEBU_CONSOLE */
536
537 static struct uart_driver mvebu_uart_driver = {
538 .owner = THIS_MODULE,
539 .driver_name = "mvebu_serial",
540 .dev_name = "ttyMV",
541 .nr = MVEBU_NR_UARTS,
542 #ifdef CONFIG_SERIAL_MVEBU_CONSOLE
543 .cons = &mvebu_uart_console,
544 #endif
545 };
546
547 static int mvebu_uart_probe(struct platform_device *pdev)
548 {
549 struct resource *reg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
550 struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
551 struct uart_port *port;
552 struct mvebu_uart_data *data;
553 int ret;
554
555 if (!reg || !irq) {
556 dev_err(&pdev->dev, "no registers/irq defined\n");
557 return -EINVAL;
558 }
559
560 port = &mvebu_uart_ports[0];
561
562 spin_lock_init(&port->lock);
563
564 port->dev = &pdev->dev;
565 port->type = PORT_MVEBU;
566 port->ops = &mvebu_uart_ops;
567 port->regshift = 0;
568
569 port->fifosize = 32;
570 port->iotype = UPIO_MEM32;
571 port->flags = UPF_FIXED_PORT;
572 port->line = 0; /* single port: force line number to 0 */
573
574 port->irq = irq->start;
575 port->irqflags = 0;
576 port->mapbase = reg->start;
577
578 port->membase = devm_ioremap_resource(&pdev->dev, reg);
579 if (IS_ERR(port->membase))
580 return -PTR_ERR(port->membase);
581
582 data = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_uart_data),
583 GFP_KERNEL);
584 if (!data)
585 return -ENOMEM;
586
587 data->port = port;
588
589 port->private_data = data;
590 platform_set_drvdata(pdev, data);
591
592 ret = uart_add_one_port(&mvebu_uart_driver, port);
593 if (ret)
594 return ret;
595 return 0;
596 }
597
598 /* Match table for of_platform binding */
599 static const struct of_device_id mvebu_uart_of_match[] = {
600 { .compatible = "marvell,armada-3700-uart", },
601 {}
602 };
603
604 static struct platform_driver mvebu_uart_platform_driver = {
605 .probe = mvebu_uart_probe,
606 .driver = {
607 .name = "mvebu-uart",
608 .of_match_table = of_match_ptr(mvebu_uart_of_match),
609 .suppress_bind_attrs = true,
610 },
611 };
612
613 static int __init mvebu_uart_init(void)
614 {
615 int ret;
616
617 ret = uart_register_driver(&mvebu_uart_driver);
618 if (ret)
619 return ret;
620
621 ret = platform_driver_register(&mvebu_uart_platform_driver);
622 if (ret)
623 uart_unregister_driver(&mvebu_uart_driver);
624
625 return ret;
626 }
627 arch_initcall(mvebu_uart_init);
Linux with added FPC-III support