xref: /openbmc/linux/drivers/tty/serial/lantiq.c (revision 6fe888c4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
4  *
5  * Copyright (C) 2004 Infineon IFAP DC COM CPE
6  * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
7  * Copyright (C) 2007 John Crispin <john@phrozen.org>
8  * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
9  */
10 
11 #include <linux/bitfield.h>
12 #include <linux/clk.h>
13 #include <linux/console.h>
14 #include <linux/device.h>
15 #include <linux/init.h>
16 #include <linux/io.h>
17 #include <linux/ioport.h>
18 #include <linux/lantiq.h>
19 #include <linux/module.h>
20 #include <linux/of_platform.h>
21 #include <linux/serial.h>
22 #include <linux/serial_core.h>
23 #include <linux/slab.h>
24 #include <linux/sysrq.h>
25 #include <linux/tty.h>
26 #include <linux/tty_flip.h>
27 
28 #define PORT_LTQ_ASC		111
29 #define MAXPORTS		2
30 #define UART_DUMMY_UER_RX	1
31 #define DRVNAME			"lantiq,asc"
32 #ifdef __BIG_ENDIAN
33 #define LTQ_ASC_TBUF		(0x0020 + 3)
34 #define LTQ_ASC_RBUF		(0x0024 + 3)
35 #else
36 #define LTQ_ASC_TBUF		0x0020
37 #define LTQ_ASC_RBUF		0x0024
38 #endif
39 #define LTQ_ASC_FSTAT		0x0048
40 #define LTQ_ASC_WHBSTATE	0x0018
41 #define LTQ_ASC_STATE		0x0014
42 #define LTQ_ASC_IRNCR		0x00F8
43 #define LTQ_ASC_CLC		0x0000
44 #define LTQ_ASC_ID		0x0008
45 #define LTQ_ASC_PISEL		0x0004
46 #define LTQ_ASC_TXFCON		0x0044
47 #define LTQ_ASC_RXFCON		0x0040
48 #define LTQ_ASC_CON		0x0010
49 #define LTQ_ASC_BG		0x0050
50 #define LTQ_ASC_IRNREN		0x00F4
51 
52 #define ASC_IRNREN_TX		0x1
53 #define ASC_IRNREN_RX		0x2
54 #define ASC_IRNREN_ERR		0x4
55 #define ASC_IRNREN_TX_BUF	0x8
56 #define ASC_IRNCR_TIR		0x1
57 #define ASC_IRNCR_RIR		0x2
58 #define ASC_IRNCR_EIR		0x4
59 #define ASC_IRNCR_MASK		GENMASK(2, 0)
60 
61 #define ASCOPT_CSIZE		0x3
62 #define TXFIFO_FL		1
63 #define RXFIFO_FL		1
64 #define ASCCLC_DISS		0x2
65 #define ASCCLC_RMCMASK		0x0000FF00
66 #define ASCCLC_RMCOFFSET	8
67 #define ASCCON_M_8ASYNC		0x0
68 #define ASCCON_M_7ASYNC		0x2
69 #define ASCCON_ODD		0x00000020
70 #define ASCCON_STP		0x00000080
71 #define ASCCON_BRS		0x00000100
72 #define ASCCON_FDE		0x00000200
73 #define ASCCON_R		0x00008000
74 #define ASCCON_FEN		0x00020000
75 #define ASCCON_ROEN		0x00080000
76 #define ASCCON_TOEN		0x00100000
77 #define ASCSTATE_PE		0x00010000
78 #define ASCSTATE_FE		0x00020000
79 #define ASCSTATE_ROE		0x00080000
80 #define ASCSTATE_ANY		(ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
81 #define ASCWHBSTATE_CLRREN	0x00000001
82 #define ASCWHBSTATE_SETREN	0x00000002
83 #define ASCWHBSTATE_CLRPE	0x00000004
84 #define ASCWHBSTATE_CLRFE	0x00000008
85 #define ASCWHBSTATE_CLRROE	0x00000020
86 #define ASCTXFCON_TXFEN		0x0001
87 #define ASCTXFCON_TXFFLU	0x0002
88 #define ASCTXFCON_TXFITLMASK	0x3F00
89 #define ASCTXFCON_TXFITLOFF	8
90 #define ASCRXFCON_RXFEN		0x0001
91 #define ASCRXFCON_RXFFLU	0x0002
92 #define ASCRXFCON_RXFITLMASK	0x3F00
93 #define ASCRXFCON_RXFITLOFF	8
94 #define ASCFSTAT_RXFFLMASK	0x003F
95 #define ASCFSTAT_TXFFLMASK	0x3F00
96 #define ASCFSTAT_TXFREEMASK	0x3F000000
97 
98 static void lqasc_tx_chars(struct uart_port *port);
99 static struct ltq_uart_port *lqasc_port[MAXPORTS];
100 static struct uart_driver lqasc_reg;
101 
102 struct ltq_soc_data {
103 	int	(*fetch_irq)(struct device *dev, struct ltq_uart_port *ltq_port);
104 	int	(*request_irq)(struct uart_port *port);
105 	void	(*free_irq)(struct uart_port *port);
106 };
107 
108 struct ltq_uart_port {
109 	struct uart_port	port;
110 	/* clock used to derive divider */
111 	struct clk		*freqclk;
112 	/* clock gating of the ASC core */
113 	struct clk		*clk;
114 	unsigned int		tx_irq;
115 	unsigned int		rx_irq;
116 	unsigned int		err_irq;
117 	unsigned int		common_irq;
118 	spinlock_t		lock; /* exclusive access for multi core */
119 
120 	const struct ltq_soc_data	*soc;
121 };
122 
123 static inline void asc_update_bits(u32 clear, u32 set, void __iomem *reg)
124 {
125 	u32 tmp = __raw_readl(reg);
126 
127 	__raw_writel((tmp & ~clear) | set, reg);
128 }
129 
130 static inline struct
131 ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
132 {
133 	return container_of(port, struct ltq_uart_port, port);
134 }
135 
136 static void
137 lqasc_stop_tx(struct uart_port *port)
138 {
139 	return;
140 }
141 
142 static bool lqasc_tx_ready(struct uart_port *port)
143 {
144 	u32 fstat = __raw_readl(port->membase + LTQ_ASC_FSTAT);
145 
146 	return FIELD_GET(ASCFSTAT_TXFREEMASK, fstat);
147 }
148 
149 static void
150 lqasc_start_tx(struct uart_port *port)
151 {
152 	unsigned long flags;
153 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
154 
155 	spin_lock_irqsave(&ltq_port->lock, flags);
156 	lqasc_tx_chars(port);
157 	spin_unlock_irqrestore(&ltq_port->lock, flags);
158 	return;
159 }
160 
161 static void
162 lqasc_stop_rx(struct uart_port *port)
163 {
164 	__raw_writel(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
165 }
166 
167 static int
168 lqasc_rx_chars(struct uart_port *port)
169 {
170 	struct tty_port *tport = &port->state->port;
171 	unsigned int ch = 0, rsr = 0, fifocnt;
172 
173 	fifocnt = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
174 		  ASCFSTAT_RXFFLMASK;
175 	while (fifocnt--) {
176 		u8 flag = TTY_NORMAL;
177 		ch = readb(port->membase + LTQ_ASC_RBUF);
178 		rsr = (__raw_readl(port->membase + LTQ_ASC_STATE)
179 			& ASCSTATE_ANY) | UART_DUMMY_UER_RX;
180 		tty_flip_buffer_push(tport);
181 		port->icount.rx++;
182 
183 		/*
184 		 * Note that the error handling code is
185 		 * out of the main execution path
186 		 */
187 		if (rsr & ASCSTATE_ANY) {
188 			if (rsr & ASCSTATE_PE) {
189 				port->icount.parity++;
190 				asc_update_bits(0, ASCWHBSTATE_CLRPE,
191 					port->membase + LTQ_ASC_WHBSTATE);
192 			} else if (rsr & ASCSTATE_FE) {
193 				port->icount.frame++;
194 				asc_update_bits(0, ASCWHBSTATE_CLRFE,
195 					port->membase + LTQ_ASC_WHBSTATE);
196 			}
197 			if (rsr & ASCSTATE_ROE) {
198 				port->icount.overrun++;
199 				asc_update_bits(0, ASCWHBSTATE_CLRROE,
200 					port->membase + LTQ_ASC_WHBSTATE);
201 			}
202 
203 			rsr &= port->read_status_mask;
204 
205 			if (rsr & ASCSTATE_PE)
206 				flag = TTY_PARITY;
207 			else if (rsr & ASCSTATE_FE)
208 				flag = TTY_FRAME;
209 		}
210 
211 		if ((rsr & port->ignore_status_mask) == 0)
212 			tty_insert_flip_char(tport, ch, flag);
213 
214 		if (rsr & ASCSTATE_ROE)
215 			/*
216 			 * Overrun is special, since it's reported
217 			 * immediately, and doesn't affect the current
218 			 * character
219 			 */
220 			tty_insert_flip_char(tport, 0, TTY_OVERRUN);
221 	}
222 
223 	if (ch != 0)
224 		tty_flip_buffer_push(tport);
225 
226 	return 0;
227 }
228 
229 static void
230 lqasc_tx_chars(struct uart_port *port)
231 {
232 	struct circ_buf *xmit = &port->state->xmit;
233 	if (uart_tx_stopped(port)) {
234 		lqasc_stop_tx(port);
235 		return;
236 	}
237 
238 	while (lqasc_tx_ready(port)) {
239 		if (port->x_char) {
240 			writeb(port->x_char, port->membase + LTQ_ASC_TBUF);
241 			port->icount.tx++;
242 			port->x_char = 0;
243 			continue;
244 		}
245 
246 		if (uart_circ_empty(xmit))
247 			break;
248 
249 		writeb(port->state->xmit.buf[port->state->xmit.tail],
250 			port->membase + LTQ_ASC_TBUF);
251 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
252 		port->icount.tx++;
253 	}
254 
255 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
256 		uart_write_wakeup(port);
257 }
258 
259 static irqreturn_t
260 lqasc_tx_int(int irq, void *_port)
261 {
262 	unsigned long flags;
263 	struct uart_port *port = (struct uart_port *)_port;
264 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
265 
266 	spin_lock_irqsave(&ltq_port->lock, flags);
267 	__raw_writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
268 	spin_unlock_irqrestore(&ltq_port->lock, flags);
269 	lqasc_start_tx(port);
270 	return IRQ_HANDLED;
271 }
272 
273 static irqreturn_t
274 lqasc_err_int(int irq, void *_port)
275 {
276 	unsigned long flags;
277 	struct uart_port *port = (struct uart_port *)_port;
278 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
279 
280 	spin_lock_irqsave(&ltq_port->lock, flags);
281 	/* clear any pending interrupts */
282 	asc_update_bits(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
283 		ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
284 	spin_unlock_irqrestore(&ltq_port->lock, flags);
285 	return IRQ_HANDLED;
286 }
287 
288 static irqreturn_t
289 lqasc_rx_int(int irq, void *_port)
290 {
291 	unsigned long flags;
292 	struct uart_port *port = (struct uart_port *)_port;
293 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
294 
295 	spin_lock_irqsave(&ltq_port->lock, flags);
296 	__raw_writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
297 	lqasc_rx_chars(port);
298 	spin_unlock_irqrestore(&ltq_port->lock, flags);
299 	return IRQ_HANDLED;
300 }
301 
302 static irqreturn_t lqasc_irq(int irq, void *p)
303 {
304 	unsigned long flags;
305 	u32 stat;
306 	struct uart_port *port = p;
307 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
308 
309 	spin_lock_irqsave(&ltq_port->lock, flags);
310 	stat = readl(port->membase + LTQ_ASC_IRNCR);
311 	spin_unlock_irqrestore(&ltq_port->lock, flags);
312 	if (!(stat & ASC_IRNCR_MASK))
313 		return IRQ_NONE;
314 
315 	if (stat & ASC_IRNCR_TIR)
316 		lqasc_tx_int(irq, p);
317 
318 	if (stat & ASC_IRNCR_RIR)
319 		lqasc_rx_int(irq, p);
320 
321 	if (stat & ASC_IRNCR_EIR)
322 		lqasc_err_int(irq, p);
323 
324 	return IRQ_HANDLED;
325 }
326 
327 static unsigned int
328 lqasc_tx_empty(struct uart_port *port)
329 {
330 	int status;
331 	status = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
332 		 ASCFSTAT_TXFFLMASK;
333 	return status ? 0 : TIOCSER_TEMT;
334 }
335 
336 static unsigned int
337 lqasc_get_mctrl(struct uart_port *port)
338 {
339 	return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR;
340 }
341 
342 static void
343 lqasc_set_mctrl(struct uart_port *port, u_int mctrl)
344 {
345 }
346 
347 static void
348 lqasc_break_ctl(struct uart_port *port, int break_state)
349 {
350 }
351 
352 static int
353 lqasc_startup(struct uart_port *port)
354 {
355 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
356 	int retval;
357 	unsigned long flags;
358 
359 	if (!IS_ERR(ltq_port->clk))
360 		clk_prepare_enable(ltq_port->clk);
361 	port->uartclk = clk_get_rate(ltq_port->freqclk);
362 
363 	spin_lock_irqsave(&ltq_port->lock, flags);
364 	asc_update_bits(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
365 		port->membase + LTQ_ASC_CLC);
366 
367 	__raw_writel(0, port->membase + LTQ_ASC_PISEL);
368 	__raw_writel(
369 		((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
370 		ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
371 		port->membase + LTQ_ASC_TXFCON);
372 	__raw_writel(
373 		((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
374 		| ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
375 		port->membase + LTQ_ASC_RXFCON);
376 	/* make sure other settings are written to hardware before
377 	 * setting enable bits
378 	 */
379 	wmb();
380 	asc_update_bits(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
381 		ASCCON_ROEN, port->membase + LTQ_ASC_CON);
382 
383 	spin_unlock_irqrestore(&ltq_port->lock, flags);
384 
385 	retval = ltq_port->soc->request_irq(port);
386 	if (retval)
387 		return retval;
388 
389 	__raw_writel(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
390 		port->membase + LTQ_ASC_IRNREN);
391 	return retval;
392 }
393 
394 static void
395 lqasc_shutdown(struct uart_port *port)
396 {
397 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
398 	unsigned long flags;
399 
400 	ltq_port->soc->free_irq(port);
401 
402 	spin_lock_irqsave(&ltq_port->lock, flags);
403 	__raw_writel(0, port->membase + LTQ_ASC_CON);
404 	asc_update_bits(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
405 		port->membase + LTQ_ASC_RXFCON);
406 	asc_update_bits(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
407 		port->membase + LTQ_ASC_TXFCON);
408 	spin_unlock_irqrestore(&ltq_port->lock, flags);
409 	if (!IS_ERR(ltq_port->clk))
410 		clk_disable_unprepare(ltq_port->clk);
411 }
412 
413 static void
414 lqasc_set_termios(struct uart_port *port, struct ktermios *new,
415 		  const struct ktermios *old)
416 {
417 	unsigned int cflag;
418 	unsigned int iflag;
419 	unsigned int divisor;
420 	unsigned int baud;
421 	unsigned int con = 0;
422 	unsigned long flags;
423 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
424 
425 	cflag = new->c_cflag;
426 	iflag = new->c_iflag;
427 
428 	switch (cflag & CSIZE) {
429 	case CS7:
430 		con = ASCCON_M_7ASYNC;
431 		break;
432 
433 	case CS5:
434 	case CS6:
435 	default:
436 		new->c_cflag &= ~ CSIZE;
437 		new->c_cflag |= CS8;
438 		con = ASCCON_M_8ASYNC;
439 		break;
440 	}
441 
442 	cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
443 
444 	if (cflag & CSTOPB)
445 		con |= ASCCON_STP;
446 
447 	if (cflag & PARENB) {
448 		if (!(cflag & PARODD))
449 			con &= ~ASCCON_ODD;
450 		else
451 			con |= ASCCON_ODD;
452 	}
453 
454 	port->read_status_mask = ASCSTATE_ROE;
455 	if (iflag & INPCK)
456 		port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
457 
458 	port->ignore_status_mask = 0;
459 	if (iflag & IGNPAR)
460 		port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
461 
462 	if (iflag & IGNBRK) {
463 		/*
464 		 * If we're ignoring parity and break indicators,
465 		 * ignore overruns too (for real raw support).
466 		 */
467 		if (iflag & IGNPAR)
468 			port->ignore_status_mask |= ASCSTATE_ROE;
469 	}
470 
471 	if ((cflag & CREAD) == 0)
472 		port->ignore_status_mask |= UART_DUMMY_UER_RX;
473 
474 	/* set error signals  - framing, parity  and overrun, enable receiver */
475 	con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
476 
477 	spin_lock_irqsave(&ltq_port->lock, flags);
478 
479 	/* set up CON */
480 	asc_update_bits(0, con, port->membase + LTQ_ASC_CON);
481 
482 	/* Set baud rate - take a divider of 2 into account */
483 	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
484 	divisor = uart_get_divisor(port, baud);
485 	divisor = divisor / 2 - 1;
486 
487 	/* disable the baudrate generator */
488 	asc_update_bits(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
489 
490 	/* make sure the fractional divider is off */
491 	asc_update_bits(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
492 
493 	/* set up to use divisor of 2 */
494 	asc_update_bits(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
495 
496 	/* now we can write the new baudrate into the register */
497 	__raw_writel(divisor, port->membase + LTQ_ASC_BG);
498 
499 	/* turn the baudrate generator back on */
500 	asc_update_bits(0, ASCCON_R, port->membase + LTQ_ASC_CON);
501 
502 	/* enable rx */
503 	__raw_writel(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
504 
505 	spin_unlock_irqrestore(&ltq_port->lock, flags);
506 
507 	/* Don't rewrite B0 */
508 	if (tty_termios_baud_rate(new))
509 		tty_termios_encode_baud_rate(new, baud, baud);
510 
511 	uart_update_timeout(port, cflag, baud);
512 }
513 
514 static const char*
515 lqasc_type(struct uart_port *port)
516 {
517 	if (port->type == PORT_LTQ_ASC)
518 		return DRVNAME;
519 	else
520 		return NULL;
521 }
522 
523 static void
524 lqasc_release_port(struct uart_port *port)
525 {
526 	struct platform_device *pdev = to_platform_device(port->dev);
527 
528 	if (port->flags & UPF_IOREMAP) {
529 		devm_iounmap(&pdev->dev, port->membase);
530 		port->membase = NULL;
531 	}
532 }
533 
534 static int
535 lqasc_request_port(struct uart_port *port)
536 {
537 	struct platform_device *pdev = to_platform_device(port->dev);
538 	struct resource *res;
539 	int size;
540 
541 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
542 	if (!res) {
543 		dev_err(&pdev->dev, "cannot obtain I/O memory region");
544 		return -ENODEV;
545 	}
546 	size = resource_size(res);
547 
548 	res = devm_request_mem_region(&pdev->dev, res->start,
549 		size, dev_name(&pdev->dev));
550 	if (!res) {
551 		dev_err(&pdev->dev, "cannot request I/O memory region");
552 		return -EBUSY;
553 	}
554 
555 	if (port->flags & UPF_IOREMAP) {
556 		port->membase = devm_ioremap(&pdev->dev,
557 			port->mapbase, size);
558 		if (port->membase == NULL)
559 			return -ENOMEM;
560 	}
561 	return 0;
562 }
563 
564 static void
565 lqasc_config_port(struct uart_port *port, int flags)
566 {
567 	if (flags & UART_CONFIG_TYPE) {
568 		port->type = PORT_LTQ_ASC;
569 		lqasc_request_port(port);
570 	}
571 }
572 
573 static int
574 lqasc_verify_port(struct uart_port *port,
575 	struct serial_struct *ser)
576 {
577 	int ret = 0;
578 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC)
579 		ret = -EINVAL;
580 	if (ser->irq < 0 || ser->irq >= NR_IRQS)
581 		ret = -EINVAL;
582 	if (ser->baud_base < 9600)
583 		ret = -EINVAL;
584 	return ret;
585 }
586 
587 static const struct uart_ops lqasc_pops = {
588 	.tx_empty =	lqasc_tx_empty,
589 	.set_mctrl =	lqasc_set_mctrl,
590 	.get_mctrl =	lqasc_get_mctrl,
591 	.stop_tx =	lqasc_stop_tx,
592 	.start_tx =	lqasc_start_tx,
593 	.stop_rx =	lqasc_stop_rx,
594 	.break_ctl =	lqasc_break_ctl,
595 	.startup =	lqasc_startup,
596 	.shutdown =	lqasc_shutdown,
597 	.set_termios =	lqasc_set_termios,
598 	.type =		lqasc_type,
599 	.release_port =	lqasc_release_port,
600 	.request_port =	lqasc_request_port,
601 	.config_port =	lqasc_config_port,
602 	.verify_port =	lqasc_verify_port,
603 };
604 
605 #ifdef CONFIG_SERIAL_LANTIQ_CONSOLE
606 static void
607 lqasc_console_putchar(struct uart_port *port, unsigned char ch)
608 {
609 	if (!port->membase)
610 		return;
611 
612 	while (!lqasc_tx_ready(port))
613 		;
614 
615 	writeb(ch, port->membase + LTQ_ASC_TBUF);
616 }
617 
618 static void lqasc_serial_port_write(struct uart_port *port, const char *s,
619 				    u_int count)
620 {
621 	uart_console_write(port, s, count, lqasc_console_putchar);
622 }
623 
624 static void
625 lqasc_console_write(struct console *co, const char *s, u_int count)
626 {
627 	struct ltq_uart_port *ltq_port;
628 	unsigned long flags;
629 
630 	if (co->index >= MAXPORTS)
631 		return;
632 
633 	ltq_port = lqasc_port[co->index];
634 	if (!ltq_port)
635 		return;
636 
637 	spin_lock_irqsave(&ltq_port->lock, flags);
638 	lqasc_serial_port_write(&ltq_port->port, s, count);
639 	spin_unlock_irqrestore(&ltq_port->lock, flags);
640 }
641 
642 static int __init
643 lqasc_console_setup(struct console *co, char *options)
644 {
645 	struct ltq_uart_port *ltq_port;
646 	struct uart_port *port;
647 	int baud = 115200;
648 	int bits = 8;
649 	int parity = 'n';
650 	int flow = 'n';
651 
652 	if (co->index >= MAXPORTS)
653 		return -ENODEV;
654 
655 	ltq_port = lqasc_port[co->index];
656 	if (!ltq_port)
657 		return -ENODEV;
658 
659 	port = &ltq_port->port;
660 
661 	if (!IS_ERR(ltq_port->clk))
662 		clk_prepare_enable(ltq_port->clk);
663 
664 	port->uartclk = clk_get_rate(ltq_port->freqclk);
665 
666 	if (options)
667 		uart_parse_options(options, &baud, &parity, &bits, &flow);
668 	return uart_set_options(port, co, baud, parity, bits, flow);
669 }
670 
671 static struct console lqasc_console = {
672 	.name =		"ttyLTQ",
673 	.write =	lqasc_console_write,
674 	.device =	uart_console_device,
675 	.setup =	lqasc_console_setup,
676 	.flags =	CON_PRINTBUFFER,
677 	.index =	-1,
678 	.data =		&lqasc_reg,
679 };
680 
681 static int __init
682 lqasc_console_init(void)
683 {
684 	register_console(&lqasc_console);
685 	return 0;
686 }
687 console_initcall(lqasc_console_init);
688 
689 static void lqasc_serial_early_console_write(struct console *co,
690 					     const char *s,
691 					     u_int count)
692 {
693 	struct earlycon_device *dev = co->data;
694 
695 	lqasc_serial_port_write(&dev->port, s, count);
696 }
697 
698 static int __init
699 lqasc_serial_early_console_setup(struct earlycon_device *device,
700 				 const char *opt)
701 {
702 	if (!device->port.membase)
703 		return -ENODEV;
704 
705 	device->con->write = lqasc_serial_early_console_write;
706 	return 0;
707 }
708 OF_EARLYCON_DECLARE(lantiq, "lantiq,asc", lqasc_serial_early_console_setup);
709 OF_EARLYCON_DECLARE(lantiq, "intel,lgm-asc", lqasc_serial_early_console_setup);
710 
711 #define LANTIQ_SERIAL_CONSOLE	(&lqasc_console)
712 
713 #else
714 
715 #define LANTIQ_SERIAL_CONSOLE	NULL
716 
717 #endif /* CONFIG_SERIAL_LANTIQ_CONSOLE */
718 
719 static struct uart_driver lqasc_reg = {
720 	.owner =	THIS_MODULE,
721 	.driver_name =	DRVNAME,
722 	.dev_name =	"ttyLTQ",
723 	.major =	0,
724 	.minor =	0,
725 	.nr =		MAXPORTS,
726 	.cons =		LANTIQ_SERIAL_CONSOLE,
727 };
728 
729 static int fetch_irq_lantiq(struct device *dev, struct ltq_uart_port *ltq_port)
730 {
731 	struct uart_port *port = &ltq_port->port;
732 	struct platform_device *pdev = to_platform_device(dev);
733 	int irq;
734 
735 	irq = platform_get_irq(pdev, 0);
736 	if (irq < 0)
737 		return irq;
738 	ltq_port->tx_irq = irq;
739 	irq = platform_get_irq(pdev, 1);
740 	if (irq < 0)
741 		return irq;
742 	ltq_port->rx_irq = irq;
743 	irq = platform_get_irq(pdev, 2);
744 	if (irq < 0)
745 		return irq;
746 	ltq_port->err_irq = irq;
747 
748 	port->irq = ltq_port->tx_irq;
749 
750 	return 0;
751 }
752 
753 static int request_irq_lantiq(struct uart_port *port)
754 {
755 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
756 	int retval;
757 
758 	retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
759 			     0, "asc_tx", port);
760 	if (retval) {
761 		dev_err(port->dev, "failed to request asc_tx\n");
762 		return retval;
763 	}
764 
765 	retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
766 			     0, "asc_rx", port);
767 	if (retval) {
768 		dev_err(port->dev, "failed to request asc_rx\n");
769 		goto err1;
770 	}
771 
772 	retval = request_irq(ltq_port->err_irq, lqasc_err_int,
773 			     0, "asc_err", port);
774 	if (retval) {
775 		dev_err(port->dev, "failed to request asc_err\n");
776 		goto err2;
777 	}
778 	return 0;
779 
780 err2:
781 	free_irq(ltq_port->rx_irq, port);
782 err1:
783 	free_irq(ltq_port->tx_irq, port);
784 	return retval;
785 }
786 
787 static void free_irq_lantiq(struct uart_port *port)
788 {
789 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
790 
791 	free_irq(ltq_port->tx_irq, port);
792 	free_irq(ltq_port->rx_irq, port);
793 	free_irq(ltq_port->err_irq, port);
794 }
795 
796 static int fetch_irq_intel(struct device *dev, struct ltq_uart_port *ltq_port)
797 {
798 	struct uart_port *port = &ltq_port->port;
799 	int ret;
800 
801 	ret = platform_get_irq(to_platform_device(dev), 0);
802 	if (ret < 0) {
803 		dev_err(dev, "failed to fetch IRQ for serial port\n");
804 		return ret;
805 	}
806 	ltq_port->common_irq = ret;
807 	port->irq = ret;
808 
809 	return 0;
810 }
811 
812 static int request_irq_intel(struct uart_port *port)
813 {
814 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
815 	int retval;
816 
817 	retval = request_irq(ltq_port->common_irq, lqasc_irq, 0,
818 			     "asc_irq", port);
819 	if (retval)
820 		dev_err(port->dev, "failed to request asc_irq\n");
821 
822 	return retval;
823 }
824 
825 static void free_irq_intel(struct uart_port *port)
826 {
827 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
828 
829 	free_irq(ltq_port->common_irq, port);
830 }
831 
832 static int lqasc_probe(struct platform_device *pdev)
833 {
834 	struct device_node *node = pdev->dev.of_node;
835 	struct ltq_uart_port *ltq_port;
836 	struct uart_port *port;
837 	struct resource *mmres;
838 	int line;
839 	int ret;
840 
841 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
842 	if (!mmres) {
843 		dev_err(&pdev->dev,
844 			"failed to get memory for serial port\n");
845 		return -ENODEV;
846 	}
847 
848 	ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
849 				GFP_KERNEL);
850 	if (!ltq_port)
851 		return -ENOMEM;
852 
853 	port = &ltq_port->port;
854 
855 	ltq_port->soc = of_device_get_match_data(&pdev->dev);
856 	ret = ltq_port->soc->fetch_irq(&pdev->dev, ltq_port);
857 	if (ret)
858 		return ret;
859 
860 	/* get serial id */
861 	line = of_alias_get_id(node, "serial");
862 	if (line < 0) {
863 		if (IS_ENABLED(CONFIG_LANTIQ)) {
864 			if (mmres->start == CPHYSADDR(LTQ_EARLY_ASC))
865 				line = 0;
866 			else
867 				line = 1;
868 		} else {
869 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
870 				line);
871 			return line;
872 		}
873 	}
874 
875 	if (lqasc_port[line]) {
876 		dev_err(&pdev->dev, "port %d already allocated\n", line);
877 		return -EBUSY;
878 	}
879 
880 	port->iotype	= SERIAL_IO_MEM;
881 	port->flags	= UPF_BOOT_AUTOCONF | UPF_IOREMAP;
882 	port->ops	= &lqasc_pops;
883 	port->fifosize	= 16;
884 	port->type	= PORT_LTQ_ASC;
885 	port->line	= line;
886 	port->dev	= &pdev->dev;
887 	/* unused, just to be backward-compatible */
888 	port->mapbase	= mmres->start;
889 
890 	if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
891 		ltq_port->freqclk = clk_get_fpi();
892 	else
893 		ltq_port->freqclk = devm_clk_get(&pdev->dev, "freq");
894 
895 
896 	if (IS_ERR(ltq_port->freqclk)) {
897 		pr_err("failed to get fpi clk\n");
898 		return -ENOENT;
899 	}
900 
901 	/* not all asc ports have clock gates, lets ignore the return code */
902 	if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
903 		ltq_port->clk = clk_get(&pdev->dev, NULL);
904 	else
905 		ltq_port->clk = devm_clk_get(&pdev->dev, "asc");
906 
907 	spin_lock_init(&ltq_port->lock);
908 	lqasc_port[line] = ltq_port;
909 	platform_set_drvdata(pdev, ltq_port);
910 
911 	ret = uart_add_one_port(&lqasc_reg, port);
912 
913 	return ret;
914 }
915 
916 static int lqasc_remove(struct platform_device *pdev)
917 {
918 	struct uart_port *port = platform_get_drvdata(pdev);
919 
920 	return uart_remove_one_port(&lqasc_reg, port);
921 }
922 
923 static const struct ltq_soc_data soc_data_lantiq = {
924 	.fetch_irq = fetch_irq_lantiq,
925 	.request_irq = request_irq_lantiq,
926 	.free_irq = free_irq_lantiq,
927 };
928 
929 static const struct ltq_soc_data soc_data_intel = {
930 	.fetch_irq = fetch_irq_intel,
931 	.request_irq = request_irq_intel,
932 	.free_irq = free_irq_intel,
933 };
934 
935 static const struct of_device_id ltq_asc_match[] = {
936 	{ .compatible = "lantiq,asc", .data = &soc_data_lantiq },
937 	{ .compatible = "intel,lgm-asc", .data = &soc_data_intel },
938 	{},
939 };
940 MODULE_DEVICE_TABLE(of, ltq_asc_match);
941 
942 static struct platform_driver lqasc_driver = {
943 	.probe		= lqasc_probe,
944 	.remove		= lqasc_remove,
945 	.driver		= {
946 		.name	= DRVNAME,
947 		.of_match_table = ltq_asc_match,
948 	},
949 };
950 
951 static int __init
952 init_lqasc(void)
953 {
954 	int ret;
955 
956 	ret = uart_register_driver(&lqasc_reg);
957 	if (ret != 0)
958 		return ret;
959 
960 	ret = platform_driver_register(&lqasc_driver);
961 	if (ret != 0)
962 		uart_unregister_driver(&lqasc_reg);
963 
964 	return ret;
965 }
966 
967 static void __exit exit_lqasc(void)
968 {
969 	platform_driver_unregister(&lqasc_driver);
970 	uart_unregister_driver(&lqasc_reg);
971 }
972 
973 module_init(init_lqasc);
974 module_exit(exit_lqasc);
975 
976 MODULE_DESCRIPTION("Serial driver for Lantiq & Intel gateway SoCs");
977 MODULE_LICENSE("GPL v2");
978