xref: /openbmc/linux/drivers/tty/serial/lantiq.c (revision 5c816641) 
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/clk.h>
12 #include <linux/console.h>
13 #include <linux/device.h>
14 #include <linux/init.h>
15 #include <linux/io.h>
16 #include <linux/ioport.h>
17 #include <linux/lantiq.h>
18 #include <linux/module.h>
19 #include <linux/of_platform.h>
20 #include <linux/serial.h>
21 #include <linux/serial_core.h>
22 #include <linux/slab.h>
23 #include <linux/sysrq.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 
27 #define PORT_LTQ_ASC		111
28 #define MAXPORTS		2
29 #define UART_DUMMY_UER_RX	1
30 #define DRVNAME			"lantiq,asc"
31 #ifdef __BIG_ENDIAN
32 #define LTQ_ASC_TBUF		(0x0020 + 3)
33 #define LTQ_ASC_RBUF		(0x0024 + 3)
34 #else
35 #define LTQ_ASC_TBUF		0x0020
36 #define LTQ_ASC_RBUF		0x0024
37 #endif
38 #define LTQ_ASC_FSTAT		0x0048
39 #define LTQ_ASC_WHBSTATE	0x0018
40 #define LTQ_ASC_STATE		0x0014
41 #define LTQ_ASC_IRNCR		0x00F8
42 #define LTQ_ASC_CLC		0x0000
43 #define LTQ_ASC_ID		0x0008
44 #define LTQ_ASC_PISEL		0x0004
45 #define LTQ_ASC_TXFCON		0x0044
46 #define LTQ_ASC_RXFCON		0x0040
47 #define LTQ_ASC_CON		0x0010
48 #define LTQ_ASC_BG		0x0050
49 #define LTQ_ASC_IRNREN		0x00F4
50 
51 #define ASC_IRNREN_TX		0x1
52 #define ASC_IRNREN_RX		0x2
53 #define ASC_IRNREN_ERR		0x4
54 #define ASC_IRNREN_TX_BUF	0x8
55 #define ASC_IRNCR_TIR		0x1
56 #define ASC_IRNCR_RIR		0x2
57 #define ASC_IRNCR_EIR		0x4
58 #define ASC_IRNCR_MASK		GENMASK(2, 0)
59 
60 #define ASCOPT_CSIZE		0x3
61 #define TXFIFO_FL		1
62 #define RXFIFO_FL		1
63 #define ASCCLC_DISS		0x2
64 #define ASCCLC_RMCMASK		0x0000FF00
65 #define ASCCLC_RMCOFFSET	8
66 #define ASCCON_M_8ASYNC		0x0
67 #define ASCCON_M_7ASYNC		0x2
68 #define ASCCON_ODD		0x00000020
69 #define ASCCON_STP		0x00000080
70 #define ASCCON_BRS		0x00000100
71 #define ASCCON_FDE		0x00000200
72 #define ASCCON_R		0x00008000
73 #define ASCCON_FEN		0x00020000
74 #define ASCCON_ROEN		0x00080000
75 #define ASCCON_TOEN		0x00100000
76 #define ASCSTATE_PE		0x00010000
77 #define ASCSTATE_FE		0x00020000
78 #define ASCSTATE_ROE		0x00080000
79 #define ASCSTATE_ANY		(ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
80 #define ASCWHBSTATE_CLRREN	0x00000001
81 #define ASCWHBSTATE_SETREN	0x00000002
82 #define ASCWHBSTATE_CLRPE	0x00000004
83 #define ASCWHBSTATE_CLRFE	0x00000008
84 #define ASCWHBSTATE_CLRROE	0x00000020
85 #define ASCTXFCON_TXFEN		0x0001
86 #define ASCTXFCON_TXFFLU	0x0002
87 #define ASCTXFCON_TXFITLMASK	0x3F00
88 #define ASCTXFCON_TXFITLOFF	8
89 #define ASCRXFCON_RXFEN		0x0001
90 #define ASCRXFCON_RXFFLU	0x0002
91 #define ASCRXFCON_RXFITLMASK	0x3F00
92 #define ASCRXFCON_RXFITLOFF	8
93 #define ASCFSTAT_RXFFLMASK	0x003F
94 #define ASCFSTAT_TXFFLMASK	0x3F00
95 #define ASCFSTAT_TXFREEMASK	0x3F000000
96 #define ASCFSTAT_TXFREEOFF	24
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 void
143 lqasc_start_tx(struct uart_port *port)
144 {
145 	unsigned long flags;
146 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
147 
148 	spin_lock_irqsave(&ltq_port->lock, flags);
149 	lqasc_tx_chars(port);
150 	spin_unlock_irqrestore(&ltq_port->lock, flags);
151 	return;
152 }
153 
154 static void
155 lqasc_stop_rx(struct uart_port *port)
156 {
157 	__raw_writel(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
158 }
159 
160 static int
161 lqasc_rx_chars(struct uart_port *port)
162 {
163 	struct tty_port *tport = &port->state->port;
164 	unsigned int ch = 0, rsr = 0, fifocnt;
165 
166 	fifocnt = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
167 		  ASCFSTAT_RXFFLMASK;
168 	while (fifocnt--) {
169 		u8 flag = TTY_NORMAL;
170 		ch = readb(port->membase + LTQ_ASC_RBUF);
171 		rsr = (__raw_readl(port->membase + LTQ_ASC_STATE)
172 			& ASCSTATE_ANY) | UART_DUMMY_UER_RX;
173 		tty_flip_buffer_push(tport);
174 		port->icount.rx++;
175 
176 		/*
177 		 * Note that the error handling code is
178 		 * out of the main execution path
179 		 */
180 		if (rsr & ASCSTATE_ANY) {
181 			if (rsr & ASCSTATE_PE) {
182 				port->icount.parity++;
183 				asc_update_bits(0, ASCWHBSTATE_CLRPE,
184 					port->membase + LTQ_ASC_WHBSTATE);
185 			} else if (rsr & ASCSTATE_FE) {
186 				port->icount.frame++;
187 				asc_update_bits(0, ASCWHBSTATE_CLRFE,
188 					port->membase + LTQ_ASC_WHBSTATE);
189 			}
190 			if (rsr & ASCSTATE_ROE) {
191 				port->icount.overrun++;
192 				asc_update_bits(0, ASCWHBSTATE_CLRROE,
193 					port->membase + LTQ_ASC_WHBSTATE);
194 			}
195 
196 			rsr &= port->read_status_mask;
197 
198 			if (rsr & ASCSTATE_PE)
199 				flag = TTY_PARITY;
200 			else if (rsr & ASCSTATE_FE)
201 				flag = TTY_FRAME;
202 		}
203 
204 		if ((rsr & port->ignore_status_mask) == 0)
205 			tty_insert_flip_char(tport, ch, flag);
206 
207 		if (rsr & ASCSTATE_ROE)
208 			/*
209 			 * Overrun is special, since it's reported
210 			 * immediately, and doesn't affect the current
211 			 * character
212 			 */
213 			tty_insert_flip_char(tport, 0, TTY_OVERRUN);
214 	}
215 
216 	if (ch != 0)
217 		tty_flip_buffer_push(tport);
218 
219 	return 0;
220 }
221 
222 static void
223 lqasc_tx_chars(struct uart_port *port)
224 {
225 	struct circ_buf *xmit = &port->state->xmit;
226 	if (uart_tx_stopped(port)) {
227 		lqasc_stop_tx(port);
228 		return;
229 	}
230 
231 	while (((__raw_readl(port->membase + LTQ_ASC_FSTAT) &
232 		ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF) != 0) {
233 		if (port->x_char) {
234 			writeb(port->x_char, port->membase + LTQ_ASC_TBUF);
235 			port->icount.tx++;
236 			port->x_char = 0;
237 			continue;
238 		}
239 
240 		if (uart_circ_empty(xmit))
241 			break;
242 
243 		writeb(port->state->xmit.buf[port->state->xmit.tail],
244 			port->membase + LTQ_ASC_TBUF);
245 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
246 		port->icount.tx++;
247 	}
248 
249 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
250 		uart_write_wakeup(port);
251 }
252 
253 static irqreturn_t
254 lqasc_tx_int(int irq, void *_port)
255 {
256 	unsigned long flags;
257 	struct uart_port *port = (struct uart_port *)_port;
258 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
259 
260 	spin_lock_irqsave(&ltq_port->lock, flags);
261 	__raw_writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
262 	spin_unlock_irqrestore(&ltq_port->lock, flags);
263 	lqasc_start_tx(port);
264 	return IRQ_HANDLED;
265 }
266 
267 static irqreturn_t
268 lqasc_err_int(int irq, void *_port)
269 {
270 	unsigned long flags;
271 	struct uart_port *port = (struct uart_port *)_port;
272 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
273 
274 	spin_lock_irqsave(&ltq_port->lock, flags);
275 	/* clear any pending interrupts */
276 	asc_update_bits(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
277 		ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
278 	spin_unlock_irqrestore(&ltq_port->lock, flags);
279 	return IRQ_HANDLED;
280 }
281 
282 static irqreturn_t
283 lqasc_rx_int(int irq, void *_port)
284 {
285 	unsigned long flags;
286 	struct uart_port *port = (struct uart_port *)_port;
287 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
288 
289 	spin_lock_irqsave(&ltq_port->lock, flags);
290 	__raw_writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
291 	lqasc_rx_chars(port);
292 	spin_unlock_irqrestore(&ltq_port->lock, flags);
293 	return IRQ_HANDLED;
294 }
295 
296 static irqreturn_t lqasc_irq(int irq, void *p)
297 {
298 	unsigned long flags;
299 	u32 stat;
300 	struct uart_port *port = p;
301 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
302 
303 	spin_lock_irqsave(&ltq_port->lock, flags);
304 	stat = readl(port->membase + LTQ_ASC_IRNCR);
305 	spin_unlock_irqrestore(&ltq_port->lock, flags);
306 	if (!(stat & ASC_IRNCR_MASK))
307 		return IRQ_NONE;
308 
309 	if (stat & ASC_IRNCR_TIR)
310 		lqasc_tx_int(irq, p);
311 
312 	if (stat & ASC_IRNCR_RIR)
313 		lqasc_rx_int(irq, p);
314 
315 	if (stat & ASC_IRNCR_EIR)
316 		lqasc_err_int(irq, p);
317 
318 	return IRQ_HANDLED;
319 }
320 
321 static unsigned int
322 lqasc_tx_empty(struct uart_port *port)
323 {
324 	int status;
325 	status = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
326 		 ASCFSTAT_TXFFLMASK;
327 	return status ? 0 : TIOCSER_TEMT;
328 }
329 
330 static unsigned int
331 lqasc_get_mctrl(struct uart_port *port)
332 {
333 	return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR;
334 }
335 
336 static void
337 lqasc_set_mctrl(struct uart_port *port, u_int mctrl)
338 {
339 }
340 
341 static void
342 lqasc_break_ctl(struct uart_port *port, int break_state)
343 {
344 }
345 
346 static int
347 lqasc_startup(struct uart_port *port)
348 {
349 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
350 	int retval;
351 	unsigned long flags;
352 
353 	if (!IS_ERR(ltq_port->clk))
354 		clk_prepare_enable(ltq_port->clk);
355 	port->uartclk = clk_get_rate(ltq_port->freqclk);
356 
357 	spin_lock_irqsave(&ltq_port->lock, flags);
358 	asc_update_bits(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
359 		port->membase + LTQ_ASC_CLC);
360 
361 	__raw_writel(0, port->membase + LTQ_ASC_PISEL);
362 	__raw_writel(
363 		((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
364 		ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
365 		port->membase + LTQ_ASC_TXFCON);
366 	__raw_writel(
367 		((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
368 		| ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
369 		port->membase + LTQ_ASC_RXFCON);
370 	/* make sure other settings are written to hardware before
371 	 * setting enable bits
372 	 */
373 	wmb();
374 	asc_update_bits(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
375 		ASCCON_ROEN, port->membase + LTQ_ASC_CON);
376 
377 	spin_unlock_irqrestore(&ltq_port->lock, flags);
378 
379 	retval = ltq_port->soc->request_irq(port);
380 	if (retval)
381 		return retval;
382 
383 	__raw_writel(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
384 		port->membase + LTQ_ASC_IRNREN);
385 	return retval;
386 }
387 
388 static void
389 lqasc_shutdown(struct uart_port *port)
390 {
391 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
392 	unsigned long flags;
393 
394 	ltq_port->soc->free_irq(port);
395 
396 	spin_lock_irqsave(&ltq_port->lock, flags);
397 	__raw_writel(0, port->membase + LTQ_ASC_CON);
398 	asc_update_bits(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
399 		port->membase + LTQ_ASC_RXFCON);
400 	asc_update_bits(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
401 		port->membase + LTQ_ASC_TXFCON);
402 	spin_unlock_irqrestore(&ltq_port->lock, flags);
403 	if (!IS_ERR(ltq_port->clk))
404 		clk_disable_unprepare(ltq_port->clk);
405 }
406 
407 static void
408 lqasc_set_termios(struct uart_port *port,
409 	struct ktermios *new, struct ktermios *old)
410 {
411 	unsigned int cflag;
412 	unsigned int iflag;
413 	unsigned int divisor;
414 	unsigned int baud;
415 	unsigned int con = 0;
416 	unsigned long flags;
417 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
418 
419 	cflag = new->c_cflag;
420 	iflag = new->c_iflag;
421 
422 	switch (cflag & CSIZE) {
423 	case CS7:
424 		con = ASCCON_M_7ASYNC;
425 		break;
426 
427 	case CS5:
428 	case CS6:
429 	default:
430 		new->c_cflag &= ~ CSIZE;
431 		new->c_cflag |= CS8;
432 		con = ASCCON_M_8ASYNC;
433 		break;
434 	}
435 
436 	cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
437 
438 	if (cflag & CSTOPB)
439 		con |= ASCCON_STP;
440 
441 	if (cflag & PARENB) {
442 		if (!(cflag & PARODD))
443 			con &= ~ASCCON_ODD;
444 		else
445 			con |= ASCCON_ODD;
446 	}
447 
448 	port->read_status_mask = ASCSTATE_ROE;
449 	if (iflag & INPCK)
450 		port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
451 
452 	port->ignore_status_mask = 0;
453 	if (iflag & IGNPAR)
454 		port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
455 
456 	if (iflag & IGNBRK) {
457 		/*
458 		 * If we're ignoring parity and break indicators,
459 		 * ignore overruns too (for real raw support).
460 		 */
461 		if (iflag & IGNPAR)
462 			port->ignore_status_mask |= ASCSTATE_ROE;
463 	}
464 
465 	if ((cflag & CREAD) == 0)
466 		port->ignore_status_mask |= UART_DUMMY_UER_RX;
467 
468 	/* set error signals  - framing, parity  and overrun, enable receiver */
469 	con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
470 
471 	spin_lock_irqsave(&ltq_port->lock, flags);
472 
473 	/* set up CON */
474 	asc_update_bits(0, con, port->membase + LTQ_ASC_CON);
475 
476 	/* Set baud rate - take a divider of 2 into account */
477 	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
478 	divisor = uart_get_divisor(port, baud);
479 	divisor = divisor / 2 - 1;
480 
481 	/* disable the baudrate generator */
482 	asc_update_bits(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
483 
484 	/* make sure the fractional divider is off */
485 	asc_update_bits(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
486 
487 	/* set up to use divisor of 2 */
488 	asc_update_bits(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
489 
490 	/* now we can write the new baudrate into the register */
491 	__raw_writel(divisor, port->membase + LTQ_ASC_BG);
492 
493 	/* turn the baudrate generator back on */
494 	asc_update_bits(0, ASCCON_R, port->membase + LTQ_ASC_CON);
495 
496 	/* enable rx */
497 	__raw_writel(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
498 
499 	spin_unlock_irqrestore(&ltq_port->lock, flags);
500 
501 	/* Don't rewrite B0 */
502 	if (tty_termios_baud_rate(new))
503 		tty_termios_encode_baud_rate(new, baud, baud);
504 
505 	uart_update_timeout(port, cflag, baud);
506 }
507 
508 static const char*
509 lqasc_type(struct uart_port *port)
510 {
511 	if (port->type == PORT_LTQ_ASC)
512 		return DRVNAME;
513 	else
514 		return NULL;
515 }
516 
517 static void
518 lqasc_release_port(struct uart_port *port)
519 {
520 	struct platform_device *pdev = to_platform_device(port->dev);
521 
522 	if (port->flags & UPF_IOREMAP) {
523 		devm_iounmap(&pdev->dev, port->membase);
524 		port->membase = NULL;
525 	}
526 }
527 
528 static int
529 lqasc_request_port(struct uart_port *port)
530 {
531 	struct platform_device *pdev = to_platform_device(port->dev);
532 	struct resource *res;
533 	int size;
534 
535 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
536 	if (!res) {
537 		dev_err(&pdev->dev, "cannot obtain I/O memory region");
538 		return -ENODEV;
539 	}
540 	size = resource_size(res);
541 
542 	res = devm_request_mem_region(&pdev->dev, res->start,
543 		size, dev_name(&pdev->dev));
544 	if (!res) {
545 		dev_err(&pdev->dev, "cannot request I/O memory region");
546 		return -EBUSY;
547 	}
548 
549 	if (port->flags & UPF_IOREMAP) {
550 		port->membase = devm_ioremap(&pdev->dev,
551 			port->mapbase, size);
552 		if (port->membase == NULL)
553 			return -ENOMEM;
554 	}
555 	return 0;
556 }
557 
558 static void
559 lqasc_config_port(struct uart_port *port, int flags)
560 {
561 	if (flags & UART_CONFIG_TYPE) {
562 		port->type = PORT_LTQ_ASC;
563 		lqasc_request_port(port);
564 	}
565 }
566 
567 static int
568 lqasc_verify_port(struct uart_port *port,
569 	struct serial_struct *ser)
570 {
571 	int ret = 0;
572 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC)
573 		ret = -EINVAL;
574 	if (ser->irq < 0 || ser->irq >= NR_IRQS)
575 		ret = -EINVAL;
576 	if (ser->baud_base < 9600)
577 		ret = -EINVAL;
578 	return ret;
579 }
580 
581 static const struct uart_ops lqasc_pops = {
582 	.tx_empty =	lqasc_tx_empty,
583 	.set_mctrl =	lqasc_set_mctrl,
584 	.get_mctrl =	lqasc_get_mctrl,
585 	.stop_tx =	lqasc_stop_tx,
586 	.start_tx =	lqasc_start_tx,
587 	.stop_rx =	lqasc_stop_rx,
588 	.break_ctl =	lqasc_break_ctl,
589 	.startup =	lqasc_startup,
590 	.shutdown =	lqasc_shutdown,
591 	.set_termios =	lqasc_set_termios,
592 	.type =		lqasc_type,
593 	.release_port =	lqasc_release_port,
594 	.request_port =	lqasc_request_port,
595 	.config_port =	lqasc_config_port,
596 	.verify_port =	lqasc_verify_port,
597 };
598 
599 #ifdef CONFIG_SERIAL_LANTIQ_CONSOLE
600 static void
601 lqasc_console_putchar(struct uart_port *port, int ch)
602 {
603 	int fifofree;
604 
605 	if (!port->membase)
606 		return;
607 
608 	do {
609 		fifofree = (__raw_readl(port->membase + LTQ_ASC_FSTAT)
610 			& ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF;
611 	} while (fifofree == 0);
612 	writeb(ch, port->membase + LTQ_ASC_TBUF);
613 }
614 
615 static void lqasc_serial_port_write(struct uart_port *port, const char *s,
616 				    u_int count)
617 {
618 	uart_console_write(port, s, count, lqasc_console_putchar);
619 }
620 
621 static void
622 lqasc_console_write(struct console *co, const char *s, u_int count)
623 {
624 	struct ltq_uart_port *ltq_port;
625 	unsigned long flags;
626 
627 	if (co->index >= MAXPORTS)
628 		return;
629 
630 	ltq_port = lqasc_port[co->index];
631 	if (!ltq_port)
632 		return;
633 
634 	spin_lock_irqsave(&ltq_port->lock, flags);
635 	lqasc_serial_port_write(&ltq_port->port, s, count);
636 	spin_unlock_irqrestore(&ltq_port->lock, flags);
637 }
638 
639 static int __init
640 lqasc_console_setup(struct console *co, char *options)
641 {
642 	struct ltq_uart_port *ltq_port;
643 	struct uart_port *port;
644 	int baud = 115200;
645 	int bits = 8;
646 	int parity = 'n';
647 	int flow = 'n';
648 
649 	if (co->index >= MAXPORTS)
650 		return -ENODEV;
651 
652 	ltq_port = lqasc_port[co->index];
653 	if (!ltq_port)
654 		return -ENODEV;
655 
656 	port = &ltq_port->port;
657 
658 	if (!IS_ERR(ltq_port->clk))
659 		clk_prepare_enable(ltq_port->clk);
660 
661 	port->uartclk = clk_get_rate(ltq_port->freqclk);
662 
663 	if (options)
664 		uart_parse_options(options, &baud, &parity, &bits, &flow);
665 	return uart_set_options(port, co, baud, parity, bits, flow);
666 }
667 
668 static struct console lqasc_console = {
669 	.name =		"ttyLTQ",
670 	.write =	lqasc_console_write,
671 	.device =	uart_console_device,
672 	.setup =	lqasc_console_setup,
673 	.flags =	CON_PRINTBUFFER,
674 	.index =	-1,
675 	.data =		&lqasc_reg,
676 };
677 
678 static int __init
679 lqasc_console_init(void)
680 {
681 	register_console(&lqasc_console);
682 	return 0;
683 }
684 console_initcall(lqasc_console_init);
685 
686 static void lqasc_serial_early_console_write(struct console *co,
687 					     const char *s,
688 					     u_int count)
689 {
690 	struct earlycon_device *dev = co->data;
691 
692 	lqasc_serial_port_write(&dev->port, s, count);
693 }
694 
695 static int __init
696 lqasc_serial_early_console_setup(struct earlycon_device *device,
697 				 const char *opt)
698 {
699 	if (!device->port.membase)
700 		return -ENODEV;
701 
702 	device->con->write = lqasc_serial_early_console_write;
703 	return 0;
704 }
705 OF_EARLYCON_DECLARE(lantiq, "lantiq,asc", lqasc_serial_early_console_setup);
706 OF_EARLYCON_DECLARE(lantiq, "intel,lgm-asc", lqasc_serial_early_console_setup);
707 
708 #define LANTIQ_SERIAL_CONSOLE	(&lqasc_console)
709 
710 #else
711 
712 #define LANTIQ_SERIAL_CONSOLE	NULL
713 
714 #endif /* CONFIG_SERIAL_LANTIQ_CONSOLE */
715 
716 static struct uart_driver lqasc_reg = {
717 	.owner =	THIS_MODULE,
718 	.driver_name =	DRVNAME,
719 	.dev_name =	"ttyLTQ",
720 	.major =	0,
721 	.minor =	0,
722 	.nr =		MAXPORTS,
723 	.cons =		LANTIQ_SERIAL_CONSOLE,
724 };
725 
726 static int fetch_irq_lantiq(struct device *dev, struct ltq_uart_port *ltq_port)
727 {
728 	struct uart_port *port = &ltq_port->port;
729 	struct platform_device *pdev = to_platform_device(dev);
730 	int irq;
731 
732 	irq = platform_get_irq(pdev, 0);
733 	if (irq < 0)
734 		return irq;
735 	ltq_port->tx_irq = irq;
736 	irq = platform_get_irq(pdev, 1);
737 	if (irq < 0)
738 		return irq;
739 	ltq_port->rx_irq = irq;
740 	irq = platform_get_irq(pdev, 2);
741 	if (irq < 0)
742 		return irq;
743 	ltq_port->err_irq = irq;
744 
745 	port->irq = ltq_port->tx_irq;
746 
747 	return 0;
748 }
749 
750 static int request_irq_lantiq(struct uart_port *port)
751 {
752 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
753 	int retval;
754 
755 	retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
756 			     0, "asc_tx", port);
757 	if (retval) {
758 		dev_err(port->dev, "failed to request asc_tx\n");
759 		return retval;
760 	}
761 
762 	retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
763 			     0, "asc_rx", port);
764 	if (retval) {
765 		dev_err(port->dev, "failed to request asc_rx\n");
766 		goto err1;
767 	}
768 
769 	retval = request_irq(ltq_port->err_irq, lqasc_err_int,
770 			     0, "asc_err", port);
771 	if (retval) {
772 		dev_err(port->dev, "failed to request asc_err\n");
773 		goto err2;
774 	}
775 	return 0;
776 
777 err2:
778 	free_irq(ltq_port->rx_irq, port);
779 err1:
780 	free_irq(ltq_port->tx_irq, port);
781 	return retval;
782 }
783 
784 static void free_irq_lantiq(struct uart_port *port)
785 {
786 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
787 
788 	free_irq(ltq_port->tx_irq, port);
789 	free_irq(ltq_port->rx_irq, port);
790 	free_irq(ltq_port->err_irq, port);
791 }
792 
793 static int fetch_irq_intel(struct device *dev, struct ltq_uart_port *ltq_port)
794 {
795 	struct uart_port *port = &ltq_port->port;
796 	int ret;
797 
798 	ret = platform_get_irq(to_platform_device(dev), 0);
799 	if (ret < 0) {
800 		dev_err(dev, "failed to fetch IRQ for serial port\n");
801 		return ret;
802 	}
803 	ltq_port->common_irq = ret;
804 	port->irq = ret;
805 
806 	return 0;
807 }
808 
809 static int request_irq_intel(struct uart_port *port)
810 {
811 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
812 	int retval;
813 
814 	retval = request_irq(ltq_port->common_irq, lqasc_irq, 0,
815 			     "asc_irq", port);
816 	if (retval)
817 		dev_err(port->dev, "failed to request asc_irq\n");
818 
819 	return retval;
820 }
821 
822 static void free_irq_intel(struct uart_port *port)
823 {
824 	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
825 
826 	free_irq(ltq_port->common_irq, port);
827 }
828 
829 static int lqasc_probe(struct platform_device *pdev)
830 {
831 	struct device_node *node = pdev->dev.of_node;
832 	struct ltq_uart_port *ltq_port;
833 	struct uart_port *port;
834 	struct resource *mmres;
835 	int line;
836 	int ret;
837 
838 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
839 	if (!mmres) {
840 		dev_err(&pdev->dev,
841 			"failed to get memory for serial port\n");
842 		return -ENODEV;
843 	}
844 
845 	ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
846 				GFP_KERNEL);
847 	if (!ltq_port)
848 		return -ENOMEM;
849 
850 	port = &ltq_port->port;
851 
852 	ltq_port->soc = of_device_get_match_data(&pdev->dev);
853 	ret = ltq_port->soc->fetch_irq(&pdev->dev, ltq_port);
854 	if (ret)
855 		return ret;
856 
857 	/* get serial id */
858 	line = of_alias_get_id(node, "serial");
859 	if (line < 0) {
860 		if (IS_ENABLED(CONFIG_LANTIQ)) {
861 			if (mmres->start == CPHYSADDR(LTQ_EARLY_ASC))
862 				line = 0;
863 			else
864 				line = 1;
865 		} else {
866 			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
867 				line);
868 			return line;
869 		}
870 	}
871 
872 	if (lqasc_port[line]) {
873 		dev_err(&pdev->dev, "port %d already allocated\n", line);
874 		return -EBUSY;
875 	}
876 
877 	port->iotype	= SERIAL_IO_MEM;
878 	port->flags	= UPF_BOOT_AUTOCONF | UPF_IOREMAP;
879 	port->ops	= &lqasc_pops;
880 	port->fifosize	= 16;
881 	port->type	= PORT_LTQ_ASC;
882 	port->line	= line;
883 	port->dev	= &pdev->dev;
884 	/* unused, just to be backward-compatible */
885 	port->mapbase	= mmres->start;
886 
887 	if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
888 		ltq_port->freqclk = clk_get_fpi();
889 	else
890 		ltq_port->freqclk = devm_clk_get(&pdev->dev, "freq");
891 
892 
893 	if (IS_ERR(ltq_port->freqclk)) {
894 		pr_err("failed to get fpi clk\n");
895 		return -ENOENT;
896 	}
897 
898 	/* not all asc ports have clock gates, lets ignore the return code */
899 	if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
900 		ltq_port->clk = clk_get(&pdev->dev, NULL);
901 	else
902 		ltq_port->clk = devm_clk_get(&pdev->dev, "asc");
903 
904 	spin_lock_init(&ltq_port->lock);
905 	lqasc_port[line] = ltq_port;
906 	platform_set_drvdata(pdev, ltq_port);
907 
908 	ret = uart_add_one_port(&lqasc_reg, port);
909 
910 	return ret;
911 }
912 
913 static int lqasc_remove(struct platform_device *pdev)
914 {
915 	struct uart_port *port = platform_get_drvdata(pdev);
916 
917 	return uart_remove_one_port(&lqasc_reg, port);
918 }
919 
920 static const struct ltq_soc_data soc_data_lantiq = {
921 	.fetch_irq = fetch_irq_lantiq,
922 	.request_irq = request_irq_lantiq,
923 	.free_irq = free_irq_lantiq,
924 };
925 
926 static const struct ltq_soc_data soc_data_intel = {
927 	.fetch_irq = fetch_irq_intel,
928 	.request_irq = request_irq_intel,
929 	.free_irq = free_irq_intel,
930 };
931 
932 static const struct of_device_id ltq_asc_match[] = {
933 	{ .compatible = "lantiq,asc", .data = &soc_data_lantiq },
934 	{ .compatible = "intel,lgm-asc", .data = &soc_data_intel },
935 	{},
936 };
937 MODULE_DEVICE_TABLE(of, ltq_asc_match);
938 
939 static struct platform_driver lqasc_driver = {
940 	.probe		= lqasc_probe,
941 	.remove		= lqasc_remove,
942 	.driver		= {
943 		.name	= DRVNAME,
944 		.of_match_table = ltq_asc_match,
945 	},
946 };
947 
948 static int __init
949 init_lqasc(void)
950 {
951 	int ret;
952 
953 	ret = uart_register_driver(&lqasc_reg);
954 	if (ret != 0)
955 		return ret;
956 
957 	ret = platform_driver_register(&lqasc_driver);
958 	if (ret != 0)
959 		uart_unregister_driver(&lqasc_reg);
960 
961 	return ret;
962 }
963 
964 static void __exit exit_lqasc(void)
965 {
966 	platform_driver_unregister(&lqasc_driver);
967 	uart_unregister_driver(&lqasc_reg);
968 }
969 
970 module_init(init_lqasc);
971 module_exit(exit_lqasc);
972 
973 MODULE_DESCRIPTION("Serial driver for Lantiq & Intel gateway SoCs");
974 MODULE_LICENSE("GPL v2");
975