xref: /openbmc/linux/drivers/tty/serial/pxa.c (revision 8fdff1dc)
1 /*
2  *  Based on drivers/serial/8250.c by Russell King.
3  *
4  *  Author:	Nicolas Pitre
5  *  Created:	Feb 20, 2003
6  *  Copyright:	(C) 2003 Monta Vista Software, Inc.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * Note 1: This driver is made separate from the already too overloaded
14  * 8250.c because it needs some kirks of its own and that'll make it
15  * easier to add DMA support.
16  *
17  * Note 2: I'm too sick of device allocation policies for serial ports.
18  * If someone else wants to request an "official" allocation of major/minor
19  * for this driver please be my guest.  And don't forget that new hardware
20  * to come from Intel might have more than 3 or 4 of those UARTs.  Let's
21  * hope for a better port registration and dynamic device allocation scheme
22  * with the serial core maintainer satisfaction to appear soon.
23  */
24 
25 
26 #if defined(CONFIG_SERIAL_PXA_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
27 #define SUPPORT_SYSRQ
28 #endif
29 
30 #include <linux/module.h>
31 #include <linux/ioport.h>
32 #include <linux/init.h>
33 #include <linux/console.h>
34 #include <linux/sysrq.h>
35 #include <linux/serial_reg.h>
36 #include <linux/circ_buf.h>
37 #include <linux/delay.h>
38 #include <linux/interrupt.h>
39 #include <linux/of.h>
40 #include <linux/platform_device.h>
41 #include <linux/tty.h>
42 #include <linux/tty_flip.h>
43 #include <linux/serial_core.h>
44 #include <linux/clk.h>
45 #include <linux/io.h>
46 #include <linux/slab.h>
47 
48 #define PXA_NAME_LEN		8
49 
50 struct uart_pxa_port {
51 	struct uart_port        port;
52 	unsigned char           ier;
53 	unsigned char           lcr;
54 	unsigned char           mcr;
55 	unsigned int            lsr_break_flag;
56 	struct clk		*clk;
57 	char			name[PXA_NAME_LEN];
58 };
59 
60 static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
61 {
62 	offset <<= 2;
63 	return readl(up->port.membase + offset);
64 }
65 
66 static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
67 {
68 	offset <<= 2;
69 	writel(value, up->port.membase + offset);
70 }
71 
72 static void serial_pxa_enable_ms(struct uart_port *port)
73 {
74 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
75 
76 	up->ier |= UART_IER_MSI;
77 	serial_out(up, UART_IER, up->ier);
78 }
79 
80 static void serial_pxa_stop_tx(struct uart_port *port)
81 {
82 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
83 
84 	if (up->ier & UART_IER_THRI) {
85 		up->ier &= ~UART_IER_THRI;
86 		serial_out(up, UART_IER, up->ier);
87 	}
88 }
89 
90 static void serial_pxa_stop_rx(struct uart_port *port)
91 {
92 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
93 
94 	up->ier &= ~UART_IER_RLSI;
95 	up->port.read_status_mask &= ~UART_LSR_DR;
96 	serial_out(up, UART_IER, up->ier);
97 }
98 
99 static inline void receive_chars(struct uart_pxa_port *up, int *status)
100 {
101 	struct tty_struct *tty = up->port.state->port.tty;
102 	unsigned int ch, flag;
103 	int max_count = 256;
104 
105 	do {
106 		/* work around Errata #20 according to
107 		 * Intel(R) PXA27x Processor Family
108 		 * Specification Update (May 2005)
109 		 *
110 		 * Step 2
111 		 * Disable the Reciever Time Out Interrupt via IER[RTOEI]
112 		 */
113 		up->ier &= ~UART_IER_RTOIE;
114 		serial_out(up, UART_IER, up->ier);
115 
116 		ch = serial_in(up, UART_RX);
117 		flag = TTY_NORMAL;
118 		up->port.icount.rx++;
119 
120 		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
121 				       UART_LSR_FE | UART_LSR_OE))) {
122 			/*
123 			 * For statistics only
124 			 */
125 			if (*status & UART_LSR_BI) {
126 				*status &= ~(UART_LSR_FE | UART_LSR_PE);
127 				up->port.icount.brk++;
128 				/*
129 				 * We do the SysRQ and SAK checking
130 				 * here because otherwise the break
131 				 * may get masked by ignore_status_mask
132 				 * or read_status_mask.
133 				 */
134 				if (uart_handle_break(&up->port))
135 					goto ignore_char;
136 			} else if (*status & UART_LSR_PE)
137 				up->port.icount.parity++;
138 			else if (*status & UART_LSR_FE)
139 				up->port.icount.frame++;
140 			if (*status & UART_LSR_OE)
141 				up->port.icount.overrun++;
142 
143 			/*
144 			 * Mask off conditions which should be ignored.
145 			 */
146 			*status &= up->port.read_status_mask;
147 
148 #ifdef CONFIG_SERIAL_PXA_CONSOLE
149 			if (up->port.line == up->port.cons->index) {
150 				/* Recover the break flag from console xmit */
151 				*status |= up->lsr_break_flag;
152 				up->lsr_break_flag = 0;
153 			}
154 #endif
155 			if (*status & UART_LSR_BI) {
156 				flag = TTY_BREAK;
157 			} else if (*status & UART_LSR_PE)
158 				flag = TTY_PARITY;
159 			else if (*status & UART_LSR_FE)
160 				flag = TTY_FRAME;
161 		}
162 
163 		if (uart_handle_sysrq_char(&up->port, ch))
164 			goto ignore_char;
165 
166 		uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
167 
168 	ignore_char:
169 		*status = serial_in(up, UART_LSR);
170 	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
171 	tty_flip_buffer_push(tty);
172 
173 	/* work around Errata #20 according to
174 	 * Intel(R) PXA27x Processor Family
175 	 * Specification Update (May 2005)
176 	 *
177 	 * Step 6:
178 	 * No more data in FIFO: Re-enable RTO interrupt via IER[RTOIE]
179 	 */
180 	up->ier |= UART_IER_RTOIE;
181 	serial_out(up, UART_IER, up->ier);
182 }
183 
184 static void transmit_chars(struct uart_pxa_port *up)
185 {
186 	struct circ_buf *xmit = &up->port.state->xmit;
187 	int count;
188 
189 	if (up->port.x_char) {
190 		serial_out(up, UART_TX, up->port.x_char);
191 		up->port.icount.tx++;
192 		up->port.x_char = 0;
193 		return;
194 	}
195 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
196 		serial_pxa_stop_tx(&up->port);
197 		return;
198 	}
199 
200 	count = up->port.fifosize / 2;
201 	do {
202 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
203 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
204 		up->port.icount.tx++;
205 		if (uart_circ_empty(xmit))
206 			break;
207 	} while (--count > 0);
208 
209 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
210 		uart_write_wakeup(&up->port);
211 
212 
213 	if (uart_circ_empty(xmit))
214 		serial_pxa_stop_tx(&up->port);
215 }
216 
217 static void serial_pxa_start_tx(struct uart_port *port)
218 {
219 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
220 
221 	if (!(up->ier & UART_IER_THRI)) {
222 		up->ier |= UART_IER_THRI;
223 		serial_out(up, UART_IER, up->ier);
224 	}
225 }
226 
227 static inline void check_modem_status(struct uart_pxa_port *up)
228 {
229 	int status;
230 
231 	status = serial_in(up, UART_MSR);
232 
233 	if ((status & UART_MSR_ANY_DELTA) == 0)
234 		return;
235 
236 	if (status & UART_MSR_TERI)
237 		up->port.icount.rng++;
238 	if (status & UART_MSR_DDSR)
239 		up->port.icount.dsr++;
240 	if (status & UART_MSR_DDCD)
241 		uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
242 	if (status & UART_MSR_DCTS)
243 		uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
244 
245 	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
246 }
247 
248 /*
249  * This handles the interrupt from one port.
250  */
251 static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
252 {
253 	struct uart_pxa_port *up = dev_id;
254 	unsigned int iir, lsr;
255 
256 	iir = serial_in(up, UART_IIR);
257 	if (iir & UART_IIR_NO_INT)
258 		return IRQ_NONE;
259 	lsr = serial_in(up, UART_LSR);
260 	if (lsr & UART_LSR_DR)
261 		receive_chars(up, &lsr);
262 	check_modem_status(up);
263 	if (lsr & UART_LSR_THRE)
264 		transmit_chars(up);
265 	return IRQ_HANDLED;
266 }
267 
268 static unsigned int serial_pxa_tx_empty(struct uart_port *port)
269 {
270 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
271 	unsigned long flags;
272 	unsigned int ret;
273 
274 	spin_lock_irqsave(&up->port.lock, flags);
275 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
276 	spin_unlock_irqrestore(&up->port.lock, flags);
277 
278 	return ret;
279 }
280 
281 static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
282 {
283 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
284 	unsigned char status;
285 	unsigned int ret;
286 
287 	status = serial_in(up, UART_MSR);
288 
289 	ret = 0;
290 	if (status & UART_MSR_DCD)
291 		ret |= TIOCM_CAR;
292 	if (status & UART_MSR_RI)
293 		ret |= TIOCM_RNG;
294 	if (status & UART_MSR_DSR)
295 		ret |= TIOCM_DSR;
296 	if (status & UART_MSR_CTS)
297 		ret |= TIOCM_CTS;
298 	return ret;
299 }
300 
301 static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
302 {
303 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
304 	unsigned char mcr = 0;
305 
306 	if (mctrl & TIOCM_RTS)
307 		mcr |= UART_MCR_RTS;
308 	if (mctrl & TIOCM_DTR)
309 		mcr |= UART_MCR_DTR;
310 	if (mctrl & TIOCM_OUT1)
311 		mcr |= UART_MCR_OUT1;
312 	if (mctrl & TIOCM_OUT2)
313 		mcr |= UART_MCR_OUT2;
314 	if (mctrl & TIOCM_LOOP)
315 		mcr |= UART_MCR_LOOP;
316 
317 	mcr |= up->mcr;
318 
319 	serial_out(up, UART_MCR, mcr);
320 }
321 
322 static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
323 {
324 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
325 	unsigned long flags;
326 
327 	spin_lock_irqsave(&up->port.lock, flags);
328 	if (break_state == -1)
329 		up->lcr |= UART_LCR_SBC;
330 	else
331 		up->lcr &= ~UART_LCR_SBC;
332 	serial_out(up, UART_LCR, up->lcr);
333 	spin_unlock_irqrestore(&up->port.lock, flags);
334 }
335 
336 #if 0
337 static void serial_pxa_dma_init(struct pxa_uart *up)
338 {
339 	up->rxdma =
340 		pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_receive_dma, up);
341 	if (up->rxdma < 0)
342 		goto out;
343 	up->txdma =
344 		pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_transmit_dma, up);
345 	if (up->txdma < 0)
346 		goto err_txdma;
347 	up->dmadesc = kmalloc(4 * sizeof(pxa_dma_desc), GFP_KERNEL);
348 	if (!up->dmadesc)
349 		goto err_alloc;
350 
351 	/* ... */
352 err_alloc:
353 	pxa_free_dma(up->txdma);
354 err_rxdma:
355 	pxa_free_dma(up->rxdma);
356 out:
357 	return;
358 }
359 #endif
360 
361 static int serial_pxa_startup(struct uart_port *port)
362 {
363 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
364 	unsigned long flags;
365 	int retval;
366 
367 	if (port->line == 3) /* HWUART */
368 		up->mcr |= UART_MCR_AFE;
369 	else
370 		up->mcr = 0;
371 
372 	up->port.uartclk = clk_get_rate(up->clk);
373 
374 	/*
375 	 * Allocate the IRQ
376 	 */
377 	retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
378 	if (retval)
379 		return retval;
380 
381 	/*
382 	 * Clear the FIFO buffers and disable them.
383 	 * (they will be reenabled in set_termios())
384 	 */
385 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
386 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
387 			UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
388 	serial_out(up, UART_FCR, 0);
389 
390 	/*
391 	 * Clear the interrupt registers.
392 	 */
393 	(void) serial_in(up, UART_LSR);
394 	(void) serial_in(up, UART_RX);
395 	(void) serial_in(up, UART_IIR);
396 	(void) serial_in(up, UART_MSR);
397 
398 	/*
399 	 * Now, initialize the UART
400 	 */
401 	serial_out(up, UART_LCR, UART_LCR_WLEN8);
402 
403 	spin_lock_irqsave(&up->port.lock, flags);
404 	up->port.mctrl |= TIOCM_OUT2;
405 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
406 	spin_unlock_irqrestore(&up->port.lock, flags);
407 
408 	/*
409 	 * Finally, enable interrupts.  Note: Modem status interrupts
410 	 * are set via set_termios(), which will be occurring imminently
411 	 * anyway, so we don't enable them here.
412 	 */
413 	up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
414 	serial_out(up, UART_IER, up->ier);
415 
416 	/*
417 	 * And clear the interrupt registers again for luck.
418 	 */
419 	(void) serial_in(up, UART_LSR);
420 	(void) serial_in(up, UART_RX);
421 	(void) serial_in(up, UART_IIR);
422 	(void) serial_in(up, UART_MSR);
423 
424 	return 0;
425 }
426 
427 static void serial_pxa_shutdown(struct uart_port *port)
428 {
429 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
430 	unsigned long flags;
431 
432 	free_irq(up->port.irq, up);
433 
434 	/*
435 	 * Disable interrupts from this port
436 	 */
437 	up->ier = 0;
438 	serial_out(up, UART_IER, 0);
439 
440 	spin_lock_irqsave(&up->port.lock, flags);
441 	up->port.mctrl &= ~TIOCM_OUT2;
442 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
443 	spin_unlock_irqrestore(&up->port.lock, flags);
444 
445 	/*
446 	 * Disable break condition and FIFOs
447 	 */
448 	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
449 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
450 				  UART_FCR_CLEAR_RCVR |
451 				  UART_FCR_CLEAR_XMIT);
452 	serial_out(up, UART_FCR, 0);
453 }
454 
455 static void
456 serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
457 		       struct ktermios *old)
458 {
459 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
460 	unsigned char cval, fcr = 0;
461 	unsigned long flags;
462 	unsigned int baud, quot;
463 	unsigned int dll;
464 
465 	switch (termios->c_cflag & CSIZE) {
466 	case CS5:
467 		cval = UART_LCR_WLEN5;
468 		break;
469 	case CS6:
470 		cval = UART_LCR_WLEN6;
471 		break;
472 	case CS7:
473 		cval = UART_LCR_WLEN7;
474 		break;
475 	default:
476 	case CS8:
477 		cval = UART_LCR_WLEN8;
478 		break;
479 	}
480 
481 	if (termios->c_cflag & CSTOPB)
482 		cval |= UART_LCR_STOP;
483 	if (termios->c_cflag & PARENB)
484 		cval |= UART_LCR_PARITY;
485 	if (!(termios->c_cflag & PARODD))
486 		cval |= UART_LCR_EPAR;
487 
488 	/*
489 	 * Ask the core to calculate the divisor for us.
490 	 */
491 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
492 	quot = uart_get_divisor(port, baud);
493 
494 	if ((up->port.uartclk / quot) < (2400 * 16))
495 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
496 	else if ((up->port.uartclk / quot) < (230400 * 16))
497 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
498 	else
499 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
500 
501 	/*
502 	 * Ok, we're now changing the port state.  Do it with
503 	 * interrupts disabled.
504 	 */
505 	spin_lock_irqsave(&up->port.lock, flags);
506 
507 	/*
508 	 * Ensure the port will be enabled.
509 	 * This is required especially for serial console.
510 	 */
511 	up->ier |= UART_IER_UUE;
512 
513 	/*
514 	 * Update the per-port timeout.
515 	 */
516 	uart_update_timeout(port, termios->c_cflag, baud);
517 
518 	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
519 	if (termios->c_iflag & INPCK)
520 		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
521 	if (termios->c_iflag & (BRKINT | PARMRK))
522 		up->port.read_status_mask |= UART_LSR_BI;
523 
524 	/*
525 	 * Characters to ignore
526 	 */
527 	up->port.ignore_status_mask = 0;
528 	if (termios->c_iflag & IGNPAR)
529 		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
530 	if (termios->c_iflag & IGNBRK) {
531 		up->port.ignore_status_mask |= UART_LSR_BI;
532 		/*
533 		 * If we're ignoring parity and break indicators,
534 		 * ignore overruns too (for real raw support).
535 		 */
536 		if (termios->c_iflag & IGNPAR)
537 			up->port.ignore_status_mask |= UART_LSR_OE;
538 	}
539 
540 	/*
541 	 * ignore all characters if CREAD is not set
542 	 */
543 	if ((termios->c_cflag & CREAD) == 0)
544 		up->port.ignore_status_mask |= UART_LSR_DR;
545 
546 	/*
547 	 * CTS flow control flag and modem status interrupts
548 	 */
549 	up->ier &= ~UART_IER_MSI;
550 	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
551 		up->ier |= UART_IER_MSI;
552 
553 	serial_out(up, UART_IER, up->ier);
554 
555 	if (termios->c_cflag & CRTSCTS)
556 		up->mcr |= UART_MCR_AFE;
557 	else
558 		up->mcr &= ~UART_MCR_AFE;
559 
560 	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);	/* set DLAB */
561 	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
562 
563 	/*
564 	 * work around Errata #75 according to Intel(R) PXA27x Processor Family
565 	 * Specification Update (Nov 2005)
566 	 */
567 	dll = serial_in(up, UART_DLL);
568 	WARN_ON(dll != (quot & 0xff));
569 
570 	serial_out(up, UART_DLM, quot >> 8);		/* MS of divisor */
571 	serial_out(up, UART_LCR, cval);			/* reset DLAB */
572 	up->lcr = cval;					/* Save LCR */
573 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
574 	serial_out(up, UART_FCR, fcr);
575 	spin_unlock_irqrestore(&up->port.lock, flags);
576 }
577 
578 static void
579 serial_pxa_pm(struct uart_port *port, unsigned int state,
580 	      unsigned int oldstate)
581 {
582 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
583 
584 	if (!state)
585 		clk_prepare_enable(up->clk);
586 	else
587 		clk_disable_unprepare(up->clk);
588 }
589 
590 static void serial_pxa_release_port(struct uart_port *port)
591 {
592 }
593 
594 static int serial_pxa_request_port(struct uart_port *port)
595 {
596 	return 0;
597 }
598 
599 static void serial_pxa_config_port(struct uart_port *port, int flags)
600 {
601 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
602 	up->port.type = PORT_PXA;
603 }
604 
605 static int
606 serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
607 {
608 	/* we don't want the core code to modify any port params */
609 	return -EINVAL;
610 }
611 
612 static const char *
613 serial_pxa_type(struct uart_port *port)
614 {
615 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
616 	return up->name;
617 }
618 
619 static struct uart_pxa_port *serial_pxa_ports[4];
620 static struct uart_driver serial_pxa_reg;
621 
622 #ifdef CONFIG_SERIAL_PXA_CONSOLE
623 
624 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
625 
626 /*
627  *	Wait for transmitter & holding register to empty
628  */
629 static inline void wait_for_xmitr(struct uart_pxa_port *up)
630 {
631 	unsigned int status, tmout = 10000;
632 
633 	/* Wait up to 10ms for the character(s) to be sent. */
634 	do {
635 		status = serial_in(up, UART_LSR);
636 
637 		if (status & UART_LSR_BI)
638 			up->lsr_break_flag = UART_LSR_BI;
639 
640 		if (--tmout == 0)
641 			break;
642 		udelay(1);
643 	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
644 
645 	/* Wait up to 1s for flow control if necessary */
646 	if (up->port.flags & UPF_CONS_FLOW) {
647 		tmout = 1000000;
648 		while (--tmout &&
649 		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
650 			udelay(1);
651 	}
652 }
653 
654 static void serial_pxa_console_putchar(struct uart_port *port, int ch)
655 {
656 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
657 
658 	wait_for_xmitr(up);
659 	serial_out(up, UART_TX, ch);
660 }
661 
662 /*
663  * Print a string to the serial port trying not to disturb
664  * any possible real use of the port...
665  *
666  *	The console_lock must be held when we get here.
667  */
668 static void
669 serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
670 {
671 	struct uart_pxa_port *up = serial_pxa_ports[co->index];
672 	unsigned int ier;
673 	unsigned long flags;
674 	int locked = 1;
675 
676 	clk_prepare_enable(up->clk);
677 
678 	local_irq_save(flags);
679 	if (up->port.sysrq)
680 		locked = 0;
681 	else if (oops_in_progress)
682 		locked = spin_trylock(&up->port.lock);
683 	else
684 		spin_lock(&up->port.lock);
685 
686 	/*
687 	 *	First save the IER then disable the interrupts
688 	 */
689 	ier = serial_in(up, UART_IER);
690 	serial_out(up, UART_IER, UART_IER_UUE);
691 
692 	uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
693 
694 	/*
695 	 *	Finally, wait for transmitter to become empty
696 	 *	and restore the IER
697 	 */
698 	wait_for_xmitr(up);
699 	serial_out(up, UART_IER, ier);
700 
701 	if (locked)
702 		spin_unlock(&up->port.lock);
703 	local_irq_restore(flags);
704 
705 	clk_disable_unprepare(up->clk);
706 }
707 
708 #ifdef CONFIG_CONSOLE_POLL
709 /*
710  * Console polling routines for writing and reading from the uart while
711  * in an interrupt or debug context.
712  */
713 
714 static int serial_pxa_get_poll_char(struct uart_port *port)
715 {
716 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
717 	unsigned char lsr = serial_in(up, UART_LSR);
718 
719 	while (!(lsr & UART_LSR_DR))
720 		lsr = serial_in(up, UART_LSR);
721 
722 	return serial_in(up, UART_RX);
723 }
724 
725 
726 static void serial_pxa_put_poll_char(struct uart_port *port,
727 			 unsigned char c)
728 {
729 	unsigned int ier;
730 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
731 
732 	/*
733 	 *	First save the IER then disable the interrupts
734 	 */
735 	ier = serial_in(up, UART_IER);
736 	serial_out(up, UART_IER, UART_IER_UUE);
737 
738 	wait_for_xmitr(up);
739 	/*
740 	 *	Send the character out.
741 	 *	If a LF, also do CR...
742 	 */
743 	serial_out(up, UART_TX, c);
744 	if (c == 10) {
745 		wait_for_xmitr(up);
746 		serial_out(up, UART_TX, 13);
747 	}
748 
749 	/*
750 	 *	Finally, wait for transmitter to become empty
751 	 *	and restore the IER
752 	 */
753 	wait_for_xmitr(up);
754 	serial_out(up, UART_IER, ier);
755 }
756 
757 #endif /* CONFIG_CONSOLE_POLL */
758 
759 static int __init
760 serial_pxa_console_setup(struct console *co, char *options)
761 {
762 	struct uart_pxa_port *up;
763 	int baud = 9600;
764 	int bits = 8;
765 	int parity = 'n';
766 	int flow = 'n';
767 
768 	if (co->index == -1 || co->index >= serial_pxa_reg.nr)
769 		co->index = 0;
770 	up = serial_pxa_ports[co->index];
771 	if (!up)
772 		return -ENODEV;
773 
774 	if (options)
775 		uart_parse_options(options, &baud, &parity, &bits, &flow);
776 
777 	return uart_set_options(&up->port, co, baud, parity, bits, flow);
778 }
779 
780 static struct console serial_pxa_console = {
781 	.name		= "ttyS",
782 	.write		= serial_pxa_console_write,
783 	.device		= uart_console_device,
784 	.setup		= serial_pxa_console_setup,
785 	.flags		= CON_PRINTBUFFER,
786 	.index		= -1,
787 	.data		= &serial_pxa_reg,
788 };
789 
790 #define PXA_CONSOLE	&serial_pxa_console
791 #else
792 #define PXA_CONSOLE	NULL
793 #endif
794 
795 struct uart_ops serial_pxa_pops = {
796 	.tx_empty	= serial_pxa_tx_empty,
797 	.set_mctrl	= serial_pxa_set_mctrl,
798 	.get_mctrl	= serial_pxa_get_mctrl,
799 	.stop_tx	= serial_pxa_stop_tx,
800 	.start_tx	= serial_pxa_start_tx,
801 	.stop_rx	= serial_pxa_stop_rx,
802 	.enable_ms	= serial_pxa_enable_ms,
803 	.break_ctl	= serial_pxa_break_ctl,
804 	.startup	= serial_pxa_startup,
805 	.shutdown	= serial_pxa_shutdown,
806 	.set_termios	= serial_pxa_set_termios,
807 	.pm		= serial_pxa_pm,
808 	.type		= serial_pxa_type,
809 	.release_port	= serial_pxa_release_port,
810 	.request_port	= serial_pxa_request_port,
811 	.config_port	= serial_pxa_config_port,
812 	.verify_port	= serial_pxa_verify_port,
813 #ifdef CONFIG_CONSOLE_POLL
814 	.poll_get_char = serial_pxa_get_poll_char,
815 	.poll_put_char = serial_pxa_put_poll_char,
816 #endif
817 };
818 
819 static struct uart_driver serial_pxa_reg = {
820 	.owner		= THIS_MODULE,
821 	.driver_name	= "PXA serial",
822 	.dev_name	= "ttyS",
823 	.major		= TTY_MAJOR,
824 	.minor		= 64,
825 	.nr		= 4,
826 	.cons		= PXA_CONSOLE,
827 };
828 
829 #ifdef CONFIG_PM
830 static int serial_pxa_suspend(struct device *dev)
831 {
832         struct uart_pxa_port *sport = dev_get_drvdata(dev);
833 
834         if (sport)
835                 uart_suspend_port(&serial_pxa_reg, &sport->port);
836 
837         return 0;
838 }
839 
840 static int serial_pxa_resume(struct device *dev)
841 {
842         struct uart_pxa_port *sport = dev_get_drvdata(dev);
843 
844         if (sport)
845                 uart_resume_port(&serial_pxa_reg, &sport->port);
846 
847         return 0;
848 }
849 
850 static const struct dev_pm_ops serial_pxa_pm_ops = {
851 	.suspend	= serial_pxa_suspend,
852 	.resume		= serial_pxa_resume,
853 };
854 #endif
855 
856 static struct of_device_id serial_pxa_dt_ids[] = {
857 	{ .compatible = "mrvl,pxa-uart", },
858 	{ .compatible = "mrvl,mmp-uart", },
859 	{}
860 };
861 MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
862 
863 static int serial_pxa_probe_dt(struct platform_device *pdev,
864 			       struct uart_pxa_port *sport)
865 {
866 	struct device_node *np = pdev->dev.of_node;
867 	int ret;
868 
869 	if (!np)
870 		return 1;
871 
872 	ret = of_alias_get_id(np, "serial");
873 	if (ret < 0) {
874 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
875 		return ret;
876 	}
877 	sport->port.line = ret;
878 	return 0;
879 }
880 
881 static int serial_pxa_probe(struct platform_device *dev)
882 {
883 	struct uart_pxa_port *sport;
884 	struct resource *mmres, *irqres;
885 	int ret;
886 
887 	mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
888 	irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
889 	if (!mmres || !irqres)
890 		return -ENODEV;
891 
892 	sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
893 	if (!sport)
894 		return -ENOMEM;
895 
896 	sport->clk = clk_get(&dev->dev, NULL);
897 	if (IS_ERR(sport->clk)) {
898 		ret = PTR_ERR(sport->clk);
899 		goto err_free;
900 	}
901 
902 	sport->port.type = PORT_PXA;
903 	sport->port.iotype = UPIO_MEM;
904 	sport->port.mapbase = mmres->start;
905 	sport->port.irq = irqres->start;
906 	sport->port.fifosize = 64;
907 	sport->port.ops = &serial_pxa_pops;
908 	sport->port.dev = &dev->dev;
909 	sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
910 	sport->port.uartclk = clk_get_rate(sport->clk);
911 
912 	ret = serial_pxa_probe_dt(dev, sport);
913 	if (ret > 0)
914 		sport->port.line = dev->id;
915 	else if (ret < 0)
916 		goto err_clk;
917 	snprintf(sport->name, PXA_NAME_LEN - 1, "UART%d", sport->port.line + 1);
918 
919 	sport->port.membase = ioremap(mmres->start, resource_size(mmres));
920 	if (!sport->port.membase) {
921 		ret = -ENOMEM;
922 		goto err_clk;
923 	}
924 
925 	serial_pxa_ports[sport->port.line] = sport;
926 
927 	uart_add_one_port(&serial_pxa_reg, &sport->port);
928 	platform_set_drvdata(dev, sport);
929 
930 	return 0;
931 
932  err_clk:
933 	clk_put(sport->clk);
934  err_free:
935 	kfree(sport);
936 	return ret;
937 }
938 
939 static int serial_pxa_remove(struct platform_device *dev)
940 {
941 	struct uart_pxa_port *sport = platform_get_drvdata(dev);
942 
943 	platform_set_drvdata(dev, NULL);
944 
945 	uart_remove_one_port(&serial_pxa_reg, &sport->port);
946 	clk_put(sport->clk);
947 	kfree(sport);
948 
949 	return 0;
950 }
951 
952 static struct platform_driver serial_pxa_driver = {
953         .probe          = serial_pxa_probe,
954         .remove         = serial_pxa_remove,
955 
956 	.driver		= {
957 	        .name	= "pxa2xx-uart",
958 		.owner	= THIS_MODULE,
959 #ifdef CONFIG_PM
960 		.pm	= &serial_pxa_pm_ops,
961 #endif
962 		.of_match_table = serial_pxa_dt_ids,
963 	},
964 };
965 
966 int __init serial_pxa_init(void)
967 {
968 	int ret;
969 
970 	ret = uart_register_driver(&serial_pxa_reg);
971 	if (ret != 0)
972 		return ret;
973 
974 	ret = platform_driver_register(&serial_pxa_driver);
975 	if (ret != 0)
976 		uart_unregister_driver(&serial_pxa_reg);
977 
978 	return ret;
979 }
980 
981 void __exit serial_pxa_exit(void)
982 {
983 	platform_driver_unregister(&serial_pxa_driver);
984 	uart_unregister_driver(&serial_pxa_reg);
985 }
986 
987 module_init(serial_pxa_init);
988 module_exit(serial_pxa_exit);
989 
990 MODULE_LICENSE("GPL");
991 MODULE_ALIAS("platform:pxa2xx-uart");
992