xref: /openbmc/linux/drivers/tty/serial/pxa.c (revision aac5987a)
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/ioport.h>
31 #include <linux/init.h>
32 #include <linux/console.h>
33 #include <linux/sysrq.h>
34 #include <linux/serial_reg.h>
35 #include <linux/circ_buf.h>
36 #include <linux/delay.h>
37 #include <linux/interrupt.h>
38 #include <linux/of.h>
39 #include <linux/platform_device.h>
40 #include <linux/tty.h>
41 #include <linux/tty_flip.h>
42 #include <linux/serial_core.h>
43 #include <linux/clk.h>
44 #include <linux/io.h>
45 #include <linux/slab.h>
46 
47 #define PXA_NAME_LEN		8
48 
49 struct uart_pxa_port {
50 	struct uart_port        port;
51 	unsigned char           ier;
52 	unsigned char           lcr;
53 	unsigned char           mcr;
54 	unsigned int            lsr_break_flag;
55 	struct clk		*clk;
56 	char			name[PXA_NAME_LEN];
57 };
58 
59 static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
60 {
61 	offset <<= 2;
62 	return readl(up->port.membase + offset);
63 }
64 
65 static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
66 {
67 	offset <<= 2;
68 	writel(value, up->port.membase + offset);
69 }
70 
71 static void serial_pxa_enable_ms(struct uart_port *port)
72 {
73 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
74 
75 	up->ier |= UART_IER_MSI;
76 	serial_out(up, UART_IER, up->ier);
77 }
78 
79 static void serial_pxa_stop_tx(struct uart_port *port)
80 {
81 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
82 
83 	if (up->ier & UART_IER_THRI) {
84 		up->ier &= ~UART_IER_THRI;
85 		serial_out(up, UART_IER, up->ier);
86 	}
87 }
88 
89 static void serial_pxa_stop_rx(struct uart_port *port)
90 {
91 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
92 
93 	up->ier &= ~UART_IER_RLSI;
94 	up->port.read_status_mask &= ~UART_LSR_DR;
95 	serial_out(up, UART_IER, up->ier);
96 }
97 
98 static inline void receive_chars(struct uart_pxa_port *up, int *status)
99 {
100 	unsigned int ch, flag;
101 	int max_count = 256;
102 
103 	do {
104 		/* work around Errata #20 according to
105 		 * Intel(R) PXA27x Processor Family
106 		 * Specification Update (May 2005)
107 		 *
108 		 * Step 2
109 		 * Disable the Reciever Time Out Interrupt via IER[RTOEI]
110 		 */
111 		up->ier &= ~UART_IER_RTOIE;
112 		serial_out(up, UART_IER, up->ier);
113 
114 		ch = serial_in(up, UART_RX);
115 		flag = TTY_NORMAL;
116 		up->port.icount.rx++;
117 
118 		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
119 				       UART_LSR_FE | UART_LSR_OE))) {
120 			/*
121 			 * For statistics only
122 			 */
123 			if (*status & UART_LSR_BI) {
124 				*status &= ~(UART_LSR_FE | UART_LSR_PE);
125 				up->port.icount.brk++;
126 				/*
127 				 * We do the SysRQ and SAK checking
128 				 * here because otherwise the break
129 				 * may get masked by ignore_status_mask
130 				 * or read_status_mask.
131 				 */
132 				if (uart_handle_break(&up->port))
133 					goto ignore_char;
134 			} else if (*status & UART_LSR_PE)
135 				up->port.icount.parity++;
136 			else if (*status & UART_LSR_FE)
137 				up->port.icount.frame++;
138 			if (*status & UART_LSR_OE)
139 				up->port.icount.overrun++;
140 
141 			/*
142 			 * Mask off conditions which should be ignored.
143 			 */
144 			*status &= up->port.read_status_mask;
145 
146 #ifdef CONFIG_SERIAL_PXA_CONSOLE
147 			if (up->port.line == up->port.cons->index) {
148 				/* Recover the break flag from console xmit */
149 				*status |= up->lsr_break_flag;
150 				up->lsr_break_flag = 0;
151 			}
152 #endif
153 			if (*status & UART_LSR_BI) {
154 				flag = TTY_BREAK;
155 			} else if (*status & UART_LSR_PE)
156 				flag = TTY_PARITY;
157 			else if (*status & UART_LSR_FE)
158 				flag = TTY_FRAME;
159 		}
160 
161 		if (uart_handle_sysrq_char(&up->port, ch))
162 			goto ignore_char;
163 
164 		uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
165 
166 	ignore_char:
167 		*status = serial_in(up, UART_LSR);
168 	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
169 	tty_flip_buffer_push(&up->port.state->port);
170 
171 	/* work around Errata #20 according to
172 	 * Intel(R) PXA27x Processor Family
173 	 * Specification Update (May 2005)
174 	 *
175 	 * Step 6:
176 	 * No more data in FIFO: Re-enable RTO interrupt via IER[RTOIE]
177 	 */
178 	up->ier |= UART_IER_RTOIE;
179 	serial_out(up, UART_IER, up->ier);
180 }
181 
182 static void transmit_chars(struct uart_pxa_port *up)
183 {
184 	struct circ_buf *xmit = &up->port.state->xmit;
185 	int count;
186 
187 	if (up->port.x_char) {
188 		serial_out(up, UART_TX, up->port.x_char);
189 		up->port.icount.tx++;
190 		up->port.x_char = 0;
191 		return;
192 	}
193 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
194 		serial_pxa_stop_tx(&up->port);
195 		return;
196 	}
197 
198 	count = up->port.fifosize / 2;
199 	do {
200 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
201 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
202 		up->port.icount.tx++;
203 		if (uart_circ_empty(xmit))
204 			break;
205 	} while (--count > 0);
206 
207 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
208 		uart_write_wakeup(&up->port);
209 
210 
211 	if (uart_circ_empty(xmit))
212 		serial_pxa_stop_tx(&up->port);
213 }
214 
215 static void serial_pxa_start_tx(struct uart_port *port)
216 {
217 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
218 
219 	if (!(up->ier & UART_IER_THRI)) {
220 		up->ier |= UART_IER_THRI;
221 		serial_out(up, UART_IER, up->ier);
222 	}
223 }
224 
225 /* should hold up->port.lock */
226 static inline void check_modem_status(struct uart_pxa_port *up)
227 {
228 	int status;
229 
230 	status = serial_in(up, UART_MSR);
231 
232 	if ((status & UART_MSR_ANY_DELTA) == 0)
233 		return;
234 
235 	if (status & UART_MSR_TERI)
236 		up->port.icount.rng++;
237 	if (status & UART_MSR_DDSR)
238 		up->port.icount.dsr++;
239 	if (status & UART_MSR_DDCD)
240 		uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
241 	if (status & UART_MSR_DCTS)
242 		uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
243 
244 	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
245 }
246 
247 /*
248  * This handles the interrupt from one port.
249  */
250 static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
251 {
252 	struct uart_pxa_port *up = dev_id;
253 	unsigned int iir, lsr;
254 
255 	iir = serial_in(up, UART_IIR);
256 	if (iir & UART_IIR_NO_INT)
257 		return IRQ_NONE;
258 	spin_lock(&up->port.lock);
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 	spin_unlock(&up->port.lock);
266 	return IRQ_HANDLED;
267 }
268 
269 static unsigned int serial_pxa_tx_empty(struct uart_port *port)
270 {
271 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
272 	unsigned long flags;
273 	unsigned int ret;
274 
275 	spin_lock_irqsave(&up->port.lock, flags);
276 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
277 	spin_unlock_irqrestore(&up->port.lock, flags);
278 
279 	return ret;
280 }
281 
282 static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
283 {
284 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
285 	unsigned char status;
286 	unsigned int ret;
287 
288 	status = serial_in(up, UART_MSR);
289 
290 	ret = 0;
291 	if (status & UART_MSR_DCD)
292 		ret |= TIOCM_CAR;
293 	if (status & UART_MSR_RI)
294 		ret |= TIOCM_RNG;
295 	if (status & UART_MSR_DSR)
296 		ret |= TIOCM_DSR;
297 	if (status & UART_MSR_CTS)
298 		ret |= TIOCM_CTS;
299 	return ret;
300 }
301 
302 static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
303 {
304 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
305 	unsigned char mcr = 0;
306 
307 	if (mctrl & TIOCM_RTS)
308 		mcr |= UART_MCR_RTS;
309 	if (mctrl & TIOCM_DTR)
310 		mcr |= UART_MCR_DTR;
311 	if (mctrl & TIOCM_OUT1)
312 		mcr |= UART_MCR_OUT1;
313 	if (mctrl & TIOCM_OUT2)
314 		mcr |= UART_MCR_OUT2;
315 	if (mctrl & TIOCM_LOOP)
316 		mcr |= UART_MCR_LOOP;
317 
318 	mcr |= up->mcr;
319 
320 	serial_out(up, UART_MCR, mcr);
321 }
322 
323 static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
324 {
325 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
326 	unsigned long flags;
327 
328 	spin_lock_irqsave(&up->port.lock, flags);
329 	if (break_state == -1)
330 		up->lcr |= UART_LCR_SBC;
331 	else
332 		up->lcr &= ~UART_LCR_SBC;
333 	serial_out(up, UART_LCR, up->lcr);
334 	spin_unlock_irqrestore(&up->port.lock, flags);
335 }
336 
337 static int serial_pxa_startup(struct uart_port *port)
338 {
339 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
340 	unsigned long flags;
341 	int retval;
342 
343 	if (port->line == 3) /* HWUART */
344 		up->mcr |= UART_MCR_AFE;
345 	else
346 		up->mcr = 0;
347 
348 	up->port.uartclk = clk_get_rate(up->clk);
349 
350 	/*
351 	 * Allocate the IRQ
352 	 */
353 	retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
354 	if (retval)
355 		return retval;
356 
357 	/*
358 	 * Clear the FIFO buffers and disable them.
359 	 * (they will be reenabled in set_termios())
360 	 */
361 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
362 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
363 			UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
364 	serial_out(up, UART_FCR, 0);
365 
366 	/*
367 	 * Clear the interrupt registers.
368 	 */
369 	(void) serial_in(up, UART_LSR);
370 	(void) serial_in(up, UART_RX);
371 	(void) serial_in(up, UART_IIR);
372 	(void) serial_in(up, UART_MSR);
373 
374 	/*
375 	 * Now, initialize the UART
376 	 */
377 	serial_out(up, UART_LCR, UART_LCR_WLEN8);
378 
379 	spin_lock_irqsave(&up->port.lock, flags);
380 	up->port.mctrl |= TIOCM_OUT2;
381 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
382 	spin_unlock_irqrestore(&up->port.lock, flags);
383 
384 	/*
385 	 * Finally, enable interrupts.  Note: Modem status interrupts
386 	 * are set via set_termios(), which will be occurring imminently
387 	 * anyway, so we don't enable them here.
388 	 */
389 	up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
390 	serial_out(up, UART_IER, up->ier);
391 
392 	/*
393 	 * And clear the interrupt registers again for luck.
394 	 */
395 	(void) serial_in(up, UART_LSR);
396 	(void) serial_in(up, UART_RX);
397 	(void) serial_in(up, UART_IIR);
398 	(void) serial_in(up, UART_MSR);
399 
400 	return 0;
401 }
402 
403 static void serial_pxa_shutdown(struct uart_port *port)
404 {
405 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
406 	unsigned long flags;
407 
408 	free_irq(up->port.irq, up);
409 
410 	/*
411 	 * Disable interrupts from this port
412 	 */
413 	up->ier = 0;
414 	serial_out(up, UART_IER, 0);
415 
416 	spin_lock_irqsave(&up->port.lock, flags);
417 	up->port.mctrl &= ~TIOCM_OUT2;
418 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
419 	spin_unlock_irqrestore(&up->port.lock, flags);
420 
421 	/*
422 	 * Disable break condition and FIFOs
423 	 */
424 	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
425 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
426 				  UART_FCR_CLEAR_RCVR |
427 				  UART_FCR_CLEAR_XMIT);
428 	serial_out(up, UART_FCR, 0);
429 }
430 
431 static void
432 serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
433 		       struct ktermios *old)
434 {
435 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
436 	unsigned char cval, fcr = 0;
437 	unsigned long flags;
438 	unsigned int baud, quot;
439 	unsigned int dll;
440 
441 	switch (termios->c_cflag & CSIZE) {
442 	case CS5:
443 		cval = UART_LCR_WLEN5;
444 		break;
445 	case CS6:
446 		cval = UART_LCR_WLEN6;
447 		break;
448 	case CS7:
449 		cval = UART_LCR_WLEN7;
450 		break;
451 	default:
452 	case CS8:
453 		cval = UART_LCR_WLEN8;
454 		break;
455 	}
456 
457 	if (termios->c_cflag & CSTOPB)
458 		cval |= UART_LCR_STOP;
459 	if (termios->c_cflag & PARENB)
460 		cval |= UART_LCR_PARITY;
461 	if (!(termios->c_cflag & PARODD))
462 		cval |= UART_LCR_EPAR;
463 
464 	/*
465 	 * Ask the core to calculate the divisor for us.
466 	 */
467 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
468 	quot = uart_get_divisor(port, baud);
469 
470 	if ((up->port.uartclk / quot) < (2400 * 16))
471 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
472 	else if ((up->port.uartclk / quot) < (230400 * 16))
473 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
474 	else
475 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
476 
477 	/*
478 	 * Ok, we're now changing the port state.  Do it with
479 	 * interrupts disabled.
480 	 */
481 	spin_lock_irqsave(&up->port.lock, flags);
482 
483 	/*
484 	 * Ensure the port will be enabled.
485 	 * This is required especially for serial console.
486 	 */
487 	up->ier |= UART_IER_UUE;
488 
489 	/*
490 	 * Update the per-port timeout.
491 	 */
492 	uart_update_timeout(port, termios->c_cflag, baud);
493 
494 	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
495 	if (termios->c_iflag & INPCK)
496 		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
497 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
498 		up->port.read_status_mask |= UART_LSR_BI;
499 
500 	/*
501 	 * Characters to ignore
502 	 */
503 	up->port.ignore_status_mask = 0;
504 	if (termios->c_iflag & IGNPAR)
505 		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
506 	if (termios->c_iflag & IGNBRK) {
507 		up->port.ignore_status_mask |= UART_LSR_BI;
508 		/*
509 		 * If we're ignoring parity and break indicators,
510 		 * ignore overruns too (for real raw support).
511 		 */
512 		if (termios->c_iflag & IGNPAR)
513 			up->port.ignore_status_mask |= UART_LSR_OE;
514 	}
515 
516 	/*
517 	 * ignore all characters if CREAD is not set
518 	 */
519 	if ((termios->c_cflag & CREAD) == 0)
520 		up->port.ignore_status_mask |= UART_LSR_DR;
521 
522 	/*
523 	 * CTS flow control flag and modem status interrupts
524 	 */
525 	up->ier &= ~UART_IER_MSI;
526 	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
527 		up->ier |= UART_IER_MSI;
528 
529 	serial_out(up, UART_IER, up->ier);
530 
531 	if (termios->c_cflag & CRTSCTS)
532 		up->mcr |= UART_MCR_AFE;
533 	else
534 		up->mcr &= ~UART_MCR_AFE;
535 
536 	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);	/* set DLAB */
537 	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
538 
539 	/*
540 	 * work around Errata #75 according to Intel(R) PXA27x Processor Family
541 	 * Specification Update (Nov 2005)
542 	 */
543 	dll = serial_in(up, UART_DLL);
544 	WARN_ON(dll != (quot & 0xff));
545 
546 	serial_out(up, UART_DLM, quot >> 8);		/* MS of divisor */
547 	serial_out(up, UART_LCR, cval);			/* reset DLAB */
548 	up->lcr = cval;					/* Save LCR */
549 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
550 	serial_out(up, UART_FCR, fcr);
551 	spin_unlock_irqrestore(&up->port.lock, flags);
552 }
553 
554 static void
555 serial_pxa_pm(struct uart_port *port, unsigned int state,
556 	      unsigned int oldstate)
557 {
558 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
559 
560 	if (!state)
561 		clk_prepare_enable(up->clk);
562 	else
563 		clk_disable_unprepare(up->clk);
564 }
565 
566 static void serial_pxa_release_port(struct uart_port *port)
567 {
568 }
569 
570 static int serial_pxa_request_port(struct uart_port *port)
571 {
572 	return 0;
573 }
574 
575 static void serial_pxa_config_port(struct uart_port *port, int flags)
576 {
577 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
578 	up->port.type = PORT_PXA;
579 }
580 
581 static int
582 serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
583 {
584 	/* we don't want the core code to modify any port params */
585 	return -EINVAL;
586 }
587 
588 static const char *
589 serial_pxa_type(struct uart_port *port)
590 {
591 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
592 	return up->name;
593 }
594 
595 static struct uart_pxa_port *serial_pxa_ports[4];
596 static struct uart_driver serial_pxa_reg;
597 
598 #ifdef CONFIG_SERIAL_PXA_CONSOLE
599 
600 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
601 
602 /*
603  *	Wait for transmitter & holding register to empty
604  */
605 static void wait_for_xmitr(struct uart_pxa_port *up)
606 {
607 	unsigned int status, tmout = 10000;
608 
609 	/* Wait up to 10ms for the character(s) to be sent. */
610 	do {
611 		status = serial_in(up, UART_LSR);
612 
613 		if (status & UART_LSR_BI)
614 			up->lsr_break_flag = UART_LSR_BI;
615 
616 		if (--tmout == 0)
617 			break;
618 		udelay(1);
619 	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
620 
621 	/* Wait up to 1s for flow control if necessary */
622 	if (up->port.flags & UPF_CONS_FLOW) {
623 		tmout = 1000000;
624 		while (--tmout &&
625 		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
626 			udelay(1);
627 	}
628 }
629 
630 static void serial_pxa_console_putchar(struct uart_port *port, int ch)
631 {
632 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
633 
634 	wait_for_xmitr(up);
635 	serial_out(up, UART_TX, ch);
636 }
637 
638 /*
639  * Print a string to the serial port trying not to disturb
640  * any possible real use of the port...
641  *
642  *	The console_lock must be held when we get here.
643  */
644 static void
645 serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
646 {
647 	struct uart_pxa_port *up = serial_pxa_ports[co->index];
648 	unsigned int ier;
649 	unsigned long flags;
650 	int locked = 1;
651 
652 	clk_enable(up->clk);
653 	local_irq_save(flags);
654 	if (up->port.sysrq)
655 		locked = 0;
656 	else if (oops_in_progress)
657 		locked = spin_trylock(&up->port.lock);
658 	else
659 		spin_lock(&up->port.lock);
660 
661 	/*
662 	 *	First save the IER then disable the interrupts
663 	 */
664 	ier = serial_in(up, UART_IER);
665 	serial_out(up, UART_IER, UART_IER_UUE);
666 
667 	uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
668 
669 	/*
670 	 *	Finally, wait for transmitter to become empty
671 	 *	and restore the IER
672 	 */
673 	wait_for_xmitr(up);
674 	serial_out(up, UART_IER, ier);
675 
676 	if (locked)
677 		spin_unlock(&up->port.lock);
678 	local_irq_restore(flags);
679 	clk_disable(up->clk);
680 
681 }
682 
683 #ifdef CONFIG_CONSOLE_POLL
684 /*
685  * Console polling routines for writing and reading from the uart while
686  * in an interrupt or debug context.
687  */
688 
689 static int serial_pxa_get_poll_char(struct uart_port *port)
690 {
691 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
692 	unsigned char lsr = serial_in(up, UART_LSR);
693 
694 	while (!(lsr & UART_LSR_DR))
695 		lsr = serial_in(up, UART_LSR);
696 
697 	return serial_in(up, UART_RX);
698 }
699 
700 
701 static void serial_pxa_put_poll_char(struct uart_port *port,
702 			 unsigned char c)
703 {
704 	unsigned int ier;
705 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
706 
707 	/*
708 	 *	First save the IER then disable the interrupts
709 	 */
710 	ier = serial_in(up, UART_IER);
711 	serial_out(up, UART_IER, UART_IER_UUE);
712 
713 	wait_for_xmitr(up);
714 	/*
715 	 *	Send the character out.
716 	 */
717 	serial_out(up, UART_TX, c);
718 
719 	/*
720 	 *	Finally, wait for transmitter to become empty
721 	 *	and restore the IER
722 	 */
723 	wait_for_xmitr(up);
724 	serial_out(up, UART_IER, ier);
725 }
726 
727 #endif /* CONFIG_CONSOLE_POLL */
728 
729 static int __init
730 serial_pxa_console_setup(struct console *co, char *options)
731 {
732 	struct uart_pxa_port *up;
733 	int baud = 9600;
734 	int bits = 8;
735 	int parity = 'n';
736 	int flow = 'n';
737 
738 	if (co->index == -1 || co->index >= serial_pxa_reg.nr)
739 		co->index = 0;
740 	up = serial_pxa_ports[co->index];
741 	if (!up)
742 		return -ENODEV;
743 
744 	if (options)
745 		uart_parse_options(options, &baud, &parity, &bits, &flow);
746 
747 	return uart_set_options(&up->port, co, baud, parity, bits, flow);
748 }
749 
750 static struct console serial_pxa_console = {
751 	.name		= "ttyS",
752 	.write		= serial_pxa_console_write,
753 	.device		= uart_console_device,
754 	.setup		= serial_pxa_console_setup,
755 	.flags		= CON_PRINTBUFFER,
756 	.index		= -1,
757 	.data		= &serial_pxa_reg,
758 };
759 
760 #define PXA_CONSOLE	&serial_pxa_console
761 #else
762 #define PXA_CONSOLE	NULL
763 #endif
764 
765 static const struct uart_ops serial_pxa_pops = {
766 	.tx_empty	= serial_pxa_tx_empty,
767 	.set_mctrl	= serial_pxa_set_mctrl,
768 	.get_mctrl	= serial_pxa_get_mctrl,
769 	.stop_tx	= serial_pxa_stop_tx,
770 	.start_tx	= serial_pxa_start_tx,
771 	.stop_rx	= serial_pxa_stop_rx,
772 	.enable_ms	= serial_pxa_enable_ms,
773 	.break_ctl	= serial_pxa_break_ctl,
774 	.startup	= serial_pxa_startup,
775 	.shutdown	= serial_pxa_shutdown,
776 	.set_termios	= serial_pxa_set_termios,
777 	.pm		= serial_pxa_pm,
778 	.type		= serial_pxa_type,
779 	.release_port	= serial_pxa_release_port,
780 	.request_port	= serial_pxa_request_port,
781 	.config_port	= serial_pxa_config_port,
782 	.verify_port	= serial_pxa_verify_port,
783 #if defined(CONFIG_CONSOLE_POLL) && defined(CONFIG_SERIAL_PXA_CONSOLE)
784 	.poll_get_char = serial_pxa_get_poll_char,
785 	.poll_put_char = serial_pxa_put_poll_char,
786 #endif
787 };
788 
789 static struct uart_driver serial_pxa_reg = {
790 	.owner		= THIS_MODULE,
791 	.driver_name	= "PXA serial",
792 	.dev_name	= "ttyS",
793 	.major		= TTY_MAJOR,
794 	.minor		= 64,
795 	.nr		= 4,
796 	.cons		= PXA_CONSOLE,
797 };
798 
799 #ifdef CONFIG_PM
800 static int serial_pxa_suspend(struct device *dev)
801 {
802         struct uart_pxa_port *sport = dev_get_drvdata(dev);
803 
804         if (sport)
805                 uart_suspend_port(&serial_pxa_reg, &sport->port);
806 
807         return 0;
808 }
809 
810 static int serial_pxa_resume(struct device *dev)
811 {
812         struct uart_pxa_port *sport = dev_get_drvdata(dev);
813 
814         if (sport)
815                 uart_resume_port(&serial_pxa_reg, &sport->port);
816 
817         return 0;
818 }
819 
820 static const struct dev_pm_ops serial_pxa_pm_ops = {
821 	.suspend	= serial_pxa_suspend,
822 	.resume		= serial_pxa_resume,
823 };
824 #endif
825 
826 static const struct of_device_id serial_pxa_dt_ids[] = {
827 	{ .compatible = "mrvl,pxa-uart", },
828 	{ .compatible = "mrvl,mmp-uart", },
829 	{}
830 };
831 
832 static int serial_pxa_probe_dt(struct platform_device *pdev,
833 			       struct uart_pxa_port *sport)
834 {
835 	struct device_node *np = pdev->dev.of_node;
836 	int ret;
837 
838 	if (!np)
839 		return 1;
840 
841 	ret = of_alias_get_id(np, "serial");
842 	if (ret < 0) {
843 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
844 		return ret;
845 	}
846 	sport->port.line = ret;
847 	return 0;
848 }
849 
850 static int serial_pxa_probe(struct platform_device *dev)
851 {
852 	struct uart_pxa_port *sport;
853 	struct resource *mmres, *irqres;
854 	int ret;
855 
856 	mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
857 	irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
858 	if (!mmres || !irqres)
859 		return -ENODEV;
860 
861 	sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
862 	if (!sport)
863 		return -ENOMEM;
864 
865 	sport->clk = clk_get(&dev->dev, NULL);
866 	if (IS_ERR(sport->clk)) {
867 		ret = PTR_ERR(sport->clk);
868 		goto err_free;
869 	}
870 
871 	ret = clk_prepare(sport->clk);
872 	if (ret) {
873 		clk_put(sport->clk);
874 		goto err_free;
875 	}
876 
877 	sport->port.type = PORT_PXA;
878 	sport->port.iotype = UPIO_MEM;
879 	sport->port.mapbase = mmres->start;
880 	sport->port.irq = irqres->start;
881 	sport->port.fifosize = 64;
882 	sport->port.ops = &serial_pxa_pops;
883 	sport->port.dev = &dev->dev;
884 	sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
885 	sport->port.uartclk = clk_get_rate(sport->clk);
886 
887 	ret = serial_pxa_probe_dt(dev, sport);
888 	if (ret > 0)
889 		sport->port.line = dev->id;
890 	else if (ret < 0)
891 		goto err_clk;
892 	snprintf(sport->name, PXA_NAME_LEN - 1, "UART%d", sport->port.line + 1);
893 
894 	sport->port.membase = ioremap(mmres->start, resource_size(mmres));
895 	if (!sport->port.membase) {
896 		ret = -ENOMEM;
897 		goto err_clk;
898 	}
899 
900 	serial_pxa_ports[sport->port.line] = sport;
901 
902 	uart_add_one_port(&serial_pxa_reg, &sport->port);
903 	platform_set_drvdata(dev, sport);
904 
905 	return 0;
906 
907  err_clk:
908 	clk_unprepare(sport->clk);
909 	clk_put(sport->clk);
910  err_free:
911 	kfree(sport);
912 	return ret;
913 }
914 
915 static struct platform_driver serial_pxa_driver = {
916         .probe          = serial_pxa_probe,
917 
918 	.driver		= {
919 	        .name	= "pxa2xx-uart",
920 #ifdef CONFIG_PM
921 		.pm	= &serial_pxa_pm_ops,
922 #endif
923 		.suppress_bind_attrs = true,
924 		.of_match_table = serial_pxa_dt_ids,
925 	},
926 };
927 
928 
929 /* 8250 driver for PXA serial ports should be used */
930 static int __init serial_pxa_init(void)
931 {
932 	int ret;
933 
934 	ret = uart_register_driver(&serial_pxa_reg);
935 	if (ret != 0)
936 		return ret;
937 
938 	ret = platform_driver_register(&serial_pxa_driver);
939 	if (ret != 0)
940 		uart_unregister_driver(&serial_pxa_reg);
941 
942 	return ret;
943 }
944 device_initcall(serial_pxa_init);
945