xref: /openbmc/linux/drivers/tty/serial/pxa.c (revision 089a49b6)
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 	unsigned int ch, flag;
102 	int max_count = 256;
103 
104 	do {
105 		/* work around Errata #20 according to
106 		 * Intel(R) PXA27x Processor Family
107 		 * Specification Update (May 2005)
108 		 *
109 		 * Step 2
110 		 * Disable the Reciever Time Out Interrupt via IER[RTOEI]
111 		 */
112 		up->ier &= ~UART_IER_RTOIE;
113 		serial_out(up, UART_IER, up->ier);
114 
115 		ch = serial_in(up, UART_RX);
116 		flag = TTY_NORMAL;
117 		up->port.icount.rx++;
118 
119 		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
120 				       UART_LSR_FE | UART_LSR_OE))) {
121 			/*
122 			 * For statistics only
123 			 */
124 			if (*status & UART_LSR_BI) {
125 				*status &= ~(UART_LSR_FE | UART_LSR_PE);
126 				up->port.icount.brk++;
127 				/*
128 				 * We do the SysRQ and SAK checking
129 				 * here because otherwise the break
130 				 * may get masked by ignore_status_mask
131 				 * or read_status_mask.
132 				 */
133 				if (uart_handle_break(&up->port))
134 					goto ignore_char;
135 			} else if (*status & UART_LSR_PE)
136 				up->port.icount.parity++;
137 			else if (*status & UART_LSR_FE)
138 				up->port.icount.frame++;
139 			if (*status & UART_LSR_OE)
140 				up->port.icount.overrun++;
141 
142 			/*
143 			 * Mask off conditions which should be ignored.
144 			 */
145 			*status &= up->port.read_status_mask;
146 
147 #ifdef CONFIG_SERIAL_PXA_CONSOLE
148 			if (up->port.line == up->port.cons->index) {
149 				/* Recover the break flag from console xmit */
150 				*status |= up->lsr_break_flag;
151 				up->lsr_break_flag = 0;
152 			}
153 #endif
154 			if (*status & UART_LSR_BI) {
155 				flag = TTY_BREAK;
156 			} else if (*status & UART_LSR_PE)
157 				flag = TTY_PARITY;
158 			else if (*status & UART_LSR_FE)
159 				flag = TTY_FRAME;
160 		}
161 
162 		if (uart_handle_sysrq_char(&up->port, ch))
163 			goto ignore_char;
164 
165 		uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
166 
167 	ignore_char:
168 		*status = serial_in(up, UART_LSR);
169 	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
170 	tty_flip_buffer_push(&up->port.state->port);
171 
172 	/* work around Errata #20 according to
173 	 * Intel(R) PXA27x Processor Family
174 	 * Specification Update (May 2005)
175 	 *
176 	 * Step 6:
177 	 * No more data in FIFO: Re-enable RTO interrupt via IER[RTOIE]
178 	 */
179 	up->ier |= UART_IER_RTOIE;
180 	serial_out(up, UART_IER, up->ier);
181 }
182 
183 static void transmit_chars(struct uart_pxa_port *up)
184 {
185 	struct circ_buf *xmit = &up->port.state->xmit;
186 	int count;
187 
188 	if (up->port.x_char) {
189 		serial_out(up, UART_TX, up->port.x_char);
190 		up->port.icount.tx++;
191 		up->port.x_char = 0;
192 		return;
193 	}
194 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
195 		serial_pxa_stop_tx(&up->port);
196 		return;
197 	}
198 
199 	count = up->port.fifosize / 2;
200 	do {
201 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
202 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
203 		up->port.icount.tx++;
204 		if (uart_circ_empty(xmit))
205 			break;
206 	} while (--count > 0);
207 
208 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
209 		uart_write_wakeup(&up->port);
210 
211 
212 	if (uart_circ_empty(xmit))
213 		serial_pxa_stop_tx(&up->port);
214 }
215 
216 static void serial_pxa_start_tx(struct uart_port *port)
217 {
218 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
219 
220 	if (!(up->ier & UART_IER_THRI)) {
221 		up->ier |= UART_IER_THRI;
222 		serial_out(up, UART_IER, up->ier);
223 	}
224 }
225 
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 	lsr = serial_in(up, UART_LSR);
259 	if (lsr & UART_LSR_DR)
260 		receive_chars(up, &lsr);
261 	check_modem_status(up);
262 	if (lsr & UART_LSR_THRE)
263 		transmit_chars(up);
264 	return IRQ_HANDLED;
265 }
266 
267 static unsigned int serial_pxa_tx_empty(struct uart_port *port)
268 {
269 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
270 	unsigned long flags;
271 	unsigned int ret;
272 
273 	spin_lock_irqsave(&up->port.lock, flags);
274 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
275 	spin_unlock_irqrestore(&up->port.lock, flags);
276 
277 	return ret;
278 }
279 
280 static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
281 {
282 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
283 	unsigned char status;
284 	unsigned int ret;
285 
286 	status = serial_in(up, UART_MSR);
287 
288 	ret = 0;
289 	if (status & UART_MSR_DCD)
290 		ret |= TIOCM_CAR;
291 	if (status & UART_MSR_RI)
292 		ret |= TIOCM_RNG;
293 	if (status & UART_MSR_DSR)
294 		ret |= TIOCM_DSR;
295 	if (status & UART_MSR_CTS)
296 		ret |= TIOCM_CTS;
297 	return ret;
298 }
299 
300 static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
301 {
302 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
303 	unsigned char mcr = 0;
304 
305 	if (mctrl & TIOCM_RTS)
306 		mcr |= UART_MCR_RTS;
307 	if (mctrl & TIOCM_DTR)
308 		mcr |= UART_MCR_DTR;
309 	if (mctrl & TIOCM_OUT1)
310 		mcr |= UART_MCR_OUT1;
311 	if (mctrl & TIOCM_OUT2)
312 		mcr |= UART_MCR_OUT2;
313 	if (mctrl & TIOCM_LOOP)
314 		mcr |= UART_MCR_LOOP;
315 
316 	mcr |= up->mcr;
317 
318 	serial_out(up, UART_MCR, mcr);
319 }
320 
321 static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
322 {
323 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
324 	unsigned long flags;
325 
326 	spin_lock_irqsave(&up->port.lock, flags);
327 	if (break_state == -1)
328 		up->lcr |= UART_LCR_SBC;
329 	else
330 		up->lcr &= ~UART_LCR_SBC;
331 	serial_out(up, UART_LCR, up->lcr);
332 	spin_unlock_irqrestore(&up->port.lock, flags);
333 }
334 
335 static int serial_pxa_startup(struct uart_port *port)
336 {
337 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
338 	unsigned long flags;
339 	int retval;
340 
341 	if (port->line == 3) /* HWUART */
342 		up->mcr |= UART_MCR_AFE;
343 	else
344 		up->mcr = 0;
345 
346 	up->port.uartclk = clk_get_rate(up->clk);
347 
348 	/*
349 	 * Allocate the IRQ
350 	 */
351 	retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
352 	if (retval)
353 		return retval;
354 
355 	/*
356 	 * Clear the FIFO buffers and disable them.
357 	 * (they will be reenabled in set_termios())
358 	 */
359 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
360 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
361 			UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
362 	serial_out(up, UART_FCR, 0);
363 
364 	/*
365 	 * Clear the interrupt registers.
366 	 */
367 	(void) serial_in(up, UART_LSR);
368 	(void) serial_in(up, UART_RX);
369 	(void) serial_in(up, UART_IIR);
370 	(void) serial_in(up, UART_MSR);
371 
372 	/*
373 	 * Now, initialize the UART
374 	 */
375 	serial_out(up, UART_LCR, UART_LCR_WLEN8);
376 
377 	spin_lock_irqsave(&up->port.lock, flags);
378 	up->port.mctrl |= TIOCM_OUT2;
379 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
380 	spin_unlock_irqrestore(&up->port.lock, flags);
381 
382 	/*
383 	 * Finally, enable interrupts.  Note: Modem status interrupts
384 	 * are set via set_termios(), which will be occurring imminently
385 	 * anyway, so we don't enable them here.
386 	 */
387 	up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
388 	serial_out(up, UART_IER, up->ier);
389 
390 	/*
391 	 * And clear the interrupt registers again for luck.
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 	return 0;
399 }
400 
401 static void serial_pxa_shutdown(struct uart_port *port)
402 {
403 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
404 	unsigned long flags;
405 
406 	free_irq(up->port.irq, up);
407 
408 	/*
409 	 * Disable interrupts from this port
410 	 */
411 	up->ier = 0;
412 	serial_out(up, UART_IER, 0);
413 
414 	spin_lock_irqsave(&up->port.lock, flags);
415 	up->port.mctrl &= ~TIOCM_OUT2;
416 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
417 	spin_unlock_irqrestore(&up->port.lock, flags);
418 
419 	/*
420 	 * Disable break condition and FIFOs
421 	 */
422 	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
423 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
424 				  UART_FCR_CLEAR_RCVR |
425 				  UART_FCR_CLEAR_XMIT);
426 	serial_out(up, UART_FCR, 0);
427 }
428 
429 static void
430 serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
431 		       struct ktermios *old)
432 {
433 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
434 	unsigned char cval, fcr = 0;
435 	unsigned long flags;
436 	unsigned int baud, quot;
437 	unsigned int dll;
438 
439 	switch (termios->c_cflag & CSIZE) {
440 	case CS5:
441 		cval = UART_LCR_WLEN5;
442 		break;
443 	case CS6:
444 		cval = UART_LCR_WLEN6;
445 		break;
446 	case CS7:
447 		cval = UART_LCR_WLEN7;
448 		break;
449 	default:
450 	case CS8:
451 		cval = UART_LCR_WLEN8;
452 		break;
453 	}
454 
455 	if (termios->c_cflag & CSTOPB)
456 		cval |= UART_LCR_STOP;
457 	if (termios->c_cflag & PARENB)
458 		cval |= UART_LCR_PARITY;
459 	if (!(termios->c_cflag & PARODD))
460 		cval |= UART_LCR_EPAR;
461 
462 	/*
463 	 * Ask the core to calculate the divisor for us.
464 	 */
465 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
466 	quot = uart_get_divisor(port, baud);
467 
468 	if ((up->port.uartclk / quot) < (2400 * 16))
469 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
470 	else if ((up->port.uartclk / quot) < (230400 * 16))
471 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
472 	else
473 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
474 
475 	/*
476 	 * Ok, we're now changing the port state.  Do it with
477 	 * interrupts disabled.
478 	 */
479 	spin_lock_irqsave(&up->port.lock, flags);
480 
481 	/*
482 	 * Ensure the port will be enabled.
483 	 * This is required especially for serial console.
484 	 */
485 	up->ier |= UART_IER_UUE;
486 
487 	/*
488 	 * Update the per-port timeout.
489 	 */
490 	uart_update_timeout(port, termios->c_cflag, baud);
491 
492 	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
493 	if (termios->c_iflag & INPCK)
494 		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
495 	if (termios->c_iflag & (BRKINT | PARMRK))
496 		up->port.read_status_mask |= UART_LSR_BI;
497 
498 	/*
499 	 * Characters to ignore
500 	 */
501 	up->port.ignore_status_mask = 0;
502 	if (termios->c_iflag & IGNPAR)
503 		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
504 	if (termios->c_iflag & IGNBRK) {
505 		up->port.ignore_status_mask |= UART_LSR_BI;
506 		/*
507 		 * If we're ignoring parity and break indicators,
508 		 * ignore overruns too (for real raw support).
509 		 */
510 		if (termios->c_iflag & IGNPAR)
511 			up->port.ignore_status_mask |= UART_LSR_OE;
512 	}
513 
514 	/*
515 	 * ignore all characters if CREAD is not set
516 	 */
517 	if ((termios->c_cflag & CREAD) == 0)
518 		up->port.ignore_status_mask |= UART_LSR_DR;
519 
520 	/*
521 	 * CTS flow control flag and modem status interrupts
522 	 */
523 	up->ier &= ~UART_IER_MSI;
524 	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
525 		up->ier |= UART_IER_MSI;
526 
527 	serial_out(up, UART_IER, up->ier);
528 
529 	if (termios->c_cflag & CRTSCTS)
530 		up->mcr |= UART_MCR_AFE;
531 	else
532 		up->mcr &= ~UART_MCR_AFE;
533 
534 	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);	/* set DLAB */
535 	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
536 
537 	/*
538 	 * work around Errata #75 according to Intel(R) PXA27x Processor Family
539 	 * Specification Update (Nov 2005)
540 	 */
541 	dll = serial_in(up, UART_DLL);
542 	WARN_ON(dll != (quot & 0xff));
543 
544 	serial_out(up, UART_DLM, quot >> 8);		/* MS of divisor */
545 	serial_out(up, UART_LCR, cval);			/* reset DLAB */
546 	up->lcr = cval;					/* Save LCR */
547 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
548 	serial_out(up, UART_FCR, fcr);
549 	spin_unlock_irqrestore(&up->port.lock, flags);
550 }
551 
552 static void
553 serial_pxa_pm(struct uart_port *port, unsigned int state,
554 	      unsigned int oldstate)
555 {
556 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
557 
558 	if (!state)
559 		clk_prepare_enable(up->clk);
560 	else
561 		clk_disable_unprepare(up->clk);
562 }
563 
564 static void serial_pxa_release_port(struct uart_port *port)
565 {
566 }
567 
568 static int serial_pxa_request_port(struct uart_port *port)
569 {
570 	return 0;
571 }
572 
573 static void serial_pxa_config_port(struct uart_port *port, int flags)
574 {
575 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
576 	up->port.type = PORT_PXA;
577 }
578 
579 static int
580 serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
581 {
582 	/* we don't want the core code to modify any port params */
583 	return -EINVAL;
584 }
585 
586 static const char *
587 serial_pxa_type(struct uart_port *port)
588 {
589 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
590 	return up->name;
591 }
592 
593 static struct uart_pxa_port *serial_pxa_ports[4];
594 static struct uart_driver serial_pxa_reg;
595 
596 #ifdef CONFIG_SERIAL_PXA_CONSOLE
597 
598 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
599 
600 /*
601  *	Wait for transmitter & holding register to empty
602  */
603 static inline void wait_for_xmitr(struct uart_pxa_port *up)
604 {
605 	unsigned int status, tmout = 10000;
606 
607 	/* Wait up to 10ms for the character(s) to be sent. */
608 	do {
609 		status = serial_in(up, UART_LSR);
610 
611 		if (status & UART_LSR_BI)
612 			up->lsr_break_flag = UART_LSR_BI;
613 
614 		if (--tmout == 0)
615 			break;
616 		udelay(1);
617 	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
618 
619 	/* Wait up to 1s for flow control if necessary */
620 	if (up->port.flags & UPF_CONS_FLOW) {
621 		tmout = 1000000;
622 		while (--tmout &&
623 		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
624 			udelay(1);
625 	}
626 }
627 
628 static void serial_pxa_console_putchar(struct uart_port *port, int ch)
629 {
630 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
631 
632 	wait_for_xmitr(up);
633 	serial_out(up, UART_TX, ch);
634 }
635 
636 /*
637  * Print a string to the serial port trying not to disturb
638  * any possible real use of the port...
639  *
640  *	The console_lock must be held when we get here.
641  */
642 static void
643 serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
644 {
645 	struct uart_pxa_port *up = serial_pxa_ports[co->index];
646 	unsigned int ier;
647 	unsigned long flags;
648 	int locked = 1;
649 
650 	clk_enable(up->clk);
651 	local_irq_save(flags);
652 	if (up->port.sysrq)
653 		locked = 0;
654 	else if (oops_in_progress)
655 		locked = spin_trylock(&up->port.lock);
656 	else
657 		spin_lock(&up->port.lock);
658 
659 	/*
660 	 *	First save the IER then disable the interrupts
661 	 */
662 	ier = serial_in(up, UART_IER);
663 	serial_out(up, UART_IER, UART_IER_UUE);
664 
665 	uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
666 
667 	/*
668 	 *	Finally, wait for transmitter to become empty
669 	 *	and restore the IER
670 	 */
671 	wait_for_xmitr(up);
672 	serial_out(up, UART_IER, ier);
673 
674 	if (locked)
675 		spin_unlock(&up->port.lock);
676 	local_irq_restore(flags);
677 	clk_disable(up->clk);
678 
679 }
680 
681 #ifdef CONFIG_CONSOLE_POLL
682 /*
683  * Console polling routines for writing and reading from the uart while
684  * in an interrupt or debug context.
685  */
686 
687 static int serial_pxa_get_poll_char(struct uart_port *port)
688 {
689 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
690 	unsigned char lsr = serial_in(up, UART_LSR);
691 
692 	while (!(lsr & UART_LSR_DR))
693 		lsr = serial_in(up, UART_LSR);
694 
695 	return serial_in(up, UART_RX);
696 }
697 
698 
699 static void serial_pxa_put_poll_char(struct uart_port *port,
700 			 unsigned char c)
701 {
702 	unsigned int ier;
703 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
704 
705 	/*
706 	 *	First save the IER then disable the interrupts
707 	 */
708 	ier = serial_in(up, UART_IER);
709 	serial_out(up, UART_IER, UART_IER_UUE);
710 
711 	wait_for_xmitr(up);
712 	/*
713 	 *	Send the character out.
714 	 *	If a LF, also do CR...
715 	 */
716 	serial_out(up, UART_TX, c);
717 	if (c == 10) {
718 		wait_for_xmitr(up);
719 		serial_out(up, UART_TX, 13);
720 	}
721 
722 	/*
723 	 *	Finally, wait for transmitter to become empty
724 	 *	and restore the IER
725 	 */
726 	wait_for_xmitr(up);
727 	serial_out(up, UART_IER, ier);
728 }
729 
730 #endif /* CONFIG_CONSOLE_POLL */
731 
732 static int __init
733 serial_pxa_console_setup(struct console *co, char *options)
734 {
735 	struct uart_pxa_port *up;
736 	int baud = 9600;
737 	int bits = 8;
738 	int parity = 'n';
739 	int flow = 'n';
740 
741 	if (co->index == -1 || co->index >= serial_pxa_reg.nr)
742 		co->index = 0;
743 	up = serial_pxa_ports[co->index];
744 	if (!up)
745 		return -ENODEV;
746 
747 	if (options)
748 		uart_parse_options(options, &baud, &parity, &bits, &flow);
749 
750 	return uart_set_options(&up->port, co, baud, parity, bits, flow);
751 }
752 
753 static struct console serial_pxa_console = {
754 	.name		= "ttyS",
755 	.write		= serial_pxa_console_write,
756 	.device		= uart_console_device,
757 	.setup		= serial_pxa_console_setup,
758 	.flags		= CON_PRINTBUFFER,
759 	.index		= -1,
760 	.data		= &serial_pxa_reg,
761 };
762 
763 #define PXA_CONSOLE	&serial_pxa_console
764 #else
765 #define PXA_CONSOLE	NULL
766 #endif
767 
768 static struct uart_ops serial_pxa_pops = {
769 	.tx_empty	= serial_pxa_tx_empty,
770 	.set_mctrl	= serial_pxa_set_mctrl,
771 	.get_mctrl	= serial_pxa_get_mctrl,
772 	.stop_tx	= serial_pxa_stop_tx,
773 	.start_tx	= serial_pxa_start_tx,
774 	.stop_rx	= serial_pxa_stop_rx,
775 	.enable_ms	= serial_pxa_enable_ms,
776 	.break_ctl	= serial_pxa_break_ctl,
777 	.startup	= serial_pxa_startup,
778 	.shutdown	= serial_pxa_shutdown,
779 	.set_termios	= serial_pxa_set_termios,
780 	.pm		= serial_pxa_pm,
781 	.type		= serial_pxa_type,
782 	.release_port	= serial_pxa_release_port,
783 	.request_port	= serial_pxa_request_port,
784 	.config_port	= serial_pxa_config_port,
785 	.verify_port	= serial_pxa_verify_port,
786 #ifdef CONFIG_CONSOLE_POLL
787 	.poll_get_char = serial_pxa_get_poll_char,
788 	.poll_put_char = serial_pxa_put_poll_char,
789 #endif
790 };
791 
792 static struct uart_driver serial_pxa_reg = {
793 	.owner		= THIS_MODULE,
794 	.driver_name	= "PXA serial",
795 	.dev_name	= "ttyS",
796 	.major		= TTY_MAJOR,
797 	.minor		= 64,
798 	.nr		= 4,
799 	.cons		= PXA_CONSOLE,
800 };
801 
802 #ifdef CONFIG_PM
803 static int serial_pxa_suspend(struct device *dev)
804 {
805         struct uart_pxa_port *sport = dev_get_drvdata(dev);
806 
807         if (sport)
808                 uart_suspend_port(&serial_pxa_reg, &sport->port);
809 
810         return 0;
811 }
812 
813 static int serial_pxa_resume(struct device *dev)
814 {
815         struct uart_pxa_port *sport = dev_get_drvdata(dev);
816 
817         if (sport)
818                 uart_resume_port(&serial_pxa_reg, &sport->port);
819 
820         return 0;
821 }
822 
823 static const struct dev_pm_ops serial_pxa_pm_ops = {
824 	.suspend	= serial_pxa_suspend,
825 	.resume		= serial_pxa_resume,
826 };
827 #endif
828 
829 static struct of_device_id serial_pxa_dt_ids[] = {
830 	{ .compatible = "mrvl,pxa-uart", },
831 	{ .compatible = "mrvl,mmp-uart", },
832 	{}
833 };
834 MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
835 
836 static int serial_pxa_probe_dt(struct platform_device *pdev,
837 			       struct uart_pxa_port *sport)
838 {
839 	struct device_node *np = pdev->dev.of_node;
840 	int ret;
841 
842 	if (!np)
843 		return 1;
844 
845 	ret = of_alias_get_id(np, "serial");
846 	if (ret < 0) {
847 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
848 		return ret;
849 	}
850 	sport->port.line = ret;
851 	return 0;
852 }
853 
854 static int serial_pxa_probe(struct platform_device *dev)
855 {
856 	struct uart_pxa_port *sport;
857 	struct resource *mmres, *irqres;
858 	int ret;
859 
860 	mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
861 	irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
862 	if (!mmres || !irqres)
863 		return -ENODEV;
864 
865 	sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
866 	if (!sport)
867 		return -ENOMEM;
868 
869 	sport->clk = clk_get(&dev->dev, NULL);
870 	if (IS_ERR(sport->clk)) {
871 		ret = PTR_ERR(sport->clk);
872 		goto err_free;
873 	}
874 
875 	ret = clk_prepare(sport->clk);
876 	if (ret) {
877 		clk_put(sport->clk);
878 		goto err_free;
879 	}
880 
881 	sport->port.type = PORT_PXA;
882 	sport->port.iotype = UPIO_MEM;
883 	sport->port.mapbase = mmres->start;
884 	sport->port.irq = irqres->start;
885 	sport->port.fifosize = 64;
886 	sport->port.ops = &serial_pxa_pops;
887 	sport->port.dev = &dev->dev;
888 	sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
889 	sport->port.uartclk = clk_get_rate(sport->clk);
890 
891 	ret = serial_pxa_probe_dt(dev, sport);
892 	if (ret > 0)
893 		sport->port.line = dev->id;
894 	else if (ret < 0)
895 		goto err_clk;
896 	snprintf(sport->name, PXA_NAME_LEN - 1, "UART%d", sport->port.line + 1);
897 
898 	sport->port.membase = ioremap(mmres->start, resource_size(mmres));
899 	if (!sport->port.membase) {
900 		ret = -ENOMEM;
901 		goto err_clk;
902 	}
903 
904 	serial_pxa_ports[sport->port.line] = sport;
905 
906 	uart_add_one_port(&serial_pxa_reg, &sport->port);
907 	platform_set_drvdata(dev, sport);
908 
909 	return 0;
910 
911  err_clk:
912 	clk_unprepare(sport->clk);
913 	clk_put(sport->clk);
914  err_free:
915 	kfree(sport);
916 	return ret;
917 }
918 
919 static int serial_pxa_remove(struct platform_device *dev)
920 {
921 	struct uart_pxa_port *sport = platform_get_drvdata(dev);
922 
923 	uart_remove_one_port(&serial_pxa_reg, &sport->port);
924 
925 	clk_unprepare(sport->clk);
926 	clk_put(sport->clk);
927 	kfree(sport);
928 
929 	return 0;
930 }
931 
932 static struct platform_driver serial_pxa_driver = {
933         .probe          = serial_pxa_probe,
934         .remove         = serial_pxa_remove,
935 
936 	.driver		= {
937 	        .name	= "pxa2xx-uart",
938 		.owner	= THIS_MODULE,
939 #ifdef CONFIG_PM
940 		.pm	= &serial_pxa_pm_ops,
941 #endif
942 		.of_match_table = serial_pxa_dt_ids,
943 	},
944 };
945 
946 static int __init serial_pxa_init(void)
947 {
948 	int ret;
949 
950 	ret = uart_register_driver(&serial_pxa_reg);
951 	if (ret != 0)
952 		return ret;
953 
954 	ret = platform_driver_register(&serial_pxa_driver);
955 	if (ret != 0)
956 		uart_unregister_driver(&serial_pxa_reg);
957 
958 	return ret;
959 }
960 
961 static void __exit serial_pxa_exit(void)
962 {
963 	platform_driver_unregister(&serial_pxa_driver);
964 	uart_unregister_driver(&serial_pxa_reg);
965 }
966 
967 module_init(serial_pxa_init);
968 module_exit(serial_pxa_exit);
969 
970 MODULE_LICENSE("GPL");
971 MODULE_ALIAS("platform:pxa2xx-uart");
972