xref: /linux/drivers/tty/serial/pxa.c (revision 9bacbced0e32204deb8b9d011279f9beddd8c2ef)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  Based on drivers/serial/8250.c by Russell King.
4  *
5  *  Author:	Nicolas Pitre
6  *  Created:	Feb 20, 2003
7  *  Copyright:	(C) 2003 Monta Vista Software, Inc.
8  *
9  * Note 1: This driver is made separate from the already too overloaded
10  * 8250.c because it needs some kirks of its own and that'll make it
11  * easier to add DMA support.
12  *
13  * Note 2: I'm too sick of device allocation policies for serial ports.
14  * If someone else wants to request an "official" allocation of major/minor
15  * for this driver please be my guest.  And don't forget that new hardware
16  * to come from Intel might have more than 3 or 4 of those UARTs.  Let's
17  * hope for a better port registration and dynamic device allocation scheme
18  * with the serial core maintainer satisfaction to appear soon.
19  */
20 
21 
22 #if defined(CONFIG_SERIAL_PXA_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
23 #define SUPPORT_SYSRQ
24 #endif
25 
26 #include <linux/ioport.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
29 #include <linux/sysrq.h>
30 #include <linux/serial_reg.h>
31 #include <linux/circ_buf.h>
32 #include <linux/delay.h>
33 #include <linux/interrupt.h>
34 #include <linux/of.h>
35 #include <linux/platform_device.h>
36 #include <linux/tty.h>
37 #include <linux/tty_flip.h>
38 #include <linux/serial_core.h>
39 #include <linux/clk.h>
40 #include <linux/io.h>
41 #include <linux/slab.h>
42 
43 #define PXA_NAME_LEN		8
44 
45 struct uart_pxa_port {
46 	struct uart_port        port;
47 	unsigned char           ier;
48 	unsigned char           lcr;
49 	unsigned char           mcr;
50 	unsigned int            lsr_break_flag;
51 	struct clk		*clk;
52 	char			name[PXA_NAME_LEN];
53 };
54 
55 static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
56 {
57 	offset <<= 2;
58 	return readl(up->port.membase + offset);
59 }
60 
61 static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
62 {
63 	offset <<= 2;
64 	writel(value, up->port.membase + offset);
65 }
66 
67 static void serial_pxa_enable_ms(struct uart_port *port)
68 {
69 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
70 
71 	up->ier |= UART_IER_MSI;
72 	serial_out(up, UART_IER, up->ier);
73 }
74 
75 static void serial_pxa_stop_tx(struct uart_port *port)
76 {
77 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
78 
79 	if (up->ier & UART_IER_THRI) {
80 		up->ier &= ~UART_IER_THRI;
81 		serial_out(up, UART_IER, up->ier);
82 	}
83 }
84 
85 static void serial_pxa_stop_rx(struct uart_port *port)
86 {
87 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
88 
89 	up->ier &= ~UART_IER_RLSI;
90 	up->port.read_status_mask &= ~UART_LSR_DR;
91 	serial_out(up, UART_IER, up->ier);
92 }
93 
94 static inline void receive_chars(struct uart_pxa_port *up, int *status)
95 {
96 	unsigned int ch, flag;
97 	int max_count = 256;
98 
99 	do {
100 		/* work around Errata #20 according to
101 		 * Intel(R) PXA27x Processor Family
102 		 * Specification Update (May 2005)
103 		 *
104 		 * Step 2
105 		 * Disable the Reciever Time Out Interrupt via IER[RTOEI]
106 		 */
107 		up->ier &= ~UART_IER_RTOIE;
108 		serial_out(up, UART_IER, up->ier);
109 
110 		ch = serial_in(up, UART_RX);
111 		flag = TTY_NORMAL;
112 		up->port.icount.rx++;
113 
114 		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
115 				       UART_LSR_FE | UART_LSR_OE))) {
116 			/*
117 			 * For statistics only
118 			 */
119 			if (*status & UART_LSR_BI) {
120 				*status &= ~(UART_LSR_FE | UART_LSR_PE);
121 				up->port.icount.brk++;
122 				/*
123 				 * We do the SysRQ and SAK checking
124 				 * here because otherwise the break
125 				 * may get masked by ignore_status_mask
126 				 * or read_status_mask.
127 				 */
128 				if (uart_handle_break(&up->port))
129 					goto ignore_char;
130 			} else if (*status & UART_LSR_PE)
131 				up->port.icount.parity++;
132 			else if (*status & UART_LSR_FE)
133 				up->port.icount.frame++;
134 			if (*status & UART_LSR_OE)
135 				up->port.icount.overrun++;
136 
137 			/*
138 			 * Mask off conditions which should be ignored.
139 			 */
140 			*status &= up->port.read_status_mask;
141 
142 #ifdef CONFIG_SERIAL_PXA_CONSOLE
143 			if (up->port.line == up->port.cons->index) {
144 				/* Recover the break flag from console xmit */
145 				*status |= up->lsr_break_flag;
146 				up->lsr_break_flag = 0;
147 			}
148 #endif
149 			if (*status & UART_LSR_BI) {
150 				flag = TTY_BREAK;
151 			} else if (*status & UART_LSR_PE)
152 				flag = TTY_PARITY;
153 			else if (*status & UART_LSR_FE)
154 				flag = TTY_FRAME;
155 		}
156 
157 		if (uart_handle_sysrq_char(&up->port, ch))
158 			goto ignore_char;
159 
160 		uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
161 
162 	ignore_char:
163 		*status = serial_in(up, UART_LSR);
164 	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
165 	tty_flip_buffer_push(&up->port.state->port);
166 
167 	/* work around Errata #20 according to
168 	 * Intel(R) PXA27x Processor Family
169 	 * Specification Update (May 2005)
170 	 *
171 	 * Step 6:
172 	 * No more data in FIFO: Re-enable RTO interrupt via IER[RTOIE]
173 	 */
174 	up->ier |= UART_IER_RTOIE;
175 	serial_out(up, UART_IER, up->ier);
176 }
177 
178 static void transmit_chars(struct uart_pxa_port *up)
179 {
180 	struct circ_buf *xmit = &up->port.state->xmit;
181 	int count;
182 
183 	if (up->port.x_char) {
184 		serial_out(up, UART_TX, up->port.x_char);
185 		up->port.icount.tx++;
186 		up->port.x_char = 0;
187 		return;
188 	}
189 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
190 		serial_pxa_stop_tx(&up->port);
191 		return;
192 	}
193 
194 	count = up->port.fifosize / 2;
195 	do {
196 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
197 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
198 		up->port.icount.tx++;
199 		if (uart_circ_empty(xmit))
200 			break;
201 	} while (--count > 0);
202 
203 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
204 		uart_write_wakeup(&up->port);
205 
206 
207 	if (uart_circ_empty(xmit))
208 		serial_pxa_stop_tx(&up->port);
209 }
210 
211 static void serial_pxa_start_tx(struct uart_port *port)
212 {
213 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
214 
215 	if (!(up->ier & UART_IER_THRI)) {
216 		up->ier |= UART_IER_THRI;
217 		serial_out(up, UART_IER, up->ier);
218 	}
219 }
220 
221 /* should hold up->port.lock */
222 static inline void check_modem_status(struct uart_pxa_port *up)
223 {
224 	int status;
225 
226 	status = serial_in(up, UART_MSR);
227 
228 	if ((status & UART_MSR_ANY_DELTA) == 0)
229 		return;
230 
231 	if (status & UART_MSR_TERI)
232 		up->port.icount.rng++;
233 	if (status & UART_MSR_DDSR)
234 		up->port.icount.dsr++;
235 	if (status & UART_MSR_DDCD)
236 		uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
237 	if (status & UART_MSR_DCTS)
238 		uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
239 
240 	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
241 }
242 
243 /*
244  * This handles the interrupt from one port.
245  */
246 static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
247 {
248 	struct uart_pxa_port *up = dev_id;
249 	unsigned int iir, lsr;
250 
251 	iir = serial_in(up, UART_IIR);
252 	if (iir & UART_IIR_NO_INT)
253 		return IRQ_NONE;
254 	spin_lock(&up->port.lock);
255 	lsr = serial_in(up, UART_LSR);
256 	if (lsr & UART_LSR_DR)
257 		receive_chars(up, &lsr);
258 	check_modem_status(up);
259 	if (lsr & UART_LSR_THRE)
260 		transmit_chars(up);
261 	spin_unlock(&up->port.lock);
262 	return IRQ_HANDLED;
263 }
264 
265 static unsigned int serial_pxa_tx_empty(struct uart_port *port)
266 {
267 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
268 	unsigned long flags;
269 	unsigned int ret;
270 
271 	spin_lock_irqsave(&up->port.lock, flags);
272 	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
273 	spin_unlock_irqrestore(&up->port.lock, flags);
274 
275 	return ret;
276 }
277 
278 static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
279 {
280 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
281 	unsigned char status;
282 	unsigned int ret;
283 
284 	status = serial_in(up, UART_MSR);
285 
286 	ret = 0;
287 	if (status & UART_MSR_DCD)
288 		ret |= TIOCM_CAR;
289 	if (status & UART_MSR_RI)
290 		ret |= TIOCM_RNG;
291 	if (status & UART_MSR_DSR)
292 		ret |= TIOCM_DSR;
293 	if (status & UART_MSR_CTS)
294 		ret |= TIOCM_CTS;
295 	return ret;
296 }
297 
298 static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
299 {
300 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
301 	unsigned char mcr = 0;
302 
303 	if (mctrl & TIOCM_RTS)
304 		mcr |= UART_MCR_RTS;
305 	if (mctrl & TIOCM_DTR)
306 		mcr |= UART_MCR_DTR;
307 	if (mctrl & TIOCM_OUT1)
308 		mcr |= UART_MCR_OUT1;
309 	if (mctrl & TIOCM_OUT2)
310 		mcr |= UART_MCR_OUT2;
311 	if (mctrl & TIOCM_LOOP)
312 		mcr |= UART_MCR_LOOP;
313 
314 	mcr |= up->mcr;
315 
316 	serial_out(up, UART_MCR, mcr);
317 }
318 
319 static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
320 {
321 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
322 	unsigned long flags;
323 
324 	spin_lock_irqsave(&up->port.lock, flags);
325 	if (break_state == -1)
326 		up->lcr |= UART_LCR_SBC;
327 	else
328 		up->lcr &= ~UART_LCR_SBC;
329 	serial_out(up, UART_LCR, up->lcr);
330 	spin_unlock_irqrestore(&up->port.lock, flags);
331 }
332 
333 static int serial_pxa_startup(struct uart_port *port)
334 {
335 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
336 	unsigned long flags;
337 	int retval;
338 
339 	if (port->line == 3) /* HWUART */
340 		up->mcr |= UART_MCR_AFE;
341 	else
342 		up->mcr = 0;
343 
344 	up->port.uartclk = clk_get_rate(up->clk);
345 
346 	/*
347 	 * Allocate the IRQ
348 	 */
349 	retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
350 	if (retval)
351 		return retval;
352 
353 	/*
354 	 * Clear the FIFO buffers and disable them.
355 	 * (they will be reenabled in set_termios())
356 	 */
357 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
358 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
359 			UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
360 	serial_out(up, UART_FCR, 0);
361 
362 	/*
363 	 * Clear the interrupt registers.
364 	 */
365 	(void) serial_in(up, UART_LSR);
366 	(void) serial_in(up, UART_RX);
367 	(void) serial_in(up, UART_IIR);
368 	(void) serial_in(up, UART_MSR);
369 
370 	/*
371 	 * Now, initialize the UART
372 	 */
373 	serial_out(up, UART_LCR, UART_LCR_WLEN8);
374 
375 	spin_lock_irqsave(&up->port.lock, flags);
376 	up->port.mctrl |= TIOCM_OUT2;
377 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
378 	spin_unlock_irqrestore(&up->port.lock, flags);
379 
380 	/*
381 	 * Finally, enable interrupts.  Note: Modem status interrupts
382 	 * are set via set_termios(), which will be occurring imminently
383 	 * anyway, so we don't enable them here.
384 	 */
385 	up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
386 	serial_out(up, UART_IER, up->ier);
387 
388 	/*
389 	 * And clear the interrupt registers again for luck.
390 	 */
391 	(void) serial_in(up, UART_LSR);
392 	(void) serial_in(up, UART_RX);
393 	(void) serial_in(up, UART_IIR);
394 	(void) serial_in(up, UART_MSR);
395 
396 	return 0;
397 }
398 
399 static void serial_pxa_shutdown(struct uart_port *port)
400 {
401 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
402 	unsigned long flags;
403 
404 	free_irq(up->port.irq, up);
405 
406 	/*
407 	 * Disable interrupts from this port
408 	 */
409 	up->ier = 0;
410 	serial_out(up, UART_IER, 0);
411 
412 	spin_lock_irqsave(&up->port.lock, flags);
413 	up->port.mctrl &= ~TIOCM_OUT2;
414 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
415 	spin_unlock_irqrestore(&up->port.lock, flags);
416 
417 	/*
418 	 * Disable break condition and FIFOs
419 	 */
420 	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
421 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
422 				  UART_FCR_CLEAR_RCVR |
423 				  UART_FCR_CLEAR_XMIT);
424 	serial_out(up, UART_FCR, 0);
425 }
426 
427 static void
428 serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
429 		       struct ktermios *old)
430 {
431 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
432 	unsigned char cval, fcr = 0;
433 	unsigned long flags;
434 	unsigned int baud, quot;
435 	unsigned int dll;
436 
437 	switch (termios->c_cflag & CSIZE) {
438 	case CS5:
439 		cval = UART_LCR_WLEN5;
440 		break;
441 	case CS6:
442 		cval = UART_LCR_WLEN6;
443 		break;
444 	case CS7:
445 		cval = UART_LCR_WLEN7;
446 		break;
447 	default:
448 	case CS8:
449 		cval = UART_LCR_WLEN8;
450 		break;
451 	}
452 
453 	if (termios->c_cflag & CSTOPB)
454 		cval |= UART_LCR_STOP;
455 	if (termios->c_cflag & PARENB)
456 		cval |= UART_LCR_PARITY;
457 	if (!(termios->c_cflag & PARODD))
458 		cval |= UART_LCR_EPAR;
459 
460 	/*
461 	 * Ask the core to calculate the divisor for us.
462 	 */
463 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
464 	quot = uart_get_divisor(port, baud);
465 
466 	if ((up->port.uartclk / quot) < (2400 * 16))
467 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
468 	else if ((up->port.uartclk / quot) < (230400 * 16))
469 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
470 	else
471 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
472 
473 	/*
474 	 * Ok, we're now changing the port state.  Do it with
475 	 * interrupts disabled.
476 	 */
477 	spin_lock_irqsave(&up->port.lock, flags);
478 
479 	/*
480 	 * Ensure the port will be enabled.
481 	 * This is required especially for serial console.
482 	 */
483 	up->ier |= UART_IER_UUE;
484 
485 	/*
486 	 * Update the per-port timeout.
487 	 */
488 	uart_update_timeout(port, termios->c_cflag, baud);
489 
490 	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
491 	if (termios->c_iflag & INPCK)
492 		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
493 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
494 		up->port.read_status_mask |= UART_LSR_BI;
495 
496 	/*
497 	 * Characters to ignore
498 	 */
499 	up->port.ignore_status_mask = 0;
500 	if (termios->c_iflag & IGNPAR)
501 		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
502 	if (termios->c_iflag & IGNBRK) {
503 		up->port.ignore_status_mask |= UART_LSR_BI;
504 		/*
505 		 * If we're ignoring parity and break indicators,
506 		 * ignore overruns too (for real raw support).
507 		 */
508 		if (termios->c_iflag & IGNPAR)
509 			up->port.ignore_status_mask |= UART_LSR_OE;
510 	}
511 
512 	/*
513 	 * ignore all characters if CREAD is not set
514 	 */
515 	if ((termios->c_cflag & CREAD) == 0)
516 		up->port.ignore_status_mask |= UART_LSR_DR;
517 
518 	/*
519 	 * CTS flow control flag and modem status interrupts
520 	 */
521 	up->ier &= ~UART_IER_MSI;
522 	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
523 		up->ier |= UART_IER_MSI;
524 
525 	serial_out(up, UART_IER, up->ier);
526 
527 	if (termios->c_cflag & CRTSCTS)
528 		up->mcr |= UART_MCR_AFE;
529 	else
530 		up->mcr &= ~UART_MCR_AFE;
531 
532 	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);	/* set DLAB */
533 	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
534 
535 	/*
536 	 * work around Errata #75 according to Intel(R) PXA27x Processor Family
537 	 * Specification Update (Nov 2005)
538 	 */
539 	dll = serial_in(up, UART_DLL);
540 	WARN_ON(dll != (quot & 0xff));
541 
542 	serial_out(up, UART_DLM, quot >> 8);		/* MS of divisor */
543 	serial_out(up, UART_LCR, cval);			/* reset DLAB */
544 	up->lcr = cval;					/* Save LCR */
545 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
546 	serial_out(up, UART_FCR, fcr);
547 	spin_unlock_irqrestore(&up->port.lock, flags);
548 }
549 
550 static void
551 serial_pxa_pm(struct uart_port *port, unsigned int state,
552 	      unsigned int oldstate)
553 {
554 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
555 
556 	if (!state)
557 		clk_prepare_enable(up->clk);
558 	else
559 		clk_disable_unprepare(up->clk);
560 }
561 
562 static void serial_pxa_release_port(struct uart_port *port)
563 {
564 }
565 
566 static int serial_pxa_request_port(struct uart_port *port)
567 {
568 	return 0;
569 }
570 
571 static void serial_pxa_config_port(struct uart_port *port, int flags)
572 {
573 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
574 	up->port.type = PORT_PXA;
575 }
576 
577 static int
578 serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
579 {
580 	/* we don't want the core code to modify any port params */
581 	return -EINVAL;
582 }
583 
584 static const char *
585 serial_pxa_type(struct uart_port *port)
586 {
587 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
588 	return up->name;
589 }
590 
591 static struct uart_pxa_port *serial_pxa_ports[4];
592 static struct uart_driver serial_pxa_reg;
593 
594 #ifdef CONFIG_SERIAL_PXA_CONSOLE
595 
596 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
597 
598 /*
599  *	Wait for transmitter & holding register to empty
600  */
601 static void wait_for_xmitr(struct uart_pxa_port *up)
602 {
603 	unsigned int status, tmout = 10000;
604 
605 	/* Wait up to 10ms for the character(s) to be sent. */
606 	do {
607 		status = serial_in(up, UART_LSR);
608 
609 		if (status & UART_LSR_BI)
610 			up->lsr_break_flag = UART_LSR_BI;
611 
612 		if (--tmout == 0)
613 			break;
614 		udelay(1);
615 	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
616 
617 	/* Wait up to 1s for flow control if necessary */
618 	if (up->port.flags & UPF_CONS_FLOW) {
619 		tmout = 1000000;
620 		while (--tmout &&
621 		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
622 			udelay(1);
623 	}
624 }
625 
626 static void serial_pxa_console_putchar(struct uart_port *port, int ch)
627 {
628 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
629 
630 	wait_for_xmitr(up);
631 	serial_out(up, UART_TX, ch);
632 }
633 
634 /*
635  * Print a string to the serial port trying not to disturb
636  * any possible real use of the port...
637  *
638  *	The console_lock must be held when we get here.
639  */
640 static void
641 serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
642 {
643 	struct uart_pxa_port *up = serial_pxa_ports[co->index];
644 	unsigned int ier;
645 	unsigned long flags;
646 	int locked = 1;
647 
648 	clk_enable(up->clk);
649 	local_irq_save(flags);
650 	if (up->port.sysrq)
651 		locked = 0;
652 	else if (oops_in_progress)
653 		locked = spin_trylock(&up->port.lock);
654 	else
655 		spin_lock(&up->port.lock);
656 
657 	/*
658 	 *	First save the IER then disable the interrupts
659 	 */
660 	ier = serial_in(up, UART_IER);
661 	serial_out(up, UART_IER, UART_IER_UUE);
662 
663 	uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
664 
665 	/*
666 	 *	Finally, wait for transmitter to become empty
667 	 *	and restore the IER
668 	 */
669 	wait_for_xmitr(up);
670 	serial_out(up, UART_IER, ier);
671 
672 	if (locked)
673 		spin_unlock(&up->port.lock);
674 	local_irq_restore(flags);
675 	clk_disable(up->clk);
676 
677 }
678 
679 #ifdef CONFIG_CONSOLE_POLL
680 /*
681  * Console polling routines for writing and reading from the uart while
682  * in an interrupt or debug context.
683  */
684 
685 static int serial_pxa_get_poll_char(struct uart_port *port)
686 {
687 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
688 	unsigned char lsr = serial_in(up, UART_LSR);
689 
690 	while (!(lsr & UART_LSR_DR))
691 		lsr = serial_in(up, UART_LSR);
692 
693 	return serial_in(up, UART_RX);
694 }
695 
696 
697 static void serial_pxa_put_poll_char(struct uart_port *port,
698 			 unsigned char c)
699 {
700 	unsigned int ier;
701 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
702 
703 	/*
704 	 *	First save the IER then disable the interrupts
705 	 */
706 	ier = serial_in(up, UART_IER);
707 	serial_out(up, UART_IER, UART_IER_UUE);
708 
709 	wait_for_xmitr(up);
710 	/*
711 	 *	Send the character out.
712 	 */
713 	serial_out(up, UART_TX, c);
714 
715 	/*
716 	 *	Finally, wait for transmitter to become empty
717 	 *	and restore the IER
718 	 */
719 	wait_for_xmitr(up);
720 	serial_out(up, UART_IER, ier);
721 }
722 
723 #endif /* CONFIG_CONSOLE_POLL */
724 
725 static int __init
726 serial_pxa_console_setup(struct console *co, char *options)
727 {
728 	struct uart_pxa_port *up;
729 	int baud = 9600;
730 	int bits = 8;
731 	int parity = 'n';
732 	int flow = 'n';
733 
734 	if (co->index == -1 || co->index >= serial_pxa_reg.nr)
735 		co->index = 0;
736 	up = serial_pxa_ports[co->index];
737 	if (!up)
738 		return -ENODEV;
739 
740 	if (options)
741 		uart_parse_options(options, &baud, &parity, &bits, &flow);
742 
743 	return uart_set_options(&up->port, co, baud, parity, bits, flow);
744 }
745 
746 static struct console serial_pxa_console = {
747 	.name		= "ttyS",
748 	.write		= serial_pxa_console_write,
749 	.device		= uart_console_device,
750 	.setup		= serial_pxa_console_setup,
751 	.flags		= CON_PRINTBUFFER,
752 	.index		= -1,
753 	.data		= &serial_pxa_reg,
754 };
755 
756 #define PXA_CONSOLE	&serial_pxa_console
757 #else
758 #define PXA_CONSOLE	NULL
759 #endif
760 
761 static const struct uart_ops serial_pxa_pops = {
762 	.tx_empty	= serial_pxa_tx_empty,
763 	.set_mctrl	= serial_pxa_set_mctrl,
764 	.get_mctrl	= serial_pxa_get_mctrl,
765 	.stop_tx	= serial_pxa_stop_tx,
766 	.start_tx	= serial_pxa_start_tx,
767 	.stop_rx	= serial_pxa_stop_rx,
768 	.enable_ms	= serial_pxa_enable_ms,
769 	.break_ctl	= serial_pxa_break_ctl,
770 	.startup	= serial_pxa_startup,
771 	.shutdown	= serial_pxa_shutdown,
772 	.set_termios	= serial_pxa_set_termios,
773 	.pm		= serial_pxa_pm,
774 	.type		= serial_pxa_type,
775 	.release_port	= serial_pxa_release_port,
776 	.request_port	= serial_pxa_request_port,
777 	.config_port	= serial_pxa_config_port,
778 	.verify_port	= serial_pxa_verify_port,
779 #if defined(CONFIG_CONSOLE_POLL) && defined(CONFIG_SERIAL_PXA_CONSOLE)
780 	.poll_get_char = serial_pxa_get_poll_char,
781 	.poll_put_char = serial_pxa_put_poll_char,
782 #endif
783 };
784 
785 static struct uart_driver serial_pxa_reg = {
786 	.owner		= THIS_MODULE,
787 	.driver_name	= "PXA serial",
788 	.dev_name	= "ttyS",
789 	.major		= TTY_MAJOR,
790 	.minor		= 64,
791 	.nr		= 4,
792 	.cons		= PXA_CONSOLE,
793 };
794 
795 #ifdef CONFIG_PM
796 static int serial_pxa_suspend(struct device *dev)
797 {
798         struct uart_pxa_port *sport = dev_get_drvdata(dev);
799 
800         if (sport)
801                 uart_suspend_port(&serial_pxa_reg, &sport->port);
802 
803         return 0;
804 }
805 
806 static int serial_pxa_resume(struct device *dev)
807 {
808         struct uart_pxa_port *sport = dev_get_drvdata(dev);
809 
810         if (sport)
811                 uart_resume_port(&serial_pxa_reg, &sport->port);
812 
813         return 0;
814 }
815 
816 static const struct dev_pm_ops serial_pxa_pm_ops = {
817 	.suspend	= serial_pxa_suspend,
818 	.resume		= serial_pxa_resume,
819 };
820 #endif
821 
822 static const struct of_device_id serial_pxa_dt_ids[] = {
823 	{ .compatible = "mrvl,pxa-uart", },
824 	{ .compatible = "mrvl,mmp-uart", },
825 	{}
826 };
827 
828 static int serial_pxa_probe_dt(struct platform_device *pdev,
829 			       struct uart_pxa_port *sport)
830 {
831 	struct device_node *np = pdev->dev.of_node;
832 	int ret;
833 
834 	if (!np)
835 		return 1;
836 
837 	ret = of_alias_get_id(np, "serial");
838 	if (ret < 0) {
839 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
840 		return ret;
841 	}
842 	sport->port.line = ret;
843 	return 0;
844 }
845 
846 static int serial_pxa_probe(struct platform_device *dev)
847 {
848 	struct uart_pxa_port *sport;
849 	struct resource *mmres, *irqres;
850 	int ret;
851 
852 	mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
853 	irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
854 	if (!mmres || !irqres)
855 		return -ENODEV;
856 
857 	sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
858 	if (!sport)
859 		return -ENOMEM;
860 
861 	sport->clk = clk_get(&dev->dev, NULL);
862 	if (IS_ERR(sport->clk)) {
863 		ret = PTR_ERR(sport->clk);
864 		goto err_free;
865 	}
866 
867 	ret = clk_prepare(sport->clk);
868 	if (ret) {
869 		clk_put(sport->clk);
870 		goto err_free;
871 	}
872 
873 	sport->port.type = PORT_PXA;
874 	sport->port.iotype = UPIO_MEM;
875 	sport->port.mapbase = mmres->start;
876 	sport->port.irq = irqres->start;
877 	sport->port.fifosize = 64;
878 	sport->port.ops = &serial_pxa_pops;
879 	sport->port.dev = &dev->dev;
880 	sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
881 	sport->port.uartclk = clk_get_rate(sport->clk);
882 
883 	ret = serial_pxa_probe_dt(dev, sport);
884 	if (ret > 0)
885 		sport->port.line = dev->id;
886 	else if (ret < 0)
887 		goto err_clk;
888 	if (sport->port.line >= ARRAY_SIZE(serial_pxa_ports)) {
889 		dev_err(&dev->dev, "serial%d out of range\n", sport->port.line);
890 		return -EINVAL;
891 	}
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