xref: /linux/drivers/tty/serial/pxa.c (revision 148f9bb87745ed45f7a11b2cbd3bc0f017d5d257)
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 #if 0
336 static void serial_pxa_dma_init(struct pxa_uart *up)
337 {
338 	up->rxdma =
339 		pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_receive_dma, up);
340 	if (up->rxdma < 0)
341 		goto out;
342 	up->txdma =
343 		pxa_request_dma(up->name, DMA_PRIO_LOW, pxa_transmit_dma, up);
344 	if (up->txdma < 0)
345 		goto err_txdma;
346 	up->dmadesc = kmalloc(4 * sizeof(pxa_dma_desc), GFP_KERNEL);
347 	if (!up->dmadesc)
348 		goto err_alloc;
349 
350 	/* ... */
351 err_alloc:
352 	pxa_free_dma(up->txdma);
353 err_rxdma:
354 	pxa_free_dma(up->rxdma);
355 out:
356 	return;
357 }
358 #endif
359 
360 static int serial_pxa_startup(struct uart_port *port)
361 {
362 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
363 	unsigned long flags;
364 	int retval;
365 
366 	if (port->line == 3) /* HWUART */
367 		up->mcr |= UART_MCR_AFE;
368 	else
369 		up->mcr = 0;
370 
371 	up->port.uartclk = clk_get_rate(up->clk);
372 
373 	/*
374 	 * Allocate the IRQ
375 	 */
376 	retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
377 	if (retval)
378 		return retval;
379 
380 	/*
381 	 * Clear the FIFO buffers and disable them.
382 	 * (they will be reenabled in set_termios())
383 	 */
384 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
385 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
386 			UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
387 	serial_out(up, UART_FCR, 0);
388 
389 	/*
390 	 * Clear the interrupt registers.
391 	 */
392 	(void) serial_in(up, UART_LSR);
393 	(void) serial_in(up, UART_RX);
394 	(void) serial_in(up, UART_IIR);
395 	(void) serial_in(up, UART_MSR);
396 
397 	/*
398 	 * Now, initialize the UART
399 	 */
400 	serial_out(up, UART_LCR, UART_LCR_WLEN8);
401 
402 	spin_lock_irqsave(&up->port.lock, flags);
403 	up->port.mctrl |= TIOCM_OUT2;
404 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
405 	spin_unlock_irqrestore(&up->port.lock, flags);
406 
407 	/*
408 	 * Finally, enable interrupts.  Note: Modem status interrupts
409 	 * are set via set_termios(), which will be occurring imminently
410 	 * anyway, so we don't enable them here.
411 	 */
412 	up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
413 	serial_out(up, UART_IER, up->ier);
414 
415 	/*
416 	 * And clear the interrupt registers again for luck.
417 	 */
418 	(void) serial_in(up, UART_LSR);
419 	(void) serial_in(up, UART_RX);
420 	(void) serial_in(up, UART_IIR);
421 	(void) serial_in(up, UART_MSR);
422 
423 	return 0;
424 }
425 
426 static void serial_pxa_shutdown(struct uart_port *port)
427 {
428 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
429 	unsigned long flags;
430 
431 	free_irq(up->port.irq, up);
432 
433 	/*
434 	 * Disable interrupts from this port
435 	 */
436 	up->ier = 0;
437 	serial_out(up, UART_IER, 0);
438 
439 	spin_lock_irqsave(&up->port.lock, flags);
440 	up->port.mctrl &= ~TIOCM_OUT2;
441 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
442 	spin_unlock_irqrestore(&up->port.lock, flags);
443 
444 	/*
445 	 * Disable break condition and FIFOs
446 	 */
447 	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
448 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
449 				  UART_FCR_CLEAR_RCVR |
450 				  UART_FCR_CLEAR_XMIT);
451 	serial_out(up, UART_FCR, 0);
452 }
453 
454 static void
455 serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
456 		       struct ktermios *old)
457 {
458 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
459 	unsigned char cval, fcr = 0;
460 	unsigned long flags;
461 	unsigned int baud, quot;
462 	unsigned int dll;
463 
464 	switch (termios->c_cflag & CSIZE) {
465 	case CS5:
466 		cval = UART_LCR_WLEN5;
467 		break;
468 	case CS6:
469 		cval = UART_LCR_WLEN6;
470 		break;
471 	case CS7:
472 		cval = UART_LCR_WLEN7;
473 		break;
474 	default:
475 	case CS8:
476 		cval = UART_LCR_WLEN8;
477 		break;
478 	}
479 
480 	if (termios->c_cflag & CSTOPB)
481 		cval |= UART_LCR_STOP;
482 	if (termios->c_cflag & PARENB)
483 		cval |= UART_LCR_PARITY;
484 	if (!(termios->c_cflag & PARODD))
485 		cval |= UART_LCR_EPAR;
486 
487 	/*
488 	 * Ask the core to calculate the divisor for us.
489 	 */
490 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
491 	quot = uart_get_divisor(port, baud);
492 
493 	if ((up->port.uartclk / quot) < (2400 * 16))
494 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
495 	else if ((up->port.uartclk / quot) < (230400 * 16))
496 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
497 	else
498 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
499 
500 	/*
501 	 * Ok, we're now changing the port state.  Do it with
502 	 * interrupts disabled.
503 	 */
504 	spin_lock_irqsave(&up->port.lock, flags);
505 
506 	/*
507 	 * Ensure the port will be enabled.
508 	 * This is required especially for serial console.
509 	 */
510 	up->ier |= UART_IER_UUE;
511 
512 	/*
513 	 * Update the per-port timeout.
514 	 */
515 	uart_update_timeout(port, termios->c_cflag, baud);
516 
517 	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
518 	if (termios->c_iflag & INPCK)
519 		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
520 	if (termios->c_iflag & (BRKINT | PARMRK))
521 		up->port.read_status_mask |= UART_LSR_BI;
522 
523 	/*
524 	 * Characters to ignore
525 	 */
526 	up->port.ignore_status_mask = 0;
527 	if (termios->c_iflag & IGNPAR)
528 		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
529 	if (termios->c_iflag & IGNBRK) {
530 		up->port.ignore_status_mask |= UART_LSR_BI;
531 		/*
532 		 * If we're ignoring parity and break indicators,
533 		 * ignore overruns too (for real raw support).
534 		 */
535 		if (termios->c_iflag & IGNPAR)
536 			up->port.ignore_status_mask |= UART_LSR_OE;
537 	}
538 
539 	/*
540 	 * ignore all characters if CREAD is not set
541 	 */
542 	if ((termios->c_cflag & CREAD) == 0)
543 		up->port.ignore_status_mask |= UART_LSR_DR;
544 
545 	/*
546 	 * CTS flow control flag and modem status interrupts
547 	 */
548 	up->ier &= ~UART_IER_MSI;
549 	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
550 		up->ier |= UART_IER_MSI;
551 
552 	serial_out(up, UART_IER, up->ier);
553 
554 	if (termios->c_cflag & CRTSCTS)
555 		up->mcr |= UART_MCR_AFE;
556 	else
557 		up->mcr &= ~UART_MCR_AFE;
558 
559 	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);	/* set DLAB */
560 	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
561 
562 	/*
563 	 * work around Errata #75 according to Intel(R) PXA27x Processor Family
564 	 * Specification Update (Nov 2005)
565 	 */
566 	dll = serial_in(up, UART_DLL);
567 	WARN_ON(dll != (quot & 0xff));
568 
569 	serial_out(up, UART_DLM, quot >> 8);		/* MS of divisor */
570 	serial_out(up, UART_LCR, cval);			/* reset DLAB */
571 	up->lcr = cval;					/* Save LCR */
572 	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
573 	serial_out(up, UART_FCR, fcr);
574 	spin_unlock_irqrestore(&up->port.lock, flags);
575 }
576 
577 static void
578 serial_pxa_pm(struct uart_port *port, unsigned int state,
579 	      unsigned int oldstate)
580 {
581 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
582 
583 	if (!state)
584 		clk_prepare_enable(up->clk);
585 	else
586 		clk_disable_unprepare(up->clk);
587 }
588 
589 static void serial_pxa_release_port(struct uart_port *port)
590 {
591 }
592 
593 static int serial_pxa_request_port(struct uart_port *port)
594 {
595 	return 0;
596 }
597 
598 static void serial_pxa_config_port(struct uart_port *port, int flags)
599 {
600 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
601 	up->port.type = PORT_PXA;
602 }
603 
604 static int
605 serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
606 {
607 	/* we don't want the core code to modify any port params */
608 	return -EINVAL;
609 }
610 
611 static const char *
612 serial_pxa_type(struct uart_port *port)
613 {
614 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
615 	return up->name;
616 }
617 
618 static struct uart_pxa_port *serial_pxa_ports[4];
619 static struct uart_driver serial_pxa_reg;
620 
621 #ifdef CONFIG_SERIAL_PXA_CONSOLE
622 
623 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
624 
625 /*
626  *	Wait for transmitter & holding register to empty
627  */
628 static inline void wait_for_xmitr(struct uart_pxa_port *up)
629 {
630 	unsigned int status, tmout = 10000;
631 
632 	/* Wait up to 10ms for the character(s) to be sent. */
633 	do {
634 		status = serial_in(up, UART_LSR);
635 
636 		if (status & UART_LSR_BI)
637 			up->lsr_break_flag = UART_LSR_BI;
638 
639 		if (--tmout == 0)
640 			break;
641 		udelay(1);
642 	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
643 
644 	/* Wait up to 1s for flow control if necessary */
645 	if (up->port.flags & UPF_CONS_FLOW) {
646 		tmout = 1000000;
647 		while (--tmout &&
648 		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
649 			udelay(1);
650 	}
651 }
652 
653 static void serial_pxa_console_putchar(struct uart_port *port, int ch)
654 {
655 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
656 
657 	wait_for_xmitr(up);
658 	serial_out(up, UART_TX, ch);
659 }
660 
661 /*
662  * Print a string to the serial port trying not to disturb
663  * any possible real use of the port...
664  *
665  *	The console_lock must be held when we get here.
666  */
667 static void
668 serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
669 {
670 	struct uart_pxa_port *up = serial_pxa_ports[co->index];
671 	unsigned int ier;
672 	unsigned long flags;
673 	int locked = 1;
674 
675 	clk_enable(up->clk);
676 	local_irq_save(flags);
677 	if (up->port.sysrq)
678 		locked = 0;
679 	else if (oops_in_progress)
680 		locked = spin_trylock(&up->port.lock);
681 	else
682 		spin_lock(&up->port.lock);
683 
684 	/*
685 	 *	First save the IER then disable the interrupts
686 	 */
687 	ier = serial_in(up, UART_IER);
688 	serial_out(up, UART_IER, UART_IER_UUE);
689 
690 	uart_console_write(&up->port, s, count, serial_pxa_console_putchar);
691 
692 	/*
693 	 *	Finally, wait for transmitter to become empty
694 	 *	and restore the IER
695 	 */
696 	wait_for_xmitr(up);
697 	serial_out(up, UART_IER, ier);
698 
699 	if (locked)
700 		spin_unlock(&up->port.lock);
701 	local_irq_restore(flags);
702 	clk_disable(up->clk);
703 
704 }
705 
706 #ifdef CONFIG_CONSOLE_POLL
707 /*
708  * Console polling routines for writing and reading from the uart while
709  * in an interrupt or debug context.
710  */
711 
712 static int serial_pxa_get_poll_char(struct uart_port *port)
713 {
714 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
715 	unsigned char lsr = serial_in(up, UART_LSR);
716 
717 	while (!(lsr & UART_LSR_DR))
718 		lsr = serial_in(up, UART_LSR);
719 
720 	return serial_in(up, UART_RX);
721 }
722 
723 
724 static void serial_pxa_put_poll_char(struct uart_port *port,
725 			 unsigned char c)
726 {
727 	unsigned int ier;
728 	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
729 
730 	/*
731 	 *	First save the IER then disable the interrupts
732 	 */
733 	ier = serial_in(up, UART_IER);
734 	serial_out(up, UART_IER, UART_IER_UUE);
735 
736 	wait_for_xmitr(up);
737 	/*
738 	 *	Send the character out.
739 	 *	If a LF, also do CR...
740 	 */
741 	serial_out(up, UART_TX, c);
742 	if (c == 10) {
743 		wait_for_xmitr(up);
744 		serial_out(up, UART_TX, 13);
745 	}
746 
747 	/*
748 	 *	Finally, wait for transmitter to become empty
749 	 *	and restore the IER
750 	 */
751 	wait_for_xmitr(up);
752 	serial_out(up, UART_IER, ier);
753 }
754 
755 #endif /* CONFIG_CONSOLE_POLL */
756 
757 static int __init
758 serial_pxa_console_setup(struct console *co, char *options)
759 {
760 	struct uart_pxa_port *up;
761 	int baud = 9600;
762 	int bits = 8;
763 	int parity = 'n';
764 	int flow = 'n';
765 
766 	if (co->index == -1 || co->index >= serial_pxa_reg.nr)
767 		co->index = 0;
768 	up = serial_pxa_ports[co->index];
769 	if (!up)
770 		return -ENODEV;
771 
772 	if (options)
773 		uart_parse_options(options, &baud, &parity, &bits, &flow);
774 
775 	return uart_set_options(&up->port, co, baud, parity, bits, flow);
776 }
777 
778 static struct console serial_pxa_console = {
779 	.name		= "ttyS",
780 	.write		= serial_pxa_console_write,
781 	.device		= uart_console_device,
782 	.setup		= serial_pxa_console_setup,
783 	.flags		= CON_PRINTBUFFER,
784 	.index		= -1,
785 	.data		= &serial_pxa_reg,
786 };
787 
788 #define PXA_CONSOLE	&serial_pxa_console
789 #else
790 #define PXA_CONSOLE	NULL
791 #endif
792 
793 struct uart_ops serial_pxa_pops = {
794 	.tx_empty	= serial_pxa_tx_empty,
795 	.set_mctrl	= serial_pxa_set_mctrl,
796 	.get_mctrl	= serial_pxa_get_mctrl,
797 	.stop_tx	= serial_pxa_stop_tx,
798 	.start_tx	= serial_pxa_start_tx,
799 	.stop_rx	= serial_pxa_stop_rx,
800 	.enable_ms	= serial_pxa_enable_ms,
801 	.break_ctl	= serial_pxa_break_ctl,
802 	.startup	= serial_pxa_startup,
803 	.shutdown	= serial_pxa_shutdown,
804 	.set_termios	= serial_pxa_set_termios,
805 	.pm		= serial_pxa_pm,
806 	.type		= serial_pxa_type,
807 	.release_port	= serial_pxa_release_port,
808 	.request_port	= serial_pxa_request_port,
809 	.config_port	= serial_pxa_config_port,
810 	.verify_port	= serial_pxa_verify_port,
811 #ifdef CONFIG_CONSOLE_POLL
812 	.poll_get_char = serial_pxa_get_poll_char,
813 	.poll_put_char = serial_pxa_put_poll_char,
814 #endif
815 };
816 
817 static struct uart_driver serial_pxa_reg = {
818 	.owner		= THIS_MODULE,
819 	.driver_name	= "PXA serial",
820 	.dev_name	= "ttyS",
821 	.major		= TTY_MAJOR,
822 	.minor		= 64,
823 	.nr		= 4,
824 	.cons		= PXA_CONSOLE,
825 };
826 
827 #ifdef CONFIG_PM
828 static int serial_pxa_suspend(struct device *dev)
829 {
830         struct uart_pxa_port *sport = dev_get_drvdata(dev);
831 
832         if (sport)
833                 uart_suspend_port(&serial_pxa_reg, &sport->port);
834 
835         return 0;
836 }
837 
838 static int serial_pxa_resume(struct device *dev)
839 {
840         struct uart_pxa_port *sport = dev_get_drvdata(dev);
841 
842         if (sport)
843                 uart_resume_port(&serial_pxa_reg, &sport->port);
844 
845         return 0;
846 }
847 
848 static const struct dev_pm_ops serial_pxa_pm_ops = {
849 	.suspend	= serial_pxa_suspend,
850 	.resume		= serial_pxa_resume,
851 };
852 #endif
853 
854 static struct of_device_id serial_pxa_dt_ids[] = {
855 	{ .compatible = "mrvl,pxa-uart", },
856 	{ .compatible = "mrvl,mmp-uart", },
857 	{}
858 };
859 MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
860 
861 static int serial_pxa_probe_dt(struct platform_device *pdev,
862 			       struct uart_pxa_port *sport)
863 {
864 	struct device_node *np = pdev->dev.of_node;
865 	int ret;
866 
867 	if (!np)
868 		return 1;
869 
870 	ret = of_alias_get_id(np, "serial");
871 	if (ret < 0) {
872 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
873 		return ret;
874 	}
875 	sport->port.line = ret;
876 	return 0;
877 }
878 
879 static int serial_pxa_probe(struct platform_device *dev)
880 {
881 	struct uart_pxa_port *sport;
882 	struct resource *mmres, *irqres;
883 	int ret;
884 
885 	mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
886 	irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
887 	if (!mmres || !irqres)
888 		return -ENODEV;
889 
890 	sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
891 	if (!sport)
892 		return -ENOMEM;
893 
894 	sport->clk = clk_get(&dev->dev, NULL);
895 	if (IS_ERR(sport->clk)) {
896 		ret = PTR_ERR(sport->clk);
897 		goto err_free;
898 	}
899 
900 	ret = clk_prepare(sport->clk);
901 	if (ret) {
902 		clk_put(sport->clk);
903 		goto err_free;
904 	}
905 
906 	sport->port.type = PORT_PXA;
907 	sport->port.iotype = UPIO_MEM;
908 	sport->port.mapbase = mmres->start;
909 	sport->port.irq = irqres->start;
910 	sport->port.fifosize = 64;
911 	sport->port.ops = &serial_pxa_pops;
912 	sport->port.dev = &dev->dev;
913 	sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
914 	sport->port.uartclk = clk_get_rate(sport->clk);
915 
916 	ret = serial_pxa_probe_dt(dev, sport);
917 	if (ret > 0)
918 		sport->port.line = dev->id;
919 	else if (ret < 0)
920 		goto err_clk;
921 	snprintf(sport->name, PXA_NAME_LEN - 1, "UART%d", sport->port.line + 1);
922 
923 	sport->port.membase = ioremap(mmres->start, resource_size(mmres));
924 	if (!sport->port.membase) {
925 		ret = -ENOMEM;
926 		goto err_clk;
927 	}
928 
929 	serial_pxa_ports[sport->port.line] = sport;
930 
931 	uart_add_one_port(&serial_pxa_reg, &sport->port);
932 	platform_set_drvdata(dev, sport);
933 
934 	return 0;
935 
936  err_clk:
937 	clk_unprepare(sport->clk);
938 	clk_put(sport->clk);
939  err_free:
940 	kfree(sport);
941 	return ret;
942 }
943 
944 static int serial_pxa_remove(struct platform_device *dev)
945 {
946 	struct uart_pxa_port *sport = platform_get_drvdata(dev);
947 
948 	platform_set_drvdata(dev, NULL);
949 
950 	uart_remove_one_port(&serial_pxa_reg, &sport->port);
951 
952 	clk_unprepare(sport->clk);
953 	clk_put(sport->clk);
954 	kfree(sport);
955 
956 	return 0;
957 }
958 
959 static struct platform_driver serial_pxa_driver = {
960         .probe          = serial_pxa_probe,
961         .remove         = serial_pxa_remove,
962 
963 	.driver		= {
964 	        .name	= "pxa2xx-uart",
965 		.owner	= THIS_MODULE,
966 #ifdef CONFIG_PM
967 		.pm	= &serial_pxa_pm_ops,
968 #endif
969 		.of_match_table = serial_pxa_dt_ids,
970 	},
971 };
972 
973 int __init serial_pxa_init(void)
974 {
975 	int ret;
976 
977 	ret = uart_register_driver(&serial_pxa_reg);
978 	if (ret != 0)
979 		return ret;
980 
981 	ret = platform_driver_register(&serial_pxa_driver);
982 	if (ret != 0)
983 		uart_unregister_driver(&serial_pxa_reg);
984 
985 	return ret;
986 }
987 
988 void __exit serial_pxa_exit(void)
989 {
990 	platform_driver_unregister(&serial_pxa_driver);
991 	uart_unregister_driver(&serial_pxa_reg);
992 }
993 
994 module_init(serial_pxa_init);
995 module_exit(serial_pxa_exit);
996 
997 MODULE_LICENSE("GPL");
998 MODULE_ALIAS("platform:pxa2xx-uart");
999