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