1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Freescale LINFlexD UART serial port driver
4 *
5 * Copyright 2012-2016 Freescale Semiconductor, Inc.
6 * Copyright 2017-2019 NXP
7 */
8
9#include <linux/console.h>
10#include <linux/io.h>
11#include <linux/irq.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/platform_device.h>
15#include <linux/serial_core.h>
16#include <linux/slab.h>
17#include <linux/tty_flip.h>
18#include <linux/delay.h>
19
20/* All registers are 32-bit width */
21
22#define LINCR1 0x0000 /* LIN control register */
23#define LINIER 0x0004 /* LIN interrupt enable register */
24#define LINSR 0x0008 /* LIN status register */
25#define LINESR 0x000C /* LIN error status register */
26#define UARTCR 0x0010 /* UART mode control register */
27#define UARTSR 0x0014 /* UART mode status register */
28#define LINTCSR 0x0018 /* LIN timeout control status register */
29#define LINOCR 0x001C /* LIN output compare register */
30#define LINTOCR 0x0020 /* LIN timeout control register */
31#define LINFBRR 0x0024 /* LIN fractional baud rate register */
32#define LINIBRR 0x0028 /* LIN integer baud rate register */
33#define LINCFR 0x002C /* LIN checksum field register */
34#define LINCR2 0x0030 /* LIN control register 2 */
35#define BIDR 0x0034 /* Buffer identifier register */
36#define BDRL 0x0038 /* Buffer data register least significant */
37#define BDRM 0x003C /* Buffer data register most significant */
38#define IFER 0x0040 /* Identifier filter enable register */
39#define IFMI 0x0044 /* Identifier filter match index */
40#define IFMR 0x0048 /* Identifier filter mode register */
41#define GCR 0x004C /* Global control register */
42#define UARTPTO 0x0050 /* UART preset timeout register */
43#define UARTCTO 0x0054 /* UART current timeout register */
44
45/*
46 * Register field definitions
47 */
48
49#define LINFLEXD_LINCR1_INIT BIT(0)
50#define LINFLEXD_LINCR1_MME BIT(4)
51#define LINFLEXD_LINCR1_BF BIT(7)
52
53#define LINFLEXD_LINSR_LINS_INITMODE BIT(12)
54#define LINFLEXD_LINSR_LINS_MASK (0xF << 12)
55
56#define LINFLEXD_LINIER_SZIE BIT(15)
57#define LINFLEXD_LINIER_OCIE BIT(14)
58#define LINFLEXD_LINIER_BEIE BIT(13)
59#define LINFLEXD_LINIER_CEIE BIT(12)
60#define LINFLEXD_LINIER_HEIE BIT(11)
61#define LINFLEXD_LINIER_FEIE BIT(8)
62#define LINFLEXD_LINIER_BOIE BIT(7)
63#define LINFLEXD_LINIER_LSIE BIT(6)
64#define LINFLEXD_LINIER_WUIE BIT(5)
65#define LINFLEXD_LINIER_DBFIE BIT(4)
66#define LINFLEXD_LINIER_DBEIETOIE BIT(3)
67#define LINFLEXD_LINIER_DRIE BIT(2)
68#define LINFLEXD_LINIER_DTIE BIT(1)
69#define LINFLEXD_LINIER_HRIE BIT(0)
70
71#define LINFLEXD_UARTCR_OSR_MASK (0xF << 24)
72#define LINFLEXD_UARTCR_OSR(uartcr) (((uartcr) \
73 & LINFLEXD_UARTCR_OSR_MASK) >> 24)
74
75#define LINFLEXD_UARTCR_ROSE BIT(23)
76
77#define LINFLEXD_UARTCR_RFBM BIT(9)
78#define LINFLEXD_UARTCR_TFBM BIT(8)
79#define LINFLEXD_UARTCR_WL1 BIT(7)
80#define LINFLEXD_UARTCR_PC1 BIT(6)
81
82#define LINFLEXD_UARTCR_RXEN BIT(5)
83#define LINFLEXD_UARTCR_TXEN BIT(4)
84#define LINFLEXD_UARTCR_PC0 BIT(3)
85
86#define LINFLEXD_UARTCR_PCE BIT(2)
87#define LINFLEXD_UARTCR_WL0 BIT(1)
88#define LINFLEXD_UARTCR_UART BIT(0)
89
90#define LINFLEXD_UARTSR_SZF BIT(15)
91#define LINFLEXD_UARTSR_OCF BIT(14)
92#define LINFLEXD_UARTSR_PE3 BIT(13)
93#define LINFLEXD_UARTSR_PE2 BIT(12)
94#define LINFLEXD_UARTSR_PE1 BIT(11)
95#define LINFLEXD_UARTSR_PE0 BIT(10)
96#define LINFLEXD_UARTSR_RMB BIT(9)
97#define LINFLEXD_UARTSR_FEF BIT(8)
98#define LINFLEXD_UARTSR_BOF BIT(7)
99#define LINFLEXD_UARTSR_RPS BIT(6)
100#define LINFLEXD_UARTSR_WUF BIT(5)
101#define LINFLEXD_UARTSR_4 BIT(4)
102
103#define LINFLEXD_UARTSR_TO BIT(3)
104
105#define LINFLEXD_UARTSR_DRFRFE BIT(2)
106#define LINFLEXD_UARTSR_DTFTFF BIT(1)
107#define LINFLEXD_UARTSR_NF BIT(0)
108#define LINFLEXD_UARTSR_PE (LINFLEXD_UARTSR_PE0 |\
109 LINFLEXD_UARTSR_PE1 |\
110 LINFLEXD_UARTSR_PE2 |\
111 LINFLEXD_UARTSR_PE3)
112
113#define LINFLEX_LDIV_MULTIPLIER (16)
114
115#define DRIVER_NAME "fsl-linflexuart"
116#define DEV_NAME "ttyLF"
117#define UART_NR 4
118
119#define EARLYCON_BUFFER_INITIAL_CAP 8
120
121#define PREINIT_DELAY 2000 /* us */
122
123static const struct of_device_id linflex_dt_ids[] = {
124 {
125 .compatible = "fsl,s32v234-linflexuart",
126 },
127 { /* sentinel */ }
128};
129MODULE_DEVICE_TABLE(of, linflex_dt_ids);
130
131#ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
132static struct uart_port *earlycon_port;
133static bool linflex_earlycon_same_instance;
134static DEFINE_SPINLOCK(init_lock);
135static bool during_init;
136
137static struct {
138 char *content;
139 unsigned int len, cap;
140} earlycon_buf;
141#endif
142
143static void linflex_stop_tx(struct uart_port *port)
144{
145 unsigned long ier;
146
147 ier = readl(addr: port->membase + LINIER);
148 ier &= ~(LINFLEXD_LINIER_DTIE);
149 writel(val: ier, addr: port->membase + LINIER);
150}
151
152static void linflex_stop_rx(struct uart_port *port)
153{
154 unsigned long ier;
155
156 ier = readl(addr: port->membase + LINIER);
157 writel(val: ier & ~LINFLEXD_LINIER_DRIE, addr: port->membase + LINIER);
158}
159
160static void linflex_put_char(struct uart_port *sport, unsigned char c)
161{
162 unsigned long status;
163
164 writeb(val: c, addr: sport->membase + BDRL);
165
166 /* Waiting for data transmission completed. */
167 while (((status = readl(addr: sport->membase + UARTSR)) &
168 LINFLEXD_UARTSR_DTFTFF) !=
169 LINFLEXD_UARTSR_DTFTFF)
170 ;
171
172 writel(val: status | LINFLEXD_UARTSR_DTFTFF, addr: sport->membase + UARTSR);
173}
174
175static inline void linflex_transmit_buffer(struct uart_port *sport)
176{
177 struct circ_buf *xmit = &sport->state->xmit;
178
179 while (!uart_circ_empty(xmit)) {
180 linflex_put_char(sport, c: xmit->buf[xmit->tail]);
181 uart_xmit_advance(up: sport, chars: 1);
182 }
183
184 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
185 uart_write_wakeup(port: sport);
186
187 if (uart_circ_empty(xmit))
188 linflex_stop_tx(port: sport);
189}
190
191static void linflex_start_tx(struct uart_port *port)
192{
193 unsigned long ier;
194
195 linflex_transmit_buffer(sport: port);
196 ier = readl(addr: port->membase + LINIER);
197 writel(val: ier | LINFLEXD_LINIER_DTIE, addr: port->membase + LINIER);
198}
199
200static irqreturn_t linflex_txint(int irq, void *dev_id)
201{
202 struct uart_port *sport = dev_id;
203 struct circ_buf *xmit = &sport->state->xmit;
204 unsigned long flags;
205
206 uart_port_lock_irqsave(up: sport, flags: &flags);
207
208 if (sport->x_char) {
209 linflex_put_char(sport, c: sport->x_char);
210 goto out;
211 }
212
213 if (uart_circ_empty(xmit) || uart_tx_stopped(port: sport)) {
214 linflex_stop_tx(port: sport);
215 goto out;
216 }
217
218 linflex_transmit_buffer(sport);
219out:
220 uart_port_unlock_irqrestore(up: sport, flags);
221 return IRQ_HANDLED;
222}
223
224static irqreturn_t linflex_rxint(int irq, void *dev_id)
225{
226 struct uart_port *sport = dev_id;
227 unsigned int flg;
228 struct tty_port *port = &sport->state->port;
229 unsigned long flags, status;
230 unsigned char rx;
231 bool brk;
232
233 uart_port_lock_irqsave(up: sport, flags: &flags);
234
235 status = readl(addr: sport->membase + UARTSR);
236 while (status & LINFLEXD_UARTSR_RMB) {
237 rx = readb(addr: sport->membase + BDRM);
238 brk = false;
239 flg = TTY_NORMAL;
240 sport->icount.rx++;
241
242 if (status & (LINFLEXD_UARTSR_BOF | LINFLEXD_UARTSR_FEF |
243 LINFLEXD_UARTSR_PE)) {
244 if (status & LINFLEXD_UARTSR_BOF)
245 sport->icount.overrun++;
246 if (status & LINFLEXD_UARTSR_FEF) {
247 if (!rx) {
248 brk = true;
249 sport->icount.brk++;
250 } else
251 sport->icount.frame++;
252 }
253 if (status & LINFLEXD_UARTSR_PE)
254 sport->icount.parity++;
255 }
256
257 writel(val: status, addr: sport->membase + UARTSR);
258 status = readl(addr: sport->membase + UARTSR);
259
260 if (brk) {
261 uart_handle_break(port: sport);
262 } else {
263 if (uart_handle_sysrq_char(port: sport, ch: (unsigned char)rx))
264 continue;
265 tty_insert_flip_char(port, ch: rx, flag: flg);
266 }
267 }
268
269 uart_port_unlock_irqrestore(up: sport, flags);
270
271 tty_flip_buffer_push(port);
272
273 return IRQ_HANDLED;
274}
275
276static irqreturn_t linflex_int(int irq, void *dev_id)
277{
278 struct uart_port *sport = dev_id;
279 unsigned long status;
280
281 status = readl(addr: sport->membase + UARTSR);
282
283 if (status & LINFLEXD_UARTSR_DRFRFE)
284 linflex_rxint(irq, dev_id);
285 if (status & LINFLEXD_UARTSR_DTFTFF)
286 linflex_txint(irq, dev_id);
287
288 return IRQ_HANDLED;
289}
290
291/* return TIOCSER_TEMT when transmitter is not busy */
292static unsigned int linflex_tx_empty(struct uart_port *port)
293{
294 unsigned long status;
295
296 status = readl(addr: port->membase + UARTSR) & LINFLEXD_UARTSR_DTFTFF;
297
298 return status ? TIOCSER_TEMT : 0;
299}
300
301static unsigned int linflex_get_mctrl(struct uart_port *port)
302{
303 return 0;
304}
305
306static void linflex_set_mctrl(struct uart_port *port, unsigned int mctrl)
307{
308}
309
310static void linflex_break_ctl(struct uart_port *port, int break_state)
311{
312}
313
314static void linflex_setup_watermark(struct uart_port *sport)
315{
316 unsigned long cr, ier, cr1;
317
318 /* Disable transmission/reception */
319 ier = readl(addr: sport->membase + LINIER);
320 ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
321 writel(val: ier, addr: sport->membase + LINIER);
322
323 cr = readl(addr: sport->membase + UARTCR);
324 cr &= ~(LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN);
325 writel(val: cr, addr: sport->membase + UARTCR);
326
327 /* Enter initialization mode by setting INIT bit */
328
329 /* set the Linflex in master mode and activate by-pass filter */
330 cr1 = LINFLEXD_LINCR1_BF | LINFLEXD_LINCR1_MME
331 | LINFLEXD_LINCR1_INIT;
332 writel(val: cr1, addr: sport->membase + LINCR1);
333
334 /* wait for init mode entry */
335 while ((readl(addr: sport->membase + LINSR)
336 & LINFLEXD_LINSR_LINS_MASK)
337 != LINFLEXD_LINSR_LINS_INITMODE)
338 ;
339
340 /*
341 * UART = 0x1; - Linflex working in UART mode
342 * TXEN = 0x1; - Enable transmission of data now
343 * RXEn = 0x1; - Receiver enabled
344 * WL0 = 0x1; - 8 bit data
345 * PCE = 0x0; - No parity
346 */
347
348 /* set UART bit to allow writing other bits */
349 writel(LINFLEXD_UARTCR_UART, addr: sport->membase + UARTCR);
350
351 cr = (LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN |
352 LINFLEXD_UARTCR_WL0 | LINFLEXD_UARTCR_UART);
353
354 writel(val: cr, addr: sport->membase + UARTCR);
355
356 cr1 &= ~(LINFLEXD_LINCR1_INIT);
357
358 writel(val: cr1, addr: sport->membase + LINCR1);
359
360 ier = readl(addr: sport->membase + LINIER);
361 ier |= LINFLEXD_LINIER_DRIE;
362 ier |= LINFLEXD_LINIER_DTIE;
363
364 writel(val: ier, addr: sport->membase + LINIER);
365}
366
367static int linflex_startup(struct uart_port *port)
368{
369 int ret = 0;
370 unsigned long flags;
371
372 uart_port_lock_irqsave(up: port, flags: &flags);
373
374 linflex_setup_watermark(sport: port);
375
376 uart_port_unlock_irqrestore(up: port, flags);
377
378 ret = devm_request_irq(dev: port->dev, irq: port->irq, handler: linflex_int, irqflags: 0,
379 DRIVER_NAME, dev_id: port);
380
381 return ret;
382}
383
384static void linflex_shutdown(struct uart_port *port)
385{
386 unsigned long ier;
387 unsigned long flags;
388
389 uart_port_lock_irqsave(up: port, flags: &flags);
390
391 /* disable interrupts */
392 ier = readl(addr: port->membase + LINIER);
393 ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
394 writel(val: ier, addr: port->membase + LINIER);
395
396 uart_port_unlock_irqrestore(up: port, flags);
397
398 devm_free_irq(dev: port->dev, irq: port->irq, dev_id: port);
399}
400
401static void
402linflex_set_termios(struct uart_port *port, struct ktermios *termios,
403 const struct ktermios *old)
404{
405 unsigned long flags;
406 unsigned long cr, old_cr, cr1;
407 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
408
409 cr = readl(addr: port->membase + UARTCR);
410 old_cr = cr;
411
412 /* Enter initialization mode by setting INIT bit */
413 cr1 = readl(addr: port->membase + LINCR1);
414 cr1 |= LINFLEXD_LINCR1_INIT;
415 writel(val: cr1, addr: port->membase + LINCR1);
416
417 /* wait for init mode entry */
418 while ((readl(addr: port->membase + LINSR)
419 & LINFLEXD_LINSR_LINS_MASK)
420 != LINFLEXD_LINSR_LINS_INITMODE)
421 ;
422
423 /*
424 * only support CS8 and CS7, and for CS7 must enable PE.
425 * supported mode:
426 * - (7,e/o,1)
427 * - (8,n,1)
428 * - (8,e/o,1)
429 */
430 /* enter the UART into configuration mode */
431
432 while ((termios->c_cflag & CSIZE) != CS8 &&
433 (termios->c_cflag & CSIZE) != CS7) {
434 termios->c_cflag &= ~CSIZE;
435 termios->c_cflag |= old_csize;
436 old_csize = CS8;
437 }
438
439 if ((termios->c_cflag & CSIZE) == CS7) {
440 /* Word length: WL1WL0:00 */
441 cr = old_cr & ~LINFLEXD_UARTCR_WL1 & ~LINFLEXD_UARTCR_WL0;
442 }
443
444 if ((termios->c_cflag & CSIZE) == CS8) {
445 /* Word length: WL1WL0:01 */
446 cr = (old_cr | LINFLEXD_UARTCR_WL0) & ~LINFLEXD_UARTCR_WL1;
447 }
448
449 if (termios->c_cflag & CMSPAR) {
450 if ((termios->c_cflag & CSIZE) != CS8) {
451 termios->c_cflag &= ~CSIZE;
452 termios->c_cflag |= CS8;
453 }
454 /* has a space/sticky bit */
455 cr |= LINFLEXD_UARTCR_WL0;
456 }
457
458 if (termios->c_cflag & CSTOPB)
459 termios->c_cflag &= ~CSTOPB;
460
461 /* parity must be enabled when CS7 to match 8-bits format */
462 if ((termios->c_cflag & CSIZE) == CS7)
463 termios->c_cflag |= PARENB;
464
465 if ((termios->c_cflag & PARENB)) {
466 cr |= LINFLEXD_UARTCR_PCE;
467 if (termios->c_cflag & PARODD)
468 cr = (cr | LINFLEXD_UARTCR_PC0) &
469 (~LINFLEXD_UARTCR_PC1);
470 else
471 cr = cr & (~LINFLEXD_UARTCR_PC1 &
472 ~LINFLEXD_UARTCR_PC0);
473 } else {
474 cr &= ~LINFLEXD_UARTCR_PCE;
475 }
476
477 uart_port_lock_irqsave(up: port, flags: &flags);
478
479 port->read_status_mask = 0;
480
481 if (termios->c_iflag & INPCK)
482 port->read_status_mask |= (LINFLEXD_UARTSR_FEF |
483 LINFLEXD_UARTSR_PE0 |
484 LINFLEXD_UARTSR_PE1 |
485 LINFLEXD_UARTSR_PE2 |
486 LINFLEXD_UARTSR_PE3);
487 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
488 port->read_status_mask |= LINFLEXD_UARTSR_FEF;
489
490 /* characters to ignore */
491 port->ignore_status_mask = 0;
492 if (termios->c_iflag & IGNPAR)
493 port->ignore_status_mask |= LINFLEXD_UARTSR_PE;
494 if (termios->c_iflag & IGNBRK) {
495 port->ignore_status_mask |= LINFLEXD_UARTSR_PE;
496 /*
497 * if we're ignoring parity and break indicators,
498 * ignore overruns too (for real raw support).
499 */
500 if (termios->c_iflag & IGNPAR)
501 port->ignore_status_mask |= LINFLEXD_UARTSR_BOF;
502 }
503
504 writel(val: cr, addr: port->membase + UARTCR);
505
506 cr1 &= ~(LINFLEXD_LINCR1_INIT);
507
508 writel(val: cr1, addr: port->membase + LINCR1);
509
510 uart_port_unlock_irqrestore(up: port, flags);
511}
512
513static const char *linflex_type(struct uart_port *port)
514{
515 return "FSL_LINFLEX";
516}
517
518static void linflex_release_port(struct uart_port *port)
519{
520 /* nothing to do */
521}
522
523static int linflex_request_port(struct uart_port *port)
524{
525 return 0;
526}
527
528/* configure/auto-configure the port */
529static void linflex_config_port(struct uart_port *port, int flags)
530{
531 if (flags & UART_CONFIG_TYPE)
532 port->type = PORT_LINFLEXUART;
533}
534
535static const struct uart_ops linflex_pops = {
536 .tx_empty = linflex_tx_empty,
537 .set_mctrl = linflex_set_mctrl,
538 .get_mctrl = linflex_get_mctrl,
539 .stop_tx = linflex_stop_tx,
540 .start_tx = linflex_start_tx,
541 .stop_rx = linflex_stop_rx,
542 .break_ctl = linflex_break_ctl,
543 .startup = linflex_startup,
544 .shutdown = linflex_shutdown,
545 .set_termios = linflex_set_termios,
546 .type = linflex_type,
547 .request_port = linflex_request_port,
548 .release_port = linflex_release_port,
549 .config_port = linflex_config_port,
550};
551
552static struct uart_port *linflex_ports[UART_NR];
553
554#ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
555static void linflex_console_putchar(struct uart_port *port, unsigned char ch)
556{
557 unsigned long cr;
558
559 cr = readl(addr: port->membase + UARTCR);
560
561 writeb(val: ch, addr: port->membase + BDRL);
562
563 if (!(cr & LINFLEXD_UARTCR_TFBM))
564 while ((readl(addr: port->membase + UARTSR) &
565 LINFLEXD_UARTSR_DTFTFF)
566 != LINFLEXD_UARTSR_DTFTFF)
567 ;
568 else
569 while (readl(addr: port->membase + UARTSR) &
570 LINFLEXD_UARTSR_DTFTFF)
571 ;
572
573 if (!(cr & LINFLEXD_UARTCR_TFBM)) {
574 writel(val: (readl(addr: port->membase + UARTSR) |
575 LINFLEXD_UARTSR_DTFTFF),
576 addr: port->membase + UARTSR);
577 }
578}
579
580static void linflex_earlycon_putchar(struct uart_port *port, unsigned char ch)
581{
582 unsigned long flags;
583 char *ret;
584
585 if (!linflex_earlycon_same_instance) {
586 linflex_console_putchar(port, ch);
587 return;
588 }
589
590 spin_lock_irqsave(&init_lock, flags);
591 if (!during_init)
592 goto outside_init;
593
594 if (earlycon_buf.len >= 1 << CONFIG_LOG_BUF_SHIFT)
595 goto init_release;
596
597 if (!earlycon_buf.cap) {
598 earlycon_buf.content = kmalloc(EARLYCON_BUFFER_INITIAL_CAP,
599 GFP_ATOMIC);
600 earlycon_buf.cap = earlycon_buf.content ?
601 EARLYCON_BUFFER_INITIAL_CAP : 0;
602 } else if (earlycon_buf.len == earlycon_buf.cap) {
603 ret = krealloc(objp: earlycon_buf.content, new_size: earlycon_buf.cap << 1,
604 GFP_ATOMIC);
605 if (ret) {
606 earlycon_buf.content = ret;
607 earlycon_buf.cap <<= 1;
608 }
609 }
610
611 if (earlycon_buf.len < earlycon_buf.cap)
612 earlycon_buf.content[earlycon_buf.len++] = ch;
613
614 goto init_release;
615
616outside_init:
617 linflex_console_putchar(port, ch);
618init_release:
619 spin_unlock_irqrestore(lock: &init_lock, flags);
620}
621
622static void linflex_string_write(struct uart_port *sport, const char *s,
623 unsigned int count)
624{
625 unsigned long cr, ier = 0;
626
627 ier = readl(addr: sport->membase + LINIER);
628 linflex_stop_tx(port: sport);
629
630 cr = readl(addr: sport->membase + UARTCR);
631 cr |= (LINFLEXD_UARTCR_TXEN);
632 writel(val: cr, addr: sport->membase + UARTCR);
633
634 uart_console_write(port: sport, s, count, putchar: linflex_console_putchar);
635
636 writel(val: ier, addr: sport->membase + LINIER);
637}
638
639static void
640linflex_console_write(struct console *co, const char *s, unsigned int count)
641{
642 struct uart_port *sport = linflex_ports[co->index];
643 unsigned long flags;
644 int locked = 1;
645
646 if (sport->sysrq)
647 locked = 0;
648 else if (oops_in_progress)
649 locked = uart_port_trylock_irqsave(up: sport, flags: &flags);
650 else
651 uart_port_lock_irqsave(up: sport, flags: &flags);
652
653 linflex_string_write(sport, s, count);
654
655 if (locked)
656 uart_port_unlock_irqrestore(up: sport, flags);
657}
658
659/*
660 * if the port was already initialised (eg, by a boot loader),
661 * try to determine the current setup.
662 */
663static void __init
664linflex_console_get_options(struct uart_port *sport, int *parity, int *bits)
665{
666 unsigned long cr;
667
668 cr = readl(addr: sport->membase + UARTCR);
669 cr &= LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN;
670
671 if (!cr)
672 return;
673
674 /* ok, the port was enabled */
675
676 *parity = 'n';
677 if (cr & LINFLEXD_UARTCR_PCE) {
678 if (cr & LINFLEXD_UARTCR_PC0)
679 *parity = 'o';
680 else
681 *parity = 'e';
682 }
683
684 if ((cr & LINFLEXD_UARTCR_WL0) && ((cr & LINFLEXD_UARTCR_WL1) == 0)) {
685 if (cr & LINFLEXD_UARTCR_PCE)
686 *bits = 9;
687 else
688 *bits = 8;
689 }
690}
691
692static int __init linflex_console_setup(struct console *co, char *options)
693{
694 struct uart_port *sport;
695 int baud = 115200;
696 int bits = 8;
697 int parity = 'n';
698 int flow = 'n';
699 int ret;
700 int i;
701 unsigned long flags;
702 /*
703 * check whether an invalid uart number has been specified, and
704 * if so, search for the first available port that does have
705 * console support.
706 */
707 if (co->index == -1 || co->index >= ARRAY_SIZE(linflex_ports))
708 co->index = 0;
709
710 sport = linflex_ports[co->index];
711 if (!sport)
712 return -ENODEV;
713
714 if (options)
715 uart_parse_options(options, baud: &baud, parity: &parity, bits: &bits, flow: &flow);
716 else
717 linflex_console_get_options(sport, parity: &parity, bits: &bits);
718
719 if (earlycon_port && sport->mapbase == earlycon_port->mapbase) {
720 linflex_earlycon_same_instance = true;
721
722 spin_lock_irqsave(&init_lock, flags);
723 during_init = true;
724 spin_unlock_irqrestore(lock: &init_lock, flags);
725
726 /* Workaround for character loss or output of many invalid
727 * characters, when INIT mode is entered shortly after a
728 * character has just been printed.
729 */
730 udelay(PREINIT_DELAY);
731 }
732
733 linflex_setup_watermark(sport);
734
735 ret = uart_set_options(port: sport, co, baud, parity, bits, flow);
736
737 if (!linflex_earlycon_same_instance)
738 goto done;
739
740 spin_lock_irqsave(&init_lock, flags);
741
742 /* Emptying buffer */
743 if (earlycon_buf.len) {
744 for (i = 0; i < earlycon_buf.len; i++)
745 linflex_console_putchar(port: earlycon_port,
746 ch: earlycon_buf.content[i]);
747
748 kfree(objp: earlycon_buf.content);
749 earlycon_buf.len = 0;
750 }
751
752 during_init = false;
753 spin_unlock_irqrestore(lock: &init_lock, flags);
754
755done:
756 return ret;
757}
758
759static struct uart_driver linflex_reg;
760static struct console linflex_console = {
761 .name = DEV_NAME,
762 .write = linflex_console_write,
763 .device = uart_console_device,
764 .setup = linflex_console_setup,
765 .flags = CON_PRINTBUFFER,
766 .index = -1,
767 .data = &linflex_reg,
768};
769
770static void linflex_earlycon_write(struct console *con, const char *s,
771 unsigned int n)
772{
773 struct earlycon_device *dev = con->data;
774
775 uart_console_write(port: &dev->port, s, count: n, putchar: linflex_earlycon_putchar);
776}
777
778static int __init linflex_early_console_setup(struct earlycon_device *device,
779 const char *options)
780{
781 if (!device->port.membase)
782 return -ENODEV;
783
784 device->con->write = linflex_earlycon_write;
785 earlycon_port = &device->port;
786
787 return 0;
788}
789
790OF_EARLYCON_DECLARE(linflex, "fsl,s32v234-linflexuart",
791 linflex_early_console_setup);
792
793#define LINFLEX_CONSOLE (&linflex_console)
794#else
795#define LINFLEX_CONSOLE NULL
796#endif
797
798static struct uart_driver linflex_reg = {
799 .owner = THIS_MODULE,
800 .driver_name = DRIVER_NAME,
801 .dev_name = DEV_NAME,
802 .nr = ARRAY_SIZE(linflex_ports),
803 .cons = LINFLEX_CONSOLE,
804};
805
806static int linflex_probe(struct platform_device *pdev)
807{
808 struct device_node *np = pdev->dev.of_node;
809 struct uart_port *sport;
810 struct resource *res;
811 int ret;
812
813 sport = devm_kzalloc(dev: &pdev->dev, size: sizeof(*sport), GFP_KERNEL);
814 if (!sport)
815 return -ENOMEM;
816
817 ret = of_alias_get_id(np, stem: "serial");
818 if (ret < 0) {
819 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
820 return ret;
821 }
822 if (ret >= UART_NR) {
823 dev_err(&pdev->dev, "driver limited to %d serial ports\n",
824 UART_NR);
825 return -ENOMEM;
826 }
827
828 sport->line = ret;
829
830 sport->membase = devm_platform_get_and_ioremap_resource(pdev, index: 0, res: &res);
831 if (IS_ERR(ptr: sport->membase))
832 return PTR_ERR(ptr: sport->membase);
833 sport->mapbase = res->start;
834
835 ret = platform_get_irq(pdev, 0);
836 if (ret < 0)
837 return ret;
838
839 sport->dev = &pdev->dev;
840 sport->iotype = UPIO_MEM;
841 sport->irq = ret;
842 sport->ops = &linflex_pops;
843 sport->flags = UPF_BOOT_AUTOCONF;
844 sport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE);
845
846 linflex_ports[sport->line] = sport;
847
848 platform_set_drvdata(pdev, data: sport);
849
850 return uart_add_one_port(reg: &linflex_reg, port: sport);
851}
852
853static void linflex_remove(struct platform_device *pdev)
854{
855 struct uart_port *sport = platform_get_drvdata(pdev);
856
857 uart_remove_one_port(reg: &linflex_reg, port: sport);
858}
859
860#ifdef CONFIG_PM_SLEEP
861static int linflex_suspend(struct device *dev)
862{
863 struct uart_port *sport = dev_get_drvdata(dev);
864
865 uart_suspend_port(reg: &linflex_reg, port: sport);
866
867 return 0;
868}
869
870static int linflex_resume(struct device *dev)
871{
872 struct uart_port *sport = dev_get_drvdata(dev);
873
874 uart_resume_port(reg: &linflex_reg, port: sport);
875
876 return 0;
877}
878#endif
879
880static SIMPLE_DEV_PM_OPS(linflex_pm_ops, linflex_suspend, linflex_resume);
881
882static struct platform_driver linflex_driver = {
883 .probe = linflex_probe,
884 .remove_new = linflex_remove,
885 .driver = {
886 .name = DRIVER_NAME,
887 .of_match_table = linflex_dt_ids,
888 .pm = &linflex_pm_ops,
889 },
890};
891
892static int __init linflex_serial_init(void)
893{
894 int ret;
895
896 ret = uart_register_driver(uart: &linflex_reg);
897 if (ret)
898 return ret;
899
900 ret = platform_driver_register(&linflex_driver);
901 if (ret)
902 uart_unregister_driver(uart: &linflex_reg);
903
904 return ret;
905}
906
907static void __exit linflex_serial_exit(void)
908{
909 platform_driver_unregister(&linflex_driver);
910 uart_unregister_driver(uart: &linflex_reg);
911}
912
913module_init(linflex_serial_init);
914module_exit(linflex_serial_exit);
915
916MODULE_DESCRIPTION("Freescale LINFlexD serial port driver");
917MODULE_LICENSE("GPL v2");
918

source code of linux/drivers/tty/serial/fsl_linflexuart.c