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/of_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
123 static const struct of_device_id linflex_dt_ids[] = {
124 {
125 .compatible = "fsl,s32v234-linflexuart",
126 },
127 { /* sentinel */ }
128 };
129 MODULE_DEVICE_TABLE(of, linflex_dt_ids);
130
131 #ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
132 static struct uart_port *earlycon_port;
133 static bool linflex_earlycon_same_instance;
134 static DEFINE_SPINLOCK(init_lock);
135 static bool during_init;
136
137 static struct {
138 char *content;
139 unsigned int len, cap;
140 } earlycon_buf;
141 #endif
142
linflex_stop_tx(struct uart_port * port)143 static void linflex_stop_tx(struct uart_port *port)
144 {
145 unsigned long ier;
146
147 ier = readl(port->membase + LINIER);
148 ier &= ~(LINFLEXD_LINIER_DTIE);
149 writel(ier, port->membase + LINIER);
150 }
151
linflex_stop_rx(struct uart_port * port)152 static void linflex_stop_rx(struct uart_port *port)
153 {
154 unsigned long ier;
155
156 ier = readl(port->membase + LINIER);
157 writel(ier & ~LINFLEXD_LINIER_DRIE, port->membase + LINIER);
158 }
159
linflex_put_char(struct uart_port * sport,unsigned char c)160 static void linflex_put_char(struct uart_port *sport, unsigned char c)
161 {
162 unsigned long status;
163
164 writeb(c, sport->membase + BDRL);
165
166 /* Waiting for data transmission completed. */
167 while (((status = readl(sport->membase + UARTSR)) &
168 LINFLEXD_UARTSR_DTFTFF) !=
169 LINFLEXD_UARTSR_DTFTFF)
170 ;
171
172 writel(status | LINFLEXD_UARTSR_DTFTFF, sport->membase + UARTSR);
173 }
174
linflex_transmit_buffer(struct uart_port * sport)175 static 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, xmit->buf[xmit->tail]);
181 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
182 sport->icount.tx++;
183 }
184
185 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
186 uart_write_wakeup(sport);
187
188 if (uart_circ_empty(xmit))
189 linflex_stop_tx(sport);
190 }
191
linflex_start_tx(struct uart_port * port)192 static void linflex_start_tx(struct uart_port *port)
193 {
194 unsigned long ier;
195
196 linflex_transmit_buffer(port);
197 ier = readl(port->membase + LINIER);
198 writel(ier | LINFLEXD_LINIER_DTIE, port->membase + LINIER);
199 }
200
linflex_txint(int irq,void * dev_id)201 static irqreturn_t linflex_txint(int irq, void *dev_id)
202 {
203 struct uart_port *sport = dev_id;
204 struct circ_buf *xmit = &sport->state->xmit;
205 unsigned long flags;
206
207 spin_lock_irqsave(&sport->lock, flags);
208
209 if (sport->x_char) {
210 linflex_put_char(sport, sport->x_char);
211 goto out;
212 }
213
214 if (uart_circ_empty(xmit) || uart_tx_stopped(sport)) {
215 linflex_stop_tx(sport);
216 goto out;
217 }
218
219 linflex_transmit_buffer(sport);
220 out:
221 spin_unlock_irqrestore(&sport->lock, flags);
222 return IRQ_HANDLED;
223 }
224
linflex_rxint(int irq,void * dev_id)225 static irqreturn_t linflex_rxint(int irq, void *dev_id)
226 {
227 struct uart_port *sport = dev_id;
228 unsigned int flg;
229 struct tty_port *port = &sport->state->port;
230 unsigned long flags, status;
231 unsigned char rx;
232 bool brk;
233
234 spin_lock_irqsave(&sport->lock, flags);
235
236 status = readl(sport->membase + UARTSR);
237 while (status & LINFLEXD_UARTSR_RMB) {
238 rx = readb(sport->membase + BDRM);
239 brk = false;
240 flg = TTY_NORMAL;
241 sport->icount.rx++;
242
243 if (status & (LINFLEXD_UARTSR_BOF | LINFLEXD_UARTSR_FEF |
244 LINFLEXD_UARTSR_PE)) {
245 if (status & LINFLEXD_UARTSR_BOF)
246 sport->icount.overrun++;
247 if (status & LINFLEXD_UARTSR_FEF) {
248 if (!rx) {
249 brk = true;
250 sport->icount.brk++;
251 } else
252 sport->icount.frame++;
253 }
254 if (status & LINFLEXD_UARTSR_PE)
255 sport->icount.parity++;
256 }
257
258 writel(status, sport->membase + UARTSR);
259 status = readl(sport->membase + UARTSR);
260
261 if (brk) {
262 uart_handle_break(sport);
263 } else {
264 if (uart_handle_sysrq_char(sport, (unsigned char)rx))
265 continue;
266 tty_insert_flip_char(port, rx, flg);
267 }
268 }
269
270 spin_unlock_irqrestore(&sport->lock, flags);
271
272 tty_flip_buffer_push(port);
273
274 return IRQ_HANDLED;
275 }
276
linflex_int(int irq,void * dev_id)277 static irqreturn_t linflex_int(int irq, void *dev_id)
278 {
279 struct uart_port *sport = dev_id;
280 unsigned long status;
281
282 status = readl(sport->membase + UARTSR);
283
284 if (status & LINFLEXD_UARTSR_DRFRFE)
285 linflex_rxint(irq, dev_id);
286 if (status & LINFLEXD_UARTSR_DTFTFF)
287 linflex_txint(irq, dev_id);
288
289 return IRQ_HANDLED;
290 }
291
292 /* return TIOCSER_TEMT when transmitter is not busy */
linflex_tx_empty(struct uart_port * port)293 static unsigned int linflex_tx_empty(struct uart_port *port)
294 {
295 unsigned long status;
296
297 status = readl(port->membase + UARTSR) & LINFLEXD_UARTSR_DTFTFF;
298
299 return status ? TIOCSER_TEMT : 0;
300 }
301
linflex_get_mctrl(struct uart_port * port)302 static unsigned int linflex_get_mctrl(struct uart_port *port)
303 {
304 return 0;
305 }
306
linflex_set_mctrl(struct uart_port * port,unsigned int mctrl)307 static void linflex_set_mctrl(struct uart_port *port, unsigned int mctrl)
308 {
309 }
310
linflex_break_ctl(struct uart_port * port,int break_state)311 static void linflex_break_ctl(struct uart_port *port, int break_state)
312 {
313 }
314
linflex_setup_watermark(struct uart_port * sport)315 static void linflex_setup_watermark(struct uart_port *sport)
316 {
317 unsigned long cr, ier, cr1;
318
319 /* Disable transmission/reception */
320 ier = readl(sport->membase + LINIER);
321 ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
322 writel(ier, sport->membase + LINIER);
323
324 cr = readl(sport->membase + UARTCR);
325 cr &= ~(LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN);
326 writel(cr, sport->membase + UARTCR);
327
328 /* Enter initialization mode by setting INIT bit */
329
330 /* set the Linflex in master mode and activate by-pass filter */
331 cr1 = LINFLEXD_LINCR1_BF | LINFLEXD_LINCR1_MME
332 | LINFLEXD_LINCR1_INIT;
333 writel(cr1, sport->membase + LINCR1);
334
335 /* wait for init mode entry */
336 while ((readl(sport->membase + LINSR)
337 & LINFLEXD_LINSR_LINS_MASK)
338 != LINFLEXD_LINSR_LINS_INITMODE)
339 ;
340
341 /*
342 * UART = 0x1; - Linflex working in UART mode
343 * TXEN = 0x1; - Enable transmission of data now
344 * RXEn = 0x1; - Receiver enabled
345 * WL0 = 0x1; - 8 bit data
346 * PCE = 0x0; - No parity
347 */
348
349 /* set UART bit to allow writing other bits */
350 writel(LINFLEXD_UARTCR_UART, sport->membase + UARTCR);
351
352 cr = (LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN |
353 LINFLEXD_UARTCR_WL0 | LINFLEXD_UARTCR_UART);
354
355 writel(cr, sport->membase + UARTCR);
356
357 cr1 &= ~(LINFLEXD_LINCR1_INIT);
358
359 writel(cr1, sport->membase + LINCR1);
360
361 ier = readl(sport->membase + LINIER);
362 ier |= LINFLEXD_LINIER_DRIE;
363 ier |= LINFLEXD_LINIER_DTIE;
364
365 writel(ier, sport->membase + LINIER);
366 }
367
linflex_startup(struct uart_port * port)368 static int linflex_startup(struct uart_port *port)
369 {
370 int ret = 0;
371 unsigned long flags;
372
373 spin_lock_irqsave(&port->lock, flags);
374
375 linflex_setup_watermark(port);
376
377 spin_unlock_irqrestore(&port->lock, flags);
378
379 ret = devm_request_irq(port->dev, port->irq, linflex_int, 0,
380 DRIVER_NAME, port);
381
382 return ret;
383 }
384
linflex_shutdown(struct uart_port * port)385 static void linflex_shutdown(struct uart_port *port)
386 {
387 unsigned long ier;
388 unsigned long flags;
389
390 spin_lock_irqsave(&port->lock, flags);
391
392 /* disable interrupts */
393 ier = readl(port->membase + LINIER);
394 ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
395 writel(ier, port->membase + LINIER);
396
397 spin_unlock_irqrestore(&port->lock, flags);
398
399 devm_free_irq(port->dev, port->irq, port);
400 }
401
402 static void
linflex_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)403 linflex_set_termios(struct uart_port *port, struct ktermios *termios,
404 const struct ktermios *old)
405 {
406 unsigned long flags;
407 unsigned long cr, old_cr, cr1;
408 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
409
410 cr = readl(port->membase + UARTCR);
411 old_cr = cr;
412
413 /* Enter initialization mode by setting INIT bit */
414 cr1 = readl(port->membase + LINCR1);
415 cr1 |= LINFLEXD_LINCR1_INIT;
416 writel(cr1, port->membase + LINCR1);
417
418 /* wait for init mode entry */
419 while ((readl(port->membase + LINSR)
420 & LINFLEXD_LINSR_LINS_MASK)
421 != LINFLEXD_LINSR_LINS_INITMODE)
422 ;
423
424 /*
425 * only support CS8 and CS7, and for CS7 must enable PE.
426 * supported mode:
427 * - (7,e/o,1)
428 * - (8,n,1)
429 * - (8,e/o,1)
430 */
431 /* enter the UART into configuration mode */
432
433 while ((termios->c_cflag & CSIZE) != CS8 &&
434 (termios->c_cflag & CSIZE) != CS7) {
435 termios->c_cflag &= ~CSIZE;
436 termios->c_cflag |= old_csize;
437 old_csize = CS8;
438 }
439
440 if ((termios->c_cflag & CSIZE) == CS7) {
441 /* Word length: WL1WL0:00 */
442 cr = old_cr & ~LINFLEXD_UARTCR_WL1 & ~LINFLEXD_UARTCR_WL0;
443 }
444
445 if ((termios->c_cflag & CSIZE) == CS8) {
446 /* Word length: WL1WL0:01 */
447 cr = (old_cr | LINFLEXD_UARTCR_WL0) & ~LINFLEXD_UARTCR_WL1;
448 }
449
450 if (termios->c_cflag & CMSPAR) {
451 if ((termios->c_cflag & CSIZE) != CS8) {
452 termios->c_cflag &= ~CSIZE;
453 termios->c_cflag |= CS8;
454 }
455 /* has a space/sticky bit */
456 cr |= LINFLEXD_UARTCR_WL0;
457 }
458
459 if (termios->c_cflag & CSTOPB)
460 termios->c_cflag &= ~CSTOPB;
461
462 /* parity must be enabled when CS7 to match 8-bits format */
463 if ((termios->c_cflag & CSIZE) == CS7)
464 termios->c_cflag |= PARENB;
465
466 if ((termios->c_cflag & PARENB)) {
467 cr |= LINFLEXD_UARTCR_PCE;
468 if (termios->c_cflag & PARODD)
469 cr = (cr | LINFLEXD_UARTCR_PC0) &
470 (~LINFLEXD_UARTCR_PC1);
471 else
472 cr = cr & (~LINFLEXD_UARTCR_PC1 &
473 ~LINFLEXD_UARTCR_PC0);
474 } else {
475 cr &= ~LINFLEXD_UARTCR_PCE;
476 }
477
478 spin_lock_irqsave(&port->lock, flags);
479
480 port->read_status_mask = 0;
481
482 if (termios->c_iflag & INPCK)
483 port->read_status_mask |= (LINFLEXD_UARTSR_FEF |
484 LINFLEXD_UARTSR_PE0 |
485 LINFLEXD_UARTSR_PE1 |
486 LINFLEXD_UARTSR_PE2 |
487 LINFLEXD_UARTSR_PE3);
488 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
489 port->read_status_mask |= LINFLEXD_UARTSR_FEF;
490
491 /* characters to ignore */
492 port->ignore_status_mask = 0;
493 if (termios->c_iflag & IGNPAR)
494 port->ignore_status_mask |= LINFLEXD_UARTSR_PE;
495 if (termios->c_iflag & IGNBRK) {
496 port->ignore_status_mask |= LINFLEXD_UARTSR_PE;
497 /*
498 * if we're ignoring parity and break indicators,
499 * ignore overruns too (for real raw support).
500 */
501 if (termios->c_iflag & IGNPAR)
502 port->ignore_status_mask |= LINFLEXD_UARTSR_BOF;
503 }
504
505 writel(cr, port->membase + UARTCR);
506
507 cr1 &= ~(LINFLEXD_LINCR1_INIT);
508
509 writel(cr1, port->membase + LINCR1);
510
511 spin_unlock_irqrestore(&port->lock, flags);
512 }
513
linflex_type(struct uart_port * port)514 static const char *linflex_type(struct uart_port *port)
515 {
516 return "FSL_LINFLEX";
517 }
518
linflex_release_port(struct uart_port * port)519 static void linflex_release_port(struct uart_port *port)
520 {
521 /* nothing to do */
522 }
523
linflex_request_port(struct uart_port * port)524 static int linflex_request_port(struct uart_port *port)
525 {
526 return 0;
527 }
528
529 /* configure/auto-configure the port */
linflex_config_port(struct uart_port * port,int flags)530 static void linflex_config_port(struct uart_port *port, int flags)
531 {
532 if (flags & UART_CONFIG_TYPE)
533 port->type = PORT_LINFLEXUART;
534 }
535
536 static const struct uart_ops linflex_pops = {
537 .tx_empty = linflex_tx_empty,
538 .set_mctrl = linflex_set_mctrl,
539 .get_mctrl = linflex_get_mctrl,
540 .stop_tx = linflex_stop_tx,
541 .start_tx = linflex_start_tx,
542 .stop_rx = linflex_stop_rx,
543 .break_ctl = linflex_break_ctl,
544 .startup = linflex_startup,
545 .shutdown = linflex_shutdown,
546 .set_termios = linflex_set_termios,
547 .type = linflex_type,
548 .request_port = linflex_request_port,
549 .release_port = linflex_release_port,
550 .config_port = linflex_config_port,
551 };
552
553 static struct uart_port *linflex_ports[UART_NR];
554
555 #ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
linflex_console_putchar(struct uart_port * port,unsigned char ch)556 static void linflex_console_putchar(struct uart_port *port, unsigned char ch)
557 {
558 unsigned long cr;
559
560 cr = readl(port->membase + UARTCR);
561
562 writeb(ch, port->membase + BDRL);
563
564 if (!(cr & LINFLEXD_UARTCR_TFBM))
565 while ((readl(port->membase + UARTSR) &
566 LINFLEXD_UARTSR_DTFTFF)
567 != LINFLEXD_UARTSR_DTFTFF)
568 ;
569 else
570 while (readl(port->membase + UARTSR) &
571 LINFLEXD_UARTSR_DTFTFF)
572 ;
573
574 if (!(cr & LINFLEXD_UARTCR_TFBM)) {
575 writel((readl(port->membase + UARTSR) |
576 LINFLEXD_UARTSR_DTFTFF),
577 port->membase + UARTSR);
578 }
579 }
580
linflex_earlycon_putchar(struct uart_port * port,unsigned char ch)581 static void linflex_earlycon_putchar(struct uart_port *port, unsigned char ch)
582 {
583 unsigned long flags;
584 char *ret;
585
586 if (!linflex_earlycon_same_instance) {
587 linflex_console_putchar(port, ch);
588 return;
589 }
590
591 spin_lock_irqsave(&init_lock, flags);
592 if (!during_init)
593 goto outside_init;
594
595 if (earlycon_buf.len >= 1 << CONFIG_LOG_BUF_SHIFT)
596 goto init_release;
597
598 if (!earlycon_buf.cap) {
599 earlycon_buf.content = kmalloc(EARLYCON_BUFFER_INITIAL_CAP,
600 GFP_ATOMIC);
601 earlycon_buf.cap = earlycon_buf.content ?
602 EARLYCON_BUFFER_INITIAL_CAP : 0;
603 } else if (earlycon_buf.len == earlycon_buf.cap) {
604 ret = krealloc(earlycon_buf.content, earlycon_buf.cap << 1,
605 GFP_ATOMIC);
606 if (ret) {
607 earlycon_buf.content = ret;
608 earlycon_buf.cap <<= 1;
609 }
610 }
611
612 if (earlycon_buf.len < earlycon_buf.cap)
613 earlycon_buf.content[earlycon_buf.len++] = ch;
614
615 goto init_release;
616
617 outside_init:
618 linflex_console_putchar(port, ch);
619 init_release:
620 spin_unlock_irqrestore(&init_lock, flags);
621 }
622
linflex_string_write(struct uart_port * sport,const char * s,unsigned int count)623 static void linflex_string_write(struct uart_port *sport, const char *s,
624 unsigned int count)
625 {
626 unsigned long cr, ier = 0;
627
628 ier = readl(sport->membase + LINIER);
629 linflex_stop_tx(sport);
630
631 cr = readl(sport->membase + UARTCR);
632 cr |= (LINFLEXD_UARTCR_TXEN);
633 writel(cr, sport->membase + UARTCR);
634
635 uart_console_write(sport, s, count, linflex_console_putchar);
636
637 writel(ier, sport->membase + LINIER);
638 }
639
640 static void
linflex_console_write(struct console * co,const char * s,unsigned int count)641 linflex_console_write(struct console *co, const char *s, unsigned int count)
642 {
643 struct uart_port *sport = linflex_ports[co->index];
644 unsigned long flags;
645 int locked = 1;
646
647 if (sport->sysrq)
648 locked = 0;
649 else if (oops_in_progress)
650 locked = spin_trylock_irqsave(&sport->lock, flags);
651 else
652 spin_lock_irqsave(&sport->lock, flags);
653
654 linflex_string_write(sport, s, count);
655
656 if (locked)
657 spin_unlock_irqrestore(&sport->lock, flags);
658 }
659
660 /*
661 * if the port was already initialised (eg, by a boot loader),
662 * try to determine the current setup.
663 */
664 static void __init
linflex_console_get_options(struct uart_port * sport,int * parity,int * bits)665 linflex_console_get_options(struct uart_port *sport, int *parity, int *bits)
666 {
667 unsigned long cr;
668
669 cr = readl(sport->membase + UARTCR);
670 cr &= LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN;
671
672 if (!cr)
673 return;
674
675 /* ok, the port was enabled */
676
677 *parity = 'n';
678 if (cr & LINFLEXD_UARTCR_PCE) {
679 if (cr & LINFLEXD_UARTCR_PC0)
680 *parity = 'o';
681 else
682 *parity = 'e';
683 }
684
685 if ((cr & LINFLEXD_UARTCR_WL0) && ((cr & LINFLEXD_UARTCR_WL1) == 0)) {
686 if (cr & LINFLEXD_UARTCR_PCE)
687 *bits = 9;
688 else
689 *bits = 8;
690 }
691 }
692
linflex_console_setup(struct console * co,char * options)693 static int __init linflex_console_setup(struct console *co, char *options)
694 {
695 struct uart_port *sport;
696 int baud = 115200;
697 int bits = 8;
698 int parity = 'n';
699 int flow = 'n';
700 int ret;
701 int i;
702 unsigned long flags;
703 /*
704 * check whether an invalid uart number has been specified, and
705 * if so, search for the first available port that does have
706 * console support.
707 */
708 if (co->index == -1 || co->index >= ARRAY_SIZE(linflex_ports))
709 co->index = 0;
710
711 sport = linflex_ports[co->index];
712 if (!sport)
713 return -ENODEV;
714
715 if (options)
716 uart_parse_options(options, &baud, &parity, &bits, &flow);
717 else
718 linflex_console_get_options(sport, &parity, &bits);
719
720 if (earlycon_port && sport->mapbase == earlycon_port->mapbase) {
721 linflex_earlycon_same_instance = true;
722
723 spin_lock_irqsave(&init_lock, flags);
724 during_init = true;
725 spin_unlock_irqrestore(&init_lock, flags);
726
727 /* Workaround for character loss or output of many invalid
728 * characters, when INIT mode is entered shortly after a
729 * character has just been printed.
730 */
731 udelay(PREINIT_DELAY);
732 }
733
734 linflex_setup_watermark(sport);
735
736 ret = uart_set_options(sport, co, baud, parity, bits, flow);
737
738 if (!linflex_earlycon_same_instance)
739 goto done;
740
741 spin_lock_irqsave(&init_lock, flags);
742
743 /* Emptying buffer */
744 if (earlycon_buf.len) {
745 for (i = 0; i < earlycon_buf.len; i++)
746 linflex_console_putchar(earlycon_port,
747 earlycon_buf.content[i]);
748
749 kfree(earlycon_buf.content);
750 earlycon_buf.len = 0;
751 }
752
753 during_init = false;
754 spin_unlock_irqrestore(&init_lock, flags);
755
756 done:
757 return ret;
758 }
759
760 static struct uart_driver linflex_reg;
761 static struct console linflex_console = {
762 .name = DEV_NAME,
763 .write = linflex_console_write,
764 .device = uart_console_device,
765 .setup = linflex_console_setup,
766 .flags = CON_PRINTBUFFER,
767 .index = -1,
768 .data = &linflex_reg,
769 };
770
linflex_earlycon_write(struct console * con,const char * s,unsigned int n)771 static void linflex_earlycon_write(struct console *con, const char *s,
772 unsigned int n)
773 {
774 struct earlycon_device *dev = con->data;
775
776 uart_console_write(&dev->port, s, n, linflex_earlycon_putchar);
777 }
778
linflex_early_console_setup(struct earlycon_device * device,const char * options)779 static int __init linflex_early_console_setup(struct earlycon_device *device,
780 const char *options)
781 {
782 if (!device->port.membase)
783 return -ENODEV;
784
785 device->con->write = linflex_earlycon_write;
786 earlycon_port = &device->port;
787
788 return 0;
789 }
790
791 OF_EARLYCON_DECLARE(linflex, "fsl,s32v234-linflexuart",
792 linflex_early_console_setup);
793
794 #define LINFLEX_CONSOLE (&linflex_console)
795 #else
796 #define LINFLEX_CONSOLE NULL
797 #endif
798
799 static struct uart_driver linflex_reg = {
800 .owner = THIS_MODULE,
801 .driver_name = DRIVER_NAME,
802 .dev_name = DEV_NAME,
803 .nr = ARRAY_SIZE(linflex_ports),
804 .cons = LINFLEX_CONSOLE,
805 };
806
linflex_probe(struct platform_device * pdev)807 static int linflex_probe(struct platform_device *pdev)
808 {
809 struct device_node *np = pdev->dev.of_node;
810 struct uart_port *sport;
811 struct resource *res;
812 int ret;
813
814 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
815 if (!sport)
816 return -ENOMEM;
817
818 ret = of_alias_get_id(np, "serial");
819 if (ret < 0) {
820 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
821 return ret;
822 }
823 if (ret >= UART_NR) {
824 dev_err(&pdev->dev, "driver limited to %d serial ports\n",
825 UART_NR);
826 return -ENOMEM;
827 }
828
829 sport->line = ret;
830
831 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
832 if (!res)
833 return -ENODEV;
834
835 sport->mapbase = res->start;
836 sport->membase = devm_ioremap_resource(&pdev->dev, res);
837 if (IS_ERR(sport->membase))
838 return PTR_ERR(sport->membase);
839
840 sport->dev = &pdev->dev;
841 sport->type = PORT_LINFLEXUART;
842 sport->iotype = UPIO_MEM;
843 sport->irq = platform_get_irq(pdev, 0);
844 sport->ops = &linflex_pops;
845 sport->flags = UPF_BOOT_AUTOCONF;
846 sport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE);
847
848 linflex_ports[sport->line] = sport;
849
850 platform_set_drvdata(pdev, sport);
851
852 return uart_add_one_port(&linflex_reg, sport);
853 }
854
linflex_remove(struct platform_device * pdev)855 static int linflex_remove(struct platform_device *pdev)
856 {
857 struct uart_port *sport = platform_get_drvdata(pdev);
858
859 uart_remove_one_port(&linflex_reg, sport);
860
861 return 0;
862 }
863
864 #ifdef CONFIG_PM_SLEEP
linflex_suspend(struct device * dev)865 static int linflex_suspend(struct device *dev)
866 {
867 struct uart_port *sport = dev_get_drvdata(dev);
868
869 uart_suspend_port(&linflex_reg, sport);
870
871 return 0;
872 }
873
linflex_resume(struct device * dev)874 static int linflex_resume(struct device *dev)
875 {
876 struct uart_port *sport = dev_get_drvdata(dev);
877
878 uart_resume_port(&linflex_reg, sport);
879
880 return 0;
881 }
882 #endif
883
884 static SIMPLE_DEV_PM_OPS(linflex_pm_ops, linflex_suspend, linflex_resume);
885
886 static struct platform_driver linflex_driver = {
887 .probe = linflex_probe,
888 .remove = linflex_remove,
889 .driver = {
890 .name = DRIVER_NAME,
891 .of_match_table = linflex_dt_ids,
892 .pm = &linflex_pm_ops,
893 },
894 };
895
linflex_serial_init(void)896 static int __init linflex_serial_init(void)
897 {
898 int ret;
899
900 ret = uart_register_driver(&linflex_reg);
901 if (ret)
902 return ret;
903
904 ret = platform_driver_register(&linflex_driver);
905 if (ret)
906 uart_unregister_driver(&linflex_reg);
907
908 return ret;
909 }
910
linflex_serial_exit(void)911 static void __exit linflex_serial_exit(void)
912 {
913 platform_driver_unregister(&linflex_driver);
914 uart_unregister_driver(&linflex_reg);
915 }
916
917 module_init(linflex_serial_init);
918 module_exit(linflex_serial_exit);
919
920 MODULE_DESCRIPTION("Freescale LINFlexD serial port driver");
921 MODULE_LICENSE("GPL v2");
922