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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
4 *
5 * Copyright (C) 2004 Infineon IFAP DC COM CPE
6 * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
7 * Copyright (C) 2007 John Crispin <john@phrozen.org>
8 * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
9 */
10
11#include <linux/bitfield.h>
12#include <linux/clk.h>
13#include <linux/console.h>
14#include <linux/device.h>
15#include <linux/init.h>
16#include <linux/io.h>
17#include <linux/ioport.h>
18#include <linux/lantiq.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/platform_device.h>
22#include <linux/serial.h>
23#include <linux/serial_core.h>
24#include <linux/slab.h>
25#include <linux/sysrq.h>
26#include <linux/tty.h>
27#include <linux/tty_flip.h>
28
29#define PORT_LTQ_ASC 111
30#define MAXPORTS 2
31#define UART_DUMMY_UER_RX 1
32#define DRVNAME "lantiq,asc"
33#ifdef __BIG_ENDIAN
34#define LTQ_ASC_TBUF (0x0020 + 3)
35#define LTQ_ASC_RBUF (0x0024 + 3)
36#else
37#define LTQ_ASC_TBUF 0x0020
38#define LTQ_ASC_RBUF 0x0024
39#endif
40#define LTQ_ASC_FSTAT 0x0048
41#define LTQ_ASC_WHBSTATE 0x0018
42#define LTQ_ASC_STATE 0x0014
43#define LTQ_ASC_IRNCR 0x00F8
44#define LTQ_ASC_CLC 0x0000
45#define LTQ_ASC_ID 0x0008
46#define LTQ_ASC_PISEL 0x0004
47#define LTQ_ASC_TXFCON 0x0044
48#define LTQ_ASC_RXFCON 0x0040
49#define LTQ_ASC_CON 0x0010
50#define LTQ_ASC_BG 0x0050
51#define LTQ_ASC_IRNREN 0x00F4
52
53#define ASC_IRNREN_TX 0x1
54#define ASC_IRNREN_RX 0x2
55#define ASC_IRNREN_ERR 0x4
56#define ASC_IRNREN_TX_BUF 0x8
57#define ASC_IRNCR_TIR 0x1
58#define ASC_IRNCR_RIR 0x2
59#define ASC_IRNCR_EIR 0x4
60#define ASC_IRNCR_MASK GENMASK(2, 0)
61
62#define ASCOPT_CSIZE 0x3
63#define TXFIFO_FL 1
64#define RXFIFO_FL 1
65#define ASCCLC_DISS 0x2
66#define ASCCLC_RMCMASK 0x0000FF00
67#define ASCCLC_RMCOFFSET 8
68#define ASCCON_M_8ASYNC 0x0
69#define ASCCON_M_7ASYNC 0x2
70#define ASCCON_ODD 0x00000020
71#define ASCCON_STP 0x00000080
72#define ASCCON_BRS 0x00000100
73#define ASCCON_FDE 0x00000200
74#define ASCCON_R 0x00008000
75#define ASCCON_FEN 0x00020000
76#define ASCCON_ROEN 0x00080000
77#define ASCCON_TOEN 0x00100000
78#define ASCSTATE_PE 0x00010000
79#define ASCSTATE_FE 0x00020000
80#define ASCSTATE_ROE 0x00080000
81#define ASCSTATE_ANY (ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
82#define ASCWHBSTATE_CLRREN 0x00000001
83#define ASCWHBSTATE_SETREN 0x00000002
84#define ASCWHBSTATE_CLRPE 0x00000004
85#define ASCWHBSTATE_CLRFE 0x00000008
86#define ASCWHBSTATE_CLRROE 0x00000020
87#define ASCTXFCON_TXFEN 0x0001
88#define ASCTXFCON_TXFFLU 0x0002
89#define ASCTXFCON_TXFITLMASK 0x3F00
90#define ASCTXFCON_TXFITLOFF 8
91#define ASCRXFCON_RXFEN 0x0001
92#define ASCRXFCON_RXFFLU 0x0002
93#define ASCRXFCON_RXFITLMASK 0x3F00
94#define ASCRXFCON_RXFITLOFF 8
95#define ASCFSTAT_RXFFLMASK 0x003F
96#define ASCFSTAT_TXFFLMASK 0x3F00
97#define ASCFSTAT_TXFREEMASK 0x3F000000
98
99static struct ltq_uart_port *lqasc_port[MAXPORTS];
100static struct uart_driver lqasc_reg;
101
102struct ltq_soc_data {
103 int (*fetch_irq)(struct device *dev, struct ltq_uart_port *ltq_port);
104 int (*request_irq)(struct uart_port *port);
105 void (*free_irq)(struct uart_port *port);
106};
107
108struct ltq_uart_port {
109 struct uart_port port;
110 /* clock used to derive divider */
111 struct clk *freqclk;
112 /* clock gating of the ASC core */
113 struct clk *clk;
114 unsigned int tx_irq;
115 unsigned int rx_irq;
116 unsigned int err_irq;
117 unsigned int common_irq;
118 spinlock_t lock; /* exclusive access for multi core */
119
120 const struct ltq_soc_data *soc;
121};
122
123static inline void asc_update_bits(u32 clear, u32 set, void __iomem *reg)
124{
125 u32 tmp = __raw_readl(reg);
126
127 __raw_writel((tmp & ~clear) | set, reg);
128}
129
130static inline struct
131ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
132{
133 return container_of(port, struct ltq_uart_port, port);
134}
135
136static void
137lqasc_stop_tx(struct uart_port *port)
138{
139 return;
140}
141
142static bool lqasc_tx_ready(struct uart_port *port)
143{
144 u32 fstat = __raw_readl(port->membase + LTQ_ASC_FSTAT);
145
146 return FIELD_GET(ASCFSTAT_TXFREEMASK, fstat);
147}
148
149static void
150lqasc_start_tx(struct uart_port *port)
151{
152 unsigned long flags;
153 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
154 u8 ch;
155
156 spin_lock_irqsave(<q_port->lock, flags);
157 uart_port_tx(port, ch,
158 lqasc_tx_ready(port),
159 writeb(ch, port->membase + LTQ_ASC_TBUF));
160 spin_unlock_irqrestore(<q_port->lock, flags);
161 return;
162}
163
164static void
165lqasc_stop_rx(struct uart_port *port)
166{
167 __raw_writel(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
168}
169
170static int
171lqasc_rx_chars(struct uart_port *port)
172{
173 struct tty_port *tport = &port->state->port;
174 unsigned int ch = 0, rsr = 0, fifocnt;
175
176 fifocnt = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
177 ASCFSTAT_RXFFLMASK;
178 while (fifocnt--) {
179 u8 flag = TTY_NORMAL;
180 ch = readb(port->membase + LTQ_ASC_RBUF);
181 rsr = (__raw_readl(port->membase + LTQ_ASC_STATE)
182 & ASCSTATE_ANY) | UART_DUMMY_UER_RX;
183 tty_flip_buffer_push(tport);
184 port->icount.rx++;
185
186 /*
187 * Note that the error handling code is
188 * out of the main execution path
189 */
190 if (rsr & ASCSTATE_ANY) {
191 if (rsr & ASCSTATE_PE) {
192 port->icount.parity++;
193 asc_update_bits(0, ASCWHBSTATE_CLRPE,
194 port->membase + LTQ_ASC_WHBSTATE);
195 } else if (rsr & ASCSTATE_FE) {
196 port->icount.frame++;
197 asc_update_bits(0, ASCWHBSTATE_CLRFE,
198 port->membase + LTQ_ASC_WHBSTATE);
199 }
200 if (rsr & ASCSTATE_ROE) {
201 port->icount.overrun++;
202 asc_update_bits(0, ASCWHBSTATE_CLRROE,
203 port->membase + LTQ_ASC_WHBSTATE);
204 }
205
206 rsr &= port->read_status_mask;
207
208 if (rsr & ASCSTATE_PE)
209 flag = TTY_PARITY;
210 else if (rsr & ASCSTATE_FE)
211 flag = TTY_FRAME;
212 }
213
214 if ((rsr & port->ignore_status_mask) == 0)
215 tty_insert_flip_char(tport, ch, flag);
216
217 if (rsr & ASCSTATE_ROE)
218 /*
219 * Overrun is special, since it's reported
220 * immediately, and doesn't affect the current
221 * character
222 */
223 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
224 }
225
226 if (ch != 0)
227 tty_flip_buffer_push(tport);
228
229 return 0;
230}
231
232static irqreturn_t
233lqasc_tx_int(int irq, void *_port)
234{
235 unsigned long flags;
236 struct uart_port *port = (struct uart_port *)_port;
237 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
238
239 spin_lock_irqsave(<q_port->lock, flags);
240 __raw_writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
241 spin_unlock_irqrestore(<q_port->lock, flags);
242 lqasc_start_tx(port);
243 return IRQ_HANDLED;
244}
245
246static irqreturn_t
247lqasc_err_int(int irq, void *_port)
248{
249 unsigned long flags;
250 struct uart_port *port = (struct uart_port *)_port;
251 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
252
253 spin_lock_irqsave(<q_port->lock, flags);
254 __raw_writel(ASC_IRNCR_EIR, port->membase + LTQ_ASC_IRNCR);
255 /* clear any pending interrupts */
256 asc_update_bits(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
257 ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
258 spin_unlock_irqrestore(<q_port->lock, flags);
259 return IRQ_HANDLED;
260}
261
262static irqreturn_t
263lqasc_rx_int(int irq, void *_port)
264{
265 unsigned long flags;
266 struct uart_port *port = (struct uart_port *)_port;
267 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
268
269 spin_lock_irqsave(<q_port->lock, flags);
270 __raw_writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
271 lqasc_rx_chars(port);
272 spin_unlock_irqrestore(<q_port->lock, flags);
273 return IRQ_HANDLED;
274}
275
276static irqreturn_t lqasc_irq(int irq, void *p)
277{
278 unsigned long flags;
279 u32 stat;
280 struct uart_port *port = p;
281 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
282
283 spin_lock_irqsave(<q_port->lock, flags);
284 stat = readl(port->membase + LTQ_ASC_IRNCR);
285 spin_unlock_irqrestore(<q_port->lock, flags);
286 if (!(stat & ASC_IRNCR_MASK))
287 return IRQ_NONE;
288
289 if (stat & ASC_IRNCR_TIR)
290 lqasc_tx_int(irq, p);
291
292 if (stat & ASC_IRNCR_RIR)
293 lqasc_rx_int(irq, p);
294
295 if (stat & ASC_IRNCR_EIR)
296 lqasc_err_int(irq, p);
297
298 return IRQ_HANDLED;
299}
300
301static unsigned int
302lqasc_tx_empty(struct uart_port *port)
303{
304 int status;
305 status = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
306 ASCFSTAT_TXFFLMASK;
307 return status ? 0 : TIOCSER_TEMT;
308}
309
310static unsigned int
311lqasc_get_mctrl(struct uart_port *port)
312{
313 return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR;
314}
315
316static void
317lqasc_set_mctrl(struct uart_port *port, u_int mctrl)
318{
319}
320
321static void
322lqasc_break_ctl(struct uart_port *port, int break_state)
323{
324}
325
326static int
327lqasc_startup(struct uart_port *port)
328{
329 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
330 int retval;
331 unsigned long flags;
332
333 if (!IS_ERR(ltq_port->clk))
334 clk_prepare_enable(ltq_port->clk);
335 port->uartclk = clk_get_rate(ltq_port->freqclk);
336
337 spin_lock_irqsave(<q_port->lock, flags);
338 asc_update_bits(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
339 port->membase + LTQ_ASC_CLC);
340
341 __raw_writel(0, port->membase + LTQ_ASC_PISEL);
342 __raw_writel(
343 ((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
344 ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
345 port->membase + LTQ_ASC_TXFCON);
346 __raw_writel(
347 ((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
348 | ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
349 port->membase + LTQ_ASC_RXFCON);
350 /* make sure other settings are written to hardware before
351 * setting enable bits
352 */
353 wmb();
354 asc_update_bits(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
355 ASCCON_ROEN, port->membase + LTQ_ASC_CON);
356
357 spin_unlock_irqrestore(<q_port->lock, flags);
358
359 retval = ltq_port->soc->request_irq(port);
360 if (retval)
361 return retval;
362
363 __raw_writel(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
364 port->membase + LTQ_ASC_IRNREN);
365 return retval;
366}
367
368static void
369lqasc_shutdown(struct uart_port *port)
370{
371 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
372 unsigned long flags;
373
374 ltq_port->soc->free_irq(port);
375
376 spin_lock_irqsave(<q_port->lock, flags);
377 __raw_writel(0, port->membase + LTQ_ASC_CON);
378 asc_update_bits(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
379 port->membase + LTQ_ASC_RXFCON);
380 asc_update_bits(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
381 port->membase + LTQ_ASC_TXFCON);
382 spin_unlock_irqrestore(<q_port->lock, flags);
383 if (!IS_ERR(ltq_port->clk))
384 clk_disable_unprepare(ltq_port->clk);
385}
386
387static void
388lqasc_set_termios(struct uart_port *port, struct ktermios *new,
389 const struct ktermios *old)
390{
391 unsigned int cflag;
392 unsigned int iflag;
393 unsigned int divisor;
394 unsigned int baud;
395 unsigned int con = 0;
396 unsigned long flags;
397 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
398
399 cflag = new->c_cflag;
400 iflag = new->c_iflag;
401
402 switch (cflag & CSIZE) {
403 case CS7:
404 con = ASCCON_M_7ASYNC;
405 break;
406
407 case CS5:
408 case CS6:
409 default:
410 new->c_cflag &= ~ CSIZE;
411 new->c_cflag |= CS8;
412 con = ASCCON_M_8ASYNC;
413 break;
414 }
415
416 cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
417
418 if (cflag & CSTOPB)
419 con |= ASCCON_STP;
420
421 if (cflag & PARENB) {
422 if (!(cflag & PARODD))
423 con &= ~ASCCON_ODD;
424 else
425 con |= ASCCON_ODD;
426 }
427
428 port->read_status_mask = ASCSTATE_ROE;
429 if (iflag & INPCK)
430 port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
431
432 port->ignore_status_mask = 0;
433 if (iflag & IGNPAR)
434 port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
435
436 if (iflag & IGNBRK) {
437 /*
438 * If we're ignoring parity and break indicators,
439 * ignore overruns too (for real raw support).
440 */
441 if (iflag & IGNPAR)
442 port->ignore_status_mask |= ASCSTATE_ROE;
443 }
444
445 if ((cflag & CREAD) == 0)
446 port->ignore_status_mask |= UART_DUMMY_UER_RX;
447
448 /* set error signals - framing, parity and overrun, enable receiver */
449 con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
450
451 spin_lock_irqsave(<q_port->lock, flags);
452
453 /* set up CON */
454 asc_update_bits(0, con, port->membase + LTQ_ASC_CON);
455
456 /* Set baud rate - take a divider of 2 into account */
457 baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
458 divisor = uart_get_divisor(port, baud);
459 divisor = divisor / 2 - 1;
460
461 /* disable the baudrate generator */
462 asc_update_bits(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
463
464 /* make sure the fractional divider is off */
465 asc_update_bits(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
466
467 /* set up to use divisor of 2 */
468 asc_update_bits(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
469
470 /* now we can write the new baudrate into the register */
471 __raw_writel(divisor, port->membase + LTQ_ASC_BG);
472
473 /* turn the baudrate generator back on */
474 asc_update_bits(0, ASCCON_R, port->membase + LTQ_ASC_CON);
475
476 /* enable rx */
477 __raw_writel(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
478
479 spin_unlock_irqrestore(<q_port->lock, flags);
480
481 /* Don't rewrite B0 */
482 if (tty_termios_baud_rate(new))
483 tty_termios_encode_baud_rate(new, baud, baud);
484
485 uart_update_timeout(port, cflag, baud);
486}
487
488static const char*
489lqasc_type(struct uart_port *port)
490{
491 if (port->type == PORT_LTQ_ASC)
492 return DRVNAME;
493 else
494 return NULL;
495}
496
497static void
498lqasc_release_port(struct uart_port *port)
499{
500 struct platform_device *pdev = to_platform_device(port->dev);
501
502 if (port->flags & UPF_IOREMAP) {
503 devm_iounmap(&pdev->dev, port->membase);
504 port->membase = NULL;
505 }
506}
507
508static int
509lqasc_request_port(struct uart_port *port)
510{
511 struct platform_device *pdev = to_platform_device(port->dev);
512 struct resource *res;
513 int size;
514
515 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
516 if (!res) {
517 dev_err(&pdev->dev, "cannot obtain I/O memory region");
518 return -ENODEV;
519 }
520 size = resource_size(res);
521
522 res = devm_request_mem_region(&pdev->dev, res->start,
523 size, dev_name(&pdev->dev));
524 if (!res) {
525 dev_err(&pdev->dev, "cannot request I/O memory region");
526 return -EBUSY;
527 }
528
529 if (port->flags & UPF_IOREMAP) {
530 port->membase = devm_ioremap(&pdev->dev,
531 port->mapbase, size);
532 if (port->membase == NULL)
533 return -ENOMEM;
534 }
535 return 0;
536}
537
538static void
539lqasc_config_port(struct uart_port *port, int flags)
540{
541 if (flags & UART_CONFIG_TYPE) {
542 port->type = PORT_LTQ_ASC;
543 lqasc_request_port(port);
544 }
545}
546
547static int
548lqasc_verify_port(struct uart_port *port,
549 struct serial_struct *ser)
550{
551 int ret = 0;
552 if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC)
553 ret = -EINVAL;
554 if (ser->irq < 0 || ser->irq >= NR_IRQS)
555 ret = -EINVAL;
556 if (ser->baud_base < 9600)
557 ret = -EINVAL;
558 return ret;
559}
560
561static const struct uart_ops lqasc_pops = {
562 .tx_empty = lqasc_tx_empty,
563 .set_mctrl = lqasc_set_mctrl,
564 .get_mctrl = lqasc_get_mctrl,
565 .stop_tx = lqasc_stop_tx,
566 .start_tx = lqasc_start_tx,
567 .stop_rx = lqasc_stop_rx,
568 .break_ctl = lqasc_break_ctl,
569 .startup = lqasc_startup,
570 .shutdown = lqasc_shutdown,
571 .set_termios = lqasc_set_termios,
572 .type = lqasc_type,
573 .release_port = lqasc_release_port,
574 .request_port = lqasc_request_port,
575 .config_port = lqasc_config_port,
576 .verify_port = lqasc_verify_port,
577};
578
579#ifdef CONFIG_SERIAL_LANTIQ_CONSOLE
580static void
581lqasc_console_putchar(struct uart_port *port, unsigned char ch)
582{
583 if (!port->membase)
584 return;
585
586 while (!lqasc_tx_ready(port))
587 ;
588
589 writeb(ch, port->membase + LTQ_ASC_TBUF);
590}
591
592static void lqasc_serial_port_write(struct uart_port *port, const char *s,
593 u_int count)
594{
595 uart_console_write(port, s, count, lqasc_console_putchar);
596}
597
598static void
599lqasc_console_write(struct console *co, const char *s, u_int count)
600{
601 struct ltq_uart_port *ltq_port;
602 unsigned long flags;
603
604 if (co->index >= MAXPORTS)
605 return;
606
607 ltq_port = lqasc_port[co->index];
608 if (!ltq_port)
609 return;
610
611 spin_lock_irqsave(<q_port->lock, flags);
612 lqasc_serial_port_write(<q_port->port, s, count);
613 spin_unlock_irqrestore(<q_port->lock, flags);
614}
615
616static int __init
617lqasc_console_setup(struct console *co, char *options)
618{
619 struct ltq_uart_port *ltq_port;
620 struct uart_port *port;
621 int baud = 115200;
622 int bits = 8;
623 int parity = 'n';
624 int flow = 'n';
625
626 if (co->index >= MAXPORTS)
627 return -ENODEV;
628
629 ltq_port = lqasc_port[co->index];
630 if (!ltq_port)
631 return -ENODEV;
632
633 port = <q_port->port;
634
635 if (!IS_ERR(ltq_port->clk))
636 clk_prepare_enable(ltq_port->clk);
637
638 port->uartclk = clk_get_rate(ltq_port->freqclk);
639
640 if (options)
641 uart_parse_options(options, &baud, &parity, &bits, &flow);
642 return uart_set_options(port, co, baud, parity, bits, flow);
643}
644
645static struct console lqasc_console = {
646 .name = "ttyLTQ",
647 .write = lqasc_console_write,
648 .device = uart_console_device,
649 .setup = lqasc_console_setup,
650 .flags = CON_PRINTBUFFER,
651 .index = -1,
652 .data = &lqasc_reg,
653};
654
655static int __init
656lqasc_console_init(void)
657{
658 register_console(&lqasc_console);
659 return 0;
660}
661console_initcall(lqasc_console_init);
662
663static void lqasc_serial_early_console_write(struct console *co,
664 const char *s,
665 u_int count)
666{
667 struct earlycon_device *dev = co->data;
668
669 lqasc_serial_port_write(&dev->port, s, count);
670}
671
672static int __init
673lqasc_serial_early_console_setup(struct earlycon_device *device,
674 const char *opt)
675{
676 if (!device->port.membase)
677 return -ENODEV;
678
679 device->con->write = lqasc_serial_early_console_write;
680 return 0;
681}
682OF_EARLYCON_DECLARE(lantiq, "lantiq,asc", lqasc_serial_early_console_setup);
683OF_EARLYCON_DECLARE(lantiq, "intel,lgm-asc", lqasc_serial_early_console_setup);
684
685#define LANTIQ_SERIAL_CONSOLE (&lqasc_console)
686
687#else
688
689#define LANTIQ_SERIAL_CONSOLE NULL
690
691#endif /* CONFIG_SERIAL_LANTIQ_CONSOLE */
692
693static struct uart_driver lqasc_reg = {
694 .owner = THIS_MODULE,
695 .driver_name = DRVNAME,
696 .dev_name = "ttyLTQ",
697 .major = 0,
698 .minor = 0,
699 .nr = MAXPORTS,
700 .cons = LANTIQ_SERIAL_CONSOLE,
701};
702
703static int fetch_irq_lantiq(struct device *dev, struct ltq_uart_port *ltq_port)
704{
705 struct uart_port *port = <q_port->port;
706 struct platform_device *pdev = to_platform_device(dev);
707 int irq;
708
709 irq = platform_get_irq(pdev, 0);
710 if (irq < 0)
711 return irq;
712 ltq_port->tx_irq = irq;
713 irq = platform_get_irq(pdev, 1);
714 if (irq < 0)
715 return irq;
716 ltq_port->rx_irq = irq;
717 irq = platform_get_irq(pdev, 2);
718 if (irq < 0)
719 return irq;
720 ltq_port->err_irq = irq;
721
722 port->irq = ltq_port->tx_irq;
723
724 return 0;
725}
726
727static int request_irq_lantiq(struct uart_port *port)
728{
729 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
730 int retval;
731
732 retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
733 0, "asc_tx", port);
734 if (retval) {
735 dev_err(port->dev, "failed to request asc_tx\n");
736 return retval;
737 }
738
739 retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
740 0, "asc_rx", port);
741 if (retval) {
742 dev_err(port->dev, "failed to request asc_rx\n");
743 goto err1;
744 }
745
746 retval = request_irq(ltq_port->err_irq, lqasc_err_int,
747 0, "asc_err", port);
748 if (retval) {
749 dev_err(port->dev, "failed to request asc_err\n");
750 goto err2;
751 }
752 return 0;
753
754err2:
755 free_irq(ltq_port->rx_irq, port);
756err1:
757 free_irq(ltq_port->tx_irq, port);
758 return retval;
759}
760
761static void free_irq_lantiq(struct uart_port *port)
762{
763 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
764
765 free_irq(ltq_port->tx_irq, port);
766 free_irq(ltq_port->rx_irq, port);
767 free_irq(ltq_port->err_irq, port);
768}
769
770static int fetch_irq_intel(struct device *dev, struct ltq_uart_port *ltq_port)
771{
772 struct uart_port *port = <q_port->port;
773 int ret;
774
775 ret = platform_get_irq(to_platform_device(dev), 0);
776 if (ret < 0) {
777 dev_err(dev, "failed to fetch IRQ for serial port\n");
778 return ret;
779 }
780 ltq_port->common_irq = ret;
781 port->irq = ret;
782
783 return 0;
784}
785
786static int request_irq_intel(struct uart_port *port)
787{
788 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
789 int retval;
790
791 retval = request_irq(ltq_port->common_irq, lqasc_irq, 0,
792 "asc_irq", port);
793 if (retval)
794 dev_err(port->dev, "failed to request asc_irq\n");
795
796 return retval;
797}
798
799static void free_irq_intel(struct uart_port *port)
800{
801 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
802
803 free_irq(ltq_port->common_irq, port);
804}
805
806static int lqasc_probe(struct platform_device *pdev)
807{
808 struct device_node *node = pdev->dev.of_node;
809 struct ltq_uart_port *ltq_port;
810 struct uart_port *port;
811 struct resource *mmres;
812 int line;
813 int ret;
814
815 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
816 if (!mmres) {
817 dev_err(&pdev->dev,
818 "failed to get memory for serial port\n");
819 return -ENODEV;
820 }
821
822 ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
823 GFP_KERNEL);
824 if (!ltq_port)
825 return -ENOMEM;
826
827 port = <q_port->port;
828
829 ltq_port->soc = of_device_get_match_data(&pdev->dev);
830 ret = ltq_port->soc->fetch_irq(&pdev->dev, ltq_port);
831 if (ret)
832 return ret;
833
834 /* get serial id */
835 line = of_alias_get_id(node, "serial");
836 if (line < 0) {
837 if (IS_ENABLED(CONFIG_LANTIQ)) {
838 if (mmres->start == CPHYSADDR(LTQ_EARLY_ASC))
839 line = 0;
840 else
841 line = 1;
842 } else {
843 dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
844 line);
845 return line;
846 }
847 }
848
849 if (lqasc_port[line]) {
850 dev_err(&pdev->dev, "port %d already allocated\n", line);
851 return -EBUSY;
852 }
853
854 port->iotype = SERIAL_IO_MEM;
855 port->flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
856 port->ops = &lqasc_pops;
857 port->fifosize = 16;
858 port->type = PORT_LTQ_ASC;
859 port->line = line;
860 port->dev = &pdev->dev;
861 /* unused, just to be backward-compatible */
862 port->mapbase = mmres->start;
863
864 if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
865 ltq_port->freqclk = clk_get_fpi();
866 else
867 ltq_port->freqclk = devm_clk_get(&pdev->dev, "freq");
868
869
870 if (IS_ERR(ltq_port->freqclk)) {
871 pr_err("failed to get fpi clk\n");
872 return -ENOENT;
873 }
874
875 /* not all asc ports have clock gates, lets ignore the return code */
876 if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
877 ltq_port->clk = clk_get(&pdev->dev, NULL);
878 else
879 ltq_port->clk = devm_clk_get(&pdev->dev, "asc");
880
881 spin_lock_init(<q_port->lock);
882 lqasc_port[line] = ltq_port;
883 platform_set_drvdata(pdev, ltq_port);
884
885 ret = uart_add_one_port(&lqasc_reg, port);
886
887 return ret;
888}
889
890static void lqasc_remove(struct platform_device *pdev)
891{
892 struct uart_port *port = platform_get_drvdata(pdev);
893
894 uart_remove_one_port(&lqasc_reg, port);
895}
896
897static const struct ltq_soc_data soc_data_lantiq = {
898 .fetch_irq = fetch_irq_lantiq,
899 .request_irq = request_irq_lantiq,
900 .free_irq = free_irq_lantiq,
901};
902
903static const struct ltq_soc_data soc_data_intel = {
904 .fetch_irq = fetch_irq_intel,
905 .request_irq = request_irq_intel,
906 .free_irq = free_irq_intel,
907};
908
909static const struct of_device_id ltq_asc_match[] = {
910 { .compatible = "lantiq,asc", .data = &soc_data_lantiq },
911 { .compatible = "intel,lgm-asc", .data = &soc_data_intel },
912 {},
913};
914MODULE_DEVICE_TABLE(of, ltq_asc_match);
915
916static struct platform_driver lqasc_driver = {
917 .probe = lqasc_probe,
918 .remove_new = lqasc_remove,
919 .driver = {
920 .name = DRVNAME,
921 .of_match_table = ltq_asc_match,
922 },
923};
924
925static int __init
926init_lqasc(void)
927{
928 int ret;
929
930 ret = uart_register_driver(&lqasc_reg);
931 if (ret != 0)
932 return ret;
933
934 ret = platform_driver_register(&lqasc_driver);
935 if (ret != 0)
936 uart_unregister_driver(&lqasc_reg);
937
938 return ret;
939}
940
941static void __exit exit_lqasc(void)
942{
943 platform_driver_unregister(&lqasc_driver);
944 uart_unregister_driver(&lqasc_reg);
945}
946
947module_init(init_lqasc);
948module_exit(exit_lqasc);
949
950MODULE_DESCRIPTION("Serial driver for Lantiq & Intel gateway SoCs");
951MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
4 *
5 * Copyright (C) 2004 Infineon IFAP DC COM CPE
6 * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
7 * Copyright (C) 2007 John Crispin <john@phrozen.org>
8 * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
9 */
10
11#include <linux/clk.h>
12#include <linux/console.h>
13#include <linux/device.h>
14#include <linux/init.h>
15#include <linux/io.h>
16#include <linux/ioport.h>
17#include <linux/lantiq.h>
18#include <linux/module.h>
19#include <linux/of_address.h>
20#include <linux/of_irq.h>
21#include <linux/of_platform.h>
22#include <linux/serial.h>
23#include <linux/serial_core.h>
24#include <linux/slab.h>
25#include <linux/sysrq.h>
26#include <linux/tty.h>
27#include <linux/tty_flip.h>
28
29#define PORT_LTQ_ASC 111
30#define MAXPORTS 2
31#define UART_DUMMY_UER_RX 1
32#define DRVNAME "lantiq,asc"
33#ifdef __BIG_ENDIAN
34#define LTQ_ASC_TBUF (0x0020 + 3)
35#define LTQ_ASC_RBUF (0x0024 + 3)
36#else
37#define LTQ_ASC_TBUF 0x0020
38#define LTQ_ASC_RBUF 0x0024
39#endif
40#define LTQ_ASC_FSTAT 0x0048
41#define LTQ_ASC_WHBSTATE 0x0018
42#define LTQ_ASC_STATE 0x0014
43#define LTQ_ASC_IRNCR 0x00F8
44#define LTQ_ASC_CLC 0x0000
45#define LTQ_ASC_ID 0x0008
46#define LTQ_ASC_PISEL 0x0004
47#define LTQ_ASC_TXFCON 0x0044
48#define LTQ_ASC_RXFCON 0x0040
49#define LTQ_ASC_CON 0x0010
50#define LTQ_ASC_BG 0x0050
51#define LTQ_ASC_IRNREN 0x00F4
52
53#define ASC_IRNREN_TX 0x1
54#define ASC_IRNREN_RX 0x2
55#define ASC_IRNREN_ERR 0x4
56#define ASC_IRNREN_TX_BUF 0x8
57#define ASC_IRNCR_TIR 0x1
58#define ASC_IRNCR_RIR 0x2
59#define ASC_IRNCR_EIR 0x4
60#define ASC_IRNCR_MASK GENMASK(2, 0)
61
62#define ASCOPT_CSIZE 0x3
63#define TXFIFO_FL 1
64#define RXFIFO_FL 1
65#define ASCCLC_DISS 0x2
66#define ASCCLC_RMCMASK 0x0000FF00
67#define ASCCLC_RMCOFFSET 8
68#define ASCCON_M_8ASYNC 0x0
69#define ASCCON_M_7ASYNC 0x2
70#define ASCCON_ODD 0x00000020
71#define ASCCON_STP 0x00000080
72#define ASCCON_BRS 0x00000100
73#define ASCCON_FDE 0x00000200
74#define ASCCON_R 0x00008000
75#define ASCCON_FEN 0x00020000
76#define ASCCON_ROEN 0x00080000
77#define ASCCON_TOEN 0x00100000
78#define ASCSTATE_PE 0x00010000
79#define ASCSTATE_FE 0x00020000
80#define ASCSTATE_ROE 0x00080000
81#define ASCSTATE_ANY (ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
82#define ASCWHBSTATE_CLRREN 0x00000001
83#define ASCWHBSTATE_SETREN 0x00000002
84#define ASCWHBSTATE_CLRPE 0x00000004
85#define ASCWHBSTATE_CLRFE 0x00000008
86#define ASCWHBSTATE_CLRROE 0x00000020
87#define ASCTXFCON_TXFEN 0x0001
88#define ASCTXFCON_TXFFLU 0x0002
89#define ASCTXFCON_TXFITLMASK 0x3F00
90#define ASCTXFCON_TXFITLOFF 8
91#define ASCRXFCON_RXFEN 0x0001
92#define ASCRXFCON_RXFFLU 0x0002
93#define ASCRXFCON_RXFITLMASK 0x3F00
94#define ASCRXFCON_RXFITLOFF 8
95#define ASCFSTAT_RXFFLMASK 0x003F
96#define ASCFSTAT_TXFFLMASK 0x3F00
97#define ASCFSTAT_TXFREEMASK 0x3F000000
98#define ASCFSTAT_TXFREEOFF 24
99
100static void lqasc_tx_chars(struct uart_port *port);
101static struct ltq_uart_port *lqasc_port[MAXPORTS];
102static struct uart_driver lqasc_reg;
103
104struct ltq_soc_data {
105 int (*fetch_irq)(struct device *dev, struct ltq_uart_port *ltq_port);
106 int (*request_irq)(struct uart_port *port);
107 void (*free_irq)(struct uart_port *port);
108};
109
110struct ltq_uart_port {
111 struct uart_port port;
112 /* clock used to derive divider */
113 struct clk *freqclk;
114 /* clock gating of the ASC core */
115 struct clk *clk;
116 unsigned int tx_irq;
117 unsigned int rx_irq;
118 unsigned int err_irq;
119 unsigned int common_irq;
120 spinlock_t lock; /* exclusive access for multi core */
121
122 const struct ltq_soc_data *soc;
123};
124
125static inline void asc_update_bits(u32 clear, u32 set, void __iomem *reg)
126{
127 u32 tmp = __raw_readl(reg);
128
129 __raw_writel((tmp & ~clear) | set, reg);
130}
131
132static inline struct
133ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
134{
135 return container_of(port, struct ltq_uart_port, port);
136}
137
138static void
139lqasc_stop_tx(struct uart_port *port)
140{
141 return;
142}
143
144static void
145lqasc_start_tx(struct uart_port *port)
146{
147 unsigned long flags;
148 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
149
150 spin_lock_irqsave(<q_port->lock, flags);
151 lqasc_tx_chars(port);
152 spin_unlock_irqrestore(<q_port->lock, flags);
153 return;
154}
155
156static void
157lqasc_stop_rx(struct uart_port *port)
158{
159 __raw_writel(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
160}
161
162static int
163lqasc_rx_chars(struct uart_port *port)
164{
165 struct tty_port *tport = &port->state->port;
166 unsigned int ch = 0, rsr = 0, fifocnt;
167
168 fifocnt = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
169 ASCFSTAT_RXFFLMASK;
170 while (fifocnt--) {
171 u8 flag = TTY_NORMAL;
172 ch = readb(port->membase + LTQ_ASC_RBUF);
173 rsr = (__raw_readl(port->membase + LTQ_ASC_STATE)
174 & ASCSTATE_ANY) | UART_DUMMY_UER_RX;
175 tty_flip_buffer_push(tport);
176 port->icount.rx++;
177
178 /*
179 * Note that the error handling code is
180 * out of the main execution path
181 */
182 if (rsr & ASCSTATE_ANY) {
183 if (rsr & ASCSTATE_PE) {
184 port->icount.parity++;
185 asc_update_bits(0, ASCWHBSTATE_CLRPE,
186 port->membase + LTQ_ASC_WHBSTATE);
187 } else if (rsr & ASCSTATE_FE) {
188 port->icount.frame++;
189 asc_update_bits(0, ASCWHBSTATE_CLRFE,
190 port->membase + LTQ_ASC_WHBSTATE);
191 }
192 if (rsr & ASCSTATE_ROE) {
193 port->icount.overrun++;
194 asc_update_bits(0, ASCWHBSTATE_CLRROE,
195 port->membase + LTQ_ASC_WHBSTATE);
196 }
197
198 rsr &= port->read_status_mask;
199
200 if (rsr & ASCSTATE_PE)
201 flag = TTY_PARITY;
202 else if (rsr & ASCSTATE_FE)
203 flag = TTY_FRAME;
204 }
205
206 if ((rsr & port->ignore_status_mask) == 0)
207 tty_insert_flip_char(tport, ch, flag);
208
209 if (rsr & ASCSTATE_ROE)
210 /*
211 * Overrun is special, since it's reported
212 * immediately, and doesn't affect the current
213 * character
214 */
215 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
216 }
217
218 if (ch != 0)
219 tty_flip_buffer_push(tport);
220
221 return 0;
222}
223
224static void
225lqasc_tx_chars(struct uart_port *port)
226{
227 struct circ_buf *xmit = &port->state->xmit;
228 if (uart_tx_stopped(port)) {
229 lqasc_stop_tx(port);
230 return;
231 }
232
233 while (((__raw_readl(port->membase + LTQ_ASC_FSTAT) &
234 ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF) != 0) {
235 if (port->x_char) {
236 writeb(port->x_char, port->membase + LTQ_ASC_TBUF);
237 port->icount.tx++;
238 port->x_char = 0;
239 continue;
240 }
241
242 if (uart_circ_empty(xmit))
243 break;
244
245 writeb(port->state->xmit.buf[port->state->xmit.tail],
246 port->membase + LTQ_ASC_TBUF);
247 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
248 port->icount.tx++;
249 }
250
251 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
252 uart_write_wakeup(port);
253}
254
255static irqreturn_t
256lqasc_tx_int(int irq, void *_port)
257{
258 unsigned long flags;
259 struct uart_port *port = (struct uart_port *)_port;
260 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
261
262 spin_lock_irqsave(<q_port->lock, flags);
263 __raw_writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
264 spin_unlock_irqrestore(<q_port->lock, flags);
265 lqasc_start_tx(port);
266 return IRQ_HANDLED;
267}
268
269static irqreturn_t
270lqasc_err_int(int irq, void *_port)
271{
272 unsigned long flags;
273 struct uart_port *port = (struct uart_port *)_port;
274 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
275
276 spin_lock_irqsave(<q_port->lock, flags);
277 /* clear any pending interrupts */
278 asc_update_bits(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
279 ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
280 spin_unlock_irqrestore(<q_port->lock, flags);
281 return IRQ_HANDLED;
282}
283
284static irqreturn_t
285lqasc_rx_int(int irq, void *_port)
286{
287 unsigned long flags;
288 struct uart_port *port = (struct uart_port *)_port;
289 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
290
291 spin_lock_irqsave(<q_port->lock, flags);
292 __raw_writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
293 lqasc_rx_chars(port);
294 spin_unlock_irqrestore(<q_port->lock, flags);
295 return IRQ_HANDLED;
296}
297
298static irqreturn_t lqasc_irq(int irq, void *p)
299{
300 unsigned long flags;
301 u32 stat;
302 struct uart_port *port = p;
303 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
304
305 spin_lock_irqsave(<q_port->lock, flags);
306 stat = readl(port->membase + LTQ_ASC_IRNCR);
307 spin_unlock_irqrestore(<q_port->lock, flags);
308 if (!(stat & ASC_IRNCR_MASK))
309 return IRQ_NONE;
310
311 if (stat & ASC_IRNCR_TIR)
312 lqasc_tx_int(irq, p);
313
314 if (stat & ASC_IRNCR_RIR)
315 lqasc_rx_int(irq, p);
316
317 if (stat & ASC_IRNCR_EIR)
318 lqasc_err_int(irq, p);
319
320 return IRQ_HANDLED;
321}
322
323static unsigned int
324lqasc_tx_empty(struct uart_port *port)
325{
326 int status;
327 status = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
328 ASCFSTAT_TXFFLMASK;
329 return status ? 0 : TIOCSER_TEMT;
330}
331
332static unsigned int
333lqasc_get_mctrl(struct uart_port *port)
334{
335 return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR;
336}
337
338static void
339lqasc_set_mctrl(struct uart_port *port, u_int mctrl)
340{
341}
342
343static void
344lqasc_break_ctl(struct uart_port *port, int break_state)
345{
346}
347
348static int
349lqasc_startup(struct uart_port *port)
350{
351 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
352 int retval;
353 unsigned long flags;
354
355 if (!IS_ERR(ltq_port->clk))
356 clk_prepare_enable(ltq_port->clk);
357 port->uartclk = clk_get_rate(ltq_port->freqclk);
358
359 spin_lock_irqsave(<q_port->lock, flags);
360 asc_update_bits(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
361 port->membase + LTQ_ASC_CLC);
362
363 __raw_writel(0, port->membase + LTQ_ASC_PISEL);
364 __raw_writel(
365 ((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
366 ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
367 port->membase + LTQ_ASC_TXFCON);
368 __raw_writel(
369 ((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
370 | ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
371 port->membase + LTQ_ASC_RXFCON);
372 /* make sure other settings are written to hardware before
373 * setting enable bits
374 */
375 wmb();
376 asc_update_bits(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
377 ASCCON_ROEN, port->membase + LTQ_ASC_CON);
378
379 spin_unlock_irqrestore(<q_port->lock, flags);
380
381 retval = ltq_port->soc->request_irq(port);
382 if (retval)
383 return retval;
384
385 __raw_writel(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
386 port->membase + LTQ_ASC_IRNREN);
387 return retval;
388}
389
390static void
391lqasc_shutdown(struct uart_port *port)
392{
393 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
394 unsigned long flags;
395
396 ltq_port->soc->free_irq(port);
397
398 spin_lock_irqsave(<q_port->lock, flags);
399 __raw_writel(0, port->membase + LTQ_ASC_CON);
400 asc_update_bits(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
401 port->membase + LTQ_ASC_RXFCON);
402 asc_update_bits(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
403 port->membase + LTQ_ASC_TXFCON);
404 spin_unlock_irqrestore(<q_port->lock, flags);
405 if (!IS_ERR(ltq_port->clk))
406 clk_disable_unprepare(ltq_port->clk);
407}
408
409static void
410lqasc_set_termios(struct uart_port *port,
411 struct ktermios *new, struct ktermios *old)
412{
413 unsigned int cflag;
414 unsigned int iflag;
415 unsigned int divisor;
416 unsigned int baud;
417 unsigned int con = 0;
418 unsigned long flags;
419 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
420
421 cflag = new->c_cflag;
422 iflag = new->c_iflag;
423
424 switch (cflag & CSIZE) {
425 case CS7:
426 con = ASCCON_M_7ASYNC;
427 break;
428
429 case CS5:
430 case CS6:
431 default:
432 new->c_cflag &= ~ CSIZE;
433 new->c_cflag |= CS8;
434 con = ASCCON_M_8ASYNC;
435 break;
436 }
437
438 cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
439
440 if (cflag & CSTOPB)
441 con |= ASCCON_STP;
442
443 if (cflag & PARENB) {
444 if (!(cflag & PARODD))
445 con &= ~ASCCON_ODD;
446 else
447 con |= ASCCON_ODD;
448 }
449
450 port->read_status_mask = ASCSTATE_ROE;
451 if (iflag & INPCK)
452 port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
453
454 port->ignore_status_mask = 0;
455 if (iflag & IGNPAR)
456 port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
457
458 if (iflag & IGNBRK) {
459 /*
460 * If we're ignoring parity and break indicators,
461 * ignore overruns too (for real raw support).
462 */
463 if (iflag & IGNPAR)
464 port->ignore_status_mask |= ASCSTATE_ROE;
465 }
466
467 if ((cflag & CREAD) == 0)
468 port->ignore_status_mask |= UART_DUMMY_UER_RX;
469
470 /* set error signals - framing, parity and overrun, enable receiver */
471 con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
472
473 spin_lock_irqsave(<q_port->lock, flags);
474
475 /* set up CON */
476 asc_update_bits(0, con, port->membase + LTQ_ASC_CON);
477
478 /* Set baud rate - take a divider of 2 into account */
479 baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
480 divisor = uart_get_divisor(port, baud);
481 divisor = divisor / 2 - 1;
482
483 /* disable the baudrate generator */
484 asc_update_bits(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
485
486 /* make sure the fractional divider is off */
487 asc_update_bits(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
488
489 /* set up to use divisor of 2 */
490 asc_update_bits(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
491
492 /* now we can write the new baudrate into the register */
493 __raw_writel(divisor, port->membase + LTQ_ASC_BG);
494
495 /* turn the baudrate generator back on */
496 asc_update_bits(0, ASCCON_R, port->membase + LTQ_ASC_CON);
497
498 /* enable rx */
499 __raw_writel(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
500
501 spin_unlock_irqrestore(<q_port->lock, flags);
502
503 /* Don't rewrite B0 */
504 if (tty_termios_baud_rate(new))
505 tty_termios_encode_baud_rate(new, baud, baud);
506
507 uart_update_timeout(port, cflag, baud);
508}
509
510static const char*
511lqasc_type(struct uart_port *port)
512{
513 if (port->type == PORT_LTQ_ASC)
514 return DRVNAME;
515 else
516 return NULL;
517}
518
519static void
520lqasc_release_port(struct uart_port *port)
521{
522 struct platform_device *pdev = to_platform_device(port->dev);
523
524 if (port->flags & UPF_IOREMAP) {
525 devm_iounmap(&pdev->dev, port->membase);
526 port->membase = NULL;
527 }
528}
529
530static int
531lqasc_request_port(struct uart_port *port)
532{
533 struct platform_device *pdev = to_platform_device(port->dev);
534 struct resource *res;
535 int size;
536
537 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
538 if (!res) {
539 dev_err(&pdev->dev, "cannot obtain I/O memory region");
540 return -ENODEV;
541 }
542 size = resource_size(res);
543
544 res = devm_request_mem_region(&pdev->dev, res->start,
545 size, dev_name(&pdev->dev));
546 if (!res) {
547 dev_err(&pdev->dev, "cannot request I/O memory region");
548 return -EBUSY;
549 }
550
551 if (port->flags & UPF_IOREMAP) {
552 port->membase = devm_ioremap(&pdev->dev,
553 port->mapbase, size);
554 if (port->membase == NULL)
555 return -ENOMEM;
556 }
557 return 0;
558}
559
560static void
561lqasc_config_port(struct uart_port *port, int flags)
562{
563 if (flags & UART_CONFIG_TYPE) {
564 port->type = PORT_LTQ_ASC;
565 lqasc_request_port(port);
566 }
567}
568
569static int
570lqasc_verify_port(struct uart_port *port,
571 struct serial_struct *ser)
572{
573 int ret = 0;
574 if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC)
575 ret = -EINVAL;
576 if (ser->irq < 0 || ser->irq >= NR_IRQS)
577 ret = -EINVAL;
578 if (ser->baud_base < 9600)
579 ret = -EINVAL;
580 return ret;
581}
582
583static const struct uart_ops lqasc_pops = {
584 .tx_empty = lqasc_tx_empty,
585 .set_mctrl = lqasc_set_mctrl,
586 .get_mctrl = lqasc_get_mctrl,
587 .stop_tx = lqasc_stop_tx,
588 .start_tx = lqasc_start_tx,
589 .stop_rx = lqasc_stop_rx,
590 .break_ctl = lqasc_break_ctl,
591 .startup = lqasc_startup,
592 .shutdown = lqasc_shutdown,
593 .set_termios = lqasc_set_termios,
594 .type = lqasc_type,
595 .release_port = lqasc_release_port,
596 .request_port = lqasc_request_port,
597 .config_port = lqasc_config_port,
598 .verify_port = lqasc_verify_port,
599};
600
601#ifdef CONFIG_SERIAL_LANTIQ_CONSOLE
602static void
603lqasc_console_putchar(struct uart_port *port, int ch)
604{
605 int fifofree;
606
607 if (!port->membase)
608 return;
609
610 do {
611 fifofree = (__raw_readl(port->membase + LTQ_ASC_FSTAT)
612 & ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF;
613 } while (fifofree == 0);
614 writeb(ch, port->membase + LTQ_ASC_TBUF);
615}
616
617static void lqasc_serial_port_write(struct uart_port *port, const char *s,
618 u_int count)
619{
620 uart_console_write(port, s, count, lqasc_console_putchar);
621}
622
623static void
624lqasc_console_write(struct console *co, const char *s, u_int count)
625{
626 struct ltq_uart_port *ltq_port;
627 unsigned long flags;
628
629 if (co->index >= MAXPORTS)
630 return;
631
632 ltq_port = lqasc_port[co->index];
633 if (!ltq_port)
634 return;
635
636 spin_lock_irqsave(<q_port->lock, flags);
637 lqasc_serial_port_write(<q_port->port, s, count);
638 spin_unlock_irqrestore(<q_port->lock, flags);
639}
640
641static int __init
642lqasc_console_setup(struct console *co, char *options)
643{
644 struct ltq_uart_port *ltq_port;
645 struct uart_port *port;
646 int baud = 115200;
647 int bits = 8;
648 int parity = 'n';
649 int flow = 'n';
650
651 if (co->index >= MAXPORTS)
652 return -ENODEV;
653
654 ltq_port = lqasc_port[co->index];
655 if (!ltq_port)
656 return -ENODEV;
657
658 port = <q_port->port;
659
660 if (!IS_ERR(ltq_port->clk))
661 clk_prepare_enable(ltq_port->clk);
662
663 port->uartclk = clk_get_rate(ltq_port->freqclk);
664
665 if (options)
666 uart_parse_options(options, &baud, &parity, &bits, &flow);
667 return uart_set_options(port, co, baud, parity, bits, flow);
668}
669
670static struct console lqasc_console = {
671 .name = "ttyLTQ",
672 .write = lqasc_console_write,
673 .device = uart_console_device,
674 .setup = lqasc_console_setup,
675 .flags = CON_PRINTBUFFER,
676 .index = -1,
677 .data = &lqasc_reg,
678};
679
680static int __init
681lqasc_console_init(void)
682{
683 register_console(&lqasc_console);
684 return 0;
685}
686console_initcall(lqasc_console_init);
687
688static void lqasc_serial_early_console_write(struct console *co,
689 const char *s,
690 u_int count)
691{
692 struct earlycon_device *dev = co->data;
693
694 lqasc_serial_port_write(&dev->port, s, count);
695}
696
697static int __init
698lqasc_serial_early_console_setup(struct earlycon_device *device,
699 const char *opt)
700{
701 if (!device->port.membase)
702 return -ENODEV;
703
704 device->con->write = lqasc_serial_early_console_write;
705 return 0;
706}
707OF_EARLYCON_DECLARE(lantiq, "lantiq,asc", lqasc_serial_early_console_setup);
708OF_EARLYCON_DECLARE(lantiq, "intel,lgm-asc", lqasc_serial_early_console_setup);
709
710#define LANTIQ_SERIAL_CONSOLE (&lqasc_console)
711
712#else
713
714#define LANTIQ_SERIAL_CONSOLE NULL
715
716#endif /* CONFIG_SERIAL_LANTIQ_CONSOLE */
717
718static struct uart_driver lqasc_reg = {
719 .owner = THIS_MODULE,
720 .driver_name = DRVNAME,
721 .dev_name = "ttyLTQ",
722 .major = 0,
723 .minor = 0,
724 .nr = MAXPORTS,
725 .cons = LANTIQ_SERIAL_CONSOLE,
726};
727
728static int fetch_irq_lantiq(struct device *dev, struct ltq_uart_port *ltq_port)
729{
730 struct uart_port *port = <q_port->port;
731 struct resource irqres[3];
732 int ret;
733
734 ret = of_irq_to_resource_table(dev->of_node, irqres, 3);
735 if (ret != 3) {
736 dev_err(dev,
737 "failed to get IRQs for serial port\n");
738 return -ENODEV;
739 }
740 ltq_port->tx_irq = irqres[0].start;
741 ltq_port->rx_irq = irqres[1].start;
742 ltq_port->err_irq = irqres[2].start;
743 port->irq = irqres[0].start;
744
745 return 0;
746}
747
748static int request_irq_lantiq(struct uart_port *port)
749{
750 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
751 int retval;
752
753 retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
754 0, "asc_tx", port);
755 if (retval) {
756 dev_err(port->dev, "failed to request asc_tx\n");
757 return retval;
758 }
759
760 retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
761 0, "asc_rx", port);
762 if (retval) {
763 dev_err(port->dev, "failed to request asc_rx\n");
764 goto err1;
765 }
766
767 retval = request_irq(ltq_port->err_irq, lqasc_err_int,
768 0, "asc_err", port);
769 if (retval) {
770 dev_err(port->dev, "failed to request asc_err\n");
771 goto err2;
772 }
773 return 0;
774
775err2:
776 free_irq(ltq_port->rx_irq, port);
777err1:
778 free_irq(ltq_port->tx_irq, port);
779 return retval;
780}
781
782static void free_irq_lantiq(struct uart_port *port)
783{
784 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
785
786 free_irq(ltq_port->tx_irq, port);
787 free_irq(ltq_port->rx_irq, port);
788 free_irq(ltq_port->err_irq, port);
789}
790
791static int fetch_irq_intel(struct device *dev, struct ltq_uart_port *ltq_port)
792{
793 struct uart_port *port = <q_port->port;
794 int ret;
795
796 ret = of_irq_get(dev->of_node, 0);
797 if (ret < 0) {
798 dev_err(dev, "failed to fetch IRQ for serial port\n");
799 return ret;
800 }
801 ltq_port->common_irq = ret;
802 port->irq = ret;
803
804 return 0;
805}
806
807static int request_irq_intel(struct uart_port *port)
808{
809 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
810 int retval;
811
812 retval = request_irq(ltq_port->common_irq, lqasc_irq, 0,
813 "asc_irq", port);
814 if (retval)
815 dev_err(port->dev, "failed to request asc_irq\n");
816
817 return retval;
818}
819
820static void free_irq_intel(struct uart_port *port)
821{
822 struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
823
824 free_irq(ltq_port->common_irq, port);
825}
826
827static int lqasc_probe(struct platform_device *pdev)
828{
829 struct device_node *node = pdev->dev.of_node;
830 struct ltq_uart_port *ltq_port;
831 struct uart_port *port;
832 struct resource *mmres;
833 int line;
834 int ret;
835
836 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
837 if (!mmres) {
838 dev_err(&pdev->dev,
839 "failed to get memory for serial port\n");
840 return -ENODEV;
841 }
842
843 ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
844 GFP_KERNEL);
845 if (!ltq_port)
846 return -ENOMEM;
847
848 port = <q_port->port;
849
850 ltq_port->soc = of_device_get_match_data(&pdev->dev);
851 ret = ltq_port->soc->fetch_irq(&pdev->dev, ltq_port);
852 if (ret)
853 return ret;
854
855 /* get serial id */
856 line = of_alias_get_id(node, "serial");
857 if (line < 0) {
858 if (IS_ENABLED(CONFIG_LANTIQ)) {
859 if (mmres->start == CPHYSADDR(LTQ_EARLY_ASC))
860 line = 0;
861 else
862 line = 1;
863 } else {
864 dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
865 line);
866 return line;
867 }
868 }
869
870 if (lqasc_port[line]) {
871 dev_err(&pdev->dev, "port %d already allocated\n", line);
872 return -EBUSY;
873 }
874
875 port->iotype = SERIAL_IO_MEM;
876 port->flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
877 port->ops = &lqasc_pops;
878 port->fifosize = 16;
879 port->type = PORT_LTQ_ASC;
880 port->line = line;
881 port->dev = &pdev->dev;
882 /* unused, just to be backward-compatible */
883 port->mapbase = mmres->start;
884
885 if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
886 ltq_port->freqclk = clk_get_fpi();
887 else
888 ltq_port->freqclk = devm_clk_get(&pdev->dev, "freq");
889
890
891 if (IS_ERR(ltq_port->freqclk)) {
892 pr_err("failed to get fpi clk\n");
893 return -ENOENT;
894 }
895
896 /* not all asc ports have clock gates, lets ignore the return code */
897 if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
898 ltq_port->clk = clk_get(&pdev->dev, NULL);
899 else
900 ltq_port->clk = devm_clk_get(&pdev->dev, "asc");
901
902 spin_lock_init(<q_port->lock);
903 lqasc_port[line] = ltq_port;
904 platform_set_drvdata(pdev, ltq_port);
905
906 ret = uart_add_one_port(&lqasc_reg, port);
907
908 return ret;
909}
910
911static int lqasc_remove(struct platform_device *pdev)
912{
913 struct uart_port *port = platform_get_drvdata(pdev);
914
915 return uart_remove_one_port(&lqasc_reg, port);
916}
917
918static const struct ltq_soc_data soc_data_lantiq = {
919 .fetch_irq = fetch_irq_lantiq,
920 .request_irq = request_irq_lantiq,
921 .free_irq = free_irq_lantiq,
922};
923
924static const struct ltq_soc_data soc_data_intel = {
925 .fetch_irq = fetch_irq_intel,
926 .request_irq = request_irq_intel,
927 .free_irq = free_irq_intel,
928};
929
930static const struct of_device_id ltq_asc_match[] = {
931 { .compatible = "lantiq,asc", .data = &soc_data_lantiq },
932 { .compatible = "intel,lgm-asc", .data = &soc_data_intel },
933 {},
934};
935MODULE_DEVICE_TABLE(of, ltq_asc_match);
936
937static struct platform_driver lqasc_driver = {
938 .probe = lqasc_probe,
939 .remove = lqasc_remove,
940 .driver = {
941 .name = DRVNAME,
942 .of_match_table = ltq_asc_match,
943 },
944};
945
946static int __init
947init_lqasc(void)
948{
949 int ret;
950
951 ret = uart_register_driver(&lqasc_reg);
952 if (ret != 0)
953 return ret;
954
955 ret = platform_driver_register(&lqasc_driver);
956 if (ret != 0)
957 uart_unregister_driver(&lqasc_reg);
958
959 return ret;
960}
961
962static void __exit exit_lqasc(void)
963{
964 platform_driver_unregister(&lqasc_driver);
965 uart_unregister_driver(&lqasc_reg);
966}
967
968module_init(init_lqasc);
969module_exit(exit_lqasc);
970
971MODULE_DESCRIPTION("Serial driver for Lantiq & Intel gateway SoCs");
972MODULE_LICENSE("GPL v2");