xref: /openbmc/linux/drivers/tty/serial/sccnxp.c (revision 8b030a57)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  NXP (Philips) SCC+++(SCN+++) serial driver
4  *
5  *  Copyright (C) 2012 Alexander Shiyan <shc_work@mail.ru>
6  *
7  *  Based on sc26xx.c, by Thomas Bogendörfer (tsbogend@alpha.franken.de)
8  */
9 
10 #if defined(CONFIG_SERIAL_SCCNXP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
11 #define SUPPORT_SYSRQ
12 #endif
13 
14 #include <linux/clk.h>
15 #include <linux/delay.h>
16 #include <linux/err.h>
17 #include <linux/module.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/device.h>
20 #include <linux/console.h>
21 #include <linux/serial_core.h>
22 #include <linux/serial.h>
23 #include <linux/io.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/spinlock.h>
27 #include <linux/platform_device.h>
28 #include <linux/platform_data/serial-sccnxp.h>
29 #include <linux/regulator/consumer.h>
30 
31 #define SCCNXP_NAME			"uart-sccnxp"
32 #define SCCNXP_MAJOR			204
33 #define SCCNXP_MINOR			205
34 
35 #define SCCNXP_MR_REG			(0x00)
36 #	define MR0_BAUD_NORMAL		(0 << 0)
37 #	define MR0_BAUD_EXT1		(1 << 0)
38 #	define MR0_BAUD_EXT2		(5 << 0)
39 #	define MR0_FIFO			(1 << 3)
40 #	define MR0_TXLVL		(1 << 4)
41 #	define MR1_BITS_5		(0 << 0)
42 #	define MR1_BITS_6		(1 << 0)
43 #	define MR1_BITS_7		(2 << 0)
44 #	define MR1_BITS_8		(3 << 0)
45 #	define MR1_PAR_EVN		(0 << 2)
46 #	define MR1_PAR_ODD		(1 << 2)
47 #	define MR1_PAR_NO		(4 << 2)
48 #	define MR2_STOP1		(7 << 0)
49 #	define MR2_STOP2		(0xf << 0)
50 #define SCCNXP_SR_REG			(0x01)
51 #	define SR_RXRDY			(1 << 0)
52 #	define SR_FULL			(1 << 1)
53 #	define SR_TXRDY			(1 << 2)
54 #	define SR_TXEMT			(1 << 3)
55 #	define SR_OVR			(1 << 4)
56 #	define SR_PE			(1 << 5)
57 #	define SR_FE			(1 << 6)
58 #	define SR_BRK			(1 << 7)
59 #define SCCNXP_CSR_REG			(SCCNXP_SR_REG)
60 #	define CSR_TIMER_MODE		(0x0d)
61 #define SCCNXP_CR_REG			(0x02)
62 #	define CR_RX_ENABLE		(1 << 0)
63 #	define CR_RX_DISABLE		(1 << 1)
64 #	define CR_TX_ENABLE		(1 << 2)
65 #	define CR_TX_DISABLE		(1 << 3)
66 #	define CR_CMD_MRPTR1		(0x01 << 4)
67 #	define CR_CMD_RX_RESET		(0x02 << 4)
68 #	define CR_CMD_TX_RESET		(0x03 << 4)
69 #	define CR_CMD_STATUS_RESET	(0x04 << 4)
70 #	define CR_CMD_BREAK_RESET	(0x05 << 4)
71 #	define CR_CMD_START_BREAK	(0x06 << 4)
72 #	define CR_CMD_STOP_BREAK	(0x07 << 4)
73 #	define CR_CMD_MRPTR0		(0x0b << 4)
74 #define SCCNXP_RHR_REG			(0x03)
75 #define SCCNXP_THR_REG			SCCNXP_RHR_REG
76 #define SCCNXP_IPCR_REG			(0x04)
77 #define SCCNXP_ACR_REG			SCCNXP_IPCR_REG
78 #	define ACR_BAUD0		(0 << 7)
79 #	define ACR_BAUD1		(1 << 7)
80 #	define ACR_TIMER_MODE		(6 << 4)
81 #define SCCNXP_ISR_REG			(0x05)
82 #define SCCNXP_IMR_REG			SCCNXP_ISR_REG
83 #	define IMR_TXRDY		(1 << 0)
84 #	define IMR_RXRDY		(1 << 1)
85 #	define ISR_TXRDY(x)		(1 << ((x * 4) + 0))
86 #	define ISR_RXRDY(x)		(1 << ((x * 4) + 1))
87 #define SCCNXP_CTPU_REG			(0x06)
88 #define SCCNXP_CTPL_REG			(0x07)
89 #define SCCNXP_IPR_REG			(0x0d)
90 #define SCCNXP_OPCR_REG			SCCNXP_IPR_REG
91 #define SCCNXP_SOP_REG			(0x0e)
92 #define SCCNXP_START_COUNTER_REG	SCCNXP_SOP_REG
93 #define SCCNXP_ROP_REG			(0x0f)
94 
95 /* Route helpers */
96 #define MCTRL_MASK(sig)			(0xf << (sig))
97 #define MCTRL_IBIT(cfg, sig)		((((cfg) >> (sig)) & 0xf) - LINE_IP0)
98 #define MCTRL_OBIT(cfg, sig)		((((cfg) >> (sig)) & 0xf) - LINE_OP0)
99 
100 #define SCCNXP_HAVE_IO		0x00000001
101 #define SCCNXP_HAVE_MR0		0x00000002
102 
103 struct sccnxp_chip {
104 	const char		*name;
105 	unsigned int		nr;
106 	unsigned long		freq_min;
107 	unsigned long		freq_std;
108 	unsigned long		freq_max;
109 	unsigned int		flags;
110 	unsigned int		fifosize;
111 	/* Time between read/write cycles */
112 	unsigned int		trwd;
113 };
114 
115 struct sccnxp_port {
116 	struct uart_driver	uart;
117 	struct uart_port	port[SCCNXP_MAX_UARTS];
118 	bool			opened[SCCNXP_MAX_UARTS];
119 
120 	int			irq;
121 	u8			imr;
122 
123 	struct sccnxp_chip	*chip;
124 
125 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
126 	struct console		console;
127 #endif
128 
129 	spinlock_t		lock;
130 
131 	bool			poll;
132 	struct timer_list	timer;
133 
134 	struct sccnxp_pdata	pdata;
135 
136 	struct regulator	*regulator;
137 };
138 
139 static const struct sccnxp_chip sc2681 = {
140 	.name		= "SC2681",
141 	.nr		= 2,
142 	.freq_min	= 1000000,
143 	.freq_std	= 3686400,
144 	.freq_max	= 4000000,
145 	.flags		= SCCNXP_HAVE_IO,
146 	.fifosize	= 3,
147 	.trwd		= 200,
148 };
149 
150 static const struct sccnxp_chip sc2691 = {
151 	.name		= "SC2691",
152 	.nr		= 1,
153 	.freq_min	= 1000000,
154 	.freq_std	= 3686400,
155 	.freq_max	= 4000000,
156 	.flags		= 0,
157 	.fifosize	= 3,
158 	.trwd		= 150,
159 };
160 
161 static const struct sccnxp_chip sc2692 = {
162 	.name		= "SC2692",
163 	.nr		= 2,
164 	.freq_min	= 1000000,
165 	.freq_std	= 3686400,
166 	.freq_max	= 4000000,
167 	.flags		= SCCNXP_HAVE_IO,
168 	.fifosize	= 3,
169 	.trwd		= 30,
170 };
171 
172 static const struct sccnxp_chip sc2891 = {
173 	.name		= "SC2891",
174 	.nr		= 1,
175 	.freq_min	= 100000,
176 	.freq_std	= 3686400,
177 	.freq_max	= 8000000,
178 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
179 	.fifosize	= 16,
180 	.trwd		= 27,
181 };
182 
183 static const struct sccnxp_chip sc2892 = {
184 	.name		= "SC2892",
185 	.nr		= 2,
186 	.freq_min	= 100000,
187 	.freq_std	= 3686400,
188 	.freq_max	= 8000000,
189 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
190 	.fifosize	= 16,
191 	.trwd		= 17,
192 };
193 
194 static const struct sccnxp_chip sc28202 = {
195 	.name		= "SC28202",
196 	.nr		= 2,
197 	.freq_min	= 1000000,
198 	.freq_std	= 14745600,
199 	.freq_max	= 50000000,
200 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
201 	.fifosize	= 256,
202 	.trwd		= 10,
203 };
204 
205 static const struct sccnxp_chip sc68681 = {
206 	.name		= "SC68681",
207 	.nr		= 2,
208 	.freq_min	= 1000000,
209 	.freq_std	= 3686400,
210 	.freq_max	= 4000000,
211 	.flags		= SCCNXP_HAVE_IO,
212 	.fifosize	= 3,
213 	.trwd		= 200,
214 };
215 
216 static const struct sccnxp_chip sc68692 = {
217 	.name		= "SC68692",
218 	.nr		= 2,
219 	.freq_min	= 1000000,
220 	.freq_std	= 3686400,
221 	.freq_max	= 4000000,
222 	.flags		= SCCNXP_HAVE_IO,
223 	.fifosize	= 3,
224 	.trwd		= 200,
225 };
226 
227 static u8 sccnxp_read(struct uart_port *port, u8 reg)
228 {
229 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
230 	u8 ret;
231 
232 	ret = readb(port->membase + (reg << port->regshift));
233 
234 	ndelay(s->chip->trwd);
235 
236 	return ret;
237 }
238 
239 static void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
240 {
241 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
242 
243 	writeb(v, port->membase + (reg << port->regshift));
244 
245 	ndelay(s->chip->trwd);
246 }
247 
248 static u8 sccnxp_port_read(struct uart_port *port, u8 reg)
249 {
250 	return sccnxp_read(port, (port->line << 3) + reg);
251 }
252 
253 static void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
254 {
255 	sccnxp_write(port, (port->line << 3) + reg, v);
256 }
257 
258 static int sccnxp_update_best_err(int a, int b, int *besterr)
259 {
260 	int err = abs(a - b);
261 
262 	if (*besterr > err) {
263 		*besterr = err;
264 		return 0;
265 	}
266 
267 	return 1;
268 }
269 
270 static const struct {
271 	u8	csr;
272 	u8	acr;
273 	u8	mr0;
274 	int	baud;
275 } baud_std[] = {
276 	{ 0,	ACR_BAUD0,	MR0_BAUD_NORMAL,	50, },
277 	{ 0,	ACR_BAUD1,	MR0_BAUD_NORMAL,	75, },
278 	{ 1,	ACR_BAUD0,	MR0_BAUD_NORMAL,	110, },
279 	{ 2,	ACR_BAUD0,	MR0_BAUD_NORMAL,	134, },
280 	{ 3,	ACR_BAUD1,	MR0_BAUD_NORMAL,	150, },
281 	{ 3,	ACR_BAUD0,	MR0_BAUD_NORMAL,	200, },
282 	{ 4,	ACR_BAUD0,	MR0_BAUD_NORMAL,	300, },
283 	{ 0,	ACR_BAUD1,	MR0_BAUD_EXT1,		450, },
284 	{ 1,	ACR_BAUD0,	MR0_BAUD_EXT2,		880, },
285 	{ 3,	ACR_BAUD1,	MR0_BAUD_EXT1,		900, },
286 	{ 5,	ACR_BAUD0,	MR0_BAUD_NORMAL,	600, },
287 	{ 7,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1050, },
288 	{ 2,	ACR_BAUD0,	MR0_BAUD_EXT2,		1076, },
289 	{ 6,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1200, },
290 	{ 10,	ACR_BAUD1,	MR0_BAUD_NORMAL,	1800, },
291 	{ 7,	ACR_BAUD1,	MR0_BAUD_NORMAL,	2000, },
292 	{ 8,	ACR_BAUD0,	MR0_BAUD_NORMAL,	2400, },
293 	{ 5,	ACR_BAUD1,	MR0_BAUD_EXT1,		3600, },
294 	{ 9,	ACR_BAUD0,	MR0_BAUD_NORMAL,	4800, },
295 	{ 10,	ACR_BAUD0,	MR0_BAUD_NORMAL,	7200, },
296 	{ 11,	ACR_BAUD0,	MR0_BAUD_NORMAL,	9600, },
297 	{ 8,	ACR_BAUD0,	MR0_BAUD_EXT1,		14400, },
298 	{ 12,	ACR_BAUD1,	MR0_BAUD_NORMAL,	19200, },
299 	{ 9,	ACR_BAUD0,	MR0_BAUD_EXT1,		28800, },
300 	{ 12,	ACR_BAUD0,	MR0_BAUD_NORMAL,	38400, },
301 	{ 11,	ACR_BAUD0,	MR0_BAUD_EXT1,		57600, },
302 	{ 12,	ACR_BAUD1,	MR0_BAUD_EXT1,		115200, },
303 	{ 12,	ACR_BAUD0,	MR0_BAUD_EXT1,		230400, },
304 	{ 0, 0, 0, 0 }
305 };
306 
307 static int sccnxp_set_baud(struct uart_port *port, int baud)
308 {
309 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
310 	int div_std, tmp_baud, bestbaud = INT_MAX, besterr = INT_MAX;
311 	struct sccnxp_chip *chip = s->chip;
312 	u8 i, acr = 0, csr = 0, mr0 = 0;
313 
314 	/* Find divisor to load to the timer preset registers */
315 	div_std = DIV_ROUND_CLOSEST(port->uartclk, 2 * 16 * baud);
316 	if ((div_std >= 2) && (div_std <= 0xffff)) {
317 		bestbaud = DIV_ROUND_CLOSEST(port->uartclk, 2 * 16 * div_std);
318 		sccnxp_update_best_err(baud, bestbaud, &besterr);
319 		csr = CSR_TIMER_MODE;
320 		sccnxp_port_write(port, SCCNXP_CTPU_REG, div_std >> 8);
321 		sccnxp_port_write(port, SCCNXP_CTPL_REG, div_std);
322 		/* Issue start timer/counter command */
323 		sccnxp_port_read(port, SCCNXP_START_COUNTER_REG);
324 	}
325 
326 	/* Find best baud from table */
327 	for (i = 0; baud_std[i].baud && besterr; i++) {
328 		if (baud_std[i].mr0 && !(chip->flags & SCCNXP_HAVE_MR0))
329 			continue;
330 		div_std = DIV_ROUND_CLOSEST(chip->freq_std, baud_std[i].baud);
331 		tmp_baud = DIV_ROUND_CLOSEST(port->uartclk, div_std);
332 		if (!sccnxp_update_best_err(baud, tmp_baud, &besterr)) {
333 			acr = baud_std[i].acr;
334 			csr = baud_std[i].csr;
335 			mr0 = baud_std[i].mr0;
336 			bestbaud = tmp_baud;
337 		}
338 	}
339 
340 	if (chip->flags & SCCNXP_HAVE_MR0) {
341 		/* Enable FIFO, set half level for TX */
342 		mr0 |= MR0_FIFO | MR0_TXLVL;
343 		/* Update MR0 */
344 		sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR0);
345 		sccnxp_port_write(port, SCCNXP_MR_REG, mr0);
346 	}
347 
348 	sccnxp_port_write(port, SCCNXP_ACR_REG, acr | ACR_TIMER_MODE);
349 	sccnxp_port_write(port, SCCNXP_CSR_REG, (csr << 4) | csr);
350 
351 	if (baud != bestbaud)
352 		dev_dbg(port->dev, "Baudrate desired: %i, calculated: %i\n",
353 			baud, bestbaud);
354 
355 	return bestbaud;
356 }
357 
358 static void sccnxp_enable_irq(struct uart_port *port, int mask)
359 {
360 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
361 
362 	s->imr |= mask << (port->line * 4);
363 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
364 }
365 
366 static void sccnxp_disable_irq(struct uart_port *port, int mask)
367 {
368 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
369 
370 	s->imr &= ~(mask << (port->line * 4));
371 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
372 }
373 
374 static void sccnxp_set_bit(struct uart_port *port, int sig, int state)
375 {
376 	u8 bitmask;
377 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
378 
379 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(sig)) {
380 		bitmask = 1 << MCTRL_OBIT(s->pdata.mctrl_cfg[port->line], sig);
381 		if (state)
382 			sccnxp_write(port, SCCNXP_SOP_REG, bitmask);
383 		else
384 			sccnxp_write(port, SCCNXP_ROP_REG, bitmask);
385 	}
386 }
387 
388 static void sccnxp_handle_rx(struct uart_port *port)
389 {
390 	u8 sr;
391 	unsigned int ch, flag;
392 
393 	for (;;) {
394 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
395 		if (!(sr & SR_RXRDY))
396 			break;
397 		sr &= SR_PE | SR_FE | SR_OVR | SR_BRK;
398 
399 		ch = sccnxp_port_read(port, SCCNXP_RHR_REG);
400 
401 		port->icount.rx++;
402 		flag = TTY_NORMAL;
403 
404 		if (unlikely(sr)) {
405 			if (sr & SR_BRK) {
406 				port->icount.brk++;
407 				sccnxp_port_write(port, SCCNXP_CR_REG,
408 						  CR_CMD_BREAK_RESET);
409 				if (uart_handle_break(port))
410 					continue;
411 			} else if (sr & SR_PE)
412 				port->icount.parity++;
413 			else if (sr & SR_FE)
414 				port->icount.frame++;
415 			else if (sr & SR_OVR) {
416 				port->icount.overrun++;
417 				sccnxp_port_write(port, SCCNXP_CR_REG,
418 						  CR_CMD_STATUS_RESET);
419 			}
420 
421 			sr &= port->read_status_mask;
422 			if (sr & SR_BRK)
423 				flag = TTY_BREAK;
424 			else if (sr & SR_PE)
425 				flag = TTY_PARITY;
426 			else if (sr & SR_FE)
427 				flag = TTY_FRAME;
428 			else if (sr & SR_OVR)
429 				flag = TTY_OVERRUN;
430 		}
431 
432 		if (uart_handle_sysrq_char(port, ch))
433 			continue;
434 
435 		if (sr & port->ignore_status_mask)
436 			continue;
437 
438 		uart_insert_char(port, sr, SR_OVR, ch, flag);
439 	}
440 
441 	tty_flip_buffer_push(&port->state->port);
442 }
443 
444 static void sccnxp_handle_tx(struct uart_port *port)
445 {
446 	u8 sr;
447 	struct circ_buf *xmit = &port->state->xmit;
448 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
449 
450 	if (unlikely(port->x_char)) {
451 		sccnxp_port_write(port, SCCNXP_THR_REG, port->x_char);
452 		port->icount.tx++;
453 		port->x_char = 0;
454 		return;
455 	}
456 
457 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
458 		/* Disable TX if FIFO is empty */
459 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXEMT) {
460 			sccnxp_disable_irq(port, IMR_TXRDY);
461 
462 			/* Set direction to input */
463 			if (s->chip->flags & SCCNXP_HAVE_IO)
464 				sccnxp_set_bit(port, DIR_OP, 0);
465 		}
466 		return;
467 	}
468 
469 	while (!uart_circ_empty(xmit)) {
470 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
471 		if (!(sr & SR_TXRDY))
472 			break;
473 
474 		sccnxp_port_write(port, SCCNXP_THR_REG, xmit->buf[xmit->tail]);
475 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
476 		port->icount.tx++;
477 	}
478 
479 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
480 		uart_write_wakeup(port);
481 }
482 
483 static void sccnxp_handle_events(struct sccnxp_port *s)
484 {
485 	int i;
486 	u8 isr;
487 
488 	do {
489 		isr = sccnxp_read(&s->port[0], SCCNXP_ISR_REG);
490 		isr &= s->imr;
491 		if (!isr)
492 			break;
493 
494 		for (i = 0; i < s->uart.nr; i++) {
495 			if (s->opened[i] && (isr & ISR_RXRDY(i)))
496 				sccnxp_handle_rx(&s->port[i]);
497 			if (s->opened[i] && (isr & ISR_TXRDY(i)))
498 				sccnxp_handle_tx(&s->port[i]);
499 		}
500 	} while (1);
501 }
502 
503 static void sccnxp_timer(struct timer_list *t)
504 {
505 	struct sccnxp_port *s = from_timer(s, t, timer);
506 	unsigned long flags;
507 
508 	spin_lock_irqsave(&s->lock, flags);
509 	sccnxp_handle_events(s);
510 	spin_unlock_irqrestore(&s->lock, flags);
511 
512 	mod_timer(&s->timer, jiffies + usecs_to_jiffies(s->pdata.poll_time_us));
513 }
514 
515 static irqreturn_t sccnxp_ist(int irq, void *dev_id)
516 {
517 	struct sccnxp_port *s = (struct sccnxp_port *)dev_id;
518 	unsigned long flags;
519 
520 	spin_lock_irqsave(&s->lock, flags);
521 	sccnxp_handle_events(s);
522 	spin_unlock_irqrestore(&s->lock, flags);
523 
524 	return IRQ_HANDLED;
525 }
526 
527 static void sccnxp_start_tx(struct uart_port *port)
528 {
529 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
530 	unsigned long flags;
531 
532 	spin_lock_irqsave(&s->lock, flags);
533 
534 	/* Set direction to output */
535 	if (s->chip->flags & SCCNXP_HAVE_IO)
536 		sccnxp_set_bit(port, DIR_OP, 1);
537 
538 	sccnxp_enable_irq(port, IMR_TXRDY);
539 
540 	spin_unlock_irqrestore(&s->lock, flags);
541 }
542 
543 static void sccnxp_stop_tx(struct uart_port *port)
544 {
545 	/* Do nothing */
546 }
547 
548 static void sccnxp_stop_rx(struct uart_port *port)
549 {
550 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
551 	unsigned long flags;
552 
553 	spin_lock_irqsave(&s->lock, flags);
554 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE);
555 	spin_unlock_irqrestore(&s->lock, flags);
556 }
557 
558 static unsigned int sccnxp_tx_empty(struct uart_port *port)
559 {
560 	u8 val;
561 	unsigned long flags;
562 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
563 
564 	spin_lock_irqsave(&s->lock, flags);
565 	val = sccnxp_port_read(port, SCCNXP_SR_REG);
566 	spin_unlock_irqrestore(&s->lock, flags);
567 
568 	return (val & SR_TXEMT) ? TIOCSER_TEMT : 0;
569 }
570 
571 static void sccnxp_set_mctrl(struct uart_port *port, unsigned int mctrl)
572 {
573 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
574 	unsigned long flags;
575 
576 	if (!(s->chip->flags & SCCNXP_HAVE_IO))
577 		return;
578 
579 	spin_lock_irqsave(&s->lock, flags);
580 
581 	sccnxp_set_bit(port, DTR_OP, mctrl & TIOCM_DTR);
582 	sccnxp_set_bit(port, RTS_OP, mctrl & TIOCM_RTS);
583 
584 	spin_unlock_irqrestore(&s->lock, flags);
585 }
586 
587 static unsigned int sccnxp_get_mctrl(struct uart_port *port)
588 {
589 	u8 bitmask, ipr;
590 	unsigned long flags;
591 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
592 	unsigned int mctrl = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
593 
594 	if (!(s->chip->flags & SCCNXP_HAVE_IO))
595 		return mctrl;
596 
597 	spin_lock_irqsave(&s->lock, flags);
598 
599 	ipr = ~sccnxp_read(port, SCCNXP_IPCR_REG);
600 
601 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DSR_IP)) {
602 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
603 					  DSR_IP);
604 		mctrl &= ~TIOCM_DSR;
605 		mctrl |= (ipr & bitmask) ? TIOCM_DSR : 0;
606 	}
607 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(CTS_IP)) {
608 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
609 					  CTS_IP);
610 		mctrl &= ~TIOCM_CTS;
611 		mctrl |= (ipr & bitmask) ? TIOCM_CTS : 0;
612 	}
613 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DCD_IP)) {
614 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
615 					  DCD_IP);
616 		mctrl &= ~TIOCM_CAR;
617 		mctrl |= (ipr & bitmask) ? TIOCM_CAR : 0;
618 	}
619 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(RNG_IP)) {
620 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
621 					  RNG_IP);
622 		mctrl &= ~TIOCM_RNG;
623 		mctrl |= (ipr & bitmask) ? TIOCM_RNG : 0;
624 	}
625 
626 	spin_unlock_irqrestore(&s->lock, flags);
627 
628 	return mctrl;
629 }
630 
631 static void sccnxp_break_ctl(struct uart_port *port, int break_state)
632 {
633 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
634 	unsigned long flags;
635 
636 	spin_lock_irqsave(&s->lock, flags);
637 	sccnxp_port_write(port, SCCNXP_CR_REG, break_state ?
638 			  CR_CMD_START_BREAK : CR_CMD_STOP_BREAK);
639 	spin_unlock_irqrestore(&s->lock, flags);
640 }
641 
642 static void sccnxp_set_termios(struct uart_port *port,
643 			       struct ktermios *termios, struct ktermios *old)
644 {
645 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
646 	unsigned long flags;
647 	u8 mr1, mr2;
648 	int baud;
649 
650 	spin_lock_irqsave(&s->lock, flags);
651 
652 	/* Mask termios capabilities we don't support */
653 	termios->c_cflag &= ~CMSPAR;
654 
655 	/* Disable RX & TX, reset break condition, status and FIFOs */
656 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET |
657 					       CR_RX_DISABLE | CR_TX_DISABLE);
658 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
659 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
660 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
661 
662 	/* Word size */
663 	switch (termios->c_cflag & CSIZE) {
664 	case CS5:
665 		mr1 = MR1_BITS_5;
666 		break;
667 	case CS6:
668 		mr1 = MR1_BITS_6;
669 		break;
670 	case CS7:
671 		mr1 = MR1_BITS_7;
672 		break;
673 	case CS8:
674 	default:
675 		mr1 = MR1_BITS_8;
676 		break;
677 	}
678 
679 	/* Parity */
680 	if (termios->c_cflag & PARENB) {
681 		if (termios->c_cflag & PARODD)
682 			mr1 |= MR1_PAR_ODD;
683 	} else
684 		mr1 |= MR1_PAR_NO;
685 
686 	/* Stop bits */
687 	mr2 = (termios->c_cflag & CSTOPB) ? MR2_STOP2 : MR2_STOP1;
688 
689 	/* Update desired format */
690 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR1);
691 	sccnxp_port_write(port, SCCNXP_MR_REG, mr1);
692 	sccnxp_port_write(port, SCCNXP_MR_REG, mr2);
693 
694 	/* Set read status mask */
695 	port->read_status_mask = SR_OVR;
696 	if (termios->c_iflag & INPCK)
697 		port->read_status_mask |= SR_PE | SR_FE;
698 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
699 		port->read_status_mask |= SR_BRK;
700 
701 	/* Set status ignore mask */
702 	port->ignore_status_mask = 0;
703 	if (termios->c_iflag & IGNBRK)
704 		port->ignore_status_mask |= SR_BRK;
705 	if (termios->c_iflag & IGNPAR)
706 		port->ignore_status_mask |= SR_PE;
707 	if (!(termios->c_cflag & CREAD))
708 		port->ignore_status_mask |= SR_PE | SR_OVR | SR_FE | SR_BRK;
709 
710 	/* Setup baudrate */
711 	baud = uart_get_baud_rate(port, termios, old, 50,
712 				  (s->chip->flags & SCCNXP_HAVE_MR0) ?
713 				  230400 : 38400);
714 	baud = sccnxp_set_baud(port, baud);
715 
716 	/* Update timeout according to new baud rate */
717 	uart_update_timeout(port, termios->c_cflag, baud);
718 
719 	/* Report actual baudrate back to core */
720 	if (tty_termios_baud_rate(termios))
721 		tty_termios_encode_baud_rate(termios, baud, baud);
722 
723 	/* Enable RX & TX */
724 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
725 
726 	spin_unlock_irqrestore(&s->lock, flags);
727 }
728 
729 static int sccnxp_startup(struct uart_port *port)
730 {
731 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
732 	unsigned long flags;
733 
734 	spin_lock_irqsave(&s->lock, flags);
735 
736 	if (s->chip->flags & SCCNXP_HAVE_IO) {
737 		/* Outputs are controlled manually */
738 		sccnxp_write(port, SCCNXP_OPCR_REG, 0);
739 	}
740 
741 	/* Reset break condition, status and FIFOs */
742 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET);
743 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
744 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
745 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
746 
747 	/* Enable RX & TX */
748 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
749 
750 	/* Enable RX interrupt */
751 	sccnxp_enable_irq(port, IMR_RXRDY);
752 
753 	s->opened[port->line] = 1;
754 
755 	spin_unlock_irqrestore(&s->lock, flags);
756 
757 	return 0;
758 }
759 
760 static void sccnxp_shutdown(struct uart_port *port)
761 {
762 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
763 	unsigned long flags;
764 
765 	spin_lock_irqsave(&s->lock, flags);
766 
767 	s->opened[port->line] = 0;
768 
769 	/* Disable interrupts */
770 	sccnxp_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
771 
772 	/* Disable TX & RX */
773 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE | CR_TX_DISABLE);
774 
775 	/* Leave direction to input */
776 	if (s->chip->flags & SCCNXP_HAVE_IO)
777 		sccnxp_set_bit(port, DIR_OP, 0);
778 
779 	spin_unlock_irqrestore(&s->lock, flags);
780 }
781 
782 static const char *sccnxp_type(struct uart_port *port)
783 {
784 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
785 
786 	return (port->type == PORT_SC26XX) ? s->chip->name : NULL;
787 }
788 
789 static void sccnxp_release_port(struct uart_port *port)
790 {
791 	/* Do nothing */
792 }
793 
794 static int sccnxp_request_port(struct uart_port *port)
795 {
796 	/* Do nothing */
797 	return 0;
798 }
799 
800 static void sccnxp_config_port(struct uart_port *port, int flags)
801 {
802 	if (flags & UART_CONFIG_TYPE)
803 		port->type = PORT_SC26XX;
804 }
805 
806 static int sccnxp_verify_port(struct uart_port *port, struct serial_struct *s)
807 {
808 	if ((s->type == PORT_UNKNOWN) || (s->type == PORT_SC26XX))
809 		return 0;
810 	if (s->irq == port->irq)
811 		return 0;
812 
813 	return -EINVAL;
814 }
815 
816 static const struct uart_ops sccnxp_ops = {
817 	.tx_empty	= sccnxp_tx_empty,
818 	.set_mctrl	= sccnxp_set_mctrl,
819 	.get_mctrl	= sccnxp_get_mctrl,
820 	.stop_tx	= sccnxp_stop_tx,
821 	.start_tx	= sccnxp_start_tx,
822 	.stop_rx	= sccnxp_stop_rx,
823 	.break_ctl	= sccnxp_break_ctl,
824 	.startup	= sccnxp_startup,
825 	.shutdown	= sccnxp_shutdown,
826 	.set_termios	= sccnxp_set_termios,
827 	.type		= sccnxp_type,
828 	.release_port	= sccnxp_release_port,
829 	.request_port	= sccnxp_request_port,
830 	.config_port	= sccnxp_config_port,
831 	.verify_port	= sccnxp_verify_port,
832 };
833 
834 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
835 static void sccnxp_console_putchar(struct uart_port *port, int c)
836 {
837 	int tryes = 100000;
838 
839 	while (tryes--) {
840 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXRDY) {
841 			sccnxp_port_write(port, SCCNXP_THR_REG, c);
842 			break;
843 		}
844 		barrier();
845 	}
846 }
847 
848 static void sccnxp_console_write(struct console *co, const char *c, unsigned n)
849 {
850 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
851 	struct uart_port *port = &s->port[co->index];
852 	unsigned long flags;
853 
854 	spin_lock_irqsave(&s->lock, flags);
855 	uart_console_write(port, c, n, sccnxp_console_putchar);
856 	spin_unlock_irqrestore(&s->lock, flags);
857 }
858 
859 static int sccnxp_console_setup(struct console *co, char *options)
860 {
861 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
862 	struct uart_port *port = &s->port[(co->index > 0) ? co->index : 0];
863 	int baud = 9600, bits = 8, parity = 'n', flow = 'n';
864 
865 	if (options)
866 		uart_parse_options(options, &baud, &parity, &bits, &flow);
867 
868 	return uart_set_options(port, co, baud, parity, bits, flow);
869 }
870 #endif
871 
872 static const struct platform_device_id sccnxp_id_table[] = {
873 	{ .name = "sc2681",	.driver_data = (kernel_ulong_t)&sc2681, },
874 	{ .name = "sc2691",	.driver_data = (kernel_ulong_t)&sc2691, },
875 	{ .name = "sc2692",	.driver_data = (kernel_ulong_t)&sc2692, },
876 	{ .name = "sc2891",	.driver_data = (kernel_ulong_t)&sc2891, },
877 	{ .name = "sc2892",	.driver_data = (kernel_ulong_t)&sc2892, },
878 	{ .name = "sc28202",	.driver_data = (kernel_ulong_t)&sc28202, },
879 	{ .name = "sc68681",	.driver_data = (kernel_ulong_t)&sc68681, },
880 	{ .name = "sc68692",	.driver_data = (kernel_ulong_t)&sc68692, },
881 	{ }
882 };
883 MODULE_DEVICE_TABLE(platform, sccnxp_id_table);
884 
885 static int sccnxp_probe(struct platform_device *pdev)
886 {
887 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
888 	struct sccnxp_pdata *pdata = dev_get_platdata(&pdev->dev);
889 	int i, ret, uartclk;
890 	struct sccnxp_port *s;
891 	void __iomem *membase;
892 	struct clk *clk;
893 
894 	membase = devm_ioremap_resource(&pdev->dev, res);
895 	if (IS_ERR(membase))
896 		return PTR_ERR(membase);
897 
898 	s = devm_kzalloc(&pdev->dev, sizeof(struct sccnxp_port), GFP_KERNEL);
899 	if (!s) {
900 		dev_err(&pdev->dev, "Error allocating port structure\n");
901 		return -ENOMEM;
902 	}
903 	platform_set_drvdata(pdev, s);
904 
905 	spin_lock_init(&s->lock);
906 
907 	s->chip = (struct sccnxp_chip *)pdev->id_entry->driver_data;
908 
909 	s->regulator = devm_regulator_get(&pdev->dev, "vcc");
910 	if (!IS_ERR(s->regulator)) {
911 		ret = regulator_enable(s->regulator);
912 		if (ret) {
913 			dev_err(&pdev->dev,
914 				"Failed to enable regulator: %i\n", ret);
915 			return ret;
916 		}
917 	} else if (PTR_ERR(s->regulator) == -EPROBE_DEFER)
918 		return -EPROBE_DEFER;
919 
920 	clk = devm_clk_get(&pdev->dev, NULL);
921 	if (IS_ERR(clk)) {
922 		ret = PTR_ERR(clk);
923 		if (ret == -EPROBE_DEFER)
924 			goto err_out;
925 		uartclk = 0;
926 	} else {
927 		ret = clk_prepare_enable(clk);
928 		if (ret)
929 			goto err_out;
930 
931 		ret = devm_add_action_or_reset(&pdev->dev,
932 				(void(*)(void *))clk_disable_unprepare,
933 				clk);
934 		if (ret)
935 			goto err_out;
936 
937 		uartclk = clk_get_rate(clk);
938 	}
939 
940 	if (!uartclk) {
941 		dev_notice(&pdev->dev, "Using default clock frequency\n");
942 		uartclk = s->chip->freq_std;
943 	}
944 
945 	/* Check input frequency */
946 	if ((uartclk < s->chip->freq_min) || (uartclk > s->chip->freq_max)) {
947 		dev_err(&pdev->dev, "Frequency out of bounds\n");
948 		ret = -EINVAL;
949 		goto err_out;
950 	}
951 
952 	if (pdata)
953 		memcpy(&s->pdata, pdata, sizeof(struct sccnxp_pdata));
954 
955 	if (s->pdata.poll_time_us) {
956 		dev_info(&pdev->dev, "Using poll mode, resolution %u usecs\n",
957 			 s->pdata.poll_time_us);
958 		s->poll = 1;
959 	}
960 
961 	if (!s->poll) {
962 		s->irq = platform_get_irq(pdev, 0);
963 		if (s->irq < 0) {
964 			dev_err(&pdev->dev, "Missing irq resource data\n");
965 			ret = -ENXIO;
966 			goto err_out;
967 		}
968 	}
969 
970 	s->uart.owner		= THIS_MODULE;
971 	s->uart.dev_name	= "ttySC";
972 	s->uart.major		= SCCNXP_MAJOR;
973 	s->uart.minor		= SCCNXP_MINOR;
974 	s->uart.nr		= s->chip->nr;
975 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
976 	s->uart.cons		= &s->console;
977 	s->uart.cons->device	= uart_console_device;
978 	s->uart.cons->write	= sccnxp_console_write;
979 	s->uart.cons->setup	= sccnxp_console_setup;
980 	s->uart.cons->flags	= CON_PRINTBUFFER;
981 	s->uart.cons->index	= -1;
982 	s->uart.cons->data	= s;
983 	strcpy(s->uart.cons->name, "ttySC");
984 #endif
985 	ret = uart_register_driver(&s->uart);
986 	if (ret) {
987 		dev_err(&pdev->dev, "Registering UART driver failed\n");
988 		goto err_out;
989 	}
990 
991 	for (i = 0; i < s->uart.nr; i++) {
992 		s->port[i].line		= i;
993 		s->port[i].dev		= &pdev->dev;
994 		s->port[i].irq		= s->irq;
995 		s->port[i].type		= PORT_SC26XX;
996 		s->port[i].fifosize	= s->chip->fifosize;
997 		s->port[i].flags	= UPF_SKIP_TEST | UPF_FIXED_TYPE;
998 		s->port[i].iotype	= UPIO_MEM;
999 		s->port[i].mapbase	= res->start;
1000 		s->port[i].membase	= membase;
1001 		s->port[i].regshift	= s->pdata.reg_shift;
1002 		s->port[i].uartclk	= uartclk;
1003 		s->port[i].ops		= &sccnxp_ops;
1004 		uart_add_one_port(&s->uart, &s->port[i]);
1005 		/* Set direction to input */
1006 		if (s->chip->flags & SCCNXP_HAVE_IO)
1007 			sccnxp_set_bit(&s->port[i], DIR_OP, 0);
1008 	}
1009 
1010 	/* Disable interrupts */
1011 	s->imr = 0;
1012 	sccnxp_write(&s->port[0], SCCNXP_IMR_REG, 0);
1013 
1014 	if (!s->poll) {
1015 		ret = devm_request_threaded_irq(&pdev->dev, s->irq, NULL,
1016 						sccnxp_ist,
1017 						IRQF_TRIGGER_FALLING |
1018 						IRQF_ONESHOT,
1019 						dev_name(&pdev->dev), s);
1020 		if (!ret)
1021 			return 0;
1022 
1023 		dev_err(&pdev->dev, "Unable to reguest IRQ %i\n", s->irq);
1024 	} else {
1025 		timer_setup(&s->timer, sccnxp_timer, 0);
1026 		mod_timer(&s->timer, jiffies +
1027 			  usecs_to_jiffies(s->pdata.poll_time_us));
1028 		return 0;
1029 	}
1030 
1031 	uart_unregister_driver(&s->uart);
1032 err_out:
1033 	if (!IS_ERR(s->regulator))
1034 		regulator_disable(s->regulator);
1035 
1036 	return ret;
1037 }
1038 
1039 static int sccnxp_remove(struct platform_device *pdev)
1040 {
1041 	int i;
1042 	struct sccnxp_port *s = platform_get_drvdata(pdev);
1043 
1044 	if (!s->poll)
1045 		devm_free_irq(&pdev->dev, s->irq, s);
1046 	else
1047 		del_timer_sync(&s->timer);
1048 
1049 	for (i = 0; i < s->uart.nr; i++)
1050 		uart_remove_one_port(&s->uart, &s->port[i]);
1051 
1052 	uart_unregister_driver(&s->uart);
1053 
1054 	if (!IS_ERR(s->regulator))
1055 		return regulator_disable(s->regulator);
1056 
1057 	return 0;
1058 }
1059 
1060 static struct platform_driver sccnxp_uart_driver = {
1061 	.driver = {
1062 		.name	= SCCNXP_NAME,
1063 	},
1064 	.probe		= sccnxp_probe,
1065 	.remove		= sccnxp_remove,
1066 	.id_table	= sccnxp_id_table,
1067 };
1068 module_platform_driver(sccnxp_uart_driver);
1069 
1070 MODULE_LICENSE("GPL v2");
1071 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1072 MODULE_DESCRIPTION("SCCNXP serial driver");
1073