xref: /openbmc/linux/drivers/tty/serial/sccnxp.c (revision bc05aa6e)
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/err.h>
16 #include <linux/module.h>
17 #include <linux/device.h>
18 #include <linux/console.h>
19 #include <linux/serial_core.h>
20 #include <linux/serial.h>
21 #include <linux/io.h>
22 #include <linux/tty.h>
23 #include <linux/tty_flip.h>
24 #include <linux/spinlock.h>
25 #include <linux/platform_device.h>
26 #include <linux/platform_data/serial-sccnxp.h>
27 #include <linux/regulator/consumer.h>
28 
29 #define SCCNXP_NAME			"uart-sccnxp"
30 #define SCCNXP_MAJOR			204
31 #define SCCNXP_MINOR			205
32 
33 #define SCCNXP_MR_REG			(0x00)
34 #	define MR0_BAUD_NORMAL		(0 << 0)
35 #	define MR0_BAUD_EXT1		(1 << 0)
36 #	define MR0_BAUD_EXT2		(5 << 0)
37 #	define MR0_FIFO			(1 << 3)
38 #	define MR0_TXLVL		(1 << 4)
39 #	define MR1_BITS_5		(0 << 0)
40 #	define MR1_BITS_6		(1 << 0)
41 #	define MR1_BITS_7		(2 << 0)
42 #	define MR1_BITS_8		(3 << 0)
43 #	define MR1_PAR_EVN		(0 << 2)
44 #	define MR1_PAR_ODD		(1 << 2)
45 #	define MR1_PAR_NO		(4 << 2)
46 #	define MR2_STOP1		(7 << 0)
47 #	define MR2_STOP2		(0xf << 0)
48 #define SCCNXP_SR_REG			(0x01)
49 #define SCCNXP_CSR_REG			SCCNXP_SR_REG
50 #	define SR_RXRDY			(1 << 0)
51 #	define SR_FULL			(1 << 1)
52 #	define SR_TXRDY			(1 << 2)
53 #	define SR_TXEMT			(1 << 3)
54 #	define SR_OVR			(1 << 4)
55 #	define SR_PE			(1 << 5)
56 #	define SR_FE			(1 << 6)
57 #	define SR_BRK			(1 << 7)
58 #define SCCNXP_CR_REG			(0x02)
59 #	define CR_RX_ENABLE		(1 << 0)
60 #	define CR_RX_DISABLE		(1 << 1)
61 #	define CR_TX_ENABLE		(1 << 2)
62 #	define CR_TX_DISABLE		(1 << 3)
63 #	define CR_CMD_MRPTR1		(0x01 << 4)
64 #	define CR_CMD_RX_RESET		(0x02 << 4)
65 #	define CR_CMD_TX_RESET		(0x03 << 4)
66 #	define CR_CMD_STATUS_RESET	(0x04 << 4)
67 #	define CR_CMD_BREAK_RESET	(0x05 << 4)
68 #	define CR_CMD_START_BREAK	(0x06 << 4)
69 #	define CR_CMD_STOP_BREAK	(0x07 << 4)
70 #	define CR_CMD_MRPTR0		(0x0b << 4)
71 #define SCCNXP_RHR_REG			(0x03)
72 #define SCCNXP_THR_REG			SCCNXP_RHR_REG
73 #define SCCNXP_IPCR_REG			(0x04)
74 #define SCCNXP_ACR_REG			SCCNXP_IPCR_REG
75 #	define ACR_BAUD0		(0 << 7)
76 #	define ACR_BAUD1		(1 << 7)
77 #	define ACR_TIMER_MODE		(6 << 4)
78 #define SCCNXP_ISR_REG			(0x05)
79 #define SCCNXP_IMR_REG			SCCNXP_ISR_REG
80 #	define IMR_TXRDY		(1 << 0)
81 #	define IMR_RXRDY		(1 << 1)
82 #	define ISR_TXRDY(x)		(1 << ((x * 4) + 0))
83 #	define ISR_RXRDY(x)		(1 << ((x * 4) + 1))
84 #define SCCNXP_IPR_REG			(0x0d)
85 #define SCCNXP_OPCR_REG			SCCNXP_IPR_REG
86 #define SCCNXP_SOP_REG			(0x0e)
87 #define SCCNXP_ROP_REG			(0x0f)
88 
89 /* Route helpers */
90 #define MCTRL_MASK(sig)			(0xf << (sig))
91 #define MCTRL_IBIT(cfg, sig)		((((cfg) >> (sig)) & 0xf) - LINE_IP0)
92 #define MCTRL_OBIT(cfg, sig)		((((cfg) >> (sig)) & 0xf) - LINE_OP0)
93 
94 #define SCCNXP_HAVE_IO		0x00000001
95 #define SCCNXP_HAVE_MR0		0x00000002
96 
97 struct sccnxp_chip {
98 	const char		*name;
99 	unsigned int		nr;
100 	unsigned long		freq_min;
101 	unsigned long		freq_std;
102 	unsigned long		freq_max;
103 	unsigned int		flags;
104 	unsigned int		fifosize;
105 };
106 
107 struct sccnxp_port {
108 	struct uart_driver	uart;
109 	struct uart_port	port[SCCNXP_MAX_UARTS];
110 	bool			opened[SCCNXP_MAX_UARTS];
111 
112 	int			irq;
113 	u8			imr;
114 
115 	struct sccnxp_chip	*chip;
116 
117 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
118 	struct console		console;
119 #endif
120 
121 	spinlock_t		lock;
122 
123 	bool			poll;
124 	struct timer_list	timer;
125 
126 	struct sccnxp_pdata	pdata;
127 
128 	struct regulator	*regulator;
129 };
130 
131 static const struct sccnxp_chip sc2681 = {
132 	.name		= "SC2681",
133 	.nr		= 2,
134 	.freq_min	= 1000000,
135 	.freq_std	= 3686400,
136 	.freq_max	= 4000000,
137 	.flags		= SCCNXP_HAVE_IO,
138 	.fifosize	= 3,
139 };
140 
141 static const struct sccnxp_chip sc2691 = {
142 	.name		= "SC2691",
143 	.nr		= 1,
144 	.freq_min	= 1000000,
145 	.freq_std	= 3686400,
146 	.freq_max	= 4000000,
147 	.flags		= 0,
148 	.fifosize	= 3,
149 };
150 
151 static const struct sccnxp_chip sc2692 = {
152 	.name		= "SC2692",
153 	.nr		= 2,
154 	.freq_min	= 1000000,
155 	.freq_std	= 3686400,
156 	.freq_max	= 4000000,
157 	.flags		= SCCNXP_HAVE_IO,
158 	.fifosize	= 3,
159 };
160 
161 static const struct sccnxp_chip sc2891 = {
162 	.name		= "SC2891",
163 	.nr		= 1,
164 	.freq_min	= 100000,
165 	.freq_std	= 3686400,
166 	.freq_max	= 8000000,
167 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
168 	.fifosize	= 16,
169 };
170 
171 static const struct sccnxp_chip sc2892 = {
172 	.name		= "SC2892",
173 	.nr		= 2,
174 	.freq_min	= 100000,
175 	.freq_std	= 3686400,
176 	.freq_max	= 8000000,
177 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
178 	.fifosize	= 16,
179 };
180 
181 static const struct sccnxp_chip sc28202 = {
182 	.name		= "SC28202",
183 	.nr		= 2,
184 	.freq_min	= 1000000,
185 	.freq_std	= 14745600,
186 	.freq_max	= 50000000,
187 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
188 	.fifosize	= 256,
189 };
190 
191 static const struct sccnxp_chip sc68681 = {
192 	.name		= "SC68681",
193 	.nr		= 2,
194 	.freq_min	= 1000000,
195 	.freq_std	= 3686400,
196 	.freq_max	= 4000000,
197 	.flags		= SCCNXP_HAVE_IO,
198 	.fifosize	= 3,
199 };
200 
201 static const struct sccnxp_chip sc68692 = {
202 	.name		= "SC68692",
203 	.nr		= 2,
204 	.freq_min	= 1000000,
205 	.freq_std	= 3686400,
206 	.freq_max	= 4000000,
207 	.flags		= SCCNXP_HAVE_IO,
208 	.fifosize	= 3,
209 };
210 
211 static inline u8 sccnxp_read(struct uart_port *port, u8 reg)
212 {
213 	return readb(port->membase + (reg << port->regshift));
214 }
215 
216 static inline void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
217 {
218 	writeb(v, port->membase + (reg << port->regshift));
219 }
220 
221 static inline u8 sccnxp_port_read(struct uart_port *port, u8 reg)
222 {
223 	return sccnxp_read(port, (port->line << 3) + reg);
224 }
225 
226 static inline void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
227 {
228 	sccnxp_write(port, (port->line << 3) + reg, v);
229 }
230 
231 static int sccnxp_update_best_err(int a, int b, int *besterr)
232 {
233 	int err = abs(a - b);
234 
235 	if ((*besterr < 0) || (*besterr > err)) {
236 		*besterr = err;
237 		return 0;
238 	}
239 
240 	return 1;
241 }
242 
243 static const struct {
244 	u8	csr;
245 	u8	acr;
246 	u8	mr0;
247 	int	baud;
248 } baud_std[] = {
249 	{ 0,	ACR_BAUD0,	MR0_BAUD_NORMAL,	50, },
250 	{ 0,	ACR_BAUD1,	MR0_BAUD_NORMAL,	75, },
251 	{ 1,	ACR_BAUD0,	MR0_BAUD_NORMAL,	110, },
252 	{ 2,	ACR_BAUD0,	MR0_BAUD_NORMAL,	134, },
253 	{ 3,	ACR_BAUD1,	MR0_BAUD_NORMAL,	150, },
254 	{ 3,	ACR_BAUD0,	MR0_BAUD_NORMAL,	200, },
255 	{ 4,	ACR_BAUD0,	MR0_BAUD_NORMAL,	300, },
256 	{ 0,	ACR_BAUD1,	MR0_BAUD_EXT1,		450, },
257 	{ 1,	ACR_BAUD0,	MR0_BAUD_EXT2,		880, },
258 	{ 3,	ACR_BAUD1,	MR0_BAUD_EXT1,		900, },
259 	{ 5,	ACR_BAUD0,	MR0_BAUD_NORMAL,	600, },
260 	{ 7,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1050, },
261 	{ 2,	ACR_BAUD0,	MR0_BAUD_EXT2,		1076, },
262 	{ 6,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1200, },
263 	{ 10,	ACR_BAUD1,	MR0_BAUD_NORMAL,	1800, },
264 	{ 7,	ACR_BAUD1,	MR0_BAUD_NORMAL,	2000, },
265 	{ 8,	ACR_BAUD0,	MR0_BAUD_NORMAL,	2400, },
266 	{ 5,	ACR_BAUD1,	MR0_BAUD_EXT1,		3600, },
267 	{ 9,	ACR_BAUD0,	MR0_BAUD_NORMAL,	4800, },
268 	{ 10,	ACR_BAUD0,	MR0_BAUD_NORMAL,	7200, },
269 	{ 11,	ACR_BAUD0,	MR0_BAUD_NORMAL,	9600, },
270 	{ 8,	ACR_BAUD0,	MR0_BAUD_EXT1,		14400, },
271 	{ 12,	ACR_BAUD1,	MR0_BAUD_NORMAL,	19200, },
272 	{ 9,	ACR_BAUD0,	MR0_BAUD_EXT1,		28800, },
273 	{ 12,	ACR_BAUD0,	MR0_BAUD_NORMAL,	38400, },
274 	{ 11,	ACR_BAUD0,	MR0_BAUD_EXT1,		57600, },
275 	{ 12,	ACR_BAUD1,	MR0_BAUD_EXT1,		115200, },
276 	{ 12,	ACR_BAUD0,	MR0_BAUD_EXT1,		230400, },
277 	{ 0, 0, 0, 0 }
278 };
279 
280 static int sccnxp_set_baud(struct uart_port *port, int baud)
281 {
282 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
283 	int div_std, tmp_baud, bestbaud = baud, besterr = -1;
284 	struct sccnxp_chip *chip = s->chip;
285 	u8 i, acr = 0, csr = 0, mr0 = 0;
286 
287 	/* Find best baud from table */
288 	for (i = 0; baud_std[i].baud && besterr; i++) {
289 		if (baud_std[i].mr0 && !(chip->flags & SCCNXP_HAVE_MR0))
290 			continue;
291 		div_std = DIV_ROUND_CLOSEST(chip->freq_std, baud_std[i].baud);
292 		tmp_baud = DIV_ROUND_CLOSEST(port->uartclk, div_std);
293 		if (!sccnxp_update_best_err(baud, tmp_baud, &besterr)) {
294 			acr = baud_std[i].acr;
295 			csr = baud_std[i].csr;
296 			mr0 = baud_std[i].mr0;
297 			bestbaud = tmp_baud;
298 		}
299 	}
300 
301 	if (chip->flags & SCCNXP_HAVE_MR0) {
302 		/* Enable FIFO, set half level for TX */
303 		mr0 |= MR0_FIFO | MR0_TXLVL;
304 		/* Update MR0 */
305 		sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR0);
306 		sccnxp_port_write(port, SCCNXP_MR_REG, mr0);
307 	}
308 
309 	sccnxp_port_write(port, SCCNXP_ACR_REG, acr | ACR_TIMER_MODE);
310 	sccnxp_port_write(port, SCCNXP_CSR_REG, (csr << 4) | csr);
311 
312 	if (baud != bestbaud)
313 		dev_dbg(port->dev, "Baudrate desired: %i, calculated: %i\n",
314 			baud, bestbaud);
315 
316 	return bestbaud;
317 }
318 
319 static void sccnxp_enable_irq(struct uart_port *port, int mask)
320 {
321 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
322 
323 	s->imr |= mask << (port->line * 4);
324 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
325 }
326 
327 static void sccnxp_disable_irq(struct uart_port *port, int mask)
328 {
329 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
330 
331 	s->imr &= ~(mask << (port->line * 4));
332 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
333 }
334 
335 static void sccnxp_set_bit(struct uart_port *port, int sig, int state)
336 {
337 	u8 bitmask;
338 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
339 
340 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(sig)) {
341 		bitmask = 1 << MCTRL_OBIT(s->pdata.mctrl_cfg[port->line], sig);
342 		if (state)
343 			sccnxp_write(port, SCCNXP_SOP_REG, bitmask);
344 		else
345 			sccnxp_write(port, SCCNXP_ROP_REG, bitmask);
346 	}
347 }
348 
349 static void sccnxp_handle_rx(struct uart_port *port)
350 {
351 	u8 sr;
352 	unsigned int ch, flag;
353 
354 	for (;;) {
355 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
356 		if (!(sr & SR_RXRDY))
357 			break;
358 		sr &= SR_PE | SR_FE | SR_OVR | SR_BRK;
359 
360 		ch = sccnxp_port_read(port, SCCNXP_RHR_REG);
361 
362 		port->icount.rx++;
363 		flag = TTY_NORMAL;
364 
365 		if (unlikely(sr)) {
366 			if (sr & SR_BRK) {
367 				port->icount.brk++;
368 				sccnxp_port_write(port, SCCNXP_CR_REG,
369 						  CR_CMD_BREAK_RESET);
370 				if (uart_handle_break(port))
371 					continue;
372 			} else if (sr & SR_PE)
373 				port->icount.parity++;
374 			else if (sr & SR_FE)
375 				port->icount.frame++;
376 			else if (sr & SR_OVR) {
377 				port->icount.overrun++;
378 				sccnxp_port_write(port, SCCNXP_CR_REG,
379 						  CR_CMD_STATUS_RESET);
380 			}
381 
382 			sr &= port->read_status_mask;
383 			if (sr & SR_BRK)
384 				flag = TTY_BREAK;
385 			else if (sr & SR_PE)
386 				flag = TTY_PARITY;
387 			else if (sr & SR_FE)
388 				flag = TTY_FRAME;
389 			else if (sr & SR_OVR)
390 				flag = TTY_OVERRUN;
391 		}
392 
393 		if (uart_handle_sysrq_char(port, ch))
394 			continue;
395 
396 		if (sr & port->ignore_status_mask)
397 			continue;
398 
399 		uart_insert_char(port, sr, SR_OVR, ch, flag);
400 	}
401 
402 	tty_flip_buffer_push(&port->state->port);
403 }
404 
405 static void sccnxp_handle_tx(struct uart_port *port)
406 {
407 	u8 sr;
408 	struct circ_buf *xmit = &port->state->xmit;
409 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
410 
411 	if (unlikely(port->x_char)) {
412 		sccnxp_port_write(port, SCCNXP_THR_REG, port->x_char);
413 		port->icount.tx++;
414 		port->x_char = 0;
415 		return;
416 	}
417 
418 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
419 		/* Disable TX if FIFO is empty */
420 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXEMT) {
421 			sccnxp_disable_irq(port, IMR_TXRDY);
422 
423 			/* Set direction to input */
424 			if (s->chip->flags & SCCNXP_HAVE_IO)
425 				sccnxp_set_bit(port, DIR_OP, 0);
426 		}
427 		return;
428 	}
429 
430 	while (!uart_circ_empty(xmit)) {
431 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
432 		if (!(sr & SR_TXRDY))
433 			break;
434 
435 		sccnxp_port_write(port, SCCNXP_THR_REG, xmit->buf[xmit->tail]);
436 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
437 		port->icount.tx++;
438 	}
439 
440 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
441 		uart_write_wakeup(port);
442 }
443 
444 static void sccnxp_handle_events(struct sccnxp_port *s)
445 {
446 	int i;
447 	u8 isr;
448 
449 	do {
450 		isr = sccnxp_read(&s->port[0], SCCNXP_ISR_REG);
451 		isr &= s->imr;
452 		if (!isr)
453 			break;
454 
455 		for (i = 0; i < s->uart.nr; i++) {
456 			if (s->opened[i] && (isr & ISR_RXRDY(i)))
457 				sccnxp_handle_rx(&s->port[i]);
458 			if (s->opened[i] && (isr & ISR_TXRDY(i)))
459 				sccnxp_handle_tx(&s->port[i]);
460 		}
461 	} while (1);
462 }
463 
464 static void sccnxp_timer(struct timer_list *t)
465 {
466 	struct sccnxp_port *s = from_timer(s, t, timer);
467 	unsigned long flags;
468 
469 	spin_lock_irqsave(&s->lock, flags);
470 	sccnxp_handle_events(s);
471 	spin_unlock_irqrestore(&s->lock, flags);
472 
473 	mod_timer(&s->timer, jiffies + usecs_to_jiffies(s->pdata.poll_time_us));
474 }
475 
476 static irqreturn_t sccnxp_ist(int irq, void *dev_id)
477 {
478 	struct sccnxp_port *s = (struct sccnxp_port *)dev_id;
479 	unsigned long flags;
480 
481 	spin_lock_irqsave(&s->lock, flags);
482 	sccnxp_handle_events(s);
483 	spin_unlock_irqrestore(&s->lock, flags);
484 
485 	return IRQ_HANDLED;
486 }
487 
488 static void sccnxp_start_tx(struct uart_port *port)
489 {
490 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
491 	unsigned long flags;
492 
493 	spin_lock_irqsave(&s->lock, flags);
494 
495 	/* Set direction to output */
496 	if (s->chip->flags & SCCNXP_HAVE_IO)
497 		sccnxp_set_bit(port, DIR_OP, 1);
498 
499 	sccnxp_enable_irq(port, IMR_TXRDY);
500 
501 	spin_unlock_irqrestore(&s->lock, flags);
502 }
503 
504 static void sccnxp_stop_tx(struct uart_port *port)
505 {
506 	/* Do nothing */
507 }
508 
509 static void sccnxp_stop_rx(struct uart_port *port)
510 {
511 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
512 	unsigned long flags;
513 
514 	spin_lock_irqsave(&s->lock, flags);
515 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE);
516 	spin_unlock_irqrestore(&s->lock, flags);
517 }
518 
519 static unsigned int sccnxp_tx_empty(struct uart_port *port)
520 {
521 	u8 val;
522 	unsigned long flags;
523 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
524 
525 	spin_lock_irqsave(&s->lock, flags);
526 	val = sccnxp_port_read(port, SCCNXP_SR_REG);
527 	spin_unlock_irqrestore(&s->lock, flags);
528 
529 	return (val & SR_TXEMT) ? TIOCSER_TEMT : 0;
530 }
531 
532 static void sccnxp_set_mctrl(struct uart_port *port, unsigned int mctrl)
533 {
534 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
535 	unsigned long flags;
536 
537 	if (!(s->chip->flags & SCCNXP_HAVE_IO))
538 		return;
539 
540 	spin_lock_irqsave(&s->lock, flags);
541 
542 	sccnxp_set_bit(port, DTR_OP, mctrl & TIOCM_DTR);
543 	sccnxp_set_bit(port, RTS_OP, mctrl & TIOCM_RTS);
544 
545 	spin_unlock_irqrestore(&s->lock, flags);
546 }
547 
548 static unsigned int sccnxp_get_mctrl(struct uart_port *port)
549 {
550 	u8 bitmask, ipr;
551 	unsigned long flags;
552 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
553 	unsigned int mctrl = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
554 
555 	if (!(s->chip->flags & SCCNXP_HAVE_IO))
556 		return mctrl;
557 
558 	spin_lock_irqsave(&s->lock, flags);
559 
560 	ipr = ~sccnxp_read(port, SCCNXP_IPCR_REG);
561 
562 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DSR_IP)) {
563 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
564 					  DSR_IP);
565 		mctrl &= ~TIOCM_DSR;
566 		mctrl |= (ipr & bitmask) ? TIOCM_DSR : 0;
567 	}
568 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(CTS_IP)) {
569 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
570 					  CTS_IP);
571 		mctrl &= ~TIOCM_CTS;
572 		mctrl |= (ipr & bitmask) ? TIOCM_CTS : 0;
573 	}
574 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DCD_IP)) {
575 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
576 					  DCD_IP);
577 		mctrl &= ~TIOCM_CAR;
578 		mctrl |= (ipr & bitmask) ? TIOCM_CAR : 0;
579 	}
580 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(RNG_IP)) {
581 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
582 					  RNG_IP);
583 		mctrl &= ~TIOCM_RNG;
584 		mctrl |= (ipr & bitmask) ? TIOCM_RNG : 0;
585 	}
586 
587 	spin_unlock_irqrestore(&s->lock, flags);
588 
589 	return mctrl;
590 }
591 
592 static void sccnxp_break_ctl(struct uart_port *port, int break_state)
593 {
594 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
595 	unsigned long flags;
596 
597 	spin_lock_irqsave(&s->lock, flags);
598 	sccnxp_port_write(port, SCCNXP_CR_REG, break_state ?
599 			  CR_CMD_START_BREAK : CR_CMD_STOP_BREAK);
600 	spin_unlock_irqrestore(&s->lock, flags);
601 }
602 
603 static void sccnxp_set_termios(struct uart_port *port,
604 			       struct ktermios *termios, struct ktermios *old)
605 {
606 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
607 	unsigned long flags;
608 	u8 mr1, mr2;
609 	int baud;
610 
611 	spin_lock_irqsave(&s->lock, flags);
612 
613 	/* Mask termios capabilities we don't support */
614 	termios->c_cflag &= ~CMSPAR;
615 
616 	/* Disable RX & TX, reset break condition, status and FIFOs */
617 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET |
618 					       CR_RX_DISABLE | CR_TX_DISABLE);
619 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
620 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
621 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
622 
623 	/* Word size */
624 	switch (termios->c_cflag & CSIZE) {
625 	case CS5:
626 		mr1 = MR1_BITS_5;
627 		break;
628 	case CS6:
629 		mr1 = MR1_BITS_6;
630 		break;
631 	case CS7:
632 		mr1 = MR1_BITS_7;
633 		break;
634 	case CS8:
635 	default:
636 		mr1 = MR1_BITS_8;
637 		break;
638 	}
639 
640 	/* Parity */
641 	if (termios->c_cflag & PARENB) {
642 		if (termios->c_cflag & PARODD)
643 			mr1 |= MR1_PAR_ODD;
644 	} else
645 		mr1 |= MR1_PAR_NO;
646 
647 	/* Stop bits */
648 	mr2 = (termios->c_cflag & CSTOPB) ? MR2_STOP2 : MR2_STOP1;
649 
650 	/* Update desired format */
651 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR1);
652 	sccnxp_port_write(port, SCCNXP_MR_REG, mr1);
653 	sccnxp_port_write(port, SCCNXP_MR_REG, mr2);
654 
655 	/* Set read status mask */
656 	port->read_status_mask = SR_OVR;
657 	if (termios->c_iflag & INPCK)
658 		port->read_status_mask |= SR_PE | SR_FE;
659 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
660 		port->read_status_mask |= SR_BRK;
661 
662 	/* Set status ignore mask */
663 	port->ignore_status_mask = 0;
664 	if (termios->c_iflag & IGNBRK)
665 		port->ignore_status_mask |= SR_BRK;
666 	if (termios->c_iflag & IGNPAR)
667 		port->ignore_status_mask |= SR_PE;
668 	if (!(termios->c_cflag & CREAD))
669 		port->ignore_status_mask |= SR_PE | SR_OVR | SR_FE | SR_BRK;
670 
671 	/* Setup baudrate */
672 	baud = uart_get_baud_rate(port, termios, old, 50,
673 				  (s->chip->flags & SCCNXP_HAVE_MR0) ?
674 				  230400 : 38400);
675 	baud = sccnxp_set_baud(port, baud);
676 
677 	/* Update timeout according to new baud rate */
678 	uart_update_timeout(port, termios->c_cflag, baud);
679 
680 	/* Report actual baudrate back to core */
681 	if (tty_termios_baud_rate(termios))
682 		tty_termios_encode_baud_rate(termios, baud, baud);
683 
684 	/* Enable RX & TX */
685 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
686 
687 	spin_unlock_irqrestore(&s->lock, flags);
688 }
689 
690 static int sccnxp_startup(struct uart_port *port)
691 {
692 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
693 	unsigned long flags;
694 
695 	spin_lock_irqsave(&s->lock, flags);
696 
697 	if (s->chip->flags & SCCNXP_HAVE_IO) {
698 		/* Outputs are controlled manually */
699 		sccnxp_write(port, SCCNXP_OPCR_REG, 0);
700 	}
701 
702 	/* Reset break condition, status and FIFOs */
703 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET);
704 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
705 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
706 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
707 
708 	/* Enable RX & TX */
709 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
710 
711 	/* Enable RX interrupt */
712 	sccnxp_enable_irq(port, IMR_RXRDY);
713 
714 	s->opened[port->line] = 1;
715 
716 	spin_unlock_irqrestore(&s->lock, flags);
717 
718 	return 0;
719 }
720 
721 static void sccnxp_shutdown(struct uart_port *port)
722 {
723 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
724 	unsigned long flags;
725 
726 	spin_lock_irqsave(&s->lock, flags);
727 
728 	s->opened[port->line] = 0;
729 
730 	/* Disable interrupts */
731 	sccnxp_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
732 
733 	/* Disable TX & RX */
734 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE | CR_TX_DISABLE);
735 
736 	/* Leave direction to input */
737 	if (s->chip->flags & SCCNXP_HAVE_IO)
738 		sccnxp_set_bit(port, DIR_OP, 0);
739 
740 	spin_unlock_irqrestore(&s->lock, flags);
741 }
742 
743 static const char *sccnxp_type(struct uart_port *port)
744 {
745 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
746 
747 	return (port->type == PORT_SC26XX) ? s->chip->name : NULL;
748 }
749 
750 static void sccnxp_release_port(struct uart_port *port)
751 {
752 	/* Do nothing */
753 }
754 
755 static int sccnxp_request_port(struct uart_port *port)
756 {
757 	/* Do nothing */
758 	return 0;
759 }
760 
761 static void sccnxp_config_port(struct uart_port *port, int flags)
762 {
763 	if (flags & UART_CONFIG_TYPE)
764 		port->type = PORT_SC26XX;
765 }
766 
767 static int sccnxp_verify_port(struct uart_port *port, struct serial_struct *s)
768 {
769 	if ((s->type == PORT_UNKNOWN) || (s->type == PORT_SC26XX))
770 		return 0;
771 	if (s->irq == port->irq)
772 		return 0;
773 
774 	return -EINVAL;
775 }
776 
777 static const struct uart_ops sccnxp_ops = {
778 	.tx_empty	= sccnxp_tx_empty,
779 	.set_mctrl	= sccnxp_set_mctrl,
780 	.get_mctrl	= sccnxp_get_mctrl,
781 	.stop_tx	= sccnxp_stop_tx,
782 	.start_tx	= sccnxp_start_tx,
783 	.stop_rx	= sccnxp_stop_rx,
784 	.break_ctl	= sccnxp_break_ctl,
785 	.startup	= sccnxp_startup,
786 	.shutdown	= sccnxp_shutdown,
787 	.set_termios	= sccnxp_set_termios,
788 	.type		= sccnxp_type,
789 	.release_port	= sccnxp_release_port,
790 	.request_port	= sccnxp_request_port,
791 	.config_port	= sccnxp_config_port,
792 	.verify_port	= sccnxp_verify_port,
793 };
794 
795 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
796 static void sccnxp_console_putchar(struct uart_port *port, int c)
797 {
798 	int tryes = 100000;
799 
800 	while (tryes--) {
801 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXRDY) {
802 			sccnxp_port_write(port, SCCNXP_THR_REG, c);
803 			break;
804 		}
805 		barrier();
806 	}
807 }
808 
809 static void sccnxp_console_write(struct console *co, const char *c, unsigned n)
810 {
811 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
812 	struct uart_port *port = &s->port[co->index];
813 	unsigned long flags;
814 
815 	spin_lock_irqsave(&s->lock, flags);
816 	uart_console_write(port, c, n, sccnxp_console_putchar);
817 	spin_unlock_irqrestore(&s->lock, flags);
818 }
819 
820 static int sccnxp_console_setup(struct console *co, char *options)
821 {
822 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
823 	struct uart_port *port = &s->port[(co->index > 0) ? co->index : 0];
824 	int baud = 9600, bits = 8, parity = 'n', flow = 'n';
825 
826 	if (options)
827 		uart_parse_options(options, &baud, &parity, &bits, &flow);
828 
829 	return uart_set_options(port, co, baud, parity, bits, flow);
830 }
831 #endif
832 
833 static const struct platform_device_id sccnxp_id_table[] = {
834 	{ .name = "sc2681",	.driver_data = (kernel_ulong_t)&sc2681, },
835 	{ .name = "sc2691",	.driver_data = (kernel_ulong_t)&sc2691, },
836 	{ .name = "sc2692",	.driver_data = (kernel_ulong_t)&sc2692, },
837 	{ .name = "sc2891",	.driver_data = (kernel_ulong_t)&sc2891, },
838 	{ .name = "sc2892",	.driver_data = (kernel_ulong_t)&sc2892, },
839 	{ .name = "sc28202",	.driver_data = (kernel_ulong_t)&sc28202, },
840 	{ .name = "sc68681",	.driver_data = (kernel_ulong_t)&sc68681, },
841 	{ .name = "sc68692",	.driver_data = (kernel_ulong_t)&sc68692, },
842 	{ }
843 };
844 MODULE_DEVICE_TABLE(platform, sccnxp_id_table);
845 
846 static int sccnxp_probe(struct platform_device *pdev)
847 {
848 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
849 	struct sccnxp_pdata *pdata = dev_get_platdata(&pdev->dev);
850 	int i, ret, uartclk;
851 	struct sccnxp_port *s;
852 	void __iomem *membase;
853 	struct clk *clk;
854 
855 	membase = devm_ioremap_resource(&pdev->dev, res);
856 	if (IS_ERR(membase))
857 		return PTR_ERR(membase);
858 
859 	s = devm_kzalloc(&pdev->dev, sizeof(struct sccnxp_port), GFP_KERNEL);
860 	if (!s) {
861 		dev_err(&pdev->dev, "Error allocating port structure\n");
862 		return -ENOMEM;
863 	}
864 	platform_set_drvdata(pdev, s);
865 
866 	spin_lock_init(&s->lock);
867 
868 	s->chip = (struct sccnxp_chip *)pdev->id_entry->driver_data;
869 
870 	s->regulator = devm_regulator_get(&pdev->dev, "vcc");
871 	if (!IS_ERR(s->regulator)) {
872 		ret = regulator_enable(s->regulator);
873 		if (ret) {
874 			dev_err(&pdev->dev,
875 				"Failed to enable regulator: %i\n", ret);
876 			return ret;
877 		}
878 	} else if (PTR_ERR(s->regulator) == -EPROBE_DEFER)
879 		return -EPROBE_DEFER;
880 
881 	clk = devm_clk_get(&pdev->dev, NULL);
882 	if (IS_ERR(clk)) {
883 		ret = PTR_ERR(clk);
884 		if (ret == -EPROBE_DEFER)
885 			goto err_out;
886 		uartclk = 0;
887 	} else {
888 		ret = clk_prepare_enable(clk);
889 		if (ret)
890 			goto err_out;
891 
892 		ret = devm_add_action_or_reset(&pdev->dev,
893 				(void(*)(void *))clk_disable_unprepare,
894 				clk);
895 		if (ret)
896 			goto err_out;
897 
898 		uartclk = clk_get_rate(clk);
899 	}
900 
901 	if (!uartclk) {
902 		dev_notice(&pdev->dev, "Using default clock frequency\n");
903 		uartclk = s->chip->freq_std;
904 	}
905 
906 	/* Check input frequency */
907 	if ((uartclk < s->chip->freq_min) || (uartclk > s->chip->freq_max)) {
908 		dev_err(&pdev->dev, "Frequency out of bounds\n");
909 		ret = -EINVAL;
910 		goto err_out;
911 	}
912 
913 	if (pdata)
914 		memcpy(&s->pdata, pdata, sizeof(struct sccnxp_pdata));
915 
916 	if (s->pdata.poll_time_us) {
917 		dev_info(&pdev->dev, "Using poll mode, resolution %u usecs\n",
918 			 s->pdata.poll_time_us);
919 		s->poll = 1;
920 	}
921 
922 	if (!s->poll) {
923 		s->irq = platform_get_irq(pdev, 0);
924 		if (s->irq < 0) {
925 			dev_err(&pdev->dev, "Missing irq resource data\n");
926 			ret = -ENXIO;
927 			goto err_out;
928 		}
929 	}
930 
931 	s->uart.owner		= THIS_MODULE;
932 	s->uart.dev_name	= "ttySC";
933 	s->uart.major		= SCCNXP_MAJOR;
934 	s->uart.minor		= SCCNXP_MINOR;
935 	s->uart.nr		= s->chip->nr;
936 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
937 	s->uart.cons		= &s->console;
938 	s->uart.cons->device	= uart_console_device;
939 	s->uart.cons->write	= sccnxp_console_write;
940 	s->uart.cons->setup	= sccnxp_console_setup;
941 	s->uart.cons->flags	= CON_PRINTBUFFER;
942 	s->uart.cons->index	= -1;
943 	s->uart.cons->data	= s;
944 	strcpy(s->uart.cons->name, "ttySC");
945 #endif
946 	ret = uart_register_driver(&s->uart);
947 	if (ret) {
948 		dev_err(&pdev->dev, "Registering UART driver failed\n");
949 		goto err_out;
950 	}
951 
952 	for (i = 0; i < s->uart.nr; i++) {
953 		s->port[i].line		= i;
954 		s->port[i].dev		= &pdev->dev;
955 		s->port[i].irq		= s->irq;
956 		s->port[i].type		= PORT_SC26XX;
957 		s->port[i].fifosize	= s->chip->fifosize;
958 		s->port[i].flags	= UPF_SKIP_TEST | UPF_FIXED_TYPE;
959 		s->port[i].iotype	= UPIO_MEM;
960 		s->port[i].mapbase	= res->start;
961 		s->port[i].membase	= membase;
962 		s->port[i].regshift	= s->pdata.reg_shift;
963 		s->port[i].uartclk	= uartclk;
964 		s->port[i].ops		= &sccnxp_ops;
965 		uart_add_one_port(&s->uart, &s->port[i]);
966 		/* Set direction to input */
967 		if (s->chip->flags & SCCNXP_HAVE_IO)
968 			sccnxp_set_bit(&s->port[i], DIR_OP, 0);
969 	}
970 
971 	/* Disable interrupts */
972 	s->imr = 0;
973 	sccnxp_write(&s->port[0], SCCNXP_IMR_REG, 0);
974 
975 	if (!s->poll) {
976 		ret = devm_request_threaded_irq(&pdev->dev, s->irq, NULL,
977 						sccnxp_ist,
978 						IRQF_TRIGGER_FALLING |
979 						IRQF_ONESHOT,
980 						dev_name(&pdev->dev), s);
981 		if (!ret)
982 			return 0;
983 
984 		dev_err(&pdev->dev, "Unable to reguest IRQ %i\n", s->irq);
985 	} else {
986 		timer_setup(&s->timer, sccnxp_timer, 0);
987 		mod_timer(&s->timer, jiffies +
988 			  usecs_to_jiffies(s->pdata.poll_time_us));
989 		return 0;
990 	}
991 
992 	uart_unregister_driver(&s->uart);
993 err_out:
994 	if (!IS_ERR(s->regulator))
995 		regulator_disable(s->regulator);
996 
997 	return ret;
998 }
999 
1000 static int sccnxp_remove(struct platform_device *pdev)
1001 {
1002 	int i;
1003 	struct sccnxp_port *s = platform_get_drvdata(pdev);
1004 
1005 	if (!s->poll)
1006 		devm_free_irq(&pdev->dev, s->irq, s);
1007 	else
1008 		del_timer_sync(&s->timer);
1009 
1010 	for (i = 0; i < s->uart.nr; i++)
1011 		uart_remove_one_port(&s->uart, &s->port[i]);
1012 
1013 	uart_unregister_driver(&s->uart);
1014 
1015 	if (!IS_ERR(s->regulator))
1016 		return regulator_disable(s->regulator);
1017 
1018 	return 0;
1019 }
1020 
1021 static struct platform_driver sccnxp_uart_driver = {
1022 	.driver = {
1023 		.name	= SCCNXP_NAME,
1024 	},
1025 	.probe		= sccnxp_probe,
1026 	.remove		= sccnxp_remove,
1027 	.id_table	= sccnxp_id_table,
1028 };
1029 module_platform_driver(sccnxp_uart_driver);
1030 
1031 MODULE_LICENSE("GPL v2");
1032 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1033 MODULE_DESCRIPTION("SCCNXP serial driver");
1034