xref: /openbmc/linux/drivers/tty/serial/sccnxp.c (revision 0da85d1e)
1 /*
2  *  NXP (Philips) SCC+++(SCN+++) serial driver
3  *
4  *  Copyright (C) 2012 Alexander Shiyan <shc_work@mail.ru>
5  *
6  *  Based on sc26xx.c, by Thomas Bogendörfer (tsbogend@alpha.franken.de)
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13 
14 #if defined(CONFIG_SERIAL_SCCNXP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
15 #define SUPPORT_SYSRQ
16 #endif
17 
18 #include <linux/clk.h>
19 #include <linux/err.h>
20 #include <linux/module.h>
21 #include <linux/device.h>
22 #include <linux/console.h>
23 #include <linux/serial_core.h>
24 #include <linux/serial.h>
25 #include <linux/io.h>
26 #include <linux/tty.h>
27 #include <linux/tty_flip.h>
28 #include <linux/spinlock.h>
29 #include <linux/platform_device.h>
30 #include <linux/platform_data/serial-sccnxp.h>
31 #include <linux/regulator/consumer.h>
32 
33 #define SCCNXP_NAME			"uart-sccnxp"
34 #define SCCNXP_MAJOR			204
35 #define SCCNXP_MINOR			205
36 
37 #define SCCNXP_MR_REG			(0x00)
38 #	define MR0_BAUD_NORMAL		(0 << 0)
39 #	define MR0_BAUD_EXT1		(1 << 0)
40 #	define MR0_BAUD_EXT2		(5 << 0)
41 #	define MR0_FIFO			(1 << 3)
42 #	define MR0_TXLVL		(1 << 4)
43 #	define MR1_BITS_5		(0 << 0)
44 #	define MR1_BITS_6		(1 << 0)
45 #	define MR1_BITS_7		(2 << 0)
46 #	define MR1_BITS_8		(3 << 0)
47 #	define MR1_PAR_EVN		(0 << 2)
48 #	define MR1_PAR_ODD		(1 << 2)
49 #	define MR1_PAR_NO		(4 << 2)
50 #	define MR2_STOP1		(7 << 0)
51 #	define MR2_STOP2		(0xf << 0)
52 #define SCCNXP_SR_REG			(0x01)
53 #define SCCNXP_CSR_REG			SCCNXP_SR_REG
54 #	define SR_RXRDY			(1 << 0)
55 #	define SR_FULL			(1 << 1)
56 #	define SR_TXRDY			(1 << 2)
57 #	define SR_TXEMT			(1 << 3)
58 #	define SR_OVR			(1 << 4)
59 #	define SR_PE			(1 << 5)
60 #	define SR_FE			(1 << 6)
61 #	define SR_BRK			(1 << 7)
62 #define SCCNXP_CR_REG			(0x02)
63 #	define CR_RX_ENABLE		(1 << 0)
64 #	define CR_RX_DISABLE		(1 << 1)
65 #	define CR_TX_ENABLE		(1 << 2)
66 #	define CR_TX_DISABLE		(1 << 3)
67 #	define CR_CMD_MRPTR1		(0x01 << 4)
68 #	define CR_CMD_RX_RESET		(0x02 << 4)
69 #	define CR_CMD_TX_RESET		(0x03 << 4)
70 #	define CR_CMD_STATUS_RESET	(0x04 << 4)
71 #	define CR_CMD_BREAK_RESET	(0x05 << 4)
72 #	define CR_CMD_START_BREAK	(0x06 << 4)
73 #	define CR_CMD_STOP_BREAK	(0x07 << 4)
74 #	define CR_CMD_MRPTR0		(0x0b << 4)
75 #define SCCNXP_RHR_REG			(0x03)
76 #define SCCNXP_THR_REG			SCCNXP_RHR_REG
77 #define SCCNXP_IPCR_REG			(0x04)
78 #define SCCNXP_ACR_REG			SCCNXP_IPCR_REG
79 #	define ACR_BAUD0		(0 << 7)
80 #	define ACR_BAUD1		(1 << 7)
81 #	define ACR_TIMER_MODE		(6 << 4)
82 #define SCCNXP_ISR_REG			(0x05)
83 #define SCCNXP_IMR_REG			SCCNXP_ISR_REG
84 #	define IMR_TXRDY		(1 << 0)
85 #	define IMR_RXRDY		(1 << 1)
86 #	define ISR_TXRDY(x)		(1 << ((x * 4) + 0))
87 #	define ISR_RXRDY(x)		(1 << ((x * 4) + 1))
88 #define SCCNXP_IPR_REG			(0x0d)
89 #define SCCNXP_OPCR_REG			SCCNXP_IPR_REG
90 #define SCCNXP_SOP_REG			(0x0e)
91 #define SCCNXP_ROP_REG			(0x0f)
92 
93 /* Route helpers */
94 #define MCTRL_MASK(sig)			(0xf << (sig))
95 #define MCTRL_IBIT(cfg, sig)		((((cfg) >> (sig)) & 0xf) - LINE_IP0)
96 #define MCTRL_OBIT(cfg, sig)		((((cfg) >> (sig)) & 0xf) - LINE_OP0)
97 
98 #define SCCNXP_HAVE_IO		0x00000001
99 #define SCCNXP_HAVE_MR0		0x00000002
100 
101 struct sccnxp_chip {
102 	const char		*name;
103 	unsigned int		nr;
104 	unsigned long		freq_min;
105 	unsigned long		freq_std;
106 	unsigned long		freq_max;
107 	unsigned int		flags;
108 	unsigned int		fifosize;
109 };
110 
111 struct sccnxp_port {
112 	struct uart_driver	uart;
113 	struct uart_port	port[SCCNXP_MAX_UARTS];
114 	bool			opened[SCCNXP_MAX_UARTS];
115 
116 	int			irq;
117 	u8			imr;
118 
119 	struct sccnxp_chip	*chip;
120 
121 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
122 	struct console		console;
123 #endif
124 
125 	spinlock_t		lock;
126 
127 	bool			poll;
128 	struct timer_list	timer;
129 
130 	struct sccnxp_pdata	pdata;
131 
132 	struct regulator	*regulator;
133 };
134 
135 static const struct sccnxp_chip sc2681 = {
136 	.name		= "SC2681",
137 	.nr		= 2,
138 	.freq_min	= 1000000,
139 	.freq_std	= 3686400,
140 	.freq_max	= 4000000,
141 	.flags		= SCCNXP_HAVE_IO,
142 	.fifosize	= 3,
143 };
144 
145 static const struct sccnxp_chip sc2691 = {
146 	.name		= "SC2691",
147 	.nr		= 1,
148 	.freq_min	= 1000000,
149 	.freq_std	= 3686400,
150 	.freq_max	= 4000000,
151 	.flags		= 0,
152 	.fifosize	= 3,
153 };
154 
155 static const struct sccnxp_chip sc2692 = {
156 	.name		= "SC2692",
157 	.nr		= 2,
158 	.freq_min	= 1000000,
159 	.freq_std	= 3686400,
160 	.freq_max	= 4000000,
161 	.flags		= SCCNXP_HAVE_IO,
162 	.fifosize	= 3,
163 };
164 
165 static const struct sccnxp_chip sc2891 = {
166 	.name		= "SC2891",
167 	.nr		= 1,
168 	.freq_min	= 100000,
169 	.freq_std	= 3686400,
170 	.freq_max	= 8000000,
171 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
172 	.fifosize	= 16,
173 };
174 
175 static const struct sccnxp_chip sc2892 = {
176 	.name		= "SC2892",
177 	.nr		= 2,
178 	.freq_min	= 100000,
179 	.freq_std	= 3686400,
180 	.freq_max	= 8000000,
181 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
182 	.fifosize	= 16,
183 };
184 
185 static const struct sccnxp_chip sc28202 = {
186 	.name		= "SC28202",
187 	.nr		= 2,
188 	.freq_min	= 1000000,
189 	.freq_std	= 14745600,
190 	.freq_max	= 50000000,
191 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
192 	.fifosize	= 256,
193 };
194 
195 static const struct sccnxp_chip sc68681 = {
196 	.name		= "SC68681",
197 	.nr		= 2,
198 	.freq_min	= 1000000,
199 	.freq_std	= 3686400,
200 	.freq_max	= 4000000,
201 	.flags		= SCCNXP_HAVE_IO,
202 	.fifosize	= 3,
203 };
204 
205 static const struct sccnxp_chip sc68692 = {
206 	.name		= "SC68692",
207 	.nr		= 2,
208 	.freq_min	= 1000000,
209 	.freq_std	= 3686400,
210 	.freq_max	= 4000000,
211 	.flags		= SCCNXP_HAVE_IO,
212 	.fifosize	= 3,
213 };
214 
215 static inline u8 sccnxp_read(struct uart_port *port, u8 reg)
216 {
217 	return readb(port->membase + (reg << port->regshift));
218 }
219 
220 static inline void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
221 {
222 	writeb(v, port->membase + (reg << port->regshift));
223 }
224 
225 static inline u8 sccnxp_port_read(struct uart_port *port, u8 reg)
226 {
227 	return sccnxp_read(port, (port->line << 3) + reg);
228 }
229 
230 static inline void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
231 {
232 	sccnxp_write(port, (port->line << 3) + reg, v);
233 }
234 
235 static int sccnxp_update_best_err(int a, int b, int *besterr)
236 {
237 	int err = abs(a - b);
238 
239 	if ((*besterr < 0) || (*besterr > err)) {
240 		*besterr = err;
241 		return 0;
242 	}
243 
244 	return 1;
245 }
246 
247 static const struct {
248 	u8	csr;
249 	u8	acr;
250 	u8	mr0;
251 	int	baud;
252 } baud_std[] = {
253 	{ 0,	ACR_BAUD0,	MR0_BAUD_NORMAL,	50, },
254 	{ 0,	ACR_BAUD1,	MR0_BAUD_NORMAL,	75, },
255 	{ 1,	ACR_BAUD0,	MR0_BAUD_NORMAL,	110, },
256 	{ 2,	ACR_BAUD0,	MR0_BAUD_NORMAL,	134, },
257 	{ 3,	ACR_BAUD1,	MR0_BAUD_NORMAL,	150, },
258 	{ 3,	ACR_BAUD0,	MR0_BAUD_NORMAL,	200, },
259 	{ 4,	ACR_BAUD0,	MR0_BAUD_NORMAL,	300, },
260 	{ 0,	ACR_BAUD1,	MR0_BAUD_EXT1,		450, },
261 	{ 1,	ACR_BAUD0,	MR0_BAUD_EXT2,		880, },
262 	{ 3,	ACR_BAUD1,	MR0_BAUD_EXT1,		900, },
263 	{ 5,	ACR_BAUD0,	MR0_BAUD_NORMAL,	600, },
264 	{ 7,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1050, },
265 	{ 2,	ACR_BAUD0,	MR0_BAUD_EXT2,		1076, },
266 	{ 6,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1200, },
267 	{ 10,	ACR_BAUD1,	MR0_BAUD_NORMAL,	1800, },
268 	{ 7,	ACR_BAUD1,	MR0_BAUD_NORMAL,	2000, },
269 	{ 8,	ACR_BAUD0,	MR0_BAUD_NORMAL,	2400, },
270 	{ 5,	ACR_BAUD1,	MR0_BAUD_EXT1,		3600, },
271 	{ 9,	ACR_BAUD0,	MR0_BAUD_NORMAL,	4800, },
272 	{ 10,	ACR_BAUD0,	MR0_BAUD_NORMAL,	7200, },
273 	{ 11,	ACR_BAUD0,	MR0_BAUD_NORMAL,	9600, },
274 	{ 8,	ACR_BAUD0,	MR0_BAUD_EXT1,		14400, },
275 	{ 12,	ACR_BAUD1,	MR0_BAUD_NORMAL,	19200, },
276 	{ 9,	ACR_BAUD0,	MR0_BAUD_EXT1,		28800, },
277 	{ 12,	ACR_BAUD0,	MR0_BAUD_NORMAL,	38400, },
278 	{ 11,	ACR_BAUD0,	MR0_BAUD_EXT1,		57600, },
279 	{ 12,	ACR_BAUD1,	MR0_BAUD_EXT1,		115200, },
280 	{ 12,	ACR_BAUD0,	MR0_BAUD_EXT1,		230400, },
281 	{ 0, 0, 0, 0 }
282 };
283 
284 static int sccnxp_set_baud(struct uart_port *port, int baud)
285 {
286 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
287 	int div_std, tmp_baud, bestbaud = baud, besterr = -1;
288 	struct sccnxp_chip *chip = s->chip;
289 	u8 i, acr = 0, csr = 0, mr0 = 0;
290 
291 	/* Find best baud from table */
292 	for (i = 0; baud_std[i].baud && besterr; i++) {
293 		if (baud_std[i].mr0 && !(chip->flags & SCCNXP_HAVE_MR0))
294 			continue;
295 		div_std = DIV_ROUND_CLOSEST(chip->freq_std, baud_std[i].baud);
296 		tmp_baud = DIV_ROUND_CLOSEST(port->uartclk, div_std);
297 		if (!sccnxp_update_best_err(baud, tmp_baud, &besterr)) {
298 			acr = baud_std[i].acr;
299 			csr = baud_std[i].csr;
300 			mr0 = baud_std[i].mr0;
301 			bestbaud = tmp_baud;
302 		}
303 	}
304 
305 	if (chip->flags & SCCNXP_HAVE_MR0) {
306 		/* Enable FIFO, set half level for TX */
307 		mr0 |= MR0_FIFO | MR0_TXLVL;
308 		/* Update MR0 */
309 		sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR0);
310 		sccnxp_port_write(port, SCCNXP_MR_REG, mr0);
311 	}
312 
313 	sccnxp_port_write(port, SCCNXP_ACR_REG, acr | ACR_TIMER_MODE);
314 	sccnxp_port_write(port, SCCNXP_CSR_REG, (csr << 4) | csr);
315 
316 	if (baud != bestbaud)
317 		dev_dbg(port->dev, "Baudrate desired: %i, calculated: %i\n",
318 			baud, bestbaud);
319 
320 	return bestbaud;
321 }
322 
323 static void sccnxp_enable_irq(struct uart_port *port, int mask)
324 {
325 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
326 
327 	s->imr |= mask << (port->line * 4);
328 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
329 }
330 
331 static void sccnxp_disable_irq(struct uart_port *port, int mask)
332 {
333 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
334 
335 	s->imr &= ~(mask << (port->line * 4));
336 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
337 }
338 
339 static void sccnxp_set_bit(struct uart_port *port, int sig, int state)
340 {
341 	u8 bitmask;
342 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
343 
344 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(sig)) {
345 		bitmask = 1 << MCTRL_OBIT(s->pdata.mctrl_cfg[port->line], sig);
346 		if (state)
347 			sccnxp_write(port, SCCNXP_SOP_REG, bitmask);
348 		else
349 			sccnxp_write(port, SCCNXP_ROP_REG, bitmask);
350 	}
351 }
352 
353 static void sccnxp_handle_rx(struct uart_port *port)
354 {
355 	u8 sr;
356 	unsigned int ch, flag;
357 
358 	for (;;) {
359 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
360 		if (!(sr & SR_RXRDY))
361 			break;
362 		sr &= SR_PE | SR_FE | SR_OVR | SR_BRK;
363 
364 		ch = sccnxp_port_read(port, SCCNXP_RHR_REG);
365 
366 		port->icount.rx++;
367 		flag = TTY_NORMAL;
368 
369 		if (unlikely(sr)) {
370 			if (sr & SR_BRK) {
371 				port->icount.brk++;
372 				sccnxp_port_write(port, SCCNXP_CR_REG,
373 						  CR_CMD_BREAK_RESET);
374 				if (uart_handle_break(port))
375 					continue;
376 			} else if (sr & SR_PE)
377 				port->icount.parity++;
378 			else if (sr & SR_FE)
379 				port->icount.frame++;
380 			else if (sr & SR_OVR) {
381 				port->icount.overrun++;
382 				sccnxp_port_write(port, SCCNXP_CR_REG,
383 						  CR_CMD_STATUS_RESET);
384 			}
385 
386 			sr &= port->read_status_mask;
387 			if (sr & SR_BRK)
388 				flag = TTY_BREAK;
389 			else if (sr & SR_PE)
390 				flag = TTY_PARITY;
391 			else if (sr & SR_FE)
392 				flag = TTY_FRAME;
393 			else if (sr & SR_OVR)
394 				flag = TTY_OVERRUN;
395 		}
396 
397 		if (uart_handle_sysrq_char(port, ch))
398 			continue;
399 
400 		if (sr & port->ignore_status_mask)
401 			continue;
402 
403 		uart_insert_char(port, sr, SR_OVR, ch, flag);
404 	}
405 
406 	tty_flip_buffer_push(&port->state->port);
407 }
408 
409 static void sccnxp_handle_tx(struct uart_port *port)
410 {
411 	u8 sr;
412 	struct circ_buf *xmit = &port->state->xmit;
413 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
414 
415 	if (unlikely(port->x_char)) {
416 		sccnxp_port_write(port, SCCNXP_THR_REG, port->x_char);
417 		port->icount.tx++;
418 		port->x_char = 0;
419 		return;
420 	}
421 
422 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
423 		/* Disable TX if FIFO is empty */
424 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXEMT) {
425 			sccnxp_disable_irq(port, IMR_TXRDY);
426 
427 			/* Set direction to input */
428 			if (s->chip->flags & SCCNXP_HAVE_IO)
429 				sccnxp_set_bit(port, DIR_OP, 0);
430 		}
431 		return;
432 	}
433 
434 	while (!uart_circ_empty(xmit)) {
435 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
436 		if (!(sr & SR_TXRDY))
437 			break;
438 
439 		sccnxp_port_write(port, SCCNXP_THR_REG, xmit->buf[xmit->tail]);
440 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
441 		port->icount.tx++;
442 	}
443 
444 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
445 		uart_write_wakeup(port);
446 }
447 
448 static void sccnxp_handle_events(struct sccnxp_port *s)
449 {
450 	int i;
451 	u8 isr;
452 
453 	do {
454 		isr = sccnxp_read(&s->port[0], SCCNXP_ISR_REG);
455 		isr &= s->imr;
456 		if (!isr)
457 			break;
458 
459 		for (i = 0; i < s->uart.nr; i++) {
460 			if (s->opened[i] && (isr & ISR_RXRDY(i)))
461 				sccnxp_handle_rx(&s->port[i]);
462 			if (s->opened[i] && (isr & ISR_TXRDY(i)))
463 				sccnxp_handle_tx(&s->port[i]);
464 		}
465 	} while (1);
466 }
467 
468 static void sccnxp_timer(unsigned long data)
469 {
470 	struct sccnxp_port *s = (struct sccnxp_port *)data;
471 	unsigned long flags;
472 
473 	spin_lock_irqsave(&s->lock, flags);
474 	sccnxp_handle_events(s);
475 	spin_unlock_irqrestore(&s->lock, flags);
476 
477 	mod_timer(&s->timer, jiffies + usecs_to_jiffies(s->pdata.poll_time_us));
478 }
479 
480 static irqreturn_t sccnxp_ist(int irq, void *dev_id)
481 {
482 	struct sccnxp_port *s = (struct sccnxp_port *)dev_id;
483 	unsigned long flags;
484 
485 	spin_lock_irqsave(&s->lock, flags);
486 	sccnxp_handle_events(s);
487 	spin_unlock_irqrestore(&s->lock, flags);
488 
489 	return IRQ_HANDLED;
490 }
491 
492 static void sccnxp_start_tx(struct uart_port *port)
493 {
494 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
495 	unsigned long flags;
496 
497 	spin_lock_irqsave(&s->lock, flags);
498 
499 	/* Set direction to output */
500 	if (s->chip->flags & SCCNXP_HAVE_IO)
501 		sccnxp_set_bit(port, DIR_OP, 1);
502 
503 	sccnxp_enable_irq(port, IMR_TXRDY);
504 
505 	spin_unlock_irqrestore(&s->lock, flags);
506 }
507 
508 static void sccnxp_stop_tx(struct uart_port *port)
509 {
510 	/* Do nothing */
511 }
512 
513 static void sccnxp_stop_rx(struct uart_port *port)
514 {
515 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
516 	unsigned long flags;
517 
518 	spin_lock_irqsave(&s->lock, flags);
519 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE);
520 	spin_unlock_irqrestore(&s->lock, flags);
521 }
522 
523 static unsigned int sccnxp_tx_empty(struct uart_port *port)
524 {
525 	u8 val;
526 	unsigned long flags;
527 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
528 
529 	spin_lock_irqsave(&s->lock, flags);
530 	val = sccnxp_port_read(port, SCCNXP_SR_REG);
531 	spin_unlock_irqrestore(&s->lock, flags);
532 
533 	return (val & SR_TXEMT) ? TIOCSER_TEMT : 0;
534 }
535 
536 static void sccnxp_set_mctrl(struct uart_port *port, unsigned int mctrl)
537 {
538 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
539 	unsigned long flags;
540 
541 	if (!(s->chip->flags & SCCNXP_HAVE_IO))
542 		return;
543 
544 	spin_lock_irqsave(&s->lock, flags);
545 
546 	sccnxp_set_bit(port, DTR_OP, mctrl & TIOCM_DTR);
547 	sccnxp_set_bit(port, RTS_OP, mctrl & TIOCM_RTS);
548 
549 	spin_unlock_irqrestore(&s->lock, flags);
550 }
551 
552 static unsigned int sccnxp_get_mctrl(struct uart_port *port)
553 {
554 	u8 bitmask, ipr;
555 	unsigned long flags;
556 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
557 	unsigned int mctrl = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
558 
559 	if (!(s->chip->flags & SCCNXP_HAVE_IO))
560 		return mctrl;
561 
562 	spin_lock_irqsave(&s->lock, flags);
563 
564 	ipr = ~sccnxp_read(port, SCCNXP_IPCR_REG);
565 
566 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DSR_IP)) {
567 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
568 					  DSR_IP);
569 		mctrl &= ~TIOCM_DSR;
570 		mctrl |= (ipr & bitmask) ? TIOCM_DSR : 0;
571 	}
572 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(CTS_IP)) {
573 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
574 					  CTS_IP);
575 		mctrl &= ~TIOCM_CTS;
576 		mctrl |= (ipr & bitmask) ? TIOCM_CTS : 0;
577 	}
578 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DCD_IP)) {
579 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
580 					  DCD_IP);
581 		mctrl &= ~TIOCM_CAR;
582 		mctrl |= (ipr & bitmask) ? TIOCM_CAR : 0;
583 	}
584 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(RNG_IP)) {
585 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
586 					  RNG_IP);
587 		mctrl &= ~TIOCM_RNG;
588 		mctrl |= (ipr & bitmask) ? TIOCM_RNG : 0;
589 	}
590 
591 	spin_unlock_irqrestore(&s->lock, flags);
592 
593 	return mctrl;
594 }
595 
596 static void sccnxp_break_ctl(struct uart_port *port, int break_state)
597 {
598 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
599 	unsigned long flags;
600 
601 	spin_lock_irqsave(&s->lock, flags);
602 	sccnxp_port_write(port, SCCNXP_CR_REG, break_state ?
603 			  CR_CMD_START_BREAK : CR_CMD_STOP_BREAK);
604 	spin_unlock_irqrestore(&s->lock, flags);
605 }
606 
607 static void sccnxp_set_termios(struct uart_port *port,
608 			       struct ktermios *termios, struct ktermios *old)
609 {
610 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
611 	unsigned long flags;
612 	u8 mr1, mr2;
613 	int baud;
614 
615 	spin_lock_irqsave(&s->lock, flags);
616 
617 	/* Mask termios capabilities we don't support */
618 	termios->c_cflag &= ~CMSPAR;
619 
620 	/* Disable RX & TX, reset break condition, status and FIFOs */
621 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET |
622 					       CR_RX_DISABLE | CR_TX_DISABLE);
623 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
624 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
625 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
626 
627 	/* Word size */
628 	switch (termios->c_cflag & CSIZE) {
629 	case CS5:
630 		mr1 = MR1_BITS_5;
631 		break;
632 	case CS6:
633 		mr1 = MR1_BITS_6;
634 		break;
635 	case CS7:
636 		mr1 = MR1_BITS_7;
637 		break;
638 	case CS8:
639 	default:
640 		mr1 = MR1_BITS_8;
641 		break;
642 	}
643 
644 	/* Parity */
645 	if (termios->c_cflag & PARENB) {
646 		if (termios->c_cflag & PARODD)
647 			mr1 |= MR1_PAR_ODD;
648 	} else
649 		mr1 |= MR1_PAR_NO;
650 
651 	/* Stop bits */
652 	mr2 = (termios->c_cflag & CSTOPB) ? MR2_STOP2 : MR2_STOP1;
653 
654 	/* Update desired format */
655 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR1);
656 	sccnxp_port_write(port, SCCNXP_MR_REG, mr1);
657 	sccnxp_port_write(port, SCCNXP_MR_REG, mr2);
658 
659 	/* Set read status mask */
660 	port->read_status_mask = SR_OVR;
661 	if (termios->c_iflag & INPCK)
662 		port->read_status_mask |= SR_PE | SR_FE;
663 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
664 		port->read_status_mask |= SR_BRK;
665 
666 	/* Set status ignore mask */
667 	port->ignore_status_mask = 0;
668 	if (termios->c_iflag & IGNBRK)
669 		port->ignore_status_mask |= SR_BRK;
670 	if (termios->c_iflag & IGNPAR)
671 		port->ignore_status_mask |= SR_PE;
672 	if (!(termios->c_cflag & CREAD))
673 		port->ignore_status_mask |= SR_PE | SR_OVR | SR_FE | SR_BRK;
674 
675 	/* Setup baudrate */
676 	baud = uart_get_baud_rate(port, termios, old, 50,
677 				  (s->chip->flags & SCCNXP_HAVE_MR0) ?
678 				  230400 : 38400);
679 	baud = sccnxp_set_baud(port, baud);
680 
681 	/* Update timeout according to new baud rate */
682 	uart_update_timeout(port, termios->c_cflag, baud);
683 
684 	/* Report actual baudrate back to core */
685 	if (tty_termios_baud_rate(termios))
686 		tty_termios_encode_baud_rate(termios, baud, baud);
687 
688 	/* Enable RX & TX */
689 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
690 
691 	spin_unlock_irqrestore(&s->lock, flags);
692 }
693 
694 static int sccnxp_startup(struct uart_port *port)
695 {
696 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
697 	unsigned long flags;
698 
699 	spin_lock_irqsave(&s->lock, flags);
700 
701 	if (s->chip->flags & SCCNXP_HAVE_IO) {
702 		/* Outputs are controlled manually */
703 		sccnxp_write(port, SCCNXP_OPCR_REG, 0);
704 	}
705 
706 	/* Reset break condition, status and FIFOs */
707 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET);
708 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
709 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
710 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
711 
712 	/* Enable RX & TX */
713 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
714 
715 	/* Enable RX interrupt */
716 	sccnxp_enable_irq(port, IMR_RXRDY);
717 
718 	s->opened[port->line] = 1;
719 
720 	spin_unlock_irqrestore(&s->lock, flags);
721 
722 	return 0;
723 }
724 
725 static void sccnxp_shutdown(struct uart_port *port)
726 {
727 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
728 	unsigned long flags;
729 
730 	spin_lock_irqsave(&s->lock, flags);
731 
732 	s->opened[port->line] = 0;
733 
734 	/* Disable interrupts */
735 	sccnxp_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
736 
737 	/* Disable TX & RX */
738 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE | CR_TX_DISABLE);
739 
740 	/* Leave direction to input */
741 	if (s->chip->flags & SCCNXP_HAVE_IO)
742 		sccnxp_set_bit(port, DIR_OP, 0);
743 
744 	spin_unlock_irqrestore(&s->lock, flags);
745 }
746 
747 static const char *sccnxp_type(struct uart_port *port)
748 {
749 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
750 
751 	return (port->type == PORT_SC26XX) ? s->chip->name : NULL;
752 }
753 
754 static void sccnxp_release_port(struct uart_port *port)
755 {
756 	/* Do nothing */
757 }
758 
759 static int sccnxp_request_port(struct uart_port *port)
760 {
761 	/* Do nothing */
762 	return 0;
763 }
764 
765 static void sccnxp_config_port(struct uart_port *port, int flags)
766 {
767 	if (flags & UART_CONFIG_TYPE)
768 		port->type = PORT_SC26XX;
769 }
770 
771 static int sccnxp_verify_port(struct uart_port *port, struct serial_struct *s)
772 {
773 	if ((s->type == PORT_UNKNOWN) || (s->type == PORT_SC26XX))
774 		return 0;
775 	if (s->irq == port->irq)
776 		return 0;
777 
778 	return -EINVAL;
779 }
780 
781 static const struct uart_ops sccnxp_ops = {
782 	.tx_empty	= sccnxp_tx_empty,
783 	.set_mctrl	= sccnxp_set_mctrl,
784 	.get_mctrl	= sccnxp_get_mctrl,
785 	.stop_tx	= sccnxp_stop_tx,
786 	.start_tx	= sccnxp_start_tx,
787 	.stop_rx	= sccnxp_stop_rx,
788 	.break_ctl	= sccnxp_break_ctl,
789 	.startup	= sccnxp_startup,
790 	.shutdown	= sccnxp_shutdown,
791 	.set_termios	= sccnxp_set_termios,
792 	.type		= sccnxp_type,
793 	.release_port	= sccnxp_release_port,
794 	.request_port	= sccnxp_request_port,
795 	.config_port	= sccnxp_config_port,
796 	.verify_port	= sccnxp_verify_port,
797 };
798 
799 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
800 static void sccnxp_console_putchar(struct uart_port *port, int c)
801 {
802 	int tryes = 100000;
803 
804 	while (tryes--) {
805 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXRDY) {
806 			sccnxp_port_write(port, SCCNXP_THR_REG, c);
807 			break;
808 		}
809 		barrier();
810 	}
811 }
812 
813 static void sccnxp_console_write(struct console *co, const char *c, unsigned n)
814 {
815 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
816 	struct uart_port *port = &s->port[co->index];
817 	unsigned long flags;
818 
819 	spin_lock_irqsave(&s->lock, flags);
820 	uart_console_write(port, c, n, sccnxp_console_putchar);
821 	spin_unlock_irqrestore(&s->lock, flags);
822 }
823 
824 static int sccnxp_console_setup(struct console *co, char *options)
825 {
826 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
827 	struct uart_port *port = &s->port[(co->index > 0) ? co->index : 0];
828 	int baud = 9600, bits = 8, parity = 'n', flow = 'n';
829 
830 	if (options)
831 		uart_parse_options(options, &baud, &parity, &bits, &flow);
832 
833 	return uart_set_options(port, co, baud, parity, bits, flow);
834 }
835 #endif
836 
837 static const struct platform_device_id sccnxp_id_table[] = {
838 	{ .name = "sc2681",	.driver_data = (kernel_ulong_t)&sc2681, },
839 	{ .name = "sc2691",	.driver_data = (kernel_ulong_t)&sc2691, },
840 	{ .name = "sc2692",	.driver_data = (kernel_ulong_t)&sc2692, },
841 	{ .name = "sc2891",	.driver_data = (kernel_ulong_t)&sc2891, },
842 	{ .name = "sc2892",	.driver_data = (kernel_ulong_t)&sc2892, },
843 	{ .name = "sc28202",	.driver_data = (kernel_ulong_t)&sc28202, },
844 	{ .name = "sc68681",	.driver_data = (kernel_ulong_t)&sc68681, },
845 	{ .name = "sc68692",	.driver_data = (kernel_ulong_t)&sc68692, },
846 	{ }
847 };
848 MODULE_DEVICE_TABLE(platform, sccnxp_id_table);
849 
850 static int sccnxp_probe(struct platform_device *pdev)
851 {
852 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
853 	struct sccnxp_pdata *pdata = dev_get_platdata(&pdev->dev);
854 	int i, ret, uartclk;
855 	struct sccnxp_port *s;
856 	void __iomem *membase;
857 	struct clk *clk;
858 
859 	membase = devm_ioremap_resource(&pdev->dev, res);
860 	if (IS_ERR(membase))
861 		return PTR_ERR(membase);
862 
863 	s = devm_kzalloc(&pdev->dev, sizeof(struct sccnxp_port), GFP_KERNEL);
864 	if (!s) {
865 		dev_err(&pdev->dev, "Error allocating port structure\n");
866 		return -ENOMEM;
867 	}
868 	platform_set_drvdata(pdev, s);
869 
870 	spin_lock_init(&s->lock);
871 
872 	s->chip = (struct sccnxp_chip *)pdev->id_entry->driver_data;
873 
874 	s->regulator = devm_regulator_get(&pdev->dev, "vcc");
875 	if (!IS_ERR(s->regulator)) {
876 		ret = regulator_enable(s->regulator);
877 		if (ret) {
878 			dev_err(&pdev->dev,
879 				"Failed to enable regulator: %i\n", ret);
880 			return ret;
881 		}
882 	} else if (PTR_ERR(s->regulator) == -EPROBE_DEFER)
883 		return -EPROBE_DEFER;
884 
885 	clk = devm_clk_get(&pdev->dev, NULL);
886 	if (IS_ERR(clk)) {
887 		if (PTR_ERR(clk) == -EPROBE_DEFER) {
888 			ret = -EPROBE_DEFER;
889 			goto err_out;
890 		}
891 		dev_notice(&pdev->dev, "Using default clock frequency\n");
892 		uartclk = s->chip->freq_std;
893 	} else
894 		uartclk = clk_get_rate(clk);
895 
896 	/* Check input frequency */
897 	if ((uartclk < s->chip->freq_min) || (uartclk > s->chip->freq_max)) {
898 		dev_err(&pdev->dev, "Frequency out of bounds\n");
899 		ret = -EINVAL;
900 		goto err_out;
901 	}
902 
903 	if (pdata)
904 		memcpy(&s->pdata, pdata, sizeof(struct sccnxp_pdata));
905 
906 	if (s->pdata.poll_time_us) {
907 		dev_info(&pdev->dev, "Using poll mode, resolution %u usecs\n",
908 			 s->pdata.poll_time_us);
909 		s->poll = 1;
910 	}
911 
912 	if (!s->poll) {
913 		s->irq = platform_get_irq(pdev, 0);
914 		if (s->irq < 0) {
915 			dev_err(&pdev->dev, "Missing irq resource data\n");
916 			ret = -ENXIO;
917 			goto err_out;
918 		}
919 	}
920 
921 	s->uart.owner		= THIS_MODULE;
922 	s->uart.dev_name	= "ttySC";
923 	s->uart.major		= SCCNXP_MAJOR;
924 	s->uart.minor		= SCCNXP_MINOR;
925 	s->uart.nr		= s->chip->nr;
926 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
927 	s->uart.cons		= &s->console;
928 	s->uart.cons->device	= uart_console_device;
929 	s->uart.cons->write	= sccnxp_console_write;
930 	s->uart.cons->setup	= sccnxp_console_setup;
931 	s->uart.cons->flags	= CON_PRINTBUFFER;
932 	s->uart.cons->index	= -1;
933 	s->uart.cons->data	= s;
934 	strcpy(s->uart.cons->name, "ttySC");
935 #endif
936 	ret = uart_register_driver(&s->uart);
937 	if (ret) {
938 		dev_err(&pdev->dev, "Registering UART driver failed\n");
939 		goto err_out;
940 	}
941 
942 	for (i = 0; i < s->uart.nr; i++) {
943 		s->port[i].line		= i;
944 		s->port[i].dev		= &pdev->dev;
945 		s->port[i].irq		= s->irq;
946 		s->port[i].type		= PORT_SC26XX;
947 		s->port[i].fifosize	= s->chip->fifosize;
948 		s->port[i].flags	= UPF_SKIP_TEST | UPF_FIXED_TYPE;
949 		s->port[i].iotype	= UPIO_MEM;
950 		s->port[i].mapbase	= res->start;
951 		s->port[i].membase	= membase;
952 		s->port[i].regshift	= s->pdata.reg_shift;
953 		s->port[i].uartclk	= uartclk;
954 		s->port[i].ops		= &sccnxp_ops;
955 		uart_add_one_port(&s->uart, &s->port[i]);
956 		/* Set direction to input */
957 		if (s->chip->flags & SCCNXP_HAVE_IO)
958 			sccnxp_set_bit(&s->port[i], DIR_OP, 0);
959 	}
960 
961 	/* Disable interrupts */
962 	s->imr = 0;
963 	sccnxp_write(&s->port[0], SCCNXP_IMR_REG, 0);
964 
965 	if (!s->poll) {
966 		ret = devm_request_threaded_irq(&pdev->dev, s->irq, NULL,
967 						sccnxp_ist,
968 						IRQF_TRIGGER_FALLING |
969 						IRQF_ONESHOT,
970 						dev_name(&pdev->dev), s);
971 		if (!ret)
972 			return 0;
973 
974 		dev_err(&pdev->dev, "Unable to reguest IRQ %i\n", s->irq);
975 	} else {
976 		init_timer(&s->timer);
977 		setup_timer(&s->timer, sccnxp_timer, (unsigned long)s);
978 		mod_timer(&s->timer, jiffies +
979 			  usecs_to_jiffies(s->pdata.poll_time_us));
980 		return 0;
981 	}
982 
983 	uart_unregister_driver(&s->uart);
984 err_out:
985 	if (!IS_ERR(s->regulator))
986 		return regulator_disable(s->regulator);
987 
988 	return ret;
989 }
990 
991 static int sccnxp_remove(struct platform_device *pdev)
992 {
993 	int i;
994 	struct sccnxp_port *s = platform_get_drvdata(pdev);
995 
996 	if (!s->poll)
997 		devm_free_irq(&pdev->dev, s->irq, s);
998 	else
999 		del_timer_sync(&s->timer);
1000 
1001 	for (i = 0; i < s->uart.nr; i++)
1002 		uart_remove_one_port(&s->uart, &s->port[i]);
1003 
1004 	uart_unregister_driver(&s->uart);
1005 
1006 	if (!IS_ERR(s->regulator))
1007 		return regulator_disable(s->regulator);
1008 
1009 	return 0;
1010 }
1011 
1012 static struct platform_driver sccnxp_uart_driver = {
1013 	.driver = {
1014 		.name	= SCCNXP_NAME,
1015 	},
1016 	.probe		= sccnxp_probe,
1017 	.remove		= sccnxp_remove,
1018 	.id_table	= sccnxp_id_table,
1019 };
1020 module_platform_driver(sccnxp_uart_driver);
1021 
1022 MODULE_LICENSE("GPL v2");
1023 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1024 MODULE_DESCRIPTION("SCCNXP serial driver");
1025