xref: /openbmc/linux/drivers/tty/serial/sccnxp.c (revision 98af278b)
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/mod_devicetable.h>
18 #include <linux/device.h>
19 #include <linux/console.h>
20 #include <linux/serial_core.h>
21 #include <linux/serial.h>
22 #include <linux/io.h>
23 #include <linux/tty.h>
24 #include <linux/tty_flip.h>
25 #include <linux/spinlock.h>
26 #include <linux/platform_device.h>
27 #include <linux/platform_data/serial-sccnxp.h>
28 #include <linux/regulator/consumer.h>
29 
30 #define SCCNXP_NAME			"uart-sccnxp"
31 #define SCCNXP_MAJOR			204
32 #define SCCNXP_MINOR			205
33 
34 #define SCCNXP_MR_REG			(0x00)
35 #	define MR0_BAUD_NORMAL		(0 << 0)
36 #	define MR0_BAUD_EXT1		(1 << 0)
37 #	define MR0_BAUD_EXT2		(5 << 0)
38 #	define MR0_FIFO			(1 << 3)
39 #	define MR0_TXLVL		(1 << 4)
40 #	define MR1_BITS_5		(0 << 0)
41 #	define MR1_BITS_6		(1 << 0)
42 #	define MR1_BITS_7		(2 << 0)
43 #	define MR1_BITS_8		(3 << 0)
44 #	define MR1_PAR_EVN		(0 << 2)
45 #	define MR1_PAR_ODD		(1 << 2)
46 #	define MR1_PAR_NO		(4 << 2)
47 #	define MR2_STOP1		(7 << 0)
48 #	define MR2_STOP2		(0xf << 0)
49 #define SCCNXP_SR_REG			(0x01)
50 #define SCCNXP_CSR_REG			SCCNXP_SR_REG
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_CR_REG			(0x02)
60 #	define CR_RX_ENABLE		(1 << 0)
61 #	define CR_RX_DISABLE		(1 << 1)
62 #	define CR_TX_ENABLE		(1 << 2)
63 #	define CR_TX_DISABLE		(1 << 3)
64 #	define CR_CMD_MRPTR1		(0x01 << 4)
65 #	define CR_CMD_RX_RESET		(0x02 << 4)
66 #	define CR_CMD_TX_RESET		(0x03 << 4)
67 #	define CR_CMD_STATUS_RESET	(0x04 << 4)
68 #	define CR_CMD_BREAK_RESET	(0x05 << 4)
69 #	define CR_CMD_START_BREAK	(0x06 << 4)
70 #	define CR_CMD_STOP_BREAK	(0x07 << 4)
71 #	define CR_CMD_MRPTR0		(0x0b << 4)
72 #define SCCNXP_RHR_REG			(0x03)
73 #define SCCNXP_THR_REG			SCCNXP_RHR_REG
74 #define SCCNXP_IPCR_REG			(0x04)
75 #define SCCNXP_ACR_REG			SCCNXP_IPCR_REG
76 #	define ACR_BAUD0		(0 << 7)
77 #	define ACR_BAUD1		(1 << 7)
78 #	define ACR_TIMER_MODE		(6 << 4)
79 #define SCCNXP_ISR_REG			(0x05)
80 #define SCCNXP_IMR_REG			SCCNXP_ISR_REG
81 #	define IMR_TXRDY		(1 << 0)
82 #	define IMR_RXRDY		(1 << 1)
83 #	define ISR_TXRDY(x)		(1 << ((x * 4) + 0))
84 #	define ISR_RXRDY(x)		(1 << ((x * 4) + 1))
85 #define SCCNXP_IPR_REG			(0x0d)
86 #define SCCNXP_OPCR_REG			SCCNXP_IPR_REG
87 #define SCCNXP_SOP_REG			(0x0e)
88 #define SCCNXP_ROP_REG			(0x0f)
89 
90 /* Route helpers */
91 #define MCTRL_MASK(sig)			(0xf << (sig))
92 #define MCTRL_IBIT(cfg, sig)		((((cfg) >> (sig)) & 0xf) - LINE_IP0)
93 #define MCTRL_OBIT(cfg, sig)		((((cfg) >> (sig)) & 0xf) - LINE_OP0)
94 
95 #define SCCNXP_HAVE_IO		0x00000001
96 #define SCCNXP_HAVE_MR0		0x00000002
97 
98 struct sccnxp_chip {
99 	const char		*name;
100 	unsigned int		nr;
101 	unsigned long		freq_min;
102 	unsigned long		freq_std;
103 	unsigned long		freq_max;
104 	unsigned int		flags;
105 	unsigned int		fifosize;
106 };
107 
108 struct sccnxp_port {
109 	struct uart_driver	uart;
110 	struct uart_port	port[SCCNXP_MAX_UARTS];
111 	bool			opened[SCCNXP_MAX_UARTS];
112 
113 	int			irq;
114 	u8			imr;
115 
116 	struct sccnxp_chip	*chip;
117 
118 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
119 	struct console		console;
120 #endif
121 
122 	spinlock_t		lock;
123 
124 	bool			poll;
125 	struct timer_list	timer;
126 
127 	struct sccnxp_pdata	pdata;
128 
129 	struct regulator	*regulator;
130 };
131 
132 static const struct sccnxp_chip sc2681 = {
133 	.name		= "SC2681",
134 	.nr		= 2,
135 	.freq_min	= 1000000,
136 	.freq_std	= 3686400,
137 	.freq_max	= 4000000,
138 	.flags		= SCCNXP_HAVE_IO,
139 	.fifosize	= 3,
140 };
141 
142 static const struct sccnxp_chip sc2691 = {
143 	.name		= "SC2691",
144 	.nr		= 1,
145 	.freq_min	= 1000000,
146 	.freq_std	= 3686400,
147 	.freq_max	= 4000000,
148 	.flags		= 0,
149 	.fifosize	= 3,
150 };
151 
152 static const struct sccnxp_chip sc2692 = {
153 	.name		= "SC2692",
154 	.nr		= 2,
155 	.freq_min	= 1000000,
156 	.freq_std	= 3686400,
157 	.freq_max	= 4000000,
158 	.flags		= SCCNXP_HAVE_IO,
159 	.fifosize	= 3,
160 };
161 
162 static const struct sccnxp_chip sc2891 = {
163 	.name		= "SC2891",
164 	.nr		= 1,
165 	.freq_min	= 100000,
166 	.freq_std	= 3686400,
167 	.freq_max	= 8000000,
168 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
169 	.fifosize	= 16,
170 };
171 
172 static const struct sccnxp_chip sc2892 = {
173 	.name		= "SC2892",
174 	.nr		= 2,
175 	.freq_min	= 100000,
176 	.freq_std	= 3686400,
177 	.freq_max	= 8000000,
178 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
179 	.fifosize	= 16,
180 };
181 
182 static const struct sccnxp_chip sc28202 = {
183 	.name		= "SC28202",
184 	.nr		= 2,
185 	.freq_min	= 1000000,
186 	.freq_std	= 14745600,
187 	.freq_max	= 50000000,
188 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
189 	.fifosize	= 256,
190 };
191 
192 static const struct sccnxp_chip sc68681 = {
193 	.name		= "SC68681",
194 	.nr		= 2,
195 	.freq_min	= 1000000,
196 	.freq_std	= 3686400,
197 	.freq_max	= 4000000,
198 	.flags		= SCCNXP_HAVE_IO,
199 	.fifosize	= 3,
200 };
201 
202 static const struct sccnxp_chip sc68692 = {
203 	.name		= "SC68692",
204 	.nr		= 2,
205 	.freq_min	= 1000000,
206 	.freq_std	= 3686400,
207 	.freq_max	= 4000000,
208 	.flags		= SCCNXP_HAVE_IO,
209 	.fifosize	= 3,
210 };
211 
212 static inline u8 sccnxp_read(struct uart_port *port, u8 reg)
213 {
214 	return readb(port->membase + (reg << port->regshift));
215 }
216 
217 static inline void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
218 {
219 	writeb(v, port->membase + (reg << port->regshift));
220 }
221 
222 static inline u8 sccnxp_port_read(struct uart_port *port, u8 reg)
223 {
224 	return sccnxp_read(port, (port->line << 3) + reg);
225 }
226 
227 static inline void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
228 {
229 	sccnxp_write(port, (port->line << 3) + reg, v);
230 }
231 
232 static int sccnxp_update_best_err(int a, int b, int *besterr)
233 {
234 	int err = abs(a - b);
235 
236 	if ((*besterr < 0) || (*besterr > err)) {
237 		*besterr = err;
238 		return 0;
239 	}
240 
241 	return 1;
242 }
243 
244 static const struct {
245 	u8	csr;
246 	u8	acr;
247 	u8	mr0;
248 	int	baud;
249 } baud_std[] = {
250 	{ 0,	ACR_BAUD0,	MR0_BAUD_NORMAL,	50, },
251 	{ 0,	ACR_BAUD1,	MR0_BAUD_NORMAL,	75, },
252 	{ 1,	ACR_BAUD0,	MR0_BAUD_NORMAL,	110, },
253 	{ 2,	ACR_BAUD0,	MR0_BAUD_NORMAL,	134, },
254 	{ 3,	ACR_BAUD1,	MR0_BAUD_NORMAL,	150, },
255 	{ 3,	ACR_BAUD0,	MR0_BAUD_NORMAL,	200, },
256 	{ 4,	ACR_BAUD0,	MR0_BAUD_NORMAL,	300, },
257 	{ 0,	ACR_BAUD1,	MR0_BAUD_EXT1,		450, },
258 	{ 1,	ACR_BAUD0,	MR0_BAUD_EXT2,		880, },
259 	{ 3,	ACR_BAUD1,	MR0_BAUD_EXT1,		900, },
260 	{ 5,	ACR_BAUD0,	MR0_BAUD_NORMAL,	600, },
261 	{ 7,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1050, },
262 	{ 2,	ACR_BAUD0,	MR0_BAUD_EXT2,		1076, },
263 	{ 6,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1200, },
264 	{ 10,	ACR_BAUD1,	MR0_BAUD_NORMAL,	1800, },
265 	{ 7,	ACR_BAUD1,	MR0_BAUD_NORMAL,	2000, },
266 	{ 8,	ACR_BAUD0,	MR0_BAUD_NORMAL,	2400, },
267 	{ 5,	ACR_BAUD1,	MR0_BAUD_EXT1,		3600, },
268 	{ 9,	ACR_BAUD0,	MR0_BAUD_NORMAL,	4800, },
269 	{ 10,	ACR_BAUD0,	MR0_BAUD_NORMAL,	7200, },
270 	{ 11,	ACR_BAUD0,	MR0_BAUD_NORMAL,	9600, },
271 	{ 8,	ACR_BAUD0,	MR0_BAUD_EXT1,		14400, },
272 	{ 12,	ACR_BAUD1,	MR0_BAUD_NORMAL,	19200, },
273 	{ 9,	ACR_BAUD0,	MR0_BAUD_EXT1,		28800, },
274 	{ 12,	ACR_BAUD0,	MR0_BAUD_NORMAL,	38400, },
275 	{ 11,	ACR_BAUD0,	MR0_BAUD_EXT1,		57600, },
276 	{ 12,	ACR_BAUD1,	MR0_BAUD_EXT1,		115200, },
277 	{ 12,	ACR_BAUD0,	MR0_BAUD_EXT1,		230400, },
278 	{ 0, 0, 0, 0 }
279 };
280 
281 static int sccnxp_set_baud(struct uart_port *port, int baud)
282 {
283 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
284 	int div_std, tmp_baud, bestbaud = baud, besterr = -1;
285 	struct sccnxp_chip *chip = s->chip;
286 	u8 i, acr = 0, csr = 0, mr0 = 0;
287 
288 	/* Find best baud from table */
289 	for (i = 0; baud_std[i].baud && besterr; i++) {
290 		if (baud_std[i].mr0 && !(chip->flags & SCCNXP_HAVE_MR0))
291 			continue;
292 		div_std = DIV_ROUND_CLOSEST(chip->freq_std, baud_std[i].baud);
293 		tmp_baud = DIV_ROUND_CLOSEST(port->uartclk, div_std);
294 		if (!sccnxp_update_best_err(baud, tmp_baud, &besterr)) {
295 			acr = baud_std[i].acr;
296 			csr = baud_std[i].csr;
297 			mr0 = baud_std[i].mr0;
298 			bestbaud = tmp_baud;
299 		}
300 	}
301 
302 	if (chip->flags & SCCNXP_HAVE_MR0) {
303 		/* Enable FIFO, set half level for TX */
304 		mr0 |= MR0_FIFO | MR0_TXLVL;
305 		/* Update MR0 */
306 		sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR0);
307 		sccnxp_port_write(port, SCCNXP_MR_REG, mr0);
308 	}
309 
310 	sccnxp_port_write(port, SCCNXP_ACR_REG, acr | ACR_TIMER_MODE);
311 	sccnxp_port_write(port, SCCNXP_CSR_REG, (csr << 4) | csr);
312 
313 	if (baud != bestbaud)
314 		dev_dbg(port->dev, "Baudrate desired: %i, calculated: %i\n",
315 			baud, bestbaud);
316 
317 	return bestbaud;
318 }
319 
320 static void sccnxp_enable_irq(struct uart_port *port, int mask)
321 {
322 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
323 
324 	s->imr |= mask << (port->line * 4);
325 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
326 }
327 
328 static void sccnxp_disable_irq(struct uart_port *port, int mask)
329 {
330 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
331 
332 	s->imr &= ~(mask << (port->line * 4));
333 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
334 }
335 
336 static void sccnxp_set_bit(struct uart_port *port, int sig, int state)
337 {
338 	u8 bitmask;
339 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
340 
341 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(sig)) {
342 		bitmask = 1 << MCTRL_OBIT(s->pdata.mctrl_cfg[port->line], sig);
343 		if (state)
344 			sccnxp_write(port, SCCNXP_SOP_REG, bitmask);
345 		else
346 			sccnxp_write(port, SCCNXP_ROP_REG, bitmask);
347 	}
348 }
349 
350 static void sccnxp_handle_rx(struct uart_port *port)
351 {
352 	u8 sr;
353 	unsigned int ch, flag;
354 
355 	for (;;) {
356 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
357 		if (!(sr & SR_RXRDY))
358 			break;
359 		sr &= SR_PE | SR_FE | SR_OVR | SR_BRK;
360 
361 		ch = sccnxp_port_read(port, SCCNXP_RHR_REG);
362 
363 		port->icount.rx++;
364 		flag = TTY_NORMAL;
365 
366 		if (unlikely(sr)) {
367 			if (sr & SR_BRK) {
368 				port->icount.brk++;
369 				sccnxp_port_write(port, SCCNXP_CR_REG,
370 						  CR_CMD_BREAK_RESET);
371 				if (uart_handle_break(port))
372 					continue;
373 			} else if (sr & SR_PE)
374 				port->icount.parity++;
375 			else if (sr & SR_FE)
376 				port->icount.frame++;
377 			else if (sr & SR_OVR) {
378 				port->icount.overrun++;
379 				sccnxp_port_write(port, SCCNXP_CR_REG,
380 						  CR_CMD_STATUS_RESET);
381 			}
382 
383 			sr &= port->read_status_mask;
384 			if (sr & SR_BRK)
385 				flag = TTY_BREAK;
386 			else if (sr & SR_PE)
387 				flag = TTY_PARITY;
388 			else if (sr & SR_FE)
389 				flag = TTY_FRAME;
390 			else if (sr & SR_OVR)
391 				flag = TTY_OVERRUN;
392 		}
393 
394 		if (uart_handle_sysrq_char(port, ch))
395 			continue;
396 
397 		if (sr & port->ignore_status_mask)
398 			continue;
399 
400 		uart_insert_char(port, sr, SR_OVR, ch, flag);
401 	}
402 
403 	tty_flip_buffer_push(&port->state->port);
404 }
405 
406 static void sccnxp_handle_tx(struct uart_port *port)
407 {
408 	u8 sr;
409 	struct circ_buf *xmit = &port->state->xmit;
410 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
411 
412 	if (unlikely(port->x_char)) {
413 		sccnxp_port_write(port, SCCNXP_THR_REG, port->x_char);
414 		port->icount.tx++;
415 		port->x_char = 0;
416 		return;
417 	}
418 
419 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
420 		/* Disable TX if FIFO is empty */
421 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXEMT) {
422 			sccnxp_disable_irq(port, IMR_TXRDY);
423 
424 			/* Set direction to input */
425 			if (s->chip->flags & SCCNXP_HAVE_IO)
426 				sccnxp_set_bit(port, DIR_OP, 0);
427 		}
428 		return;
429 	}
430 
431 	while (!uart_circ_empty(xmit)) {
432 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
433 		if (!(sr & SR_TXRDY))
434 			break;
435 
436 		sccnxp_port_write(port, SCCNXP_THR_REG, xmit->buf[xmit->tail]);
437 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
438 		port->icount.tx++;
439 	}
440 
441 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
442 		uart_write_wakeup(port);
443 }
444 
445 static void sccnxp_handle_events(struct sccnxp_port *s)
446 {
447 	int i;
448 	u8 isr;
449 
450 	do {
451 		isr = sccnxp_read(&s->port[0], SCCNXP_ISR_REG);
452 		isr &= s->imr;
453 		if (!isr)
454 			break;
455 
456 		for (i = 0; i < s->uart.nr; i++) {
457 			if (s->opened[i] && (isr & ISR_RXRDY(i)))
458 				sccnxp_handle_rx(&s->port[i]);
459 			if (s->opened[i] && (isr & ISR_TXRDY(i)))
460 				sccnxp_handle_tx(&s->port[i]);
461 		}
462 	} while (1);
463 }
464 
465 static void sccnxp_timer(struct timer_list *t)
466 {
467 	struct sccnxp_port *s = from_timer(s, t, timer);
468 	unsigned long flags;
469 
470 	spin_lock_irqsave(&s->lock, flags);
471 	sccnxp_handle_events(s);
472 	spin_unlock_irqrestore(&s->lock, flags);
473 
474 	mod_timer(&s->timer, jiffies + usecs_to_jiffies(s->pdata.poll_time_us));
475 }
476 
477 static irqreturn_t sccnxp_ist(int irq, void *dev_id)
478 {
479 	struct sccnxp_port *s = (struct sccnxp_port *)dev_id;
480 	unsigned long flags;
481 
482 	spin_lock_irqsave(&s->lock, flags);
483 	sccnxp_handle_events(s);
484 	spin_unlock_irqrestore(&s->lock, flags);
485 
486 	return IRQ_HANDLED;
487 }
488 
489 static void sccnxp_start_tx(struct uart_port *port)
490 {
491 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
492 	unsigned long flags;
493 
494 	spin_lock_irqsave(&s->lock, flags);
495 
496 	/* Set direction to output */
497 	if (s->chip->flags & SCCNXP_HAVE_IO)
498 		sccnxp_set_bit(port, DIR_OP, 1);
499 
500 	sccnxp_enable_irq(port, IMR_TXRDY);
501 
502 	spin_unlock_irqrestore(&s->lock, flags);
503 }
504 
505 static void sccnxp_stop_tx(struct uart_port *port)
506 {
507 	/* Do nothing */
508 }
509 
510 static void sccnxp_stop_rx(struct uart_port *port)
511 {
512 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
513 	unsigned long flags;
514 
515 	spin_lock_irqsave(&s->lock, flags);
516 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE);
517 	spin_unlock_irqrestore(&s->lock, flags);
518 }
519 
520 static unsigned int sccnxp_tx_empty(struct uart_port *port)
521 {
522 	u8 val;
523 	unsigned long flags;
524 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
525 
526 	spin_lock_irqsave(&s->lock, flags);
527 	val = sccnxp_port_read(port, SCCNXP_SR_REG);
528 	spin_unlock_irqrestore(&s->lock, flags);
529 
530 	return (val & SR_TXEMT) ? TIOCSER_TEMT : 0;
531 }
532 
533 static void sccnxp_set_mctrl(struct uart_port *port, unsigned int mctrl)
534 {
535 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
536 	unsigned long flags;
537 
538 	if (!(s->chip->flags & SCCNXP_HAVE_IO))
539 		return;
540 
541 	spin_lock_irqsave(&s->lock, flags);
542 
543 	sccnxp_set_bit(port, DTR_OP, mctrl & TIOCM_DTR);
544 	sccnxp_set_bit(port, RTS_OP, mctrl & TIOCM_RTS);
545 
546 	spin_unlock_irqrestore(&s->lock, flags);
547 }
548 
549 static unsigned int sccnxp_get_mctrl(struct uart_port *port)
550 {
551 	u8 bitmask, ipr;
552 	unsigned long flags;
553 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
554 	unsigned int mctrl = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
555 
556 	if (!(s->chip->flags & SCCNXP_HAVE_IO))
557 		return mctrl;
558 
559 	spin_lock_irqsave(&s->lock, flags);
560 
561 	ipr = ~sccnxp_read(port, SCCNXP_IPCR_REG);
562 
563 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DSR_IP)) {
564 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
565 					  DSR_IP);
566 		mctrl &= ~TIOCM_DSR;
567 		mctrl |= (ipr & bitmask) ? TIOCM_DSR : 0;
568 	}
569 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(CTS_IP)) {
570 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
571 					  CTS_IP);
572 		mctrl &= ~TIOCM_CTS;
573 		mctrl |= (ipr & bitmask) ? TIOCM_CTS : 0;
574 	}
575 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DCD_IP)) {
576 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
577 					  DCD_IP);
578 		mctrl &= ~TIOCM_CAR;
579 		mctrl |= (ipr & bitmask) ? TIOCM_CAR : 0;
580 	}
581 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(RNG_IP)) {
582 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
583 					  RNG_IP);
584 		mctrl &= ~TIOCM_RNG;
585 		mctrl |= (ipr & bitmask) ? TIOCM_RNG : 0;
586 	}
587 
588 	spin_unlock_irqrestore(&s->lock, flags);
589 
590 	return mctrl;
591 }
592 
593 static void sccnxp_break_ctl(struct uart_port *port, int break_state)
594 {
595 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
596 	unsigned long flags;
597 
598 	spin_lock_irqsave(&s->lock, flags);
599 	sccnxp_port_write(port, SCCNXP_CR_REG, break_state ?
600 			  CR_CMD_START_BREAK : CR_CMD_STOP_BREAK);
601 	spin_unlock_irqrestore(&s->lock, flags);
602 }
603 
604 static void sccnxp_set_termios(struct uart_port *port,
605 			       struct ktermios *termios, struct ktermios *old)
606 {
607 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
608 	unsigned long flags;
609 	u8 mr1, mr2;
610 	int baud;
611 
612 	spin_lock_irqsave(&s->lock, flags);
613 
614 	/* Mask termios capabilities we don't support */
615 	termios->c_cflag &= ~CMSPAR;
616 
617 	/* Disable RX & TX, reset break condition, status and FIFOs */
618 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET |
619 					       CR_RX_DISABLE | CR_TX_DISABLE);
620 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
621 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
622 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
623 
624 	/* Word size */
625 	switch (termios->c_cflag & CSIZE) {
626 	case CS5:
627 		mr1 = MR1_BITS_5;
628 		break;
629 	case CS6:
630 		mr1 = MR1_BITS_6;
631 		break;
632 	case CS7:
633 		mr1 = MR1_BITS_7;
634 		break;
635 	case CS8:
636 	default:
637 		mr1 = MR1_BITS_8;
638 		break;
639 	}
640 
641 	/* Parity */
642 	if (termios->c_cflag & PARENB) {
643 		if (termios->c_cflag & PARODD)
644 			mr1 |= MR1_PAR_ODD;
645 	} else
646 		mr1 |= MR1_PAR_NO;
647 
648 	/* Stop bits */
649 	mr2 = (termios->c_cflag & CSTOPB) ? MR2_STOP2 : MR2_STOP1;
650 
651 	/* Update desired format */
652 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR1);
653 	sccnxp_port_write(port, SCCNXP_MR_REG, mr1);
654 	sccnxp_port_write(port, SCCNXP_MR_REG, mr2);
655 
656 	/* Set read status mask */
657 	port->read_status_mask = SR_OVR;
658 	if (termios->c_iflag & INPCK)
659 		port->read_status_mask |= SR_PE | SR_FE;
660 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
661 		port->read_status_mask |= SR_BRK;
662 
663 	/* Set status ignore mask */
664 	port->ignore_status_mask = 0;
665 	if (termios->c_iflag & IGNBRK)
666 		port->ignore_status_mask |= SR_BRK;
667 	if (termios->c_iflag & IGNPAR)
668 		port->ignore_status_mask |= SR_PE;
669 	if (!(termios->c_cflag & CREAD))
670 		port->ignore_status_mask |= SR_PE | SR_OVR | SR_FE | SR_BRK;
671 
672 	/* Setup baudrate */
673 	baud = uart_get_baud_rate(port, termios, old, 50,
674 				  (s->chip->flags & SCCNXP_HAVE_MR0) ?
675 				  230400 : 38400);
676 	baud = sccnxp_set_baud(port, baud);
677 
678 	/* Update timeout according to new baud rate */
679 	uart_update_timeout(port, termios->c_cflag, baud);
680 
681 	/* Report actual baudrate back to core */
682 	if (tty_termios_baud_rate(termios))
683 		tty_termios_encode_baud_rate(termios, baud, baud);
684 
685 	/* Enable RX & TX */
686 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
687 
688 	spin_unlock_irqrestore(&s->lock, flags);
689 }
690 
691 static int sccnxp_startup(struct uart_port *port)
692 {
693 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
694 	unsigned long flags;
695 
696 	spin_lock_irqsave(&s->lock, flags);
697 
698 	if (s->chip->flags & SCCNXP_HAVE_IO) {
699 		/* Outputs are controlled manually */
700 		sccnxp_write(port, SCCNXP_OPCR_REG, 0);
701 	}
702 
703 	/* Reset break condition, status and FIFOs */
704 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET);
705 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
706 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
707 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
708 
709 	/* Enable RX & TX */
710 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
711 
712 	/* Enable RX interrupt */
713 	sccnxp_enable_irq(port, IMR_RXRDY);
714 
715 	s->opened[port->line] = 1;
716 
717 	spin_unlock_irqrestore(&s->lock, flags);
718 
719 	return 0;
720 }
721 
722 static void sccnxp_shutdown(struct uart_port *port)
723 {
724 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
725 	unsigned long flags;
726 
727 	spin_lock_irqsave(&s->lock, flags);
728 
729 	s->opened[port->line] = 0;
730 
731 	/* Disable interrupts */
732 	sccnxp_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
733 
734 	/* Disable TX & RX */
735 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE | CR_TX_DISABLE);
736 
737 	/* Leave direction to input */
738 	if (s->chip->flags & SCCNXP_HAVE_IO)
739 		sccnxp_set_bit(port, DIR_OP, 0);
740 
741 	spin_unlock_irqrestore(&s->lock, flags);
742 }
743 
744 static const char *sccnxp_type(struct uart_port *port)
745 {
746 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
747 
748 	return (port->type == PORT_SC26XX) ? s->chip->name : NULL;
749 }
750 
751 static void sccnxp_release_port(struct uart_port *port)
752 {
753 	/* Do nothing */
754 }
755 
756 static int sccnxp_request_port(struct uart_port *port)
757 {
758 	/* Do nothing */
759 	return 0;
760 }
761 
762 static void sccnxp_config_port(struct uart_port *port, int flags)
763 {
764 	if (flags & UART_CONFIG_TYPE)
765 		port->type = PORT_SC26XX;
766 }
767 
768 static int sccnxp_verify_port(struct uart_port *port, struct serial_struct *s)
769 {
770 	if ((s->type == PORT_UNKNOWN) || (s->type == PORT_SC26XX))
771 		return 0;
772 	if (s->irq == port->irq)
773 		return 0;
774 
775 	return -EINVAL;
776 }
777 
778 static const struct uart_ops sccnxp_ops = {
779 	.tx_empty	= sccnxp_tx_empty,
780 	.set_mctrl	= sccnxp_set_mctrl,
781 	.get_mctrl	= sccnxp_get_mctrl,
782 	.stop_tx	= sccnxp_stop_tx,
783 	.start_tx	= sccnxp_start_tx,
784 	.stop_rx	= sccnxp_stop_rx,
785 	.break_ctl	= sccnxp_break_ctl,
786 	.startup	= sccnxp_startup,
787 	.shutdown	= sccnxp_shutdown,
788 	.set_termios	= sccnxp_set_termios,
789 	.type		= sccnxp_type,
790 	.release_port	= sccnxp_release_port,
791 	.request_port	= sccnxp_request_port,
792 	.config_port	= sccnxp_config_port,
793 	.verify_port	= sccnxp_verify_port,
794 };
795 
796 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
797 static void sccnxp_console_putchar(struct uart_port *port, int c)
798 {
799 	int tryes = 100000;
800 
801 	while (tryes--) {
802 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXRDY) {
803 			sccnxp_port_write(port, SCCNXP_THR_REG, c);
804 			break;
805 		}
806 		barrier();
807 	}
808 }
809 
810 static void sccnxp_console_write(struct console *co, const char *c, unsigned n)
811 {
812 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
813 	struct uart_port *port = &s->port[co->index];
814 	unsigned long flags;
815 
816 	spin_lock_irqsave(&s->lock, flags);
817 	uart_console_write(port, c, n, sccnxp_console_putchar);
818 	spin_unlock_irqrestore(&s->lock, flags);
819 }
820 
821 static int sccnxp_console_setup(struct console *co, char *options)
822 {
823 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
824 	struct uart_port *port = &s->port[(co->index > 0) ? co->index : 0];
825 	int baud = 9600, bits = 8, parity = 'n', flow = 'n';
826 
827 	if (options)
828 		uart_parse_options(options, &baud, &parity, &bits, &flow);
829 
830 	return uart_set_options(port, co, baud, parity, bits, flow);
831 }
832 #endif
833 
834 static const struct platform_device_id sccnxp_id_table[] = {
835 	{ .name = "sc2681",	.driver_data = (kernel_ulong_t)&sc2681, },
836 	{ .name = "sc2691",	.driver_data = (kernel_ulong_t)&sc2691, },
837 	{ .name = "sc2692",	.driver_data = (kernel_ulong_t)&sc2692, },
838 	{ .name = "sc2891",	.driver_data = (kernel_ulong_t)&sc2891, },
839 	{ .name = "sc2892",	.driver_data = (kernel_ulong_t)&sc2892, },
840 	{ .name = "sc28202",	.driver_data = (kernel_ulong_t)&sc28202, },
841 	{ .name = "sc68681",	.driver_data = (kernel_ulong_t)&sc68681, },
842 	{ .name = "sc68692",	.driver_data = (kernel_ulong_t)&sc68692, },
843 	{ }
844 };
845 MODULE_DEVICE_TABLE(platform, sccnxp_id_table);
846 
847 static int sccnxp_probe(struct platform_device *pdev)
848 {
849 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
850 	struct sccnxp_pdata *pdata = dev_get_platdata(&pdev->dev);
851 	int i, ret, uartclk;
852 	struct sccnxp_port *s;
853 	void __iomem *membase;
854 	struct clk *clk;
855 
856 	membase = devm_ioremap_resource(&pdev->dev, res);
857 	if (IS_ERR(membase))
858 		return PTR_ERR(membase);
859 
860 	s = devm_kzalloc(&pdev->dev, sizeof(struct sccnxp_port), GFP_KERNEL);
861 	if (!s) {
862 		dev_err(&pdev->dev, "Error allocating port structure\n");
863 		return -ENOMEM;
864 	}
865 	platform_set_drvdata(pdev, s);
866 
867 	spin_lock_init(&s->lock);
868 
869 	s->chip = (struct sccnxp_chip *)pdev->id_entry->driver_data;
870 
871 	s->regulator = devm_regulator_get(&pdev->dev, "vcc");
872 	if (!IS_ERR(s->regulator)) {
873 		ret = regulator_enable(s->regulator);
874 		if (ret) {
875 			dev_err(&pdev->dev,
876 				"Failed to enable regulator: %i\n", ret);
877 			return ret;
878 		}
879 	} else if (PTR_ERR(s->regulator) == -EPROBE_DEFER)
880 		return -EPROBE_DEFER;
881 
882 	clk = devm_clk_get(&pdev->dev, NULL);
883 	if (IS_ERR(clk)) {
884 		ret = PTR_ERR(clk);
885 		if (ret == -EPROBE_DEFER)
886 			goto err_out;
887 		uartclk = 0;
888 	} else {
889 		ret = clk_prepare_enable(clk);
890 		if (ret)
891 			goto err_out;
892 
893 		ret = devm_add_action_or_reset(&pdev->dev,
894 				(void(*)(void *))clk_disable_unprepare,
895 				clk);
896 		if (ret)
897 			goto err_out;
898 
899 		uartclk = clk_get_rate(clk);
900 	}
901 
902 	if (!uartclk) {
903 		dev_notice(&pdev->dev, "Using default clock frequency\n");
904 		uartclk = s->chip->freq_std;
905 	}
906 
907 	/* Check input frequency */
908 	if ((uartclk < s->chip->freq_min) || (uartclk > s->chip->freq_max)) {
909 		dev_err(&pdev->dev, "Frequency out of bounds\n");
910 		ret = -EINVAL;
911 		goto err_out;
912 	}
913 
914 	if (pdata)
915 		memcpy(&s->pdata, pdata, sizeof(struct sccnxp_pdata));
916 
917 	if (s->pdata.poll_time_us) {
918 		dev_info(&pdev->dev, "Using poll mode, resolution %u usecs\n",
919 			 s->pdata.poll_time_us);
920 		s->poll = 1;
921 	}
922 
923 	if (!s->poll) {
924 		s->irq = platform_get_irq(pdev, 0);
925 		if (s->irq < 0) {
926 			dev_err(&pdev->dev, "Missing irq resource data\n");
927 			ret = -ENXIO;
928 			goto err_out;
929 		}
930 	}
931 
932 	s->uart.owner		= THIS_MODULE;
933 	s->uart.dev_name	= "ttySC";
934 	s->uart.major		= SCCNXP_MAJOR;
935 	s->uart.minor		= SCCNXP_MINOR;
936 	s->uart.nr		= s->chip->nr;
937 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
938 	s->uart.cons		= &s->console;
939 	s->uart.cons->device	= uart_console_device;
940 	s->uart.cons->write	= sccnxp_console_write;
941 	s->uart.cons->setup	= sccnxp_console_setup;
942 	s->uart.cons->flags	= CON_PRINTBUFFER;
943 	s->uart.cons->index	= -1;
944 	s->uart.cons->data	= s;
945 	strcpy(s->uart.cons->name, "ttySC");
946 #endif
947 	ret = uart_register_driver(&s->uart);
948 	if (ret) {
949 		dev_err(&pdev->dev, "Registering UART driver failed\n");
950 		goto err_out;
951 	}
952 
953 	for (i = 0; i < s->uart.nr; i++) {
954 		s->port[i].line		= i;
955 		s->port[i].dev		= &pdev->dev;
956 		s->port[i].irq		= s->irq;
957 		s->port[i].type		= PORT_SC26XX;
958 		s->port[i].fifosize	= s->chip->fifosize;
959 		s->port[i].flags	= UPF_SKIP_TEST | UPF_FIXED_TYPE;
960 		s->port[i].iotype	= UPIO_MEM;
961 		s->port[i].mapbase	= res->start;
962 		s->port[i].membase	= membase;
963 		s->port[i].regshift	= s->pdata.reg_shift;
964 		s->port[i].uartclk	= uartclk;
965 		s->port[i].ops		= &sccnxp_ops;
966 		uart_add_one_port(&s->uart, &s->port[i]);
967 		/* Set direction to input */
968 		if (s->chip->flags & SCCNXP_HAVE_IO)
969 			sccnxp_set_bit(&s->port[i], DIR_OP, 0);
970 	}
971 
972 	/* Disable interrupts */
973 	s->imr = 0;
974 	sccnxp_write(&s->port[0], SCCNXP_IMR_REG, 0);
975 
976 	if (!s->poll) {
977 		ret = devm_request_threaded_irq(&pdev->dev, s->irq, NULL,
978 						sccnxp_ist,
979 						IRQF_TRIGGER_FALLING |
980 						IRQF_ONESHOT,
981 						dev_name(&pdev->dev), s);
982 		if (!ret)
983 			return 0;
984 
985 		dev_err(&pdev->dev, "Unable to reguest IRQ %i\n", s->irq);
986 	} else {
987 		timer_setup(&s->timer, sccnxp_timer, 0);
988 		mod_timer(&s->timer, jiffies +
989 			  usecs_to_jiffies(s->pdata.poll_time_us));
990 		return 0;
991 	}
992 
993 	uart_unregister_driver(&s->uart);
994 err_out:
995 	if (!IS_ERR(s->regulator))
996 		regulator_disable(s->regulator);
997 
998 	return ret;
999 }
1000 
1001 static int sccnxp_remove(struct platform_device *pdev)
1002 {
1003 	int i;
1004 	struct sccnxp_port *s = platform_get_drvdata(pdev);
1005 
1006 	if (!s->poll)
1007 		devm_free_irq(&pdev->dev, s->irq, s);
1008 	else
1009 		del_timer_sync(&s->timer);
1010 
1011 	for (i = 0; i < s->uart.nr; i++)
1012 		uart_remove_one_port(&s->uart, &s->port[i]);
1013 
1014 	uart_unregister_driver(&s->uart);
1015 
1016 	if (!IS_ERR(s->regulator))
1017 		return regulator_disable(s->regulator);
1018 
1019 	return 0;
1020 }
1021 
1022 static struct platform_driver sccnxp_uart_driver = {
1023 	.driver = {
1024 		.name	= SCCNXP_NAME,
1025 	},
1026 	.probe		= sccnxp_probe,
1027 	.remove		= sccnxp_remove,
1028 	.id_table	= sccnxp_id_table,
1029 };
1030 module_platform_driver(sccnxp_uart_driver);
1031 
1032 MODULE_LICENSE("GPL v2");
1033 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1034 MODULE_DESCRIPTION("SCCNXP serial driver");
1035