xref: /openbmc/linux/drivers/tty/serial/sccnxp.c (revision eb612fa0)
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/err.h>
19 #include <linux/module.h>
20 #include <linux/device.h>
21 #include <linux/console.h>
22 #include <linux/serial_core.h>
23 #include <linux/serial.h>
24 #include <linux/io.h>
25 #include <linux/tty.h>
26 #include <linux/tty_flip.h>
27 #include <linux/platform_device.h>
28 #include <linux/platform_data/sccnxp.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 /* Supported chip types */
96 enum {
97 	SCCNXP_TYPE_SC2681	= 2681,
98 	SCCNXP_TYPE_SC2691	= 2691,
99 	SCCNXP_TYPE_SC2692	= 2692,
100 	SCCNXP_TYPE_SC2891	= 2891,
101 	SCCNXP_TYPE_SC2892	= 2892,
102 	SCCNXP_TYPE_SC28202	= 28202,
103 	SCCNXP_TYPE_SC68681	= 68681,
104 	SCCNXP_TYPE_SC68692	= 68692,
105 };
106 
107 struct sccnxp_port {
108 	struct uart_driver	uart;
109 	struct uart_port	port[SCCNXP_MAX_UARTS];
110 
111 	const char		*name;
112 	int			irq;
113 
114 	u8			imr;
115 	u8			addr_mask;
116 	int			freq_std;
117 
118 	int			flags;
119 #define SCCNXP_HAVE_IO		0x00000001
120 #define SCCNXP_HAVE_MR0		0x00000002
121 
122 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
123 	struct console		console;
124 #endif
125 
126 	struct mutex		sccnxp_mutex;
127 
128 	struct sccnxp_pdata	pdata;
129 };
130 
131 static inline u8 sccnxp_raw_read(void __iomem *base, u8 reg, u8 shift)
132 {
133 	return readb(base + (reg << shift));
134 }
135 
136 static inline void sccnxp_raw_write(void __iomem *base, u8 reg, u8 shift, u8 v)
137 {
138 	writeb(v, base + (reg << shift));
139 }
140 
141 static inline u8 sccnxp_read(struct uart_port *port, u8 reg)
142 {
143 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
144 
145 	return sccnxp_raw_read(port->membase, reg & s->addr_mask,
146 			       port->regshift);
147 }
148 
149 static inline void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
150 {
151 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
152 
153 	sccnxp_raw_write(port->membase, reg & s->addr_mask, port->regshift, v);
154 }
155 
156 static inline u8 sccnxp_port_read(struct uart_port *port, u8 reg)
157 {
158 	return sccnxp_read(port, (port->line << 3) + reg);
159 }
160 
161 static inline void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
162 {
163 	sccnxp_write(port, (port->line << 3) + reg, v);
164 }
165 
166 static int sccnxp_update_best_err(int a, int b, int *besterr)
167 {
168 	int err = abs(a - b);
169 
170 	if ((*besterr < 0) || (*besterr > err)) {
171 		*besterr = err;
172 		return 0;
173 	}
174 
175 	return 1;
176 }
177 
178 struct baud_table {
179 	u8	csr;
180 	u8	acr;
181 	u8	mr0;
182 	int	baud;
183 };
184 
185 const struct baud_table baud_std[] = {
186 	{ 0,	ACR_BAUD0,	MR0_BAUD_NORMAL,	50, },
187 	{ 0,	ACR_BAUD1,	MR0_BAUD_NORMAL,	75, },
188 	{ 1,	ACR_BAUD0,	MR0_BAUD_NORMAL,	110, },
189 	{ 2,	ACR_BAUD0,	MR0_BAUD_NORMAL,	134, },
190 	{ 3,	ACR_BAUD1,	MR0_BAUD_NORMAL,	150, },
191 	{ 3,	ACR_BAUD0,	MR0_BAUD_NORMAL,	200, },
192 	{ 4,	ACR_BAUD0,	MR0_BAUD_NORMAL,	300, },
193 	{ 0,	ACR_BAUD1,	MR0_BAUD_EXT1,		450, },
194 	{ 1,	ACR_BAUD0,	MR0_BAUD_EXT2,		880, },
195 	{ 3,	ACR_BAUD1,	MR0_BAUD_EXT1,		900, },
196 	{ 5,	ACR_BAUD0,	MR0_BAUD_NORMAL,	600, },
197 	{ 7,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1050, },
198 	{ 2,	ACR_BAUD0,	MR0_BAUD_EXT2,		1076, },
199 	{ 6,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1200, },
200 	{ 10,	ACR_BAUD1,	MR0_BAUD_NORMAL,	1800, },
201 	{ 7,	ACR_BAUD1,	MR0_BAUD_NORMAL,	2000, },
202 	{ 8,	ACR_BAUD0,	MR0_BAUD_NORMAL,	2400, },
203 	{ 5,	ACR_BAUD1,	MR0_BAUD_EXT1,		3600, },
204 	{ 9,	ACR_BAUD0,	MR0_BAUD_NORMAL,	4800, },
205 	{ 10,	ACR_BAUD0,	MR0_BAUD_NORMAL,	7200, },
206 	{ 11,	ACR_BAUD0,	MR0_BAUD_NORMAL,	9600, },
207 	{ 8,	ACR_BAUD0,	MR0_BAUD_EXT1,		14400, },
208 	{ 12,	ACR_BAUD1,	MR0_BAUD_NORMAL,	19200, },
209 	{ 9,	ACR_BAUD0,	MR0_BAUD_EXT1,		28800, },
210 	{ 12,	ACR_BAUD0,	MR0_BAUD_NORMAL,	38400, },
211 	{ 11,	ACR_BAUD0,	MR0_BAUD_EXT1,		57600, },
212 	{ 12,	ACR_BAUD1,	MR0_BAUD_EXT1,		115200, },
213 	{ 12,	ACR_BAUD0,	MR0_BAUD_EXT1,		230400, },
214 	{ 0, 0, 0, 0 }
215 };
216 
217 static int sccnxp_set_baud(struct uart_port *port, int baud)
218 {
219 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
220 	int div_std, tmp_baud, bestbaud = baud, besterr = -1;
221 	u8 i, acr = 0, csr = 0, mr0 = 0;
222 
223 	/* Find best baud from table */
224 	for (i = 0; baud_std[i].baud && besterr; i++) {
225 		if (baud_std[i].mr0 && !(s->flags & SCCNXP_HAVE_MR0))
226 			continue;
227 		div_std = DIV_ROUND_CLOSEST(s->freq_std, baud_std[i].baud);
228 		tmp_baud = DIV_ROUND_CLOSEST(port->uartclk, div_std);
229 		if (!sccnxp_update_best_err(baud, tmp_baud, &besterr)) {
230 			acr = baud_std[i].acr;
231 			csr = baud_std[i].csr;
232 			mr0 = baud_std[i].mr0;
233 			bestbaud = tmp_baud;
234 		}
235 	}
236 
237 	if (s->flags & SCCNXP_HAVE_MR0) {
238 		/* Enable FIFO, set half level for TX */
239 		mr0 |= MR0_FIFO | MR0_TXLVL;
240 		/* Update MR0 */
241 		sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR0);
242 		sccnxp_port_write(port, SCCNXP_MR_REG, mr0);
243 	}
244 
245 	sccnxp_port_write(port, SCCNXP_ACR_REG, acr | ACR_TIMER_MODE);
246 	sccnxp_port_write(port, SCCNXP_CSR_REG, (csr << 4) | csr);
247 
248 	if (baud != bestbaud)
249 		dev_dbg(port->dev, "Baudrate desired: %i, calculated: %i\n",
250 			baud, bestbaud);
251 
252 	return bestbaud;
253 }
254 
255 static void sccnxp_enable_irq(struct uart_port *port, int mask)
256 {
257 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
258 
259 	s->imr |= mask << (port->line * 4);
260 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
261 }
262 
263 static void sccnxp_disable_irq(struct uart_port *port, int mask)
264 {
265 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
266 
267 	s->imr &= ~(mask << (port->line * 4));
268 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
269 }
270 
271 static void sccnxp_set_bit(struct uart_port *port, int sig, int state)
272 {
273 	u8 bitmask;
274 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
275 
276 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(sig)) {
277 		bitmask = 1 << MCTRL_OBIT(s->pdata.mctrl_cfg[port->line], sig);
278 		if (state)
279 			sccnxp_write(port, SCCNXP_SOP_REG, bitmask);
280 		else
281 			sccnxp_write(port, SCCNXP_ROP_REG, bitmask);
282 	}
283 }
284 
285 static void sccnxp_handle_rx(struct uart_port *port)
286 {
287 	u8 sr;
288 	unsigned int ch, flag;
289 	struct tty_struct *tty = tty_port_tty_get(&port->state->port);
290 
291 	if (!tty)
292 		return;
293 
294 	for (;;) {
295 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
296 		if (!(sr & SR_RXRDY))
297 			break;
298 		sr &= SR_PE | SR_FE | SR_OVR | SR_BRK;
299 
300 		ch = sccnxp_port_read(port, SCCNXP_RHR_REG);
301 
302 		port->icount.rx++;
303 		flag = TTY_NORMAL;
304 
305 		if (unlikely(sr)) {
306 			if (sr & SR_BRK) {
307 				port->icount.brk++;
308 				if (uart_handle_break(port))
309 					continue;
310 			} else if (sr & SR_PE)
311 				port->icount.parity++;
312 			else if (sr & SR_FE)
313 				port->icount.frame++;
314 			else if (sr & SR_OVR)
315 				port->icount.overrun++;
316 
317 			sr &= port->read_status_mask;
318 			if (sr & SR_BRK)
319 				flag = TTY_BREAK;
320 			else if (sr & SR_PE)
321 				flag = TTY_PARITY;
322 			else if (sr & SR_FE)
323 				flag = TTY_FRAME;
324 			else if (sr & SR_OVR)
325 				flag = TTY_OVERRUN;
326 		}
327 
328 		if (uart_handle_sysrq_char(port, ch))
329 			continue;
330 
331 		if (sr & port->ignore_status_mask)
332 			continue;
333 
334 		uart_insert_char(port, sr, SR_OVR, ch, flag);
335 	}
336 
337 	tty_flip_buffer_push(tty);
338 
339 	tty_kref_put(tty);
340 }
341 
342 static void sccnxp_handle_tx(struct uart_port *port)
343 {
344 	u8 sr;
345 	struct circ_buf *xmit = &port->state->xmit;
346 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
347 
348 	if (unlikely(port->x_char)) {
349 		sccnxp_port_write(port, SCCNXP_THR_REG, port->x_char);
350 		port->icount.tx++;
351 		port->x_char = 0;
352 		return;
353 	}
354 
355 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
356 		/* Disable TX if FIFO is empty */
357 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXEMT) {
358 			sccnxp_disable_irq(port, IMR_TXRDY);
359 
360 			/* Set direction to input */
361 			if (s->flags & SCCNXP_HAVE_IO)
362 				sccnxp_set_bit(port, DIR_OP, 0);
363 		}
364 		return;
365 	}
366 
367 	while (!uart_circ_empty(xmit)) {
368 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
369 		if (!(sr & SR_TXRDY))
370 			break;
371 
372 		sccnxp_port_write(port, SCCNXP_THR_REG, xmit->buf[xmit->tail]);
373 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
374 		port->icount.tx++;
375 	}
376 
377 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
378 		uart_write_wakeup(port);
379 }
380 
381 static irqreturn_t sccnxp_ist(int irq, void *dev_id)
382 {
383 	int i;
384 	u8 isr;
385 	struct sccnxp_port *s = (struct sccnxp_port *)dev_id;
386 
387 	mutex_lock(&s->sccnxp_mutex);
388 
389 	for (;;) {
390 		isr = sccnxp_read(&s->port[0], SCCNXP_ISR_REG);
391 		isr &= s->imr;
392 		if (!isr)
393 			break;
394 
395 		dev_dbg(s->port[0].dev, "IRQ status: 0x%02x\n", isr);
396 
397 		for (i = 0; i < s->uart.nr; i++) {
398 			if (isr & ISR_RXRDY(i))
399 				sccnxp_handle_rx(&s->port[i]);
400 			if (isr & ISR_TXRDY(i))
401 				sccnxp_handle_tx(&s->port[i]);
402 		}
403 	}
404 
405 	mutex_unlock(&s->sccnxp_mutex);
406 
407 	return IRQ_HANDLED;
408 }
409 
410 static void sccnxp_start_tx(struct uart_port *port)
411 {
412 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
413 
414 	mutex_lock(&s->sccnxp_mutex);
415 
416 	/* Set direction to output */
417 	if (s->flags & SCCNXP_HAVE_IO)
418 		sccnxp_set_bit(port, DIR_OP, 1);
419 
420 	sccnxp_enable_irq(port, IMR_TXRDY);
421 
422 	mutex_unlock(&s->sccnxp_mutex);
423 }
424 
425 static void sccnxp_stop_tx(struct uart_port *port)
426 {
427 	/* Do nothing */
428 }
429 
430 static void sccnxp_stop_rx(struct uart_port *port)
431 {
432 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
433 
434 	mutex_lock(&s->sccnxp_mutex);
435 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE);
436 	mutex_unlock(&s->sccnxp_mutex);
437 }
438 
439 static unsigned int sccnxp_tx_empty(struct uart_port *port)
440 {
441 	u8 val;
442 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
443 
444 	mutex_lock(&s->sccnxp_mutex);
445 	val = sccnxp_port_read(port, SCCNXP_SR_REG);
446 	mutex_unlock(&s->sccnxp_mutex);
447 
448 	return (val & SR_TXEMT) ? TIOCSER_TEMT : 0;
449 }
450 
451 static void sccnxp_enable_ms(struct uart_port *port)
452 {
453 	/* Do nothing */
454 }
455 
456 static void sccnxp_set_mctrl(struct uart_port *port, unsigned int mctrl)
457 {
458 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
459 
460 	if (!(s->flags & SCCNXP_HAVE_IO))
461 		return;
462 
463 	mutex_lock(&s->sccnxp_mutex);
464 
465 	sccnxp_set_bit(port, DTR_OP, mctrl & TIOCM_DTR);
466 	sccnxp_set_bit(port, RTS_OP, mctrl & TIOCM_RTS);
467 
468 	mutex_unlock(&s->sccnxp_mutex);
469 }
470 
471 static unsigned int sccnxp_get_mctrl(struct uart_port *port)
472 {
473 	u8 bitmask, ipr;
474 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
475 	unsigned int mctrl = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
476 
477 	if (!(s->flags & SCCNXP_HAVE_IO))
478 		return mctrl;
479 
480 	mutex_lock(&s->sccnxp_mutex);
481 
482 	ipr = ~sccnxp_read(port, SCCNXP_IPCR_REG);
483 
484 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DSR_IP)) {
485 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
486 					  DSR_IP);
487 		mctrl &= ~TIOCM_DSR;
488 		mctrl |= (ipr & bitmask) ? TIOCM_DSR : 0;
489 	}
490 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(CTS_IP)) {
491 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
492 					  CTS_IP);
493 		mctrl &= ~TIOCM_CTS;
494 		mctrl |= (ipr & bitmask) ? TIOCM_CTS : 0;
495 	}
496 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DCD_IP)) {
497 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
498 					  DCD_IP);
499 		mctrl &= ~TIOCM_CAR;
500 		mctrl |= (ipr & bitmask) ? TIOCM_CAR : 0;
501 	}
502 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(RNG_IP)) {
503 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
504 					  RNG_IP);
505 		mctrl &= ~TIOCM_RNG;
506 		mctrl |= (ipr & bitmask) ? TIOCM_RNG : 0;
507 	}
508 
509 	mutex_unlock(&s->sccnxp_mutex);
510 
511 	return mctrl;
512 }
513 
514 static void sccnxp_break_ctl(struct uart_port *port, int break_state)
515 {
516 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
517 
518 	mutex_lock(&s->sccnxp_mutex);
519 	sccnxp_port_write(port, SCCNXP_CR_REG, break_state ?
520 			  CR_CMD_START_BREAK : CR_CMD_STOP_BREAK);
521 	mutex_unlock(&s->sccnxp_mutex);
522 }
523 
524 static void sccnxp_set_termios(struct uart_port *port,
525 			       struct ktermios *termios, struct ktermios *old)
526 {
527 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
528 	u8 mr1, mr2;
529 	int baud;
530 
531 	mutex_lock(&s->sccnxp_mutex);
532 
533 	/* Mask termios capabilities we don't support */
534 	termios->c_cflag &= ~CMSPAR;
535 
536 	/* Disable RX & TX, reset break condition, status and FIFOs */
537 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET |
538 					       CR_RX_DISABLE | CR_TX_DISABLE);
539 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
540 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
541 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
542 
543 	/* Word size */
544 	switch (termios->c_cflag & CSIZE) {
545 	case CS5:
546 		mr1 = MR1_BITS_5;
547 		break;
548 	case CS6:
549 		mr1 = MR1_BITS_6;
550 		break;
551 	case CS7:
552 		mr1 = MR1_BITS_7;
553 		break;
554 	case CS8:
555 	default:
556 		mr1 = MR1_BITS_8;
557 		break;
558 	}
559 
560 	/* Parity */
561 	if (termios->c_cflag & PARENB) {
562 		if (termios->c_cflag & PARODD)
563 			mr1 |= MR1_PAR_ODD;
564 	} else
565 		mr1 |= MR1_PAR_NO;
566 
567 	/* Stop bits */
568 	mr2 = (termios->c_cflag & CSTOPB) ? MR2_STOP2 : MR2_STOP1;
569 
570 	/* Update desired format */
571 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR1);
572 	sccnxp_port_write(port, SCCNXP_MR_REG, mr1);
573 	sccnxp_port_write(port, SCCNXP_MR_REG, mr2);
574 
575 	/* Set read status mask */
576 	port->read_status_mask = SR_OVR;
577 	if (termios->c_iflag & INPCK)
578 		port->read_status_mask |= SR_PE | SR_FE;
579 	if (termios->c_iflag & (BRKINT | PARMRK))
580 		port->read_status_mask |= SR_BRK;
581 
582 	/* Set status ignore mask */
583 	port->ignore_status_mask = 0;
584 	if (termios->c_iflag & IGNBRK)
585 		port->ignore_status_mask |= SR_BRK;
586 	if (!(termios->c_cflag & CREAD))
587 		port->ignore_status_mask |= SR_PE | SR_OVR | SR_FE | SR_BRK;
588 
589 	/* Setup baudrate */
590 	baud = uart_get_baud_rate(port, termios, old, 50,
591 				  (s->flags & SCCNXP_HAVE_MR0) ?
592 				  230400 : 38400);
593 	baud = sccnxp_set_baud(port, baud);
594 
595 	/* Update timeout according to new baud rate */
596 	uart_update_timeout(port, termios->c_cflag, baud);
597 
598 	if (tty_termios_baud_rate(termios))
599 		tty_termios_encode_baud_rate(termios, baud, baud);
600 
601 	/* Enable RX & TX */
602 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
603 
604 	mutex_unlock(&s->sccnxp_mutex);
605 }
606 
607 static int sccnxp_startup(struct uart_port *port)
608 {
609 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
610 
611 	mutex_lock(&s->sccnxp_mutex);
612 
613 	if (s->flags & SCCNXP_HAVE_IO) {
614 		/* Outputs are controlled manually */
615 		sccnxp_write(port, SCCNXP_OPCR_REG, 0);
616 	}
617 
618 	/* Reset break condition, status and FIFOs */
619 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET);
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 	/* Enable RX & TX */
625 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
626 
627 	/* Enable RX interrupt */
628 	sccnxp_enable_irq(port, IMR_RXRDY);
629 
630 	mutex_unlock(&s->sccnxp_mutex);
631 
632 	return 0;
633 }
634 
635 static void sccnxp_shutdown(struct uart_port *port)
636 {
637 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
638 
639 	mutex_lock(&s->sccnxp_mutex);
640 
641 	/* Disable interrupts */
642 	sccnxp_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
643 
644 	/* Disable TX & RX */
645 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE | CR_TX_DISABLE);
646 
647 	/* Leave direction to input */
648 	if (s->flags & SCCNXP_HAVE_IO)
649 		sccnxp_set_bit(port, DIR_OP, 0);
650 
651 	mutex_unlock(&s->sccnxp_mutex);
652 }
653 
654 static const char *sccnxp_type(struct uart_port *port)
655 {
656 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
657 
658 	return (port->type == PORT_SC26XX) ? s->name : NULL;
659 }
660 
661 static void sccnxp_release_port(struct uart_port *port)
662 {
663 	/* Do nothing */
664 }
665 
666 static int sccnxp_request_port(struct uart_port *port)
667 {
668 	/* Do nothing */
669 	return 0;
670 }
671 
672 static void sccnxp_config_port(struct uart_port *port, int flags)
673 {
674 	if (flags & UART_CONFIG_TYPE)
675 		port->type = PORT_SC26XX;
676 }
677 
678 static int sccnxp_verify_port(struct uart_port *port, struct serial_struct *s)
679 {
680 	if ((s->type == PORT_UNKNOWN) || (s->type == PORT_SC26XX))
681 		return 0;
682 	if (s->irq == port->irq)
683 		return 0;
684 
685 	return -EINVAL;
686 }
687 
688 static const struct uart_ops sccnxp_ops = {
689 	.tx_empty	= sccnxp_tx_empty,
690 	.set_mctrl	= sccnxp_set_mctrl,
691 	.get_mctrl	= sccnxp_get_mctrl,
692 	.stop_tx	= sccnxp_stop_tx,
693 	.start_tx	= sccnxp_start_tx,
694 	.stop_rx	= sccnxp_stop_rx,
695 	.enable_ms	= sccnxp_enable_ms,
696 	.break_ctl	= sccnxp_break_ctl,
697 	.startup	= sccnxp_startup,
698 	.shutdown	= sccnxp_shutdown,
699 	.set_termios	= sccnxp_set_termios,
700 	.type		= sccnxp_type,
701 	.release_port	= sccnxp_release_port,
702 	.request_port	= sccnxp_request_port,
703 	.config_port	= sccnxp_config_port,
704 	.verify_port	= sccnxp_verify_port,
705 };
706 
707 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
708 static void sccnxp_console_putchar(struct uart_port *port, int c)
709 {
710 	int tryes = 100000;
711 
712 	while (tryes--) {
713 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXRDY) {
714 			sccnxp_port_write(port, SCCNXP_THR_REG, c);
715 			break;
716 		}
717 		barrier();
718 	}
719 }
720 
721 static void sccnxp_console_write(struct console *co, const char *c, unsigned n)
722 {
723 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
724 	struct uart_port *port = &s->port[co->index];
725 
726 	mutex_lock(&s->sccnxp_mutex);
727 	uart_console_write(port, c, n, sccnxp_console_putchar);
728 	mutex_unlock(&s->sccnxp_mutex);
729 }
730 
731 static int sccnxp_console_setup(struct console *co, char *options)
732 {
733 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
734 	struct uart_port *port = &s->port[(co->index > 0) ? co->index : 0];
735 	int baud = 9600, bits = 8, parity = 'n', flow = 'n';
736 
737 	if (options)
738 		uart_parse_options(options, &baud, &parity, &bits, &flow);
739 
740 	return uart_set_options(port, co, baud, parity, bits, flow);
741 }
742 #endif
743 
744 static int sccnxp_probe(struct platform_device *pdev)
745 {
746 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
747 	int chiptype = pdev->id_entry->driver_data;
748 	struct sccnxp_pdata *pdata = dev_get_platdata(&pdev->dev);
749 	int i, ret, fifosize, freq_min, freq_max;
750 	struct sccnxp_port *s;
751 	void __iomem *membase;
752 
753 	if (!res) {
754 		dev_err(&pdev->dev, "Missing memory resource data\n");
755 		return -EADDRNOTAVAIL;
756 	}
757 
758 	dev_set_name(&pdev->dev, SCCNXP_NAME);
759 
760 	s = devm_kzalloc(&pdev->dev, sizeof(struct sccnxp_port), GFP_KERNEL);
761 	if (!s) {
762 		dev_err(&pdev->dev, "Error allocating port structure\n");
763 		return -ENOMEM;
764 	}
765 	platform_set_drvdata(pdev, s);
766 
767 	mutex_init(&s->sccnxp_mutex);
768 
769 	/* Individual chip settings */
770 	switch (chiptype) {
771 	case SCCNXP_TYPE_SC2681:
772 		s->name		= "SC2681";
773 		s->uart.nr	= 2;
774 		s->freq_std	= 3686400;
775 		s->addr_mask	= 0x0f;
776 		s->flags	= SCCNXP_HAVE_IO;
777 		fifosize	= 3;
778 		freq_min	= 1000000;
779 		freq_max	= 4000000;
780 		break;
781 	case SCCNXP_TYPE_SC2691:
782 		s->name		= "SC2691";
783 		s->uart.nr	= 1;
784 		s->freq_std	= 3686400;
785 		s->addr_mask	= 0x07;
786 		s->flags	= 0;
787 		fifosize	= 3;
788 		freq_min	= 1000000;
789 		freq_max	= 4000000;
790 		break;
791 	case SCCNXP_TYPE_SC2692:
792 		s->name		= "SC2692";
793 		s->uart.nr	= 2;
794 		s->freq_std	= 3686400;
795 		s->addr_mask	= 0x0f;
796 		s->flags	= SCCNXP_HAVE_IO;
797 		fifosize	= 3;
798 		freq_min	= 1000000;
799 		freq_max	= 4000000;
800 		break;
801 	case SCCNXP_TYPE_SC2891:
802 		s->name		= "SC2891";
803 		s->uart.nr	= 1;
804 		s->freq_std	= 3686400;
805 		s->addr_mask	= 0x0f;
806 		s->flags	= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0;
807 		fifosize	= 16;
808 		freq_min	= 100000;
809 		freq_max	= 8000000;
810 		break;
811 	case SCCNXP_TYPE_SC2892:
812 		s->name		= "SC2892";
813 		s->uart.nr	= 2;
814 		s->freq_std	= 3686400;
815 		s->addr_mask	= 0x0f;
816 		s->flags	= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0;
817 		fifosize	= 16;
818 		freq_min	= 100000;
819 		freq_max	= 8000000;
820 		break;
821 	case SCCNXP_TYPE_SC28202:
822 		s->name		= "SC28202";
823 		s->uart.nr	= 2;
824 		s->freq_std	= 14745600;
825 		s->addr_mask	= 0x7f;
826 		s->flags	= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0;
827 		fifosize	= 256;
828 		freq_min	= 1000000;
829 		freq_max	= 50000000;
830 		break;
831 	case SCCNXP_TYPE_SC68681:
832 		s->name		= "SC68681";
833 		s->uart.nr	= 2;
834 		s->freq_std	= 3686400;
835 		s->addr_mask	= 0x0f;
836 		s->flags	= SCCNXP_HAVE_IO;
837 		fifosize	= 3;
838 		freq_min	= 1000000;
839 		freq_max	= 4000000;
840 		break;
841 	case SCCNXP_TYPE_SC68692:
842 		s->name		= "SC68692";
843 		s->uart.nr	= 2;
844 		s->freq_std	= 3686400;
845 		s->addr_mask	= 0x0f;
846 		s->flags	= SCCNXP_HAVE_IO;
847 		fifosize	= 3;
848 		freq_min	= 1000000;
849 		freq_max	= 4000000;
850 		break;
851 	default:
852 		dev_err(&pdev->dev, "Unsupported chip type %i\n", chiptype);
853 		ret = -ENOTSUPP;
854 		goto err_out;
855 	}
856 
857 	if (!pdata) {
858 		dev_warn(&pdev->dev,
859 			 "No platform data supplied, using defaults\n");
860 		s->pdata.frequency = s->freq_std;
861 	} else
862 		memcpy(&s->pdata, pdata, sizeof(struct sccnxp_pdata));
863 
864 	s->irq = platform_get_irq(pdev, 0);
865 	if (s->irq <= 0) {
866 		dev_err(&pdev->dev, "Missing irq resource data\n");
867 		ret = -ENXIO;
868 		goto err_out;
869 	}
870 
871 	/* Check input frequency */
872 	if ((s->pdata.frequency < freq_min) ||
873 	    (s->pdata.frequency > freq_max)) {
874 		dev_err(&pdev->dev, "Frequency out of bounds\n");
875 		ret = -EINVAL;
876 		goto err_out;
877 	}
878 
879 	membase = devm_ioremap_resource(&pdev->dev, res);
880 	if (IS_ERR(membase)) {
881 		ret = PTR_ERR(membase);
882 		goto err_out;
883 	}
884 
885 	s->uart.owner		= THIS_MODULE;
886 	s->uart.dev_name	= "ttySC";
887 	s->uart.major		= SCCNXP_MAJOR;
888 	s->uart.minor		= SCCNXP_MINOR;
889 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
890 	s->uart.cons		= &s->console;
891 	s->uart.cons->device	= uart_console_device;
892 	s->uart.cons->write	= sccnxp_console_write;
893 	s->uart.cons->setup	= sccnxp_console_setup;
894 	s->uart.cons->flags	= CON_PRINTBUFFER;
895 	s->uart.cons->index	= -1;
896 	s->uart.cons->data	= s;
897 	strcpy(s->uart.cons->name, "ttySC");
898 #endif
899 	ret = uart_register_driver(&s->uart);
900 	if (ret) {
901 		dev_err(&pdev->dev, "Registering UART driver failed\n");
902 		goto err_out;
903 	}
904 
905 	for (i = 0; i < s->uart.nr; i++) {
906 		s->port[i].line		= i;
907 		s->port[i].dev		= &pdev->dev;
908 		s->port[i].irq		= s->irq;
909 		s->port[i].type		= PORT_SC26XX;
910 		s->port[i].fifosize	= fifosize;
911 		s->port[i].flags	= UPF_SKIP_TEST | UPF_FIXED_TYPE;
912 		s->port[i].iotype	= UPIO_MEM;
913 		s->port[i].mapbase	= res->start;
914 		s->port[i].membase	= membase;
915 		s->port[i].regshift	= s->pdata.reg_shift;
916 		s->port[i].uartclk	= s->pdata.frequency;
917 		s->port[i].ops		= &sccnxp_ops;
918 		uart_add_one_port(&s->uart, &s->port[i]);
919 		/* Set direction to input */
920 		if (s->flags & SCCNXP_HAVE_IO)
921 			sccnxp_set_bit(&s->port[i], DIR_OP, 0);
922 	}
923 
924 	/* Disable interrupts */
925 	s->imr = 0;
926 	sccnxp_write(&s->port[0], SCCNXP_IMR_REG, 0);
927 
928 	/* Board specific configure */
929 	if (s->pdata.init)
930 		s->pdata.init();
931 
932 	ret = devm_request_threaded_irq(&pdev->dev, s->irq, NULL, sccnxp_ist,
933 					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
934 					dev_name(&pdev->dev), s);
935 	if (!ret)
936 		return 0;
937 
938 	dev_err(&pdev->dev, "Unable to reguest IRQ %i\n", s->irq);
939 
940 err_out:
941 	platform_set_drvdata(pdev, NULL);
942 
943 	return ret;
944 }
945 
946 static int sccnxp_remove(struct platform_device *pdev)
947 {
948 	int i;
949 	struct sccnxp_port *s = platform_get_drvdata(pdev);
950 
951 	devm_free_irq(&pdev->dev, s->irq, s);
952 
953 	for (i = 0; i < s->uart.nr; i++)
954 		uart_remove_one_port(&s->uart, &s->port[i]);
955 
956 	uart_unregister_driver(&s->uart);
957 	platform_set_drvdata(pdev, NULL);
958 
959 	if (s->pdata.exit)
960 		s->pdata.exit();
961 
962 	return 0;
963 }
964 
965 static const struct platform_device_id sccnxp_id_table[] = {
966 	{ "sc2681",	SCCNXP_TYPE_SC2681 },
967 	{ "sc2691",	SCCNXP_TYPE_SC2691 },
968 	{ "sc2692",	SCCNXP_TYPE_SC2692 },
969 	{ "sc2891",	SCCNXP_TYPE_SC2891 },
970 	{ "sc2892",	SCCNXP_TYPE_SC2892 },
971 	{ "sc28202",	SCCNXP_TYPE_SC28202 },
972 	{ "sc68681",	SCCNXP_TYPE_SC68681 },
973 	{ "sc68692",	SCCNXP_TYPE_SC68692 },
974 	{ },
975 };
976 MODULE_DEVICE_TABLE(platform, sccnxp_id_table);
977 
978 static struct platform_driver sccnxp_uart_driver = {
979 	.driver = {
980 		.name	= SCCNXP_NAME,
981 		.owner	= THIS_MODULE,
982 	},
983 	.probe		= sccnxp_probe,
984 	.remove		= sccnxp_remove,
985 	.id_table	= sccnxp_id_table,
986 };
987 module_platform_driver(sccnxp_uart_driver);
988 
989 MODULE_LICENSE("GPL v2");
990 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
991 MODULE_DESCRIPTION("SCCNXP serial driver");
992