xref: /openbmc/linux/drivers/tty/serial/sccnxp.c (revision 4bbed6bc)
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/module.h>
19 #include <linux/device.h>
20 #include <linux/console.h>
21 #include <linux/serial_core.h>
22 #include <linux/serial.h>
23 #include <linux/io.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/spinlock.h>
27 #include <linux/platform_device.h>
28 #include <linux/platform_data/serial-sccnxp.h>
29 
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 	bool			opened[SCCNXP_MAX_UARTS];
111 
112 	const char		*name;
113 	int			irq;
114 
115 	u8			imr;
116 	u8			addr_mask;
117 	int			freq_std;
118 
119 	int			flags;
120 #define SCCNXP_HAVE_IO		0x00000001
121 #define SCCNXP_HAVE_MR0		0x00000002
122 
123 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
124 	struct console		console;
125 #endif
126 
127 	spinlock_t		lock;
128 
129 	bool			poll;
130 	struct timer_list	timer;
131 
132 	struct sccnxp_pdata	pdata;
133 };
134 
135 static inline u8 sccnxp_raw_read(void __iomem *base, u8 reg, u8 shift)
136 {
137 	return readb(base + (reg << shift));
138 }
139 
140 static inline void sccnxp_raw_write(void __iomem *base, u8 reg, u8 shift, u8 v)
141 {
142 	writeb(v, base + (reg << shift));
143 }
144 
145 static inline u8 sccnxp_read(struct uart_port *port, u8 reg)
146 {
147 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
148 
149 	return sccnxp_raw_read(port->membase, reg & s->addr_mask,
150 			       port->regshift);
151 }
152 
153 static inline void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
154 {
155 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
156 
157 	sccnxp_raw_write(port->membase, reg & s->addr_mask, port->regshift, v);
158 }
159 
160 static inline u8 sccnxp_port_read(struct uart_port *port, u8 reg)
161 {
162 	return sccnxp_read(port, (port->line << 3) + reg);
163 }
164 
165 static inline void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
166 {
167 	sccnxp_write(port, (port->line << 3) + reg, v);
168 }
169 
170 static int sccnxp_update_best_err(int a, int b, int *besterr)
171 {
172 	int err = abs(a - b);
173 
174 	if ((*besterr < 0) || (*besterr > err)) {
175 		*besterr = err;
176 		return 0;
177 	}
178 
179 	return 1;
180 }
181 
182 static const struct {
183 	u8	csr;
184 	u8	acr;
185 	u8	mr0;
186 	int	baud;
187 } baud_std[] = {
188 	{ 0,	ACR_BAUD0,	MR0_BAUD_NORMAL,	50, },
189 	{ 0,	ACR_BAUD1,	MR0_BAUD_NORMAL,	75, },
190 	{ 1,	ACR_BAUD0,	MR0_BAUD_NORMAL,	110, },
191 	{ 2,	ACR_BAUD0,	MR0_BAUD_NORMAL,	134, },
192 	{ 3,	ACR_BAUD1,	MR0_BAUD_NORMAL,	150, },
193 	{ 3,	ACR_BAUD0,	MR0_BAUD_NORMAL,	200, },
194 	{ 4,	ACR_BAUD0,	MR0_BAUD_NORMAL,	300, },
195 	{ 0,	ACR_BAUD1,	MR0_BAUD_EXT1,		450, },
196 	{ 1,	ACR_BAUD0,	MR0_BAUD_EXT2,		880, },
197 	{ 3,	ACR_BAUD1,	MR0_BAUD_EXT1,		900, },
198 	{ 5,	ACR_BAUD0,	MR0_BAUD_NORMAL,	600, },
199 	{ 7,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1050, },
200 	{ 2,	ACR_BAUD0,	MR0_BAUD_EXT2,		1076, },
201 	{ 6,	ACR_BAUD0,	MR0_BAUD_NORMAL,	1200, },
202 	{ 10,	ACR_BAUD1,	MR0_BAUD_NORMAL,	1800, },
203 	{ 7,	ACR_BAUD1,	MR0_BAUD_NORMAL,	2000, },
204 	{ 8,	ACR_BAUD0,	MR0_BAUD_NORMAL,	2400, },
205 	{ 5,	ACR_BAUD1,	MR0_BAUD_EXT1,		3600, },
206 	{ 9,	ACR_BAUD0,	MR0_BAUD_NORMAL,	4800, },
207 	{ 10,	ACR_BAUD0,	MR0_BAUD_NORMAL,	7200, },
208 	{ 11,	ACR_BAUD0,	MR0_BAUD_NORMAL,	9600, },
209 	{ 8,	ACR_BAUD0,	MR0_BAUD_EXT1,		14400, },
210 	{ 12,	ACR_BAUD1,	MR0_BAUD_NORMAL,	19200, },
211 	{ 9,	ACR_BAUD0,	MR0_BAUD_EXT1,		28800, },
212 	{ 12,	ACR_BAUD0,	MR0_BAUD_NORMAL,	38400, },
213 	{ 11,	ACR_BAUD0,	MR0_BAUD_EXT1,		57600, },
214 	{ 12,	ACR_BAUD1,	MR0_BAUD_EXT1,		115200, },
215 	{ 12,	ACR_BAUD0,	MR0_BAUD_EXT1,		230400, },
216 	{ 0, 0, 0, 0 }
217 };
218 
219 static int sccnxp_set_baud(struct uart_port *port, int baud)
220 {
221 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
222 	int div_std, tmp_baud, bestbaud = baud, besterr = -1;
223 	u8 i, acr = 0, csr = 0, mr0 = 0;
224 
225 	/* Find best baud from table */
226 	for (i = 0; baud_std[i].baud && besterr; i++) {
227 		if (baud_std[i].mr0 && !(s->flags & SCCNXP_HAVE_MR0))
228 			continue;
229 		div_std = DIV_ROUND_CLOSEST(s->freq_std, baud_std[i].baud);
230 		tmp_baud = DIV_ROUND_CLOSEST(port->uartclk, div_std);
231 		if (!sccnxp_update_best_err(baud, tmp_baud, &besterr)) {
232 			acr = baud_std[i].acr;
233 			csr = baud_std[i].csr;
234 			mr0 = baud_std[i].mr0;
235 			bestbaud = tmp_baud;
236 		}
237 	}
238 
239 	if (s->flags & SCCNXP_HAVE_MR0) {
240 		/* Enable FIFO, set half level for TX */
241 		mr0 |= MR0_FIFO | MR0_TXLVL;
242 		/* Update MR0 */
243 		sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR0);
244 		sccnxp_port_write(port, SCCNXP_MR_REG, mr0);
245 	}
246 
247 	sccnxp_port_write(port, SCCNXP_ACR_REG, acr | ACR_TIMER_MODE);
248 	sccnxp_port_write(port, SCCNXP_CSR_REG, (csr << 4) | csr);
249 
250 	if (baud != bestbaud)
251 		dev_dbg(port->dev, "Baudrate desired: %i, calculated: %i\n",
252 			baud, bestbaud);
253 
254 	return bestbaud;
255 }
256 
257 static void sccnxp_enable_irq(struct uart_port *port, int mask)
258 {
259 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
260 
261 	s->imr |= mask << (port->line * 4);
262 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
263 }
264 
265 static void sccnxp_disable_irq(struct uart_port *port, int mask)
266 {
267 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
268 
269 	s->imr &= ~(mask << (port->line * 4));
270 	sccnxp_write(port, SCCNXP_IMR_REG, s->imr);
271 }
272 
273 static void sccnxp_set_bit(struct uart_port *port, int sig, int state)
274 {
275 	u8 bitmask;
276 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
277 
278 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(sig)) {
279 		bitmask = 1 << MCTRL_OBIT(s->pdata.mctrl_cfg[port->line], sig);
280 		if (state)
281 			sccnxp_write(port, SCCNXP_SOP_REG, bitmask);
282 		else
283 			sccnxp_write(port, SCCNXP_ROP_REG, bitmask);
284 	}
285 }
286 
287 static void sccnxp_handle_rx(struct uart_port *port)
288 {
289 	u8 sr;
290 	unsigned int ch, flag;
291 
292 	for (;;) {
293 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
294 		if (!(sr & SR_RXRDY))
295 			break;
296 		sr &= SR_PE | SR_FE | SR_OVR | SR_BRK;
297 
298 		ch = sccnxp_port_read(port, SCCNXP_RHR_REG);
299 
300 		port->icount.rx++;
301 		flag = TTY_NORMAL;
302 
303 		if (unlikely(sr)) {
304 			if (sr & SR_BRK) {
305 				port->icount.brk++;
306 				sccnxp_port_write(port, SCCNXP_CR_REG,
307 						  CR_CMD_BREAK_RESET);
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 				sccnxp_port_write(port, SCCNXP_CR_REG,
317 						  CR_CMD_STATUS_RESET);
318 			}
319 
320 			sr &= port->read_status_mask;
321 			if (sr & SR_BRK)
322 				flag = TTY_BREAK;
323 			else if (sr & SR_PE)
324 				flag = TTY_PARITY;
325 			else if (sr & SR_FE)
326 				flag = TTY_FRAME;
327 			else if (sr & SR_OVR)
328 				flag = TTY_OVERRUN;
329 		}
330 
331 		if (uart_handle_sysrq_char(port, ch))
332 			continue;
333 
334 		if (sr & port->ignore_status_mask)
335 			continue;
336 
337 		uart_insert_char(port, sr, SR_OVR, ch, flag);
338 	}
339 
340 	tty_flip_buffer_push(&port->state->port);
341 }
342 
343 static void sccnxp_handle_tx(struct uart_port *port)
344 {
345 	u8 sr;
346 	struct circ_buf *xmit = &port->state->xmit;
347 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
348 
349 	if (unlikely(port->x_char)) {
350 		sccnxp_port_write(port, SCCNXP_THR_REG, port->x_char);
351 		port->icount.tx++;
352 		port->x_char = 0;
353 		return;
354 	}
355 
356 	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
357 		/* Disable TX if FIFO is empty */
358 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXEMT) {
359 			sccnxp_disable_irq(port, IMR_TXRDY);
360 
361 			/* Set direction to input */
362 			if (s->flags & SCCNXP_HAVE_IO)
363 				sccnxp_set_bit(port, DIR_OP, 0);
364 		}
365 		return;
366 	}
367 
368 	while (!uart_circ_empty(xmit)) {
369 		sr = sccnxp_port_read(port, SCCNXP_SR_REG);
370 		if (!(sr & SR_TXRDY))
371 			break;
372 
373 		sccnxp_port_write(port, SCCNXP_THR_REG, xmit->buf[xmit->tail]);
374 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
375 		port->icount.tx++;
376 	}
377 
378 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
379 		uart_write_wakeup(port);
380 }
381 
382 static void sccnxp_handle_events(struct sccnxp_port *s)
383 {
384 	int i;
385 	u8 isr;
386 
387 	do {
388 		isr = sccnxp_read(&s->port[0], SCCNXP_ISR_REG);
389 		isr &= s->imr;
390 		if (!isr)
391 			break;
392 
393 		for (i = 0; i < s->uart.nr; i++) {
394 			if (s->opened[i] && (isr & ISR_RXRDY(i)))
395 				sccnxp_handle_rx(&s->port[i]);
396 			if (s->opened[i] && (isr & ISR_TXRDY(i)))
397 				sccnxp_handle_tx(&s->port[i]);
398 		}
399 	} while (1);
400 }
401 
402 static void sccnxp_timer(unsigned long data)
403 {
404 	struct sccnxp_port *s = (struct sccnxp_port *)data;
405 	unsigned long flags;
406 
407 	spin_lock_irqsave(&s->lock, flags);
408 	sccnxp_handle_events(s);
409 	spin_unlock_irqrestore(&s->lock, flags);
410 
411 	if (!timer_pending(&s->timer))
412 		mod_timer(&s->timer, jiffies +
413 			  usecs_to_jiffies(s->pdata.poll_time_us));
414 }
415 
416 static irqreturn_t sccnxp_ist(int irq, void *dev_id)
417 {
418 	struct sccnxp_port *s = (struct sccnxp_port *)dev_id;
419 	unsigned long flags;
420 
421 	spin_lock_irqsave(&s->lock, flags);
422 	sccnxp_handle_events(s);
423 	spin_unlock_irqrestore(&s->lock, flags);
424 
425 	return IRQ_HANDLED;
426 }
427 
428 static void sccnxp_start_tx(struct uart_port *port)
429 {
430 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
431 	unsigned long flags;
432 
433 	spin_lock_irqsave(&s->lock, flags);
434 
435 	/* Set direction to output */
436 	if (s->flags & SCCNXP_HAVE_IO)
437 		sccnxp_set_bit(port, DIR_OP, 1);
438 
439 	sccnxp_enable_irq(port, IMR_TXRDY);
440 
441 	spin_unlock_irqrestore(&s->lock, flags);
442 }
443 
444 static void sccnxp_stop_tx(struct uart_port *port)
445 {
446 	/* Do nothing */
447 }
448 
449 static void sccnxp_stop_rx(struct uart_port *port)
450 {
451 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
452 	unsigned long flags;
453 
454 	spin_lock_irqsave(&s->lock, flags);
455 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE);
456 	spin_unlock_irqrestore(&s->lock, flags);
457 }
458 
459 static unsigned int sccnxp_tx_empty(struct uart_port *port)
460 {
461 	u8 val;
462 	unsigned long flags;
463 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
464 
465 	spin_lock_irqsave(&s->lock, flags);
466 	val = sccnxp_port_read(port, SCCNXP_SR_REG);
467 	spin_unlock_irqrestore(&s->lock, flags);
468 
469 	return (val & SR_TXEMT) ? TIOCSER_TEMT : 0;
470 }
471 
472 static void sccnxp_enable_ms(struct uart_port *port)
473 {
474 	/* Do nothing */
475 }
476 
477 static void sccnxp_set_mctrl(struct uart_port *port, unsigned int mctrl)
478 {
479 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
480 	unsigned long flags;
481 
482 	if (!(s->flags & SCCNXP_HAVE_IO))
483 		return;
484 
485 	spin_lock_irqsave(&s->lock, flags);
486 
487 	sccnxp_set_bit(port, DTR_OP, mctrl & TIOCM_DTR);
488 	sccnxp_set_bit(port, RTS_OP, mctrl & TIOCM_RTS);
489 
490 	spin_unlock_irqrestore(&s->lock, flags);
491 }
492 
493 static unsigned int sccnxp_get_mctrl(struct uart_port *port)
494 {
495 	u8 bitmask, ipr;
496 	unsigned long flags;
497 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
498 	unsigned int mctrl = TIOCM_DSR | TIOCM_CTS | TIOCM_CAR;
499 
500 	if (!(s->flags & SCCNXP_HAVE_IO))
501 		return mctrl;
502 
503 	spin_lock_irqsave(&s->lock, flags);
504 
505 	ipr = ~sccnxp_read(port, SCCNXP_IPCR_REG);
506 
507 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DSR_IP)) {
508 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
509 					  DSR_IP);
510 		mctrl &= ~TIOCM_DSR;
511 		mctrl |= (ipr & bitmask) ? TIOCM_DSR : 0;
512 	}
513 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(CTS_IP)) {
514 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
515 					  CTS_IP);
516 		mctrl &= ~TIOCM_CTS;
517 		mctrl |= (ipr & bitmask) ? TIOCM_CTS : 0;
518 	}
519 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(DCD_IP)) {
520 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
521 					  DCD_IP);
522 		mctrl &= ~TIOCM_CAR;
523 		mctrl |= (ipr & bitmask) ? TIOCM_CAR : 0;
524 	}
525 	if (s->pdata.mctrl_cfg[port->line] & MCTRL_MASK(RNG_IP)) {
526 		bitmask = 1 << MCTRL_IBIT(s->pdata.mctrl_cfg[port->line],
527 					  RNG_IP);
528 		mctrl &= ~TIOCM_RNG;
529 		mctrl |= (ipr & bitmask) ? TIOCM_RNG : 0;
530 	}
531 
532 	spin_unlock_irqrestore(&s->lock, flags);
533 
534 	return mctrl;
535 }
536 
537 static void sccnxp_break_ctl(struct uart_port *port, int break_state)
538 {
539 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
540 	unsigned long flags;
541 
542 	spin_lock_irqsave(&s->lock, flags);
543 	sccnxp_port_write(port, SCCNXP_CR_REG, break_state ?
544 			  CR_CMD_START_BREAK : CR_CMD_STOP_BREAK);
545 	spin_unlock_irqrestore(&s->lock, flags);
546 }
547 
548 static void sccnxp_set_termios(struct uart_port *port,
549 			       struct ktermios *termios, struct ktermios *old)
550 {
551 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
552 	unsigned long flags;
553 	u8 mr1, mr2;
554 	int baud;
555 
556 	spin_lock_irqsave(&s->lock, flags);
557 
558 	/* Mask termios capabilities we don't support */
559 	termios->c_cflag &= ~CMSPAR;
560 
561 	/* Disable RX & TX, reset break condition, status and FIFOs */
562 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET |
563 					       CR_RX_DISABLE | CR_TX_DISABLE);
564 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
565 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
566 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
567 
568 	/* Word size */
569 	switch (termios->c_cflag & CSIZE) {
570 	case CS5:
571 		mr1 = MR1_BITS_5;
572 		break;
573 	case CS6:
574 		mr1 = MR1_BITS_6;
575 		break;
576 	case CS7:
577 		mr1 = MR1_BITS_7;
578 		break;
579 	case CS8:
580 	default:
581 		mr1 = MR1_BITS_8;
582 		break;
583 	}
584 
585 	/* Parity */
586 	if (termios->c_cflag & PARENB) {
587 		if (termios->c_cflag & PARODD)
588 			mr1 |= MR1_PAR_ODD;
589 	} else
590 		mr1 |= MR1_PAR_NO;
591 
592 	/* Stop bits */
593 	mr2 = (termios->c_cflag & CSTOPB) ? MR2_STOP2 : MR2_STOP1;
594 
595 	/* Update desired format */
596 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_MRPTR1);
597 	sccnxp_port_write(port, SCCNXP_MR_REG, mr1);
598 	sccnxp_port_write(port, SCCNXP_MR_REG, mr2);
599 
600 	/* Set read status mask */
601 	port->read_status_mask = SR_OVR;
602 	if (termios->c_iflag & INPCK)
603 		port->read_status_mask |= SR_PE | SR_FE;
604 	if (termios->c_iflag & (BRKINT | PARMRK))
605 		port->read_status_mask |= SR_BRK;
606 
607 	/* Set status ignore mask */
608 	port->ignore_status_mask = 0;
609 	if (termios->c_iflag & IGNBRK)
610 		port->ignore_status_mask |= SR_BRK;
611 	if (!(termios->c_cflag & CREAD))
612 		port->ignore_status_mask |= SR_PE | SR_OVR | SR_FE | SR_BRK;
613 
614 	/* Setup baudrate */
615 	baud = uart_get_baud_rate(port, termios, old, 50,
616 				  (s->flags & SCCNXP_HAVE_MR0) ?
617 				  230400 : 38400);
618 	baud = sccnxp_set_baud(port, baud);
619 
620 	/* Update timeout according to new baud rate */
621 	uart_update_timeout(port, termios->c_cflag, baud);
622 
623 	/* Report actual baudrate back to core */
624 	if (tty_termios_baud_rate(termios))
625 		tty_termios_encode_baud_rate(termios, baud, baud);
626 
627 	/* Enable RX & TX */
628 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
629 
630 	spin_unlock_irqrestore(&s->lock, flags);
631 }
632 
633 static int sccnxp_startup(struct uart_port *port)
634 {
635 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
636 	unsigned long flags;
637 
638 	spin_lock_irqsave(&s->lock, flags);
639 
640 	if (s->flags & SCCNXP_HAVE_IO) {
641 		/* Outputs are controlled manually */
642 		sccnxp_write(port, SCCNXP_OPCR_REG, 0);
643 	}
644 
645 	/* Reset break condition, status and FIFOs */
646 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_RX_RESET);
647 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_TX_RESET);
648 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_STATUS_RESET);
649 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_CMD_BREAK_RESET);
650 
651 	/* Enable RX & TX */
652 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_ENABLE | CR_TX_ENABLE);
653 
654 	/* Enable RX interrupt */
655 	sccnxp_enable_irq(port, IMR_RXRDY);
656 
657 	s->opened[port->line] = 1;
658 
659 	spin_unlock_irqrestore(&s->lock, flags);
660 
661 	return 0;
662 }
663 
664 static void sccnxp_shutdown(struct uart_port *port)
665 {
666 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
667 	unsigned long flags;
668 
669 	spin_lock_irqsave(&s->lock, flags);
670 
671 	s->opened[port->line] = 0;
672 
673 	/* Disable interrupts */
674 	sccnxp_disable_irq(port, IMR_TXRDY | IMR_RXRDY);
675 
676 	/* Disable TX & RX */
677 	sccnxp_port_write(port, SCCNXP_CR_REG, CR_RX_DISABLE | CR_TX_DISABLE);
678 
679 	/* Leave direction to input */
680 	if (s->flags & SCCNXP_HAVE_IO)
681 		sccnxp_set_bit(port, DIR_OP, 0);
682 
683 	spin_unlock_irqrestore(&s->lock, flags);
684 }
685 
686 static const char *sccnxp_type(struct uart_port *port)
687 {
688 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
689 
690 	return (port->type == PORT_SC26XX) ? s->name : NULL;
691 }
692 
693 static void sccnxp_release_port(struct uart_port *port)
694 {
695 	/* Do nothing */
696 }
697 
698 static int sccnxp_request_port(struct uart_port *port)
699 {
700 	/* Do nothing */
701 	return 0;
702 }
703 
704 static void sccnxp_config_port(struct uart_port *port, int flags)
705 {
706 	if (flags & UART_CONFIG_TYPE)
707 		port->type = PORT_SC26XX;
708 }
709 
710 static int sccnxp_verify_port(struct uart_port *port, struct serial_struct *s)
711 {
712 	if ((s->type == PORT_UNKNOWN) || (s->type == PORT_SC26XX))
713 		return 0;
714 	if (s->irq == port->irq)
715 		return 0;
716 
717 	return -EINVAL;
718 }
719 
720 static const struct uart_ops sccnxp_ops = {
721 	.tx_empty	= sccnxp_tx_empty,
722 	.set_mctrl	= sccnxp_set_mctrl,
723 	.get_mctrl	= sccnxp_get_mctrl,
724 	.stop_tx	= sccnxp_stop_tx,
725 	.start_tx	= sccnxp_start_tx,
726 	.stop_rx	= sccnxp_stop_rx,
727 	.enable_ms	= sccnxp_enable_ms,
728 	.break_ctl	= sccnxp_break_ctl,
729 	.startup	= sccnxp_startup,
730 	.shutdown	= sccnxp_shutdown,
731 	.set_termios	= sccnxp_set_termios,
732 	.type		= sccnxp_type,
733 	.release_port	= sccnxp_release_port,
734 	.request_port	= sccnxp_request_port,
735 	.config_port	= sccnxp_config_port,
736 	.verify_port	= sccnxp_verify_port,
737 };
738 
739 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
740 static void sccnxp_console_putchar(struct uart_port *port, int c)
741 {
742 	int tryes = 100000;
743 
744 	while (tryes--) {
745 		if (sccnxp_port_read(port, SCCNXP_SR_REG) & SR_TXRDY) {
746 			sccnxp_port_write(port, SCCNXP_THR_REG, c);
747 			break;
748 		}
749 		barrier();
750 	}
751 }
752 
753 static void sccnxp_console_write(struct console *co, const char *c, unsigned n)
754 {
755 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
756 	struct uart_port *port = &s->port[co->index];
757 	unsigned long flags;
758 
759 	spin_lock_irqsave(&s->lock, flags);
760 	uart_console_write(port, c, n, sccnxp_console_putchar);
761 	spin_unlock_irqrestore(&s->lock, flags);
762 }
763 
764 static int sccnxp_console_setup(struct console *co, char *options)
765 {
766 	struct sccnxp_port *s = (struct sccnxp_port *)co->data;
767 	struct uart_port *port = &s->port[(co->index > 0) ? co->index : 0];
768 	int baud = 9600, bits = 8, parity = 'n', flow = 'n';
769 
770 	if (options)
771 		uart_parse_options(options, &baud, &parity, &bits, &flow);
772 
773 	return uart_set_options(port, co, baud, parity, bits, flow);
774 }
775 #endif
776 
777 static int sccnxp_probe(struct platform_device *pdev)
778 {
779 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
780 	int chiptype = pdev->id_entry->driver_data;
781 	struct sccnxp_pdata *pdata = dev_get_platdata(&pdev->dev);
782 	int i, ret, fifosize, freq_min, freq_max;
783 	struct sccnxp_port *s;
784 	void __iomem *membase;
785 
786 	if (!res) {
787 		dev_err(&pdev->dev, "Missing memory resource data\n");
788 		return -EADDRNOTAVAIL;
789 	}
790 
791 	dev_set_name(&pdev->dev, SCCNXP_NAME);
792 
793 	s = devm_kzalloc(&pdev->dev, sizeof(struct sccnxp_port), GFP_KERNEL);
794 	if (!s) {
795 		dev_err(&pdev->dev, "Error allocating port structure\n");
796 		return -ENOMEM;
797 	}
798 	platform_set_drvdata(pdev, s);
799 
800 	spin_lock_init(&s->lock);
801 
802 	/* Individual chip settings */
803 	switch (chiptype) {
804 	case SCCNXP_TYPE_SC2681:
805 		s->name		= "SC2681";
806 		s->uart.nr	= 2;
807 		s->freq_std	= 3686400;
808 		s->addr_mask	= 0x0f;
809 		s->flags	= SCCNXP_HAVE_IO;
810 		fifosize	= 3;
811 		freq_min	= 1000000;
812 		freq_max	= 4000000;
813 		break;
814 	case SCCNXP_TYPE_SC2691:
815 		s->name		= "SC2691";
816 		s->uart.nr	= 1;
817 		s->freq_std	= 3686400;
818 		s->addr_mask	= 0x07;
819 		s->flags	= 0;
820 		fifosize	= 3;
821 		freq_min	= 1000000;
822 		freq_max	= 4000000;
823 		break;
824 	case SCCNXP_TYPE_SC2692:
825 		s->name		= "SC2692";
826 		s->uart.nr	= 2;
827 		s->freq_std	= 3686400;
828 		s->addr_mask	= 0x0f;
829 		s->flags	= SCCNXP_HAVE_IO;
830 		fifosize	= 3;
831 		freq_min	= 1000000;
832 		freq_max	= 4000000;
833 		break;
834 	case SCCNXP_TYPE_SC2891:
835 		s->name		= "SC2891";
836 		s->uart.nr	= 1;
837 		s->freq_std	= 3686400;
838 		s->addr_mask	= 0x0f;
839 		s->flags	= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0;
840 		fifosize	= 16;
841 		freq_min	= 100000;
842 		freq_max	= 8000000;
843 		break;
844 	case SCCNXP_TYPE_SC2892:
845 		s->name		= "SC2892";
846 		s->uart.nr	= 2;
847 		s->freq_std	= 3686400;
848 		s->addr_mask	= 0x0f;
849 		s->flags	= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0;
850 		fifosize	= 16;
851 		freq_min	= 100000;
852 		freq_max	= 8000000;
853 		break;
854 	case SCCNXP_TYPE_SC28202:
855 		s->name		= "SC28202";
856 		s->uart.nr	= 2;
857 		s->freq_std	= 14745600;
858 		s->addr_mask	= 0x7f;
859 		s->flags	= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0;
860 		fifosize	= 256;
861 		freq_min	= 1000000;
862 		freq_max	= 50000000;
863 		break;
864 	case SCCNXP_TYPE_SC68681:
865 		s->name		= "SC68681";
866 		s->uart.nr	= 2;
867 		s->freq_std	= 3686400;
868 		s->addr_mask	= 0x0f;
869 		s->flags	= SCCNXP_HAVE_IO;
870 		fifosize	= 3;
871 		freq_min	= 1000000;
872 		freq_max	= 4000000;
873 		break;
874 	case SCCNXP_TYPE_SC68692:
875 		s->name		= "SC68692";
876 		s->uart.nr	= 2;
877 		s->freq_std	= 3686400;
878 		s->addr_mask	= 0x0f;
879 		s->flags	= SCCNXP_HAVE_IO;
880 		fifosize	= 3;
881 		freq_min	= 1000000;
882 		freq_max	= 4000000;
883 		break;
884 	default:
885 		dev_err(&pdev->dev, "Unsupported chip type %i\n", chiptype);
886 		ret = -ENOTSUPP;
887 		goto err_out;
888 	}
889 
890 	if (!pdata) {
891 		dev_warn(&pdev->dev,
892 			 "No platform data supplied, using defaults\n");
893 		s->pdata.frequency = s->freq_std;
894 	} else
895 		memcpy(&s->pdata, pdata, sizeof(struct sccnxp_pdata));
896 
897 	if (s->pdata.poll_time_us) {
898 		dev_info(&pdev->dev, "Using poll mode, resolution %u usecs\n",
899 			 s->pdata.poll_time_us);
900 		s->poll = 1;
901 	}
902 
903 	if (!s->poll) {
904 		s->irq = platform_get_irq(pdev, 0);
905 		if (s->irq < 0) {
906 			dev_err(&pdev->dev, "Missing irq resource data\n");
907 			ret = -ENXIO;
908 			goto err_out;
909 		}
910 	}
911 
912 	/* Check input frequency */
913 	if ((s->pdata.frequency < freq_min) ||
914 	    (s->pdata.frequency > freq_max)) {
915 		dev_err(&pdev->dev, "Frequency out of bounds\n");
916 		ret = -EINVAL;
917 		goto err_out;
918 	}
919 
920 	membase = devm_request_and_ioremap(&pdev->dev, res);
921 	if (!membase) {
922 		dev_err(&pdev->dev, "Failed to ioremap\n");
923 		ret = -EIO;
924 		goto err_out;
925 	}
926 
927 	s->uart.owner		= THIS_MODULE;
928 	s->uart.dev_name	= "ttySC";
929 	s->uart.major		= SCCNXP_MAJOR;
930 	s->uart.minor		= SCCNXP_MINOR;
931 #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
932 	s->uart.cons		= &s->console;
933 	s->uart.cons->device	= uart_console_device;
934 	s->uart.cons->write	= sccnxp_console_write;
935 	s->uart.cons->setup	= sccnxp_console_setup;
936 	s->uart.cons->flags	= CON_PRINTBUFFER;
937 	s->uart.cons->index	= -1;
938 	s->uart.cons->data	= s;
939 	strcpy(s->uart.cons->name, "ttySC");
940 #endif
941 	ret = uart_register_driver(&s->uart);
942 	if (ret) {
943 		dev_err(&pdev->dev, "Registering UART driver failed\n");
944 		goto err_out;
945 	}
946 
947 	for (i = 0; i < s->uart.nr; i++) {
948 		s->port[i].line		= i;
949 		s->port[i].dev		= &pdev->dev;
950 		s->port[i].irq		= s->irq;
951 		s->port[i].type		= PORT_SC26XX;
952 		s->port[i].fifosize	= fifosize;
953 		s->port[i].flags	= UPF_SKIP_TEST | UPF_FIXED_TYPE;
954 		s->port[i].iotype	= UPIO_MEM;
955 		s->port[i].mapbase	= res->start;
956 		s->port[i].membase	= membase;
957 		s->port[i].regshift	= s->pdata.reg_shift;
958 		s->port[i].uartclk	= s->pdata.frequency;
959 		s->port[i].ops		= &sccnxp_ops;
960 		uart_add_one_port(&s->uart, &s->port[i]);
961 		/* Set direction to input */
962 		if (s->flags & SCCNXP_HAVE_IO)
963 			sccnxp_set_bit(&s->port[i], DIR_OP, 0);
964 	}
965 
966 	/* Disable interrupts */
967 	s->imr = 0;
968 	sccnxp_write(&s->port[0], SCCNXP_IMR_REG, 0);
969 
970 	/* Board specific configure */
971 	if (s->pdata.init)
972 		s->pdata.init();
973 
974 	if (!s->poll) {
975 		ret = devm_request_threaded_irq(&pdev->dev, s->irq, NULL,
976 						sccnxp_ist,
977 						IRQF_TRIGGER_FALLING |
978 						IRQF_ONESHOT,
979 						dev_name(&pdev->dev), s);
980 		if (!ret)
981 			return 0;
982 
983 		dev_err(&pdev->dev, "Unable to reguest IRQ %i\n", s->irq);
984 	} else {
985 		init_timer(&s->timer);
986 		setup_timer(&s->timer, sccnxp_timer, (unsigned long)s);
987 		mod_timer(&s->timer, jiffies +
988 			  usecs_to_jiffies(s->pdata.poll_time_us));
989 		return 0;
990 	}
991 
992 err_out:
993 	platform_set_drvdata(pdev, NULL);
994 
995 	return ret;
996 }
997 
998 static int sccnxp_remove(struct platform_device *pdev)
999 {
1000 	int i;
1001 	struct sccnxp_port *s = platform_get_drvdata(pdev);
1002 
1003 	if (!s->poll)
1004 		devm_free_irq(&pdev->dev, s->irq, s);
1005 	else
1006 		del_timer_sync(&s->timer);
1007 
1008 	for (i = 0; i < s->uart.nr; i++)
1009 		uart_remove_one_port(&s->uart, &s->port[i]);
1010 
1011 	uart_unregister_driver(&s->uart);
1012 	platform_set_drvdata(pdev, NULL);
1013 
1014 	if (s->pdata.exit)
1015 		s->pdata.exit();
1016 
1017 	return 0;
1018 }
1019 
1020 static const struct platform_device_id sccnxp_id_table[] = {
1021 	{ "sc2681",	SCCNXP_TYPE_SC2681 },
1022 	{ "sc2691",	SCCNXP_TYPE_SC2691 },
1023 	{ "sc2692",	SCCNXP_TYPE_SC2692 },
1024 	{ "sc2891",	SCCNXP_TYPE_SC2891 },
1025 	{ "sc2892",	SCCNXP_TYPE_SC2892 },
1026 	{ "sc28202",	SCCNXP_TYPE_SC28202 },
1027 	{ "sc68681",	SCCNXP_TYPE_SC68681 },
1028 	{ "sc68692",	SCCNXP_TYPE_SC68692 },
1029 	{ },
1030 };
1031 MODULE_DEVICE_TABLE(platform, sccnxp_id_table);
1032 
1033 static struct platform_driver sccnxp_uart_driver = {
1034 	.driver = {
1035 		.name	= SCCNXP_NAME,
1036 		.owner	= THIS_MODULE,
1037 	},
1038 	.probe		= sccnxp_probe,
1039 	.remove		= sccnxp_remove,
1040 	.id_table	= sccnxp_id_table,
1041 };
1042 module_platform_driver(sccnxp_uart_driver);
1043 
1044 MODULE_LICENSE("GPL v2");
1045 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
1046 MODULE_DESCRIPTION("SCCNXP serial driver");
1047