xref: /linux/drivers/tty/serial/men_z135_uart.c (revision 0bbdb4258bd116d8cd5d209e8d5b29bae516e5b3) 
1 /*
2  * MEN 16z135 High Speed UART
3  *
4  * Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de)
5  * Author: Johannes Thumshirn <johannes.thumshirn@men.de>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published by the Free
9  * Software Foundation; version 2 of the License.
10  */
11 #define pr_fmt(fmt) KBUILD_MODNAME ":" fmt
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/interrupt.h>
16 #include <linux/serial_core.h>
17 #include <linux/ioport.h>
18 #include <linux/io.h>
19 #include <linux/tty_flip.h>
20 #include <linux/bitops.h>
21 #include <linux/mcb.h>
22 
23 #define MEN_Z135_MAX_PORTS		12
24 #define MEN_Z135_BASECLK		29491200
25 #define MEN_Z135_FIFO_SIZE		1024
26 #define MEN_Z135_FIFO_WATERMARK		1020
27 
28 #define MEN_Z135_STAT_REG		0x0
29 #define MEN_Z135_RX_RAM			0x4
30 #define MEN_Z135_TX_RAM			0x400
31 #define MEN_Z135_RX_CTRL		0x800
32 #define MEN_Z135_TX_CTRL		0x804
33 #define MEN_Z135_CONF_REG		0x808
34 #define MEN_Z135_UART_FREQ		0x80c
35 #define MEN_Z135_BAUD_REG		0x810
36 #define MEN_Z135_TIMEOUT		0x814
37 
38 #define MEN_Z135_MEM_SIZE		0x818
39 
40 #define IRQ_ID(x) ((x) & 0x1f)
41 
42 #define MEN_Z135_IER_RXCIEN BIT(0)		/* RX Space IRQ */
43 #define MEN_Z135_IER_TXCIEN BIT(1)		/* TX Space IRQ */
44 #define MEN_Z135_IER_RLSIEN BIT(2)		/* Receiver Line Status IRQ */
45 #define MEN_Z135_IER_MSIEN  BIT(3)		/* Modem Status IRQ */
46 #define MEN_Z135_ALL_IRQS (MEN_Z135_IER_RXCIEN		\
47 				| MEN_Z135_IER_RLSIEN	\
48 				| MEN_Z135_IER_MSIEN	\
49 				| MEN_Z135_IER_TXCIEN)
50 
51 #define MEN_Z135_MCR_DTR	BIT(24)
52 #define MEN_Z135_MCR_RTS	BIT(25)
53 #define MEN_Z135_MCR_OUT1	BIT(26)
54 #define MEN_Z135_MCR_OUT2	BIT(27)
55 #define MEN_Z135_MCR_LOOP	BIT(28)
56 #define MEN_Z135_MCR_RCFC	BIT(29)
57 
58 #define MEN_Z135_MSR_DCTS	BIT(0)
59 #define MEN_Z135_MSR_DDSR	BIT(1)
60 #define MEN_Z135_MSR_DRI	BIT(2)
61 #define MEN_Z135_MSR_DDCD	BIT(3)
62 #define MEN_Z135_MSR_CTS	BIT(4)
63 #define MEN_Z135_MSR_DSR	BIT(5)
64 #define MEN_Z135_MSR_RI		BIT(6)
65 #define MEN_Z135_MSR_DCD	BIT(7)
66 
67 #define MEN_Z135_LCR_SHIFT 8	/* LCR shift mask */
68 
69 #define MEN_Z135_WL5 0		/* CS5 */
70 #define MEN_Z135_WL6 1		/* CS6 */
71 #define MEN_Z135_WL7 2		/* CS7 */
72 #define MEN_Z135_WL8 3		/* CS8 */
73 
74 #define MEN_Z135_STB_SHIFT 2	/* Stopbits */
75 #define MEN_Z135_NSTB1 0
76 #define MEN_Z135_NSTB2 1
77 
78 #define MEN_Z135_PEN_SHIFT 3	/* Parity enable */
79 #define MEN_Z135_PAR_DIS 0
80 #define MEN_Z135_PAR_ENA 1
81 
82 #define MEN_Z135_PTY_SHIFT 4	/* Parity type */
83 #define MEN_Z135_PTY_ODD 0
84 #define MEN_Z135_PTY_EVN 1
85 
86 #define MEN_Z135_LSR_DR BIT(0)
87 #define MEN_Z135_LSR_OE BIT(1)
88 #define MEN_Z135_LSR_PE BIT(2)
89 #define MEN_Z135_LSR_FE BIT(3)
90 #define MEN_Z135_LSR_BI BIT(4)
91 #define MEN_Z135_LSR_THEP BIT(5)
92 #define MEN_Z135_LSR_TEXP BIT(6)
93 #define MEN_Z135_LSR_RXFIFOERR BIT(7)
94 
95 #define MEN_Z135_IRQ_ID_RLS BIT(0)
96 #define MEN_Z135_IRQ_ID_RDA BIT(1)
97 #define MEN_Z135_IRQ_ID_CTI BIT(2)
98 #define MEN_Z135_IRQ_ID_TSA BIT(3)
99 #define MEN_Z135_IRQ_ID_MST BIT(4)
100 
101 #define LCR(x) (((x) >> MEN_Z135_LCR_SHIFT) & 0xff)
102 
103 #define BYTES_TO_ALIGN(x) ((x) & 0x3)
104 
105 static int line;
106 
107 static int txlvl = 5;
108 module_param(txlvl, int, S_IRUGO);
109 MODULE_PARM_DESC(txlvl, "TX IRQ trigger level 0-7, default 5 (128 byte)");
110 
111 static int rxlvl = 6;
112 module_param(rxlvl, int, S_IRUGO);
113 MODULE_PARM_DESC(rxlvl, "RX IRQ trigger level 0-7, default 6 (256 byte)");
114 
115 static int align;
116 module_param(align, int, S_IRUGO);
117 MODULE_PARM_DESC(align, "Keep hardware FIFO write pointer aligned, default 0");
118 
119 static uint rx_timeout;
120 module_param(rx_timeout, uint, S_IRUGO);
121 MODULE_PARM_DESC(rx_timeout, "RX timeout. "
122 		"Timeout in seconds = (timeout_reg * baud_reg * 4) / freq_reg");
123 
124 struct men_z135_port {
125 	struct uart_port port;
126 	struct mcb_device *mdev;
127 	unsigned char *rxbuf;
128 	u32 stat_reg;
129 	spinlock_t lock;
130 	bool automode;
131 };
132 #define to_men_z135(port) container_of((port), struct men_z135_port, port)
133 
134 /**
135  * men_z135_reg_set() - Set value in register
136  * @uart: The UART port
137  * @addr: Register address
138  * @val: value to set
139  */
140 static inline void men_z135_reg_set(struct men_z135_port *uart,
141 				u32 addr, u32 val)
142 {
143 	struct uart_port *port = &uart->port;
144 	unsigned long flags;
145 	u32 reg;
146 
147 	spin_lock_irqsave(&uart->lock, flags);
148 
149 	reg = ioread32(port->membase + addr);
150 	reg |= val;
151 	iowrite32(reg, port->membase + addr);
152 
153 	spin_unlock_irqrestore(&uart->lock, flags);
154 }
155 
156 /**
157  * men_z135_reg_clr() - Unset value in register
158  * @uart: The UART port
159  * @addr: Register address
160  * @val: value to clear
161  */
162 static inline void men_z135_reg_clr(struct men_z135_port *uart,
163 				u32 addr, u32 val)
164 {
165 	struct uart_port *port = &uart->port;
166 	unsigned long flags;
167 	u32 reg;
168 
169 	spin_lock_irqsave(&uart->lock, flags);
170 
171 	reg = ioread32(port->membase + addr);
172 	reg &= ~val;
173 	iowrite32(reg, port->membase + addr);
174 
175 	spin_unlock_irqrestore(&uart->lock, flags);
176 }
177 
178 /**
179  * men_z135_handle_modem_status() - Handle change of modem status
180  * @port: The UART port
181  *
182  * Handle change of modem status register. This is done by reading the "delta"
183  * versions of DCD (Data Carrier Detect) and CTS (Clear To Send).
184  */
185 static void men_z135_handle_modem_status(struct men_z135_port *uart)
186 {
187 	u8 msr;
188 
189 	msr = (uart->stat_reg >> 8) & 0xff;
190 
191 	if (msr & MEN_Z135_MSR_DDCD)
192 		uart_handle_dcd_change(&uart->port,
193 				msr & MEN_Z135_MSR_DCD);
194 	if (msr & MEN_Z135_MSR_DCTS)
195 		uart_handle_cts_change(&uart->port,
196 				msr & MEN_Z135_MSR_CTS);
197 }
198 
199 static void men_z135_handle_lsr(struct men_z135_port *uart)
200 {
201 	struct uart_port *port = &uart->port;
202 	u8 lsr;
203 
204 	lsr = (uart->stat_reg >> 16) & 0xff;
205 
206 	if (lsr & MEN_Z135_LSR_OE)
207 		port->icount.overrun++;
208 	if (lsr & MEN_Z135_LSR_PE)
209 		port->icount.parity++;
210 	if (lsr & MEN_Z135_LSR_FE)
211 		port->icount.frame++;
212 	if (lsr & MEN_Z135_LSR_BI) {
213 		port->icount.brk++;
214 		uart_handle_break(port);
215 	}
216 }
217 
218 /**
219  * get_rx_fifo_content() - Get the number of bytes in RX FIFO
220  * @uart: The UART port
221  *
222  * Read RXC register from hardware and return current FIFO fill size.
223  */
224 static u16 get_rx_fifo_content(struct men_z135_port *uart)
225 {
226 	struct uart_port *port = &uart->port;
227 	u32 stat_reg;
228 	u16 rxc;
229 	u8 rxc_lo;
230 	u8 rxc_hi;
231 
232 	stat_reg = ioread32(port->membase + MEN_Z135_STAT_REG);
233 	rxc_lo = stat_reg >> 24;
234 	rxc_hi = (stat_reg & 0xC0) >> 6;
235 
236 	rxc = rxc_lo | (rxc_hi << 8);
237 
238 	return rxc;
239 }
240 
241 /**
242  * men_z135_handle_rx() - RX tasklet routine
243  * @arg: Pointer to struct men_z135_port
244  *
245  * Copy from RX FIFO and acknowledge number of bytes copied.
246  */
247 static void men_z135_handle_rx(struct men_z135_port *uart)
248 {
249 	struct uart_port *port = &uart->port;
250 	struct tty_port *tport = &port->state->port;
251 	int copied;
252 	u16 size;
253 	int room;
254 
255 	size = get_rx_fifo_content(uart);
256 
257 	if (size == 0)
258 		return;
259 
260 	/* Avoid accidently accessing TX FIFO instead of RX FIFO. Last
261 	 * longword in RX FIFO cannot be read.(0x004-0x3FF)
262 	 */
263 	if (size > MEN_Z135_FIFO_WATERMARK)
264 		size = MEN_Z135_FIFO_WATERMARK;
265 
266 	room = tty_buffer_request_room(tport, size);
267 	if (room != size)
268 		dev_warn(&uart->mdev->dev,
269 			"Not enough room in flip buffer, truncating to %d\n",
270 			room);
271 
272 	if (room == 0)
273 		return;
274 
275 	memcpy_fromio(uart->rxbuf, port->membase + MEN_Z135_RX_RAM, room);
276 	/* Be sure to first copy all data and then acknowledge it */
277 	mb();
278 	iowrite32(room, port->membase +  MEN_Z135_RX_CTRL);
279 
280 	copied = tty_insert_flip_string(tport, uart->rxbuf, room);
281 	if (copied != room)
282 		dev_warn(&uart->mdev->dev,
283 			"Only copied %d instead of %d bytes\n",
284 			copied, room);
285 
286 	port->icount.rx += copied;
287 
288 	tty_flip_buffer_push(tport);
289 
290 }
291 
292 /**
293  * men_z135_handle_tx() - TX tasklet routine
294  * @arg: Pointer to struct men_z135_port
295  *
296  */
297 static void men_z135_handle_tx(struct men_z135_port *uart)
298 {
299 	struct uart_port *port = &uart->port;
300 	struct circ_buf *xmit = &port->state->xmit;
301 	u32 txc;
302 	u32 wptr;
303 	int qlen;
304 	int n;
305 	int txfree;
306 	int head;
307 	int tail;
308 	int s;
309 
310 	if (uart_circ_empty(xmit))
311 		goto out;
312 
313 	if (uart_tx_stopped(port))
314 		goto out;
315 
316 	if (port->x_char)
317 		goto out;
318 
319 	/* calculate bytes to copy */
320 	qlen = uart_circ_chars_pending(xmit);
321 	if (qlen <= 0)
322 		goto out;
323 
324 	wptr = ioread32(port->membase + MEN_Z135_TX_CTRL);
325 	txc = (wptr >> 16) & 0x3ff;
326 	wptr &= 0x3ff;
327 
328 	if (txc > MEN_Z135_FIFO_WATERMARK)
329 		txc = MEN_Z135_FIFO_WATERMARK;
330 
331 	txfree = MEN_Z135_FIFO_WATERMARK - txc;
332 	if (txfree <= 0) {
333 		dev_err(&uart->mdev->dev,
334 			"Not enough room in TX FIFO have %d, need %d\n",
335 			txfree, qlen);
336 		goto irq_en;
337 	}
338 
339 	/* if we're not aligned, it's better to copy only 1 or 2 bytes and
340 	 * then the rest.
341 	 */
342 	if (align && qlen >= 3 && BYTES_TO_ALIGN(wptr))
343 		n = 4 - BYTES_TO_ALIGN(wptr);
344 	else if (qlen > txfree)
345 		n = txfree;
346 	else
347 		n = qlen;
348 
349 	if (n <= 0)
350 		goto irq_en;
351 
352 	head = xmit->head & (UART_XMIT_SIZE - 1);
353 	tail = xmit->tail & (UART_XMIT_SIZE - 1);
354 
355 	s = ((head >= tail) ? head : UART_XMIT_SIZE) - tail;
356 	n = min(n, s);
357 
358 	memcpy_toio(port->membase + MEN_Z135_TX_RAM, &xmit->buf[xmit->tail], n);
359 	xmit->tail = (xmit->tail + n) & (UART_XMIT_SIZE - 1);
360 	mmiowb();
361 
362 	iowrite32(n & 0x3ff, port->membase + MEN_Z135_TX_CTRL);
363 
364 	port->icount.tx += n;
365 
366 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
367 		uart_write_wakeup(port);
368 
369 irq_en:
370 	if (!uart_circ_empty(xmit))
371 		men_z135_reg_set(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);
372 	else
373 		men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);
374 
375 out:
376 	return;
377 
378 }
379 
380 /**
381  * men_z135_intr() - Handle legacy IRQs
382  * @irq: The IRQ number
383  * @data: Pointer to UART port
384  *
385  * Check IIR register to find the cause of the interrupt and handle it.
386  * It is possible that multiple interrupts reason bits are set and reading
387  * the IIR is a destructive read, so we always need to check for all possible
388  * interrupts and handle them.
389  */
390 static irqreturn_t men_z135_intr(int irq, void *data)
391 {
392 	struct men_z135_port *uart = (struct men_z135_port *)data;
393 	struct uart_port *port = &uart->port;
394 	bool handled = false;
395 	unsigned long flags;
396 	int irq_id;
397 
398 	uart->stat_reg = ioread32(port->membase + MEN_Z135_STAT_REG);
399 	irq_id = IRQ_ID(uart->stat_reg);
400 
401 	if (!irq_id)
402 		goto out;
403 
404 	spin_lock_irqsave(&port->lock, flags);
405 	/* It's save to write to IIR[7:6] RXC[9:8] */
406 	iowrite8(irq_id, port->membase + MEN_Z135_STAT_REG);
407 
408 	if (irq_id & MEN_Z135_IRQ_ID_RLS) {
409 		men_z135_handle_lsr(uart);
410 		handled = true;
411 	}
412 
413 	if (irq_id & (MEN_Z135_IRQ_ID_RDA | MEN_Z135_IRQ_ID_CTI)) {
414 		if (irq_id & MEN_Z135_IRQ_ID_CTI)
415 			dev_dbg(&uart->mdev->dev, "Character Timeout Indication\n");
416 		men_z135_handle_rx(uart);
417 		handled = true;
418 	}
419 
420 	if (irq_id & MEN_Z135_IRQ_ID_TSA) {
421 		men_z135_handle_tx(uart);
422 		handled = true;
423 	}
424 
425 	if (irq_id & MEN_Z135_IRQ_ID_MST) {
426 		men_z135_handle_modem_status(uart);
427 		handled = true;
428 	}
429 
430 	spin_unlock_irqrestore(&port->lock, flags);
431 out:
432 	return IRQ_RETVAL(handled);
433 }
434 
435 /**
436  * men_z135_request_irq() - Request IRQ for 16z135 core
437  * @uart: z135 private uart port structure
438  *
439  * Request an IRQ for 16z135 to use. First try using MSI, if it fails
440  * fall back to using legacy interrupts.
441  */
442 static int men_z135_request_irq(struct men_z135_port *uart)
443 {
444 	struct device *dev = &uart->mdev->dev;
445 	struct uart_port *port = &uart->port;
446 	int err = 0;
447 
448 	err = request_irq(port->irq, men_z135_intr, IRQF_SHARED,
449 			"men_z135_intr", uart);
450 	if (err)
451 		dev_err(dev, "Error %d getting interrupt\n", err);
452 
453 	return err;
454 }
455 
456 /**
457  * men_z135_tx_empty() - Handle tx_empty call
458  * @port: The UART port
459  *
460  * This function tests whether the TX FIFO and shifter for the port
461  * described by @port is empty.
462  */
463 static unsigned int men_z135_tx_empty(struct uart_port *port)
464 {
465 	u32 wptr;
466 	u16 txc;
467 
468 	wptr = ioread32(port->membase + MEN_Z135_TX_CTRL);
469 	txc = (wptr >> 16) & 0x3ff;
470 
471 	if (txc == 0)
472 		return TIOCSER_TEMT;
473 	else
474 		return 0;
475 }
476 
477 /**
478  * men_z135_set_mctrl() - Set modem control lines
479  * @port: The UART port
480  * @mctrl: The modem control lines
481  *
482  * This function sets the modem control lines for a port described by @port
483  * to the state described by @mctrl
484  */
485 static void men_z135_set_mctrl(struct uart_port *port, unsigned int mctrl)
486 {
487 	u32 old;
488 	u32 conf_reg;
489 
490 	conf_reg = old = ioread32(port->membase + MEN_Z135_CONF_REG);
491 	if (mctrl & TIOCM_RTS)
492 		conf_reg |= MEN_Z135_MCR_RTS;
493 	else
494 		conf_reg &= ~MEN_Z135_MCR_RTS;
495 
496 	if (mctrl & TIOCM_DTR)
497 		conf_reg |= MEN_Z135_MCR_DTR;
498 	else
499 		conf_reg &= ~MEN_Z135_MCR_DTR;
500 
501 	if (mctrl & TIOCM_OUT1)
502 		conf_reg |= MEN_Z135_MCR_OUT1;
503 	else
504 		conf_reg &= ~MEN_Z135_MCR_OUT1;
505 
506 	if (mctrl & TIOCM_OUT2)
507 		conf_reg |= MEN_Z135_MCR_OUT2;
508 	else
509 		conf_reg &= ~MEN_Z135_MCR_OUT2;
510 
511 	if (mctrl & TIOCM_LOOP)
512 		conf_reg |= MEN_Z135_MCR_LOOP;
513 	else
514 		conf_reg &= ~MEN_Z135_MCR_LOOP;
515 
516 	if (conf_reg != old)
517 		iowrite32(conf_reg, port->membase + MEN_Z135_CONF_REG);
518 }
519 
520 /**
521  * men_z135_get_mctrl() - Get modem control lines
522  * @port: The UART port
523  *
524  * Retruns the current state of modem control inputs.
525  */
526 static unsigned int men_z135_get_mctrl(struct uart_port *port)
527 {
528 	unsigned int mctrl = 0;
529 	u8 msr;
530 
531 	msr = ioread8(port->membase + MEN_Z135_STAT_REG + 1);
532 
533 	if (msr & MEN_Z135_MSR_CTS)
534 		mctrl |= TIOCM_CTS;
535 	if (msr & MEN_Z135_MSR_DSR)
536 		mctrl |= TIOCM_DSR;
537 	if (msr & MEN_Z135_MSR_RI)
538 		mctrl |= TIOCM_RI;
539 	if (msr & MEN_Z135_MSR_DCD)
540 		mctrl |= TIOCM_CAR;
541 
542 	return mctrl;
543 }
544 
545 /**
546  * men_z135_stop_tx() - Stop transmitting characters
547  * @port: The UART port
548  *
549  * Stop transmitting characters. This might be due to CTS line becomming
550  * inactive or the tty layer indicating we want to stop transmission due to
551  * an XOFF character.
552  */
553 static void men_z135_stop_tx(struct uart_port *port)
554 {
555 	struct men_z135_port *uart = to_men_z135(port);
556 
557 	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);
558 }
559 
560 /*
561  * men_z135_disable_ms() - Disable Modem Status
562  * port: The UART port
563  *
564  * Enable Modem Status IRQ.
565  */
566 static void men_z135_disable_ms(struct uart_port *port)
567 {
568 	struct men_z135_port *uart = to_men_z135(port);
569 
570 	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_MSIEN);
571 }
572 
573 /**
574  * men_z135_start_tx() - Start transmitting characters
575  * @port: The UART port
576  *
577  * Start transmitting character. This actually doesn't transmit anything, but
578  * fires off the TX tasklet.
579  */
580 static void men_z135_start_tx(struct uart_port *port)
581 {
582 	struct men_z135_port *uart = to_men_z135(port);
583 
584 	if (uart->automode)
585 		men_z135_disable_ms(port);
586 
587 	men_z135_handle_tx(uart);
588 }
589 
590 /**
591  * men_z135_stop_rx() - Stop receiving characters
592  * @port: The UART port
593  *
594  * Stop receiving characters; the port is in the process of being closed.
595  */
596 static void men_z135_stop_rx(struct uart_port *port)
597 {
598 	struct men_z135_port *uart = to_men_z135(port);
599 
600 	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_RXCIEN);
601 }
602 
603 /**
604  * men_z135_enable_ms() - Enable Modem Status
605  * port:
606  *
607  * Enable Modem Status IRQ.
608  */
609 static void men_z135_enable_ms(struct uart_port *port)
610 {
611 	struct men_z135_port *uart = to_men_z135(port);
612 
613 	men_z135_reg_set(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_MSIEN);
614 }
615 
616 static int men_z135_startup(struct uart_port *port)
617 {
618 	struct men_z135_port *uart = to_men_z135(port);
619 	int err;
620 	u32 conf_reg = 0;
621 
622 	err = men_z135_request_irq(uart);
623 	if (err)
624 		return -ENODEV;
625 
626 	conf_reg = ioread32(port->membase + MEN_Z135_CONF_REG);
627 
628 	/* Activate all but TX space available IRQ */
629 	conf_reg |= MEN_Z135_ALL_IRQS & ~MEN_Z135_IER_TXCIEN;
630 	conf_reg &= ~(0xff << 16);
631 	conf_reg |= (txlvl << 16);
632 	conf_reg |= (rxlvl << 20);
633 
634 	iowrite32(conf_reg, port->membase + MEN_Z135_CONF_REG);
635 
636 	if (rx_timeout)
637 		iowrite32(rx_timeout, port->membase + MEN_Z135_TIMEOUT);
638 
639 	return 0;
640 }
641 
642 static void men_z135_shutdown(struct uart_port *port)
643 {
644 	struct men_z135_port *uart = to_men_z135(port);
645 	u32 conf_reg = 0;
646 
647 	conf_reg |= MEN_Z135_ALL_IRQS;
648 
649 	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, conf_reg);
650 
651 	free_irq(uart->port.irq, uart);
652 }
653 
654 static void men_z135_set_termios(struct uart_port *port,
655 				struct ktermios *termios,
656 				struct ktermios *old)
657 {
658 	struct men_z135_port *uart = to_men_z135(port);
659 	unsigned int baud;
660 	u32 conf_reg;
661 	u32 bd_reg;
662 	u32 uart_freq;
663 	u8 lcr;
664 
665 	conf_reg = ioread32(port->membase + MEN_Z135_CONF_REG);
666 	lcr = LCR(conf_reg);
667 
668 	/* byte size */
669 	switch (termios->c_cflag & CSIZE) {
670 	case CS5:
671 		lcr |= MEN_Z135_WL5;
672 		break;
673 	case CS6:
674 		lcr |= MEN_Z135_WL6;
675 		break;
676 	case CS7:
677 		lcr |= MEN_Z135_WL7;
678 		break;
679 	case CS8:
680 		lcr |= MEN_Z135_WL8;
681 		break;
682 	}
683 
684 	/* stop bits */
685 	if (termios->c_cflag & CSTOPB)
686 		lcr |= MEN_Z135_NSTB2 << MEN_Z135_STB_SHIFT;
687 
688 	/* parity */
689 	if (termios->c_cflag & PARENB) {
690 		lcr |= MEN_Z135_PAR_ENA << MEN_Z135_PEN_SHIFT;
691 
692 		if (termios->c_cflag & PARODD)
693 			lcr |= MEN_Z135_PTY_ODD << MEN_Z135_PTY_SHIFT;
694 		else
695 			lcr |= MEN_Z135_PTY_EVN << MEN_Z135_PTY_SHIFT;
696 	} else
697 		lcr |= MEN_Z135_PAR_DIS << MEN_Z135_PEN_SHIFT;
698 
699 	conf_reg |= MEN_Z135_IER_MSIEN;
700 	if (termios->c_cflag & CRTSCTS) {
701 		conf_reg |= MEN_Z135_MCR_RCFC;
702 		uart->automode = true;
703 		termios->c_cflag &= ~CLOCAL;
704 	} else {
705 		conf_reg &= ~MEN_Z135_MCR_RCFC;
706 		uart->automode = false;
707 	}
708 
709 	termios->c_cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
710 
711 	conf_reg |= lcr << MEN_Z135_LCR_SHIFT;
712 	iowrite32(conf_reg, port->membase + MEN_Z135_CONF_REG);
713 
714 	uart_freq = ioread32(port->membase + MEN_Z135_UART_FREQ);
715 	if (uart_freq == 0)
716 		uart_freq = MEN_Z135_BASECLK;
717 
718 	baud = uart_get_baud_rate(port, termios, old, 0, uart_freq / 16);
719 
720 	spin_lock(&port->lock);
721 	if (tty_termios_baud_rate(termios))
722 		tty_termios_encode_baud_rate(termios, baud, baud);
723 
724 	bd_reg = uart_freq / (4 * baud);
725 	iowrite32(bd_reg, port->membase + MEN_Z135_BAUD_REG);
726 
727 	uart_update_timeout(port, termios->c_cflag, baud);
728 	spin_unlock(&port->lock);
729 }
730 
731 static const char *men_z135_type(struct uart_port *port)
732 {
733 	return KBUILD_MODNAME;
734 }
735 
736 static void men_z135_release_port(struct uart_port *port)
737 {
738 	iounmap(port->membase);
739 	port->membase = NULL;
740 
741 	release_mem_region(port->mapbase, MEN_Z135_MEM_SIZE);
742 }
743 
744 static int men_z135_request_port(struct uart_port *port)
745 {
746 	int size = MEN_Z135_MEM_SIZE;
747 
748 	if (!request_mem_region(port->mapbase, size, "men_z135_port"))
749 		return -EBUSY;
750 
751 	port->membase = ioremap(port->mapbase, MEN_Z135_MEM_SIZE);
752 	if (port->membase == NULL) {
753 		release_mem_region(port->mapbase, MEN_Z135_MEM_SIZE);
754 		return -ENOMEM;
755 	}
756 
757 	return 0;
758 }
759 
760 static void men_z135_config_port(struct uart_port *port, int type)
761 {
762 	port->type = PORT_MEN_Z135;
763 	men_z135_request_port(port);
764 }
765 
766 static int men_z135_verify_port(struct uart_port *port,
767 				struct serial_struct *serinfo)
768 {
769 	return -EINVAL;
770 }
771 
772 static struct uart_ops men_z135_ops = {
773 	.tx_empty = men_z135_tx_empty,
774 	.set_mctrl = men_z135_set_mctrl,
775 	.get_mctrl = men_z135_get_mctrl,
776 	.stop_tx = men_z135_stop_tx,
777 	.start_tx = men_z135_start_tx,
778 	.stop_rx = men_z135_stop_rx,
779 	.enable_ms = men_z135_enable_ms,
780 	.startup = men_z135_startup,
781 	.shutdown = men_z135_shutdown,
782 	.set_termios = men_z135_set_termios,
783 	.type = men_z135_type,
784 	.release_port = men_z135_release_port,
785 	.request_port = men_z135_request_port,
786 	.config_port = men_z135_config_port,
787 	.verify_port = men_z135_verify_port,
788 };
789 
790 static struct uart_driver men_z135_driver = {
791 	.owner = THIS_MODULE,
792 	.driver_name = KBUILD_MODNAME,
793 	.dev_name = "ttyHSU",
794 	.major = 0,
795 	.minor = 0,
796 	.nr = MEN_Z135_MAX_PORTS,
797 };
798 
799 /**
800  * men_z135_probe() - Probe a z135 instance
801  * @mdev: The MCB device
802  * @id: The MCB device ID
803  *
804  * men_z135_probe does the basic setup of hardware resources and registers the
805  * new uart port to the tty layer.
806  */
807 static int men_z135_probe(struct mcb_device *mdev,
808 			const struct mcb_device_id *id)
809 {
810 	struct men_z135_port *uart;
811 	struct resource *mem;
812 	struct device *dev;
813 	int err;
814 
815 	dev = &mdev->dev;
816 
817 	uart = devm_kzalloc(dev, sizeof(struct men_z135_port), GFP_KERNEL);
818 	if (!uart)
819 		return -ENOMEM;
820 
821 	uart->rxbuf = (unsigned char *)__get_free_page(GFP_KERNEL);
822 	if (!uart->rxbuf)
823 		return -ENOMEM;
824 
825 	mem = &mdev->mem;
826 
827 	mcb_set_drvdata(mdev, uart);
828 
829 	uart->port.uartclk = MEN_Z135_BASECLK * 16;
830 	uart->port.fifosize = MEN_Z135_FIFO_SIZE;
831 	uart->port.iotype = UPIO_MEM;
832 	uart->port.ops = &men_z135_ops;
833 	uart->port.irq = mcb_get_irq(mdev);
834 	uart->port.iotype = UPIO_MEM;
835 	uart->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
836 	uart->port.line = line++;
837 	uart->port.dev = dev;
838 	uart->port.type = PORT_MEN_Z135;
839 	uart->port.mapbase = mem->start;
840 	uart->port.membase = NULL;
841 	uart->mdev = mdev;
842 
843 	spin_lock_init(&uart->port.lock);
844 	spin_lock_init(&uart->lock);
845 
846 	err = uart_add_one_port(&men_z135_driver, &uart->port);
847 	if (err)
848 		goto err;
849 
850 	return 0;
851 
852 err:
853 	free_page((unsigned long) uart->rxbuf);
854 	dev_err(dev, "Failed to add UART: %d\n", err);
855 
856 	return err;
857 }
858 
859 /**
860  * men_z135_remove() - Remove a z135 instance from the system
861  *
862  * @mdev: The MCB device
863  */
864 static void men_z135_remove(struct mcb_device *mdev)
865 {
866 	struct men_z135_port *uart = mcb_get_drvdata(mdev);
867 
868 	line--;
869 	uart_remove_one_port(&men_z135_driver, &uart->port);
870 	free_page((unsigned long) uart->rxbuf);
871 }
872 
873 static const struct mcb_device_id men_z135_ids[] = {
874 	{ .device = 0x87 },
875 	{ }
876 };
877 MODULE_DEVICE_TABLE(mcb, men_z135_ids);
878 
879 static struct mcb_driver mcb_driver = {
880 	.driver = {
881 		.name = "z135-uart",
882 		.owner = THIS_MODULE,
883 	},
884 	.probe = men_z135_probe,
885 	.remove = men_z135_remove,
886 	.id_table = men_z135_ids,
887 };
888 
889 /**
890  * men_z135_init() - Driver Registration Routine
891  *
892  * men_z135_init is the first routine called when the driver is loaded. All it
893  * does is register with the legacy MEN Chameleon subsystem.
894  */
895 static int __init men_z135_init(void)
896 {
897 	int err;
898 
899 	err = uart_register_driver(&men_z135_driver);
900 	if (err) {
901 		pr_err("Failed to register UART: %d\n", err);
902 		return err;
903 	}
904 
905 	err = mcb_register_driver(&mcb_driver);
906 	if  (err) {
907 		pr_err("Failed to register MCB driver: %d\n", err);
908 		uart_unregister_driver(&men_z135_driver);
909 		return err;
910 	}
911 
912 	return 0;
913 }
914 module_init(men_z135_init);
915 
916 /**
917  * men_z135_exit() - Driver Exit Routine
918  *
919  * men_z135_exit is called just before the driver is removed from memory.
920  */
921 static void __exit men_z135_exit(void)
922 {
923 	mcb_unregister_driver(&mcb_driver);
924 	uart_unregister_driver(&men_z135_driver);
925 }
926 module_exit(men_z135_exit);
927 
928 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
929 MODULE_LICENSE("GPL v2");
930 MODULE_DESCRIPTION("MEN 16z135 High Speed UART");
931 MODULE_ALIAS("mcb:16z135");
932