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_NUM_MSI_VECTORS	2
27 #define MEN_Z135_FIFO_WATERMARK		1020
28 
29 #define MEN_Z135_STAT_REG		0x0
30 #define MEN_Z135_RX_RAM			0x4
31 #define MEN_Z135_TX_RAM			0x400
32 #define MEN_Z135_RX_CTRL		0x800
33 #define MEN_Z135_TX_CTRL		0x804
34 #define MEN_Z135_CONF_REG		0x808
35 #define MEN_Z135_UART_FREQ		0x80c
36 #define MEN_Z135_BAUD_REG		0x810
37 #define MENZ135_TIMEOUT			0x814
38 
39 #define MEN_Z135_MEM_SIZE		0x818
40 
41 #define IS_IRQ(x) ((x) & 1)
42 #define IRQ_ID(x) (((x) >> 1) & 7)
43 
44 #define MEN_Z135_IER_RXCIEN BIT(0)		/* RX Space IRQ */
45 #define MEN_Z135_IER_TXCIEN BIT(1)		/* TX Space IRQ */
46 #define MEN_Z135_IER_RLSIEN BIT(2)		/* Receiver Line Status IRQ */
47 #define MEN_Z135_IER_MSIEN  BIT(3)		/* Modem Status IRQ */
48 #define MEN_Z135_ALL_IRQS (MEN_Z135_IER_RXCIEN		\
49 				| MEN_Z135_IER_RLSIEN	\
50 				| MEN_Z135_IER_MSIEN	\
51 				| MEN_Z135_IER_TXCIEN)
52 
53 #define MEN_Z135_MCR_DTR	BIT(24)
54 #define MEN_Z135_MCR_RTS	BIT(25)
55 #define MEN_Z135_MCR_OUT1	BIT(26)
56 #define MEN_Z135_MCR_OUT2	BIT(27)
57 #define MEN_Z135_MCR_LOOP	BIT(28)
58 #define MEN_Z135_MCR_RCFC	BIT(29)
59 
60 #define MEN_Z135_MSR_DCTS	BIT(0)
61 #define MEN_Z135_MSR_DDSR	BIT(1)
62 #define MEN_Z135_MSR_DRI	BIT(2)
63 #define MEN_Z135_MSR_DDCD	BIT(3)
64 #define MEN_Z135_MSR_CTS	BIT(4)
65 #define MEN_Z135_MSR_DSR	BIT(5)
66 #define MEN_Z135_MSR_RI		BIT(6)
67 #define MEN_Z135_MSR_DCD	BIT(7)
68 
69 #define MEN_Z135_LCR_SHIFT 8	/* LCR shift mask */
70 
71 #define MEN_Z135_WL5 0		/* CS5 */
72 #define MEN_Z135_WL6 1		/* CS6 */
73 #define MEN_Z135_WL7 2		/* CS7 */
74 #define MEN_Z135_WL8 3		/* CS8 */
75 
76 #define MEN_Z135_STB_SHIFT 2	/* Stopbits */
77 #define MEN_Z135_NSTB1 0
78 #define MEN_Z135_NSTB2 1
79 
80 #define MEN_Z135_PEN_SHIFT 3	/* Parity enable */
81 #define MEN_Z135_PAR_DIS 0
82 #define MEN_Z135_PAR_ENA 1
83 
84 #define MEN_Z135_PTY_SHIFT 4	/* Parity type */
85 #define MEN_Z135_PTY_ODD 0
86 #define MEN_Z135_PTY_EVN 1
87 
88 #define MEN_Z135_LSR_DR BIT(0)
89 #define MEN_Z135_LSR_OE BIT(1)
90 #define MEN_Z135_LSR_PE BIT(2)
91 #define MEN_Z135_LSR_FE BIT(3)
92 #define MEN_Z135_LSR_BI BIT(4)
93 #define MEN_Z135_LSR_THEP BIT(5)
94 #define MEN_Z135_LSR_TEXP BIT(6)
95 #define MEN_Z135_LSR_RXFIFOERR BIT(7)
96 
97 #define MEN_Z135_IRQ_ID_MST 0
98 #define MEN_Z135_IRQ_ID_TSA 1
99 #define MEN_Z135_IRQ_ID_RDA 2
100 #define MEN_Z135_IRQ_ID_RLS 3
101 #define MEN_Z135_IRQ_ID_CTI 6
102 
103 #define LCR(x) (((x) >> MEN_Z135_LCR_SHIFT) & 0xff)
104 
105 #define BYTES_TO_ALIGN(x) ((x) & 0x3)
106 
107 static int line;
108 
109 static int txlvl = 5;
110 module_param(txlvl, int, S_IRUGO);
111 MODULE_PARM_DESC(txlvl, "TX IRQ trigger level 0-7, default 5 (128 byte)");
112 
113 static int rxlvl = 6;
114 module_param(rxlvl, int, S_IRUGO);
115 MODULE_PARM_DESC(rxlvl, "RX IRQ trigger level 0-7, default 6 (256 byte)");
116 
117 static int align;
118 module_param(align, int, S_IRUGO);
119 MODULE_PARM_DESC(align, "Keep hardware FIFO write pointer aligned, default 0");
120 
121 struct men_z135_port {
122 	struct uart_port port;
123 	struct mcb_device *mdev;
124 	unsigned char *rxbuf;
125 	u32 stat_reg;
126 	spinlock_t lock;
127 };
128 #define to_men_z135(port) container_of((port), struct men_z135_port, port)
129 
130 /**
131  * men_z135_reg_set() - Set value in register
132  * @uart: The UART port
133  * @addr: Register address
134  * @val: value to set
135  */
136 static inline void men_z135_reg_set(struct men_z135_port *uart,
137 				u32 addr, u32 val)
138 {
139 	struct uart_port *port = &uart->port;
140 	unsigned long flags;
141 	u32 reg;
142 
143 	spin_lock_irqsave(&uart->lock, flags);
144 
145 	reg = ioread32(port->membase + addr);
146 	reg |= val;
147 	iowrite32(reg, port->membase + addr);
148 
149 	spin_unlock_irqrestore(&uart->lock, flags);
150 }
151 
152 /**
153  * men_z135_reg_clr() - Unset value in register
154  * @uart: The UART port
155  * @addr: Register address
156  * @val: value to clear
157  */
158 static inline void men_z135_reg_clr(struct men_z135_port *uart,
159 				u32 addr, u32 val)
160 {
161 	struct uart_port *port = &uart->port;
162 	unsigned long flags;
163 	u32 reg;
164 
165 	spin_lock_irqsave(&uart->lock, flags);
166 
167 	reg = ioread32(port->membase + addr);
168 	reg &= ~val;
169 	iowrite32(reg, port->membase + addr);
170 
171 	spin_unlock_irqrestore(&uart->lock, flags);
172 }
173 
174 /**
175  * men_z135_handle_modem_status() - Handle change of modem status
176  * @port: The UART port
177  *
178  * Handle change of modem status register. This is done by reading the "delta"
179  * versions of DCD (Data Carrier Detect) and CTS (Clear To Send).
180  */
181 static void men_z135_handle_modem_status(struct men_z135_port *uart)
182 {
183 	if (uart->stat_reg & MEN_Z135_MSR_DDCD)
184 		uart_handle_dcd_change(&uart->port,
185 				uart->stat_reg & ~MEN_Z135_MSR_DCD);
186 	if (uart->stat_reg & MEN_Z135_MSR_DCTS)
187 		uart_handle_cts_change(&uart->port,
188 				uart->stat_reg & ~MEN_Z135_MSR_CTS);
189 }
190 
191 static void men_z135_handle_lsr(struct men_z135_port *uart)
192 {
193 	struct uart_port *port = &uart->port;
194 	u8 lsr;
195 
196 	lsr = (uart->stat_reg >> 16) & 0xff;
197 
198 	if (lsr & MEN_Z135_LSR_OE)
199 		port->icount.overrun++;
200 	if (lsr & MEN_Z135_LSR_PE)
201 		port->icount.parity++;
202 	if (lsr & MEN_Z135_LSR_FE)
203 		port->icount.frame++;
204 	if (lsr & MEN_Z135_LSR_BI) {
205 		port->icount.brk++;
206 		uart_handle_break(port);
207 	}
208 }
209 
210 /**
211  * get_rx_fifo_content() - Get the number of bytes in RX FIFO
212  * @uart: The UART port
213  *
214  * Read RXC register from hardware and return current FIFO fill size.
215  */
216 static u16 get_rx_fifo_content(struct men_z135_port *uart)
217 {
218 	struct uart_port *port = &uart->port;
219 	u32 stat_reg;
220 	u16 rxc;
221 	u8 rxc_lo;
222 	u8 rxc_hi;
223 
224 	stat_reg = ioread32(port->membase + MEN_Z135_STAT_REG);
225 	rxc_lo = stat_reg >> 24;
226 	rxc_hi = (stat_reg & 0xC0) >> 6;
227 
228 	rxc = rxc_lo | (rxc_hi << 8);
229 
230 	return rxc;
231 }
232 
233 /**
234  * men_z135_handle_rx() - RX tasklet routine
235  * @arg: Pointer to struct men_z135_port
236  *
237  * Copy from RX FIFO and acknowledge number of bytes copied.
238  */
239 static void men_z135_handle_rx(struct men_z135_port *uart)
240 {
241 	struct uart_port *port = &uart->port;
242 	struct tty_port *tport = &port->state->port;
243 	int copied;
244 	u16 size;
245 	int room;
246 
247 	size = get_rx_fifo_content(uart);
248 
249 	if (size == 0)
250 		return;
251 
252 	/* Avoid accidently accessing TX FIFO instead of RX FIFO. Last
253 	 * longword in RX FIFO cannot be read.(0x004-0x3FF)
254 	 */
255 	if (size > MEN_Z135_FIFO_WATERMARK)
256 		size = MEN_Z135_FIFO_WATERMARK;
257 
258 	room = tty_buffer_request_room(tport, size);
259 	if (room != size)
260 		dev_warn(&uart->mdev->dev,
261 			"Not enough room in flip buffer, truncating to %d\n",
262 			room);
263 
264 	if (room == 0)
265 		return;
266 
267 	memcpy_fromio(uart->rxbuf, port->membase + MEN_Z135_RX_RAM, room);
268 	/* Be sure to first copy all data and then acknowledge it */
269 	mb();
270 	iowrite32(room, port->membase +  MEN_Z135_RX_CTRL);
271 
272 	copied = tty_insert_flip_string(tport, uart->rxbuf, room);
273 	if (copied != room)
274 		dev_warn(&uart->mdev->dev,
275 			"Only copied %d instead of %d bytes\n",
276 			copied, room);
277 
278 	port->icount.rx += copied;
279 
280 	tty_flip_buffer_push(tport);
281 
282 }
283 
284 /**
285  * men_z135_handle_tx() - TX tasklet routine
286  * @arg: Pointer to struct men_z135_port
287  *
288  */
289 static void men_z135_handle_tx(struct men_z135_port *uart)
290 {
291 	struct uart_port *port = &uart->port;
292 	struct circ_buf *xmit = &port->state->xmit;
293 	u32 txc;
294 	u32 wptr;
295 	int qlen;
296 	int n;
297 	int txfree;
298 	int head;
299 	int tail;
300 	int s;
301 
302 	if (uart_circ_empty(xmit))
303 		goto out;
304 
305 	if (uart_tx_stopped(port))
306 		goto out;
307 
308 	if (port->x_char)
309 		goto out;
310 
311 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
312 		uart_write_wakeup(port);
313 
314 	/* calculate bytes to copy */
315 	qlen = uart_circ_chars_pending(xmit);
316 	if (qlen <= 0)
317 		goto out;
318 
319 	wptr = ioread32(port->membase + MEN_Z135_TX_CTRL);
320 	txc = (wptr >> 16) & 0x3ff;
321 	wptr &= 0x3ff;
322 
323 	if (txc > MEN_Z135_FIFO_WATERMARK)
324 		txc = MEN_Z135_FIFO_WATERMARK;
325 
326 	txfree = MEN_Z135_FIFO_WATERMARK - txc;
327 	if (txfree <= 0) {
328 		pr_err("Not enough room in TX FIFO have %d, need %d\n",
329 			txfree, qlen);
330 		goto irq_en;
331 	}
332 
333 	/* if we're not aligned, it's better to copy only 1 or 2 bytes and
334 	 * then the rest.
335 	 */
336 	if (align && qlen >= 3 && BYTES_TO_ALIGN(wptr))
337 		n = 4 - BYTES_TO_ALIGN(wptr);
338 	else if (qlen > txfree)
339 		n = txfree;
340 	else
341 		n = qlen;
342 
343 	if (n <= 0)
344 		goto irq_en;
345 
346 	head = xmit->head & (UART_XMIT_SIZE - 1);
347 	tail = xmit->tail & (UART_XMIT_SIZE - 1);
348 
349 	s = ((head >= tail) ? head : UART_XMIT_SIZE) - tail;
350 	n = min(n, s);
351 
352 	memcpy_toio(port->membase + MEN_Z135_TX_RAM, &xmit->buf[xmit->tail], n);
353 	xmit->tail = (xmit->tail + n) & (UART_XMIT_SIZE - 1);
354 	mmiowb();
355 
356 	iowrite32(n & 0x3ff, port->membase + MEN_Z135_TX_CTRL);
357 
358 	port->icount.tx += n;
359 
360 irq_en:
361 	if (!uart_circ_empty(xmit))
362 		men_z135_reg_set(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);
363 	else
364 		men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);
365 
366 out:
367 	return;
368 
369 }
370 
371 /**
372  * men_z135_intr() - Handle legacy IRQs
373  * @irq: The IRQ number
374  * @data: Pointer to UART port
375  *
376  * Check IIR register to see which tasklet to start.
377  */
378 static irqreturn_t men_z135_intr(int irq, void *data)
379 {
380 	struct men_z135_port *uart = (struct men_z135_port *)data;
381 	struct uart_port *port = &uart->port;
382 	int irq_id;
383 
384 	uart->stat_reg = ioread32(port->membase + MEN_Z135_STAT_REG);
385 	/* IRQ pending is low active */
386 	if (IS_IRQ(uart->stat_reg))
387 		return IRQ_NONE;
388 
389 	irq_id = IRQ_ID(uart->stat_reg);
390 	switch (irq_id) {
391 	case MEN_Z135_IRQ_ID_MST:
392 		men_z135_handle_modem_status(uart);
393 		break;
394 	case MEN_Z135_IRQ_ID_TSA:
395 		men_z135_handle_tx(uart);
396 		break;
397 	case MEN_Z135_IRQ_ID_CTI:
398 		dev_dbg(&uart->mdev->dev, "Character Timeout Indication\n");
399 		/* Fallthrough */
400 	case MEN_Z135_IRQ_ID_RDA:
401 		/* Reading data clears RX IRQ */
402 		men_z135_handle_rx(uart);
403 		break;
404 	case MEN_Z135_IRQ_ID_RLS:
405 		men_z135_handle_lsr(uart);
406 		break;
407 	default:
408 		dev_warn(&uart->mdev->dev, "Unknown IRQ id %d\n", irq_id);
409 		return IRQ_NONE;
410 	}
411 
412 	return IRQ_HANDLED;
413 }
414 
415 /**
416  * men_z135_request_irq() - Request IRQ for 16z135 core
417  * @uart: z135 private uart port structure
418  *
419  * Request an IRQ for 16z135 to use. First try using MSI, if it fails
420  * fall back to using legacy interrupts.
421  */
422 static int men_z135_request_irq(struct men_z135_port *uart)
423 {
424 	struct device *dev = &uart->mdev->dev;
425 	struct uart_port *port = &uart->port;
426 	int err = 0;
427 
428 	err = request_irq(port->irq, men_z135_intr, IRQF_SHARED,
429 			"men_z135_intr", uart);
430 	if (err)
431 		dev_err(dev, "Error %d getting interrupt\n", err);
432 
433 	return err;
434 }
435 
436 /**
437  * men_z135_tx_empty() - Handle tx_empty call
438  * @port: The UART port
439  *
440  * This function tests whether the TX FIFO and shifter for the port
441  * described by @port is empty.
442  */
443 static unsigned int men_z135_tx_empty(struct uart_port *port)
444 {
445 	u32 wptr;
446 	u16 txc;
447 
448 	wptr = ioread32(port->membase + MEN_Z135_TX_CTRL);
449 	txc = (wptr >> 16) & 0x3ff;
450 
451 	if (txc == 0)
452 		return TIOCSER_TEMT;
453 	else
454 		return 0;
455 }
456 
457 /**
458  * men_z135_set_mctrl() - Set modem control lines
459  * @port: The UART port
460  * @mctrl: The modem control lines
461  *
462  * This function sets the modem control lines for a port described by @port
463  * to the state described by @mctrl
464  */
465 static void men_z135_set_mctrl(struct uart_port *port, unsigned int mctrl)
466 {
467 	struct men_z135_port *uart = to_men_z135(port);
468 	u32 conf_reg = 0;
469 
470 	if (mctrl & TIOCM_RTS)
471 		conf_reg |= MEN_Z135_MCR_RTS;
472 	if (mctrl & TIOCM_DTR)
473 		conf_reg |= MEN_Z135_MCR_DTR;
474 	if (mctrl & TIOCM_OUT1)
475 		conf_reg |= MEN_Z135_MCR_OUT1;
476 	if (mctrl & TIOCM_OUT2)
477 		conf_reg |= MEN_Z135_MCR_OUT2;
478 	if (mctrl & TIOCM_LOOP)
479 		conf_reg |= MEN_Z135_MCR_LOOP;
480 
481 	men_z135_reg_set(uart, MEN_Z135_CONF_REG, conf_reg);
482 }
483 
484 /**
485  * men_z135_get_mctrl() - Get modem control lines
486  * @port: The UART port
487  *
488  * Retruns the current state of modem control inputs.
489  */
490 static unsigned int men_z135_get_mctrl(struct uart_port *port)
491 {
492 	unsigned int mctrl = 0;
493 	u32 stat_reg;
494 	u8 msr;
495 
496 	stat_reg = ioread32(port->membase + MEN_Z135_STAT_REG);
497 
498 	msr = ~((stat_reg >> 8) & 0xff);
499 
500 	if (msr & MEN_Z135_MSR_CTS)
501 		mctrl |= TIOCM_CTS;
502 	if (msr & MEN_Z135_MSR_DSR)
503 		mctrl |= TIOCM_DSR;
504 	if (msr & MEN_Z135_MSR_RI)
505 		mctrl |= TIOCM_RI;
506 	if (msr & MEN_Z135_MSR_DCD)
507 		mctrl |= TIOCM_CAR;
508 
509 	return mctrl;
510 }
511 
512 /**
513  * men_z135_stop_tx() - Stop transmitting characters
514  * @port: The UART port
515  *
516  * Stop transmitting characters. This might be due to CTS line becomming
517  * inactive or the tty layer indicating we want to stop transmission due to
518  * an XOFF character.
519  */
520 static void men_z135_stop_tx(struct uart_port *port)
521 {
522 	struct men_z135_port *uart = to_men_z135(port);
523 
524 	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);
525 }
526 
527 /**
528  * men_z135_start_tx() - Start transmitting characters
529  * @port: The UART port
530  *
531  * Start transmitting character. This actually doesn't transmit anything, but
532  * fires off the TX tasklet.
533  */
534 static void men_z135_start_tx(struct uart_port *port)
535 {
536 	struct men_z135_port *uart = to_men_z135(port);
537 
538 	men_z135_handle_tx(uart);
539 }
540 
541 /**
542  * men_z135_stop_rx() - Stop receiving characters
543  * @port: The UART port
544  *
545  * Stop receiving characters; the port is in the process of being closed.
546  */
547 static void men_z135_stop_rx(struct uart_port *port)
548 {
549 	struct men_z135_port *uart = to_men_z135(port);
550 
551 	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_RXCIEN);
552 }
553 
554 /**
555  * men_z135_enable_ms() - Enable Modem Status
556  * port:
557  *
558  * Enable Modem Status IRQ.
559  */
560 static void men_z135_enable_ms(struct uart_port *port)
561 {
562 	struct men_z135_port *uart = to_men_z135(port);
563 
564 	men_z135_reg_set(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_MSIEN);
565 }
566 
567 static int men_z135_startup(struct uart_port *port)
568 {
569 	struct men_z135_port *uart = to_men_z135(port);
570 	int err;
571 	u32 conf_reg = 0;
572 
573 	err = men_z135_request_irq(uart);
574 	if (err)
575 		return -ENODEV;
576 
577 	conf_reg = ioread32(port->membase + MEN_Z135_CONF_REG);
578 
579 	/* Activate all but TX space available IRQ */
580 	conf_reg |= MEN_Z135_ALL_IRQS & ~MEN_Z135_IER_TXCIEN;
581 	conf_reg &= ~(0xff << 16);
582 	conf_reg |= (txlvl << 16);
583 	conf_reg |= (rxlvl << 20);
584 
585 	iowrite32(conf_reg, port->membase + MEN_Z135_CONF_REG);
586 
587 	return 0;
588 }
589 
590 static void men_z135_shutdown(struct uart_port *port)
591 {
592 	struct men_z135_port *uart = to_men_z135(port);
593 	u32 conf_reg = 0;
594 
595 	conf_reg |= MEN_Z135_ALL_IRQS;
596 
597 	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, conf_reg);
598 
599 	free_irq(uart->port.irq, uart);
600 }
601 
602 static void men_z135_set_termios(struct uart_port *port,
603 				struct ktermios *termios,
604 				struct ktermios *old)
605 {
606 	unsigned int baud;
607 	u32 conf_reg;
608 	u32 bd_reg;
609 	u32 uart_freq;
610 	u8 lcr;
611 
612 	conf_reg = ioread32(port->membase + MEN_Z135_CONF_REG);
613 	lcr = LCR(conf_reg);
614 
615 	/* byte size */
616 	switch (termios->c_cflag & CSIZE) {
617 	case CS5:
618 		lcr |= MEN_Z135_WL5;
619 		break;
620 	case CS6:
621 		lcr |= MEN_Z135_WL6;
622 		break;
623 	case CS7:
624 		lcr |= MEN_Z135_WL7;
625 		break;
626 	case CS8:
627 		lcr |= MEN_Z135_WL8;
628 		break;
629 	}
630 
631 	/* stop bits */
632 	if (termios->c_cflag & CSTOPB)
633 		lcr |= MEN_Z135_NSTB2 << MEN_Z135_STB_SHIFT;
634 
635 	/* parity */
636 	if (termios->c_cflag & PARENB) {
637 		lcr |= MEN_Z135_PAR_ENA << MEN_Z135_PEN_SHIFT;
638 
639 		if (termios->c_cflag & PARODD)
640 			lcr |= MEN_Z135_PTY_ODD << MEN_Z135_PTY_SHIFT;
641 		else
642 			lcr |= MEN_Z135_PTY_EVN << MEN_Z135_PTY_SHIFT;
643 	} else
644 		lcr |= MEN_Z135_PAR_DIS << MEN_Z135_PEN_SHIFT;
645 
646 	termios->c_cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
647 
648 	conf_reg |= lcr << MEN_Z135_LCR_SHIFT;
649 	iowrite32(conf_reg, port->membase + MEN_Z135_CONF_REG);
650 
651 	uart_freq = ioread32(port->membase + MEN_Z135_UART_FREQ);
652 	if (uart_freq == 0)
653 		uart_freq = MEN_Z135_BASECLK;
654 
655 	baud = uart_get_baud_rate(port, termios, old, 0, uart_freq / 16);
656 
657 	spin_lock(&port->lock);
658 	if (tty_termios_baud_rate(termios))
659 		tty_termios_encode_baud_rate(termios, baud, baud);
660 
661 	bd_reg = uart_freq / (4 * baud);
662 	iowrite32(bd_reg, port->membase + MEN_Z135_BAUD_REG);
663 
664 	uart_update_timeout(port, termios->c_cflag, baud);
665 	spin_unlock(&port->lock);
666 }
667 
668 static const char *men_z135_type(struct uart_port *port)
669 {
670 	return KBUILD_MODNAME;
671 }
672 
673 static void men_z135_release_port(struct uart_port *port)
674 {
675 	iounmap(port->membase);
676 	port->membase = NULL;
677 
678 	release_mem_region(port->mapbase, MEN_Z135_MEM_SIZE);
679 }
680 
681 static int men_z135_request_port(struct uart_port *port)
682 {
683 	int size = MEN_Z135_MEM_SIZE;
684 
685 	if (!request_mem_region(port->mapbase, size, "men_z135_port"))
686 		return -EBUSY;
687 
688 	port->membase = ioremap(port->mapbase, MEN_Z135_MEM_SIZE);
689 	if (port->membase == NULL) {
690 		release_mem_region(port->mapbase, MEN_Z135_MEM_SIZE);
691 		return -ENOMEM;
692 	}
693 
694 	return 0;
695 }
696 
697 static void men_z135_config_port(struct uart_port *port, int type)
698 {
699 	port->type = PORT_MEN_Z135;
700 	men_z135_request_port(port);
701 }
702 
703 static int men_z135_verify_port(struct uart_port *port,
704 				struct serial_struct *serinfo)
705 {
706 	return -EINVAL;
707 }
708 
709 static struct uart_ops men_z135_ops = {
710 	.tx_empty = men_z135_tx_empty,
711 	.set_mctrl = men_z135_set_mctrl,
712 	.get_mctrl = men_z135_get_mctrl,
713 	.stop_tx = men_z135_stop_tx,
714 	.start_tx = men_z135_start_tx,
715 	.stop_rx = men_z135_stop_rx,
716 	.enable_ms = men_z135_enable_ms,
717 	.startup = men_z135_startup,
718 	.shutdown = men_z135_shutdown,
719 	.set_termios = men_z135_set_termios,
720 	.type = men_z135_type,
721 	.release_port = men_z135_release_port,
722 	.request_port = men_z135_request_port,
723 	.config_port = men_z135_config_port,
724 	.verify_port = men_z135_verify_port,
725 };
726 
727 static struct uart_driver men_z135_driver = {
728 	.owner = THIS_MODULE,
729 	.driver_name = KBUILD_MODNAME,
730 	.dev_name = "ttyHSU",
731 	.major = 0,
732 	.minor = 0,
733 	.nr = MEN_Z135_MAX_PORTS,
734 };
735 
736 /**
737  * men_z135_probe() - Probe a z135 instance
738  * @mdev: The MCB device
739  * @id: The MCB device ID
740  *
741  * men_z135_probe does the basic setup of hardware resources and registers the
742  * new uart port to the tty layer.
743  */
744 static int men_z135_probe(struct mcb_device *mdev,
745 			const struct mcb_device_id *id)
746 {
747 	struct men_z135_port *uart;
748 	struct resource *mem;
749 	struct device *dev;
750 	int err;
751 
752 	dev = &mdev->dev;
753 
754 	uart = devm_kzalloc(dev, sizeof(struct men_z135_port), GFP_KERNEL);
755 	if (!uart)
756 		return -ENOMEM;
757 
758 	uart->rxbuf = (unsigned char *)__get_free_page(GFP_KERNEL);
759 	if (!uart->rxbuf)
760 		return -ENOMEM;
761 
762 	mem = &mdev->mem;
763 
764 	mcb_set_drvdata(mdev, uart);
765 
766 	uart->port.uartclk = MEN_Z135_BASECLK * 16;
767 	uart->port.fifosize = MEN_Z135_FIFO_SIZE;
768 	uart->port.iotype = UPIO_MEM;
769 	uart->port.ops = &men_z135_ops;
770 	uart->port.irq = mcb_get_irq(mdev);
771 	uart->port.iotype = UPIO_MEM;
772 	uart->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
773 	uart->port.line = line++;
774 	uart->port.dev = dev;
775 	uart->port.type = PORT_MEN_Z135;
776 	uart->port.mapbase = mem->start;
777 	uart->port.membase = NULL;
778 	uart->mdev = mdev;
779 
780 	spin_lock_init(&uart->port.lock);
781 	spin_lock_init(&uart->lock);
782 
783 	err = uart_add_one_port(&men_z135_driver, &uart->port);
784 	if (err)
785 		goto err;
786 
787 	return 0;
788 
789 err:
790 	free_page((unsigned long) uart->rxbuf);
791 	dev_err(dev, "Failed to add UART: %d\n", err);
792 
793 	return err;
794 }
795 
796 /**
797  * men_z135_remove() - Remove a z135 instance from the system
798  *
799  * @mdev: The MCB device
800  */
801 static void men_z135_remove(struct mcb_device *mdev)
802 {
803 	struct men_z135_port *uart = mcb_get_drvdata(mdev);
804 
805 	line--;
806 	uart_remove_one_port(&men_z135_driver, &uart->port);
807 	free_page((unsigned long) uart->rxbuf);
808 }
809 
810 static const struct mcb_device_id men_z135_ids[] = {
811 	{ .device = 0x87 },
812 };
813 MODULE_DEVICE_TABLE(mcb, men_z135_ids);
814 
815 static struct mcb_driver mcb_driver = {
816 	.driver = {
817 		.name = "z135-uart",
818 		.owner = THIS_MODULE,
819 	},
820 	.probe = men_z135_probe,
821 	.remove = men_z135_remove,
822 	.id_table = men_z135_ids,
823 };
824 
825 /**
826  * men_z135_init() - Driver Registration Routine
827  *
828  * men_z135_init is the first routine called when the driver is loaded. All it
829  * does is register with the legacy MEN Chameleon subsystem.
830  */
831 static int __init men_z135_init(void)
832 {
833 	int err;
834 
835 	err = uart_register_driver(&men_z135_driver);
836 	if (err) {
837 		pr_err("Failed to register UART: %d\n", err);
838 		return err;
839 	}
840 
841 	err = mcb_register_driver(&mcb_driver);
842 	if  (err) {
843 		pr_err("Failed to register MCB driver: %d\n", err);
844 		uart_unregister_driver(&men_z135_driver);
845 		return err;
846 	}
847 
848 	return 0;
849 }
850 module_init(men_z135_init);
851 
852 /**
853  * men_z135_exit() - Driver Exit Routine
854  *
855  * men_z135_exit is called just before the driver is removed from memory.
856  */
857 static void __exit men_z135_exit(void)
858 {
859 	mcb_unregister_driver(&mcb_driver);
860 	uart_unregister_driver(&men_z135_driver);
861 }
862 module_exit(men_z135_exit);
863 
864 MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
865 MODULE_LICENSE("GPL v2");
866 MODULE_DESCRIPTION("MEN 16z135 High Speed UART");
867 MODULE_ALIAS("mcb:16z135");
868