xref: /openbmc/linux/drivers/usb/serial/f81232.c (revision a06c488d) 
1 /*
2  * Fintek F81232 USB to serial adaptor driver
3  *
4  * Copyright (C) 2012 Greg Kroah-Hartman (gregkh@linuxfoundation.org)
5  * Copyright (C) 2012 Linux Foundation
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 version 2 as published by
9  * the Free Software Foundation.
10  *
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/slab.h>
16 #include <linux/tty.h>
17 #include <linux/tty_driver.h>
18 #include <linux/tty_flip.h>
19 #include <linux/serial.h>
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <linux/mutex.h>
23 #include <linux/uaccess.h>
24 #include <linux/usb.h>
25 #include <linux/usb/serial.h>
26 #include <linux/serial_reg.h>
27 
28 static const struct usb_device_id id_table[] = {
29 	{ USB_DEVICE(0x1934, 0x0706) },
30 	{ }					/* Terminating entry */
31 };
32 MODULE_DEVICE_TABLE(usb, id_table);
33 
34 /* Maximum baudrate for F81232 */
35 #define F81232_MAX_BAUDRATE		115200
36 
37 /* USB Control EP parameter */
38 #define F81232_REGISTER_REQUEST		0xa0
39 #define F81232_GET_REGISTER		0xc0
40 #define F81232_SET_REGISTER		0x40
41 
42 #define SERIAL_BASE_ADDRESS		0x0120
43 #define RECEIVE_BUFFER_REGISTER		(0x00 + SERIAL_BASE_ADDRESS)
44 #define INTERRUPT_ENABLE_REGISTER	(0x01 + SERIAL_BASE_ADDRESS)
45 #define FIFO_CONTROL_REGISTER		(0x02 + SERIAL_BASE_ADDRESS)
46 #define LINE_CONTROL_REGISTER		(0x03 + SERIAL_BASE_ADDRESS)
47 #define MODEM_CONTROL_REGISTER		(0x04 + SERIAL_BASE_ADDRESS)
48 #define MODEM_STATUS_REGISTER		(0x06 + SERIAL_BASE_ADDRESS)
49 
50 struct f81232_private {
51 	struct mutex lock;
52 	u8 modem_control;
53 	u8 modem_status;
54 	struct work_struct interrupt_work;
55 	struct usb_serial_port *port;
56 };
57 
58 static int calc_baud_divisor(speed_t baudrate)
59 {
60 	return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);
61 }
62 
63 static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
64 {
65 	int status;
66 	u8 *tmp;
67 	struct usb_device *dev = port->serial->dev;
68 
69 	tmp = kmalloc(sizeof(*val), GFP_KERNEL);
70 	if (!tmp)
71 		return -ENOMEM;
72 
73 	status = usb_control_msg(dev,
74 				usb_rcvctrlpipe(dev, 0),
75 				F81232_REGISTER_REQUEST,
76 				F81232_GET_REGISTER,
77 				reg,
78 				0,
79 				tmp,
80 				sizeof(*val),
81 				USB_CTRL_GET_TIMEOUT);
82 	if (status != sizeof(*val)) {
83 		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
84 
85 		if (status < 0)
86 			status = usb_translate_errors(status);
87 		else
88 			status = -EIO;
89 	} else {
90 		status = 0;
91 		*val = *tmp;
92 	}
93 
94 	kfree(tmp);
95 	return status;
96 }
97 
98 static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val)
99 {
100 	int status;
101 	u8 *tmp;
102 	struct usb_device *dev = port->serial->dev;
103 
104 	tmp = kmalloc(sizeof(val), GFP_KERNEL);
105 	if (!tmp)
106 		return -ENOMEM;
107 
108 	*tmp = val;
109 
110 	status = usb_control_msg(dev,
111 				usb_sndctrlpipe(dev, 0),
112 				F81232_REGISTER_REQUEST,
113 				F81232_SET_REGISTER,
114 				reg,
115 				0,
116 				tmp,
117 				sizeof(val),
118 				USB_CTRL_SET_TIMEOUT);
119 	if (status != sizeof(val)) {
120 		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
121 
122 		if (status < 0)
123 			status = usb_translate_errors(status);
124 		else
125 			status = -EIO;
126 	} else {
127 		status = 0;
128 	}
129 
130 	kfree(tmp);
131 	return status;
132 }
133 
134 static void f81232_read_msr(struct usb_serial_port *port)
135 {
136 	int status;
137 	u8 current_msr;
138 	struct tty_struct *tty;
139 	struct f81232_private *priv = usb_get_serial_port_data(port);
140 
141 	mutex_lock(&priv->lock);
142 	status = f81232_get_register(port, MODEM_STATUS_REGISTER,
143 			&current_msr);
144 	if (status) {
145 		dev_err(&port->dev, "%s fail, status: %d\n", __func__, status);
146 		mutex_unlock(&priv->lock);
147 		return;
148 	}
149 
150 	if (!(current_msr & UART_MSR_ANY_DELTA)) {
151 		mutex_unlock(&priv->lock);
152 		return;
153 	}
154 
155 	priv->modem_status = current_msr;
156 
157 	if (current_msr & UART_MSR_DCTS)
158 		port->icount.cts++;
159 	if (current_msr & UART_MSR_DDSR)
160 		port->icount.dsr++;
161 	if (current_msr & UART_MSR_TERI)
162 		port->icount.rng++;
163 	if (current_msr & UART_MSR_DDCD) {
164 		port->icount.dcd++;
165 		tty = tty_port_tty_get(&port->port);
166 		if (tty) {
167 			usb_serial_handle_dcd_change(port, tty,
168 					current_msr & UART_MSR_DCD);
169 
170 			tty_kref_put(tty);
171 		}
172 	}
173 
174 	wake_up_interruptible(&port->port.delta_msr_wait);
175 	mutex_unlock(&priv->lock);
176 }
177 
178 static int f81232_set_mctrl(struct usb_serial_port *port,
179 					   unsigned int set, unsigned int clear)
180 {
181 	u8 val;
182 	int status;
183 	struct f81232_private *priv = usb_get_serial_port_data(port);
184 
185 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0)
186 		return 0;	/* no change */
187 
188 	/* 'set' takes precedence over 'clear' */
189 	clear &= ~set;
190 
191 	/* force enable interrupt with OUT2 */
192 	mutex_lock(&priv->lock);
193 	val = UART_MCR_OUT2 | priv->modem_control;
194 
195 	if (clear & TIOCM_DTR)
196 		val &= ~UART_MCR_DTR;
197 
198 	if (clear & TIOCM_RTS)
199 		val &= ~UART_MCR_RTS;
200 
201 	if (set & TIOCM_DTR)
202 		val |= UART_MCR_DTR;
203 
204 	if (set & TIOCM_RTS)
205 		val |= UART_MCR_RTS;
206 
207 	dev_dbg(&port->dev, "%s new:%02x old:%02x\n", __func__,
208 			val, priv->modem_control);
209 
210 	status = f81232_set_register(port, MODEM_CONTROL_REGISTER, val);
211 	if (status) {
212 		dev_err(&port->dev, "%s set MCR status < 0\n", __func__);
213 		mutex_unlock(&priv->lock);
214 		return status;
215 	}
216 
217 	priv->modem_control = val;
218 	mutex_unlock(&priv->lock);
219 
220 	return 0;
221 }
222 
223 static void f81232_update_line_status(struct usb_serial_port *port,
224 				      unsigned char *data,
225 				      size_t actual_length)
226 {
227 	struct f81232_private *priv = usb_get_serial_port_data(port);
228 
229 	if (!actual_length)
230 		return;
231 
232 	switch (data[0] & 0x07) {
233 	case 0x00: /* msr change */
234 		dev_dbg(&port->dev, "IIR: MSR Change: %02x\n", data[0]);
235 		schedule_work(&priv->interrupt_work);
236 		break;
237 	case 0x02: /* tx-empty */
238 		break;
239 	case 0x04: /* rx data available */
240 		break;
241 	case 0x06: /* lsr change */
242 		/* we can forget it. the LSR will read from bulk-in */
243 		dev_dbg(&port->dev, "IIR: LSR Change: %02x\n", data[0]);
244 		break;
245 	}
246 }
247 
248 static void f81232_read_int_callback(struct urb *urb)
249 {
250 	struct usb_serial_port *port =  urb->context;
251 	unsigned char *data = urb->transfer_buffer;
252 	unsigned int actual_length = urb->actual_length;
253 	int status = urb->status;
254 	int retval;
255 
256 	switch (status) {
257 	case 0:
258 		/* success */
259 		break;
260 	case -ECONNRESET:
261 	case -ENOENT:
262 	case -ESHUTDOWN:
263 		/* this urb is terminated, clean up */
264 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
265 			__func__, status);
266 		return;
267 	default:
268 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
269 			__func__, status);
270 		goto exit;
271 	}
272 
273 	usb_serial_debug_data(&port->dev, __func__,
274 			      urb->actual_length, urb->transfer_buffer);
275 
276 	f81232_update_line_status(port, data, actual_length);
277 
278 exit:
279 	retval = usb_submit_urb(urb, GFP_ATOMIC);
280 	if (retval)
281 		dev_err(&urb->dev->dev,
282 			"%s - usb_submit_urb failed with result %d\n",
283 			__func__, retval);
284 }
285 
286 static void f81232_process_read_urb(struct urb *urb)
287 {
288 	struct usb_serial_port *port = urb->context;
289 	unsigned char *data = urb->transfer_buffer;
290 	char tty_flag;
291 	unsigned int i;
292 	u8 lsr;
293 
294 	/*
295 	 * When opening the port we get a 1-byte packet with the current LSR,
296 	 * which we discard.
297 	 */
298 	if ((urb->actual_length < 2) || (urb->actual_length % 2))
299 		return;
300 
301 	/* bulk-in data: [LSR(1Byte)+DATA(1Byte)][LSR(1Byte)+DATA(1Byte)]... */
302 
303 	for (i = 0; i < urb->actual_length; i += 2) {
304 		tty_flag = TTY_NORMAL;
305 		lsr = data[i];
306 
307 		if (lsr & UART_LSR_BRK_ERROR_BITS) {
308 			if (lsr & UART_LSR_BI) {
309 				tty_flag = TTY_BREAK;
310 				port->icount.brk++;
311 				usb_serial_handle_break(port);
312 			} else if (lsr & UART_LSR_PE) {
313 				tty_flag = TTY_PARITY;
314 				port->icount.parity++;
315 			} else if (lsr & UART_LSR_FE) {
316 				tty_flag = TTY_FRAME;
317 				port->icount.frame++;
318 			}
319 
320 			if (lsr & UART_LSR_OE) {
321 				port->icount.overrun++;
322 				tty_insert_flip_char(&port->port, 0,
323 						TTY_OVERRUN);
324 			}
325 		}
326 
327 		if (port->port.console && port->sysrq) {
328 			if (usb_serial_handle_sysrq_char(port, data[i + 1]))
329 				continue;
330 		}
331 
332 		tty_insert_flip_char(&port->port, data[i + 1], tty_flag);
333 	}
334 
335 	tty_flip_buffer_push(&port->port);
336 }
337 
338 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
339 {
340 	/* FIXME - Stubbed out for now */
341 
342 	/*
343 	 * break_state = -1 to turn on break, and 0 to turn off break
344 	 * see drivers/char/tty_io.c to see it used.
345 	 * last_set_data_urb_value NEVER has the break bit set in it.
346 	 */
347 }
348 
349 static void f81232_set_baudrate(struct usb_serial_port *port, speed_t baudrate)
350 {
351 	u8 lcr;
352 	int divisor;
353 	int status = 0;
354 
355 	divisor = calc_baud_divisor(baudrate);
356 
357 	status = f81232_get_register(port, LINE_CONTROL_REGISTER,
358 			 &lcr); /* get LCR */
359 	if (status) {
360 		dev_err(&port->dev, "%s failed to get LCR: %d\n",
361 			__func__, status);
362 		return;
363 	}
364 
365 	status = f81232_set_register(port, LINE_CONTROL_REGISTER,
366 			 lcr | UART_LCR_DLAB); /* Enable DLAB */
367 	if (status) {
368 		dev_err(&port->dev, "%s failed to set DLAB: %d\n",
369 			__func__, status);
370 		return;
371 	}
372 
373 	status = f81232_set_register(port, RECEIVE_BUFFER_REGISTER,
374 			 divisor & 0x00ff); /* low */
375 	if (status) {
376 		dev_err(&port->dev, "%s failed to set baudrate MSB: %d\n",
377 			__func__, status);
378 		goto reapply_lcr;
379 	}
380 
381 	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
382 			 (divisor & 0xff00) >> 8); /* high */
383 	if (status) {
384 		dev_err(&port->dev, "%s failed to set baudrate LSB: %d\n",
385 			__func__, status);
386 	}
387 
388 reapply_lcr:
389 	status = f81232_set_register(port, LINE_CONTROL_REGISTER,
390 			lcr & ~UART_LCR_DLAB);
391 	if (status) {
392 		dev_err(&port->dev, "%s failed to set DLAB: %d\n",
393 			__func__, status);
394 	}
395 }
396 
397 static int f81232_port_enable(struct usb_serial_port *port)
398 {
399 	u8 val;
400 	int status;
401 
402 	/* fifo on, trigger8, clear TX/RX*/
403 	val = UART_FCR_TRIGGER_8 | UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
404 			UART_FCR_CLEAR_XMIT;
405 
406 	status = f81232_set_register(port, FIFO_CONTROL_REGISTER, val);
407 	if (status) {
408 		dev_err(&port->dev, "%s failed to set FCR: %d\n",
409 			__func__, status);
410 		return status;
411 	}
412 
413 	/* MSR Interrupt only, LSR will read from Bulk-in odd byte */
414 	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
415 			UART_IER_MSI);
416 	if (status) {
417 		dev_err(&port->dev, "%s failed to set IER: %d\n",
418 			__func__, status);
419 		return status;
420 	}
421 
422 	return 0;
423 }
424 
425 static int f81232_port_disable(struct usb_serial_port *port)
426 {
427 	int status;
428 
429 	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER, 0);
430 	if (status) {
431 		dev_err(&port->dev, "%s failed to set IER: %d\n",
432 			__func__, status);
433 		return status;
434 	}
435 
436 	return 0;
437 }
438 
439 static void f81232_set_termios(struct tty_struct *tty,
440 		struct usb_serial_port *port, struct ktermios *old_termios)
441 {
442 	u8 new_lcr = 0;
443 	int status = 0;
444 	speed_t baudrate;
445 
446 	/* Don't change anything if nothing has changed */
447 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
448 		return;
449 
450 	if (C_BAUD(tty) == B0)
451 		f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
452 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
453 		f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
454 
455 	baudrate = tty_get_baud_rate(tty);
456 	if (baudrate > 0) {
457 		if (baudrate > F81232_MAX_BAUDRATE) {
458 			baudrate = F81232_MAX_BAUDRATE;
459 			tty_encode_baud_rate(tty, baudrate, baudrate);
460 		}
461 		f81232_set_baudrate(port, baudrate);
462 	}
463 
464 	if (C_PARENB(tty)) {
465 		new_lcr |= UART_LCR_PARITY;
466 
467 		if (!C_PARODD(tty))
468 			new_lcr |= UART_LCR_EPAR;
469 
470 		if (C_CMSPAR(tty))
471 			new_lcr |= UART_LCR_SPAR;
472 	}
473 
474 	if (C_CSTOPB(tty))
475 		new_lcr |= UART_LCR_STOP;
476 
477 	switch (C_CSIZE(tty)) {
478 	case CS5:
479 		new_lcr |= UART_LCR_WLEN5;
480 		break;
481 	case CS6:
482 		new_lcr |= UART_LCR_WLEN6;
483 		break;
484 	case CS7:
485 		new_lcr |= UART_LCR_WLEN7;
486 		break;
487 	default:
488 	case CS8:
489 		new_lcr |= UART_LCR_WLEN8;
490 		break;
491 	}
492 
493 	status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
494 	if (status) {
495 		dev_err(&port->dev, "%s failed to set LCR: %d\n",
496 			__func__, status);
497 	}
498 }
499 
500 static int f81232_tiocmget(struct tty_struct *tty)
501 {
502 	int r;
503 	struct usb_serial_port *port = tty->driver_data;
504 	struct f81232_private *port_priv = usb_get_serial_port_data(port);
505 	u8 mcr, msr;
506 
507 	/* force get current MSR changed state */
508 	f81232_read_msr(port);
509 
510 	mutex_lock(&port_priv->lock);
511 	mcr = port_priv->modem_control;
512 	msr = port_priv->modem_status;
513 	mutex_unlock(&port_priv->lock);
514 
515 	r = (mcr & UART_MCR_DTR ? TIOCM_DTR : 0) |
516 		(mcr & UART_MCR_RTS ? TIOCM_RTS : 0) |
517 		(msr & UART_MSR_CTS ? TIOCM_CTS : 0) |
518 		(msr & UART_MSR_DCD ? TIOCM_CAR : 0) |
519 		(msr & UART_MSR_RI ? TIOCM_RI : 0) |
520 		(msr & UART_MSR_DSR ? TIOCM_DSR : 0);
521 
522 	return r;
523 }
524 
525 static int f81232_tiocmset(struct tty_struct *tty,
526 			unsigned int set, unsigned int clear)
527 {
528 	struct usb_serial_port *port = tty->driver_data;
529 
530 	return f81232_set_mctrl(port, set, clear);
531 }
532 
533 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
534 {
535 	int result;
536 
537 	result = f81232_port_enable(port);
538 	if (result)
539 		return result;
540 
541 	/* Setup termios */
542 	if (tty)
543 		f81232_set_termios(tty, port, NULL);
544 
545 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
546 	if (result) {
547 		dev_err(&port->dev, "%s - failed submitting interrupt urb,"
548 			" error %d\n", __func__, result);
549 		return result;
550 	}
551 
552 	result = usb_serial_generic_open(tty, port);
553 	if (result) {
554 		usb_kill_urb(port->interrupt_in_urb);
555 		return result;
556 	}
557 
558 	return 0;
559 }
560 
561 static void f81232_close(struct usb_serial_port *port)
562 {
563 	f81232_port_disable(port);
564 	usb_serial_generic_close(port);
565 	usb_kill_urb(port->interrupt_in_urb);
566 }
567 
568 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
569 {
570 	if (on)
571 		f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
572 	else
573 		f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
574 }
575 
576 static int f81232_carrier_raised(struct usb_serial_port *port)
577 {
578 	u8 msr;
579 	struct f81232_private *priv = usb_get_serial_port_data(port);
580 
581 	mutex_lock(&priv->lock);
582 	msr = priv->modem_status;
583 	mutex_unlock(&priv->lock);
584 
585 	if (msr & UART_MSR_DCD)
586 		return 1;
587 	return 0;
588 }
589 
590 static int f81232_get_serial_info(struct usb_serial_port *port,
591 		unsigned long arg)
592 {
593 	struct serial_struct ser;
594 
595 	memset(&ser, 0, sizeof(ser));
596 
597 	ser.type = PORT_16550A;
598 	ser.line = port->minor;
599 	ser.port = port->port_number;
600 	ser.baud_base = F81232_MAX_BAUDRATE;
601 
602 	if (copy_to_user((void __user *)arg, &ser, sizeof(ser)))
603 		return -EFAULT;
604 
605 	return 0;
606 }
607 
608 static int f81232_ioctl(struct tty_struct *tty,
609 			unsigned int cmd, unsigned long arg)
610 {
611 	struct usb_serial_port *port = tty->driver_data;
612 
613 	switch (cmd) {
614 	case TIOCGSERIAL:
615 		return f81232_get_serial_info(port, arg);
616 	default:
617 		break;
618 	}
619 	return -ENOIOCTLCMD;
620 }
621 
622 static void  f81232_interrupt_work(struct work_struct *work)
623 {
624 	struct f81232_private *priv =
625 		container_of(work, struct f81232_private, interrupt_work);
626 
627 	f81232_read_msr(priv->port);
628 }
629 
630 static int f81232_port_probe(struct usb_serial_port *port)
631 {
632 	struct f81232_private *priv;
633 
634 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
635 	if (!priv)
636 		return -ENOMEM;
637 
638 	mutex_init(&priv->lock);
639 	INIT_WORK(&priv->interrupt_work,  f81232_interrupt_work);
640 
641 	usb_set_serial_port_data(port, priv);
642 
643 	port->port.drain_delay = 256;
644 	priv->port = port;
645 
646 	return 0;
647 }
648 
649 static int f81232_port_remove(struct usb_serial_port *port)
650 {
651 	struct f81232_private *priv;
652 
653 	priv = usb_get_serial_port_data(port);
654 	kfree(priv);
655 
656 	return 0;
657 }
658 
659 static struct usb_serial_driver f81232_device = {
660 	.driver = {
661 		.owner =	THIS_MODULE,
662 		.name =		"f81232",
663 	},
664 	.id_table =		id_table,
665 	.num_ports =		1,
666 	.bulk_in_size =		256,
667 	.bulk_out_size =	256,
668 	.open =			f81232_open,
669 	.close =		f81232_close,
670 	.dtr_rts =		f81232_dtr_rts,
671 	.carrier_raised =	f81232_carrier_raised,
672 	.ioctl =		f81232_ioctl,
673 	.break_ctl =		f81232_break_ctl,
674 	.set_termios =		f81232_set_termios,
675 	.tiocmget =		f81232_tiocmget,
676 	.tiocmset =		f81232_tiocmset,
677 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
678 	.process_read_urb =	f81232_process_read_urb,
679 	.read_int_callback =	f81232_read_int_callback,
680 	.port_probe =		f81232_port_probe,
681 	.port_remove =		f81232_port_remove,
682 };
683 
684 static struct usb_serial_driver * const serial_drivers[] = {
685 	&f81232_device,
686 	NULL,
687 };
688 
689 module_usb_serial_driver(serial_drivers, id_table);
690 
691 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
692 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
693 MODULE_AUTHOR("Peter Hong <peter_hong@fintek.com.tw>");
694 MODULE_LICENSE("GPL v2");
695