xref: /openbmc/linux/drivers/usb/serial/f81232.c (revision ccb01374) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Fintek F81232 USB to serial adaptor driver
4  *
5  * Copyright (C) 2012 Greg Kroah-Hartman (gregkh@linuxfoundation.org)
6  * Copyright (C) 2012 Linux Foundation
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/errno.h>
11 #include <linux/slab.h>
12 #include <linux/tty.h>
13 #include <linux/tty_driver.h>
14 #include <linux/tty_flip.h>
15 #include <linux/serial.h>
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/mutex.h>
19 #include <linux/uaccess.h>
20 #include <linux/usb.h>
21 #include <linux/usb/serial.h>
22 #include <linux/serial_reg.h>
23 
24 static const struct usb_device_id id_table[] = {
25 	{ USB_DEVICE(0x1934, 0x0706) },
26 	{ }					/* Terminating entry */
27 };
28 MODULE_DEVICE_TABLE(usb, id_table);
29 
30 /* Maximum baudrate for F81232 */
31 #define F81232_MAX_BAUDRATE		115200
32 
33 /* USB Control EP parameter */
34 #define F81232_REGISTER_REQUEST		0xa0
35 #define F81232_GET_REGISTER		0xc0
36 #define F81232_SET_REGISTER		0x40
37 
38 #define SERIAL_BASE_ADDRESS		0x0120
39 #define RECEIVE_BUFFER_REGISTER		(0x00 + SERIAL_BASE_ADDRESS)
40 #define INTERRUPT_ENABLE_REGISTER	(0x01 + SERIAL_BASE_ADDRESS)
41 #define FIFO_CONTROL_REGISTER		(0x02 + SERIAL_BASE_ADDRESS)
42 #define LINE_CONTROL_REGISTER		(0x03 + SERIAL_BASE_ADDRESS)
43 #define MODEM_CONTROL_REGISTER		(0x04 + SERIAL_BASE_ADDRESS)
44 #define MODEM_STATUS_REGISTER		(0x06 + SERIAL_BASE_ADDRESS)
45 
46 struct f81232_private {
47 	struct mutex lock;
48 	u8 modem_control;
49 	u8 modem_status;
50 	struct work_struct interrupt_work;
51 	struct usb_serial_port *port;
52 };
53 
54 static int calc_baud_divisor(speed_t baudrate)
55 {
56 	return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);
57 }
58 
59 static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
60 {
61 	int status;
62 	u8 *tmp;
63 	struct usb_device *dev = port->serial->dev;
64 
65 	tmp = kmalloc(sizeof(*val), GFP_KERNEL);
66 	if (!tmp)
67 		return -ENOMEM;
68 
69 	status = usb_control_msg(dev,
70 				usb_rcvctrlpipe(dev, 0),
71 				F81232_REGISTER_REQUEST,
72 				F81232_GET_REGISTER,
73 				reg,
74 				0,
75 				tmp,
76 				sizeof(*val),
77 				USB_CTRL_GET_TIMEOUT);
78 	if (status != sizeof(*val)) {
79 		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
80 
81 		if (status < 0)
82 			status = usb_translate_errors(status);
83 		else
84 			status = -EIO;
85 	} else {
86 		status = 0;
87 		*val = *tmp;
88 	}
89 
90 	kfree(tmp);
91 	return status;
92 }
93 
94 static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val)
95 {
96 	int status;
97 	u8 *tmp;
98 	struct usb_device *dev = port->serial->dev;
99 
100 	tmp = kmalloc(sizeof(val), GFP_KERNEL);
101 	if (!tmp)
102 		return -ENOMEM;
103 
104 	*tmp = val;
105 
106 	status = usb_control_msg(dev,
107 				usb_sndctrlpipe(dev, 0),
108 				F81232_REGISTER_REQUEST,
109 				F81232_SET_REGISTER,
110 				reg,
111 				0,
112 				tmp,
113 				sizeof(val),
114 				USB_CTRL_SET_TIMEOUT);
115 	if (status != sizeof(val)) {
116 		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
117 
118 		if (status < 0)
119 			status = usb_translate_errors(status);
120 		else
121 			status = -EIO;
122 	} else {
123 		status = 0;
124 	}
125 
126 	kfree(tmp);
127 	return status;
128 }
129 
130 static void f81232_read_msr(struct usb_serial_port *port)
131 {
132 	int status;
133 	u8 current_msr;
134 	struct tty_struct *tty;
135 	struct f81232_private *priv = usb_get_serial_port_data(port);
136 
137 	mutex_lock(&priv->lock);
138 	status = f81232_get_register(port, MODEM_STATUS_REGISTER,
139 			&current_msr);
140 	if (status) {
141 		dev_err(&port->dev, "%s fail, status: %d\n", __func__, status);
142 		mutex_unlock(&priv->lock);
143 		return;
144 	}
145 
146 	if (!(current_msr & UART_MSR_ANY_DELTA)) {
147 		mutex_unlock(&priv->lock);
148 		return;
149 	}
150 
151 	priv->modem_status = current_msr;
152 
153 	if (current_msr & UART_MSR_DCTS)
154 		port->icount.cts++;
155 	if (current_msr & UART_MSR_DDSR)
156 		port->icount.dsr++;
157 	if (current_msr & UART_MSR_TERI)
158 		port->icount.rng++;
159 	if (current_msr & UART_MSR_DDCD) {
160 		port->icount.dcd++;
161 		tty = tty_port_tty_get(&port->port);
162 		if (tty) {
163 			usb_serial_handle_dcd_change(port, tty,
164 					current_msr & UART_MSR_DCD);
165 
166 			tty_kref_put(tty);
167 		}
168 	}
169 
170 	wake_up_interruptible(&port->port.delta_msr_wait);
171 	mutex_unlock(&priv->lock);
172 }
173 
174 static int f81232_set_mctrl(struct usb_serial_port *port,
175 					   unsigned int set, unsigned int clear)
176 {
177 	u8 val;
178 	int status;
179 	struct f81232_private *priv = usb_get_serial_port_data(port);
180 
181 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0)
182 		return 0;	/* no change */
183 
184 	/* 'set' takes precedence over 'clear' */
185 	clear &= ~set;
186 
187 	/* force enable interrupt with OUT2 */
188 	mutex_lock(&priv->lock);
189 	val = UART_MCR_OUT2 | priv->modem_control;
190 
191 	if (clear & TIOCM_DTR)
192 		val &= ~UART_MCR_DTR;
193 
194 	if (clear & TIOCM_RTS)
195 		val &= ~UART_MCR_RTS;
196 
197 	if (set & TIOCM_DTR)
198 		val |= UART_MCR_DTR;
199 
200 	if (set & TIOCM_RTS)
201 		val |= UART_MCR_RTS;
202 
203 	dev_dbg(&port->dev, "%s new:%02x old:%02x\n", __func__,
204 			val, priv->modem_control);
205 
206 	status = f81232_set_register(port, MODEM_CONTROL_REGISTER, val);
207 	if (status) {
208 		dev_err(&port->dev, "%s set MCR status < 0\n", __func__);
209 		mutex_unlock(&priv->lock);
210 		return status;
211 	}
212 
213 	priv->modem_control = val;
214 	mutex_unlock(&priv->lock);
215 
216 	return 0;
217 }
218 
219 static void f81232_update_line_status(struct usb_serial_port *port,
220 				      unsigned char *data,
221 				      size_t actual_length)
222 {
223 	struct f81232_private *priv = usb_get_serial_port_data(port);
224 
225 	if (!actual_length)
226 		return;
227 
228 	switch (data[0] & 0x07) {
229 	case 0x00: /* msr change */
230 		dev_dbg(&port->dev, "IIR: MSR Change: %02x\n", data[0]);
231 		schedule_work(&priv->interrupt_work);
232 		break;
233 	case 0x02: /* tx-empty */
234 		break;
235 	case 0x04: /* rx data available */
236 		break;
237 	case 0x06: /* lsr change */
238 		/* we can forget it. the LSR will read from bulk-in */
239 		dev_dbg(&port->dev, "IIR: LSR Change: %02x\n", data[0]);
240 		break;
241 	}
242 }
243 
244 static void f81232_read_int_callback(struct urb *urb)
245 {
246 	struct usb_serial_port *port =  urb->context;
247 	unsigned char *data = urb->transfer_buffer;
248 	unsigned int actual_length = urb->actual_length;
249 	int status = urb->status;
250 	int retval;
251 
252 	switch (status) {
253 	case 0:
254 		/* success */
255 		break;
256 	case -ECONNRESET:
257 	case -ENOENT:
258 	case -ESHUTDOWN:
259 		/* this urb is terminated, clean up */
260 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
261 			__func__, status);
262 		return;
263 	default:
264 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
265 			__func__, status);
266 		goto exit;
267 	}
268 
269 	usb_serial_debug_data(&port->dev, __func__,
270 			      urb->actual_length, urb->transfer_buffer);
271 
272 	f81232_update_line_status(port, data, actual_length);
273 
274 exit:
275 	retval = usb_submit_urb(urb, GFP_ATOMIC);
276 	if (retval)
277 		dev_err(&urb->dev->dev,
278 			"%s - usb_submit_urb failed with result %d\n",
279 			__func__, retval);
280 }
281 
282 static void f81232_process_read_urb(struct urb *urb)
283 {
284 	struct usb_serial_port *port = urb->context;
285 	unsigned char *data = urb->transfer_buffer;
286 	char tty_flag;
287 	unsigned int i;
288 	u8 lsr;
289 
290 	/*
291 	 * When opening the port we get a 1-byte packet with the current LSR,
292 	 * which we discard.
293 	 */
294 	if ((urb->actual_length < 2) || (urb->actual_length % 2))
295 		return;
296 
297 	/* bulk-in data: [LSR(1Byte)+DATA(1Byte)][LSR(1Byte)+DATA(1Byte)]... */
298 
299 	for (i = 0; i < urb->actual_length; i += 2) {
300 		tty_flag = TTY_NORMAL;
301 		lsr = data[i];
302 
303 		if (lsr & UART_LSR_BRK_ERROR_BITS) {
304 			if (lsr & UART_LSR_BI) {
305 				tty_flag = TTY_BREAK;
306 				port->icount.brk++;
307 				usb_serial_handle_break(port);
308 			} else if (lsr & UART_LSR_PE) {
309 				tty_flag = TTY_PARITY;
310 				port->icount.parity++;
311 			} else if (lsr & UART_LSR_FE) {
312 				tty_flag = TTY_FRAME;
313 				port->icount.frame++;
314 			}
315 
316 			if (lsr & UART_LSR_OE) {
317 				port->icount.overrun++;
318 				tty_insert_flip_char(&port->port, 0,
319 						TTY_OVERRUN);
320 			}
321 		}
322 
323 		if (port->port.console && port->sysrq) {
324 			if (usb_serial_handle_sysrq_char(port, data[i + 1]))
325 				continue;
326 		}
327 
328 		tty_insert_flip_char(&port->port, data[i + 1], tty_flag);
329 	}
330 
331 	tty_flip_buffer_push(&port->port);
332 }
333 
334 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
335 {
336 	/* FIXME - Stubbed out for now */
337 
338 	/*
339 	 * break_state = -1 to turn on break, and 0 to turn off break
340 	 * see drivers/char/tty_io.c to see it used.
341 	 * last_set_data_urb_value NEVER has the break bit set in it.
342 	 */
343 }
344 
345 static void f81232_set_baudrate(struct usb_serial_port *port, speed_t baudrate)
346 {
347 	u8 lcr;
348 	int divisor;
349 	int status = 0;
350 
351 	divisor = calc_baud_divisor(baudrate);
352 
353 	status = f81232_get_register(port, LINE_CONTROL_REGISTER,
354 			 &lcr); /* get LCR */
355 	if (status) {
356 		dev_err(&port->dev, "%s failed to get LCR: %d\n",
357 			__func__, status);
358 		return;
359 	}
360 
361 	status = f81232_set_register(port, LINE_CONTROL_REGISTER,
362 			 lcr | UART_LCR_DLAB); /* Enable DLAB */
363 	if (status) {
364 		dev_err(&port->dev, "%s failed to set DLAB: %d\n",
365 			__func__, status);
366 		return;
367 	}
368 
369 	status = f81232_set_register(port, RECEIVE_BUFFER_REGISTER,
370 			 divisor & 0x00ff); /* low */
371 	if (status) {
372 		dev_err(&port->dev, "%s failed to set baudrate MSB: %d\n",
373 			__func__, status);
374 		goto reapply_lcr;
375 	}
376 
377 	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
378 			 (divisor & 0xff00) >> 8); /* high */
379 	if (status) {
380 		dev_err(&port->dev, "%s failed to set baudrate LSB: %d\n",
381 			__func__, status);
382 	}
383 
384 reapply_lcr:
385 	status = f81232_set_register(port, LINE_CONTROL_REGISTER,
386 			lcr & ~UART_LCR_DLAB);
387 	if (status) {
388 		dev_err(&port->dev, "%s failed to set DLAB: %d\n",
389 			__func__, status);
390 	}
391 }
392 
393 static int f81232_port_enable(struct usb_serial_port *port)
394 {
395 	u8 val;
396 	int status;
397 
398 	/* fifo on, trigger8, clear TX/RX*/
399 	val = UART_FCR_TRIGGER_8 | UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
400 			UART_FCR_CLEAR_XMIT;
401 
402 	status = f81232_set_register(port, FIFO_CONTROL_REGISTER, val);
403 	if (status) {
404 		dev_err(&port->dev, "%s failed to set FCR: %d\n",
405 			__func__, status);
406 		return status;
407 	}
408 
409 	/* MSR Interrupt only, LSR will read from Bulk-in odd byte */
410 	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
411 			UART_IER_MSI);
412 	if (status) {
413 		dev_err(&port->dev, "%s failed to set IER: %d\n",
414 			__func__, status);
415 		return status;
416 	}
417 
418 	return 0;
419 }
420 
421 static int f81232_port_disable(struct usb_serial_port *port)
422 {
423 	int status;
424 
425 	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER, 0);
426 	if (status) {
427 		dev_err(&port->dev, "%s failed to set IER: %d\n",
428 			__func__, status);
429 		return status;
430 	}
431 
432 	return 0;
433 }
434 
435 static void f81232_set_termios(struct tty_struct *tty,
436 		struct usb_serial_port *port, struct ktermios *old_termios)
437 {
438 	u8 new_lcr = 0;
439 	int status = 0;
440 	speed_t baudrate;
441 
442 	/* Don't change anything if nothing has changed */
443 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
444 		return;
445 
446 	if (C_BAUD(tty) == B0)
447 		f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
448 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
449 		f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
450 
451 	baudrate = tty_get_baud_rate(tty);
452 	if (baudrate > 0) {
453 		if (baudrate > F81232_MAX_BAUDRATE) {
454 			baudrate = F81232_MAX_BAUDRATE;
455 			tty_encode_baud_rate(tty, baudrate, baudrate);
456 		}
457 		f81232_set_baudrate(port, baudrate);
458 	}
459 
460 	if (C_PARENB(tty)) {
461 		new_lcr |= UART_LCR_PARITY;
462 
463 		if (!C_PARODD(tty))
464 			new_lcr |= UART_LCR_EPAR;
465 
466 		if (C_CMSPAR(tty))
467 			new_lcr |= UART_LCR_SPAR;
468 	}
469 
470 	if (C_CSTOPB(tty))
471 		new_lcr |= UART_LCR_STOP;
472 
473 	switch (C_CSIZE(tty)) {
474 	case CS5:
475 		new_lcr |= UART_LCR_WLEN5;
476 		break;
477 	case CS6:
478 		new_lcr |= UART_LCR_WLEN6;
479 		break;
480 	case CS7:
481 		new_lcr |= UART_LCR_WLEN7;
482 		break;
483 	default:
484 	case CS8:
485 		new_lcr |= UART_LCR_WLEN8;
486 		break;
487 	}
488 
489 	status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
490 	if (status) {
491 		dev_err(&port->dev, "%s failed to set LCR: %d\n",
492 			__func__, status);
493 	}
494 }
495 
496 static int f81232_tiocmget(struct tty_struct *tty)
497 {
498 	int r;
499 	struct usb_serial_port *port = tty->driver_data;
500 	struct f81232_private *port_priv = usb_get_serial_port_data(port);
501 	u8 mcr, msr;
502 
503 	/* force get current MSR changed state */
504 	f81232_read_msr(port);
505 
506 	mutex_lock(&port_priv->lock);
507 	mcr = port_priv->modem_control;
508 	msr = port_priv->modem_status;
509 	mutex_unlock(&port_priv->lock);
510 
511 	r = (mcr & UART_MCR_DTR ? TIOCM_DTR : 0) |
512 		(mcr & UART_MCR_RTS ? TIOCM_RTS : 0) |
513 		(msr & UART_MSR_CTS ? TIOCM_CTS : 0) |
514 		(msr & UART_MSR_DCD ? TIOCM_CAR : 0) |
515 		(msr & UART_MSR_RI ? TIOCM_RI : 0) |
516 		(msr & UART_MSR_DSR ? TIOCM_DSR : 0);
517 
518 	return r;
519 }
520 
521 static int f81232_tiocmset(struct tty_struct *tty,
522 			unsigned int set, unsigned int clear)
523 {
524 	struct usb_serial_port *port = tty->driver_data;
525 
526 	return f81232_set_mctrl(port, set, clear);
527 }
528 
529 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
530 {
531 	int result;
532 
533 	result = f81232_port_enable(port);
534 	if (result)
535 		return result;
536 
537 	/* Setup termios */
538 	if (tty)
539 		f81232_set_termios(tty, port, NULL);
540 
541 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
542 	if (result) {
543 		dev_err(&port->dev, "%s - failed submitting interrupt urb,"
544 			" error %d\n", __func__, result);
545 		return result;
546 	}
547 
548 	result = usb_serial_generic_open(tty, port);
549 	if (result) {
550 		usb_kill_urb(port->interrupt_in_urb);
551 		return result;
552 	}
553 
554 	return 0;
555 }
556 
557 static void f81232_close(struct usb_serial_port *port)
558 {
559 	f81232_port_disable(port);
560 	usb_serial_generic_close(port);
561 	usb_kill_urb(port->interrupt_in_urb);
562 }
563 
564 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
565 {
566 	if (on)
567 		f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
568 	else
569 		f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
570 }
571 
572 static int f81232_carrier_raised(struct usb_serial_port *port)
573 {
574 	u8 msr;
575 	struct f81232_private *priv = usb_get_serial_port_data(port);
576 
577 	mutex_lock(&priv->lock);
578 	msr = priv->modem_status;
579 	mutex_unlock(&priv->lock);
580 
581 	if (msr & UART_MSR_DCD)
582 		return 1;
583 	return 0;
584 }
585 
586 static int f81232_get_serial_info(struct tty_struct *tty,
587 		struct serial_struct *ss)
588 {
589 	struct usb_serial_port *port = tty->driver_data;
590 
591 	ss->type = PORT_16550A;
592 	ss->line = port->minor;
593 	ss->port = port->port_number;
594 	ss->baud_base = F81232_MAX_BAUDRATE;
595 	return 0;
596 }
597 
598 static void  f81232_interrupt_work(struct work_struct *work)
599 {
600 	struct f81232_private *priv =
601 		container_of(work, struct f81232_private, interrupt_work);
602 
603 	f81232_read_msr(priv->port);
604 }
605 
606 static int f81232_port_probe(struct usb_serial_port *port)
607 {
608 	struct f81232_private *priv;
609 
610 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
611 	if (!priv)
612 		return -ENOMEM;
613 
614 	mutex_init(&priv->lock);
615 	INIT_WORK(&priv->interrupt_work,  f81232_interrupt_work);
616 
617 	usb_set_serial_port_data(port, priv);
618 
619 	port->port.drain_delay = 256;
620 	priv->port = port;
621 
622 	return 0;
623 }
624 
625 static int f81232_port_remove(struct usb_serial_port *port)
626 {
627 	struct f81232_private *priv;
628 
629 	priv = usb_get_serial_port_data(port);
630 	kfree(priv);
631 
632 	return 0;
633 }
634 
635 static struct usb_serial_driver f81232_device = {
636 	.driver = {
637 		.owner =	THIS_MODULE,
638 		.name =		"f81232",
639 	},
640 	.id_table =		id_table,
641 	.num_ports =		1,
642 	.bulk_in_size =		256,
643 	.bulk_out_size =	256,
644 	.open =			f81232_open,
645 	.close =		f81232_close,
646 	.dtr_rts =		f81232_dtr_rts,
647 	.carrier_raised =	f81232_carrier_raised,
648 	.get_serial =		f81232_get_serial_info,
649 	.break_ctl =		f81232_break_ctl,
650 	.set_termios =		f81232_set_termios,
651 	.tiocmget =		f81232_tiocmget,
652 	.tiocmset =		f81232_tiocmset,
653 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
654 	.process_read_urb =	f81232_process_read_urb,
655 	.read_int_callback =	f81232_read_int_callback,
656 	.port_probe =		f81232_port_probe,
657 	.port_remove =		f81232_port_remove,
658 };
659 
660 static struct usb_serial_driver * const serial_drivers[] = {
661 	&f81232_device,
662 	NULL,
663 };
664 
665 module_usb_serial_driver(serial_drivers, id_table);
666 
667 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
668 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
669 MODULE_AUTHOR("Peter Hong <peter_hong@fintek.com.tw>");
670 MODULE_LICENSE("GPL v2");
671