xref: /linux/drivers/usb/serial/f81232.c (revision 5fd54ace4721fc5ce2bb5aef6318fcf17f421460) 
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  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License version 2 as published by
10  * the Free Software Foundation.
11  *
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/tty.h>
18 #include <linux/tty_driver.h>
19 #include <linux/tty_flip.h>
20 #include <linux/serial.h>
21 #include <linux/module.h>
22 #include <linux/moduleparam.h>
23 #include <linux/mutex.h>
24 #include <linux/uaccess.h>
25 #include <linux/usb.h>
26 #include <linux/usb/serial.h>
27 #include <linux/serial_reg.h>
28 
29 static const struct usb_device_id id_table[] = {
30 	{ USB_DEVICE(0x1934, 0x0706) },
31 	{ }					/* Terminating entry */
32 };
33 MODULE_DEVICE_TABLE(usb, id_table);
34 
35 /* Maximum baudrate for F81232 */
36 #define F81232_MAX_BAUDRATE		115200
37 
38 /* USB Control EP parameter */
39 #define F81232_REGISTER_REQUEST		0xa0
40 #define F81232_GET_REGISTER		0xc0
41 #define F81232_SET_REGISTER		0x40
42 
43 #define SERIAL_BASE_ADDRESS		0x0120
44 #define RECEIVE_BUFFER_REGISTER		(0x00 + SERIAL_BASE_ADDRESS)
45 #define INTERRUPT_ENABLE_REGISTER	(0x01 + SERIAL_BASE_ADDRESS)
46 #define FIFO_CONTROL_REGISTER		(0x02 + SERIAL_BASE_ADDRESS)
47 #define LINE_CONTROL_REGISTER		(0x03 + SERIAL_BASE_ADDRESS)
48 #define MODEM_CONTROL_REGISTER		(0x04 + SERIAL_BASE_ADDRESS)
49 #define MODEM_STATUS_REGISTER		(0x06 + SERIAL_BASE_ADDRESS)
50 
51 struct f81232_private {
52 	struct mutex lock;
53 	u8 modem_control;
54 	u8 modem_status;
55 	struct work_struct interrupt_work;
56 	struct usb_serial_port *port;
57 };
58 
59 static int calc_baud_divisor(speed_t baudrate)
60 {
61 	return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);
62 }
63 
64 static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
65 {
66 	int status;
67 	u8 *tmp;
68 	struct usb_device *dev = port->serial->dev;
69 
70 	tmp = kmalloc(sizeof(*val), GFP_KERNEL);
71 	if (!tmp)
72 		return -ENOMEM;
73 
74 	status = usb_control_msg(dev,
75 				usb_rcvctrlpipe(dev, 0),
76 				F81232_REGISTER_REQUEST,
77 				F81232_GET_REGISTER,
78 				reg,
79 				0,
80 				tmp,
81 				sizeof(*val),
82 				USB_CTRL_GET_TIMEOUT);
83 	if (status != sizeof(*val)) {
84 		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
85 
86 		if (status < 0)
87 			status = usb_translate_errors(status);
88 		else
89 			status = -EIO;
90 	} else {
91 		status = 0;
92 		*val = *tmp;
93 	}
94 
95 	kfree(tmp);
96 	return status;
97 }
98 
99 static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val)
100 {
101 	int status;
102 	u8 *tmp;
103 	struct usb_device *dev = port->serial->dev;
104 
105 	tmp = kmalloc(sizeof(val), GFP_KERNEL);
106 	if (!tmp)
107 		return -ENOMEM;
108 
109 	*tmp = val;
110 
111 	status = usb_control_msg(dev,
112 				usb_sndctrlpipe(dev, 0),
113 				F81232_REGISTER_REQUEST,
114 				F81232_SET_REGISTER,
115 				reg,
116 				0,
117 				tmp,
118 				sizeof(val),
119 				USB_CTRL_SET_TIMEOUT);
120 	if (status != sizeof(val)) {
121 		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
122 
123 		if (status < 0)
124 			status = usb_translate_errors(status);
125 		else
126 			status = -EIO;
127 	} else {
128 		status = 0;
129 	}
130 
131 	kfree(tmp);
132 	return status;
133 }
134 
135 static void f81232_read_msr(struct usb_serial_port *port)
136 {
137 	int status;
138 	u8 current_msr;
139 	struct tty_struct *tty;
140 	struct f81232_private *priv = usb_get_serial_port_data(port);
141 
142 	mutex_lock(&priv->lock);
143 	status = f81232_get_register(port, MODEM_STATUS_REGISTER,
144 			&current_msr);
145 	if (status) {
146 		dev_err(&port->dev, "%s fail, status: %d\n", __func__, status);
147 		mutex_unlock(&priv->lock);
148 		return;
149 	}
150 
151 	if (!(current_msr & UART_MSR_ANY_DELTA)) {
152 		mutex_unlock(&priv->lock);
153 		return;
154 	}
155 
156 	priv->modem_status = current_msr;
157 
158 	if (current_msr & UART_MSR_DCTS)
159 		port->icount.cts++;
160 	if (current_msr & UART_MSR_DDSR)
161 		port->icount.dsr++;
162 	if (current_msr & UART_MSR_TERI)
163 		port->icount.rng++;
164 	if (current_msr & UART_MSR_DDCD) {
165 		port->icount.dcd++;
166 		tty = tty_port_tty_get(&port->port);
167 		if (tty) {
168 			usb_serial_handle_dcd_change(port, tty,
169 					current_msr & UART_MSR_DCD);
170 
171 			tty_kref_put(tty);
172 		}
173 	}
174 
175 	wake_up_interruptible(&port->port.delta_msr_wait);
176 	mutex_unlock(&priv->lock);
177 }
178 
179 static int f81232_set_mctrl(struct usb_serial_port *port,
180 					   unsigned int set, unsigned int clear)
181 {
182 	u8 val;
183 	int status;
184 	struct f81232_private *priv = usb_get_serial_port_data(port);
185 
186 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0)
187 		return 0;	/* no change */
188 
189 	/* 'set' takes precedence over 'clear' */
190 	clear &= ~set;
191 
192 	/* force enable interrupt with OUT2 */
193 	mutex_lock(&priv->lock);
194 	val = UART_MCR_OUT2 | priv->modem_control;
195 
196 	if (clear & TIOCM_DTR)
197 		val &= ~UART_MCR_DTR;
198 
199 	if (clear & TIOCM_RTS)
200 		val &= ~UART_MCR_RTS;
201 
202 	if (set & TIOCM_DTR)
203 		val |= UART_MCR_DTR;
204 
205 	if (set & TIOCM_RTS)
206 		val |= UART_MCR_RTS;
207 
208 	dev_dbg(&port->dev, "%s new:%02x old:%02x\n", __func__,
209 			val, priv->modem_control);
210 
211 	status = f81232_set_register(port, MODEM_CONTROL_REGISTER, val);
212 	if (status) {
213 		dev_err(&port->dev, "%s set MCR status < 0\n", __func__);
214 		mutex_unlock(&priv->lock);
215 		return status;
216 	}
217 
218 	priv->modem_control = val;
219 	mutex_unlock(&priv->lock);
220 
221 	return 0;
222 }
223 
224 static void f81232_update_line_status(struct usb_serial_port *port,
225 				      unsigned char *data,
226 				      size_t actual_length)
227 {
228 	struct f81232_private *priv = usb_get_serial_port_data(port);
229 
230 	if (!actual_length)
231 		return;
232 
233 	switch (data[0] & 0x07) {
234 	case 0x00: /* msr change */
235 		dev_dbg(&port->dev, "IIR: MSR Change: %02x\n", data[0]);
236 		schedule_work(&priv->interrupt_work);
237 		break;
238 	case 0x02: /* tx-empty */
239 		break;
240 	case 0x04: /* rx data available */
241 		break;
242 	case 0x06: /* lsr change */
243 		/* we can forget it. the LSR will read from bulk-in */
244 		dev_dbg(&port->dev, "IIR: LSR Change: %02x\n", data[0]);
245 		break;
246 	}
247 }
248 
249 static void f81232_read_int_callback(struct urb *urb)
250 {
251 	struct usb_serial_port *port =  urb->context;
252 	unsigned char *data = urb->transfer_buffer;
253 	unsigned int actual_length = urb->actual_length;
254 	int status = urb->status;
255 	int retval;
256 
257 	switch (status) {
258 	case 0:
259 		/* success */
260 		break;
261 	case -ECONNRESET:
262 	case -ENOENT:
263 	case -ESHUTDOWN:
264 		/* this urb is terminated, clean up */
265 		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
266 			__func__, status);
267 		return;
268 	default:
269 		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
270 			__func__, status);
271 		goto exit;
272 	}
273 
274 	usb_serial_debug_data(&port->dev, __func__,
275 			      urb->actual_length, urb->transfer_buffer);
276 
277 	f81232_update_line_status(port, data, actual_length);
278 
279 exit:
280 	retval = usb_submit_urb(urb, GFP_ATOMIC);
281 	if (retval)
282 		dev_err(&urb->dev->dev,
283 			"%s - usb_submit_urb failed with result %d\n",
284 			__func__, retval);
285 }
286 
287 static void f81232_process_read_urb(struct urb *urb)
288 {
289 	struct usb_serial_port *port = urb->context;
290 	unsigned char *data = urb->transfer_buffer;
291 	char tty_flag;
292 	unsigned int i;
293 	u8 lsr;
294 
295 	/*
296 	 * When opening the port we get a 1-byte packet with the current LSR,
297 	 * which we discard.
298 	 */
299 	if ((urb->actual_length < 2) || (urb->actual_length % 2))
300 		return;
301 
302 	/* bulk-in data: [LSR(1Byte)+DATA(1Byte)][LSR(1Byte)+DATA(1Byte)]... */
303 
304 	for (i = 0; i < urb->actual_length; i += 2) {
305 		tty_flag = TTY_NORMAL;
306 		lsr = data[i];
307 
308 		if (lsr & UART_LSR_BRK_ERROR_BITS) {
309 			if (lsr & UART_LSR_BI) {
310 				tty_flag = TTY_BREAK;
311 				port->icount.brk++;
312 				usb_serial_handle_break(port);
313 			} else if (lsr & UART_LSR_PE) {
314 				tty_flag = TTY_PARITY;
315 				port->icount.parity++;
316 			} else if (lsr & UART_LSR_FE) {
317 				tty_flag = TTY_FRAME;
318 				port->icount.frame++;
319 			}
320 
321 			if (lsr & UART_LSR_OE) {
322 				port->icount.overrun++;
323 				tty_insert_flip_char(&port->port, 0,
324 						TTY_OVERRUN);
325 			}
326 		}
327 
328 		if (port->port.console && port->sysrq) {
329 			if (usb_serial_handle_sysrq_char(port, data[i + 1]))
330 				continue;
331 		}
332 
333 		tty_insert_flip_char(&port->port, data[i + 1], tty_flag);
334 	}
335 
336 	tty_flip_buffer_push(&port->port);
337 }
338 
339 static void f81232_break_ctl(struct tty_struct *tty, int break_state)
340 {
341 	/* FIXME - Stubbed out for now */
342 
343 	/*
344 	 * break_state = -1 to turn on break, and 0 to turn off break
345 	 * see drivers/char/tty_io.c to see it used.
346 	 * last_set_data_urb_value NEVER has the break bit set in it.
347 	 */
348 }
349 
350 static void f81232_set_baudrate(struct usb_serial_port *port, speed_t baudrate)
351 {
352 	u8 lcr;
353 	int divisor;
354 	int status = 0;
355 
356 	divisor = calc_baud_divisor(baudrate);
357 
358 	status = f81232_get_register(port, LINE_CONTROL_REGISTER,
359 			 &lcr); /* get LCR */
360 	if (status) {
361 		dev_err(&port->dev, "%s failed to get LCR: %d\n",
362 			__func__, status);
363 		return;
364 	}
365 
366 	status = f81232_set_register(port, LINE_CONTROL_REGISTER,
367 			 lcr | UART_LCR_DLAB); /* Enable DLAB */
368 	if (status) {
369 		dev_err(&port->dev, "%s failed to set DLAB: %d\n",
370 			__func__, status);
371 		return;
372 	}
373 
374 	status = f81232_set_register(port, RECEIVE_BUFFER_REGISTER,
375 			 divisor & 0x00ff); /* low */
376 	if (status) {
377 		dev_err(&port->dev, "%s failed to set baudrate MSB: %d\n",
378 			__func__, status);
379 		goto reapply_lcr;
380 	}
381 
382 	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
383 			 (divisor & 0xff00) >> 8); /* high */
384 	if (status) {
385 		dev_err(&port->dev, "%s failed to set baudrate LSB: %d\n",
386 			__func__, status);
387 	}
388 
389 reapply_lcr:
390 	status = f81232_set_register(port, LINE_CONTROL_REGISTER,
391 			lcr & ~UART_LCR_DLAB);
392 	if (status) {
393 		dev_err(&port->dev, "%s failed to set DLAB: %d\n",
394 			__func__, status);
395 	}
396 }
397 
398 static int f81232_port_enable(struct usb_serial_port *port)
399 {
400 	u8 val;
401 	int status;
402 
403 	/* fifo on, trigger8, clear TX/RX*/
404 	val = UART_FCR_TRIGGER_8 | UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
405 			UART_FCR_CLEAR_XMIT;
406 
407 	status = f81232_set_register(port, FIFO_CONTROL_REGISTER, val);
408 	if (status) {
409 		dev_err(&port->dev, "%s failed to set FCR: %d\n",
410 			__func__, status);
411 		return status;
412 	}
413 
414 	/* MSR Interrupt only, LSR will read from Bulk-in odd byte */
415 	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
416 			UART_IER_MSI);
417 	if (status) {
418 		dev_err(&port->dev, "%s failed to set IER: %d\n",
419 			__func__, status);
420 		return status;
421 	}
422 
423 	return 0;
424 }
425 
426 static int f81232_port_disable(struct usb_serial_port *port)
427 {
428 	int status;
429 
430 	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER, 0);
431 	if (status) {
432 		dev_err(&port->dev, "%s failed to set IER: %d\n",
433 			__func__, status);
434 		return status;
435 	}
436 
437 	return 0;
438 }
439 
440 static void f81232_set_termios(struct tty_struct *tty,
441 		struct usb_serial_port *port, struct ktermios *old_termios)
442 {
443 	u8 new_lcr = 0;
444 	int status = 0;
445 	speed_t baudrate;
446 
447 	/* Don't change anything if nothing has changed */
448 	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
449 		return;
450 
451 	if (C_BAUD(tty) == B0)
452 		f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
453 	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
454 		f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
455 
456 	baudrate = tty_get_baud_rate(tty);
457 	if (baudrate > 0) {
458 		if (baudrate > F81232_MAX_BAUDRATE) {
459 			baudrate = F81232_MAX_BAUDRATE;
460 			tty_encode_baud_rate(tty, baudrate, baudrate);
461 		}
462 		f81232_set_baudrate(port, baudrate);
463 	}
464 
465 	if (C_PARENB(tty)) {
466 		new_lcr |= UART_LCR_PARITY;
467 
468 		if (!C_PARODD(tty))
469 			new_lcr |= UART_LCR_EPAR;
470 
471 		if (C_CMSPAR(tty))
472 			new_lcr |= UART_LCR_SPAR;
473 	}
474 
475 	if (C_CSTOPB(tty))
476 		new_lcr |= UART_LCR_STOP;
477 
478 	switch (C_CSIZE(tty)) {
479 	case CS5:
480 		new_lcr |= UART_LCR_WLEN5;
481 		break;
482 	case CS6:
483 		new_lcr |= UART_LCR_WLEN6;
484 		break;
485 	case CS7:
486 		new_lcr |= UART_LCR_WLEN7;
487 		break;
488 	default:
489 	case CS8:
490 		new_lcr |= UART_LCR_WLEN8;
491 		break;
492 	}
493 
494 	status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
495 	if (status) {
496 		dev_err(&port->dev, "%s failed to set LCR: %d\n",
497 			__func__, status);
498 	}
499 }
500 
501 static int f81232_tiocmget(struct tty_struct *tty)
502 {
503 	int r;
504 	struct usb_serial_port *port = tty->driver_data;
505 	struct f81232_private *port_priv = usb_get_serial_port_data(port);
506 	u8 mcr, msr;
507 
508 	/* force get current MSR changed state */
509 	f81232_read_msr(port);
510 
511 	mutex_lock(&port_priv->lock);
512 	mcr = port_priv->modem_control;
513 	msr = port_priv->modem_status;
514 	mutex_unlock(&port_priv->lock);
515 
516 	r = (mcr & UART_MCR_DTR ? TIOCM_DTR : 0) |
517 		(mcr & UART_MCR_RTS ? TIOCM_RTS : 0) |
518 		(msr & UART_MSR_CTS ? TIOCM_CTS : 0) |
519 		(msr & UART_MSR_DCD ? TIOCM_CAR : 0) |
520 		(msr & UART_MSR_RI ? TIOCM_RI : 0) |
521 		(msr & UART_MSR_DSR ? TIOCM_DSR : 0);
522 
523 	return r;
524 }
525 
526 static int f81232_tiocmset(struct tty_struct *tty,
527 			unsigned int set, unsigned int clear)
528 {
529 	struct usb_serial_port *port = tty->driver_data;
530 
531 	return f81232_set_mctrl(port, set, clear);
532 }
533 
534 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
535 {
536 	int result;
537 
538 	result = f81232_port_enable(port);
539 	if (result)
540 		return result;
541 
542 	/* Setup termios */
543 	if (tty)
544 		f81232_set_termios(tty, port, NULL);
545 
546 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
547 	if (result) {
548 		dev_err(&port->dev, "%s - failed submitting interrupt urb,"
549 			" error %d\n", __func__, result);
550 		return result;
551 	}
552 
553 	result = usb_serial_generic_open(tty, port);
554 	if (result) {
555 		usb_kill_urb(port->interrupt_in_urb);
556 		return result;
557 	}
558 
559 	return 0;
560 }
561 
562 static void f81232_close(struct usb_serial_port *port)
563 {
564 	f81232_port_disable(port);
565 	usb_serial_generic_close(port);
566 	usb_kill_urb(port->interrupt_in_urb);
567 }
568 
569 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
570 {
571 	if (on)
572 		f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
573 	else
574 		f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
575 }
576 
577 static int f81232_carrier_raised(struct usb_serial_port *port)
578 {
579 	u8 msr;
580 	struct f81232_private *priv = usb_get_serial_port_data(port);
581 
582 	mutex_lock(&priv->lock);
583 	msr = priv->modem_status;
584 	mutex_unlock(&priv->lock);
585 
586 	if (msr & UART_MSR_DCD)
587 		return 1;
588 	return 0;
589 }
590 
591 static int f81232_get_serial_info(struct usb_serial_port *port,
592 		unsigned long arg)
593 {
594 	struct serial_struct ser;
595 
596 	memset(&ser, 0, sizeof(ser));
597 
598 	ser.type = PORT_16550A;
599 	ser.line = port->minor;
600 	ser.port = port->port_number;
601 	ser.baud_base = F81232_MAX_BAUDRATE;
602 
603 	if (copy_to_user((void __user *)arg, &ser, sizeof(ser)))
604 		return -EFAULT;
605 
606 	return 0;
607 }
608 
609 static int f81232_ioctl(struct tty_struct *tty,
610 			unsigned int cmd, unsigned long arg)
611 {
612 	struct usb_serial_port *port = tty->driver_data;
613 
614 	switch (cmd) {
615 	case TIOCGSERIAL:
616 		return f81232_get_serial_info(port, arg);
617 	default:
618 		break;
619 	}
620 	return -ENOIOCTLCMD;
621 }
622 
623 static void  f81232_interrupt_work(struct work_struct *work)
624 {
625 	struct f81232_private *priv =
626 		container_of(work, struct f81232_private, interrupt_work);
627 
628 	f81232_read_msr(priv->port);
629 }
630 
631 static int f81232_port_probe(struct usb_serial_port *port)
632 {
633 	struct f81232_private *priv;
634 
635 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
636 	if (!priv)
637 		return -ENOMEM;
638 
639 	mutex_init(&priv->lock);
640 	INIT_WORK(&priv->interrupt_work,  f81232_interrupt_work);
641 
642 	usb_set_serial_port_data(port, priv);
643 
644 	port->port.drain_delay = 256;
645 	priv->port = port;
646 
647 	return 0;
648 }
649 
650 static int f81232_port_remove(struct usb_serial_port *port)
651 {
652 	struct f81232_private *priv;
653 
654 	priv = usb_get_serial_port_data(port);
655 	kfree(priv);
656 
657 	return 0;
658 }
659 
660 static struct usb_serial_driver f81232_device = {
661 	.driver = {
662 		.owner =	THIS_MODULE,
663 		.name =		"f81232",
664 	},
665 	.id_table =		id_table,
666 	.num_ports =		1,
667 	.bulk_in_size =		256,
668 	.bulk_out_size =	256,
669 	.open =			f81232_open,
670 	.close =		f81232_close,
671 	.dtr_rts =		f81232_dtr_rts,
672 	.carrier_raised =	f81232_carrier_raised,
673 	.ioctl =		f81232_ioctl,
674 	.break_ctl =		f81232_break_ctl,
675 	.set_termios =		f81232_set_termios,
676 	.tiocmget =		f81232_tiocmget,
677 	.tiocmset =		f81232_tiocmset,
678 	.tiocmiwait =		usb_serial_generic_tiocmiwait,
679 	.process_read_urb =	f81232_process_read_urb,
680 	.read_int_callback =	f81232_read_int_callback,
681 	.port_probe =		f81232_port_probe,
682 	.port_remove =		f81232_port_remove,
683 };
684 
685 static struct usb_serial_driver * const serial_drivers[] = {
686 	&f81232_device,
687 	NULL,
688 };
689 
690 module_usb_serial_driver(serial_drivers, id_table);
691 
692 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
693 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
694 MODULE_AUTHOR("Peter Hong <peter_hong@fintek.com.tw>");
695 MODULE_LICENSE("GPL v2");
696