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
calc_baud_divisor(speed_t baudrate)54 static int calc_baud_divisor(speed_t baudrate)
55 {
56 return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);
57 }
58
f81232_get_register(struct usb_serial_port * port,u16 reg,u8 * val)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
f81232_set_register(struct usb_serial_port * port,u16 reg,u8 val)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
f81232_read_msr(struct usb_serial_port * port)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 ¤t_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
f81232_set_mctrl(struct usb_serial_port * port,unsigned int set,unsigned int clear)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
f81232_update_line_status(struct usb_serial_port * port,unsigned char * data,size_t actual_length)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
f81232_read_int_callback(struct urb * urb)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
f81232_process_read_urb(struct urb * urb)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
f81232_break_ctl(struct tty_struct * tty,int break_state)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
f81232_set_baudrate(struct usb_serial_port * port,speed_t baudrate)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
f81232_port_enable(struct usb_serial_port * port)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
f81232_port_disable(struct usb_serial_port * port)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
f81232_set_termios(struct tty_struct * tty,struct usb_serial_port * port,struct ktermios * old_termios)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
f81232_tiocmget(struct tty_struct * tty)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
f81232_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)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
f81232_open(struct tty_struct * tty,struct usb_serial_port * port)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
f81232_close(struct usb_serial_port * port)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
f81232_dtr_rts(struct usb_serial_port * port,int on)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
f81232_carrier_raised(struct usb_serial_port * port)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
f81232_get_serial_info(struct usb_serial_port * port,unsigned long arg)586 static int f81232_get_serial_info(struct usb_serial_port *port,
587 unsigned long arg)
588 {
589 struct serial_struct ser;
590
591 memset(&ser, 0, sizeof(ser));
592
593 ser.type = PORT_16550A;
594 ser.line = port->minor;
595 ser.port = port->port_number;
596 ser.baud_base = F81232_MAX_BAUDRATE;
597
598 if (copy_to_user((void __user *)arg, &ser, sizeof(ser)))
599 return -EFAULT;
600
601 return 0;
602 }
603
f81232_ioctl(struct tty_struct * tty,unsigned int cmd,unsigned long arg)604 static int f81232_ioctl(struct tty_struct *tty,
605 unsigned int cmd, unsigned long arg)
606 {
607 struct usb_serial_port *port = tty->driver_data;
608
609 switch (cmd) {
610 case TIOCGSERIAL:
611 return f81232_get_serial_info(port, arg);
612 default:
613 break;
614 }
615 return -ENOIOCTLCMD;
616 }
617
f81232_interrupt_work(struct work_struct * work)618 static void f81232_interrupt_work(struct work_struct *work)
619 {
620 struct f81232_private *priv =
621 container_of(work, struct f81232_private, interrupt_work);
622
623 f81232_read_msr(priv->port);
624 }
625
f81232_port_probe(struct usb_serial_port * port)626 static int f81232_port_probe(struct usb_serial_port *port)
627 {
628 struct f81232_private *priv;
629
630 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
631 if (!priv)
632 return -ENOMEM;
633
634 mutex_init(&priv->lock);
635 INIT_WORK(&priv->interrupt_work, f81232_interrupt_work);
636
637 usb_set_serial_port_data(port, priv);
638
639 port->port.drain_delay = 256;
640 priv->port = port;
641
642 return 0;
643 }
644
f81232_port_remove(struct usb_serial_port * port)645 static int f81232_port_remove(struct usb_serial_port *port)
646 {
647 struct f81232_private *priv;
648
649 priv = usb_get_serial_port_data(port);
650 kfree(priv);
651
652 return 0;
653 }
654
655 static struct usb_serial_driver f81232_device = {
656 .driver = {
657 .owner = THIS_MODULE,
658 .name = "f81232",
659 },
660 .id_table = id_table,
661 .num_ports = 1,
662 .bulk_in_size = 256,
663 .bulk_out_size = 256,
664 .open = f81232_open,
665 .close = f81232_close,
666 .dtr_rts = f81232_dtr_rts,
667 .carrier_raised = f81232_carrier_raised,
668 .ioctl = f81232_ioctl,
669 .break_ctl = f81232_break_ctl,
670 .set_termios = f81232_set_termios,
671 .tiocmget = f81232_tiocmget,
672 .tiocmset = f81232_tiocmset,
673 .tiocmiwait = usb_serial_generic_tiocmiwait,
674 .process_read_urb = f81232_process_read_urb,
675 .read_int_callback = f81232_read_int_callback,
676 .port_probe = f81232_port_probe,
677 .port_remove = f81232_port_remove,
678 };
679
680 static struct usb_serial_driver * const serial_drivers[] = {
681 &f81232_device,
682 NULL,
683 };
684
685 module_usb_serial_driver(serial_drivers, id_table);
686
687 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
688 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
689 MODULE_AUTHOR("Peter Hong <peter_hong@fintek.com.tw>");
690 MODULE_LICENSE("GPL v2");
691