GNU Linux-libre 4.19.286-gnu1
[releases.git] / drivers / usb / serial / f81232.c
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         struct f81232_private *port_priv = usb_get_serial_port_data(port);
560
561         f81232_port_disable(port);
562         usb_serial_generic_close(port);
563         usb_kill_urb(port->interrupt_in_urb);
564         flush_work(&port_priv->interrupt_work);
565 }
566
567 static void f81232_dtr_rts(struct usb_serial_port *port, int on)
568 {
569         if (on)
570                 f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
571         else
572                 f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
573 }
574
575 static int f81232_carrier_raised(struct usb_serial_port *port)
576 {
577         u8 msr;
578         struct f81232_private *priv = usb_get_serial_port_data(port);
579
580         mutex_lock(&priv->lock);
581         msr = priv->modem_status;
582         mutex_unlock(&priv->lock);
583
584         if (msr & UART_MSR_DCD)
585                 return 1;
586         return 0;
587 }
588
589 static int f81232_get_serial_info(struct usb_serial_port *port,
590                 unsigned long arg)
591 {
592         struct serial_struct ser;
593
594         memset(&ser, 0, sizeof(ser));
595
596         ser.type = PORT_16550A;
597         ser.line = port->minor;
598         ser.port = port->port_number;
599         ser.baud_base = F81232_MAX_BAUDRATE;
600
601         if (copy_to_user((void __user *)arg, &ser, sizeof(ser)))
602                 return -EFAULT;
603
604         return 0;
605 }
606
607 static int f81232_ioctl(struct tty_struct *tty,
608                         unsigned int cmd, unsigned long arg)
609 {
610         struct usb_serial_port *port = tty->driver_data;
611
612         switch (cmd) {
613         case TIOCGSERIAL:
614                 return f81232_get_serial_info(port, arg);
615         default:
616                 break;
617         }
618         return -ENOIOCTLCMD;
619 }
620
621 static void  f81232_interrupt_work(struct work_struct *work)
622 {
623         struct f81232_private *priv =
624                 container_of(work, struct f81232_private, interrupt_work);
625
626         f81232_read_msr(priv->port);
627 }
628
629 static int f81232_port_probe(struct usb_serial_port *port)
630 {
631         struct f81232_private *priv;
632
633         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
634         if (!priv)
635                 return -ENOMEM;
636
637         mutex_init(&priv->lock);
638         INIT_WORK(&priv->interrupt_work,  f81232_interrupt_work);
639
640         usb_set_serial_port_data(port, priv);
641
642         port->port.drain_delay = 256;
643         priv->port = port;
644
645         return 0;
646 }
647
648 static int f81232_port_remove(struct usb_serial_port *port)
649 {
650         struct f81232_private *priv;
651
652         priv = usb_get_serial_port_data(port);
653         kfree(priv);
654
655         return 0;
656 }
657
658 static int f81232_suspend(struct usb_serial *serial, pm_message_t message)
659 {
660         struct usb_serial_port *port = serial->port[0];
661         struct f81232_private *port_priv = usb_get_serial_port_data(port);
662         int i;
663
664         for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
665                 usb_kill_urb(port->read_urbs[i]);
666
667         usb_kill_urb(port->interrupt_in_urb);
668
669         if (port_priv)
670                 flush_work(&port_priv->interrupt_work);
671
672         return 0;
673 }
674
675 static int f81232_resume(struct usb_serial *serial)
676 {
677         struct usb_serial_port *port = serial->port[0];
678         int result;
679
680         if (tty_port_initialized(&port->port)) {
681                 result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
682                 if (result) {
683                         dev_err(&port->dev, "submit interrupt urb failed: %d\n",
684                                         result);
685                         return result;
686                 }
687         }
688
689         return usb_serial_generic_resume(serial);
690 }
691
692 static struct usb_serial_driver f81232_device = {
693         .driver = {
694                 .owner =        THIS_MODULE,
695                 .name =         "f81232",
696         },
697         .id_table =             id_table,
698         .num_ports =            1,
699         .bulk_in_size =         256,
700         .bulk_out_size =        256,
701         .open =                 f81232_open,
702         .close =                f81232_close,
703         .dtr_rts =              f81232_dtr_rts,
704         .carrier_raised =       f81232_carrier_raised,
705         .ioctl =                f81232_ioctl,
706         .break_ctl =            f81232_break_ctl,
707         .set_termios =          f81232_set_termios,
708         .tiocmget =             f81232_tiocmget,
709         .tiocmset =             f81232_tiocmset,
710         .tiocmiwait =           usb_serial_generic_tiocmiwait,
711         .process_read_urb =     f81232_process_read_urb,
712         .read_int_callback =    f81232_read_int_callback,
713         .port_probe =           f81232_port_probe,
714         .port_remove =          f81232_port_remove,
715         .suspend =              f81232_suspend,
716         .resume =               f81232_resume,
717 };
718
719 static struct usb_serial_driver * const serial_drivers[] = {
720         &f81232_device,
721         NULL,
722 };
723
724 module_usb_serial_driver(serial_drivers, id_table);
725
726 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
727 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
728 MODULE_AUTHOR("Peter Hong <peter_hong@fintek.com.tw>");
729 MODULE_LICENSE("GPL v2");