USB: ch341: set tty baud speed according to tty struct
[pandora-kernel.git] / drivers / usb / serial / ch341.c
1 /*
2  * Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
3  * Copyright 2007, Werner Cornelius <werner@cornelius-consult.de>
4  * Copyright 2009, Boris Hajduk <boris@hajduk.org>
5  *
6  * ch341.c implements a serial port driver for the Winchiphead CH341.
7  *
8  * The CH341 device can be used to implement an RS232 asynchronous
9  * serial port, an IEEE-1284 parallel printer port or a memory-like
10  * interface. In all cases the CH341 supports an I2C interface as well.
11  * This driver only supports the asynchronous serial interface.
12  *
13  * This program is free software; you can redistribute it and/or
14  * modify it under the terms of the GNU General Public License version
15  * 2 as published by the Free Software Foundation.
16  */
17
18 #include <linux/kernel.h>
19 #include <linux/init.h>
20 #include <linux/tty.h>
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/usb.h>
24 #include <linux/usb/serial.h>
25 #include <linux/serial.h>
26 #include <asm/unaligned.h>
27
28 #define DEFAULT_BAUD_RATE 9600
29 #define DEFAULT_TIMEOUT   1000
30
31 /* flags for IO-Bits */
32 #define CH341_BIT_RTS (1 << 6)
33 #define CH341_BIT_DTR (1 << 5)
34
35 /******************************/
36 /* interrupt pipe definitions */
37 /******************************/
38 /* always 4 interrupt bytes */
39 /* first irq byte normally 0x08 */
40 /* second irq byte base 0x7d + below */
41 /* third irq byte base 0x94 + below */
42 /* fourth irq byte normally 0xee */
43
44 /* second interrupt byte */
45 #define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
46
47 /* status returned in third interrupt answer byte, inverted in data
48    from irq */
49 #define CH341_BIT_CTS 0x01
50 #define CH341_BIT_DSR 0x02
51 #define CH341_BIT_RI  0x04
52 #define CH341_BIT_DCD 0x08
53 #define CH341_BITS_MODEM_STAT 0x0f /* all bits */
54
55 /*******************************/
56 /* baudrate calculation factor */
57 /*******************************/
58 #define CH341_BAUDBASE_FACTOR 1532620800
59 #define CH341_BAUDBASE_DIVMAX 3
60
61 /* Break support - the information used to implement this was gleaned from
62  * the Net/FreeBSD uchcom.c driver by Takanori Watanabe.  Domo arigato.
63  */
64
65 #define CH341_REQ_WRITE_REG    0x9A
66 #define CH341_REQ_READ_REG     0x95
67 #define CH341_REG_BREAK1       0x05
68 #define CH341_REG_BREAK2       0x18
69 #define CH341_NBREAK_BITS_REG1 0x01
70 #define CH341_NBREAK_BITS_REG2 0x40
71
72
73 static int debug;
74
75 static const struct usb_device_id id_table[] = {
76         { USB_DEVICE(0x4348, 0x5523) },
77         { USB_DEVICE(0x1a86, 0x7523) },
78         { USB_DEVICE(0x1a86, 0x5523) },
79         { },
80 };
81 MODULE_DEVICE_TABLE(usb, id_table);
82
83 struct ch341_private {
84         spinlock_t lock; /* access lock */
85         unsigned baud_rate; /* set baud rate */
86         u8 line_control; /* set line control value RTS/DTR */
87         u8 line_status; /* active status of modem control inputs */
88         u8 multi_status_change; /* status changed multiple since last call */
89 };
90
91 static void ch341_set_termios(struct tty_struct *tty,
92                               struct usb_serial_port *port,
93                               struct ktermios *old_termios);
94
95 static int ch341_control_out(struct usb_device *dev, u8 request,
96                              u16 value, u16 index)
97 {
98         int r;
99         dbg("ch341_control_out(%02x,%02x,%04x,%04x)", USB_DIR_OUT|0x40,
100                 (int)request, (int)value, (int)index);
101
102         r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
103                             USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
104                             value, index, NULL, 0, DEFAULT_TIMEOUT);
105
106         return r;
107 }
108
109 static int ch341_control_in(struct usb_device *dev,
110                             u8 request, u16 value, u16 index,
111                             char *buf, unsigned bufsize)
112 {
113         int r;
114         dbg("ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)", USB_DIR_IN|0x40,
115                 (int)request, (int)value, (int)index, buf, (int)bufsize);
116
117         r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
118                             USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
119                             value, index, buf, bufsize, DEFAULT_TIMEOUT);
120         return r;
121 }
122
123 static int ch341_set_baudrate(struct usb_device *dev,
124                               struct ch341_private *priv)
125 {
126         short a, b;
127         int r;
128         unsigned long factor;
129         short divisor;
130
131         dbg("ch341_set_baudrate(%d)", priv->baud_rate);
132
133         if (!priv->baud_rate)
134                 return -EINVAL;
135         factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
136         divisor = CH341_BAUDBASE_DIVMAX;
137
138         while ((factor > 0xfff0) && divisor) {
139                 factor >>= 3;
140                 divisor--;
141         }
142
143         if (factor > 0xfff0)
144                 return -EINVAL;
145
146         factor = 0x10000 - factor;
147         a = (factor & 0xff00) | divisor;
148         b = factor & 0xff;
149
150         r = ch341_control_out(dev, 0x9a, 0x1312, a);
151         if (!r)
152                 r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
153
154         return r;
155 }
156
157 static int ch341_set_handshake(struct usb_device *dev, u8 control)
158 {
159         dbg("ch341_set_handshake(0x%02x)", control);
160         return ch341_control_out(dev, 0xa4, ~control, 0);
161 }
162
163 static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
164 {
165         char *buffer;
166         int r;
167         const unsigned size = 8;
168         unsigned long flags;
169
170         dbg("ch341_get_status()");
171
172         buffer = kmalloc(size, GFP_KERNEL);
173         if (!buffer)
174                 return -ENOMEM;
175
176         r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
177         if (r < 0)
178                 goto out;
179
180         /* setup the private status if available */
181         if (r == 2) {
182                 r = 0;
183                 spin_lock_irqsave(&priv->lock, flags);
184                 priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
185                 priv->multi_status_change = 0;
186                 spin_unlock_irqrestore(&priv->lock, flags);
187         } else
188                 r = -EPROTO;
189
190 out:    kfree(buffer);
191         return r;
192 }
193
194 /* -------------------------------------------------------------------------- */
195
196 static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
197 {
198         char *buffer;
199         int r;
200         const unsigned size = 8;
201
202         dbg("ch341_configure()");
203
204         buffer = kmalloc(size, GFP_KERNEL);
205         if (!buffer)
206                 return -ENOMEM;
207
208         /* expect two bytes 0x27 0x00 */
209         r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
210         if (r < 0)
211                 goto out;
212
213         r = ch341_control_out(dev, 0xa1, 0, 0);
214         if (r < 0)
215                 goto out;
216
217         r = ch341_set_baudrate(dev, priv);
218         if (r < 0)
219                 goto out;
220
221         /* expect two bytes 0x56 0x00 */
222         r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
223         if (r < 0)
224                 goto out;
225
226         r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
227         if (r < 0)
228                 goto out;
229
230         /* expect 0xff 0xee */
231         r = ch341_get_status(dev, priv);
232         if (r < 0)
233                 goto out;
234
235         r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
236         if (r < 0)
237                 goto out;
238
239         r = ch341_set_baudrate(dev, priv);
240         if (r < 0)
241                 goto out;
242
243         r = ch341_set_handshake(dev, priv->line_control);
244         if (r < 0)
245                 goto out;
246
247         /* expect 0x9f 0xee */
248         r = ch341_get_status(dev, priv);
249
250 out:    kfree(buffer);
251         return r;
252 }
253
254 /* allocate private data */
255 static int ch341_attach(struct usb_serial *serial)
256 {
257         struct ch341_private *priv;
258         int r;
259
260         dbg("ch341_attach()");
261
262         /* private data */
263         priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
264         if (!priv)
265                 return -ENOMEM;
266
267         spin_lock_init(&priv->lock);
268         priv->baud_rate = DEFAULT_BAUD_RATE;
269         priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
270
271         r = ch341_configure(serial->dev, priv);
272         if (r < 0)
273                 goto error;
274
275         usb_set_serial_port_data(serial->port[0], priv);
276         return 0;
277
278 error:  kfree(priv);
279         return r;
280 }
281
282 static int ch341_carrier_raised(struct usb_serial_port *port)
283 {
284         struct ch341_private *priv = usb_get_serial_port_data(port);
285         if (priv->line_status & CH341_BIT_DCD)
286                 return 1;
287         return 0;
288 }
289
290 static void ch341_dtr_rts(struct usb_serial_port *port, int on)
291 {
292         struct ch341_private *priv = usb_get_serial_port_data(port);
293         unsigned long flags;
294
295         dbg("%s - port %d", __func__, port->number);
296         /* drop DTR and RTS */
297         spin_lock_irqsave(&priv->lock, flags);
298         if (on)
299                 priv->line_control |= CH341_BIT_RTS | CH341_BIT_DTR;
300         else
301                 priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
302         spin_unlock_irqrestore(&priv->lock, flags);
303         ch341_set_handshake(port->serial->dev, priv->line_control);
304         wake_up_interruptible(&port->delta_msr_wait);
305 }
306
307 static void ch341_close(struct usb_serial_port *port)
308 {
309         dbg("%s - port %d", __func__, port->number);
310
311         usb_serial_generic_close(port);
312         usb_kill_urb(port->interrupt_in_urb);
313 }
314
315
316 /* open this device, set default parameters */
317 static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
318 {
319         struct usb_serial *serial = port->serial;
320         struct ch341_private *priv = usb_get_serial_port_data(serial->port[0]);
321         int r;
322
323         dbg("ch341_open()");
324
325         r = ch341_configure(serial->dev, priv);
326         if (r)
327                 goto out;
328
329         if (tty)
330                 ch341_set_termios(tty, port, NULL);
331
332         dbg("%s - submitting interrupt urb", __func__);
333         port->interrupt_in_urb->dev = serial->dev;
334         r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
335         if (r) {
336                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
337                         " error %d\n", __func__, r);
338                 goto out;
339         }
340
341         r = usb_serial_generic_open(tty, port);
342
343 out:    return r;
344 }
345
346 /* Old_termios contains the original termios settings and
347  * tty->termios contains the new setting to be used.
348  */
349 static void ch341_set_termios(struct tty_struct *tty,
350                 struct usb_serial_port *port, struct ktermios *old_termios)
351 {
352         struct ch341_private *priv = usb_get_serial_port_data(port);
353         unsigned baud_rate;
354         unsigned long flags;
355
356         dbg("ch341_set_termios()");
357
358         baud_rate = tty_get_baud_rate(tty);
359
360         priv->baud_rate = baud_rate;
361
362         if (baud_rate) {
363                 spin_lock_irqsave(&priv->lock, flags);
364                 priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
365                 spin_unlock_irqrestore(&priv->lock, flags);
366                 ch341_set_baudrate(port->serial->dev, priv);
367         } else {
368                 spin_lock_irqsave(&priv->lock, flags);
369                 priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
370                 spin_unlock_irqrestore(&priv->lock, flags);
371         }
372
373         ch341_set_handshake(port->serial->dev, priv->line_control);
374
375         /* Unimplemented:
376          * (cflag & CSIZE) : data bits [5, 8]
377          * (cflag & PARENB) : parity {NONE, EVEN, ODD}
378          * (cflag & CSTOPB) : stop bits [1, 2]
379          */
380 }
381
382 static void ch341_break_ctl(struct tty_struct *tty, int break_state)
383 {
384         const uint16_t ch341_break_reg =
385                 CH341_REG_BREAK1 | ((uint16_t) CH341_REG_BREAK2 << 8);
386         struct usb_serial_port *port = tty->driver_data;
387         int r;
388         uint16_t reg_contents;
389         uint8_t *break_reg;
390
391         dbg("%s()", __func__);
392
393         break_reg = kmalloc(2, GFP_KERNEL);
394         if (!break_reg) {
395                 dev_err(&port->dev, "%s - kmalloc failed\n", __func__);
396                 return;
397         }
398
399         r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
400                         ch341_break_reg, 0, break_reg, 2);
401         if (r < 0) {
402                 dev_err(&port->dev, "%s - USB control read error (%d)\n",
403                                 __func__, r);
404                 goto out;
405         }
406         dbg("%s - initial ch341 break register contents - reg1: %x, reg2: %x",
407                         __func__, break_reg[0], break_reg[1]);
408         if (break_state != 0) {
409                 dbg("%s - Enter break state requested", __func__);
410                 break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
411                 break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
412         } else {
413                 dbg("%s - Leave break state requested", __func__);
414                 break_reg[0] |= CH341_NBREAK_BITS_REG1;
415                 break_reg[1] |= CH341_NBREAK_BITS_REG2;
416         }
417         dbg("%s - New ch341 break register contents - reg1: %x, reg2: %x",
418                         __func__, break_reg[0], break_reg[1]);
419         reg_contents = get_unaligned_le16(break_reg);
420         r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
421                         ch341_break_reg, reg_contents);
422         if (r < 0)
423                 dev_err(&port->dev, "%s - USB control write error (%d)\n",
424                                 __func__, r);
425 out:
426         kfree(break_reg);
427 }
428
429 static int ch341_tiocmset(struct tty_struct *tty,
430                           unsigned int set, unsigned int clear)
431 {
432         struct usb_serial_port *port = tty->driver_data;
433         struct ch341_private *priv = usb_get_serial_port_data(port);
434         unsigned long flags;
435         u8 control;
436
437         spin_lock_irqsave(&priv->lock, flags);
438         if (set & TIOCM_RTS)
439                 priv->line_control |= CH341_BIT_RTS;
440         if (set & TIOCM_DTR)
441                 priv->line_control |= CH341_BIT_DTR;
442         if (clear & TIOCM_RTS)
443                 priv->line_control &= ~CH341_BIT_RTS;
444         if (clear & TIOCM_DTR)
445                 priv->line_control &= ~CH341_BIT_DTR;
446         control = priv->line_control;
447         spin_unlock_irqrestore(&priv->lock, flags);
448
449         return ch341_set_handshake(port->serial->dev, control);
450 }
451
452 static void ch341_read_int_callback(struct urb *urb)
453 {
454         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
455         unsigned char *data = urb->transfer_buffer;
456         unsigned int actual_length = urb->actual_length;
457         int status;
458
459         dbg("%s (%d)", __func__, port->number);
460
461         switch (urb->status) {
462         case 0:
463                 /* success */
464                 break;
465         case -ECONNRESET:
466         case -ENOENT:
467         case -ESHUTDOWN:
468                 /* this urb is terminated, clean up */
469                 dbg("%s - urb shutting down with status: %d", __func__,
470                     urb->status);
471                 return;
472         default:
473                 dbg("%s - nonzero urb status received: %d", __func__,
474                     urb->status);
475                 goto exit;
476         }
477
478         usb_serial_debug_data(debug, &port->dev, __func__,
479                               urb->actual_length, urb->transfer_buffer);
480
481         if (actual_length >= 4) {
482                 struct ch341_private *priv = usb_get_serial_port_data(port);
483                 unsigned long flags;
484                 u8 prev_line_status = priv->line_status;
485
486                 spin_lock_irqsave(&priv->lock, flags);
487                 priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
488                 if ((data[1] & CH341_MULT_STAT))
489                         priv->multi_status_change = 1;
490                 spin_unlock_irqrestore(&priv->lock, flags);
491
492                 if ((priv->line_status ^ prev_line_status) & CH341_BIT_DCD) {
493                         struct tty_struct *tty = tty_port_tty_get(&port->port);
494                         if (tty)
495                                 usb_serial_handle_dcd_change(port, tty,
496                                             priv->line_status & CH341_BIT_DCD);
497                         tty_kref_put(tty);
498                 }
499
500                 wake_up_interruptible(&port->delta_msr_wait);
501         }
502
503 exit:
504         status = usb_submit_urb(urb, GFP_ATOMIC);
505         if (status)
506                 dev_err(&urb->dev->dev,
507                         "%s - usb_submit_urb failed with result %d\n",
508                         __func__, status);
509 }
510
511 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
512 {
513         struct ch341_private *priv = usb_get_serial_port_data(port);
514         unsigned long flags;
515         u8 prevstatus;
516         u8 status;
517         u8 changed;
518         u8 multi_change = 0;
519
520         spin_lock_irqsave(&priv->lock, flags);
521         prevstatus = priv->line_status;
522         priv->multi_status_change = 0;
523         spin_unlock_irqrestore(&priv->lock, flags);
524
525         while (!multi_change) {
526                 interruptible_sleep_on(&port->delta_msr_wait);
527                 /* see if a signal did it */
528                 if (signal_pending(current))
529                         return -ERESTARTSYS;
530
531                 if (port->serial->disconnected)
532                         return -EIO;
533
534                 spin_lock_irqsave(&priv->lock, flags);
535                 status = priv->line_status;
536                 multi_change = priv->multi_status_change;
537                 spin_unlock_irqrestore(&priv->lock, flags);
538
539                 changed = prevstatus ^ status;
540
541                 if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) ||
542                     ((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) ||
543                     ((arg & TIOCM_CD)  && (changed & CH341_BIT_DCD)) ||
544                     ((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {
545                         return 0;
546                 }
547                 prevstatus = status;
548         }
549
550         return 0;
551 }
552
553 static int ch341_ioctl(struct tty_struct *tty,
554                         unsigned int cmd, unsigned long arg)
555 {
556         struct usb_serial_port *port = tty->driver_data;
557         dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);
558
559         switch (cmd) {
560         case TIOCMIWAIT:
561                 dbg("%s (%d) TIOCMIWAIT", __func__,  port->number);
562                 return wait_modem_info(port, arg);
563
564         default:
565                 dbg("%s not supported = 0x%04x", __func__, cmd);
566                 break;
567         }
568
569         return -ENOIOCTLCMD;
570 }
571
572 static int ch341_tiocmget(struct tty_struct *tty)
573 {
574         struct usb_serial_port *port = tty->driver_data;
575         struct ch341_private *priv = usb_get_serial_port_data(port);
576         unsigned long flags;
577         u8 mcr;
578         u8 status;
579         unsigned int result;
580
581         dbg("%s (%d)", __func__, port->number);
582
583         spin_lock_irqsave(&priv->lock, flags);
584         mcr = priv->line_control;
585         status = priv->line_status;
586         spin_unlock_irqrestore(&priv->lock, flags);
587
588         result = ((mcr & CH341_BIT_DTR)         ? TIOCM_DTR : 0)
589                   | ((mcr & CH341_BIT_RTS)      ? TIOCM_RTS : 0)
590                   | ((status & CH341_BIT_CTS)   ? TIOCM_CTS : 0)
591                   | ((status & CH341_BIT_DSR)   ? TIOCM_DSR : 0)
592                   | ((status & CH341_BIT_RI)    ? TIOCM_RI  : 0)
593                   | ((status & CH341_BIT_DCD)   ? TIOCM_CD  : 0);
594
595         dbg("%s - result = %x", __func__, result);
596
597         return result;
598 }
599
600
601 static int ch341_reset_resume(struct usb_interface *intf)
602 {
603         struct usb_device *dev = interface_to_usbdev(intf);
604         struct usb_serial *serial = NULL;
605         struct ch341_private *priv;
606
607         serial = usb_get_intfdata(intf);
608         priv = usb_get_serial_port_data(serial->port[0]);
609
610         /*reconfigure ch341 serial port after bus-reset*/
611         ch341_configure(dev, priv);
612
613         usb_serial_resume(intf);
614
615         return 0;
616 }
617
618 static struct usb_driver ch341_driver = {
619         .name           = "ch341",
620         .probe          = usb_serial_probe,
621         .disconnect     = usb_serial_disconnect,
622         .suspend        = usb_serial_suspend,
623         .resume         = usb_serial_resume,
624         .reset_resume   = ch341_reset_resume,
625         .id_table       = id_table,
626         .no_dynamic_id  = 1,
627         .supports_autosuspend = 1,
628 };
629
630 static struct usb_serial_driver ch341_device = {
631         .driver = {
632                 .owner  = THIS_MODULE,
633                 .name   = "ch341-uart",
634         },
635         .id_table          = id_table,
636         .usb_driver        = &ch341_driver,
637         .num_ports         = 1,
638         .open              = ch341_open,
639         .dtr_rts           = ch341_dtr_rts,
640         .carrier_raised    = ch341_carrier_raised,
641         .close             = ch341_close,
642         .ioctl             = ch341_ioctl,
643         .set_termios       = ch341_set_termios,
644         .break_ctl         = ch341_break_ctl,
645         .tiocmget          = ch341_tiocmget,
646         .tiocmset          = ch341_tiocmset,
647         .read_int_callback = ch341_read_int_callback,
648         .attach            = ch341_attach,
649 };
650
651 static int __init ch341_init(void)
652 {
653         int retval;
654
655         retval = usb_serial_register(&ch341_device);
656         if (retval)
657                 return retval;
658         retval = usb_register(&ch341_driver);
659         if (retval)
660                 usb_serial_deregister(&ch341_device);
661         return retval;
662 }
663
664 static void __exit ch341_exit(void)
665 {
666         usb_deregister(&ch341_driver);
667         usb_serial_deregister(&ch341_device);
668 }
669
670 module_init(ch341_init);
671 module_exit(ch341_exit);
672 MODULE_LICENSE("GPL");
673
674 module_param(debug, bool, S_IRUGO | S_IWUSR);
675 MODULE_PARM_DESC(debug, "Debug enabled or not");
676
677 /* EOF ch341.c */