USB: serial: ch341: add new id
[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         wait_queue_head_t delta_msr_wait; /* wait queue for modem status */
86         unsigned baud_rate; /* set baud rate */
87         u8 line_control; /* set line control value RTS/DTR */
88         u8 line_status; /* active status of modem control inputs */
89         u8 multi_status_change; /* status changed multiple since last call */
90 };
91
92 static int ch341_control_out(struct usb_device *dev, u8 request,
93                              u16 value, u16 index)
94 {
95         int r;
96         dbg("ch341_control_out(%02x,%02x,%04x,%04x)", USB_DIR_OUT|0x40,
97                 (int)request, (int)value, (int)index);
98
99         r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
100                             USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
101                             value, index, NULL, 0, DEFAULT_TIMEOUT);
102
103         return r;
104 }
105
106 static int ch341_control_in(struct usb_device *dev,
107                             u8 request, u16 value, u16 index,
108                             char *buf, unsigned bufsize)
109 {
110         int r;
111         dbg("ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)", USB_DIR_IN|0x40,
112                 (int)request, (int)value, (int)index, buf, (int)bufsize);
113
114         r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
115                             USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
116                             value, index, buf, bufsize, DEFAULT_TIMEOUT);
117         return r;
118 }
119
120 static int ch341_set_baudrate(struct usb_device *dev,
121                               struct ch341_private *priv)
122 {
123         short a, b;
124         int r;
125         unsigned long factor;
126         short divisor;
127
128         dbg("ch341_set_baudrate(%d)", priv->baud_rate);
129
130         if (!priv->baud_rate)
131                 return -EINVAL;
132         factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
133         divisor = CH341_BAUDBASE_DIVMAX;
134
135         while ((factor > 0xfff0) && divisor) {
136                 factor >>= 3;
137                 divisor--;
138         }
139
140         if (factor > 0xfff0)
141                 return -EINVAL;
142
143         factor = 0x10000 - factor;
144         a = (factor & 0xff00) | divisor;
145         b = factor & 0xff;
146
147         r = ch341_control_out(dev, 0x9a, 0x1312, a);
148         if (!r)
149                 r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
150
151         return r;
152 }
153
154 static int ch341_set_handshake(struct usb_device *dev, u8 control)
155 {
156         dbg("ch341_set_handshake(0x%02x)", control);
157         return ch341_control_out(dev, 0xa4, ~control, 0);
158 }
159
160 static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
161 {
162         char *buffer;
163         int r;
164         const unsigned size = 8;
165         unsigned long flags;
166
167         dbg("ch341_get_status()");
168
169         buffer = kmalloc(size, GFP_KERNEL);
170         if (!buffer)
171                 return -ENOMEM;
172
173         r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
174         if (r < 0)
175                 goto out;
176
177         /* setup the private status if available */
178         if (r == 2) {
179                 r = 0;
180                 spin_lock_irqsave(&priv->lock, flags);
181                 priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
182                 priv->multi_status_change = 0;
183                 spin_unlock_irqrestore(&priv->lock, flags);
184         } else
185                 r = -EPROTO;
186
187 out:    kfree(buffer);
188         return r;
189 }
190
191 /* -------------------------------------------------------------------------- */
192
193 static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
194 {
195         char *buffer;
196         int r;
197         const unsigned size = 8;
198
199         dbg("ch341_configure()");
200
201         buffer = kmalloc(size, GFP_KERNEL);
202         if (!buffer)
203                 return -ENOMEM;
204
205         /* expect two bytes 0x27 0x00 */
206         r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
207         if (r < 0)
208                 goto out;
209
210         r = ch341_control_out(dev, 0xa1, 0, 0);
211         if (r < 0)
212                 goto out;
213
214         r = ch341_set_baudrate(dev, priv);
215         if (r < 0)
216                 goto out;
217
218         /* expect two bytes 0x56 0x00 */
219         r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
220         if (r < 0)
221                 goto out;
222
223         r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
224         if (r < 0)
225                 goto out;
226
227         /* expect 0xff 0xee */
228         r = ch341_get_status(dev, priv);
229         if (r < 0)
230                 goto out;
231
232         r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
233         if (r < 0)
234                 goto out;
235
236         r = ch341_set_baudrate(dev, priv);
237         if (r < 0)
238                 goto out;
239
240         r = ch341_set_handshake(dev, priv->line_control);
241         if (r < 0)
242                 goto out;
243
244         /* expect 0x9f 0xee */
245         r = ch341_get_status(dev, priv);
246
247 out:    kfree(buffer);
248         return r;
249 }
250
251 /* allocate private data */
252 static int ch341_attach(struct usb_serial *serial)
253 {
254         struct ch341_private *priv;
255         int r;
256
257         dbg("ch341_attach()");
258
259         /* private data */
260         priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
261         if (!priv)
262                 return -ENOMEM;
263
264         spin_lock_init(&priv->lock);
265         init_waitqueue_head(&priv->delta_msr_wait);
266         priv->baud_rate = DEFAULT_BAUD_RATE;
267         priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
268
269         r = ch341_configure(serial->dev, priv);
270         if (r < 0)
271                 goto error;
272
273         usb_set_serial_port_data(serial->port[0], priv);
274         return 0;
275
276 error:  kfree(priv);
277         return r;
278 }
279
280 static int ch341_carrier_raised(struct usb_serial_port *port)
281 {
282         struct ch341_private *priv = usb_get_serial_port_data(port);
283         if (priv->line_status & CH341_BIT_DCD)
284                 return 1;
285         return 0;
286 }
287
288 static void ch341_dtr_rts(struct usb_serial_port *port, int on)
289 {
290         struct ch341_private *priv = usb_get_serial_port_data(port);
291         unsigned long flags;
292
293         dbg("%s - port %d", __func__, port->number);
294         /* drop DTR and RTS */
295         spin_lock_irqsave(&priv->lock, flags);
296         if (on)
297                 priv->line_control |= CH341_BIT_RTS | CH341_BIT_DTR;
298         else
299                 priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
300         spin_unlock_irqrestore(&priv->lock, flags);
301         ch341_set_handshake(port->serial->dev, priv->line_control);
302         wake_up_interruptible(&priv->delta_msr_wait);
303 }
304
305 static void ch341_close(struct usb_serial_port *port)
306 {
307         dbg("%s - port %d", __func__, port->number);
308
309         usb_serial_generic_close(port);
310         usb_kill_urb(port->interrupt_in_urb);
311 }
312
313
314 /* open this device, set default parameters */
315 static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
316 {
317         struct usb_serial *serial = port->serial;
318         struct ch341_private *priv = usb_get_serial_port_data(serial->port[0]);
319         int r;
320
321         dbg("ch341_open()");
322
323         priv->baud_rate = DEFAULT_BAUD_RATE;
324
325         r = ch341_configure(serial->dev, priv);
326         if (r)
327                 goto out;
328
329         r = ch341_set_handshake(serial->dev, priv->line_control);
330         if (r)
331                 goto out;
332
333         r = ch341_set_baudrate(serial->dev, priv);
334         if (r)
335                 goto out;
336
337         dbg("%s - submitting interrupt urb", __func__);
338         port->interrupt_in_urb->dev = serial->dev;
339         r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
340         if (r) {
341                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
342                         " error %d\n", __func__, r);
343                 ch341_close(port);
344                 return -EPROTO;
345         }
346
347         r = usb_serial_generic_open(tty, port);
348
349 out:    return r;
350 }
351
352 /* Old_termios contains the original termios settings and
353  * tty->termios contains the new setting to be used.
354  */
355 static void ch341_set_termios(struct tty_struct *tty,
356                 struct usb_serial_port *port, struct ktermios *old_termios)
357 {
358         struct ch341_private *priv = usb_get_serial_port_data(port);
359         unsigned baud_rate;
360         unsigned long flags;
361
362         dbg("ch341_set_termios()");
363
364         baud_rate = tty_get_baud_rate(tty);
365
366         priv->baud_rate = baud_rate;
367
368         if (baud_rate) {
369                 spin_lock_irqsave(&priv->lock, flags);
370                 priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
371                 spin_unlock_irqrestore(&priv->lock, flags);
372                 ch341_set_baudrate(port->serial->dev, priv);
373         } else {
374                 spin_lock_irqsave(&priv->lock, flags);
375                 priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
376                 spin_unlock_irqrestore(&priv->lock, flags);
377         }
378
379         ch341_set_handshake(port->serial->dev, priv->line_control);
380
381         /* Unimplemented:
382          * (cflag & CSIZE) : data bits [5, 8]
383          * (cflag & PARENB) : parity {NONE, EVEN, ODD}
384          * (cflag & CSTOPB) : stop bits [1, 2]
385          */
386 }
387
388 static void ch341_break_ctl(struct tty_struct *tty, int break_state)
389 {
390         const uint16_t ch341_break_reg =
391                 CH341_REG_BREAK1 | ((uint16_t) CH341_REG_BREAK2 << 8);
392         struct usb_serial_port *port = tty->driver_data;
393         int r;
394         uint16_t reg_contents;
395         uint8_t *break_reg;
396
397         dbg("%s()", __func__);
398
399         break_reg = kmalloc(2, GFP_KERNEL);
400         if (!break_reg) {
401                 dev_err(&port->dev, "%s - kmalloc failed\n", __func__);
402                 return;
403         }
404
405         r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
406                         ch341_break_reg, 0, break_reg, 2);
407         if (r < 0) {
408                 dev_err(&port->dev, "%s - USB control read error (%d)\n",
409                                 __func__, r);
410                 goto out;
411         }
412         dbg("%s - initial ch341 break register contents - reg1: %x, reg2: %x",
413                         __func__, break_reg[0], break_reg[1]);
414         if (break_state != 0) {
415                 dbg("%s - Enter break state requested", __func__);
416                 break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
417                 break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
418         } else {
419                 dbg("%s - Leave break state requested", __func__);
420                 break_reg[0] |= CH341_NBREAK_BITS_REG1;
421                 break_reg[1] |= CH341_NBREAK_BITS_REG2;
422         }
423         dbg("%s - New ch341 break register contents - reg1: %x, reg2: %x",
424                         __func__, break_reg[0], break_reg[1]);
425         reg_contents = get_unaligned_le16(break_reg);
426         r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
427                         ch341_break_reg, reg_contents);
428         if (r < 0)
429                 dev_err(&port->dev, "%s - USB control write error (%d)\n",
430                                 __func__, r);
431 out:
432         kfree(break_reg);
433 }
434
435 static int ch341_tiocmset(struct tty_struct *tty, struct file *file,
436                           unsigned int set, unsigned int clear)
437 {
438         struct usb_serial_port *port = tty->driver_data;
439         struct ch341_private *priv = usb_get_serial_port_data(port);
440         unsigned long flags;
441         u8 control;
442
443         spin_lock_irqsave(&priv->lock, flags);
444         if (set & TIOCM_RTS)
445                 priv->line_control |= CH341_BIT_RTS;
446         if (set & TIOCM_DTR)
447                 priv->line_control |= CH341_BIT_DTR;
448         if (clear & TIOCM_RTS)
449                 priv->line_control &= ~CH341_BIT_RTS;
450         if (clear & TIOCM_DTR)
451                 priv->line_control &= ~CH341_BIT_DTR;
452         control = priv->line_control;
453         spin_unlock_irqrestore(&priv->lock, flags);
454
455         return ch341_set_handshake(port->serial->dev, control);
456 }
457
458 static void ch341_read_int_callback(struct urb *urb)
459 {
460         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
461         unsigned char *data = urb->transfer_buffer;
462         unsigned int actual_length = urb->actual_length;
463         int status;
464
465         dbg("%s (%d)", __func__, port->number);
466
467         switch (urb->status) {
468         case 0:
469                 /* success */
470                 break;
471         case -ECONNRESET:
472         case -ENOENT:
473         case -ESHUTDOWN:
474                 /* this urb is terminated, clean up */
475                 dbg("%s - urb shutting down with status: %d", __func__,
476                     urb->status);
477                 return;
478         default:
479                 dbg("%s - nonzero urb status received: %d", __func__,
480                     urb->status);
481                 goto exit;
482         }
483
484         usb_serial_debug_data(debug, &port->dev, __func__,
485                               urb->actual_length, urb->transfer_buffer);
486
487         if (actual_length >= 4) {
488                 struct ch341_private *priv = usb_get_serial_port_data(port);
489                 unsigned long flags;
490                 u8 prev_line_status = priv->line_status;
491
492                 spin_lock_irqsave(&priv->lock, flags);
493                 priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
494                 if ((data[1] & CH341_MULT_STAT))
495                         priv->multi_status_change = 1;
496                 spin_unlock_irqrestore(&priv->lock, flags);
497
498                 if ((priv->line_status ^ prev_line_status) & CH341_BIT_DCD) {
499                         struct tty_struct *tty = tty_port_tty_get(&port->port);
500                         if (tty)
501                                 usb_serial_handle_dcd_change(port, tty,
502                                             priv->line_status & CH341_BIT_DCD);
503                         tty_kref_put(tty);
504                 }
505
506                 wake_up_interruptible(&priv->delta_msr_wait);
507         }
508
509 exit:
510         status = usb_submit_urb(urb, GFP_ATOMIC);
511         if (status)
512                 dev_err(&urb->dev->dev,
513                         "%s - usb_submit_urb failed with result %d\n",
514                         __func__, status);
515 }
516
517 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
518 {
519         struct ch341_private *priv = usb_get_serial_port_data(port);
520         unsigned long flags;
521         u8 prevstatus;
522         u8 status;
523         u8 changed;
524         u8 multi_change = 0;
525
526         spin_lock_irqsave(&priv->lock, flags);
527         prevstatus = priv->line_status;
528         priv->multi_status_change = 0;
529         spin_unlock_irqrestore(&priv->lock, flags);
530
531         while (!multi_change) {
532                 interruptible_sleep_on(&priv->delta_msr_wait);
533                 /* see if a signal did it */
534                 if (signal_pending(current))
535                         return -ERESTARTSYS;
536
537                 spin_lock_irqsave(&priv->lock, flags);
538                 status = priv->line_status;
539                 multi_change = priv->multi_status_change;
540                 spin_unlock_irqrestore(&priv->lock, flags);
541
542                 changed = prevstatus ^ status;
543
544                 if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) ||
545                     ((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) ||
546                     ((arg & TIOCM_CD)  && (changed & CH341_BIT_DCD)) ||
547                     ((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {
548                         return 0;
549                 }
550                 prevstatus = status;
551         }
552
553         return 0;
554 }
555
556 /*static int ch341_ioctl(struct usb_serial_port *port, struct file *file,*/
557 static int ch341_ioctl(struct tty_struct *tty, struct file *file,
558                         unsigned int cmd, unsigned long arg)
559 {
560         struct usb_serial_port *port = tty->driver_data;
561         dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);
562
563         switch (cmd) {
564         case TIOCMIWAIT:
565                 dbg("%s (%d) TIOCMIWAIT", __func__,  port->number);
566                 return wait_modem_info(port, arg);
567
568         default:
569                 dbg("%s not supported = 0x%04x", __func__, cmd);
570                 break;
571         }
572
573         return -ENOIOCTLCMD;
574 }
575
576 static int ch341_tiocmget(struct tty_struct *tty, struct file *file)
577 {
578         struct usb_serial_port *port = tty->driver_data;
579         struct ch341_private *priv = usb_get_serial_port_data(port);
580         unsigned long flags;
581         u8 mcr;
582         u8 status;
583         unsigned int result;
584
585         dbg("%s (%d)", __func__, port->number);
586
587         spin_lock_irqsave(&priv->lock, flags);
588         mcr = priv->line_control;
589         status = priv->line_status;
590         spin_unlock_irqrestore(&priv->lock, flags);
591
592         result = ((mcr & CH341_BIT_DTR)         ? TIOCM_DTR : 0)
593                   | ((mcr & CH341_BIT_RTS)      ? TIOCM_RTS : 0)
594                   | ((status & CH341_BIT_CTS)   ? TIOCM_CTS : 0)
595                   | ((status & CH341_BIT_DSR)   ? TIOCM_DSR : 0)
596                   | ((status & CH341_BIT_RI)    ? TIOCM_RI  : 0)
597                   | ((status & CH341_BIT_DCD)   ? TIOCM_CD  : 0);
598
599         dbg("%s - result = %x", __func__, result);
600
601         return result;
602 }
603
604
605 static int ch341_reset_resume(struct usb_interface *intf)
606 {
607         struct usb_device *dev = interface_to_usbdev(intf);
608         struct usb_serial *serial = NULL;
609         struct ch341_private *priv;
610
611         serial = usb_get_intfdata(intf);
612         priv = usb_get_serial_port_data(serial->port[0]);
613
614         /*reconfigure ch341 serial port after bus-reset*/
615         ch341_configure(dev, priv);
616
617         usb_serial_resume(intf);
618
619         return 0;
620 }
621
622 static struct usb_driver ch341_driver = {
623         .name           = "ch341",
624         .probe          = usb_serial_probe,
625         .disconnect     = usb_serial_disconnect,
626         .suspend        = usb_serial_suspend,
627         .resume         = usb_serial_resume,
628         .reset_resume   = ch341_reset_resume,
629         .id_table       = id_table,
630         .no_dynamic_id  = 1,
631         .supports_autosuspend = 1,
632 };
633
634 static struct usb_serial_driver ch341_device = {
635         .driver = {
636                 .owner  = THIS_MODULE,
637                 .name   = "ch341-uart",
638         },
639         .id_table          = id_table,
640         .usb_driver        = &ch341_driver,
641         .num_ports         = 1,
642         .open              = ch341_open,
643         .dtr_rts           = ch341_dtr_rts,
644         .carrier_raised    = ch341_carrier_raised,
645         .close             = ch341_close,
646         .ioctl             = ch341_ioctl,
647         .set_termios       = ch341_set_termios,
648         .break_ctl         = ch341_break_ctl,
649         .tiocmget          = ch341_tiocmget,
650         .tiocmset          = ch341_tiocmset,
651         .read_int_callback = ch341_read_int_callback,
652         .attach            = ch341_attach,
653 };
654
655 static int __init ch341_init(void)
656 {
657         int retval;
658
659         retval = usb_serial_register(&ch341_device);
660         if (retval)
661                 return retval;
662         retval = usb_register(&ch341_driver);
663         if (retval)
664                 usb_serial_deregister(&ch341_device);
665         return retval;
666 }
667
668 static void __exit ch341_exit(void)
669 {
670         usb_deregister(&ch341_driver);
671         usb_serial_deregister(&ch341_device);
672 }
673
674 module_init(ch341_init);
675 module_exit(ch341_exit);
676 MODULE_LICENSE("GPL");
677
678 module_param(debug, bool, S_IRUGO | S_IWUSR);
679 MODULE_PARM_DESC(debug, "Debug enabled or not");
680
681 /* EOF ch341.c */