Merge tag 'pci-v5.11-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaa...
[platform/kernel/linux-rpi.git] / drivers / usb / serial / cypress_m8.c
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * USB Cypress M8 driver
4  *
5  *      Copyright (C) 2004
6  *          Lonnie Mendez (dignome@gmail.com)
7  *      Copyright (C) 2003,2004
8  *          Neil Whelchel (koyama@firstlight.net)
9  *
10  * See Documentation/usb/usb-serial.rst for more information on using this
11  * driver
12  *
13  * See http://geocities.com/i0xox0i for information on this driver and the
14  * earthmate usb device.
15  */
16
17 /* Thanks to Neil Whelchel for writing the first cypress m8 implementation
18    for linux. */
19 /* Thanks to cypress for providing references for the hid reports. */
20 /* Thanks to Jiang Zhang for providing links and for general help. */
21 /* Code originates and was built up from ftdi_sio, belkin, pl2303 and others.*/
22
23
24 #include <linux/kernel.h>
25 #include <linux/errno.h>
26 #include <linux/slab.h>
27 #include <linux/tty.h>
28 #include <linux/tty_driver.h>
29 #include <linux/tty_flip.h>
30 #include <linux/module.h>
31 #include <linux/moduleparam.h>
32 #include <linux/spinlock.h>
33 #include <linux/usb.h>
34 #include <linux/usb/serial.h>
35 #include <linux/serial.h>
36 #include <linux/kfifo.h>
37 #include <linux/delay.h>
38 #include <linux/uaccess.h>
39 #include <asm/unaligned.h>
40
41 #include "cypress_m8.h"
42
43
44 static bool stats;
45 static int interval;
46 static bool unstable_bauds;
47
48 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
49 #define DRIVER_DESC "Cypress USB to Serial Driver"
50
51 /* write buffer size defines */
52 #define CYPRESS_BUF_SIZE        1024
53
54 static const struct usb_device_id id_table_earthmate[] = {
55         { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
56         { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
57         { }                                             /* Terminating entry */
58 };
59
60 static const struct usb_device_id id_table_cyphidcomrs232[] = {
61         { USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
62         { USB_DEVICE(VENDOR_ID_SAI, PRODUCT_ID_CYPHIDCOM) },
63         { USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
64         { USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
65         { }                                             /* Terminating entry */
66 };
67
68 static const struct usb_device_id id_table_nokiaca42v2[] = {
69         { USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
70         { }                                             /* Terminating entry */
71 };
72
73 static const struct usb_device_id id_table_combined[] = {
74         { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
75         { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
76         { USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
77         { USB_DEVICE(VENDOR_ID_SAI, PRODUCT_ID_CYPHIDCOM) },
78         { USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
79         { USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
80         { USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
81         { }                                             /* Terminating entry */
82 };
83
84 MODULE_DEVICE_TABLE(usb, id_table_combined);
85
86 enum packet_format {
87         packet_format_1,  /* b0:status, b1:payload count */
88         packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
89 };
90
91 struct cypress_private {
92         spinlock_t lock;                   /* private lock */
93         int chiptype;                      /* identifier of device, for quirks/etc */
94         int bytes_in;                      /* used for statistics */
95         int bytes_out;                     /* used for statistics */
96         int cmd_count;                     /* used for statistics */
97         int cmd_ctrl;                      /* always set this to 1 before issuing a command */
98         struct kfifo write_fifo;           /* write fifo */
99         int write_urb_in_use;              /* write urb in use indicator */
100         int write_urb_interval;            /* interval to use for write urb */
101         int read_urb_interval;             /* interval to use for read urb */
102         int comm_is_ok;                    /* true if communication is (still) ok */
103         __u8 line_control;                 /* holds dtr / rts value */
104         __u8 current_status;               /* received from last read - info on dsr,cts,cd,ri,etc */
105         __u8 current_config;               /* stores the current configuration byte */
106         __u8 rx_flags;                     /* throttling - used from whiteheat/ftdi_sio */
107         enum packet_format pkt_fmt;        /* format to use for packet send / receive */
108         int get_cfg_unsafe;                /* If true, the CYPRESS_GET_CONFIG is unsafe */
109         int baud_rate;                     /* stores current baud rate in
110                                               integer form */
111         char prev_status;                  /* used for TIOCMIWAIT */
112 };
113
114 /* function prototypes for the Cypress USB to serial device */
115 static int  cypress_earthmate_port_probe(struct usb_serial_port *port);
116 static int  cypress_hidcom_port_probe(struct usb_serial_port *port);
117 static int  cypress_ca42v2_port_probe(struct usb_serial_port *port);
118 static int  cypress_port_remove(struct usb_serial_port *port);
119 static int  cypress_open(struct tty_struct *tty, struct usb_serial_port *port);
120 static void cypress_close(struct usb_serial_port *port);
121 static void cypress_dtr_rts(struct usb_serial_port *port, int on);
122 static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
123                         const unsigned char *buf, int count);
124 static void cypress_send(struct usb_serial_port *port);
125 static int  cypress_write_room(struct tty_struct *tty);
126 static void cypress_earthmate_init_termios(struct tty_struct *tty);
127 static void cypress_set_termios(struct tty_struct *tty,
128                         struct usb_serial_port *port, struct ktermios *old);
129 static int  cypress_tiocmget(struct tty_struct *tty);
130 static int  cypress_tiocmset(struct tty_struct *tty,
131                         unsigned int set, unsigned int clear);
132 static int  cypress_chars_in_buffer(struct tty_struct *tty);
133 static void cypress_throttle(struct tty_struct *tty);
134 static void cypress_unthrottle(struct tty_struct *tty);
135 static void cypress_set_dead(struct usb_serial_port *port);
136 static void cypress_read_int_callback(struct urb *urb);
137 static void cypress_write_int_callback(struct urb *urb);
138
139 static struct usb_serial_driver cypress_earthmate_device = {
140         .driver = {
141                 .owner =                THIS_MODULE,
142                 .name =                 "earthmate",
143         },
144         .description =                  "DeLorme Earthmate USB",
145         .id_table =                     id_table_earthmate,
146         .num_ports =                    1,
147         .port_probe =                   cypress_earthmate_port_probe,
148         .port_remove =                  cypress_port_remove,
149         .open =                         cypress_open,
150         .close =                        cypress_close,
151         .dtr_rts =                      cypress_dtr_rts,
152         .write =                        cypress_write,
153         .write_room =                   cypress_write_room,
154         .init_termios =                 cypress_earthmate_init_termios,
155         .set_termios =                  cypress_set_termios,
156         .tiocmget =                     cypress_tiocmget,
157         .tiocmset =                     cypress_tiocmset,
158         .tiocmiwait =                   usb_serial_generic_tiocmiwait,
159         .chars_in_buffer =              cypress_chars_in_buffer,
160         .throttle =                     cypress_throttle,
161         .unthrottle =                   cypress_unthrottle,
162         .read_int_callback =            cypress_read_int_callback,
163         .write_int_callback =           cypress_write_int_callback,
164 };
165
166 static struct usb_serial_driver cypress_hidcom_device = {
167         .driver = {
168                 .owner =                THIS_MODULE,
169                 .name =                 "cyphidcom",
170         },
171         .description =                  "HID->COM RS232 Adapter",
172         .id_table =                     id_table_cyphidcomrs232,
173         .num_ports =                    1,
174         .port_probe =                   cypress_hidcom_port_probe,
175         .port_remove =                  cypress_port_remove,
176         .open =                         cypress_open,
177         .close =                        cypress_close,
178         .dtr_rts =                      cypress_dtr_rts,
179         .write =                        cypress_write,
180         .write_room =                   cypress_write_room,
181         .set_termios =                  cypress_set_termios,
182         .tiocmget =                     cypress_tiocmget,
183         .tiocmset =                     cypress_tiocmset,
184         .tiocmiwait =                   usb_serial_generic_tiocmiwait,
185         .chars_in_buffer =              cypress_chars_in_buffer,
186         .throttle =                     cypress_throttle,
187         .unthrottle =                   cypress_unthrottle,
188         .read_int_callback =            cypress_read_int_callback,
189         .write_int_callback =           cypress_write_int_callback,
190 };
191
192 static struct usb_serial_driver cypress_ca42v2_device = {
193         .driver = {
194                 .owner =                THIS_MODULE,
195                 .name =                 "nokiaca42v2",
196         },
197         .description =                  "Nokia CA-42 V2 Adapter",
198         .id_table =                     id_table_nokiaca42v2,
199         .num_ports =                    1,
200         .port_probe =                   cypress_ca42v2_port_probe,
201         .port_remove =                  cypress_port_remove,
202         .open =                         cypress_open,
203         .close =                        cypress_close,
204         .dtr_rts =                      cypress_dtr_rts,
205         .write =                        cypress_write,
206         .write_room =                   cypress_write_room,
207         .set_termios =                  cypress_set_termios,
208         .tiocmget =                     cypress_tiocmget,
209         .tiocmset =                     cypress_tiocmset,
210         .tiocmiwait =                   usb_serial_generic_tiocmiwait,
211         .chars_in_buffer =              cypress_chars_in_buffer,
212         .throttle =                     cypress_throttle,
213         .unthrottle =                   cypress_unthrottle,
214         .read_int_callback =            cypress_read_int_callback,
215         .write_int_callback =           cypress_write_int_callback,
216 };
217
218 static struct usb_serial_driver * const serial_drivers[] = {
219         &cypress_earthmate_device, &cypress_hidcom_device,
220         &cypress_ca42v2_device, NULL
221 };
222
223 /*****************************************************************************
224  * Cypress serial helper functions
225  *****************************************************************************/
226
227 /* FRWD Dongle hidcom needs to skip reset and speed checks */
228 static inline bool is_frwd(struct usb_device *dev)
229 {
230         return ((le16_to_cpu(dev->descriptor.idVendor) == VENDOR_ID_FRWD) &&
231                 (le16_to_cpu(dev->descriptor.idProduct) == PRODUCT_ID_CYPHIDCOM_FRWD));
232 }
233
234 static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
235 {
236         struct cypress_private *priv;
237         priv = usb_get_serial_port_data(port);
238
239         if (unstable_bauds)
240                 return new_rate;
241
242         /* FRWD Dongle uses 115200 bps */
243         if (is_frwd(port->serial->dev))
244                 return new_rate;
245
246         /*
247          * The general purpose firmware for the Cypress M8 allows for
248          * a maximum speed of 57600bps (I have no idea whether DeLorme
249          * chose to use the general purpose firmware or not), if you
250          * need to modify this speed setting for your own project
251          * please add your own chiptype and modify the code likewise.
252          * The Cypress HID->COM device will work successfully up to
253          * 115200bps (but the actual throughput is around 3kBps).
254          */
255         if (port->serial->dev->speed == USB_SPEED_LOW) {
256                 /*
257                  * Mike Isely <isely@pobox.com> 2-Feb-2008: The
258                  * Cypress app note that describes this mechanism
259                  * states the the low-speed part can't handle more
260                  * than 800 bytes/sec, in which case 4800 baud is the
261                  * safest speed for a part like that.
262                  */
263                 if (new_rate > 4800) {
264                         dev_dbg(&port->dev,
265                                 "%s - failed setting baud rate, device incapable speed %d\n",
266                                 __func__, new_rate);
267                         return -1;
268                 }
269         }
270         switch (priv->chiptype) {
271         case CT_EARTHMATE:
272                 if (new_rate <= 600) {
273                         /* 300 and 600 baud rates are supported under
274                          * the generic firmware, but are not used with
275                          * NMEA and SiRF protocols */
276                         dev_dbg(&port->dev,
277                                 "%s - failed setting baud rate, unsupported speed of %d on Earthmate GPS\n",
278                                 __func__, new_rate);
279                         return -1;
280                 }
281                 break;
282         default:
283                 break;
284         }
285         return new_rate;
286 }
287
288
289 /* This function can either set or retrieve the current serial line settings */
290 static int cypress_serial_control(struct tty_struct *tty,
291         struct usb_serial_port *port, speed_t baud_rate, int data_bits,
292         int stop_bits, int parity_enable, int parity_type, int reset,
293         int cypress_request_type)
294 {
295         int new_baudrate = 0, retval = 0, tries = 0;
296         struct cypress_private *priv;
297         struct device *dev = &port->dev;
298         u8 *feature_buffer;
299         const unsigned int feature_len = 5;
300         unsigned long flags;
301
302         priv = usb_get_serial_port_data(port);
303
304         if (!priv->comm_is_ok)
305                 return -ENODEV;
306
307         feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
308         if (!feature_buffer)
309                 return -ENOMEM;
310
311         switch (cypress_request_type) {
312         case CYPRESS_SET_CONFIG:
313                 /* 0 means 'Hang up' so doesn't change the true bit rate */
314                 new_baudrate = priv->baud_rate;
315                 if (baud_rate && baud_rate != priv->baud_rate) {
316                         dev_dbg(dev, "%s - baud rate is changing\n", __func__);
317                         retval = analyze_baud_rate(port, baud_rate);
318                         if (retval >= 0) {
319                                 new_baudrate = retval;
320                                 dev_dbg(dev, "%s - New baud rate set to %d\n",
321                                         __func__, new_baudrate);
322                         }
323                 }
324                 dev_dbg(dev, "%s - baud rate is being sent as %d\n", __func__,
325                         new_baudrate);
326
327                 /* fill the feature_buffer with new configuration */
328                 put_unaligned_le32(new_baudrate, feature_buffer);
329                 feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
330                 /* 1 bit gap */
331                 feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
332                 feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
333                 feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
334                 /* 1 bit gap */
335                 feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
336
337                 dev_dbg(dev, "%s - device is being sent this feature report:\n", __func__);
338                 dev_dbg(dev, "%s - %02X - %02X - %02X - %02X - %02X\n", __func__,
339                         feature_buffer[0], feature_buffer[1],
340                         feature_buffer[2], feature_buffer[3],
341                         feature_buffer[4]);
342
343                 do {
344                         retval = usb_control_msg(port->serial->dev,
345                                         usb_sndctrlpipe(port->serial->dev, 0),
346                                         HID_REQ_SET_REPORT,
347                                         USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
348                                         0x0300, 0, feature_buffer,
349                                         feature_len, 500);
350
351                         if (tries++ >= 3)
352                                 break;
353
354                 } while (retval != feature_len &&
355                          retval != -ENODEV);
356
357                 if (retval != feature_len) {
358                         dev_err(dev, "%s - failed sending serial line settings - %d\n",
359                                 __func__, retval);
360                         cypress_set_dead(port);
361                 } else {
362                         spin_lock_irqsave(&priv->lock, flags);
363                         priv->baud_rate = new_baudrate;
364                         priv->current_config = feature_buffer[4];
365                         spin_unlock_irqrestore(&priv->lock, flags);
366                         /* If we asked for a speed change encode it */
367                         if (baud_rate)
368                                 tty_encode_baud_rate(tty,
369                                         new_baudrate, new_baudrate);
370                 }
371         break;
372         case CYPRESS_GET_CONFIG:
373                 if (priv->get_cfg_unsafe) {
374                         /* Not implemented for this device,
375                            and if we try to do it we're likely
376                            to crash the hardware. */
377                         retval = -ENOTTY;
378                         goto out;
379                 }
380                 dev_dbg(dev, "%s - retrieving serial line settings\n", __func__);
381                 do {
382                         retval = usb_control_msg(port->serial->dev,
383                                         usb_rcvctrlpipe(port->serial->dev, 0),
384                                         HID_REQ_GET_REPORT,
385                                         USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
386                                         0x0300, 0, feature_buffer,
387                                         feature_len, 500);
388
389                         if (tries++ >= 3)
390                                 break;
391                 } while (retval != feature_len
392                                                 && retval != -ENODEV);
393
394                 if (retval != feature_len) {
395                         dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
396                                 __func__, retval);
397                         cypress_set_dead(port);
398                         goto out;
399                 } else {
400                         spin_lock_irqsave(&priv->lock, flags);
401                         /* store the config in one byte, and later
402                            use bit masks to check values */
403                         priv->current_config = feature_buffer[4];
404                         priv->baud_rate = get_unaligned_le32(feature_buffer);
405                         spin_unlock_irqrestore(&priv->lock, flags);
406                 }
407         }
408         spin_lock_irqsave(&priv->lock, flags);
409         ++priv->cmd_count;
410         spin_unlock_irqrestore(&priv->lock, flags);
411 out:
412         kfree(feature_buffer);
413         return retval;
414 } /* cypress_serial_control */
415
416
417 static void cypress_set_dead(struct usb_serial_port *port)
418 {
419         struct cypress_private *priv = usb_get_serial_port_data(port);
420         unsigned long flags;
421
422         spin_lock_irqsave(&priv->lock, flags);
423         if (!priv->comm_is_ok) {
424                 spin_unlock_irqrestore(&priv->lock, flags);
425                 return;
426         }
427         priv->comm_is_ok = 0;
428         spin_unlock_irqrestore(&priv->lock, flags);
429
430         dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
431                 "interval might be too short\n", port->port_number);
432 }
433
434
435 /*****************************************************************************
436  * Cypress serial driver functions
437  *****************************************************************************/
438
439
440 static int cypress_generic_port_probe(struct usb_serial_port *port)
441 {
442         struct usb_serial *serial = port->serial;
443         struct cypress_private *priv;
444
445         if (!port->interrupt_out_urb || !port->interrupt_in_urb) {
446                 dev_err(&port->dev, "required endpoint is missing\n");
447                 return -ENODEV;
448         }
449
450         priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
451         if (!priv)
452                 return -ENOMEM;
453
454         priv->comm_is_ok = !0;
455         spin_lock_init(&priv->lock);
456         if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
457                 kfree(priv);
458                 return -ENOMEM;
459         }
460
461         /* Skip reset for FRWD device. It is a workaound:
462            device hangs if it receives SET_CONFIGURE in Configured
463            state. */
464         if (!is_frwd(serial->dev))
465                 usb_reset_configuration(serial->dev);
466
467         priv->cmd_ctrl = 0;
468         priv->line_control = 0;
469         priv->rx_flags = 0;
470         /* Default packet format setting is determined by packet size.
471            Anything with a size larger then 9 must have a separate
472            count field since the 3 bit count field is otherwise too
473            small.  Otherwise we can use the slightly more compact
474            format.  This is in accordance with the cypress_m8 serial
475            converter app note. */
476         if (port->interrupt_out_size > 9)
477                 priv->pkt_fmt = packet_format_1;
478         else
479                 priv->pkt_fmt = packet_format_2;
480
481         if (interval > 0) {
482                 priv->write_urb_interval = interval;
483                 priv->read_urb_interval = interval;
484                 dev_dbg(&port->dev, "%s - read & write intervals forced to %d\n",
485                         __func__, interval);
486         } else {
487                 priv->write_urb_interval = port->interrupt_out_urb->interval;
488                 priv->read_urb_interval = port->interrupt_in_urb->interval;
489                 dev_dbg(&port->dev, "%s - intervals: read=%d write=%d\n",
490                         __func__, priv->read_urb_interval,
491                         priv->write_urb_interval);
492         }
493         usb_set_serial_port_data(port, priv);
494
495         port->port.drain_delay = 256;
496
497         return 0;
498 }
499
500
501 static int cypress_earthmate_port_probe(struct usb_serial_port *port)
502 {
503         struct usb_serial *serial = port->serial;
504         struct cypress_private *priv;
505         int ret;
506
507         ret = cypress_generic_port_probe(port);
508         if (ret) {
509                 dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
510                 return ret;
511         }
512
513         priv = usb_get_serial_port_data(port);
514         priv->chiptype = CT_EARTHMATE;
515         /* All Earthmate devices use the separated-count packet
516            format!  Idiotic. */
517         priv->pkt_fmt = packet_format_1;
518         if (serial->dev->descriptor.idProduct !=
519                                 cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
520                 /* The old original USB Earthmate seemed able to
521                    handle GET_CONFIG requests; everything they've
522                    produced since that time crashes if this command is
523                    attempted :-( */
524                 dev_dbg(&port->dev,
525                         "%s - Marking this device as unsafe for GET_CONFIG commands\n",
526                         __func__);
527                 priv->get_cfg_unsafe = !0;
528         }
529
530         return 0;
531 }
532
533 static int cypress_hidcom_port_probe(struct usb_serial_port *port)
534 {
535         struct cypress_private *priv;
536         int ret;
537
538         ret = cypress_generic_port_probe(port);
539         if (ret) {
540                 dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
541                 return ret;
542         }
543
544         priv = usb_get_serial_port_data(port);
545         priv->chiptype = CT_CYPHIDCOM;
546
547         return 0;
548 }
549
550 static int cypress_ca42v2_port_probe(struct usb_serial_port *port)
551 {
552         struct cypress_private *priv;
553         int ret;
554
555         ret = cypress_generic_port_probe(port);
556         if (ret) {
557                 dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
558                 return ret;
559         }
560
561         priv = usb_get_serial_port_data(port);
562         priv->chiptype = CT_CA42V2;
563
564         return 0;
565 }
566
567 static int cypress_port_remove(struct usb_serial_port *port)
568 {
569         struct cypress_private *priv;
570
571         priv = usb_get_serial_port_data(port);
572
573         kfifo_free(&priv->write_fifo);
574         kfree(priv);
575
576         return 0;
577 }
578
579 static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
580 {
581         struct cypress_private *priv = usb_get_serial_port_data(port);
582         struct usb_serial *serial = port->serial;
583         unsigned long flags;
584         int result = 0;
585
586         if (!priv->comm_is_ok)
587                 return -EIO;
588
589         /* clear halts before open */
590         usb_clear_halt(serial->dev, 0x81);
591         usb_clear_halt(serial->dev, 0x02);
592
593         spin_lock_irqsave(&priv->lock, flags);
594         /* reset read/write statistics */
595         priv->bytes_in = 0;
596         priv->bytes_out = 0;
597         priv->cmd_count = 0;
598         priv->rx_flags = 0;
599         spin_unlock_irqrestore(&priv->lock, flags);
600
601         /* Set termios */
602         cypress_send(port);
603
604         if (tty)
605                 cypress_set_termios(tty, port, NULL);
606
607         /* setup the port and start reading from the device */
608         usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
609                 usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
610                 port->interrupt_in_urb->transfer_buffer,
611                 port->interrupt_in_urb->transfer_buffer_length,
612                 cypress_read_int_callback, port, priv->read_urb_interval);
613         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
614
615         if (result) {
616                 dev_err(&port->dev,
617                         "%s - failed submitting read urb, error %d\n",
618                                                         __func__, result);
619                 cypress_set_dead(port);
620         }
621
622         return result;
623 } /* cypress_open */
624
625 static void cypress_dtr_rts(struct usb_serial_port *port, int on)
626 {
627         struct cypress_private *priv = usb_get_serial_port_data(port);
628         /* drop dtr and rts */
629         spin_lock_irq(&priv->lock);
630         if (on == 0)
631                 priv->line_control = 0;
632         else 
633                 priv->line_control = CONTROL_DTR | CONTROL_RTS;
634         priv->cmd_ctrl = 1;
635         spin_unlock_irq(&priv->lock);
636         cypress_write(NULL, port, NULL, 0);
637 }
638
639 static void cypress_close(struct usb_serial_port *port)
640 {
641         struct cypress_private *priv = usb_get_serial_port_data(port);
642         unsigned long flags;
643
644         spin_lock_irqsave(&priv->lock, flags);
645         kfifo_reset_out(&priv->write_fifo);
646         spin_unlock_irqrestore(&priv->lock, flags);
647
648         dev_dbg(&port->dev, "%s - stopping urbs\n", __func__);
649         usb_kill_urb(port->interrupt_in_urb);
650         usb_kill_urb(port->interrupt_out_urb);
651
652         if (stats)
653                 dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
654                         priv->bytes_in, priv->bytes_out, priv->cmd_count);
655 } /* cypress_close */
656
657
658 static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
659                                         const unsigned char *buf, int count)
660 {
661         struct cypress_private *priv = usb_get_serial_port_data(port);
662
663         dev_dbg(&port->dev, "%s - %d bytes\n", __func__, count);
664
665         /* line control commands, which need to be executed immediately,
666            are not put into the buffer for obvious reasons.
667          */
668         if (priv->cmd_ctrl) {
669                 count = 0;
670                 goto finish;
671         }
672
673         if (!count)
674                 return count;
675
676         count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
677
678 finish:
679         cypress_send(port);
680
681         return count;
682 } /* cypress_write */
683
684
685 static void cypress_send(struct usb_serial_port *port)
686 {
687         int count = 0, result, offset, actual_size;
688         struct cypress_private *priv = usb_get_serial_port_data(port);
689         struct device *dev = &port->dev;
690         unsigned long flags;
691
692         if (!priv->comm_is_ok)
693                 return;
694
695         dev_dbg(dev, "%s - interrupt out size is %d\n", __func__,
696                 port->interrupt_out_size);
697
698         spin_lock_irqsave(&priv->lock, flags);
699         if (priv->write_urb_in_use) {
700                 dev_dbg(dev, "%s - can't write, urb in use\n", __func__);
701                 spin_unlock_irqrestore(&priv->lock, flags);
702                 return;
703         }
704         spin_unlock_irqrestore(&priv->lock, flags);
705
706         /* clear buffer */
707         memset(port->interrupt_out_urb->transfer_buffer, 0,
708                                                 port->interrupt_out_size);
709
710         spin_lock_irqsave(&priv->lock, flags);
711         switch (priv->pkt_fmt) {
712         default:
713         case packet_format_1:
714                 /* this is for the CY7C64013... */
715                 offset = 2;
716                 port->interrupt_out_buffer[0] = priv->line_control;
717                 break;
718         case packet_format_2:
719                 /* this is for the CY7C63743... */
720                 offset = 1;
721                 port->interrupt_out_buffer[0] = priv->line_control;
722                 break;
723         }
724
725         if (priv->line_control & CONTROL_RESET)
726                 priv->line_control &= ~CONTROL_RESET;
727
728         if (priv->cmd_ctrl) {
729                 priv->cmd_count++;
730                 dev_dbg(dev, "%s - line control command being issued\n", __func__);
731                 spin_unlock_irqrestore(&priv->lock, flags);
732                 goto send;
733         } else
734                 spin_unlock_irqrestore(&priv->lock, flags);
735
736         count = kfifo_out_locked(&priv->write_fifo,
737                                         &port->interrupt_out_buffer[offset],
738                                         port->interrupt_out_size - offset,
739                                         &priv->lock);
740         if (count == 0)
741                 return;
742
743         switch (priv->pkt_fmt) {
744         default:
745         case packet_format_1:
746                 port->interrupt_out_buffer[1] = count;
747                 break;
748         case packet_format_2:
749                 port->interrupt_out_buffer[0] |= count;
750         }
751
752         dev_dbg(dev, "%s - count is %d\n", __func__, count);
753
754 send:
755         spin_lock_irqsave(&priv->lock, flags);
756         priv->write_urb_in_use = 1;
757         spin_unlock_irqrestore(&priv->lock, flags);
758
759         if (priv->cmd_ctrl)
760                 actual_size = 1;
761         else
762                 actual_size = count +
763                               (priv->pkt_fmt == packet_format_1 ? 2 : 1);
764
765         usb_serial_debug_data(dev, __func__, port->interrupt_out_size,
766                               port->interrupt_out_urb->transfer_buffer);
767
768         usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
769                 usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
770                 port->interrupt_out_buffer, actual_size,
771                 cypress_write_int_callback, port, priv->write_urb_interval);
772         result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
773         if (result) {
774                 dev_err_console(port,
775                                 "%s - failed submitting write urb, error %d\n",
776                                                         __func__, result);
777                 priv->write_urb_in_use = 0;
778                 cypress_set_dead(port);
779         }
780
781         spin_lock_irqsave(&priv->lock, flags);
782         if (priv->cmd_ctrl)
783                 priv->cmd_ctrl = 0;
784
785         /* do not count the line control and size bytes */
786         priv->bytes_out += count;
787         spin_unlock_irqrestore(&priv->lock, flags);
788
789         usb_serial_port_softint(port);
790 } /* cypress_send */
791
792
793 /* returns how much space is available in the soft buffer */
794 static int cypress_write_room(struct tty_struct *tty)
795 {
796         struct usb_serial_port *port = tty->driver_data;
797         struct cypress_private *priv = usb_get_serial_port_data(port);
798         int room = 0;
799         unsigned long flags;
800
801         spin_lock_irqsave(&priv->lock, flags);
802         room = kfifo_avail(&priv->write_fifo);
803         spin_unlock_irqrestore(&priv->lock, flags);
804
805         dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
806         return room;
807 }
808
809
810 static int cypress_tiocmget(struct tty_struct *tty)
811 {
812         struct usb_serial_port *port = tty->driver_data;
813         struct cypress_private *priv = usb_get_serial_port_data(port);
814         __u8 status, control;
815         unsigned int result = 0;
816         unsigned long flags;
817
818         spin_lock_irqsave(&priv->lock, flags);
819         control = priv->line_control;
820         status = priv->current_status;
821         spin_unlock_irqrestore(&priv->lock, flags);
822
823         result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
824                 | ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
825                 | ((status & UART_CTS)        ? TIOCM_CTS : 0)
826                 | ((status & UART_DSR)        ? TIOCM_DSR : 0)
827                 | ((status & UART_RI)         ? TIOCM_RI  : 0)
828                 | ((status & UART_CD)         ? TIOCM_CD  : 0);
829
830         dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
831
832         return result;
833 }
834
835
836 static int cypress_tiocmset(struct tty_struct *tty,
837                                unsigned int set, unsigned int clear)
838 {
839         struct usb_serial_port *port = tty->driver_data;
840         struct cypress_private *priv = usb_get_serial_port_data(port);
841         unsigned long flags;
842
843         spin_lock_irqsave(&priv->lock, flags);
844         if (set & TIOCM_RTS)
845                 priv->line_control |= CONTROL_RTS;
846         if (set & TIOCM_DTR)
847                 priv->line_control |= CONTROL_DTR;
848         if (clear & TIOCM_RTS)
849                 priv->line_control &= ~CONTROL_RTS;
850         if (clear & TIOCM_DTR)
851                 priv->line_control &= ~CONTROL_DTR;
852         priv->cmd_ctrl = 1;
853         spin_unlock_irqrestore(&priv->lock, flags);
854
855         return cypress_write(tty, port, NULL, 0);
856 }
857
858 static void cypress_earthmate_init_termios(struct tty_struct *tty)
859 {
860         tty_encode_baud_rate(tty, 4800, 4800);
861 }
862
863 static void cypress_set_termios(struct tty_struct *tty,
864         struct usb_serial_port *port, struct ktermios *old_termios)
865 {
866         struct cypress_private *priv = usb_get_serial_port_data(port);
867         struct device *dev = &port->dev;
868         int data_bits, stop_bits, parity_type, parity_enable;
869         unsigned int cflag;
870         unsigned long flags;
871         __u8 oldlines;
872         int linechange = 0;
873
874         /* Unsupported features need clearing */
875         tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
876
877         cflag = tty->termios.c_cflag;
878
879         /* set number of data bits, parity, stop bits */
880         /* when parity is disabled the parity type bit is ignored */
881
882         /* 1 means 2 stop bits, 0 means 1 stop bit */
883         stop_bits = cflag & CSTOPB ? 1 : 0;
884
885         if (cflag & PARENB) {
886                 parity_enable = 1;
887                 /* 1 means odd parity, 0 means even parity */
888                 parity_type = cflag & PARODD ? 1 : 0;
889         } else
890                 parity_enable = parity_type = 0;
891
892         switch (cflag & CSIZE) {
893         case CS5:
894                 data_bits = 0;
895                 break;
896         case CS6:
897                 data_bits = 1;
898                 break;
899         case CS7:
900                 data_bits = 2;
901                 break;
902         case CS8:
903                 data_bits = 3;
904                 break;
905         default:
906                 dev_err(dev, "%s - CSIZE was set, but not CS5-CS8\n", __func__);
907                 data_bits = 3;
908         }
909         spin_lock_irqsave(&priv->lock, flags);
910         oldlines = priv->line_control;
911         if ((cflag & CBAUD) == B0) {
912                 /* drop dtr and rts */
913                 dev_dbg(dev, "%s - dropping the lines, baud rate 0bps\n", __func__);
914                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
915         } else
916                 priv->line_control = (CONTROL_DTR | CONTROL_RTS);
917         spin_unlock_irqrestore(&priv->lock, flags);
918
919         dev_dbg(dev, "%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)\n",
920                 __func__, stop_bits, parity_enable, parity_type, data_bits);
921
922         cypress_serial_control(tty, port, tty_get_baud_rate(tty),
923                         data_bits, stop_bits,
924                         parity_enable, parity_type,
925                         0, CYPRESS_SET_CONFIG);
926
927         /* we perform a CYPRESS_GET_CONFIG so that the current settings are
928          * filled into the private structure this should confirm that all is
929          * working if it returns what we just set */
930         cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
931
932         /* Here we can define custom tty settings for devices; the main tty
933          * termios flag base comes from empeg.c */
934
935         spin_lock_irqsave(&priv->lock, flags);
936         if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
937                 dev_dbg(dev, "Using custom termios settings for a baud rate of 4800bps.\n");
938                 /* define custom termios settings for NMEA protocol */
939
940                 tty->termios.c_iflag /* input modes - */
941                         &= ~(IGNBRK  /* disable ignore break */
942                         | BRKINT     /* disable break causes interrupt */
943                         | PARMRK     /* disable mark parity errors */
944                         | ISTRIP     /* disable clear high bit of input char */
945                         | INLCR      /* disable translate NL to CR */
946                         | IGNCR      /* disable ignore CR */
947                         | ICRNL      /* disable translate CR to NL */
948                         | IXON);     /* disable enable XON/XOFF flow control */
949
950                 tty->termios.c_oflag /* output modes */
951                         &= ~OPOST;    /* disable postprocess output char */
952
953                 tty->termios.c_lflag /* line discipline modes */
954                         &= ~(ECHO     /* disable echo input characters */
955                         | ECHONL      /* disable echo new line */
956                         | ICANON      /* disable erase, kill, werase, and rprnt
957                                          special characters */
958                         | ISIG        /* disable interrupt, quit, and suspend
959                                          special characters */
960                         | IEXTEN);    /* disable non-POSIX special characters */
961         } /* CT_CYPHIDCOM: Application should handle this for device */
962
963         linechange = (priv->line_control != oldlines);
964         spin_unlock_irqrestore(&priv->lock, flags);
965
966         /* if necessary, set lines */
967         if (linechange) {
968                 priv->cmd_ctrl = 1;
969                 cypress_write(tty, port, NULL, 0);
970         }
971 } /* cypress_set_termios */
972
973
974 /* returns amount of data still left in soft buffer */
975 static int cypress_chars_in_buffer(struct tty_struct *tty)
976 {
977         struct usb_serial_port *port = tty->driver_data;
978         struct cypress_private *priv = usb_get_serial_port_data(port);
979         int chars = 0;
980         unsigned long flags;
981
982         spin_lock_irqsave(&priv->lock, flags);
983         chars = kfifo_len(&priv->write_fifo);
984         spin_unlock_irqrestore(&priv->lock, flags);
985
986         dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
987         return chars;
988 }
989
990
991 static void cypress_throttle(struct tty_struct *tty)
992 {
993         struct usb_serial_port *port = tty->driver_data;
994         struct cypress_private *priv = usb_get_serial_port_data(port);
995
996         spin_lock_irq(&priv->lock);
997         priv->rx_flags = THROTTLED;
998         spin_unlock_irq(&priv->lock);
999 }
1000
1001
1002 static void cypress_unthrottle(struct tty_struct *tty)
1003 {
1004         struct usb_serial_port *port = tty->driver_data;
1005         struct cypress_private *priv = usb_get_serial_port_data(port);
1006         int actually_throttled, result;
1007
1008         spin_lock_irq(&priv->lock);
1009         actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1010         priv->rx_flags = 0;
1011         spin_unlock_irq(&priv->lock);
1012
1013         if (!priv->comm_is_ok)
1014                 return;
1015
1016         if (actually_throttled) {
1017                 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1018                 if (result) {
1019                         dev_err(&port->dev, "%s - failed submitting read urb, "
1020                                         "error %d\n", __func__, result);
1021                         cypress_set_dead(port);
1022                 }
1023         }
1024 }
1025
1026
1027 static void cypress_read_int_callback(struct urb *urb)
1028 {
1029         struct usb_serial_port *port = urb->context;
1030         struct cypress_private *priv = usb_get_serial_port_data(port);
1031         struct device *dev = &urb->dev->dev;
1032         struct tty_struct *tty;
1033         unsigned char *data = urb->transfer_buffer;
1034         unsigned long flags;
1035         char tty_flag = TTY_NORMAL;
1036         int bytes = 0;
1037         int result;
1038         int i = 0;
1039         int status = urb->status;
1040
1041         switch (status) {
1042         case 0: /* success */
1043                 break;
1044         case -ECONNRESET:
1045         case -ENOENT:
1046         case -ESHUTDOWN:
1047                 /* precursor to disconnect so just go away */
1048                 return;
1049         case -EPIPE:
1050                 /* Can't call usb_clear_halt while in_interrupt */
1051                 fallthrough;
1052         default:
1053                 /* something ugly is going on... */
1054                 dev_err(dev, "%s - unexpected nonzero read status received: %d\n",
1055                         __func__, status);
1056                 cypress_set_dead(port);
1057                 return;
1058         }
1059
1060         spin_lock_irqsave(&priv->lock, flags);
1061         if (priv->rx_flags & THROTTLED) {
1062                 dev_dbg(dev, "%s - now throttling\n", __func__);
1063                 priv->rx_flags |= ACTUALLY_THROTTLED;
1064                 spin_unlock_irqrestore(&priv->lock, flags);
1065                 return;
1066         }
1067         spin_unlock_irqrestore(&priv->lock, flags);
1068
1069         tty = tty_port_tty_get(&port->port);
1070         if (!tty) {
1071                 dev_dbg(dev, "%s - bad tty pointer - exiting\n", __func__);
1072                 return;
1073         }
1074
1075         spin_lock_irqsave(&priv->lock, flags);
1076         result = urb->actual_length;
1077         switch (priv->pkt_fmt) {
1078         default:
1079         case packet_format_1:
1080                 /* This is for the CY7C64013... */
1081                 priv->current_status = data[0] & 0xF8;
1082                 bytes = data[1] + 2;
1083                 i = 2;
1084                 break;
1085         case packet_format_2:
1086                 /* This is for the CY7C63743... */
1087                 priv->current_status = data[0] & 0xF8;
1088                 bytes = (data[0] & 0x07) + 1;
1089                 i = 1;
1090                 break;
1091         }
1092         spin_unlock_irqrestore(&priv->lock, flags);
1093         if (result < bytes) {
1094                 dev_dbg(dev,
1095                         "%s - wrong packet size - received %d bytes but packet said %d bytes\n",
1096                         __func__, result, bytes);
1097                 goto continue_read;
1098         }
1099
1100         usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1101
1102         spin_lock_irqsave(&priv->lock, flags);
1103         /* check to see if status has changed */
1104         if (priv->current_status != priv->prev_status) {
1105                 u8 delta = priv->current_status ^ priv->prev_status;
1106
1107                 if (delta & UART_MSR_MASK) {
1108                         if (delta & UART_CTS)
1109                                 port->icount.cts++;
1110                         if (delta & UART_DSR)
1111                                 port->icount.dsr++;
1112                         if (delta & UART_RI)
1113                                 port->icount.rng++;
1114                         if (delta & UART_CD)
1115                                 port->icount.dcd++;
1116
1117                         wake_up_interruptible(&port->port.delta_msr_wait);
1118                 }
1119
1120                 priv->prev_status = priv->current_status;
1121         }
1122         spin_unlock_irqrestore(&priv->lock, flags);
1123
1124         /* hangup, as defined in acm.c... this might be a bad place for it
1125          * though */
1126         if (tty && !C_CLOCAL(tty) && !(priv->current_status & UART_CD)) {
1127                 dev_dbg(dev, "%s - calling hangup\n", __func__);
1128                 tty_hangup(tty);
1129                 goto continue_read;
1130         }
1131
1132         /* There is one error bit... I'm assuming it is a parity error
1133          * indicator as the generic firmware will set this bit to 1 if a
1134          * parity error occurs.
1135          * I can not find reference to any other error events. */
1136         spin_lock_irqsave(&priv->lock, flags);
1137         if (priv->current_status & CYP_ERROR) {
1138                 spin_unlock_irqrestore(&priv->lock, flags);
1139                 tty_flag = TTY_PARITY;
1140                 dev_dbg(dev, "%s - Parity Error detected\n", __func__);
1141         } else
1142                 spin_unlock_irqrestore(&priv->lock, flags);
1143
1144         /* process read if there is data other than line status */
1145         if (bytes > i) {
1146                 tty_insert_flip_string_fixed_flag(&port->port, data + i,
1147                                 tty_flag, bytes - i);
1148                 tty_flip_buffer_push(&port->port);
1149         }
1150
1151         spin_lock_irqsave(&priv->lock, flags);
1152         /* control and status byte(s) are also counted */
1153         priv->bytes_in += bytes;
1154         spin_unlock_irqrestore(&priv->lock, flags);
1155
1156 continue_read:
1157         tty_kref_put(tty);
1158
1159         /* Continue trying to always read */
1160
1161         if (priv->comm_is_ok) {
1162                 usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1163                                 usb_rcvintpipe(port->serial->dev,
1164                                         port->interrupt_in_endpointAddress),
1165                                 port->interrupt_in_urb->transfer_buffer,
1166                                 port->interrupt_in_urb->transfer_buffer_length,
1167                                 cypress_read_int_callback, port,
1168                                 priv->read_urb_interval);
1169                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1170                 if (result && result != -EPERM) {
1171                         dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
1172                                 __func__, result);
1173                         cypress_set_dead(port);
1174                 }
1175         }
1176 } /* cypress_read_int_callback */
1177
1178
1179 static void cypress_write_int_callback(struct urb *urb)
1180 {
1181         struct usb_serial_port *port = urb->context;
1182         struct cypress_private *priv = usb_get_serial_port_data(port);
1183         struct device *dev = &urb->dev->dev;
1184         int status = urb->status;
1185
1186         switch (status) {
1187         case 0:
1188                 /* success */
1189                 break;
1190         case -ECONNRESET:
1191         case -ENOENT:
1192         case -ESHUTDOWN:
1193                 /* this urb is terminated, clean up */
1194                 dev_dbg(dev, "%s - urb shutting down with status: %d\n",
1195                         __func__, status);
1196                 priv->write_urb_in_use = 0;
1197                 return;
1198         case -EPIPE:
1199                 /* Cannot call usb_clear_halt while in_interrupt */
1200                 fallthrough;
1201         default:
1202                 dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
1203                         __func__, status);
1204                 cypress_set_dead(port);
1205                 break;
1206         }
1207         priv->write_urb_in_use = 0;
1208
1209         /* send any buffered data */
1210         cypress_send(port);
1211 }
1212
1213 module_usb_serial_driver(serial_drivers, id_table_combined);
1214
1215 MODULE_AUTHOR(DRIVER_AUTHOR);
1216 MODULE_DESCRIPTION(DRIVER_DESC);
1217 MODULE_LICENSE("GPL");
1218
1219 module_param(stats, bool, S_IRUGO | S_IWUSR);
1220 MODULE_PARM_DESC(stats, "Enable statistics or not");
1221 module_param(interval, int, S_IRUGO | S_IWUSR);
1222 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1223 module_param(unstable_bauds, bool, S_IRUGO | S_IWUSR);
1224 MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");