xfrm: SAD entries do not expire correctly after suspend-resume
[linux-2.6.git] / drivers / net / can / usb / ems_usb.c
1 /*
2  * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
3  *
4  * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published
8  * by the Free Software Foundation; version 2 of the License.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License along
16  * with this program; if not, write to the Free Software Foundation, Inc.,
17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18  */
19 #include <linux/init.h>
20 #include <linux/signal.h>
21 #include <linux/slab.h>
22 #include <linux/module.h>
23 #include <linux/netdevice.h>
24 #include <linux/usb.h>
25
26 #include <linux/can.h>
27 #include <linux/can/dev.h>
28 #include <linux/can/error.h>
29
30 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
31 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
32 MODULE_LICENSE("GPL v2");
33
34 /* Control-Values for CPC_Control() Command Subject Selection */
35 #define CONTR_CAN_MESSAGE 0x04
36 #define CONTR_CAN_STATE   0x0C
37 #define CONTR_BUS_ERROR   0x1C
38
39 /* Control Command Actions */
40 #define CONTR_CONT_OFF 0
41 #define CONTR_CONT_ON  1
42 #define CONTR_ONCE     2
43
44 /* Messages from CPC to PC */
45 #define CPC_MSG_TYPE_CAN_FRAME       1  /* CAN data frame */
46 #define CPC_MSG_TYPE_RTR_FRAME       8  /* CAN remote frame */
47 #define CPC_MSG_TYPE_CAN_PARAMS      12 /* Actual CAN parameters */
48 #define CPC_MSG_TYPE_CAN_STATE       14 /* CAN state message */
49 #define CPC_MSG_TYPE_EXT_CAN_FRAME   16 /* Extended CAN data frame */
50 #define CPC_MSG_TYPE_EXT_RTR_FRAME   17 /* Extended remote frame */
51 #define CPC_MSG_TYPE_CONTROL         19 /* change interface behavior */
52 #define CPC_MSG_TYPE_CONFIRM         20 /* command processed confirmation */
53 #define CPC_MSG_TYPE_OVERRUN         21 /* overrun events */
54 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
55 #define CPC_MSG_TYPE_ERR_COUNTER     25 /* RX/TX error counter */
56
57 /* Messages from the PC to the CPC interface  */
58 #define CPC_CMD_TYPE_CAN_FRAME     1   /* CAN data frame */
59 #define CPC_CMD_TYPE_CONTROL       3   /* control of interface behavior */
60 #define CPC_CMD_TYPE_CAN_PARAMS    6   /* set CAN parameters */
61 #define CPC_CMD_TYPE_RTR_FRAME     13  /* CAN remote frame */
62 #define CPC_CMD_TYPE_CAN_STATE     14  /* CAN state message */
63 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15  /* Extended CAN data frame */
64 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16  /* Extended CAN remote frame */
65 #define CPC_CMD_TYPE_CAN_EXIT      200 /* exit the CAN */
66
67 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
68 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8  /* clear CPC_MSG queue */
69 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
70
71 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
72
73 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
74
75 /* Overrun types */
76 #define CPC_OVR_EVENT_CAN       0x01
77 #define CPC_OVR_EVENT_CANSTATE  0x02
78 #define CPC_OVR_EVENT_BUSERROR  0x04
79
80 /*
81  * If the CAN controller lost a message we indicate it with the highest bit
82  * set in the count field.
83  */
84 #define CPC_OVR_HW 0x80
85
86 /* Size of the "struct ems_cpc_msg" without the union */
87 #define CPC_MSG_HEADER_LEN   11
88 #define CPC_CAN_MSG_MIN_SIZE 5
89
90 /* Define these values to match your devices */
91 #define USB_CPCUSB_VENDOR_ID 0x12D6
92
93 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
94
95 /* Mode register NXP LPC2119/SJA1000 CAN Controller */
96 #define SJA1000_MOD_NORMAL 0x00
97 #define SJA1000_MOD_RM     0x01
98
99 /* ECC register NXP LPC2119/SJA1000 CAN Controller */
100 #define SJA1000_ECC_SEG   0x1F
101 #define SJA1000_ECC_DIR   0x20
102 #define SJA1000_ECC_ERR   0x06
103 #define SJA1000_ECC_BIT   0x00
104 #define SJA1000_ECC_FORM  0x40
105 #define SJA1000_ECC_STUFF 0x80
106 #define SJA1000_ECC_MASK  0xc0
107
108 /* Status register content */
109 #define SJA1000_SR_BS 0x80
110 #define SJA1000_SR_ES 0x40
111
112 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
113
114 /*
115  * The device actually uses a 16MHz clock to generate the CAN clock
116  * but it expects SJA1000 bit settings based on 8MHz (is internally
117  * converted).
118  */
119 #define EMS_USB_ARM7_CLOCK 8000000
120
121 /*
122  * CAN-Message representation in a CPC_MSG. Message object type is
123  * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
124  * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
125  */
126 struct cpc_can_msg {
127         u32 id;
128         u8 length;
129         u8 msg[8];
130 };
131
132 /* Representation of the CAN parameters for the SJA1000 controller */
133 struct cpc_sja1000_params {
134         u8 mode;
135         u8 acc_code0;
136         u8 acc_code1;
137         u8 acc_code2;
138         u8 acc_code3;
139         u8 acc_mask0;
140         u8 acc_mask1;
141         u8 acc_mask2;
142         u8 acc_mask3;
143         u8 btr0;
144         u8 btr1;
145         u8 outp_contr;
146 };
147
148 /* CAN params message representation */
149 struct cpc_can_params {
150         u8 cc_type;
151
152         /* Will support M16C CAN controller in the future */
153         union {
154                 struct cpc_sja1000_params sja1000;
155         } cc_params;
156 };
157
158 /* Structure for confirmed message handling */
159 struct cpc_confirm {
160         u8 error; /* error code */
161 };
162
163 /* Structure for overrun conditions */
164 struct cpc_overrun {
165         u8 event;
166         u8 count;
167 };
168
169 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
170 struct cpc_sja1000_can_error {
171         u8 ecc;
172         u8 rxerr;
173         u8 txerr;
174 };
175
176 /* structure for CAN error conditions */
177 struct cpc_can_error {
178         u8 ecode;
179
180         struct {
181                 u8 cc_type;
182
183                 /* Other controllers may also provide error code capture regs */
184                 union {
185                         struct cpc_sja1000_can_error sja1000;
186                 } regs;
187         } cc;
188 };
189
190 /*
191  * Structure containing RX/TX error counter. This structure is used to request
192  * the values of the CAN controllers TX and RX error counter.
193  */
194 struct cpc_can_err_counter {
195         u8 rx;
196         u8 tx;
197 };
198
199 /* Main message type used between library and application */
200 struct __attribute__ ((packed)) ems_cpc_msg {
201         u8 type;        /* type of message */
202         u8 length;      /* length of data within union 'msg' */
203         u8 msgid;       /* confirmation handle */
204         u32 ts_sec;     /* timestamp in seconds */
205         u32 ts_nsec;    /* timestamp in nano seconds */
206
207         union {
208                 u8 generic[64];
209                 struct cpc_can_msg can_msg;
210                 struct cpc_can_params can_params;
211                 struct cpc_confirm confirmation;
212                 struct cpc_overrun overrun;
213                 struct cpc_can_error error;
214                 struct cpc_can_err_counter err_counter;
215                 u8 can_state;
216         } msg;
217 };
218
219 /*
220  * Table of devices that work with this driver
221  * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
222  */
223 static struct usb_device_id ems_usb_table[] = {
224         {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
225         {} /* Terminating entry */
226 };
227
228 MODULE_DEVICE_TABLE(usb, ems_usb_table);
229
230 #define RX_BUFFER_SIZE      64
231 #define CPC_HEADER_SIZE     4
232 #define INTR_IN_BUFFER_SIZE 4
233
234 #define MAX_RX_URBS 10
235 #define MAX_TX_URBS 10
236
237 struct ems_usb;
238
239 struct ems_tx_urb_context {
240         struct ems_usb *dev;
241
242         u32 echo_index;
243         u8 dlc;
244 };
245
246 struct ems_usb {
247         struct can_priv can; /* must be the first member */
248         int open_time;
249
250         struct sk_buff *echo_skb[MAX_TX_URBS];
251
252         struct usb_device *udev;
253         struct net_device *netdev;
254
255         atomic_t active_tx_urbs;
256         struct usb_anchor tx_submitted;
257         struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
258
259         struct usb_anchor rx_submitted;
260
261         struct urb *intr_urb;
262
263         u8 *tx_msg_buffer;
264
265         u8 *intr_in_buffer;
266         unsigned int free_slots; /* remember number of available slots */
267
268         struct ems_cpc_msg active_params; /* active controller parameters */
269 };
270
271 static void ems_usb_read_interrupt_callback(struct urb *urb)
272 {
273         struct ems_usb *dev = urb->context;
274         struct net_device *netdev = dev->netdev;
275         int err;
276
277         if (!netif_device_present(netdev))
278                 return;
279
280         switch (urb->status) {
281         case 0:
282                 dev->free_slots = dev->intr_in_buffer[1];
283                 break;
284
285         case -ECONNRESET: /* unlink */
286         case -ENOENT:
287         case -ESHUTDOWN:
288                 return;
289
290         default:
291                 dev_info(netdev->dev.parent, "Rx interrupt aborted %d\n",
292                          urb->status);
293                 break;
294         }
295
296         err = usb_submit_urb(urb, GFP_ATOMIC);
297
298         if (err == -ENODEV)
299                 netif_device_detach(netdev);
300         else if (err)
301                 dev_err(netdev->dev.parent,
302                         "failed resubmitting intr urb: %d\n", err);
303
304         return;
305 }
306
307 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
308 {
309         struct can_frame *cf;
310         struct sk_buff *skb;
311         int i;
312         struct net_device_stats *stats = &dev->netdev->stats;
313
314         skb = alloc_can_skb(dev->netdev, &cf);
315         if (skb == NULL)
316                 return;
317
318         cf->can_id = msg->msg.can_msg.id;
319         cf->can_dlc = min_t(u8, msg->msg.can_msg.length, 8);
320
321         if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME
322             || msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
323                 cf->can_id |= CAN_EFF_FLAG;
324
325         if (msg->type == CPC_MSG_TYPE_RTR_FRAME
326             || msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
327                 cf->can_id |= CAN_RTR_FLAG;
328         } else {
329                 for (i = 0; i < cf->can_dlc; i++)
330                         cf->data[i] = msg->msg.can_msg.msg[i];
331         }
332
333         netif_rx(skb);
334
335         stats->rx_packets++;
336         stats->rx_bytes += cf->can_dlc;
337 }
338
339 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
340 {
341         struct can_frame *cf;
342         struct sk_buff *skb;
343         struct net_device_stats *stats = &dev->netdev->stats;
344
345         skb = alloc_can_err_skb(dev->netdev, &cf);
346         if (skb == NULL)
347                 return;
348
349         if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
350                 u8 state = msg->msg.can_state;
351
352                 if (state & SJA1000_SR_BS) {
353                         dev->can.state = CAN_STATE_BUS_OFF;
354                         cf->can_id |= CAN_ERR_BUSOFF;
355
356                         can_bus_off(dev->netdev);
357                 } else if (state & SJA1000_SR_ES) {
358                         dev->can.state = CAN_STATE_ERROR_WARNING;
359                         dev->can.can_stats.error_warning++;
360                 } else {
361                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
362                         dev->can.can_stats.error_passive++;
363                 }
364         } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
365                 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
366                 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
367                 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
368
369                 /* bus error interrupt */
370                 dev->can.can_stats.bus_error++;
371                 stats->rx_errors++;
372
373                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
374
375                 switch (ecc & SJA1000_ECC_MASK) {
376                 case SJA1000_ECC_BIT:
377                         cf->data[2] |= CAN_ERR_PROT_BIT;
378                         break;
379                 case SJA1000_ECC_FORM:
380                         cf->data[2] |= CAN_ERR_PROT_FORM;
381                         break;
382                 case SJA1000_ECC_STUFF:
383                         cf->data[2] |= CAN_ERR_PROT_STUFF;
384                         break;
385                 default:
386                         cf->data[2] |= CAN_ERR_PROT_UNSPEC;
387                         cf->data[3] = ecc & SJA1000_ECC_SEG;
388                         break;
389                 }
390
391                 /* Error occured during transmission? */
392                 if ((ecc & SJA1000_ECC_DIR) == 0)
393                         cf->data[2] |= CAN_ERR_PROT_TX;
394
395                 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
396                     dev->can.state == CAN_STATE_ERROR_PASSIVE) {
397                         cf->data[1] = (txerr > rxerr) ?
398                             CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
399                 }
400         } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
401                 cf->can_id |= CAN_ERR_CRTL;
402                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
403
404                 stats->rx_over_errors++;
405                 stats->rx_errors++;
406         }
407
408         netif_rx(skb);
409
410         stats->rx_packets++;
411         stats->rx_bytes += cf->can_dlc;
412 }
413
414 /*
415  * callback for bulk IN urb
416  */
417 static void ems_usb_read_bulk_callback(struct urb *urb)
418 {
419         struct ems_usb *dev = urb->context;
420         struct net_device *netdev;
421         int retval;
422
423         netdev = dev->netdev;
424
425         if (!netif_device_present(netdev))
426                 return;
427
428         switch (urb->status) {
429         case 0: /* success */
430                 break;
431
432         case -ENOENT:
433                 return;
434
435         default:
436                 dev_info(netdev->dev.parent, "Rx URB aborted (%d)\n",
437                          urb->status);
438                 goto resubmit_urb;
439         }
440
441         if (urb->actual_length > CPC_HEADER_SIZE) {
442                 struct ems_cpc_msg *msg;
443                 u8 *ibuf = urb->transfer_buffer;
444                 u8 msg_count, again, start;
445
446                 msg_count = ibuf[0] & ~0x80;
447                 again = ibuf[0] & 0x80;
448
449                 start = CPC_HEADER_SIZE;
450
451                 while (msg_count) {
452                         msg = (struct ems_cpc_msg *)&ibuf[start];
453
454                         switch (msg->type) {
455                         case CPC_MSG_TYPE_CAN_STATE:
456                                 /* Process CAN state changes */
457                                 ems_usb_rx_err(dev, msg);
458                                 break;
459
460                         case CPC_MSG_TYPE_CAN_FRAME:
461                         case CPC_MSG_TYPE_EXT_CAN_FRAME:
462                         case CPC_MSG_TYPE_RTR_FRAME:
463                         case CPC_MSG_TYPE_EXT_RTR_FRAME:
464                                 ems_usb_rx_can_msg(dev, msg);
465                                 break;
466
467                         case CPC_MSG_TYPE_CAN_FRAME_ERROR:
468                                 /* Process errorframe */
469                                 ems_usb_rx_err(dev, msg);
470                                 break;
471
472                         case CPC_MSG_TYPE_OVERRUN:
473                                 /* Message lost while receiving */
474                                 ems_usb_rx_err(dev, msg);
475                                 break;
476                         }
477
478                         start += CPC_MSG_HEADER_LEN + msg->length;
479                         msg_count--;
480
481                         if (start > urb->transfer_buffer_length) {
482                                 dev_err(netdev->dev.parent, "format error\n");
483                                 break;
484                         }
485                 }
486         }
487
488 resubmit_urb:
489         usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
490                           urb->transfer_buffer, RX_BUFFER_SIZE,
491                           ems_usb_read_bulk_callback, dev);
492
493         retval = usb_submit_urb(urb, GFP_ATOMIC);
494
495         if (retval == -ENODEV)
496                 netif_device_detach(netdev);
497         else if (retval)
498                 dev_err(netdev->dev.parent,
499                         "failed resubmitting read bulk urb: %d\n", retval);
500
501         return;
502 }
503
504 /*
505  * callback for bulk IN urb
506  */
507 static void ems_usb_write_bulk_callback(struct urb *urb)
508 {
509         struct ems_tx_urb_context *context = urb->context;
510         struct ems_usb *dev;
511         struct net_device *netdev;
512
513         BUG_ON(!context);
514
515         dev = context->dev;
516         netdev = dev->netdev;
517
518         /* free up our allocated buffer */
519         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
520                         urb->transfer_buffer, urb->transfer_dma);
521
522         atomic_dec(&dev->active_tx_urbs);
523
524         if (!netif_device_present(netdev))
525                 return;
526
527         if (urb->status)
528                 dev_info(netdev->dev.parent, "Tx URB aborted (%d)\n",
529                          urb->status);
530
531         netdev->trans_start = jiffies;
532
533         /* transmission complete interrupt */
534         netdev->stats.tx_packets++;
535         netdev->stats.tx_bytes += context->dlc;
536
537         can_get_echo_skb(netdev, context->echo_index);
538
539         /* Release context */
540         context->echo_index = MAX_TX_URBS;
541
542         if (netif_queue_stopped(netdev))
543                 netif_wake_queue(netdev);
544 }
545
546 /*
547  * Send the given CPC command synchronously
548  */
549 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
550 {
551         int actual_length;
552
553         /* Copy payload */
554         memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
555                msg->length + CPC_MSG_HEADER_LEN);
556
557         /* Clear header */
558         memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
559
560         return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
561                             &dev->tx_msg_buffer[0],
562                             msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
563                             &actual_length, 1000);
564 }
565
566 /*
567  * Change CAN controllers' mode register
568  */
569 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
570 {
571         dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
572
573         return ems_usb_command_msg(dev, &dev->active_params);
574 }
575
576 /*
577  * Send a CPC_Control command to change behaviour when interface receives a CAN
578  * message, bus error or CAN state changed notifications.
579  */
580 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
581 {
582         struct ems_cpc_msg cmd;
583
584         cmd.type = CPC_CMD_TYPE_CONTROL;
585         cmd.length = CPC_MSG_HEADER_LEN + 1;
586
587         cmd.msgid = 0;
588
589         cmd.msg.generic[0] = val;
590
591         return ems_usb_command_msg(dev, &cmd);
592 }
593
594 /*
595  * Start interface
596  */
597 static int ems_usb_start(struct ems_usb *dev)
598 {
599         struct net_device *netdev = dev->netdev;
600         int err, i;
601
602         dev->intr_in_buffer[0] = 0;
603         dev->free_slots = 15; /* initial size */
604
605         for (i = 0; i < MAX_RX_URBS; i++) {
606                 struct urb *urb = NULL;
607                 u8 *buf = NULL;
608
609                 /* create a URB, and a buffer for it */
610                 urb = usb_alloc_urb(0, GFP_KERNEL);
611                 if (!urb) {
612                         dev_err(netdev->dev.parent,
613                                 "No memory left for URBs\n");
614                         return -ENOMEM;
615                 }
616
617                 buf = usb_buffer_alloc(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
618                                        &urb->transfer_dma);
619                 if (!buf) {
620                         dev_err(netdev->dev.parent,
621                                 "No memory left for USB buffer\n");
622                         usb_free_urb(urb);
623                         return -ENOMEM;
624                 }
625
626                 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
627                                   buf, RX_BUFFER_SIZE,
628                                   ems_usb_read_bulk_callback, dev);
629                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
630                 usb_anchor_urb(urb, &dev->rx_submitted);
631
632                 err = usb_submit_urb(urb, GFP_KERNEL);
633                 if (err) {
634                         if (err == -ENODEV)
635                                 netif_device_detach(dev->netdev);
636
637                         usb_unanchor_urb(urb);
638                         usb_buffer_free(dev->udev, RX_BUFFER_SIZE, buf,
639                                         urb->transfer_dma);
640                         break;
641                 }
642
643                 /* Drop reference, USB core will take care of freeing it */
644                 usb_free_urb(urb);
645         }
646
647         /* Did we submit any URBs */
648         if (i == 0) {
649                 dev_warn(netdev->dev.parent, "couldn't setup read URBs\n");
650                 return err;
651         }
652
653         /* Warn if we've couldn't transmit all the URBs */
654         if (i < MAX_RX_URBS)
655                 dev_warn(netdev->dev.parent, "rx performance may be slow\n");
656
657         /* Setup and start interrupt URB */
658         usb_fill_int_urb(dev->intr_urb, dev->udev,
659                          usb_rcvintpipe(dev->udev, 1),
660                          dev->intr_in_buffer,
661                          INTR_IN_BUFFER_SIZE,
662                          ems_usb_read_interrupt_callback, dev, 1);
663
664         err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
665         if (err) {
666                 if (err == -ENODEV)
667                         netif_device_detach(dev->netdev);
668
669                 dev_warn(netdev->dev.parent, "intr URB submit failed: %d\n",
670                          err);
671
672                 return err;
673         }
674
675         /* CPC-USB will transfer received message to host */
676         err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
677         if (err)
678                 goto failed;
679
680         /* CPC-USB will transfer CAN state changes to host */
681         err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
682         if (err)
683                 goto failed;
684
685         /* CPC-USB will transfer bus errors to host */
686         err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
687         if (err)
688                 goto failed;
689
690         err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
691         if (err)
692                 goto failed;
693
694         dev->can.state = CAN_STATE_ERROR_ACTIVE;
695
696         return 0;
697
698 failed:
699         if (err == -ENODEV)
700                 netif_device_detach(dev->netdev);
701
702         dev_warn(netdev->dev.parent, "couldn't submit control: %d\n", err);
703
704         return err;
705 }
706
707 static void unlink_all_urbs(struct ems_usb *dev)
708 {
709         int i;
710
711         usb_unlink_urb(dev->intr_urb);
712
713         usb_kill_anchored_urbs(&dev->rx_submitted);
714
715         usb_kill_anchored_urbs(&dev->tx_submitted);
716         atomic_set(&dev->active_tx_urbs, 0);
717
718         for (i = 0; i < MAX_TX_URBS; i++)
719                 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
720 }
721
722 static int ems_usb_open(struct net_device *netdev)
723 {
724         struct ems_usb *dev = netdev_priv(netdev);
725         int err;
726
727         err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
728         if (err)
729                 return err;
730
731         /* common open */
732         err = open_candev(netdev);
733         if (err)
734                 return err;
735
736         /* finally start device */
737         err = ems_usb_start(dev);
738         if (err) {
739                 if (err == -ENODEV)
740                         netif_device_detach(dev->netdev);
741
742                 dev_warn(netdev->dev.parent, "couldn't start device: %d\n",
743                          err);
744
745                 close_candev(netdev);
746
747                 return err;
748         }
749
750         dev->open_time = jiffies;
751
752         netif_start_queue(netdev);
753
754         return 0;
755 }
756
757 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
758 {
759         struct ems_usb *dev = netdev_priv(netdev);
760         struct ems_tx_urb_context *context = NULL;
761         struct net_device_stats *stats = &netdev->stats;
762         struct can_frame *cf = (struct can_frame *)skb->data;
763         struct ems_cpc_msg *msg;
764         struct urb *urb;
765         u8 *buf;
766         int i, err;
767         size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
768                         + sizeof(struct cpc_can_msg);
769
770         /* create a URB, and a buffer for it, and copy the data to the URB */
771         urb = usb_alloc_urb(0, GFP_ATOMIC);
772         if (!urb) {
773                 dev_err(netdev->dev.parent, "No memory left for URBs\n");
774                 goto nomem;
775         }
776
777         buf = usb_buffer_alloc(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
778         if (!buf) {
779                 dev_err(netdev->dev.parent, "No memory left for USB buffer\n");
780                 usb_free_urb(urb);
781                 goto nomem;
782         }
783
784         msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
785
786         msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK;
787         msg->msg.can_msg.length = cf->can_dlc;
788
789         if (cf->can_id & CAN_RTR_FLAG) {
790                 msg->type = cf->can_id & CAN_EFF_FLAG ?
791                         CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
792
793                 msg->length = CPC_CAN_MSG_MIN_SIZE;
794         } else {
795                 msg->type = cf->can_id & CAN_EFF_FLAG ?
796                         CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
797
798                 for (i = 0; i < cf->can_dlc; i++)
799                         msg->msg.can_msg.msg[i] = cf->data[i];
800
801                 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
802         }
803
804         for (i = 0; i < MAX_TX_URBS; i++) {
805                 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
806                         context = &dev->tx_contexts[i];
807                         break;
808                 }
809         }
810
811         /*
812          * May never happen! When this happens we'd more URBs in flight as
813          * allowed (MAX_TX_URBS).
814          */
815         if (!context) {
816                 usb_unanchor_urb(urb);
817                 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma);
818
819                 dev_warn(netdev->dev.parent, "couldn't find free context\n");
820
821                 return NETDEV_TX_BUSY;
822         }
823
824         context->dev = dev;
825         context->echo_index = i;
826         context->dlc = cf->can_dlc;
827
828         usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
829                           size, ems_usb_write_bulk_callback, context);
830         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
831         usb_anchor_urb(urb, &dev->tx_submitted);
832
833         can_put_echo_skb(skb, netdev, context->echo_index);
834
835         atomic_inc(&dev->active_tx_urbs);
836
837         err = usb_submit_urb(urb, GFP_ATOMIC);
838         if (unlikely(err)) {
839                 can_free_echo_skb(netdev, context->echo_index);
840
841                 usb_unanchor_urb(urb);
842                 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma);
843                 dev_kfree_skb(skb);
844
845                 atomic_dec(&dev->active_tx_urbs);
846
847                 if (err == -ENODEV) {
848                         netif_device_detach(netdev);
849                 } else {
850                         dev_warn(netdev->dev.parent, "failed tx_urb %d\n", err);
851
852                         stats->tx_dropped++;
853                 }
854         } else {
855                 netdev->trans_start = jiffies;
856
857                 /* Slow down tx path */
858                 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
859                     dev->free_slots < 5) {
860                         netif_stop_queue(netdev);
861                 }
862         }
863
864         /*
865          * Release our reference to this URB, the USB core will eventually free
866          * it entirely.
867          */
868         usb_free_urb(urb);
869
870         return NETDEV_TX_OK;
871
872 nomem:
873         if (skb)
874                 dev_kfree_skb(skb);
875
876         stats->tx_dropped++;
877
878         return NETDEV_TX_OK;
879 }
880
881 static int ems_usb_close(struct net_device *netdev)
882 {
883         struct ems_usb *dev = netdev_priv(netdev);
884
885         /* Stop polling */
886         unlink_all_urbs(dev);
887
888         netif_stop_queue(netdev);
889
890         /* Set CAN controller to reset mode */
891         if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
892                 dev_warn(netdev->dev.parent, "couldn't stop device");
893
894         close_candev(netdev);
895
896         dev->open_time = 0;
897
898         return 0;
899 }
900
901 static const struct net_device_ops ems_usb_netdev_ops = {
902         .ndo_open = ems_usb_open,
903         .ndo_stop = ems_usb_close,
904         .ndo_start_xmit = ems_usb_start_xmit,
905 };
906
907 static struct can_bittiming_const ems_usb_bittiming_const = {
908         .name = "ems_usb",
909         .tseg1_min = 1,
910         .tseg1_max = 16,
911         .tseg2_min = 1,
912         .tseg2_max = 8,
913         .sjw_max = 4,
914         .brp_min = 1,
915         .brp_max = 64,
916         .brp_inc = 1,
917 };
918
919 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
920 {
921         struct ems_usb *dev = netdev_priv(netdev);
922
923         if (!dev->open_time)
924                 return -EINVAL;
925
926         switch (mode) {
927         case CAN_MODE_START:
928                 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
929                         dev_warn(netdev->dev.parent, "couldn't start device");
930
931                 if (netif_queue_stopped(netdev))
932                         netif_wake_queue(netdev);
933                 break;
934
935         default:
936                 return -EOPNOTSUPP;
937         }
938
939         return 0;
940 }
941
942 static int ems_usb_set_bittiming(struct net_device *netdev)
943 {
944         struct ems_usb *dev = netdev_priv(netdev);
945         struct can_bittiming *bt = &dev->can.bittiming;
946         u8 btr0, btr1;
947
948         btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
949         btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
950                 (((bt->phase_seg2 - 1) & 0x7) << 4);
951         if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
952                 btr1 |= 0x80;
953
954         dev_info(netdev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
955                  btr0, btr1);
956
957         dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
958         dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
959
960         return ems_usb_command_msg(dev, &dev->active_params);
961 }
962
963 static void init_params_sja1000(struct ems_cpc_msg *msg)
964 {
965         struct cpc_sja1000_params *sja1000 =
966                 &msg->msg.can_params.cc_params.sja1000;
967
968         msg->type = CPC_CMD_TYPE_CAN_PARAMS;
969         msg->length = sizeof(struct cpc_can_params);
970         msg->msgid = 0;
971
972         msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
973
974         /* Acceptance filter open */
975         sja1000->acc_code0 = 0x00;
976         sja1000->acc_code1 = 0x00;
977         sja1000->acc_code2 = 0x00;
978         sja1000->acc_code3 = 0x00;
979
980         /* Acceptance filter open */
981         sja1000->acc_mask0 = 0xFF;
982         sja1000->acc_mask1 = 0xFF;
983         sja1000->acc_mask2 = 0xFF;
984         sja1000->acc_mask3 = 0xFF;
985
986         sja1000->btr0 = 0;
987         sja1000->btr1 = 0;
988
989         sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
990         sja1000->mode = SJA1000_MOD_RM;
991 }
992
993 /*
994  * probe function for new CPC-USB devices
995  */
996 static int ems_usb_probe(struct usb_interface *intf,
997                          const struct usb_device_id *id)
998 {
999         struct net_device *netdev;
1000         struct ems_usb *dev;
1001         int i, err = -ENOMEM;
1002
1003         netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
1004         if (!netdev) {
1005                 dev_err(netdev->dev.parent, "Couldn't alloc candev\n");
1006                 return -ENOMEM;
1007         }
1008
1009         dev = netdev_priv(netdev);
1010
1011         dev->udev = interface_to_usbdev(intf);
1012         dev->netdev = netdev;
1013
1014         dev->can.state = CAN_STATE_STOPPED;
1015         dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1016         dev->can.bittiming_const = &ems_usb_bittiming_const;
1017         dev->can.do_set_bittiming = ems_usb_set_bittiming;
1018         dev->can.do_set_mode = ems_usb_set_mode;
1019
1020         netdev->flags |= IFF_ECHO; /* we support local echo */
1021
1022         netdev->netdev_ops = &ems_usb_netdev_ops;
1023
1024         netdev->flags |= IFF_ECHO; /* we support local echo */
1025
1026         init_usb_anchor(&dev->rx_submitted);
1027
1028         init_usb_anchor(&dev->tx_submitted);
1029         atomic_set(&dev->active_tx_urbs, 0);
1030
1031         for (i = 0; i < MAX_TX_URBS; i++)
1032                 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1033
1034         dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1035         if (!dev->intr_urb) {
1036                 dev_err(netdev->dev.parent, "Couldn't alloc intr URB\n");
1037                 goto cleanup_candev;
1038         }
1039
1040         dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1041         if (!dev->intr_in_buffer) {
1042                 dev_err(netdev->dev.parent, "Couldn't alloc Intr buffer\n");
1043                 goto cleanup_intr_urb;
1044         }
1045
1046         dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1047                                      sizeof(struct ems_cpc_msg), GFP_KERNEL);
1048         if (!dev->tx_msg_buffer) {
1049                 dev_err(netdev->dev.parent, "Couldn't alloc Tx buffer\n");
1050                 goto cleanup_intr_in_buffer;
1051         }
1052
1053         usb_set_intfdata(intf, dev);
1054
1055         SET_NETDEV_DEV(netdev, &intf->dev);
1056
1057         init_params_sja1000(&dev->active_params);
1058
1059         err = ems_usb_command_msg(dev, &dev->active_params);
1060         if (err) {
1061                 dev_err(netdev->dev.parent,
1062                         "couldn't initialize controller: %d\n", err);
1063                 goto cleanup_tx_msg_buffer;
1064         }
1065
1066         err = register_candev(netdev);
1067         if (err) {
1068                 dev_err(netdev->dev.parent,
1069                         "couldn't register CAN device: %d\n", err);
1070                 goto cleanup_tx_msg_buffer;
1071         }
1072
1073         return 0;
1074
1075 cleanup_tx_msg_buffer:
1076         kfree(dev->tx_msg_buffer);
1077
1078 cleanup_intr_in_buffer:
1079         kfree(dev->intr_in_buffer);
1080
1081 cleanup_intr_urb:
1082         usb_free_urb(dev->intr_urb);
1083
1084 cleanup_candev:
1085         free_candev(netdev);
1086
1087         return err;
1088 }
1089
1090 /*
1091  * called by the usb core when the device is removed from the system
1092  */
1093 static void ems_usb_disconnect(struct usb_interface *intf)
1094 {
1095         struct ems_usb *dev = usb_get_intfdata(intf);
1096
1097         usb_set_intfdata(intf, NULL);
1098
1099         if (dev) {
1100                 unregister_netdev(dev->netdev);
1101                 free_candev(dev->netdev);
1102
1103                 unlink_all_urbs(dev);
1104
1105                 usb_free_urb(dev->intr_urb);
1106
1107                 kfree(dev->intr_in_buffer);
1108         }
1109 }
1110
1111 /* usb specific object needed to register this driver with the usb subsystem */
1112 static struct usb_driver ems_usb_driver = {
1113         .name = "ems_usb",
1114         .probe = ems_usb_probe,
1115         .disconnect = ems_usb_disconnect,
1116         .id_table = ems_usb_table,
1117 };
1118
1119 static int __init ems_usb_init(void)
1120 {
1121         int err;
1122
1123         printk(KERN_INFO "CPC-USB kernel driver loaded\n");
1124
1125         /* register this driver with the USB subsystem */
1126         err = usb_register(&ems_usb_driver);
1127
1128         if (err) {
1129                 err("usb_register failed. Error number %d\n", err);
1130                 return err;
1131         }
1132
1133         return 0;
1134 }
1135
1136 static void __exit ems_usb_exit(void)
1137 {
1138         /* deregister this driver with the USB subsystem */
1139         usb_deregister(&ems_usb_driver);
1140 }
1141
1142 module_init(ems_usb_init);
1143 module_exit(ems_usb_exit);