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can: do not copy the payload of RTR frames
[linux-2.6-block.git] / drivers / net / can / usb / ems_usb.c
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935912c5 1// SPDX-License-Identifier: GPL-2.0-only
702171ad
SH		 2/*
3 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
4 *
5 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
702171ad 6 */
702171ad
SH		 7#include <linux/signal.h>
8#include <linux/slab.h>
9#include <linux/module.h>
10#include <linux/netdevice.h>
11#include <linux/usb.h>
12
13#include <linux/can.h>
14#include <linux/can/dev.h>
15#include <linux/can/error.h>
16
17MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
18MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
19MODULE_LICENSE("GPL v2");
20
21/* Control-Values for CPC_Control() Command Subject Selection */
22#define CONTR_CAN_MESSAGE 0x04
23#define CONTR_CAN_STATE 0x0C
24#define CONTR_BUS_ERROR 0x1C
25
26/* Control Command Actions */
27#define CONTR_CONT_OFF 0
28#define CONTR_CONT_ON 1
29#define CONTR_ONCE 2
30
31/* Messages from CPC to PC */
32#define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
33#define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
34#define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
35#define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
36#define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
37#define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
38#define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
39#define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
40#define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
41#define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
42#define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
43
44/* Messages from the PC to the CPC interface */
45#define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
46#define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
47#define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
48#define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
49#define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
50#define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
51#define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
52#define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
53
54#define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
55#define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
56#define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
57
58#define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
59
60#define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
61
62/* Overrun types */
63#define CPC_OVR_EVENT_CAN 0x01
64#define CPC_OVR_EVENT_CANSTATE 0x02
65#define CPC_OVR_EVENT_BUSERROR 0x04
66
67/*
68 * If the CAN controller lost a message we indicate it with the highest bit
69 * set in the count field.
70 */
71#define CPC_OVR_HW 0x80
72
73/* Size of the "struct ems_cpc_msg" without the union */
74#define CPC_MSG_HEADER_LEN 11
75#define CPC_CAN_MSG_MIN_SIZE 5
76
77/* Define these values to match your devices */
78#define USB_CPCUSB_VENDOR_ID 0x12D6
79
80#define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
81
82/* Mode register NXP LPC2119/SJA1000 CAN Controller */
83#define SJA1000_MOD_NORMAL 0x00
84#define SJA1000_MOD_RM 0x01
85
86/* ECC register NXP LPC2119/SJA1000 CAN Controller */
87#define SJA1000_ECC_SEG 0x1F
88#define SJA1000_ECC_DIR 0x20
89#define SJA1000_ECC_ERR 0x06
90#define SJA1000_ECC_BIT 0x00
91#define SJA1000_ECC_FORM 0x40
92#define SJA1000_ECC_STUFF 0x80
93#define SJA1000_ECC_MASK 0xc0
94
95/* Status register content */
96#define SJA1000_SR_BS 0x80
97#define SJA1000_SR_ES 0x40
98
99#define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
100
101/*
102 * The device actually uses a 16MHz clock to generate the CAN clock
103 * but it expects SJA1000 bit settings based on 8MHz (is internally
104 * converted).
105 */
106#define EMS_USB_ARM7_CLOCK 8000000
107
90cfde46
GU		 108#define CPC_TX_QUEUE_TRIGGER_LOW 25
109#define CPC_TX_QUEUE_TRIGGER_HIGH 35
110
702171ad
SH		 111/*
112 * CAN-Message representation in a CPC_MSG. Message object type is
113 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
114 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
115 */
116struct cpc_can_msg {
8a4b5b0f 117 __le32 id;
702171ad
SH		 118 u8 length;
119 u8 msg[8];
120};
121
122/* Representation of the CAN parameters for the SJA1000 controller */
123struct cpc_sja1000_params {
124 u8 mode;
125 u8 acc_code0;
126 u8 acc_code1;
127 u8 acc_code2;
128 u8 acc_code3;
129 u8 acc_mask0;
130 u8 acc_mask1;
131 u8 acc_mask2;
132 u8 acc_mask3;
133 u8 btr0;
134 u8 btr1;
135 u8 outp_contr;
136};
137
138/* CAN params message representation */
139struct cpc_can_params {
140 u8 cc_type;
141
142 /* Will support M16C CAN controller in the future */
143 union {
144 struct cpc_sja1000_params sja1000;
145 } cc_params;
146};
147
148/* Structure for confirmed message handling */
149struct cpc_confirm {
150 u8 error; /* error code */
151};
152
153/* Structure for overrun conditions */
154struct cpc_overrun {
155 u8 event;
156 u8 count;
157};
158
159/* SJA1000 CAN errors (compatible to NXP LPC2119) */
160struct cpc_sja1000_can_error {
161 u8 ecc;
162 u8 rxerr;
163 u8 txerr;
164};
165
166/* structure for CAN error conditions */
167struct cpc_can_error {
168 u8 ecode;
169
170 struct {
171 u8 cc_type;
172
173 /* Other controllers may also provide error code capture regs */
174 union {
175 struct cpc_sja1000_can_error sja1000;
176 } regs;
177 } cc;
178};
179
180/*
181 * Structure containing RX/TX error counter. This structure is used to request
182 * the values of the CAN controllers TX and RX error counter.
183 */
184struct cpc_can_err_counter {
185 u8 rx;
186 u8 tx;
187};
188
189/* Main message type used between library and application */
ba2d3587 190struct __packed ems_cpc_msg {
702171ad
SH		 191 u8 type; /* type of message */
192 u8 length; /* length of data within union 'msg' */
193 u8 msgid; /* confirmation handle */
a0bc163a
MKB		 194 __le32 ts_sec; /* timestamp in seconds */
195 __le32 ts_nsec; /* timestamp in nano seconds */
702171ad
SH		 196
197 union {
198 u8 generic[64];
199 struct cpc_can_msg can_msg;
200 struct cpc_can_params can_params;
201 struct cpc_confirm confirmation;
202 struct cpc_overrun overrun;
203 struct cpc_can_error error;
204 struct cpc_can_err_counter err_counter;
205 u8 can_state;
206 } msg;
207};
208
209/*
210 * Table of devices that work with this driver
211 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
212 */
213static struct usb_device_id ems_usb_table[] = {
214 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
215 {} /* Terminating entry */
216};
217
218MODULE_DEVICE_TABLE(usb, ems_usb_table);
219
220#define RX_BUFFER_SIZE 64
221#define CPC_HEADER_SIZE 4
222#define INTR_IN_BUFFER_SIZE 4
223
224#define MAX_RX_URBS 10
a6e4bc53 225#define MAX_TX_URBS 10
702171ad
SH		 226
227struct ems_usb;
228
229struct ems_tx_urb_context {
230 struct ems_usb *dev;
231
232 u32 echo_index;
233 u8 dlc;
234};
235
236struct ems_usb {
237 struct can_priv can; /* must be the first member */
702171ad
SH		 238
239 struct sk_buff *echo_skb[MAX_TX_URBS];
240
241 struct usb_device *udev;
242 struct net_device *netdev;
243
244 atomic_t active_tx_urbs;
245 struct usb_anchor tx_submitted;
246 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
247
248 struct usb_anchor rx_submitted;
249
250 struct urb *intr_urb;
251
252 u8 *tx_msg_buffer;
253
254 u8 *intr_in_buffer;
255 unsigned int free_slots; /* remember number of available slots */
256
257 struct ems_cpc_msg active_params; /* active controller parameters */
9969e3c5
PS		 258 void *rxbuf[MAX_RX_URBS];
259 dma_addr_t rxbuf_dma[MAX_RX_URBS];
702171ad
SH		 260};
261
262static void ems_usb_read_interrupt_callback(struct urb *urb)
263{
264 struct ems_usb *dev = urb->context;
265 struct net_device *netdev = dev->netdev;
266 int err;
267
268 if (!netif_device_present(netdev))
269 return;
270
271 switch (urb->status) {
272 case 0:
273 dev->free_slots = dev->intr_in_buffer[1];
59097ac9
MKB		 274 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH &&
275 netif_queue_stopped(netdev))
276 netif_wake_queue(netdev);
702171ad
SH		 277 break;
278
279 case -ECONNRESET: /* unlink */
280 case -ENOENT:
bd352e1a
MK		 281 case -EPIPE:
282 case -EPROTO:
702171ad
SH		 283 case -ESHUTDOWN:
284 return;
285
286 default:
aabdfd6a 287 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
702171ad
SH		 288 break;
289 }
290
291 err = usb_submit_urb(urb, GFP_ATOMIC);
292
293 if (err == -ENODEV)
294 netif_device_detach(netdev);
295 else if (err)
aabdfd6a 296 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
702171ad
SH		 297}
298
299static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
300{
301 struct can_frame *cf;
302 struct sk_buff *skb;
303 int i;
304 struct net_device_stats *stats = &dev->netdev->stats;
305
7b6856a0 306 skb = alloc_can_skb(dev->netdev, &cf);
702171ad
SH		 307 if (skb == NULL)
308 return;
309
2b2072e9 310 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
c7b74967 311 cf->len = can_cc_dlc2len(msg->msg.can_msg.length & 0xF);
702171ad 312
8e95a202
JP		 313 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
314 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
702171ad
SH		 315 cf->can_id |= CAN_EFF_FLAG;
316
8e95a202
JP		 317 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
318 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
702171ad
SH		 319 cf->can_id |= CAN_RTR_FLAG;
320 } else {
c7b74967 321 for (i = 0; i < cf->len; i++)
702171ad
SH		 322 cf->data[i] = msg->msg.can_msg.msg[i];
323 }
324
702171ad 325 stats->rx_packets++;
c7b74967 326 stats->rx_bytes += cf->len;
43c021e8 327 netif_rx(skb);
702171ad
SH		 328}
329
330static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
331{
332 struct can_frame *cf;
333 struct sk_buff *skb;
334 struct net_device_stats *stats = &dev->netdev->stats;
335
7b6856a0 336 skb = alloc_can_err_skb(dev->netdev, &cf);
702171ad
SH		 337 if (skb == NULL)
338 return;
339
702171ad
SH		 340 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
341 u8 state = msg->msg.can_state;
342
343 if (state & SJA1000_SR_BS) {
344 dev->can.state = CAN_STATE_BUS_OFF;
345 cf->can_id |= CAN_ERR_BUSOFF;
346
be38a6f9 347 dev->can.can_stats.bus_off++;
702171ad
SH		 348 can_bus_off(dev->netdev);
349 } else if (state & SJA1000_SR_ES) {
350 dev->can.state = CAN_STATE_ERROR_WARNING;
351 dev->can.can_stats.error_warning++;
352 } else {
353 dev->can.state = CAN_STATE_ERROR_ACTIVE;
354 dev->can.can_stats.error_passive++;
355 }
356 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
357 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
358 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
359 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
360
361 /* bus error interrupt */
362 dev->can.can_stats.bus_error++;
363 stats->rx_errors++;
364
365 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
366
367 switch (ecc & SJA1000_ECC_MASK) {
368 case SJA1000_ECC_BIT:
369 cf->data[2] |= CAN_ERR_PROT_BIT;
370 break;
371 case SJA1000_ECC_FORM:
372 cf->data[2] |= CAN_ERR_PROT_FORM;
373 break;
374 case SJA1000_ECC_STUFF:
375 cf->data[2] |= CAN_ERR_PROT_STUFF;
376 break;
377 default:
702171ad
SH		 378 cf->data[3] = ecc & SJA1000_ECC_SEG;
379 break;
380 }
381
25985edc 382 /* Error occurred during transmission? */
702171ad
SH		 383 if ((ecc & SJA1000_ECC_DIR) == 0)
384 cf->data[2] |= CAN_ERR_PROT_TX;
385
386 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
387 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
6ebc5e8f 388 cf->can_id |= CAN_ERR_CRTL;
702171ad
SH		 389 cf->data[1] = (txerr > rxerr) ?
390 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
391 }
392 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
393 cf->can_id |= CAN_ERR_CRTL;
394 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
395
396 stats->rx_over_errors++;
397 stats->rx_errors++;
398 }
399
43c021e8 400 netif_rx(skb);
702171ad
SH		 401}
402
403/*
404 * callback for bulk IN urb
405 */
406static void ems_usb_read_bulk_callback(struct urb *urb)
407{
408 struct ems_usb *dev = urb->context;
409 struct net_device *netdev;
410 int retval;
411
412 netdev = dev->netdev;
413
414 if (!netif_device_present(netdev))
415 return;
416
417 switch (urb->status) {
418 case 0: /* success */
419 break;
420
421 case -ENOENT:
422 return;
423
424 default:
aabdfd6a 425 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
702171ad
SH		 426 goto resubmit_urb;
427 }
428
429 if (urb->actual_length > CPC_HEADER_SIZE) {
430 struct ems_cpc_msg *msg;
431 u8 *ibuf = urb->transfer_buffer;
4e2061b1 432 u8 msg_count, start;
702171ad
SH		 433
434 msg_count = ibuf[0] & ~0x80;
702171ad
SH		 435
436 start = CPC_HEADER_SIZE;
437
438 while (msg_count) {
439 msg = (struct ems_cpc_msg *)&ibuf[start];
440
441 switch (msg->type) {
442 case CPC_MSG_TYPE_CAN_STATE:
443 /* Process CAN state changes */
444 ems_usb_rx_err(dev, msg);
445 break;
446
447 case CPC_MSG_TYPE_CAN_FRAME:
448 case CPC_MSG_TYPE_EXT_CAN_FRAME:
449 case CPC_MSG_TYPE_RTR_FRAME:
450 case CPC_MSG_TYPE_EXT_RTR_FRAME:
451 ems_usb_rx_can_msg(dev, msg);
452 break;
453
454 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
455 /* Process errorframe */
456 ems_usb_rx_err(dev, msg);
457 break;
458
459 case CPC_MSG_TYPE_OVERRUN:
460 /* Message lost while receiving */
461 ems_usb_rx_err(dev, msg);
462 break;
463 }
464
465 start += CPC_MSG_HEADER_LEN + msg->length;
466 msg_count--;
467
468 if (start > urb->transfer_buffer_length) {
aabdfd6a 469 netdev_err(netdev, "format error\n");
702171ad
SH		 470 break;
471 }
472 }
473 }
474
475resubmit_urb:
476 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
477 urb->transfer_buffer, RX_BUFFER_SIZE,
478 ems_usb_read_bulk_callback, dev);
479
480 retval = usb_submit_urb(urb, GFP_ATOMIC);
481
482 if (retval == -ENODEV)
483 netif_device_detach(netdev);
484 else if (retval)
aabdfd6a
WG		 485 netdev_err(netdev,
486 "failed resubmitting read bulk urb: %d\n", retval);
702171ad
SH		 487}
488
489/*
490 * callback for bulk IN urb
491 */
492static void ems_usb_write_bulk_callback(struct urb *urb)
493{
494 struct ems_tx_urb_context *context = urb->context;
495 struct ems_usb *dev;
496 struct net_device *netdev;
497
498 BUG_ON(!context);
499
500 dev = context->dev;
501 netdev = dev->netdev;
502
503 /* free up our allocated buffer */
997ea58e
DM		 504 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
505 urb->transfer_buffer, urb->transfer_dma);
702171ad
SH		 506
507 atomic_dec(&dev->active_tx_urbs);
508
509 if (!netif_device_present(netdev))
510 return;
511
512 if (urb->status)
aabdfd6a 513 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
702171ad 514
860e9538 515 netif_trans_update(netdev);
702171ad
SH		 516
517 /* transmission complete interrupt */
518 netdev->stats.tx_packets++;
519 netdev->stats.tx_bytes += context->dlc;
520
9420e1d4 521 can_get_echo_skb(netdev, context->echo_index, NULL);
702171ad
SH		 522
523 /* Release context */
524 context->echo_index = MAX_TX_URBS;
525
702171ad
SH		 526}
527
528/*
529 * Send the given CPC command synchronously
530 */
531static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
532{
533 int actual_length;
534
535 /* Copy payload */
536 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
537 msg->length + CPC_MSG_HEADER_LEN);
538
539 /* Clear header */
540 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
541
542 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
543 &dev->tx_msg_buffer[0],
544 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
545 &actual_length, 1000);
546}
547
548/*
549 * Change CAN controllers' mode register
550 */
551static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
552{
553 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
554
555 return ems_usb_command_msg(dev, &dev->active_params);
556}
557
558/*
559 * Send a CPC_Control command to change behaviour when interface receives a CAN
560 * message, bus error or CAN state changed notifications.
561 */
562static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
563{
564 struct ems_cpc_msg cmd;
565
566 cmd.type = CPC_CMD_TYPE_CONTROL;
567 cmd.length = CPC_MSG_HEADER_LEN + 1;
568
569 cmd.msgid = 0;
570
571 cmd.msg.generic[0] = val;
572
573 return ems_usb_command_msg(dev, &cmd);
574}
575
576/*
577 * Start interface
578 */
579static int ems_usb_start(struct ems_usb *dev)
580{
581 struct net_device *netdev = dev->netdev;
582 int err, i;
583
584 dev->intr_in_buffer[0] = 0;
90cfde46 585 dev->free_slots = 50; /* initial size */
702171ad
SH		 586
587 for (i = 0; i < MAX_RX_URBS; i++) {
588 struct urb *urb = NULL;
589 u8 *buf = NULL;
9969e3c5 590 dma_addr_t buf_dma;
702171ad
SH		 591
592 /* create a URB, and a buffer for it */
593 urb = usb_alloc_urb(0, GFP_KERNEL);
594 if (!urb) {
2ee6850c
SH		 595 err = -ENOMEM;
596 break;
702171ad
SH		 597 }
598
997ea58e 599 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
9969e3c5 600 &buf_dma);
702171ad 601 if (!buf) {
aabdfd6a 602 netdev_err(netdev, "No memory left for USB buffer\n");
702171ad 603 usb_free_urb(urb);
2ee6850c
SH		 604 err = -ENOMEM;
605 break;
702171ad
SH		 606 }
607
9969e3c5
PS		 608 urb->transfer_dma = buf_dma;
609
702171ad
SH		 610 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
611 buf, RX_BUFFER_SIZE,
612 ems_usb_read_bulk_callback, dev);
613 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
614 usb_anchor_urb(urb, &dev->rx_submitted);
615
616 err = usb_submit_urb(urb, GFP_KERNEL);
617 if (err) {
702171ad 618 usb_unanchor_urb(urb);
997ea58e
DM		 619 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
620 urb->transfer_dma);
a1c31f1d 621 usb_free_urb(urb);
702171ad
SH		 622 break;
623 }
624
9969e3c5
PS		 625 dev->rxbuf[i] = buf;
626 dev->rxbuf_dma[i] = buf_dma;
627
702171ad
SH		 628 /* Drop reference, USB core will take care of freeing it */
629 usb_free_urb(urb);
630 }
631
632 /* Did we submit any URBs */
633 if (i == 0) {
aabdfd6a 634 netdev_warn(netdev, "couldn't setup read URBs\n");
702171ad
SH		 635 return err;
636 }
637
638 /* Warn if we've couldn't transmit all the URBs */
639 if (i < MAX_RX_URBS)
aabdfd6a 640 netdev_warn(netdev, "rx performance may be slow\n");
702171ad
SH		 641
642 /* Setup and start interrupt URB */
643 usb_fill_int_urb(dev->intr_urb, dev->udev,
644 usb_rcvintpipe(dev->udev, 1),
645 dev->intr_in_buffer,
646 INTR_IN_BUFFER_SIZE,
647 ems_usb_read_interrupt_callback, dev, 1);
648
649 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
650 if (err) {
aabdfd6a 651 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
702171ad
SH		 652
653 return err;
654 }
655
656 /* CPC-USB will transfer received message to host */
657 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
658 if (err)
659 goto failed;
660
661 /* CPC-USB will transfer CAN state changes to host */
662 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
663 if (err)
664 goto failed;
665
666 /* CPC-USB will transfer bus errors to host */
667 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
668 if (err)
669 goto failed;
670
671 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
672 if (err)
673 goto failed;
674
675 dev->can.state = CAN_STATE_ERROR_ACTIVE;
676
677 return 0;
678
679failed:
aabdfd6a 680 netdev_warn(netdev, "couldn't submit control: %d\n", err);
702171ad
SH		 681
682 return err;
683}
684
685static void unlink_all_urbs(struct ems_usb *dev)
686{
687 int i;
688
689 usb_unlink_urb(dev->intr_urb);
690
691 usb_kill_anchored_urbs(&dev->rx_submitted);
692
9969e3c5
PS		 693 for (i = 0; i < MAX_RX_URBS; ++i)
694 usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
695 dev->rxbuf[i], dev->rxbuf_dma[i]);
696
702171ad
SH		 697 usb_kill_anchored_urbs(&dev->tx_submitted);
698 atomic_set(&dev->active_tx_urbs, 0);
699
700 for (i = 0; i < MAX_TX_URBS; i++)
701 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
702}
703
704static int ems_usb_open(struct net_device *netdev)
705{
706 struct ems_usb *dev = netdev_priv(netdev);
707 int err;
708
709 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
710 if (err)
711 return err;
712
713 /* common open */
714 err = open_candev(netdev);
715 if (err)
716 return err;
717
718 /* finally start device */
719 err = ems_usb_start(dev);
720 if (err) {
721 if (err == -ENODEV)
722 netif_device_detach(dev->netdev);
723
aabdfd6a 724 netdev_warn(netdev, "couldn't start device: %d\n", err);
702171ad
SH		 725
726 close_candev(netdev);
727
728 return err;
729 }
730
702171ad
SH		 731
732 netif_start_queue(netdev);
733
734 return 0;
735}
736
737static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
738{
739 struct ems_usb *dev = netdev_priv(netdev);
740 struct ems_tx_urb_context *context = NULL;
741 struct net_device_stats *stats = &netdev->stats;
742 struct can_frame *cf = (struct can_frame *)skb->data;
743 struct ems_cpc_msg *msg;
744 struct urb *urb;
745 u8 *buf;
746 int i, err;
747 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
748 + sizeof(struct cpc_can_msg);
749
3ccd4c61
OH		 750 if (can_dropped_invalid_skb(netdev, skb))
751 return NETDEV_TX_OK;
752
702171ad
SH		 753 /* create a URB, and a buffer for it, and copy the data to the URB */
754 urb = usb_alloc_urb(0, GFP_ATOMIC);
87ced2f9 755 if (!urb)
702171ad 756 goto nomem;
702171ad 757
997ea58e 758 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
702171ad 759 if (!buf) {
aabdfd6a 760 netdev_err(netdev, "No memory left for USB buffer\n");
702171ad
SH		 761 usb_free_urb(urb);
762 goto nomem;
763 }
764
765 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
766
8a4b5b0f 767 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
c7b74967 768 msg->msg.can_msg.length = cf->len;
702171ad
SH		 769
770 if (cf->can_id & CAN_RTR_FLAG) {
771 msg->type = cf->can_id & CAN_EFF_FLAG ?
772 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
773
774 msg->length = CPC_CAN_MSG_MIN_SIZE;
775 } else {
776 msg->type = cf->can_id & CAN_EFF_FLAG ?
777 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
778
c7b74967 779 for (i = 0; i < cf->len; i++)
702171ad
SH		 780 msg->msg.can_msg.msg[i] = cf->data[i];
781
c7b74967 782 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len;
702171ad
SH		 783 }
784
785 for (i = 0; i < MAX_TX_URBS; i++) {
786 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
787 context = &dev->tx_contexts[i];
788 break;
789 }
790 }
791
792 /*
793 * May never happen! When this happens we'd more URBs in flight as
794 * allowed (MAX_TX_URBS).
795 */
796 if (!context) {
997ea58e 797 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
a1c31f1d 798 usb_free_urb(urb);
702171ad 799
aabdfd6a 800 netdev_warn(netdev, "couldn't find free context\n");
702171ad
SH		 801
802 return NETDEV_TX_BUSY;
803 }
804
805 context->dev = dev;
806 context->echo_index = i;
c7b74967 807 context->dlc = cf->len;
702171ad
SH		 808
809 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
810 size, ems_usb_write_bulk_callback, context);
811 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
812 usb_anchor_urb(urb, &dev->tx_submitted);
813
1dcb6e57 814 can_put_echo_skb(skb, netdev, context->echo_index, 0);
702171ad
SH		 815
816 atomic_inc(&dev->active_tx_urbs);
817
818 err = usb_submit_urb(urb, GFP_ATOMIC);
819 if (unlikely(err)) {
f318482a 820 can_free_echo_skb(netdev, context->echo_index, NULL);
702171ad
SH		 821
822 usb_unanchor_urb(urb);
997ea58e 823 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
702171ad
SH		 824 dev_kfree_skb(skb);
825
826 atomic_dec(&dev->active_tx_urbs);
827
828 if (err == -ENODEV) {
829 netif_device_detach(netdev);
830 } else {
aabdfd6a 831 netdev_warn(netdev, "failed tx_urb %d\n", err);
702171ad
SH		 832
833 stats->tx_dropped++;
834 }
835 } else {
860e9538 836 netif_trans_update(netdev);
702171ad
SH		 837
838 /* Slow down tx path */
839 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
90cfde46 840 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
702171ad
SH		 841 netif_stop_queue(netdev);
842 }
843 }
844
845 /*
846 * Release our reference to this URB, the USB core will eventually free
847 * it entirely.
848 */
849 usb_free_urb(urb);
850
851 return NETDEV_TX_OK;
852
853nomem:
ea3fb371 854 dev_kfree_skb(skb);
702171ad
SH		 855 stats->tx_dropped++;
856
857 return NETDEV_TX_OK;
858}
859
860static int ems_usb_close(struct net_device *netdev)
861{
862 struct ems_usb *dev = netdev_priv(netdev);
863
864 /* Stop polling */
865 unlink_all_urbs(dev);
866
867 netif_stop_queue(netdev);
868
869 /* Set CAN controller to reset mode */
870 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
aabdfd6a 871 netdev_warn(netdev, "couldn't stop device");
702171ad
SH		 872
873 close_candev(netdev);
874
702171ad
SH		 875 return 0;
876}
877
878static const struct net_device_ops ems_usb_netdev_ops = {
879 .ndo_open = ems_usb_open,
880 .ndo_stop = ems_usb_close,
881 .ndo_start_xmit = ems_usb_start_xmit,
c971fa2a 882 .ndo_change_mtu = can_change_mtu,
702171ad
SH		 883};
884
194b9a4c 885static const struct can_bittiming_const ems_usb_bittiming_const = {
702171ad
SH		 886 .name = "ems_usb",
887 .tseg1_min = 1,
888 .tseg1_max = 16,
889 .tseg2_min = 1,
890 .tseg2_max = 8,
891 .sjw_max = 4,
892 .brp_min = 1,
893 .brp_max = 64,
894 .brp_inc = 1,
895};
896
897static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
898{
899 struct ems_usb *dev = netdev_priv(netdev);
900
702171ad
SH		 901 switch (mode) {
902 case CAN_MODE_START:
903 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
aabdfd6a 904 netdev_warn(netdev, "couldn't start device");
702171ad
SH		 905
906 if (netif_queue_stopped(netdev))
907 netif_wake_queue(netdev);
908 break;
909
910 default:
911 return -EOPNOTSUPP;
912 }
913
914 return 0;
915}
916
917static int ems_usb_set_bittiming(struct net_device *netdev)
918{
919 struct ems_usb *dev = netdev_priv(netdev);
920 struct can_bittiming *bt = &dev->can.bittiming;
921 u8 btr0, btr1;
922
923 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
924 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
925 (((bt->phase_seg2 - 1) & 0x7) << 4);
926 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
927 btr1 |= 0x80;
928
aabdfd6a 929 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
702171ad
SH		 930
931 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
932 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
933
934 return ems_usb_command_msg(dev, &dev->active_params);
935}
936
937static void init_params_sja1000(struct ems_cpc_msg *msg)
938{
939 struct cpc_sja1000_params *sja1000 =
940 &msg->msg.can_params.cc_params.sja1000;
941
942 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
943 msg->length = sizeof(struct cpc_can_params);
944 msg->msgid = 0;
945
946 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
947
948 /* Acceptance filter open */
949 sja1000->acc_code0 = 0x00;
950 sja1000->acc_code1 = 0x00;
951 sja1000->acc_code2 = 0x00;
952 sja1000->acc_code3 = 0x00;
953
954 /* Acceptance filter open */
955 sja1000->acc_mask0 = 0xFF;
956 sja1000->acc_mask1 = 0xFF;
957 sja1000->acc_mask2 = 0xFF;
958 sja1000->acc_mask3 = 0xFF;
959
960 sja1000->btr0 = 0;
961 sja1000->btr1 = 0;
962
963 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
964 sja1000->mode = SJA1000_MOD_RM;
965}
966
967/*
968 * probe function for new CPC-USB devices
969 */
970static int ems_usb_probe(struct usb_interface *intf,
971 const struct usb_device_id *id)
972{
973 struct net_device *netdev;
974 struct ems_usb *dev;
975 int i, err = -ENOMEM;
976
a6e4bc53 977 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
702171ad 978 if (!netdev) {
1c0b28b1 979 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
702171ad
SH		 980 return -ENOMEM;
981 }
982
983 dev = netdev_priv(netdev);
984
985 dev->udev = interface_to_usbdev(intf);
986 dev->netdev = netdev;
987
988 dev->can.state = CAN_STATE_STOPPED;
989 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
990 dev->can.bittiming_const = &ems_usb_bittiming_const;
991 dev->can.do_set_bittiming = ems_usb_set_bittiming;
992 dev->can.do_set_mode = ems_usb_set_mode;
ad72c347 993 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
702171ad 994
702171ad
SH		 995 netdev->netdev_ops = &ems_usb_netdev_ops;
996
997 netdev->flags |= IFF_ECHO; /* we support local echo */
998
999 init_usb_anchor(&dev->rx_submitted);
1000
1001 init_usb_anchor(&dev->tx_submitted);
1002 atomic_set(&dev->active_tx_urbs, 0);
1003
1004 for (i = 0; i < MAX_TX_URBS; i++)
1005 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1006
1007 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
87ced2f9 1008 if (!dev->intr_urb)
702171ad 1009 goto cleanup_candev;
702171ad
SH		 1010
1011 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
09da6c5f 1012 if (!dev->intr_in_buffer)
702171ad 1013 goto cleanup_intr_urb;
702171ad
SH		 1014
1015 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1016 sizeof(struct ems_cpc_msg), GFP_KERNEL);
14f8dc49 1017 if (!dev->tx_msg_buffer)
702171ad 1018 goto cleanup_intr_in_buffer;
702171ad
SH		 1019
1020 usb_set_intfdata(intf, dev);
1021
1022 SET_NETDEV_DEV(netdev, &intf->dev);
1023
1024 init_params_sja1000(&dev->active_params);
1025
1026 err = ems_usb_command_msg(dev, &dev->active_params);
1027 if (err) {
aabdfd6a 1028 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
702171ad
SH		 1029 goto cleanup_tx_msg_buffer;
1030 }
1031
1032 err = register_candev(netdev);
1033 if (err) {
aabdfd6a 1034 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
702171ad
SH		 1035 goto cleanup_tx_msg_buffer;
1036 }
1037
1038 return 0;
1039
1040cleanup_tx_msg_buffer:
1041 kfree(dev->tx_msg_buffer);
1042
1043cleanup_intr_in_buffer:
1044 kfree(dev->intr_in_buffer);
1045
1046cleanup_intr_urb:
1047 usb_free_urb(dev->intr_urb);
1048
1049cleanup_candev:
1050 free_candev(netdev);
1051
1052 return err;
1053}
1054
1055/*
1056 * called by the usb core when the device is removed from the system
1057 */
1058static void ems_usb_disconnect(struct usb_interface *intf)
1059{
1060 struct ems_usb *dev = usb_get_intfdata(intf);
1061
1062 usb_set_intfdata(intf, NULL);
1063
1064 if (dev) {
1065 unregister_netdev(dev->netdev);
702171ad
SH		 1066
1067 unlink_all_urbs(dev);
1068
1069 usb_free_urb(dev->intr_urb);
1070
1071 kfree(dev->intr_in_buffer);
72c05f32 1072 kfree(dev->tx_msg_buffer);
ab4a0b8f
PS		 1073
1074 free_candev(dev->netdev);
702171ad
SH		 1075 }
1076}
1077
1078/* usb specific object needed to register this driver with the usb subsystem */
1079static struct usb_driver ems_usb_driver = {
1080 .name = "ems_usb",
1081 .probe = ems_usb_probe,
1082 .disconnect = ems_usb_disconnect,
1083 .id_table = ems_usb_table,
1084};
1085
d632eb1b 1086module_usb_driver(ems_usb_driver);
Linux 6.x block layer and io_uring tree(s)