/drivers/net/can/usb/ems_usb.c

http://github.com/mirrors/linux · C · 1075 lines · 731 code · 237 blank · 107 comment · 96 complexity · 6892da05adaba124597782db7801e859 MD5 · raw file

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