ems_usb.c 27 KB

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