Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2005 Marc Kleine-Budde, Pengutronix |
| 3 | * Copyright (C) 2006 Andrey Volkov, Varma Electronics |
| 4 | * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the version 2 of the GNU General Public License |
| 8 | * as published by the Free Software Foundation |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 | */ |
| 19 | |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/kernel.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 22 | #include <linux/slab.h> |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 23 | #include <linux/netdevice.h> |
| 24 | #include <linux/if_arp.h> |
| 25 | #include <linux/can.h> |
| 26 | #include <linux/can/dev.h> |
| 27 | #include <linux/can/netlink.h> |
| 28 | #include <net/rtnetlink.h> |
| 29 | |
| 30 | #define MOD_DESC "CAN device driver interface" |
| 31 | |
| 32 | MODULE_DESCRIPTION(MOD_DESC); |
| 33 | MODULE_LICENSE("GPL v2"); |
| 34 | MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); |
| 35 | |
| 36 | #ifdef CONFIG_CAN_CALC_BITTIMING |
| 37 | #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */ |
| 38 | |
| 39 | /* |
| 40 | * Bit-timing calculation derived from: |
| 41 | * |
| 42 | * Code based on LinCAN sources and H8S2638 project |
| 43 | * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz |
| 44 | * Copyright 2005 Stanislav Marek |
| 45 | * email: pisa@cmp.felk.cvut.cz |
| 46 | * |
| 47 | * Calculates proper bit-timing parameters for a specified bit-rate |
| 48 | * and sample-point, which can then be used to set the bit-timing |
| 49 | * registers of the CAN controller. You can find more information |
| 50 | * in the header file linux/can/netlink.h. |
| 51 | */ |
| 52 | static int can_update_spt(const struct can_bittiming_const *btc, |
| 53 | int sampl_pt, int tseg, int *tseg1, int *tseg2) |
| 54 | { |
| 55 | *tseg2 = tseg + 1 - (sampl_pt * (tseg + 1)) / 1000; |
| 56 | if (*tseg2 < btc->tseg2_min) |
| 57 | *tseg2 = btc->tseg2_min; |
| 58 | if (*tseg2 > btc->tseg2_max) |
| 59 | *tseg2 = btc->tseg2_max; |
| 60 | *tseg1 = tseg - *tseg2; |
| 61 | if (*tseg1 > btc->tseg1_max) { |
| 62 | *tseg1 = btc->tseg1_max; |
| 63 | *tseg2 = tseg - *tseg1; |
| 64 | } |
| 65 | return 1000 * (tseg + 1 - *tseg2) / (tseg + 1); |
| 66 | } |
| 67 | |
| 68 | static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt) |
| 69 | { |
| 70 | struct can_priv *priv = netdev_priv(dev); |
| 71 | const struct can_bittiming_const *btc = priv->bittiming_const; |
| 72 | long rate, best_rate = 0; |
| 73 | long best_error = 1000000000, error = 0; |
| 74 | int best_tseg = 0, best_brp = 0, brp = 0; |
| 75 | int tsegall, tseg = 0, tseg1 = 0, tseg2 = 0; |
| 76 | int spt_error = 1000, spt = 0, sampl_pt; |
| 77 | u64 v64; |
| 78 | |
| 79 | if (!priv->bittiming_const) |
| 80 | return -ENOTSUPP; |
| 81 | |
| 82 | /* Use CIA recommended sample points */ |
| 83 | if (bt->sample_point) { |
| 84 | sampl_pt = bt->sample_point; |
| 85 | } else { |
| 86 | if (bt->bitrate > 800000) |
| 87 | sampl_pt = 750; |
| 88 | else if (bt->bitrate > 500000) |
| 89 | sampl_pt = 800; |
| 90 | else |
| 91 | sampl_pt = 875; |
| 92 | } |
| 93 | |
| 94 | /* tseg even = round down, odd = round up */ |
| 95 | for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1; |
| 96 | tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) { |
| 97 | tsegall = 1 + tseg / 2; |
| 98 | /* Compute all possible tseg choices (tseg=tseg1+tseg2) */ |
| 99 | brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2; |
| 100 | /* chose brp step which is possible in system */ |
| 101 | brp = (brp / btc->brp_inc) * btc->brp_inc; |
| 102 | if ((brp < btc->brp_min) || (brp > btc->brp_max)) |
| 103 | continue; |
| 104 | rate = priv->clock.freq / (brp * tsegall); |
| 105 | error = bt->bitrate - rate; |
| 106 | /* tseg brp biterror */ |
| 107 | if (error < 0) |
| 108 | error = -error; |
| 109 | if (error > best_error) |
| 110 | continue; |
| 111 | best_error = error; |
| 112 | if (error == 0) { |
| 113 | spt = can_update_spt(btc, sampl_pt, tseg / 2, |
| 114 | &tseg1, &tseg2); |
| 115 | error = sampl_pt - spt; |
| 116 | if (error < 0) |
| 117 | error = -error; |
| 118 | if (error > spt_error) |
| 119 | continue; |
| 120 | spt_error = error; |
| 121 | } |
| 122 | best_tseg = tseg / 2; |
| 123 | best_brp = brp; |
| 124 | best_rate = rate; |
| 125 | if (error == 0) |
| 126 | break; |
| 127 | } |
| 128 | |
| 129 | if (best_error) { |
| 130 | /* Error in one-tenth of a percent */ |
| 131 | error = (best_error * 1000) / bt->bitrate; |
| 132 | if (error > CAN_CALC_MAX_ERROR) { |
| 133 | dev_err(dev->dev.parent, |
| 134 | "bitrate error %ld.%ld%% too high\n", |
| 135 | error / 10, error % 10); |
| 136 | return -EDOM; |
| 137 | } else { |
| 138 | dev_warn(dev->dev.parent, "bitrate error %ld.%ld%%\n", |
| 139 | error / 10, error % 10); |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | /* real sample point */ |
| 144 | bt->sample_point = can_update_spt(btc, sampl_pt, best_tseg, |
| 145 | &tseg1, &tseg2); |
| 146 | |
| 147 | v64 = (u64)best_brp * 1000000000UL; |
| 148 | do_div(v64, priv->clock.freq); |
| 149 | bt->tq = (u32)v64; |
| 150 | bt->prop_seg = tseg1 / 2; |
| 151 | bt->phase_seg1 = tseg1 - bt->prop_seg; |
| 152 | bt->phase_seg2 = tseg2; |
| 153 | bt->sjw = 1; |
| 154 | bt->brp = best_brp; |
| 155 | /* real bit-rate */ |
| 156 | bt->bitrate = priv->clock.freq / (bt->brp * (tseg1 + tseg2 + 1)); |
| 157 | |
| 158 | return 0; |
| 159 | } |
| 160 | #else /* !CONFIG_CAN_CALC_BITTIMING */ |
| 161 | static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt) |
| 162 | { |
| 163 | dev_err(dev->dev.parent, "bit-timing calculation not available\n"); |
| 164 | return -EINVAL; |
| 165 | } |
| 166 | #endif /* CONFIG_CAN_CALC_BITTIMING */ |
| 167 | |
| 168 | /* |
| 169 | * Checks the validity of the specified bit-timing parameters prop_seg, |
| 170 | * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate |
| 171 | * prescaler value brp. You can find more information in the header |
| 172 | * file linux/can/netlink.h. |
| 173 | */ |
| 174 | static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt) |
| 175 | { |
| 176 | struct can_priv *priv = netdev_priv(dev); |
| 177 | const struct can_bittiming_const *btc = priv->bittiming_const; |
| 178 | int tseg1, alltseg; |
| 179 | u64 brp64; |
| 180 | |
| 181 | if (!priv->bittiming_const) |
| 182 | return -ENOTSUPP; |
| 183 | |
| 184 | tseg1 = bt->prop_seg + bt->phase_seg1; |
| 185 | if (!bt->sjw) |
| 186 | bt->sjw = 1; |
| 187 | if (bt->sjw > btc->sjw_max || |
| 188 | tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || |
| 189 | bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) |
| 190 | return -ERANGE; |
| 191 | |
| 192 | brp64 = (u64)priv->clock.freq * (u64)bt->tq; |
| 193 | if (btc->brp_inc > 1) |
| 194 | do_div(brp64, btc->brp_inc); |
| 195 | brp64 += 500000000UL - 1; |
| 196 | do_div(brp64, 1000000000UL); /* the practicable BRP */ |
| 197 | if (btc->brp_inc > 1) |
| 198 | brp64 *= btc->brp_inc; |
| 199 | bt->brp = (u32)brp64; |
| 200 | |
| 201 | if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) |
| 202 | return -EINVAL; |
| 203 | |
| 204 | alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1; |
| 205 | bt->bitrate = priv->clock.freq / (bt->brp * alltseg); |
| 206 | bt->sample_point = ((tseg1 + 1) * 1000) / alltseg; |
| 207 | |
| 208 | return 0; |
| 209 | } |
| 210 | |
| 211 | int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt) |
| 212 | { |
| 213 | struct can_priv *priv = netdev_priv(dev); |
| 214 | int err; |
| 215 | |
| 216 | /* Check if the CAN device has bit-timing parameters */ |
| 217 | if (priv->bittiming_const) { |
| 218 | |
| 219 | /* Non-expert mode? Check if the bitrate has been pre-defined */ |
| 220 | if (!bt->tq) |
| 221 | /* Determine bit-timing parameters */ |
| 222 | err = can_calc_bittiming(dev, bt); |
| 223 | else |
| 224 | /* Check bit-timing params and calculate proper brp */ |
| 225 | err = can_fixup_bittiming(dev, bt); |
| 226 | if (err) |
| 227 | return err; |
| 228 | } |
| 229 | |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | /* |
| 234 | * Local echo of CAN messages |
| 235 | * |
| 236 | * CAN network devices *should* support a local echo functionality |
| 237 | * (see Documentation/networking/can.txt). To test the handling of CAN |
| 238 | * interfaces that do not support the local echo both driver types are |
| 239 | * implemented. In the case that the driver does not support the echo |
| 240 | * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core |
| 241 | * to perform the echo as a fallback solution. |
| 242 | */ |
| 243 | static void can_flush_echo_skb(struct net_device *dev) |
| 244 | { |
| 245 | struct can_priv *priv = netdev_priv(dev); |
| 246 | struct net_device_stats *stats = &dev->stats; |
| 247 | int i; |
| 248 | |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 249 | for (i = 0; i < priv->echo_skb_max; i++) { |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 250 | if (priv->echo_skb[i]) { |
| 251 | kfree_skb(priv->echo_skb[i]); |
| 252 | priv->echo_skb[i] = NULL; |
| 253 | stats->tx_dropped++; |
| 254 | stats->tx_aborted_errors++; |
| 255 | } |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | /* |
| 260 | * Put the skb on the stack to be looped backed locally lateron |
| 261 | * |
| 262 | * The function is typically called in the start_xmit function |
| 263 | * of the device driver. The driver must protect access to |
| 264 | * priv->echo_skb, if necessary. |
| 265 | */ |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 266 | void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, |
| 267 | unsigned int idx) |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 268 | { |
| 269 | struct can_priv *priv = netdev_priv(dev); |
| 270 | |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 271 | BUG_ON(idx >= priv->echo_skb_max); |
| 272 | |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 273 | /* check flag whether this packet has to be looped back */ |
| 274 | if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK) { |
| 275 | kfree_skb(skb); |
| 276 | return; |
| 277 | } |
| 278 | |
| 279 | if (!priv->echo_skb[idx]) { |
| 280 | struct sock *srcsk = skb->sk; |
| 281 | |
| 282 | if (atomic_read(&skb->users) != 1) { |
| 283 | struct sk_buff *old_skb = skb; |
| 284 | |
| 285 | skb = skb_clone(old_skb, GFP_ATOMIC); |
| 286 | kfree_skb(old_skb); |
| 287 | if (!skb) |
| 288 | return; |
| 289 | } else |
| 290 | skb_orphan(skb); |
| 291 | |
| 292 | skb->sk = srcsk; |
| 293 | |
| 294 | /* make settings for echo to reduce code in irq context */ |
| 295 | skb->protocol = htons(ETH_P_CAN); |
| 296 | skb->pkt_type = PACKET_BROADCAST; |
| 297 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 298 | skb->dev = dev; |
| 299 | |
| 300 | /* save this skb for tx interrupt echo handling */ |
| 301 | priv->echo_skb[idx] = skb; |
| 302 | } else { |
| 303 | /* locking problem with netif_stop_queue() ?? */ |
| 304 | dev_err(dev->dev.parent, "%s: BUG! echo_skb is occupied!\n", |
| 305 | __func__); |
| 306 | kfree_skb(skb); |
| 307 | } |
| 308 | } |
| 309 | EXPORT_SYMBOL_GPL(can_put_echo_skb); |
| 310 | |
| 311 | /* |
| 312 | * Get the skb from the stack and loop it back locally |
| 313 | * |
| 314 | * The function is typically called when the TX done interrupt |
| 315 | * is handled in the device driver. The driver must protect |
| 316 | * access to priv->echo_skb, if necessary. |
| 317 | */ |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 318 | void can_get_echo_skb(struct net_device *dev, unsigned int idx) |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 319 | { |
| 320 | struct can_priv *priv = netdev_priv(dev); |
| 321 | |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 322 | BUG_ON(idx >= priv->echo_skb_max); |
| 323 | |
Wolfgang Grandegger | 39e3ab6 | 2009-09-01 05:26:12 +0000 | [diff] [blame] | 324 | if (priv->echo_skb[idx]) { |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 325 | netif_rx(priv->echo_skb[idx]); |
| 326 | priv->echo_skb[idx] = NULL; |
| 327 | } |
| 328 | } |
| 329 | EXPORT_SYMBOL_GPL(can_get_echo_skb); |
| 330 | |
| 331 | /* |
Wolfgang Grandegger | 39e3ab6 | 2009-09-01 05:26:12 +0000 | [diff] [blame] | 332 | * Remove the skb from the stack and free it. |
| 333 | * |
| 334 | * The function is typically called when TX failed. |
| 335 | */ |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 336 | void can_free_echo_skb(struct net_device *dev, unsigned int idx) |
Wolfgang Grandegger | 39e3ab6 | 2009-09-01 05:26:12 +0000 | [diff] [blame] | 337 | { |
| 338 | struct can_priv *priv = netdev_priv(dev); |
| 339 | |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 340 | BUG_ON(idx >= priv->echo_skb_max); |
| 341 | |
Wolfgang Grandegger | 39e3ab6 | 2009-09-01 05:26:12 +0000 | [diff] [blame] | 342 | if (priv->echo_skb[idx]) { |
| 343 | kfree_skb(priv->echo_skb[idx]); |
| 344 | priv->echo_skb[idx] = NULL; |
| 345 | } |
| 346 | } |
| 347 | EXPORT_SYMBOL_GPL(can_free_echo_skb); |
| 348 | |
| 349 | /* |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 350 | * CAN device restart for bus-off recovery |
| 351 | */ |
| 352 | void can_restart(unsigned long data) |
| 353 | { |
| 354 | struct net_device *dev = (struct net_device *)data; |
| 355 | struct can_priv *priv = netdev_priv(dev); |
| 356 | struct net_device_stats *stats = &dev->stats; |
| 357 | struct sk_buff *skb; |
| 358 | struct can_frame *cf; |
| 359 | int err; |
| 360 | |
| 361 | BUG_ON(netif_carrier_ok(dev)); |
| 362 | |
| 363 | /* |
| 364 | * No synchronization needed because the device is bus-off and |
| 365 | * no messages can come in or go out. |
| 366 | */ |
| 367 | can_flush_echo_skb(dev); |
| 368 | |
| 369 | /* send restart message upstream */ |
Wolfgang Grandegger | 7b6856a | 2009-10-20 00:08:01 -0700 | [diff] [blame] | 370 | skb = alloc_can_err_skb(dev, &cf); |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 371 | if (skb == NULL) { |
| 372 | err = -ENOMEM; |
Wolfgang Grandegger | b3d0df7 | 2009-07-20 04:06:40 +0000 | [diff] [blame] | 373 | goto restart; |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 374 | } |
Wolfgang Grandegger | 7b6856a | 2009-10-20 00:08:01 -0700 | [diff] [blame] | 375 | cf->can_id |= CAN_ERR_RESTARTED; |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 376 | |
| 377 | netif_rx(skb); |
| 378 | |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 379 | stats->rx_packets++; |
| 380 | stats->rx_bytes += cf->can_dlc; |
| 381 | |
Wolfgang Grandegger | b3d0df7 | 2009-07-20 04:06:40 +0000 | [diff] [blame] | 382 | restart: |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 383 | dev_dbg(dev->dev.parent, "restarted\n"); |
| 384 | priv->can_stats.restarts++; |
| 385 | |
| 386 | /* Now restart the device */ |
| 387 | err = priv->do_set_mode(dev, CAN_MODE_START); |
| 388 | |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 389 | netif_carrier_on(dev); |
| 390 | if (err) |
| 391 | dev_err(dev->dev.parent, "Error %d during restart", err); |
| 392 | } |
| 393 | |
| 394 | int can_restart_now(struct net_device *dev) |
| 395 | { |
| 396 | struct can_priv *priv = netdev_priv(dev); |
| 397 | |
| 398 | /* |
| 399 | * A manual restart is only permitted if automatic restart is |
| 400 | * disabled and the device is in the bus-off state |
| 401 | */ |
| 402 | if (priv->restart_ms) |
| 403 | return -EINVAL; |
| 404 | if (priv->state != CAN_STATE_BUS_OFF) |
| 405 | return -EBUSY; |
| 406 | |
| 407 | /* Runs as soon as possible in the timer context */ |
| 408 | mod_timer(&priv->restart_timer, jiffies); |
| 409 | |
| 410 | return 0; |
| 411 | } |
| 412 | |
| 413 | /* |
| 414 | * CAN bus-off |
| 415 | * |
| 416 | * This functions should be called when the device goes bus-off to |
| 417 | * tell the netif layer that no more packets can be sent or received. |
| 418 | * If enabled, a timer is started to trigger bus-off recovery. |
| 419 | */ |
| 420 | void can_bus_off(struct net_device *dev) |
| 421 | { |
| 422 | struct can_priv *priv = netdev_priv(dev); |
| 423 | |
| 424 | dev_dbg(dev->dev.parent, "bus-off\n"); |
| 425 | |
| 426 | netif_carrier_off(dev); |
| 427 | priv->can_stats.bus_off++; |
| 428 | |
| 429 | if (priv->restart_ms) |
| 430 | mod_timer(&priv->restart_timer, |
| 431 | jiffies + (priv->restart_ms * HZ) / 1000); |
| 432 | } |
| 433 | EXPORT_SYMBOL_GPL(can_bus_off); |
| 434 | |
| 435 | static void can_setup(struct net_device *dev) |
| 436 | { |
| 437 | dev->type = ARPHRD_CAN; |
| 438 | dev->mtu = sizeof(struct can_frame); |
| 439 | dev->hard_header_len = 0; |
| 440 | dev->addr_len = 0; |
| 441 | dev->tx_queue_len = 10; |
| 442 | |
| 443 | /* New-style flags. */ |
| 444 | dev->flags = IFF_NOARP; |
| 445 | dev->features = NETIF_F_NO_CSUM; |
| 446 | } |
| 447 | |
Wolfgang Grandegger | 7b6856a | 2009-10-20 00:08:01 -0700 | [diff] [blame] | 448 | struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) |
| 449 | { |
| 450 | struct sk_buff *skb; |
| 451 | |
| 452 | skb = netdev_alloc_skb(dev, sizeof(struct can_frame)); |
| 453 | if (unlikely(!skb)) |
| 454 | return NULL; |
| 455 | |
| 456 | skb->protocol = htons(ETH_P_CAN); |
| 457 | skb->pkt_type = PACKET_BROADCAST; |
| 458 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 459 | *cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); |
| 460 | memset(*cf, 0, sizeof(struct can_frame)); |
| 461 | |
| 462 | return skb; |
| 463 | } |
| 464 | EXPORT_SYMBOL_GPL(alloc_can_skb); |
| 465 | |
| 466 | struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) |
| 467 | { |
| 468 | struct sk_buff *skb; |
| 469 | |
| 470 | skb = alloc_can_skb(dev, cf); |
| 471 | if (unlikely(!skb)) |
| 472 | return NULL; |
| 473 | |
| 474 | (*cf)->can_id = CAN_ERR_FLAG; |
| 475 | (*cf)->can_dlc = CAN_ERR_DLC; |
| 476 | |
| 477 | return skb; |
| 478 | } |
| 479 | EXPORT_SYMBOL_GPL(alloc_can_err_skb); |
| 480 | |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 481 | /* |
| 482 | * Allocate and setup space for the CAN network device |
| 483 | */ |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 484 | struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max) |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 485 | { |
| 486 | struct net_device *dev; |
| 487 | struct can_priv *priv; |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 488 | int size; |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 489 | |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 490 | if (echo_skb_max) |
| 491 | size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + |
| 492 | echo_skb_max * sizeof(struct sk_buff *); |
| 493 | else |
| 494 | size = sizeof_priv; |
| 495 | |
| 496 | dev = alloc_netdev(size, "can%d", can_setup); |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 497 | if (!dev) |
| 498 | return NULL; |
| 499 | |
| 500 | priv = netdev_priv(dev); |
| 501 | |
Wolfgang Grandegger | a6e4bc5 | 2009-10-08 22:17:11 +0000 | [diff] [blame] | 502 | if (echo_skb_max) { |
| 503 | priv->echo_skb_max = echo_skb_max; |
| 504 | priv->echo_skb = (void *)priv + |
| 505 | ALIGN(sizeof_priv, sizeof(struct sk_buff *)); |
| 506 | } |
| 507 | |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 508 | priv->state = CAN_STATE_STOPPED; |
| 509 | |
| 510 | init_timer(&priv->restart_timer); |
| 511 | |
| 512 | return dev; |
| 513 | } |
| 514 | EXPORT_SYMBOL_GPL(alloc_candev); |
| 515 | |
| 516 | /* |
| 517 | * Free space of the CAN network device |
| 518 | */ |
| 519 | void free_candev(struct net_device *dev) |
| 520 | { |
| 521 | free_netdev(dev); |
| 522 | } |
| 523 | EXPORT_SYMBOL_GPL(free_candev); |
| 524 | |
| 525 | /* |
| 526 | * Common open function when the device gets opened. |
| 527 | * |
| 528 | * This function should be called in the open function of the device |
| 529 | * driver. |
| 530 | */ |
| 531 | int open_candev(struct net_device *dev) |
| 532 | { |
| 533 | struct can_priv *priv = netdev_priv(dev); |
| 534 | |
| 535 | if (!priv->bittiming.tq && !priv->bittiming.bitrate) { |
| 536 | dev_err(dev->dev.parent, "bit-timing not yet defined\n"); |
| 537 | return -EINVAL; |
| 538 | } |
| 539 | |
Wolfgang Grandegger | 1b0d922 | 2009-07-20 04:06:41 +0000 | [diff] [blame] | 540 | /* Switch carrier on if device was stopped while in bus-off state */ |
| 541 | if (!netif_carrier_ok(dev)) |
| 542 | netif_carrier_on(dev); |
| 543 | |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 544 | setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev); |
| 545 | |
| 546 | return 0; |
| 547 | } |
Wolfgang Grandegger | 128ced8 | 2009-05-30 07:55:48 +0000 | [diff] [blame] | 548 | EXPORT_SYMBOL_GPL(open_candev); |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 549 | |
| 550 | /* |
| 551 | * Common close function for cleanup before the device gets closed. |
| 552 | * |
| 553 | * This function should be called in the close function of the device |
| 554 | * driver. |
| 555 | */ |
| 556 | void close_candev(struct net_device *dev) |
| 557 | { |
| 558 | struct can_priv *priv = netdev_priv(dev); |
| 559 | |
| 560 | if (del_timer_sync(&priv->restart_timer)) |
| 561 | dev_put(dev); |
| 562 | can_flush_echo_skb(dev); |
| 563 | } |
| 564 | EXPORT_SYMBOL_GPL(close_candev); |
| 565 | |
| 566 | /* |
| 567 | * CAN netlink interface |
| 568 | */ |
| 569 | static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { |
| 570 | [IFLA_CAN_STATE] = { .type = NLA_U32 }, |
| 571 | [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, |
| 572 | [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, |
| 573 | [IFLA_CAN_RESTART] = { .type = NLA_U32 }, |
| 574 | [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, |
| 575 | [IFLA_CAN_BITTIMING_CONST] |
| 576 | = { .len = sizeof(struct can_bittiming_const) }, |
| 577 | [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, |
Wolfgang Grandegger | 52c793f | 2010-02-22 22:21:17 +0000 | [diff] [blame] | 578 | [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 579 | }; |
| 580 | |
| 581 | static int can_changelink(struct net_device *dev, |
| 582 | struct nlattr *tb[], struct nlattr *data[]) |
| 583 | { |
| 584 | struct can_priv *priv = netdev_priv(dev); |
| 585 | int err; |
| 586 | |
| 587 | /* We need synchronization with dev->stop() */ |
| 588 | ASSERT_RTNL(); |
| 589 | |
| 590 | if (data[IFLA_CAN_CTRLMODE]) { |
| 591 | struct can_ctrlmode *cm; |
| 592 | |
| 593 | /* Do not allow changing controller mode while running */ |
| 594 | if (dev->flags & IFF_UP) |
| 595 | return -EBUSY; |
| 596 | cm = nla_data(data[IFLA_CAN_CTRLMODE]); |
Christian Pellegrin | ad72c34 | 2010-01-14 07:08:34 +0000 | [diff] [blame] | 597 | if (cm->flags & ~priv->ctrlmode_supported) |
| 598 | return -EOPNOTSUPP; |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 599 | priv->ctrlmode &= ~cm->mask; |
| 600 | priv->ctrlmode |= cm->flags; |
| 601 | } |
| 602 | |
| 603 | if (data[IFLA_CAN_BITTIMING]) { |
| 604 | struct can_bittiming bt; |
| 605 | |
| 606 | /* Do not allow changing bittiming while running */ |
| 607 | if (dev->flags & IFF_UP) |
| 608 | return -EBUSY; |
| 609 | memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); |
| 610 | if ((!bt.bitrate && !bt.tq) || (bt.bitrate && bt.tq)) |
| 611 | return -EINVAL; |
| 612 | err = can_get_bittiming(dev, &bt); |
| 613 | if (err) |
| 614 | return err; |
| 615 | memcpy(&priv->bittiming, &bt, sizeof(bt)); |
| 616 | |
| 617 | if (priv->do_set_bittiming) { |
| 618 | /* Finally, set the bit-timing registers */ |
| 619 | err = priv->do_set_bittiming(dev); |
| 620 | if (err) |
| 621 | return err; |
| 622 | } |
| 623 | } |
| 624 | |
| 625 | if (data[IFLA_CAN_RESTART_MS]) { |
| 626 | /* Do not allow changing restart delay while running */ |
| 627 | if (dev->flags & IFF_UP) |
| 628 | return -EBUSY; |
| 629 | priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); |
| 630 | } |
| 631 | |
| 632 | if (data[IFLA_CAN_RESTART]) { |
| 633 | /* Do not allow a restart while not running */ |
| 634 | if (!(dev->flags & IFF_UP)) |
| 635 | return -EINVAL; |
| 636 | err = can_restart_now(dev); |
| 637 | if (err) |
| 638 | return err; |
| 639 | } |
| 640 | |
| 641 | return 0; |
| 642 | } |
| 643 | |
Wolfgang Grandegger | 53a0ef86 | 2009-11-06 23:53:13 +0000 | [diff] [blame] | 644 | static size_t can_get_size(const struct net_device *dev) |
| 645 | { |
| 646 | struct can_priv *priv = netdev_priv(dev); |
| 647 | size_t size; |
| 648 | |
| 649 | size = nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ |
| 650 | size += sizeof(struct can_ctrlmode); /* IFLA_CAN_CTRLMODE */ |
| 651 | size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ |
| 652 | size += sizeof(struct can_bittiming); /* IFLA_CAN_BITTIMING */ |
| 653 | size += sizeof(struct can_clock); /* IFLA_CAN_CLOCK */ |
Wolfgang Grandegger | 52c793f | 2010-02-22 22:21:17 +0000 | [diff] [blame] | 654 | if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ |
| 655 | size += sizeof(struct can_berr_counter); |
Wolfgang Grandegger | 53a0ef86 | 2009-11-06 23:53:13 +0000 | [diff] [blame] | 656 | if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ |
| 657 | size += sizeof(struct can_bittiming_const); |
| 658 | |
| 659 | return size; |
| 660 | } |
| 661 | |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 662 | static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) |
| 663 | { |
| 664 | struct can_priv *priv = netdev_priv(dev); |
| 665 | struct can_ctrlmode cm = {.flags = priv->ctrlmode}; |
Wolfgang Grandegger | 52c793f | 2010-02-22 22:21:17 +0000 | [diff] [blame] | 666 | struct can_berr_counter bec; |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 667 | enum can_state state = priv->state; |
| 668 | |
| 669 | if (priv->do_get_state) |
| 670 | priv->do_get_state(dev, &state); |
| 671 | NLA_PUT_U32(skb, IFLA_CAN_STATE, state); |
| 672 | NLA_PUT(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm); |
| 673 | NLA_PUT_U32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms); |
| 674 | NLA_PUT(skb, IFLA_CAN_BITTIMING, |
| 675 | sizeof(priv->bittiming), &priv->bittiming); |
| 676 | NLA_PUT(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock); |
Wolfgang Grandegger | 52c793f | 2010-02-22 22:21:17 +0000 | [diff] [blame] | 677 | if (priv->do_get_berr_counter && !priv->do_get_berr_counter(dev, &bec)) |
| 678 | NLA_PUT(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec); |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 679 | if (priv->bittiming_const) |
| 680 | NLA_PUT(skb, IFLA_CAN_BITTIMING_CONST, |
| 681 | sizeof(*priv->bittiming_const), priv->bittiming_const); |
| 682 | |
| 683 | return 0; |
| 684 | |
| 685 | nla_put_failure: |
| 686 | return -EMSGSIZE; |
| 687 | } |
| 688 | |
Wolfgang Grandegger | 55369c0 | 2009-11-12 05:34:05 +0000 | [diff] [blame] | 689 | static size_t can_get_xstats_size(const struct net_device *dev) |
| 690 | { |
| 691 | return sizeof(struct can_device_stats); |
| 692 | } |
| 693 | |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 694 | static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) |
| 695 | { |
| 696 | struct can_priv *priv = netdev_priv(dev); |
| 697 | |
| 698 | NLA_PUT(skb, IFLA_INFO_XSTATS, |
| 699 | sizeof(priv->can_stats), &priv->can_stats); |
| 700 | |
| 701 | return 0; |
| 702 | |
| 703 | nla_put_failure: |
| 704 | return -EMSGSIZE; |
| 705 | } |
| 706 | |
Eric W. Biederman | 81adee4 | 2009-11-08 00:53:51 -0800 | [diff] [blame] | 707 | static int can_newlink(struct net *src_net, struct net_device *dev, |
Oliver Hartkopp | 993e6f2 | 2009-08-11 02:41:24 +0000 | [diff] [blame] | 708 | struct nlattr *tb[], struct nlattr *data[]) |
| 709 | { |
| 710 | return -EOPNOTSUPP; |
| 711 | } |
| 712 | |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 713 | static struct rtnl_link_ops can_link_ops __read_mostly = { |
| 714 | .kind = "can", |
| 715 | .maxtype = IFLA_CAN_MAX, |
| 716 | .policy = can_policy, |
| 717 | .setup = can_setup, |
Oliver Hartkopp | 993e6f2 | 2009-08-11 02:41:24 +0000 | [diff] [blame] | 718 | .newlink = can_newlink, |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 719 | .changelink = can_changelink, |
Wolfgang Grandegger | 53a0ef86 | 2009-11-06 23:53:13 +0000 | [diff] [blame] | 720 | .get_size = can_get_size, |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 721 | .fill_info = can_fill_info, |
Wolfgang Grandegger | 55369c0 | 2009-11-12 05:34:05 +0000 | [diff] [blame] | 722 | .get_xstats_size = can_get_xstats_size, |
Wolfgang Grandegger | 39549ee | 2009-05-15 23:39:29 +0000 | [diff] [blame] | 723 | .fill_xstats = can_fill_xstats, |
| 724 | }; |
| 725 | |
| 726 | /* |
| 727 | * Register the CAN network device |
| 728 | */ |
| 729 | int register_candev(struct net_device *dev) |
| 730 | { |
| 731 | dev->rtnl_link_ops = &can_link_ops; |
| 732 | return register_netdev(dev); |
| 733 | } |
| 734 | EXPORT_SYMBOL_GPL(register_candev); |
| 735 | |
| 736 | /* |
| 737 | * Unregister the CAN network device |
| 738 | */ |
| 739 | void unregister_candev(struct net_device *dev) |
| 740 | { |
| 741 | unregister_netdev(dev); |
| 742 | } |
| 743 | EXPORT_SYMBOL_GPL(unregister_candev); |
| 744 | |
| 745 | static __init int can_dev_init(void) |
| 746 | { |
| 747 | int err; |
| 748 | |
| 749 | err = rtnl_link_register(&can_link_ops); |
| 750 | if (!err) |
| 751 | printk(KERN_INFO MOD_DESC "\n"); |
| 752 | |
| 753 | return err; |
| 754 | } |
| 755 | module_init(can_dev_init); |
| 756 | |
| 757 | static __exit void can_dev_exit(void) |
| 758 | { |
| 759 | rtnl_link_unregister(&can_link_ops); |
| 760 | } |
| 761 | module_exit(can_dev_exit); |
| 762 | |
| 763 | MODULE_ALIAS_RTNL_LINK("can"); |