// SPDX-License-Identifier: GPL-2.0-only /* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix * Copyright (C) 2006 Andrey Volkov, Varma Electronics * Copyright (C) 2008-2009 Wolfgang Grandegger */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define MOD_DESC "CAN device driver interface" MODULE_DESCRIPTION(MOD_DESC); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Wolfgang Grandegger "); /* CAN DLC to real data length conversion helpers */ static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 12, 16, 20, 24, 32, 48, 64}; /* get data length from can_dlc with sanitized can_dlc */ u8 can_dlc2len(u8 can_dlc) { return dlc2len[can_dlc & 0x0F]; } EXPORT_SYMBOL_GPL(can_dlc2len); static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */ 9, 9, 9, 9, /* 9 - 12 */ 10, 10, 10, 10, /* 13 - 16 */ 11, 11, 11, 11, /* 17 - 20 */ 12, 12, 12, 12, /* 21 - 24 */ 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */ 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */ 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */ 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */ 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */ /* map the sanitized data length to an appropriate data length code */ u8 can_len2dlc(u8 len) { if (unlikely(len > 64)) return 0xF; return len2dlc[len]; } EXPORT_SYMBOL_GPL(can_len2dlc); #ifdef CONFIG_CAN_CALC_BITTIMING #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */ #define CAN_CALC_SYNC_SEG 1 /* Bit-timing calculation derived from: * * Code based on LinCAN sources and H8S2638 project * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz * Copyright 2005 Stanislav Marek * email: pisa@cmp.felk.cvut.cz * * Calculates proper bit-timing parameters for a specified bit-rate * and sample-point, which can then be used to set the bit-timing * registers of the CAN controller. You can find more information * in the header file linux/can/netlink.h. */ static int can_update_sample_point(const struct can_bittiming_const *btc, unsigned int sample_point_nominal, unsigned int tseg, unsigned int *tseg1_ptr, unsigned int *tseg2_ptr, unsigned int *sample_point_error_ptr) { unsigned int sample_point_error, best_sample_point_error = UINT_MAX; unsigned int sample_point, best_sample_point = 0; unsigned int tseg1, tseg2; int i; for (i = 0; i <= 1; i++) { tseg2 = tseg + CAN_CALC_SYNC_SEG - (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) / 1000 - i; tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max); tseg1 = tseg - tseg2; if (tseg1 > btc->tseg1_max) { tseg1 = btc->tseg1_max; tseg2 = tseg - tseg1; } sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) / (tseg + CAN_CALC_SYNC_SEG); sample_point_error = abs(sample_point_nominal - sample_point); if (sample_point <= sample_point_nominal && sample_point_error < best_sample_point_error) { best_sample_point = sample_point; best_sample_point_error = sample_point_error; *tseg1_ptr = tseg1; *tseg2_ptr = tseg2; } } if (sample_point_error_ptr) *sample_point_error_ptr = best_sample_point_error; return best_sample_point; } static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, const struct can_bittiming_const *btc) { struct can_priv *priv = netdev_priv(dev); unsigned int bitrate; /* current bitrate */ unsigned int bitrate_error; /* difference between current and nominal value */ unsigned int best_bitrate_error = UINT_MAX; unsigned int sample_point_error; /* difference between current and nominal value */ unsigned int best_sample_point_error = UINT_MAX; unsigned int sample_point_nominal; /* nominal sample point */ unsigned int best_tseg = 0; /* current best value for tseg */ unsigned int best_brp = 0; /* current best value for brp */ unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0; u64 v64; /* Use CiA recommended sample points */ if (bt->sample_point) { sample_point_nominal = bt->sample_point; } else { if (bt->bitrate > 800000) sample_point_nominal = 750; else if (bt->bitrate > 500000) sample_point_nominal = 800; else sample_point_nominal = 875; } /* tseg even = round down, odd = round up */ for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1; tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) { tsegall = CAN_CALC_SYNC_SEG + tseg / 2; /* Compute all possible tseg choices (tseg=tseg1+tseg2) */ brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2; /* choose brp step which is possible in system */ brp = (brp / btc->brp_inc) * btc->brp_inc; if (brp < btc->brp_min || brp > btc->brp_max) continue; bitrate = priv->clock.freq / (brp * tsegall); bitrate_error = abs(bt->bitrate - bitrate); /* tseg brp biterror */ if (bitrate_error > best_bitrate_error) continue; /* reset sample point error if we have a better bitrate */ if (bitrate_error < best_bitrate_error) best_sample_point_error = UINT_MAX; can_update_sample_point(btc, sample_point_nominal, tseg / 2, &tseg1, &tseg2, &sample_point_error); if (sample_point_error > best_sample_point_error) continue; best_sample_point_error = sample_point_error; best_bitrate_error = bitrate_error; best_tseg = tseg / 2; best_brp = brp; if (bitrate_error == 0 && sample_point_error == 0) break; } if (best_bitrate_error) { /* Error in one-tenth of a percent */ v64 = (u64)best_bitrate_error * 1000; do_div(v64, bt->bitrate); bitrate_error = (u32)v64; if (bitrate_error > CAN_CALC_MAX_ERROR) { netdev_err(dev, "bitrate error %d.%d%% too high\n", bitrate_error / 10, bitrate_error % 10); return -EDOM; } netdev_warn(dev, "bitrate error %d.%d%%\n", bitrate_error / 10, bitrate_error % 10); } /* real sample point */ bt->sample_point = can_update_sample_point(btc, sample_point_nominal, best_tseg, &tseg1, &tseg2, NULL); v64 = (u64)best_brp * 1000 * 1000 * 1000; do_div(v64, priv->clock.freq); bt->tq = (u32)v64; bt->prop_seg = tseg1 / 2; bt->phase_seg1 = tseg1 - bt->prop_seg; bt->phase_seg2 = tseg2; /* check for sjw user settings */ if (!bt->sjw || !btc->sjw_max) { bt->sjw = 1; } else { /* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */ if (bt->sjw > btc->sjw_max) bt->sjw = btc->sjw_max; /* bt->sjw must not be higher than tseg2 */ if (tseg2 < bt->sjw) bt->sjw = tseg2; } bt->brp = best_brp; /* real bitrate */ bt->bitrate = priv->clock.freq / (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2)); return 0; } #else /* !CONFIG_CAN_CALC_BITTIMING */ static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, const struct can_bittiming_const *btc) { netdev_err(dev, "bit-timing calculation not available\n"); return -EINVAL; } #endif /* CONFIG_CAN_CALC_BITTIMING */ /* Checks the validity of the specified bit-timing parameters prop_seg, * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate * prescaler value brp. You can find more information in the header * file linux/can/netlink.h. */ static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt, const struct can_bittiming_const *btc) { struct can_priv *priv = netdev_priv(dev); int tseg1, alltseg; u64 brp64; tseg1 = bt->prop_seg + bt->phase_seg1; if (!bt->sjw) bt->sjw = 1; if (bt->sjw > btc->sjw_max || tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) return -ERANGE; brp64 = (u64)priv->clock.freq * (u64)bt->tq; if (btc->brp_inc > 1) do_div(brp64, btc->brp_inc); brp64 += 500000000UL - 1; do_div(brp64, 1000000000UL); /* the practicable BRP */ if (btc->brp_inc > 1) brp64 *= btc->brp_inc; bt->brp = (u32)brp64; if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) return -EINVAL; alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1; bt->bitrate = priv->clock.freq / (bt->brp * alltseg); bt->sample_point = ((tseg1 + 1) * 1000) / alltseg; return 0; } /* Checks the validity of predefined bitrate settings */ static int can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt, const u32 *bitrate_const, const unsigned int bitrate_const_cnt) { struct can_priv *priv = netdev_priv(dev); unsigned int i; for (i = 0; i < bitrate_const_cnt; i++) { if (bt->bitrate == bitrate_const[i]) break; } if (i >= priv->bitrate_const_cnt) return -EINVAL; return 0; } static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt, const struct can_bittiming_const *btc, const u32 *bitrate_const, const unsigned int bitrate_const_cnt) { int err; /* Depending on the given can_bittiming parameter structure the CAN * timing parameters are calculated based on the provided bitrate OR * alternatively the CAN timing parameters (tq, prop_seg, etc.) are * provided directly which are then checked and fixed up. */ if (!bt->tq && bt->bitrate && btc) err = can_calc_bittiming(dev, bt, btc); else if (bt->tq && !bt->bitrate && btc) err = can_fixup_bittiming(dev, bt, btc); else if (!bt->tq && bt->bitrate && bitrate_const) err = can_validate_bitrate(dev, bt, bitrate_const, bitrate_const_cnt); else err = -EINVAL; return err; } static void can_update_state_error_stats(struct net_device *dev, enum can_state new_state) { struct can_priv *priv = netdev_priv(dev); if (new_state <= priv->state) return; switch (new_state) { case CAN_STATE_ERROR_WARNING: priv->can_stats.error_warning++; break; case CAN_STATE_ERROR_PASSIVE: priv->can_stats.error_passive++; break; case CAN_STATE_BUS_OFF: priv->can_stats.bus_off++; break; default: break; } } static int can_tx_state_to_frame(struct net_device *dev, enum can_state state) { switch (state) { case CAN_STATE_ERROR_ACTIVE: return CAN_ERR_CRTL_ACTIVE; case CAN_STATE_ERROR_WARNING: return CAN_ERR_CRTL_TX_WARNING; case CAN_STATE_ERROR_PASSIVE: return CAN_ERR_CRTL_TX_PASSIVE; default: return 0; } } static int can_rx_state_to_frame(struct net_device *dev, enum can_state state) { switch (state) { case CAN_STATE_ERROR_ACTIVE: return CAN_ERR_CRTL_ACTIVE; case CAN_STATE_ERROR_WARNING: return CAN_ERR_CRTL_RX_WARNING; case CAN_STATE_ERROR_PASSIVE: return CAN_ERR_CRTL_RX_PASSIVE; default: return 0; } } void can_change_state(struct net_device *dev, struct can_frame *cf, enum can_state tx_state, enum can_state rx_state) { struct can_priv *priv = netdev_priv(dev); enum can_state new_state = max(tx_state, rx_state); if (unlikely(new_state == priv->state)) { netdev_warn(dev, "%s: oops, state did not change", __func__); return; } netdev_dbg(dev, "New error state: %d\n", new_state); can_update_state_error_stats(dev, new_state); priv->state = new_state; if (!cf) return; if (unlikely(new_state == CAN_STATE_BUS_OFF)) { cf->can_id |= CAN_ERR_BUSOFF; return; } cf->can_id |= CAN_ERR_CRTL; cf->data[1] |= tx_state >= rx_state ? can_tx_state_to_frame(dev, tx_state) : 0; cf->data[1] |= tx_state <= rx_state ? can_rx_state_to_frame(dev, rx_state) : 0; } EXPORT_SYMBOL_GPL(can_change_state); /* Local echo of CAN messages * * CAN network devices *should* support a local echo functionality * (see Documentation/networking/can.rst). To test the handling of CAN * interfaces that do not support the local echo both driver types are * implemented. In the case that the driver does not support the echo * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core * to perform the echo as a fallback solution. */ static void can_flush_echo_skb(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; int i; for (i = 0; i < priv->echo_skb_max; i++) { if (priv->echo_skb[i]) { kfree_skb(priv->echo_skb[i]); priv->echo_skb[i] = NULL; stats->tx_dropped++; stats->tx_aborted_errors++; } } } /* Put the skb on the stack to be looped backed locally lateron * * The function is typically called in the start_xmit function * of the device driver. The driver must protect access to * priv->echo_skb, if necessary. */ void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, unsigned int idx) { struct can_priv *priv = netdev_priv(dev); BUG_ON(idx >= priv->echo_skb_max); /* check flag whether this packet has to be looped back */ if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK || (skb->protocol != htons(ETH_P_CAN) && skb->protocol != htons(ETH_P_CANFD))) { kfree_skb(skb); return; } if (!priv->echo_skb[idx]) { skb = can_create_echo_skb(skb); if (!skb) return; /* make settings for echo to reduce code in irq context */ skb->pkt_type = PACKET_BROADCAST; skb->ip_summed = CHECKSUM_UNNECESSARY; skb->dev = dev; /* save this skb for tx interrupt echo handling */ priv->echo_skb[idx] = skb; } else { /* locking problem with netif_stop_queue() ?? */ netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__); kfree_skb(skb); } } EXPORT_SYMBOL_GPL(can_put_echo_skb); struct sk_buff * __can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr) { struct can_priv *priv = netdev_priv(dev); if (idx >= priv->echo_skb_max) { netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n", __func__, idx, priv->echo_skb_max); return NULL; } if (priv->echo_skb[idx]) { /* Using "struct canfd_frame::len" for the frame * length is supported on both CAN and CANFD frames. */ struct sk_buff *skb = priv->echo_skb[idx]; struct canfd_frame *cf = (struct canfd_frame *)skb->data; u8 len = cf->len; *len_ptr = len; priv->echo_skb[idx] = NULL; return skb; } return NULL; } /* Get the skb from the stack and loop it back locally * * The function is typically called when the TX done interrupt * is handled in the device driver. The driver must protect * access to priv->echo_skb, if necessary. */ unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx) { struct sk_buff *skb; u8 len; skb = __can_get_echo_skb(dev, idx, &len); if (!skb) return 0; netif_rx(skb); return len; } EXPORT_SYMBOL_GPL(can_get_echo_skb); /* Remove the skb from the stack and free it. * * The function is typically called when TX failed. */ void can_free_echo_skb(struct net_device *dev, unsigned int idx) { struct can_priv *priv = netdev_priv(dev); BUG_ON(idx >= priv->echo_skb_max); if (priv->echo_skb[idx]) { dev_kfree_skb_any(priv->echo_skb[idx]); priv->echo_skb[idx] = NULL; } } EXPORT_SYMBOL_GPL(can_free_echo_skb); /* CAN device restart for bus-off recovery */ static void can_restart(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; struct sk_buff *skb; struct can_frame *cf; int err; BUG_ON(netif_carrier_ok(dev)); /* No synchronization needed because the device is bus-off and * no messages can come in or go out. */ can_flush_echo_skb(dev); /* send restart message upstream */ skb = alloc_can_err_skb(dev, &cf); if (!skb) goto restart; cf->can_id |= CAN_ERR_RESTARTED; netif_rx(skb); stats->rx_packets++; stats->rx_bytes += cf->can_dlc; restart: netdev_dbg(dev, "restarted\n"); priv->can_stats.restarts++; /* Now restart the device */ err = priv->do_set_mode(dev, CAN_MODE_START); netif_carrier_on(dev); if (err) netdev_err(dev, "Error %d during restart", err); } static void can_restart_work(struct work_struct *work) { struct delayed_work *dwork = to_delayed_work(work); struct can_priv *priv = container_of(dwork, struct can_priv, restart_work); can_restart(priv->dev); } int can_restart_now(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); /* A manual restart is only permitted if automatic restart is * disabled and the device is in the bus-off state */ if (priv->restart_ms) return -EINVAL; if (priv->state != CAN_STATE_BUS_OFF) return -EBUSY; cancel_delayed_work_sync(&priv->restart_work); can_restart(dev); return 0; } /* CAN bus-off * * This functions should be called when the device goes bus-off to * tell the netif layer that no more packets can be sent or received. * If enabled, a timer is started to trigger bus-off recovery. */ void can_bus_off(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); netdev_info(dev, "bus-off\n"); netif_carrier_off(dev); if (priv->restart_ms) schedule_delayed_work(&priv->restart_work, msecs_to_jiffies(priv->restart_ms)); } EXPORT_SYMBOL_GPL(can_bus_off); static void can_setup(struct net_device *dev) { dev->type = ARPHRD_CAN; dev->mtu = CAN_MTU; dev->hard_header_len = 0; dev->addr_len = 0; dev->tx_queue_len = 10; /* New-style flags. */ dev->flags = IFF_NOARP; dev->features = NETIF_F_HW_CSUM; } struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf) { struct sk_buff *skb; skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + sizeof(struct can_frame)); if (unlikely(!skb)) return NULL; skb->protocol = htons(ETH_P_CAN); skb->pkt_type = PACKET_BROADCAST; skb->ip_summed = CHECKSUM_UNNECESSARY; skb_reset_mac_header(skb); skb_reset_network_header(skb); skb_reset_transport_header(skb); can_skb_reserve(skb); can_skb_prv(skb)->ifindex = dev->ifindex; can_skb_prv(skb)->skbcnt = 0; *cf = skb_put_zero(skb, sizeof(struct can_frame)); return skb; } EXPORT_SYMBOL_GPL(alloc_can_skb); struct sk_buff *alloc_canfd_skb(struct net_device *dev, struct canfd_frame **cfd) { struct sk_buff *skb; skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) + sizeof(struct canfd_frame)); if (unlikely(!skb)) return NULL; skb->protocol = htons(ETH_P_CANFD); skb->pkt_type = PACKET_BROADCAST; skb->ip_summed = CHECKSUM_UNNECESSARY; skb_reset_mac_header(skb); skb_reset_network_header(skb); skb_reset_transport_header(skb); can_skb_reserve(skb); can_skb_prv(skb)->ifindex = dev->ifindex; can_skb_prv(skb)->skbcnt = 0; *cfd = skb_put_zero(skb, sizeof(struct canfd_frame)); return skb; } EXPORT_SYMBOL_GPL(alloc_canfd_skb); struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf) { struct sk_buff *skb; skb = alloc_can_skb(dev, cf); if (unlikely(!skb)) return NULL; (*cf)->can_id = CAN_ERR_FLAG; (*cf)->can_dlc = CAN_ERR_DLC; return skb; } EXPORT_SYMBOL_GPL(alloc_can_err_skb); /* Allocate and setup space for the CAN network device */ struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max, unsigned int txqs, unsigned int rxqs) { struct net_device *dev; struct can_priv *priv; int size; /* We put the driver's priv, the CAN mid layer priv and the * echo skb into the netdevice's priv. The memory layout for * the netdev_priv is like this: * * +-------------------------+ * | driver's priv | * +-------------------------+ * | struct can_ml_priv | * +-------------------------+ * | array of struct sk_buff | * +-------------------------+ */ size = ALIGN(sizeof_priv, NETDEV_ALIGN) + sizeof(struct can_ml_priv); if (echo_skb_max) size = ALIGN(size, sizeof(struct sk_buff *)) + echo_skb_max * sizeof(struct sk_buff *); dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup, txqs, rxqs); if (!dev) return NULL; priv = netdev_priv(dev); priv->dev = dev; dev->ml_priv = (void *)priv + ALIGN(sizeof_priv, NETDEV_ALIGN); if (echo_skb_max) { priv->echo_skb_max = echo_skb_max; priv->echo_skb = (void *)priv + (size - echo_skb_max * sizeof(struct sk_buff *)); } priv->state = CAN_STATE_STOPPED; INIT_DELAYED_WORK(&priv->restart_work, can_restart_work); return dev; } EXPORT_SYMBOL_GPL(alloc_candev_mqs); /* Free space of the CAN network device */ void free_candev(struct net_device *dev) { free_netdev(dev); } EXPORT_SYMBOL_GPL(free_candev); /* changing MTU and control mode for CAN/CANFD devices */ int can_change_mtu(struct net_device *dev, int new_mtu) { struct can_priv *priv = netdev_priv(dev); /* Do not allow changing the MTU while running */ if (dev->flags & IFF_UP) return -EBUSY; /* allow change of MTU according to the CANFD ability of the device */ switch (new_mtu) { case CAN_MTU: /* 'CANFD-only' controllers can not switch to CAN_MTU */ if (priv->ctrlmode_static & CAN_CTRLMODE_FD) return -EINVAL; priv->ctrlmode &= ~CAN_CTRLMODE_FD; break; case CANFD_MTU: /* check for potential CANFD ability */ if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) && !(priv->ctrlmode_static & CAN_CTRLMODE_FD)) return -EINVAL; priv->ctrlmode |= CAN_CTRLMODE_FD; break; default: return -EINVAL; } dev->mtu = new_mtu; return 0; } EXPORT_SYMBOL_GPL(can_change_mtu); /* Common open function when the device gets opened. * * This function should be called in the open function of the device * driver. */ int open_candev(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); if (!priv->bittiming.bitrate) { netdev_err(dev, "bit-timing not yet defined\n"); return -EINVAL; } /* For CAN FD the data bitrate has to be >= the arbitration bitrate */ if ((priv->ctrlmode & CAN_CTRLMODE_FD) && (!priv->data_bittiming.bitrate || priv->data_bittiming.bitrate < priv->bittiming.bitrate)) { netdev_err(dev, "incorrect/missing data bit-timing\n"); return -EINVAL; } /* Switch carrier on if device was stopped while in bus-off state */ if (!netif_carrier_ok(dev)) netif_carrier_on(dev); return 0; } EXPORT_SYMBOL_GPL(open_candev); #ifdef CONFIG_OF /* Common function that can be used to understand the limitation of * a transceiver when it provides no means to determine these limitations * at runtime. */ void of_can_transceiver(struct net_device *dev) { struct device_node *dn; struct can_priv *priv = netdev_priv(dev); struct device_node *np = dev->dev.parent->of_node; int ret; dn = of_get_child_by_name(np, "can-transceiver"); if (!dn) return; ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max); of_node_put(dn); if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max)) netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n"); } EXPORT_SYMBOL_GPL(of_can_transceiver); #endif /* Common close function for cleanup before the device gets closed. * * This function should be called in the close function of the device * driver. */ void close_candev(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); cancel_delayed_work_sync(&priv->restart_work); can_flush_echo_skb(dev); } EXPORT_SYMBOL_GPL(close_candev); /* CAN netlink interface */ static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { [IFLA_CAN_STATE] = { .type = NLA_U32 }, [IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) }, [IFLA_CAN_RESTART_MS] = { .type = NLA_U32 }, [IFLA_CAN_RESTART] = { .type = NLA_U32 }, [IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) }, [IFLA_CAN_BITTIMING_CONST] = { .len = sizeof(struct can_bittiming_const) }, [IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) }, [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) }, [IFLA_CAN_DATA_BITTIMING] = { .len = sizeof(struct can_bittiming) }, [IFLA_CAN_DATA_BITTIMING_CONST] = { .len = sizeof(struct can_bittiming_const) }, [IFLA_CAN_TERMINATION] = { .type = NLA_U16 }, }; static int can_validate(struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { bool is_can_fd = false; /* Make sure that valid CAN FD configurations always consist of * - nominal/arbitration bittiming * - data bittiming * - control mode with CAN_CTRLMODE_FD set */ if (!data) return 0; if (data[IFLA_CAN_CTRLMODE]) { struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]); is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD; } if (is_can_fd) { if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING]) return -EOPNOTSUPP; } if (data[IFLA_CAN_DATA_BITTIMING]) { if (!is_can_fd || !data[IFLA_CAN_BITTIMING]) return -EOPNOTSUPP; } return 0; } static int can_changelink(struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { struct can_priv *priv = netdev_priv(dev); int err; /* We need synchronization with dev->stop() */ ASSERT_RTNL(); if (data[IFLA_CAN_BITTIMING]) { struct can_bittiming bt; /* Do not allow changing bittiming while running */ if (dev->flags & IFF_UP) return -EBUSY; /* Calculate bittiming parameters based on * bittiming_const if set, otherwise pass bitrate * directly via do_set_bitrate(). Bail out if neither * is given. */ if (!priv->bittiming_const && !priv->do_set_bittiming) return -EOPNOTSUPP; memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt)); err = can_get_bittiming(dev, &bt, priv->bittiming_const, priv->bitrate_const, priv->bitrate_const_cnt); if (err) return err; if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) { netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n", priv->bitrate_max); return -EINVAL; } memcpy(&priv->bittiming, &bt, sizeof(bt)); if (priv->do_set_bittiming) { /* Finally, set the bit-timing registers */ err = priv->do_set_bittiming(dev); if (err) return err; } } if (data[IFLA_CAN_CTRLMODE]) { struct can_ctrlmode *cm; u32 ctrlstatic; u32 maskedflags; /* Do not allow changing controller mode while running */ if (dev->flags & IFF_UP) return -EBUSY; cm = nla_data(data[IFLA_CAN_CTRLMODE]); ctrlstatic = priv->ctrlmode_static; maskedflags = cm->flags & cm->mask; /* check whether provided bits are allowed to be passed */ if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic)) return -EOPNOTSUPP; /* do not check for static fd-non-iso if 'fd' is disabled */ if (!(maskedflags & CAN_CTRLMODE_FD)) ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO; /* make sure static options are provided by configuration */ if ((maskedflags & ctrlstatic) != ctrlstatic) return -EOPNOTSUPP; /* clear bits to be modified and copy the flag values */ priv->ctrlmode &= ~cm->mask; priv->ctrlmode |= maskedflags; /* CAN_CTRLMODE_FD can only be set when driver supports FD */ if (priv->ctrlmode & CAN_CTRLMODE_FD) dev->mtu = CANFD_MTU; else dev->mtu = CAN_MTU; } if (data[IFLA_CAN_RESTART_MS]) { /* Do not allow changing restart delay while running */ if (dev->flags & IFF_UP) return -EBUSY; priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); } if (data[IFLA_CAN_RESTART]) { /* Do not allow a restart while not running */ if (!(dev->flags & IFF_UP)) return -EINVAL; err = can_restart_now(dev); if (err) return err; } if (data[IFLA_CAN_DATA_BITTIMING]) { struct can_bittiming dbt; /* Do not allow changing bittiming while running */ if (dev->flags & IFF_UP) return -EBUSY; /* Calculate bittiming parameters based on * data_bittiming_const if set, otherwise pass bitrate * directly via do_set_bitrate(). Bail out if neither * is given. */ if (!priv->data_bittiming_const && !priv->do_set_data_bittiming) return -EOPNOTSUPP; memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]), sizeof(dbt)); err = can_get_bittiming(dev, &dbt, priv->data_bittiming_const, priv->data_bitrate_const, priv->data_bitrate_const_cnt); if (err) return err; if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) { netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n", priv->bitrate_max); return -EINVAL; } memcpy(&priv->data_bittiming, &dbt, sizeof(dbt)); if (priv->do_set_data_bittiming) { /* Finally, set the bit-timing registers */ err = priv->do_set_data_bittiming(dev); if (err) return err; } } if (data[IFLA_CAN_TERMINATION]) { const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]); const unsigned int num_term = priv->termination_const_cnt; unsigned int i; if (!priv->do_set_termination) return -EOPNOTSUPP; /* check whether given value is supported by the interface */ for (i = 0; i < num_term; i++) { if (termval == priv->termination_const[i]) break; } if (i >= num_term) return -EINVAL; /* Finally, set the termination value */ err = priv->do_set_termination(dev, termval); if (err) return err; priv->termination = termval; } return 0; } static size_t can_get_size(const struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); size_t size = 0; if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */ size += nla_total_size(sizeof(struct can_bittiming)); if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */ size += nla_total_size(sizeof(struct can_bittiming_const)); size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */ size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */ size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */ size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */ if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */ size += nla_total_size(sizeof(struct can_berr_counter)); if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */ size += nla_total_size(sizeof(struct can_bittiming)); if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */ size += nla_total_size(sizeof(struct can_bittiming_const)); if (priv->termination_const) { size += nla_total_size(sizeof(priv->termination)); /* IFLA_CAN_TERMINATION */ size += nla_total_size(sizeof(*priv->termination_const) * /* IFLA_CAN_TERMINATION_CONST */ priv->termination_const_cnt); } if (priv->bitrate_const) /* IFLA_CAN_BITRATE_CONST */ size += nla_total_size(sizeof(*priv->bitrate_const) * priv->bitrate_const_cnt); if (priv->data_bitrate_const) /* IFLA_CAN_DATA_BITRATE_CONST */ size += nla_total_size(sizeof(*priv->data_bitrate_const) * priv->data_bitrate_const_cnt); size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */ return size; } static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); struct can_ctrlmode cm = {.flags = priv->ctrlmode}; struct can_berr_counter bec; enum can_state state = priv->state; if (priv->do_get_state) priv->do_get_state(dev, &state); if ((priv->bittiming.bitrate && nla_put(skb, IFLA_CAN_BITTIMING, sizeof(priv->bittiming), &priv->bittiming)) || (priv->bittiming_const && nla_put(skb, IFLA_CAN_BITTIMING_CONST, sizeof(*priv->bittiming_const), priv->bittiming_const)) || nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) || nla_put_u32(skb, IFLA_CAN_STATE, state) || nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) || nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) || (priv->do_get_berr_counter && !priv->do_get_berr_counter(dev, &bec) && nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) || (priv->data_bittiming.bitrate && nla_put(skb, IFLA_CAN_DATA_BITTIMING, sizeof(priv->data_bittiming), &priv->data_bittiming)) || (priv->data_bittiming_const && nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST, sizeof(*priv->data_bittiming_const), priv->data_bittiming_const)) || (priv->termination_const && (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) || nla_put(skb, IFLA_CAN_TERMINATION_CONST, sizeof(*priv->termination_const) * priv->termination_const_cnt, priv->termination_const))) || (priv->bitrate_const && nla_put(skb, IFLA_CAN_BITRATE_CONST, sizeof(*priv->bitrate_const) * priv->bitrate_const_cnt, priv->bitrate_const)) || (priv->data_bitrate_const && nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST, sizeof(*priv->data_bitrate_const) * priv->data_bitrate_const_cnt, priv->data_bitrate_const)) || (nla_put(skb, IFLA_CAN_BITRATE_MAX, sizeof(priv->bitrate_max), &priv->bitrate_max)) ) return -EMSGSIZE; return 0; } static size_t can_get_xstats_size(const struct net_device *dev) { return sizeof(struct can_device_stats); } static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); if (nla_put(skb, IFLA_INFO_XSTATS, sizeof(priv->can_stats), &priv->can_stats)) goto nla_put_failure; return 0; nla_put_failure: return -EMSGSIZE; } static int can_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { return -EOPNOTSUPP; } static void can_dellink(struct net_device *dev, struct list_head *head) { } static struct rtnl_link_ops can_link_ops __read_mostly = { .kind = "can", .maxtype = IFLA_CAN_MAX, .policy = can_policy, .setup = can_setup, .validate = can_validate, .newlink = can_newlink, .changelink = can_changelink, .dellink = can_dellink, .get_size = can_get_size, .fill_info = can_fill_info, .get_xstats_size = can_get_xstats_size, .fill_xstats = can_fill_xstats, }; /* Register the CAN network device */ int register_candev(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); /* Ensure termination_const, termination_const_cnt and * do_set_termination consistency. All must be either set or * unset. */ if ((!priv->termination_const != !priv->termination_const_cnt) || (!priv->termination_const != !priv->do_set_termination)) return -EINVAL; if (!priv->bitrate_const != !priv->bitrate_const_cnt) return -EINVAL; if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt) return -EINVAL; dev->rtnl_link_ops = &can_link_ops; netif_carrier_off(dev); return register_netdev(dev); } EXPORT_SYMBOL_GPL(register_candev); /* Unregister the CAN network device */ void unregister_candev(struct net_device *dev) { unregister_netdev(dev); } EXPORT_SYMBOL_GPL(unregister_candev); /* Test if a network device is a candev based device * and return the can_priv* if so. */ struct can_priv *safe_candev_priv(struct net_device *dev) { if (dev->type != ARPHRD_CAN || dev->rtnl_link_ops != &can_link_ops) return NULL; return netdev_priv(dev); } EXPORT_SYMBOL_GPL(safe_candev_priv); static __init int can_dev_init(void) { int err; can_led_notifier_init(); err = rtnl_link_register(&can_link_ops); if (!err) pr_info(MOD_DESC "\n"); return err; } module_init(can_dev_init); static __exit void can_dev_exit(void) { rtnl_link_unregister(&can_link_ops); can_led_notifier_exit(); } module_exit(can_dev_exit); MODULE_ALIAS_RTNL_LINK("can");