diff options
Diffstat (limited to 'drivers/net/can/dev.c')
| -rw-r--r-- | drivers/net/can/dev.c | 1324 |
1 files changed, 1324 insertions, 0 deletions
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c new file mode 100644 index 000000000..8738d37f7 --- /dev/null +++ b/drivers/net/can/dev.c @@ -0,0 +1,1324 @@ +/* + * Copyright (C) 2005 Marc Kleine-Budde, Pengutronix + * Copyright (C) 2006 Andrey Volkov, Varma Electronics + * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the version 2 of the GNU General Public License + * as published by the Free Software Foundation + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/netdevice.h> +#include <linux/if_arp.h> +#include <linux/workqueue.h> +#include <linux/can.h> +#include <linux/can/dev.h> +#include <linux/can/skb.h> +#include <linux/can/netlink.h> +#include <linux/can/led.h> +#include <linux/of.h> +#include <net/rtnetlink.h> + +#define MOD_DESC "CAN device driver interface" + +MODULE_DESCRIPTION(MOD_DESC); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); + +/* 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; + + /* get the real payload length for netdev statistics */ + if (cf->can_id & CAN_RTR_FLAG) + *len_ptr = 0; + else + *len_ptr = cf->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; + + skb_get(skb); + if (netif_rx(skb) == NET_RX_SUCCESS) + dev_consume_skb_any(skb); + else + dev_kfree_skb_any(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 == NULL) { + err = -ENOMEM; + goto restart; + } + cf->can_id |= CAN_ERR_RESTARTED; + + stats->rx_packets++; + stats->rx_bytes += cf->can_dlc; + + netif_rx_ni(skb); + +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; + + if (echo_skb_max) + size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) + + echo_skb_max * sizeof(struct sk_buff *); + else + size = sizeof_priv; + + 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; + + if (echo_skb_max) { + priv->echo_skb_max = echo_skb_max; + priv->echo_skb = (void *)priv + + ALIGN(sizeof_priv, 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) +{ + return; +} + +static struct rtnl_link_ops can_link_ops __read_mostly = { + .kind = "can", + .netns_refund = true, + .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) + printk(KERN_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"); |