From 585a4f22c4f9d85e32d42be65e67c232e82e5b3a Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Wed, 26 Nov 2025 11:16:03 +0100 Subject: can: bittiming: apply NL_SET_ERR_MSG() to can_calc_bittiming() When CONFIG_CAN_CALC_BITTIMING is disabled, the can_calc_bittiming() functions can not be used and the user needs to provide all the bittiming parameters. Currently, can_calc_bittiming() prints an error message to the kernel log. Instead use NL_SET_ERR_MSG() to make it return the error message through the netlink interface so that the user can directly see it. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-2-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde --- include/linux/can/bittiming.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h index d30816dd93c7..3926c78b2222 100644 --- a/include/linux/can/bittiming.h +++ b/include/linux/can/bittiming.h @@ -141,7 +141,7 @@ static inline int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt, const struct can_bittiming_const *btc, struct netlink_ext_ack *extack) { - netdev_err(dev, "bit-timing calculation not available\n"); + NL_SET_ERR_MSG(extack, "bit-timing calculation not available\n"); return -EINVAL; } -- cgit From d037d05c2e32792a6fa572b0aa3c92a8ac78589d Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Wed, 26 Nov 2025 11:16:04 +0100 Subject: can: dev: can_dev_dropped_skb: drop CAN FD skbs if FD is off Currently, the CAN FD skb validation logic is based on the MTU: the interface is deemed FD capable if and only if its MTU is greater or equal to CANFD_MTU. This logic is showing its limit with the introduction of CAN XL. For example, consider the two scenarios below: 1. An interface configured with CAN FD on and CAN XL on 2. An interface configured with CAN FD off and CAN XL on In those two scenarios, the interfaces would have the same MTU: CANXL_MTU making it impossible to differentiate which one has CAN FD turned on and which one has it off. Because of the limitation, the only non-UAPI-breaking workaround is to do the check at the device level using the can_priv->ctrlmode flags. Unfortunately, the virtual interfaces (vcan, vxcan), which do not have a can_priv, are left behind. Add a check on the CAN_CTRLMODE_FD flag in can_dev_dropped_skb() and drop FD frames whenever the feature is turned off. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-3-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde --- include/linux/can/dev.h | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index bd7410b5d8a6..a7a39a6101d9 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -103,12 +103,20 @@ static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *s if (priv->ctrlmode & CAN_CTRLMODE_LISTENONLY) { netdev_info_once(dev, "interface in listen only mode, dropping skb\n"); - kfree_skb(skb); - dev->stats.tx_dropped++; - return true; + goto invalid_skb; + } + + if (!(priv->ctrlmode & CAN_CTRLMODE_FD) && can_is_canfd_skb(skb)) { + netdev_info_once(dev, "CAN FD is disabled, dropping skb\n"); + goto invalid_skb; } return can_dropped_invalid_skb(dev, skb); + +invalid_skb: + kfree_skb(skb); + dev->stats.tx_dropped++; + return true; } void can_setup(struct net_device *dev); -- cgit From 60f511f443e552ef5b5cd79ec2b881f4323e19c9 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Wed, 26 Nov 2025 11:16:05 +0100 Subject: can: netlink: add CAN_CTRLMODE_RESTRICTED ISO 11898-1:2024 adds a new restricted operation mode. This mode is added as a mandatory feature for nodes which support CAN XL and is retrofitted as optional for legacy nodes (i.e. the ones which only support Classical CAN and CAN FD). The restricted operation mode is nearly the same as the listen only mode: the node can not send data frames or remote frames and can not send dominant bits if an error occurs. The only exception is that the node shall still send the acknowledgment bit. A second niche exception is that the node may still send a data frame containing a time reference message if the node is a primary time provider, but because the time provider feature is not yet implemented in the kernel, this second exception is not relevant to us at the moment. Add the CAN_CTRLMODE_RESTRICTED control mode flag and update the can_dev_dropped_skb() helper function accordingly. Finally, bail out if both CAN_CTRLMODE_LISTENONLY and CAN_CTRLMODE_RESTRICTED are provided. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-4-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/dev.c | 2 ++ drivers/net/can/dev/netlink.c | 7 ++++++ include/linux/can/dev.h | 50 +++++++++++++++++++++------------------- include/uapi/linux/can/netlink.h | 1 + 4 files changed, 36 insertions(+), 24 deletions(-) (limited to 'include') diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c index b392483e4499..b6980d32e5b4 100644 --- a/drivers/net/can/dev/dev.c +++ b/drivers/net/can/dev/dev.c @@ -115,6 +115,8 @@ const char *can_get_ctrlmode_str(u32 ctrlmode) return "TDC-AUTO"; case CAN_CTRLMODE_TDC_MANUAL: return "TDC-MANUAL"; + case CAN_CTRLMODE_RESTRICTED: + return "RESTRICTED"; default: return ""; } diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index 6f83b87d54fc..87e731527dd7 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -188,6 +188,13 @@ static int can_validate(struct nlattr *tb[], struct nlattr *data[], struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]); flags = cm->flags & cm->mask; + + if ((flags & CAN_CTRLMODE_LISTENONLY) && + (flags & CAN_CTRLMODE_RESTRICTED)) { + NL_SET_ERR_MSG(extack, + "LISTEN-ONLY and RESTRICTED modes are mutually exclusive"); + return -EOPNOTSUPP; + } } err = can_validate_bittiming(data, extack, IFLA_CAN_BITTIMING); diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index a7a39a6101d9..ab11c0e9111b 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -95,30 +95,6 @@ static inline bool can_is_canxl_dev_mtu(unsigned int mtu) return (mtu >= CANXL_MIN_MTU && mtu <= CANXL_MAX_MTU); } -/* drop skb if it does not contain a valid CAN frame for sending */ -static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *skb) -{ - struct can_priv *priv = netdev_priv(dev); - - if (priv->ctrlmode & CAN_CTRLMODE_LISTENONLY) { - netdev_info_once(dev, - "interface in listen only mode, dropping skb\n"); - goto invalid_skb; - } - - if (!(priv->ctrlmode & CAN_CTRLMODE_FD) && can_is_canfd_skb(skb)) { - netdev_info_once(dev, "CAN FD is disabled, dropping skb\n"); - goto invalid_skb; - } - - return can_dropped_invalid_skb(dev, skb); - -invalid_skb: - kfree_skb(skb); - dev->stats.tx_dropped++; - return true; -} - void can_setup(struct net_device *dev); struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max, @@ -154,6 +130,32 @@ void can_bus_off(struct net_device *dev); const char *can_get_state_str(const enum can_state state); const char *can_get_ctrlmode_str(u32 ctrlmode); +/* drop skb if it does not contain a valid CAN frame for sending */ +static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *skb) +{ + struct can_priv *priv = netdev_priv(dev); + u32 silent_mode = priv->ctrlmode & (CAN_CTRLMODE_LISTENONLY | + CAN_CTRLMODE_RESTRICTED); + + if (silent_mode) { + netdev_info_once(dev, "interface in %s mode, dropping skb\n", + can_get_ctrlmode_str(silent_mode)); + goto invalid_skb; + } + + if (!(priv->ctrlmode & CAN_CTRLMODE_FD) && can_is_canfd_skb(skb)) { + netdev_info_once(dev, "CAN FD is disabled, dropping skb\n"); + goto invalid_skb; + } + + return can_dropped_invalid_skb(dev, skb); + +invalid_skb: + kfree_skb(skb); + dev->stats.tx_dropped++; + return true; +} + void can_state_get_by_berr_counter(const struct net_device *dev, const struct can_berr_counter *bec, enum can_state *tx_state, diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h index ef62f56eaaef..fafd1cce4798 100644 --- a/include/uapi/linux/can/netlink.h +++ b/include/uapi/linux/can/netlink.h @@ -103,6 +103,7 @@ struct can_ctrlmode { #define CAN_CTRLMODE_CC_LEN8_DLC 0x100 /* Classic CAN DLC option */ #define CAN_CTRLMODE_TDC_AUTO 0x200 /* FD transceiver automatically calculates TDCV */ #define CAN_CTRLMODE_TDC_MANUAL 0x400 /* FD TDCV is manually set up by user */ +#define CAN_CTRLMODE_RESTRICTED 0x800 /* Restricted operation mode */ /* * CAN device statistics -- cgit From e63281614747c73f25b708c75bc696c4e76f5588 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Wed, 26 Nov 2025 11:16:06 +0100 Subject: can: netlink: add initial CAN XL support CAN XL uses bittiming parameters different from Classical CAN and CAN FD. Thus, all the data bittiming parameters, including TDC, need to be duplicated for CAN XL. Add the CAN XL netlink interface for all the features which are common with CAN FD. Any new CAN XL specific features are added later on. The first time CAN XL is activated, the MTU is set by default to CANXL_MAX_MTU. The user may then configure a custom MTU within the CANXL_MIN_MTU to CANXL_MAX_MTU range, in which case, the custom MTU value will be kept as long as CAN XL remains active. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-5-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/dev.c | 14 +++++++- drivers/net/can/dev/netlink.c | 76 +++++++++++++++++++++++++++++++--------- include/linux/can/bittiming.h | 6 ++-- include/linux/can/dev.h | 7 +++- include/uapi/linux/can/netlink.h | 7 ++++ 5 files changed, 90 insertions(+), 20 deletions(-) (limited to 'include') diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c index b6980d32e5b4..bdec2c52c8ec 100644 --- a/drivers/net/can/dev/dev.c +++ b/drivers/net/can/dev/dev.c @@ -117,6 +117,12 @@ const char *can_get_ctrlmode_str(u32 ctrlmode) return "TDC-MANUAL"; case CAN_CTRLMODE_RESTRICTED: return "RESTRICTED"; + case CAN_CTRLMODE_XL: + return "XL"; + case CAN_CTRLMODE_XL_TDC_AUTO: + return "XL-TDC-AUTO"; + case CAN_CTRLMODE_XL_TDC_MANUAL: + return "XL-TDC-MANUAL"; default: return ""; } @@ -350,7 +356,13 @@ void can_set_default_mtu(struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); - if (priv->ctrlmode & CAN_CTRLMODE_FD) { + if (priv->ctrlmode & CAN_CTRLMODE_XL) { + if (can_is_canxl_dev_mtu(dev->mtu)) + return; + dev->mtu = CANXL_MTU; + dev->min_mtu = CANXL_MIN_MTU; + dev->max_mtu = CANXL_MAX_MTU; + } else if (priv->ctrlmode & CAN_CTRLMODE_FD) { dev->mtu = CANFD_MTU; dev->min_mtu = CANFD_MTU; dev->max_mtu = CANFD_MTU; diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index 87e731527dd7..fdd1fa7cf93a 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -2,7 +2,7 @@ /* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix * Copyright (C) 2006 Andrey Volkov, Varma Electronics * Copyright (C) 2008-2009 Wolfgang Grandegger - * Copyright (C) 2021 Vincent Mailhol + * Copyright (C) 2021-2025 Vincent Mailhol */ #include @@ -22,6 +22,9 @@ static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { [IFLA_CAN_TERMINATION] = { .type = NLA_U16 }, [IFLA_CAN_TDC] = { .type = NLA_NESTED }, [IFLA_CAN_CTRLMODE_EXT] = { .type = NLA_NESTED }, + [IFLA_CAN_XL_DATA_BITTIMING] = { .len = sizeof(struct can_bittiming) }, + [IFLA_CAN_XL_DATA_BITTIMING_CONST] = { .len = sizeof(struct can_bittiming_const) }, + [IFLA_CAN_XL_TDC] = { .type = NLA_NESTED }, }; static const struct nla_policy can_tdc_policy[IFLA_CAN_TDC_MAX + 1] = { @@ -70,7 +73,7 @@ static int can_validate_tdc(struct nlattr *data_tdc, return -EOPNOTSUPP; } - /* If one of the CAN_CTRLMODE_TDC_* flag is set then TDC + /* If one of the CAN_CTRLMODE_{,XL}_TDC_* flags is set then TDC * must be set and vice-versa */ if ((tdc_auto || tdc_manual) && !data_tdc) { @@ -82,8 +85,8 @@ static int can_validate_tdc(struct nlattr *data_tdc, return -EOPNOTSUPP; } - /* If providing TDC parameters, at least TDCO is needed. TDCV - * is needed if and only if CAN_CTRLMODE_TDC_MANUAL is set + /* If providing TDC parameters, at least TDCO is needed. TDCV is + * needed if and only if CAN_CTRLMODE_{,XL}_TDC_MANUAL is set */ if (data_tdc) { struct nlattr *tb_tdc[IFLA_CAN_TDC_MAX + 1]; @@ -126,10 +129,10 @@ static int can_validate_databittiming(struct nlattr *data[], bool is_on; int err; - /* Make sure that valid CAN FD configurations always consist of + /* Make sure that valid CAN FD/XL configurations always consist of * - nominal/arbitration bittiming * - data bittiming - * - control mode with CAN_CTRLMODE_FD set + * - control mode with CAN_CTRLMODE_{FD,XL} set * - TDC parameters are coherent (details in can_validate_tdc()) */ @@ -139,7 +142,10 @@ static int can_validate_databittiming(struct nlattr *data[], is_on = flags & CAN_CTRLMODE_FD; type = "FD"; } else { - return -EOPNOTSUPP; /* Place holder for CAN XL */ + data_tdc = data[IFLA_CAN_XL_TDC]; + tdc_flags = flags & CAN_CTRLMODE_XL_TDC_MASK; + is_on = flags & CAN_CTRLMODE_XL; + type = "XL"; } if (is_on) { @@ -206,6 +212,11 @@ static int can_validate(struct nlattr *tb[], struct nlattr *data[], if (err) return err; + err = can_validate_databittiming(data, extack, + IFLA_CAN_XL_DATA_BITTIMING, flags); + if (err) + return err; + return 0; } @@ -251,18 +262,26 @@ static int can_ctrlmode_changelink(struct net_device *dev, /* If a top dependency flag is provided, reset all its dependencies */ if (cm->mask & CAN_CTRLMODE_FD) priv->ctrlmode &= ~CAN_CTRLMODE_FD_TDC_MASK; + if (cm->mask & CAN_CTRLMODE_XL) + priv->ctrlmode &= ~(CAN_CTRLMODE_XL_TDC_MASK); /* clear bits to be modified and copy the flag values */ priv->ctrlmode &= ~cm->mask; priv->ctrlmode |= maskedflags; - /* Wipe potential leftovers from previous CAN FD config */ + /* Wipe potential leftovers from previous CAN FD/XL config */ if (!(priv->ctrlmode & CAN_CTRLMODE_FD)) { memset(&priv->fd.data_bittiming, 0, sizeof(priv->fd.data_bittiming)); priv->ctrlmode &= ~CAN_CTRLMODE_FD_TDC_MASK; memset(&priv->fd.tdc, 0, sizeof(priv->fd.tdc)); } + if (!(priv->ctrlmode & CAN_CTRLMODE_XL)) { + memset(&priv->xl.data_bittiming, 0, + sizeof(priv->fd.data_bittiming)); + priv->ctrlmode &= ~CAN_CTRLMODE_XL_TDC_MASK; + memset(&priv->xl.tdc, 0, sizeof(priv->xl.tdc)); + } can_set_default_mtu(dev); @@ -337,7 +356,10 @@ static int can_dbt_changelink(struct net_device *dev, struct nlattr *data[], dbt_params = &priv->fd; tdc_mask = CAN_CTRLMODE_FD_TDC_MASK; } else { - return -EOPNOTSUPP; /* Place holder for CAN XL */ + data_bittiming = data[IFLA_CAN_XL_DATA_BITTIMING]; + data_tdc = data[IFLA_CAN_XL_TDC]; + dbt_params = &priv->xl; + tdc_mask = CAN_CTRLMODE_XL_TDC_MASK; } if (!data_bittiming) @@ -388,7 +410,7 @@ static int can_dbt_changelink(struct net_device *dev, struct nlattr *data[], */ can_calc_tdco(&dbt_params->tdc, dbt_params->tdc_const, &dbt, tdc_mask, &priv->ctrlmode, priv->ctrlmode_supported); - } /* else: both CAN_CTRLMODE_TDC_{AUTO,MANUAL} are explicitly + } /* else: both CAN_CTRLMODE_{,XL}_TDC_{AUTO,MANUAL} are explicitly * turned off. TDC is disabled: do nothing */ @@ -493,6 +515,11 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[], if (err) return err; + /* CAN XL */ + err = can_dbt_changelink(dev, data, false, extack); + 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; @@ -560,14 +587,14 @@ static size_t can_data_bittiming_get_size(struct data_bittiming_params *dbt_para { size_t size = 0; - if (dbt_params->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */ + if (dbt_params->data_bittiming.bitrate) /* IFLA_CAN_{,XL}_DATA_BITTIMING */ size += nla_total_size(sizeof(dbt_params->data_bittiming)); - if (dbt_params->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */ + if (dbt_params->data_bittiming_const) /* IFLA_CAN_{,XL}_DATA_BITTIMING_CONST */ size += nla_total_size(sizeof(*dbt_params->data_bittiming_const)); - if (dbt_params->data_bitrate_const) /* IFLA_CAN_DATA_BITRATE_CONST */ + if (dbt_params->data_bitrate_const) /* IFLA_CAN_{,XL}_DATA_BITRATE_CONST */ size += nla_total_size(sizeof(*dbt_params->data_bitrate_const) * dbt_params->data_bitrate_const_cnt); - size += can_tdc_get_size(dbt_params, tdc_flags);/* IFLA_CAN_TDC */ + size += can_tdc_get_size(dbt_params, tdc_flags);/* IFLA_CAN_{,XL}_TDC */ return size; } @@ -607,6 +634,9 @@ static size_t can_get_size(const struct net_device *dev) size += can_data_bittiming_get_size(&priv->fd, priv->ctrlmode & CAN_CTRLMODE_FD_TDC_MASK); + size += can_data_bittiming_get_size(&priv->xl, + priv->ctrlmode & CAN_CTRLMODE_XL_TDC_MASK); + return size; } @@ -651,7 +681,9 @@ static int can_tdc_fill_info(struct sk_buff *skb, const struct net_device *dev, tdc_is_enabled = can_fd_tdc_is_enabled(priv); tdc_manual = priv->ctrlmode & CAN_CTRLMODE_TDC_MANUAL; } else { - return -EOPNOTSUPP; /* Place holder for CAN XL */ + dbt_params = &priv->xl; + tdc_is_enabled = can_xl_tdc_is_enabled(priv); + tdc_manual = priv->ctrlmode & CAN_CTRLMODE_XL_TDC_MANUAL; } tdc_const = dbt_params->tdc_const; tdc = &dbt_params->tdc; @@ -773,7 +805,19 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) can_tdc_fill_info(skb, dev, IFLA_CAN_TDC) || - can_ctrlmode_ext_fill_info(skb, priv) + can_ctrlmode_ext_fill_info(skb, priv) || + + can_bittiming_fill_info(skb, IFLA_CAN_XL_DATA_BITTIMING, + &priv->xl.data_bittiming) || + + can_bittiming_const_fill_info(skb, IFLA_CAN_XL_DATA_BITTIMING_CONST, + priv->xl.data_bittiming_const) || + + can_bitrate_const_fill_info(skb, IFLA_CAN_XL_DATA_BITRATE_CONST, + priv->xl.data_bitrate_const, + priv->xl.data_bitrate_const_cnt) || + + can_tdc_fill_info(skb, dev, IFLA_CAN_XL_TDC) ) return -EMSGSIZE; diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h index 3926c78b2222..b6cd2476ffd7 100644 --- a/include/linux/can/bittiming.h +++ b/include/linux/can/bittiming.h @@ -16,10 +16,12 @@ #define CAN_CTRLMODE_FD_TDC_MASK \ (CAN_CTRLMODE_TDC_AUTO | CAN_CTRLMODE_TDC_MANUAL) +#define CAN_CTRLMODE_XL_TDC_MASK \ + (CAN_CTRLMODE_XL_TDC_AUTO | CAN_CTRLMODE_XL_TDC_MANUAL) #define CAN_CTRLMODE_TDC_AUTO_MASK \ - (CAN_CTRLMODE_TDC_AUTO) + (CAN_CTRLMODE_TDC_AUTO | CAN_CTRLMODE_XL_TDC_AUTO) #define CAN_CTRLMODE_TDC_MANUAL_MASK \ - (CAN_CTRLMODE_TDC_MANUAL) + (CAN_CTRLMODE_TDC_MANUAL | CAN_CTRLMODE_XL_TDC_MANUAL) /* * struct can_tdc - CAN FD Transmission Delay Compensation parameters diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index ab11c0e9111b..f15879bd818d 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -47,7 +47,7 @@ struct can_priv { const struct can_bittiming_const *bittiming_const; struct can_bittiming bittiming; - struct data_bittiming_params fd; + struct data_bittiming_params fd, xl; unsigned int bitrate_const_cnt; const u32 *bitrate_const; u32 bitrate_max; @@ -85,6 +85,11 @@ static inline bool can_fd_tdc_is_enabled(const struct can_priv *priv) return !!(priv->ctrlmode & CAN_CTRLMODE_FD_TDC_MASK); } +static inline bool can_xl_tdc_is_enabled(const struct can_priv *priv) +{ + return !!(priv->ctrlmode & CAN_CTRLMODE_XL_TDC_MASK); +} + static inline u32 can_get_static_ctrlmode(struct can_priv *priv) { return priv->ctrlmode & ~priv->ctrlmode_supported; diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h index fafd1cce4798..c2c96c5978a8 100644 --- a/include/uapi/linux/can/netlink.h +++ b/include/uapi/linux/can/netlink.h @@ -104,6 +104,9 @@ struct can_ctrlmode { #define CAN_CTRLMODE_TDC_AUTO 0x200 /* FD transceiver automatically calculates TDCV */ #define CAN_CTRLMODE_TDC_MANUAL 0x400 /* FD TDCV is manually set up by user */ #define CAN_CTRLMODE_RESTRICTED 0x800 /* Restricted operation mode */ +#define CAN_CTRLMODE_XL 0x1000 /* CAN XL mode */ +#define CAN_CTRLMODE_XL_TDC_AUTO 0x2000 /* XL transceiver automatically calculates TDCV */ +#define CAN_CTRLMODE_XL_TDC_MANUAL 0x4000 /* XL TDCV is manually set up by user */ /* * CAN device statistics @@ -139,6 +142,10 @@ enum { IFLA_CAN_BITRATE_MAX, IFLA_CAN_TDC, /* FD */ IFLA_CAN_CTRLMODE_EXT, + IFLA_CAN_XL_DATA_BITTIMING, + IFLA_CAN_XL_DATA_BITTIMING_CONST, + IFLA_CAN_XL_DATA_BITRATE_CONST, + IFLA_CAN_XL_TDC, /* add new constants above here */ __IFLA_CAN_MAX, -- cgit From 233134af208689c2d5d40896f5740473a74e3cb2 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Wed, 26 Nov 2025 11:16:07 +0100 Subject: can: netlink: add CAN_CTRLMODE_XL_TMS flag The Transceiver Mode Switching (TMS) indicates whether the CAN XL controller shall use the PWM or NRZ encoding during the data phase. The term "transceiver mode switching" is used in both ISO 11898-1 and CiA 612-2 (although only the latter one uses the abbreviation TMS). We adopt the same naming convention here for consistency. Add the CAN_CTRLMODE_XL_TMS flag to the list of the CAN control modes. Add can_validate_xl_flags() to check the coherency of the TMS flag. That function will be reused in upcoming changes to validate the other CAN XL flags. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-6-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/dev.c | 2 ++ drivers/net/can/dev/netlink.c | 48 +++++++++++++++++++++++++++++++++++++--- include/uapi/linux/can/netlink.h | 1 + 3 files changed, 48 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c index bdec2c52c8ec..091f30e94c61 100644 --- a/drivers/net/can/dev/dev.c +++ b/drivers/net/can/dev/dev.c @@ -123,6 +123,8 @@ const char *can_get_ctrlmode_str(u32 ctrlmode) return "XL-TDC-AUTO"; case CAN_CTRLMODE_XL_TDC_MANUAL: return "XL-TDC-MANUAL"; + case CAN_CTRLMODE_XL_TMS: + return "TMS"; default: return ""; } diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index fdd1fa7cf93a..b2c24439abba 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -181,6 +181,32 @@ static int can_validate_databittiming(struct nlattr *data[], return 0; } +static int can_validate_xl_flags(struct netlink_ext_ack *extack, + u32 masked_flags, u32 mask) +{ + if (masked_flags & CAN_CTRLMODE_XL) { + if (masked_flags & CAN_CTRLMODE_XL_TMS) { + const u32 tms_conflicts_mask = CAN_CTRLMODE_FD | + CAN_CTRLMODE_XL_TDC_MASK; + u32 tms_conflicts = masked_flags & tms_conflicts_mask; + + if (tms_conflicts) { + NL_SET_ERR_MSG_FMT(extack, + "TMS and %s are mutually exclusive", + can_get_ctrlmode_str(tms_conflicts)); + return -EOPNOTSUPP; + } + } + } else { + if (mask & CAN_CTRLMODE_XL_TMS) { + NL_SET_ERR_MSG(extack, "TMS requires CAN XL"); + return -EOPNOTSUPP; + } + } + + return 0; +} + static int can_validate(struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { @@ -201,6 +227,10 @@ static int can_validate(struct nlattr *tb[], struct nlattr *data[], "LISTEN-ONLY and RESTRICTED modes are mutually exclusive"); return -EOPNOTSUPP; } + + err = can_validate_xl_flags(extack, flags, cm->mask); + if (err) + return err; } err = can_validate_bittiming(data, extack, IFLA_CAN_BITTIMING); @@ -226,7 +256,7 @@ static int can_ctrlmode_changelink(struct net_device *dev, { struct can_priv *priv = netdev_priv(dev); struct can_ctrlmode *cm; - u32 ctrlstatic, maskedflags, notsupp, ctrlstatic_missing; + u32 ctrlstatic, maskedflags, deactivated, notsupp, ctrlstatic_missing; if (!data[IFLA_CAN_CTRLMODE]) return 0; @@ -238,6 +268,7 @@ static int can_ctrlmode_changelink(struct net_device *dev, cm = nla_data(data[IFLA_CAN_CTRLMODE]); ctrlstatic = can_get_static_ctrlmode(priv); maskedflags = cm->flags & cm->mask; + deactivated = ~cm->flags & cm->mask; notsupp = maskedflags & ~(priv->ctrlmode_supported | ctrlstatic); ctrlstatic_missing = (maskedflags & ctrlstatic) ^ ctrlstatic; @@ -259,11 +290,21 @@ static int can_ctrlmode_changelink(struct net_device *dev, return -EOPNOTSUPP; } + /* If FD was active and is not turned off, check for XL conflicts */ + if (priv->ctrlmode & CAN_CTRLMODE_FD & ~deactivated) { + if (maskedflags & CAN_CTRLMODE_XL_TMS) { + NL_SET_ERR_MSG(extack, + "TMS can not be activated while CAN FD is on"); + return -EOPNOTSUPP; + } + } + /* If a top dependency flag is provided, reset all its dependencies */ if (cm->mask & CAN_CTRLMODE_FD) priv->ctrlmode &= ~CAN_CTRLMODE_FD_TDC_MASK; if (cm->mask & CAN_CTRLMODE_XL) - priv->ctrlmode &= ~(CAN_CTRLMODE_XL_TDC_MASK); + priv->ctrlmode &= ~(CAN_CTRLMODE_XL_TDC_MASK | + CAN_CTRLMODE_XL_TMS); /* clear bits to be modified and copy the flag values */ priv->ctrlmode &= ~cm->mask; @@ -395,7 +436,8 @@ static int can_dbt_changelink(struct net_device *dev, struct nlattr *data[], if (data[IFLA_CAN_CTRLMODE]) { struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]); - need_tdc_calc = !(cm->mask & tdc_mask); + if (fd || !(priv->ctrlmode & CAN_CTRLMODE_XL_TMS)) + need_tdc_calc = !(cm->mask & tdc_mask); } if (data_tdc) { /* TDC parameters are provided: use them */ diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h index c2c96c5978a8..ebafb091d80f 100644 --- a/include/uapi/linux/can/netlink.h +++ b/include/uapi/linux/can/netlink.h @@ -107,6 +107,7 @@ struct can_ctrlmode { #define CAN_CTRLMODE_XL 0x1000 /* CAN XL mode */ #define CAN_CTRLMODE_XL_TDC_AUTO 0x2000 /* XL transceiver automatically calculates TDCV */ #define CAN_CTRLMODE_XL_TDC_MANUAL 0x4000 /* XL TDCV is manually set up by user */ +#define CAN_CTRLMODE_XL_TMS 0x8000 /* Transceiver Mode Switching */ /* * CAN device statistics -- cgit From 6df01533e535d21cac779ff35cc25c43304035c3 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Wed, 26 Nov 2025 11:16:08 +0100 Subject: can: dev: can_dev_dropped_skb: drop CC/FD frames in CANXL-only mode The error-signalling (ES) is a mandatory functionality for CAN CC and CAN FD to report CAN frame format violations by sending an error-frame signal on the bus. A so-called 'mixed-mode' is intended to have (XL-tolerant) CAN FD nodes and CAN XL nodes on one CAN segment, where the FD-controllers can talk CC/FD and the XL-controllers can talk CC/FD/XL. This mixed-mode utilizes the error-signalling for sending CC/FD/XL frames. The CANXL-only mode disables the error-signalling in the CAN XL controller. This mode does not allow CC/FD frames to be sent but additionally offers a CAN XL transceiver mode switching (TMS). Configured with CAN_CTRLMODE_FD and CAN_CTRLMODE_XL this leads to: FD=0 XL=0 CC-only mode (ES=1) FD=1 XL=0 FD/CC mixed-mode (ES=1) FD=1 XL=1 XL/FD/CC mixed-mode (ES=1) FD=0 XL=1 XL-only mode (ES=0, TMS optional) The helper function can_dev_in_xl_only_mode() determines the required value to disable error signalling in the CAN XL controller. Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-7-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde --- include/linux/can/dev.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'include') diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index f15879bd818d..52c8be5c160e 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -135,6 +135,19 @@ void can_bus_off(struct net_device *dev); const char *can_get_state_str(const enum can_state state); const char *can_get_ctrlmode_str(u32 ctrlmode); +static inline bool can_dev_in_xl_only_mode(struct can_priv *priv) +{ + const u32 mixed_mode = CAN_CTRLMODE_FD | CAN_CTRLMODE_XL; + + /* When CAN XL is enabled but FD is disabled we are running in + * the so-called 'CANXL-only mode' where the error signalling is + * disabled. This helper function determines the required value + * to disable error signalling in the CAN XL controller. + * The so-called CC/FD/XL 'mixed mode' requires error signalling. + */ + return ((priv->ctrlmode & mixed_mode) == CAN_CTRLMODE_XL); +} + /* drop skb if it does not contain a valid CAN frame for sending */ static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *skb) { @@ -153,6 +166,12 @@ static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *s goto invalid_skb; } + if (can_dev_in_xl_only_mode(priv) && !can_is_canxl_skb(skb)) { + netdev_info_once(dev, + "Error signaling is disabled, dropping skb\n"); + goto invalid_skb; + } + return can_dropped_invalid_skb(dev, skb); invalid_skb: -- cgit From f6ccc2b293ba27e9171c63e456d9cba664fa2337 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Wed, 26 Nov 2025 11:16:09 +0100 Subject: can: bittiming: add PWM parameters In CAN XL, higher data bit rates require the CAN transceiver to switch its operation mode to use Pulse-Width Modulation (PWM) transmission mode instead of the classic dominant/recessive transmission mode. The PWM parameters are: - PWMS: pulse width modulation short phase - PWML: pulse width modulation long phase - PWMO: pulse width modulation offset CiA 612-2 specifies PWMS and PWML to be at least 1 (arguably, PWML shall be at least 2 to respect the PWMS < PWML rule). PWMO's minimum is expected to always be zero. It is added more for consistency than anything else. Add struct can_pwm_const so that the different devices can provide their minimum and maximum values. When TMS is on, the runtime PWMS, PWML and PWMO are needed (either calculated or provided by the user): add struct can_pwm to store these. TDC and PWM can not be used at the same time (TDC can only be used when TMS is off and PWM only when TMS is on). struct can_pwm is thus put together with struct can_tdc inside a union to save some space. The netlink logic will be added in an upcoming change. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-8-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde --- include/linux/can/bittiming.h | 41 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 39 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h index b6cd2476ffd7..967d76689c4f 100644 --- a/include/linux/can/bittiming.h +++ b/include/linux/can/bittiming.h @@ -1,6 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0-only */ /* Copyright (c) 2020 Pengutronix, Marc Kleine-Budde - * Copyright (c) 2021 Vincent Mailhol + * Copyright (c) 2021-2025 Vincent Mailhol */ #ifndef _CAN_BITTIMING_H @@ -120,11 +120,48 @@ struct can_tdc_const { u32 tdcf_max; }; +/* + * struct can_pwm - CAN Pulse-Width Modulation (PWM) parameters + * + * @pwms: pulse width modulation short phase + * @pwml: pulse width modulation long phase + * @pwmo: pulse width modulation offset + */ +struct can_pwm { + u32 pwms; + u32 pwml; + u32 pwmo; +}; + +/* + * struct can_pwm - CAN hardware-dependent constants for Pulse-Width + * Modulation (PWM) + * + * @pwms_min: PWM short phase minimum value. Must be at least 1. + * @pwms_max: PWM short phase maximum value + * @pwml_min: PWM long phase minimum value. Must be at least 1. + * @pwml_max: PWM long phase maximum value + * @pwmo_min: PWM offset phase minimum value + * @pwmo_max: PWM offset phase maximum value + */ +struct can_pwm_const { + u32 pwms_min; + u32 pwms_max; + u32 pwml_min; + u32 pwml_max; + u32 pwmo_min; + u32 pwmo_max; +}; + struct data_bittiming_params { const struct can_bittiming_const *data_bittiming_const; struct can_bittiming data_bittiming; const struct can_tdc_const *tdc_const; - struct can_tdc tdc; + const struct can_pwm_const *pwm_const; + union { + struct can_tdc tdc; + struct can_pwm pwm; + }; const u32 *data_bitrate_const; unsigned int data_bitrate_const_cnt; int (*do_set_data_bittiming)(struct net_device *dev); -- cgit From 8e2a2885a2a6217190065d1aae98fe88a670cc28 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Wed, 26 Nov 2025 11:16:10 +0100 Subject: can: bittiming: add PWM validation Add can_validate_pwm() to validate the values pwms, pwml and pwml. Error messages are added to each of the checks to inform the user on what went wrong. Refer to those error messages to understand the validation logic. The boundary values CAN_PWM_DECODE_NS (the transceiver minimum decoding margin) and CAN_PWM_NS_MAX (the maximum PWM symbol duration) are hardcoded for the moment. Note that a transceiver capable of bitrates higher than 20 Mbps may be able to handle a CAN_PWM_DECODE_NS below 5 ns. If such transceivers become commercially available, this code could be revisited to make this parameter configurable. For now, leave it static. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-9-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/bittiming.c | 63 +++++++++++++++++++++++++++++++++++++++++ include/linux/can/bittiming.h | 22 ++++++++++++++ 2 files changed, 85 insertions(+) (limited to 'include') diff --git a/drivers/net/can/dev/bittiming.c b/drivers/net/can/dev/bittiming.c index 0b93900b1dfa..8f82418230ce 100644 --- a/drivers/net/can/dev/bittiming.c +++ b/drivers/net/can/dev/bittiming.c @@ -2,6 +2,7 @@ /* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix * Copyright (C) 2006 Andrey Volkov, Varma Electronics * Copyright (C) 2008-2009 Wolfgang Grandegger + * Copyright (c) 2025 Vincent Mailhol */ #include @@ -151,3 +152,65 @@ int can_get_bittiming(const struct net_device *dev, struct can_bittiming *bt, return -EINVAL; } + +int can_validate_pwm_bittiming(const struct net_device *dev, + const struct can_pwm *pwm, + struct netlink_ext_ack *extack) +{ + const struct can_priv *priv = netdev_priv(dev); + u32 xl_bit_time_tqmin = can_bit_time_tqmin(&priv->xl.data_bittiming); + u32 nom_bit_time_tqmin = can_bit_time_tqmin(&priv->bittiming); + u32 pwms_ns = can_tqmin_to_ns(pwm->pwms, priv->clock.freq); + u32 pwml_ns = can_tqmin_to_ns(pwm->pwml, priv->clock.freq); + + if (pwms_ns + pwml_ns > CAN_PWM_NS_MAX) { + NL_SET_ERR_MSG_FMT(extack, + "The PWM symbol duration: %u ns may not exceed %u ns", + pwms_ns + pwml_ns, CAN_PWM_NS_MAX); + return -EINVAL; + } + + if (pwms_ns < CAN_PWM_DECODE_NS) { + NL_SET_ERR_MSG_FMT(extack, + "PWMS: %u ns shall be at least %u ns", + pwms_ns, CAN_PWM_DECODE_NS); + return -EINVAL; + } + + if (pwm->pwms >= pwm->pwml) { + NL_SET_ERR_MSG_FMT(extack, + "PWMS: %u tqmin shall be smaller than PWML: %u tqmin", + pwm->pwms, pwm->pwml); + return -EINVAL; + } + + if (pwml_ns - pwms_ns < 2 * CAN_PWM_DECODE_NS) { + NL_SET_ERR_MSG_FMT(extack, + "At least %u ns shall separate PWMS: %u ns from PMWL: %u ns", + 2 * CAN_PWM_DECODE_NS, pwms_ns, pwml_ns); + return -EINVAL; + } + + if (xl_bit_time_tqmin % (pwm->pwms + pwm->pwml) != 0) { + NL_SET_ERR_MSG_FMT(extack, + "PWM duration: %u tqmin does not divide XL's bit time: %u tqmin", + pwm->pwms + pwm->pwml, xl_bit_time_tqmin); + return -EINVAL; + } + + if (pwm->pwmo >= pwm->pwms + pwm->pwml) { + NL_SET_ERR_MSG_FMT(extack, + "PWMO: %u tqmin can not be greater than PWMS + PWML: %u tqmin", + pwm->pwmo, pwm->pwms + pwm->pwml); + return -EINVAL; + } + + if (nom_bit_time_tqmin % (pwm->pwms + pwm->pwml) != pwm->pwmo) { + NL_SET_ERR_MSG_FMT(extack, + "Can not assemble nominal bit time: %u tqmin out of PWMS + PMWL and PWMO", + nom_bit_time_tqmin); + return -EINVAL; + } + + return 0; +} diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h index 967d76689c4f..2504fafc72e4 100644 --- a/include/linux/can/bittiming.h +++ b/include/linux/can/bittiming.h @@ -87,6 +87,11 @@ struct can_tdc { u32 tdcf; }; +/* The transceiver decoding margin corresponds to t_Decode in ISO 11898-2 */ +#define CAN_PWM_DECODE_NS 5 +/* Maximum PWM symbol duration. Corresponds to t_SymbolNom_MAX - t_Decode */ +#define CAN_PWM_NS_MAX (205 - CAN_PWM_DECODE_NS) + /* * struct can_tdc_const - CAN hardware-dependent constant for * Transmission Delay Compensation @@ -203,6 +208,10 @@ int can_get_bittiming(const struct net_device *dev, struct can_bittiming *bt, const unsigned int bitrate_const_cnt, struct netlink_ext_ack *extack); +int can_validate_pwm_bittiming(const struct net_device *dev, + const struct can_pwm *pwm, + struct netlink_ext_ack *extack); + /* * can_get_relative_tdco() - TDCO relative to the sample point * @@ -245,4 +254,17 @@ static inline unsigned int can_bit_time(const struct can_bittiming *bt) return CAN_SYNC_SEG + bt->prop_seg + bt->phase_seg1 + bt->phase_seg2; } +/* Duration of one bit in minimum time quantum */ +static inline unsigned int can_bit_time_tqmin(const struct can_bittiming *bt) +{ + return can_bit_time(bt) * bt->brp; +} + +/* Convert a duration from minimum a minimum time quantum to nano seconds */ +static inline u32 can_tqmin_to_ns(u32 tqmin, u32 clock_freq) +{ + return DIV_U64_ROUND_CLOSEST(mul_u32_u32(tqmin, NSEC_PER_SEC), + clock_freq); +} + #endif /* !_CAN_BITTIMING_H */ -- cgit From 9892339cf0348730e82383d4de9d9387b9d63925 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Wed, 26 Nov 2025 11:16:11 +0100 Subject: can: calc_bittiming: add PWM calculation Perform the PWM calculation according to CiA recommendations. Note that for databitrates greater than 5 MBPS, tqmin is less than CAN_PWM_NS_MAX (which is defined to 200 nano seconds), consequently, the result of the division: DIV_ROUND_UP(xl_ns, CAN_PWM_NS_MAX) is one and thus the for loop automatically stops on the first iteration giving a single PWM symbol per bit as expected. Because of that, there is no actual need for a separate conditional branch for when the databitrate is greater than 5 MBPS. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-10-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/calc_bittiming.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/can/bittiming.h | 10 ++++++++++ 2 files changed, 46 insertions(+) (limited to 'include') diff --git a/drivers/net/can/dev/calc_bittiming.c b/drivers/net/can/dev/calc_bittiming.c index 394d6974f481..268ec6fa7c49 100644 --- a/drivers/net/can/dev/calc_bittiming.c +++ b/drivers/net/can/dev/calc_bittiming.c @@ -2,6 +2,7 @@ /* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix * Copyright (C) 2006 Andrey Volkov, Varma Electronics * Copyright (C) 2008-2009 Wolfgang Grandegger + * Copyright (C) 2021-2025 Vincent Mailhol */ #include @@ -198,3 +199,38 @@ void can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const, *ctrlmode |= tdc_auto; } } + +int can_calc_pwm(struct net_device *dev, struct netlink_ext_ack *extack) +{ + struct can_priv *priv = netdev_priv(dev); + const struct can_pwm_const *pwm_const = priv->xl.pwm_const; + struct can_pwm *pwm = &priv->xl.pwm; + u32 xl_tqmin = can_bit_time_tqmin(&priv->xl.data_bittiming); + u32 xl_ns = can_tqmin_to_ns(xl_tqmin, priv->clock.freq); + u32 nom_tqmin = can_bit_time_tqmin(&priv->bittiming); + int pwm_per_bit_max = xl_tqmin / (pwm_const->pwms_min + pwm_const->pwml_min); + int pwm_per_bit; + u32 pwm_tqmin; + + /* For 5 MB/s databitrate or greater, xl_ns < CAN_PWM_NS_MAX + * giving us a pwm_per_bit of 1 and the loop immediately breaks + */ + for (pwm_per_bit = DIV_ROUND_UP(xl_ns, CAN_PWM_NS_MAX); + pwm_per_bit <= pwm_per_bit_max; pwm_per_bit++) + if (xl_tqmin % pwm_per_bit == 0) + break; + + if (pwm_per_bit > pwm_per_bit_max) { + NL_SET_ERR_MSG_FMT(extack, + "Can not divide the XL data phase's bit time: %u tqmin into multiple PWM symbols", + xl_tqmin); + return -EINVAL; + } + + pwm_tqmin = xl_tqmin / pwm_per_bit; + pwm->pwms = DIV_ROUND_UP_POW2(pwm_tqmin, 4); + pwm->pwml = pwm_tqmin - pwm->pwms; + pwm->pwmo = nom_tqmin % pwm_tqmin; + + return 0; +} diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h index 2504fafc72e4..726d909e87ce 100644 --- a/include/linux/can/bittiming.h +++ b/include/linux/can/bittiming.h @@ -180,6 +180,8 @@ int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt, void can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const, const struct can_bittiming *dbt, u32 tdc_mask, u32 *ctrlmode, u32 ctrlmode_supported); + +int can_calc_pwm(struct net_device *dev, struct netlink_ext_ack *extack); #else /* !CONFIG_CAN_CALC_BITTIMING */ static inline int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt, @@ -195,6 +197,14 @@ can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const, u32 tdc_mask, u32 *ctrlmode, u32 ctrlmode_supported) { } + +static inline int +can_calc_pwm(struct net_device *dev, struct netlink_ext_ack *extack) +{ + NL_SET_ERR_MSG(extack, + "bit-timing calculation not available: manually provide PWML and PWMS\n"); + return -EINVAL; +} #endif /* CONFIG_CAN_CALC_BITTIMING */ void can_sjw_set_default(struct can_bittiming *bt); -- cgit From 46552323fa6779beb1ea558254dfd56021174c93 Mon Sep 17 00:00:00 2001 From: Vincent Mailhol Date: Wed, 26 Nov 2025 11:16:12 +0100 Subject: can: netlink: add PWM netlink interface When the TMS is switched on, the node uses PWM (Pulse Width Modulation) during the data phase instead of the classic NRZ (Non Return to Zero) encoding. PWM is configured by three parameters: - PWMS: Pulse Width Modulation Short phase - PWML: Pulse Width Modulation Long phase - PWMO: Pulse Width Modulation Offset time For each of these parameters, define three IFLA symbols: - IFLA_CAN_PWM_PWM*_MIN: the minimum allowed value. - IFLA_CAN_PWM_PWM*_MAX: the maximum allowed value. - IFLA_CAN_PWM_PWM*: the runtime value. This results in a total of nine IFLA symbols which are all nested in a parent IFLA_CAN_XL_PWM symbol. IFLA_CAN_PWM_PWM*_MIN and IFLA_CAN_PWM_PWM*_MAX define the range of allowed values and will match the value statically configured by the device in struct can_pwm_const. IFLA_CAN_PWM_PWM* match the runtime values stored in struct can_pwm. Those parameters may only be configured when the tms mode is on. If the PWMS, PWML and PWMO parameters are provided, check that all the needed parameters are present using can_validate_pwm(), then check their value using can_validate_pwm_bittiming(). PWMO defaults to zero if omitted. Otherwise, if CAN_CTRLMODE_XL_TMS is true but none of the PWM parameters are provided, calculate them using can_calc_pwm(). Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-11-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/netlink.c | 192 ++++++++++++++++++++++++++++++++++++++- include/uapi/linux/can/netlink.h | 25 +++++ 2 files changed, 215 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index b2c24439abba..d6b0e686fb11 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -25,6 +25,7 @@ static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = { [IFLA_CAN_XL_DATA_BITTIMING] = { .len = sizeof(struct can_bittiming) }, [IFLA_CAN_XL_DATA_BITTIMING_CONST] = { .len = sizeof(struct can_bittiming_const) }, [IFLA_CAN_XL_TDC] = { .type = NLA_NESTED }, + [IFLA_CAN_XL_PWM] = { .type = NLA_NESTED }, }; static const struct nla_policy can_tdc_policy[IFLA_CAN_TDC_MAX + 1] = { @@ -39,6 +40,18 @@ static const struct nla_policy can_tdc_policy[IFLA_CAN_TDC_MAX + 1] = { [IFLA_CAN_TDC_TDCF] = { .type = NLA_U32 }, }; +static const struct nla_policy can_pwm_policy[IFLA_CAN_PWM_MAX + 1] = { + [IFLA_CAN_PWM_PWMS_MIN] = { .type = NLA_U32 }, + [IFLA_CAN_PWM_PWMS_MAX] = { .type = NLA_U32 }, + [IFLA_CAN_PWM_PWML_MIN] = { .type = NLA_U32 }, + [IFLA_CAN_PWM_PWML_MAX] = { .type = NLA_U32 }, + [IFLA_CAN_PWM_PWMO_MIN] = { .type = NLA_U32 }, + [IFLA_CAN_PWM_PWMO_MAX] = { .type = NLA_U32 }, + [IFLA_CAN_PWM_PWMS] = { .type = NLA_U32 }, + [IFLA_CAN_PWM_PWML] = { .type = NLA_U32 }, + [IFLA_CAN_PWM_PWMO] = { .type = NLA_U32 }, +}; + static int can_validate_bittiming(struct nlattr *data[], struct netlink_ext_ack *extack, int ifla_can_bittiming) @@ -119,6 +132,40 @@ static int can_validate_tdc(struct nlattr *data_tdc, return 0; } +static int can_validate_pwm(struct nlattr *data[], + struct netlink_ext_ack *extack, u32 flags) +{ + struct nlattr *tb_pwm[IFLA_CAN_PWM_MAX + 1]; + int err; + + if (!data[IFLA_CAN_XL_PWM]) + return 0; + + if (!(flags & CAN_CTRLMODE_XL_TMS)) { + NL_SET_ERR_MSG(extack, "PWM requires TMS"); + return -EOPNOTSUPP; + } + + err = nla_parse_nested(tb_pwm, IFLA_CAN_PWM_MAX, data[IFLA_CAN_XL_PWM], + can_pwm_policy, extack); + if (err) + return err; + + if (!tb_pwm[IFLA_CAN_PWM_PWMS] != !tb_pwm[IFLA_CAN_PWM_PWML]) { + NL_SET_ERR_MSG(extack, + "Provide either both PWMS and PWML, or none for automatic calculation"); + return -EOPNOTSUPP; + } + + if (tb_pwm[IFLA_CAN_PWM_PWMO] && + (!tb_pwm[IFLA_CAN_PWM_PWMS] || !tb_pwm[IFLA_CAN_PWM_PWML])) { + NL_SET_ERR_MSG(extack, "PWMO requires both PWMS and PWML"); + return -EOPNOTSUPP; + } + + return 0; +} + static int can_validate_databittiming(struct nlattr *data[], struct netlink_ext_ack *extack, int ifla_can_data_bittiming, u32 flags) @@ -247,6 +294,10 @@ static int can_validate(struct nlattr *tb[], struct nlattr *data[], if (err) return err; + err = can_validate_pwm(data, extack, flags); + if (err) + return err; + return 0; } @@ -322,6 +373,7 @@ static int can_ctrlmode_changelink(struct net_device *dev, sizeof(priv->fd.data_bittiming)); priv->ctrlmode &= ~CAN_CTRLMODE_XL_TDC_MASK; memset(&priv->xl.tdc, 0, sizeof(priv->xl.tdc)); + memset(&priv->xl.pwm, 0, sizeof(priv->xl.pwm)); } can_set_default_mtu(dev); @@ -468,6 +520,76 @@ static int can_dbt_changelink(struct net_device *dev, struct nlattr *data[], return 0; } +static int can_pwm_changelink(struct net_device *dev, + const struct nlattr *pwm_nla, + struct netlink_ext_ack *extack) +{ + struct can_priv *priv = netdev_priv(dev); + const struct can_pwm_const *pwm_const = priv->xl.pwm_const; + struct nlattr *tb_pwm[IFLA_CAN_PWM_MAX + 1]; + struct can_pwm pwm = { 0 }; + int err; + + if (!(priv->ctrlmode & CAN_CTRLMODE_XL_TMS)) + return 0; + + if (!pwm_const) { + NL_SET_ERR_MSG(extack, "The device does not support PWM"); + return -EOPNOTSUPP; + } + + if (!pwm_nla) + return can_calc_pwm(dev, extack); + + err = nla_parse_nested(tb_pwm, IFLA_CAN_PWM_MAX, pwm_nla, + can_pwm_policy, extack); + if (err) + return err; + + if (tb_pwm[IFLA_CAN_PWM_PWMS]) { + pwm.pwms = nla_get_u32(tb_pwm[IFLA_CAN_PWM_PWMS]); + if (pwm.pwms < pwm_const->pwms_min || + pwm.pwms > pwm_const->pwms_max) { + NL_SET_ERR_MSG_FMT(extack, + "PWMS: %u tqmin is out of range: %u...%u", + pwm.pwms, pwm_const->pwms_min, + pwm_const->pwms_max); + return -EINVAL; + } + } + + if (tb_pwm[IFLA_CAN_PWM_PWML]) { + pwm.pwml = nla_get_u32(tb_pwm[IFLA_CAN_PWM_PWML]); + if (pwm.pwml < pwm_const->pwml_min || + pwm.pwml > pwm_const->pwml_max) { + NL_SET_ERR_MSG_FMT(extack, + "PWML: %u tqmin is out of range: %u...%u", + pwm.pwml, pwm_const->pwml_min, + pwm_const->pwml_max); + return -EINVAL; + } + } + + if (tb_pwm[IFLA_CAN_PWM_PWMO]) { + pwm.pwmo = nla_get_u32(tb_pwm[IFLA_CAN_PWM_PWMO]); + if (pwm.pwmo < pwm_const->pwmo_min || + pwm.pwmo > pwm_const->pwmo_max) { + NL_SET_ERR_MSG_FMT(extack, + "PWMO: %u tqmin is out of range: %u...%u", + pwm.pwmo, pwm_const->pwmo_min, + pwm_const->pwmo_max); + return -EINVAL; + } + } + + err = can_validate_pwm_bittiming(dev, &pwm, extack); + if (err) + return err; + + priv->xl.pwm = pwm; + return 0; +} + static int can_changelink(struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) @@ -559,6 +681,9 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[], /* CAN XL */ err = can_dbt_changelink(dev, data, false, extack); + if (err) + return err; + err = can_pwm_changelink(dev, data[IFLA_CAN_XL_PWM], extack); if (err) return err; @@ -647,6 +772,30 @@ static size_t can_ctrlmode_ext_get_size(void) nla_total_size(sizeof(u32)); /* IFLA_CAN_CTRLMODE_SUPPORTED */ } +static size_t can_pwm_get_size(const struct can_pwm_const *pwm_const, + bool pwm_on) +{ + size_t size; + + if (!pwm_const || !pwm_on) + return 0; + + size = nla_total_size(0); /* nest IFLA_CAN_PWM */ + + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_PWM_PWMS_MIN */ + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_PWM_PWMS_MAX */ + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_PWM_PWML_MIN */ + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_PWM_PWML_MAX */ + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_PWM_PWMO_MIN */ + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_PWM_PWMO_MAX */ + + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_PWM_PWMS */ + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_PWM_PWML */ + size += nla_total_size(sizeof(u32)); /* IFLA_CAN_PWM_PWMO */ + + return size; +} + static size_t can_get_size(const struct net_device *dev) { struct can_priv *priv = netdev_priv(dev); @@ -678,6 +827,8 @@ static size_t can_get_size(const struct net_device *dev) size += can_data_bittiming_get_size(&priv->xl, priv->ctrlmode & CAN_CTRLMODE_XL_TDC_MASK); + size += can_pwm_get_size(priv->xl.pwm_const, /* IFLA_CAN_XL_PWM */ + priv->ctrlmode & CAN_CTRLMODE_XL_TMS); return size; } @@ -776,6 +927,42 @@ err_cancel: return -EMSGSIZE; } +static int can_pwm_fill_info(struct sk_buff *skb, const struct can_priv *priv) +{ + const struct can_pwm_const *pwm_const = priv->xl.pwm_const; + const struct can_pwm *pwm = &priv->xl.pwm; + struct nlattr *nest; + + if (!pwm_const) + return 0; + + nest = nla_nest_start(skb, IFLA_CAN_XL_PWM); + if (!nest) + return -EMSGSIZE; + + if (nla_put_u32(skb, IFLA_CAN_PWM_PWMS_MIN, pwm_const->pwms_min) || + nla_put_u32(skb, IFLA_CAN_PWM_PWMS_MAX, pwm_const->pwms_max) || + nla_put_u32(skb, IFLA_CAN_PWM_PWML_MIN, pwm_const->pwml_min) || + nla_put_u32(skb, IFLA_CAN_PWM_PWML_MAX, pwm_const->pwml_max) || + nla_put_u32(skb, IFLA_CAN_PWM_PWMO_MIN, pwm_const->pwmo_min) || + nla_put_u32(skb, IFLA_CAN_PWM_PWMO_MAX, pwm_const->pwmo_max)) + goto err_cancel; + + if (priv->ctrlmode & CAN_CTRLMODE_XL_TMS) { + if (nla_put_u32(skb, IFLA_CAN_PWM_PWMS, pwm->pwms) || + nla_put_u32(skb, IFLA_CAN_PWM_PWML, pwm->pwml) || + nla_put_u32(skb, IFLA_CAN_PWM_PWMO, pwm->pwmo)) + goto err_cancel; + } + + nla_nest_end(skb, nest); + return 0; + +err_cancel: + nla_nest_cancel(skb, nest); + return -EMSGSIZE; +} + static int can_ctrlmode_ext_fill_info(struct sk_buff *skb, const struct can_priv *priv) { @@ -859,9 +1046,10 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev) priv->xl.data_bitrate_const, priv->xl.data_bitrate_const_cnt) || - can_tdc_fill_info(skb, dev, IFLA_CAN_XL_TDC) - ) + can_tdc_fill_info(skb, dev, IFLA_CAN_XL_TDC) || + can_pwm_fill_info(skb, priv) + ) return -EMSGSIZE; return 0; diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h index ebafb091d80f..c30d16746159 100644 --- a/include/uapi/linux/can/netlink.h +++ b/include/uapi/linux/can/netlink.h @@ -5,6 +5,7 @@ * Definitions for the CAN netlink interface * * Copyright (c) 2009 Wolfgang Grandegger + * Copyright (c) 2021-2025 Vincent Mailhol * * 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 @@ -147,6 +148,7 @@ enum { IFLA_CAN_XL_DATA_BITTIMING_CONST, IFLA_CAN_XL_DATA_BITRATE_CONST, IFLA_CAN_XL_TDC, + IFLA_CAN_XL_PWM, /* add new constants above here */ __IFLA_CAN_MAX, @@ -188,6 +190,29 @@ enum { IFLA_CAN_CTRLMODE_MAX = __IFLA_CAN_CTRLMODE - 1 }; +/* + * CAN FD/XL Pulse-Width Modulation (PWM) + * + * Please refer to struct can_pwm_const and can_pwm in + * include/linux/can/bittiming.h for further details. + */ +enum { + IFLA_CAN_PWM_UNSPEC, + IFLA_CAN_PWM_PWMS_MIN, /* u32 */ + IFLA_CAN_PWM_PWMS_MAX, /* u32 */ + IFLA_CAN_PWM_PWML_MIN, /* u32 */ + IFLA_CAN_PWM_PWML_MAX, /* u32 */ + IFLA_CAN_PWM_PWMO_MIN, /* u32 */ + IFLA_CAN_PWM_PWMO_MAX, /* u32 */ + IFLA_CAN_PWM_PWMS, /* u32 */ + IFLA_CAN_PWM_PWML, /* u32 */ + IFLA_CAN_PWM_PWMO, /* u32 */ + + /* add new constants above here */ + __IFLA_CAN_PWM, + IFLA_CAN_PWM_MAX = __IFLA_CAN_PWM - 1 +}; + /* u16 termination range: 1..65535 Ohms */ #define CAN_TERMINATION_DISABLED 0 -- cgit