summaryrefslogtreecommitdiff
path: root/include/linux/can
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/can')
-rw-r--r--include/linux/can/bittiming.h137
-rw-r--r--include/linux/can/dev.h152
-rw-r--r--include/linux/can/dev/peak_canfd.h4
-rw-r--r--include/linux/can/length.h302
-rw-r--r--include/linux/can/rx-offload.h11
5 files changed, 429 insertions, 177 deletions
diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h
index ef0a77173e3c..726d909e87ce 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 <kernel@pengutronix.de>
- * Copyright (c) 2021 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
+ * Copyright (c) 2021-2025 Vincent Mailhol <mailhol@kernel.org>
*/
#ifndef _CAN_BITTIMING_H
@@ -14,8 +14,14 @@
#define CAN_BITRATE_UNSET 0
#define CAN_BITRATE_UNKNOWN (-1U)
-#define CAN_CTRLMODE_TDC_MASK \
+#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_XL_TDC_AUTO)
+#define CAN_CTRLMODE_TDC_MANUAL_MASK \
+ (CAN_CTRLMODE_TDC_MANUAL | CAN_CTRLMODE_XL_TDC_MANUAL)
/*
* struct can_tdc - CAN FD Transmission Delay Compensation parameters
@@ -81,6 +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
@@ -114,34 +125,131 @@ 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;
+ 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);
+ int (*do_get_auto_tdcv)(const struct net_device *dev, u32 *tdcv);
+};
+
#ifdef CONFIG_CAN_CALC_BITTIMING
int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt,
- const struct can_bittiming_const *btc);
+ const struct can_bittiming_const *btc, struct netlink_ext_ack *extack);
void can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const,
const struct can_bittiming *dbt,
- u32 *ctrlmode, u32 ctrlmode_supported);
+ 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,
- const struct can_bittiming_const *btc)
+ 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;
}
static inline void
can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const,
const struct can_bittiming *dbt,
- u32 *ctrlmode, u32 ctrlmode_supported)
+ 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);
+
+int can_sjw_check(const struct net_device *dev, const struct can_bittiming *bt,
+ const struct can_bittiming_const *btc, struct netlink_ext_ack *extack);
+
int can_get_bittiming(const struct net_device *dev, struct can_bittiming *bt,
const struct can_bittiming_const *btc,
const u32 *bitrate_const,
- const unsigned int bitrate_const_cnt);
+ 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
+ *
+ * struct can_tdc::tdco represents the absolute offset from TDCV. Some
+ * controllers use instead an offset relative to the Sample Point (SP)
+ * such that:
+ *
+ * SSP = TDCV + absolute TDCO
+ * = TDCV + SP + relative TDCO
+ *
+ * -+----------- one bit ----------+-- TX pin
+ * |<--- Sample Point --->|
+ *
+ * --+----------- one bit ----------+-- RX pin
+ * |<-------- TDCV -------->|
+ * |<------------------------>| absolute TDCO
+ * |<--- Sample Point --->|
+ * | |<->| relative TDCO
+ * |<------------- Secondary Sample Point ------------>|
+ */
+static inline s32 can_get_relative_tdco(const struct data_bittiming_params *dbt_params)
+{
+ const struct can_bittiming *dbt = &dbt_params->data_bittiming;
+ s32 sample_point_in_tc = (CAN_SYNC_SEG + dbt->prop_seg +
+ dbt->phase_seg1) * dbt->brp;
+
+ return (s32)dbt_params->tdc.tdco - sample_point_in_tc;
+}
/*
* can_bit_time() - Duration of one bit
@@ -156,4 +264,17 @@ 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 */
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 982ba245eb41..f6416a56e95d 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -45,16 +45,11 @@ struct can_priv {
struct net_device *dev;
struct can_device_stats can_stats;
- const struct can_bittiming_const *bittiming_const,
- *data_bittiming_const;
- struct can_bittiming bittiming, data_bittiming;
- const struct can_tdc_const *tdc_const;
- struct can_tdc tdc;
-
+ const struct can_bittiming_const *bittiming_const;
+ struct can_bittiming bittiming;
+ struct data_bittiming_params fd, xl;
unsigned int bitrate_const_cnt;
const u32 *bitrate_const;
- const u32 *data_bitrate_const;
- unsigned int data_bitrate_const_cnt;
u32 bitrate_max;
struct can_clock clock;
@@ -77,69 +72,22 @@ struct can_priv {
struct delayed_work restart_work;
int (*do_set_bittiming)(struct net_device *dev);
- int (*do_set_data_bittiming)(struct net_device *dev);
int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
int (*do_set_termination)(struct net_device *dev, u16 term);
int (*do_get_state)(const struct net_device *dev,
enum can_state *state);
int (*do_get_berr_counter)(const struct net_device *dev,
struct can_berr_counter *bec);
- int (*do_get_auto_tdcv)(const struct net_device *dev, u32 *tdcv);
};
-static inline bool can_tdc_is_enabled(const struct can_priv *priv)
+static inline bool can_fd_tdc_is_enabled(const struct can_priv *priv)
{
- return !!(priv->ctrlmode & CAN_CTRLMODE_TDC_MASK);
+ return !!(priv->ctrlmode & CAN_CTRLMODE_FD_TDC_MASK);
}
-/*
- * can_get_relative_tdco() - TDCO relative to the sample point
- *
- * struct can_tdc::tdco represents the absolute offset from TDCV. Some
- * controllers use instead an offset relative to the Sample Point (SP)
- * such that:
- *
- * SSP = TDCV + absolute TDCO
- * = TDCV + SP + relative TDCO
- *
- * -+----------- one bit ----------+-- TX pin
- * |<--- Sample Point --->|
- *
- * --+----------- one bit ----------+-- RX pin
- * |<-------- TDCV -------->|
- * |<------------------------>| absolute TDCO
- * |<--- Sample Point --->|
- * | |<->| relative TDCO
- * |<------------- Secondary Sample Point ------------>|
- */
-static inline s32 can_get_relative_tdco(const struct can_priv *priv)
+static inline bool can_xl_tdc_is_enabled(const struct can_priv *priv)
{
- const struct can_bittiming *dbt = &priv->data_bittiming;
- s32 sample_point_in_tc = (CAN_SYNC_SEG + dbt->prop_seg +
- dbt->phase_seg1) * dbt->brp;
-
- return (s32)priv->tdc.tdco - sample_point_in_tc;
-}
-
-/* helper to define static CAN controller features at device creation time */
-static inline int __must_check can_set_static_ctrlmode(struct net_device *dev,
- u32 static_mode)
-{
- struct can_priv *priv = netdev_priv(dev);
-
- /* alloc_candev() succeeded => netdev_priv() is valid at this point */
- if (priv->ctrlmode_supported & static_mode) {
- netdev_warn(dev,
- "Controller features can not be supported and static at the same time\n");
- return -EINVAL;
- }
- priv->ctrlmode = static_mode;
-
- /* override MTU which was set by default in can_setup()? */
- if (static_mode & CAN_CTRLMODE_FD)
- dev->mtu = CANFD_MTU;
-
- return 0;
+ return !!(priv->ctrlmode & CAN_CTRLMODE_XL_TDC_MASK);
}
static inline u32 can_get_static_ctrlmode(struct can_priv *priv)
@@ -152,22 +100,6 @@ 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");
- kfree_skb(skb);
- dev->stats.tx_dropped++;
- return true;
- }
-
- return can_dropped_invalid_skb(dev, skb);
-}
-
void can_setup(struct net_device *dev);
struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
@@ -179,14 +111,27 @@ struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
void free_candev(struct net_device *dev);
/* a candev safe wrapper around netdev_priv */
+#if IS_ENABLED(CONFIG_CAN_NETLINK)
struct can_priv *safe_candev_priv(struct net_device *dev);
+#else
+static inline struct can_priv *safe_candev_priv(struct net_device *dev)
+{
+ return NULL;
+}
+#endif
int open_candev(struct net_device *dev);
void close_candev(struct net_device *dev);
-int can_change_mtu(struct net_device *dev, int new_mtu);
-int can_eth_ioctl_hwts(struct net_device *netdev, struct ifreq *ifr, int cmd);
+void can_set_default_mtu(struct net_device *dev);
+int __must_check can_set_static_ctrlmode(struct net_device *dev,
+ u32 static_mode);
+int can_hwtstamp_get(struct net_device *netdev,
+ struct kernel_hwtstamp_config *cfg);
+int can_hwtstamp_set(struct net_device *netdev,
+ struct kernel_hwtstamp_config *cfg,
+ struct netlink_ext_ack *extack);
int can_ethtool_op_get_ts_info_hwts(struct net_device *dev,
- struct ethtool_ts_info *info);
+ struct kernel_ethtool_ts_info *info);
int register_candev(struct net_device *dev);
void unregister_candev(struct net_device *dev);
@@ -195,6 +140,57 @@ int can_restart_now(struct net_device *dev);
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)
+{
+ 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;
+ }
+
+ 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:
+ 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,
+ enum can_state *rx_state);
void can_change_state(struct net_device *dev, struct can_frame *cf,
enum can_state tx_state, enum can_state rx_state);
diff --git a/include/linux/can/dev/peak_canfd.h b/include/linux/can/dev/peak_canfd.h
index f38772fd0c07..d3788a3d0942 100644
--- a/include/linux/can/dev/peak_canfd.h
+++ b/include/linux/can/dev/peak_canfd.h
@@ -2,8 +2,8 @@
/*
* CAN driver for PEAK System micro-CAN based adapters
*
- * Copyright (C) 2003-2011 PEAK System-Technik GmbH
- * Copyright (C) 2011-2013 Stephane Grosjean <s.grosjean@peak-system.com>
+ * Copyright (C) 2003-2025 PEAK System-Technik GmbH
+ * Author: Stéphane Grosjean <stephane.grosjean@hms-networks.com>
*/
#ifndef PUCAN_H
#define PUCAN_H
diff --git a/include/linux/can/length.h b/include/linux/can/length.h
index 6995092b774e..abc978b38f79 100644
--- a/include/linux/can/length.h
+++ b/include/linux/can/length.h
@@ -1,126 +1,258 @@
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2020 Oliver Hartkopp <socketcan@hartkopp.net>
* Copyright (C) 2020 Marc Kleine-Budde <kernel@pengutronix.de>
+ * Copyright (C) 2020, 2023 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
*/
#ifndef _CAN_LENGTH_H
#define _CAN_LENGTH_H
+#include <linux/bits.h>
+#include <linux/can.h>
+#include <linux/can/netlink.h>
+#include <linux/math.h>
+
/*
- * Size of a Classical CAN Standard Frame
+ * Size of a Classical CAN Standard Frame header in bits
*
- * Name of Field Bits
+ * Name of Field Bits
* ---------------------------------------------------------
- * Start-of-frame 1
- * Identifier 11
- * Remote transmission request (RTR) 1
- * Identifier extension bit (IDE) 1
- * Reserved bit (r0) 1
- * Data length code (DLC) 4
- * Data field 0...64
- * CRC 15
- * CRC delimiter 1
- * ACK slot 1
- * ACK delimiter 1
- * End-of-frame (EOF) 7
- * Inter frame spacing 3
+ * Start Of Frame (SOF) 1
+ * Arbitration field:
+ * base ID 11
+ * Remote Transmission Request (RTR) 1
+ * Control field:
+ * IDentifier Extension bit (IDE) 1
+ * FD Format indicator (FDF) 1
+ * Data Length Code (DLC) 4
+ *
+ * including all fields preceding the data field, ignoring bitstuffing
+ */
+#define CAN_FRAME_HEADER_SFF_BITS 19
+
+/*
+ * Size of a Classical CAN Extended Frame header in bits
+ *
+ * Name of Field Bits
+ * ---------------------------------------------------------
+ * Start Of Frame (SOF) 1
+ * Arbitration field:
+ * base ID 11
+ * Substitute Remote Request (SRR) 1
+ * IDentifier Extension bit (IDE) 1
+ * ID extension 18
+ * Remote Transmission Request (RTR) 1
+ * Control field:
+ * FD Format indicator (FDF) 1
+ * Reserved bit (r0) 1
+ * Data length code (DLC) 4
+ *
+ * including all fields preceding the data field, ignoring bitstuffing
+ */
+#define CAN_FRAME_HEADER_EFF_BITS 39
+
+/*
+ * Size of a CAN-FD Standard Frame in bits
*
- * rounded up and ignoring bitstuffing
+ * Name of Field Bits
+ * ---------------------------------------------------------
+ * Start Of Frame (SOF) 1
+ * Arbitration field:
+ * base ID 11
+ * Remote Request Substitution (RRS) 1
+ * Control field:
+ * IDentifier Extension bit (IDE) 1
+ * FD Format indicator (FDF) 1
+ * Reserved bit (res) 1
+ * Bit Rate Switch (BRS) 1
+ * Error Status Indicator (ESI) 1
+ * Data length code (DLC) 4
+ *
+ * including all fields preceding the data field, ignoring bitstuffing
+ */
+#define CANFD_FRAME_HEADER_SFF_BITS 22
+
+/*
+ * Size of a CAN-FD Extended Frame in bits
+ *
+ * Name of Field Bits
+ * ---------------------------------------------------------
+ * Start Of Frame (SOF) 1
+ * Arbitration field:
+ * base ID 11
+ * Substitute Remote Request (SRR) 1
+ * IDentifier Extension bit (IDE) 1
+ * ID extension 18
+ * Remote Request Substitution (RRS) 1
+ * Control field:
+ * FD Format indicator (FDF) 1
+ * Reserved bit (res) 1
+ * Bit Rate Switch (BRS) 1
+ * Error Status Indicator (ESI) 1
+ * Data length code (DLC) 4
+ *
+ * including all fields preceding the data field, ignoring bitstuffing
*/
-#define CAN_FRAME_OVERHEAD_SFF DIV_ROUND_UP(47, 8)
+#define CANFD_FRAME_HEADER_EFF_BITS 41
/*
- * Size of a Classical CAN Extended Frame
+ * Size of a CAN CRC Field in bits
*
* Name of Field Bits
* ---------------------------------------------------------
- * Start-of-frame 1
- * Identifier A 11
- * Substitute remote request (SRR) 1
- * Identifier extension bit (IDE) 1
- * Identifier B 18
- * Remote transmission request (RTR) 1
- * Reserved bits (r1, r0) 2
- * Data length code (DLC) 4
- * Data field 0...64
- * CRC 15
- * CRC delimiter 1
- * ACK slot 1
- * ACK delimiter 1
- * End-of-frame (EOF) 7
- * Inter frame spacing 3
+ * CRC sequence (CRC15) 15
+ * CRC Delimiter 1
*
- * rounded up and ignoring bitstuffing
+ * ignoring bitstuffing
*/
-#define CAN_FRAME_OVERHEAD_EFF DIV_ROUND_UP(67, 8)
+#define CAN_FRAME_CRC_FIELD_BITS 16
/*
- * Size of a CAN-FD Standard Frame
+ * Size of a CAN-FD CRC17 Field in bits (length: 0..16)
*
* Name of Field Bits
* ---------------------------------------------------------
- * Start-of-frame 1
- * Identifier 11
- * Reserved bit (r1) 1
- * Identifier extension bit (IDE) 1
- * Flexible data rate format (FDF) 1
- * Reserved bit (r0) 1
- * Bit Rate Switch (BRS) 1
- * Error Status Indicator (ESI) 1
- * Data length code (DLC) 4
- * Data field 0...512
- * Stuff Bit Count (SBC) 0...16: 4 20...64:5
- * CRC 0...16: 17 20...64:21
- * CRC delimiter (CD) 1
- * ACK slot (AS) 1
- * ACK delimiter (AD) 1
- * End-of-frame (EOF) 7
- * Inter frame spacing 3
- *
- * assuming CRC21, rounded up and ignoring bitstuffing
- */
-#define CANFD_FRAME_OVERHEAD_SFF DIV_ROUND_UP(61, 8)
+ * Stuff Count 4
+ * CRC Sequence (CRC17) 17
+ * CRC Delimiter 1
+ * Fixed stuff bits 6
+ */
+#define CANFD_FRAME_CRC17_FIELD_BITS 28
/*
- * Size of a CAN-FD Extended Frame
+ * Size of a CAN-FD CRC21 Field in bits (length: 20..64)
*
* Name of Field Bits
* ---------------------------------------------------------
- * Start-of-frame 1
- * Identifier A 11
- * Substitute remote request (SRR) 1
- * Identifier extension bit (IDE) 1
- * Identifier B 18
- * Reserved bit (r1) 1
- * Flexible data rate format (FDF) 1
- * Reserved bit (r0) 1
- * Bit Rate Switch (BRS) 1
- * Error Status Indicator (ESI) 1
- * Data length code (DLC) 4
- * Data field 0...512
- * Stuff Bit Count (SBC) 0...16: 4 20...64:5
- * CRC 0...16: 17 20...64:21
- * CRC delimiter (CD) 1
- * ACK slot (AS) 1
- * ACK delimiter (AD) 1
- * End-of-frame (EOF) 7
- * Inter frame spacing 3
- *
- * assuming CRC21, rounded up and ignoring bitstuffing
- */
-#define CANFD_FRAME_OVERHEAD_EFF DIV_ROUND_UP(80, 8)
+ * Stuff Count 4
+ * CRC sequence (CRC21) 21
+ * CRC Delimiter 1
+ * Fixed stuff bits 7
+ */
+#define CANFD_FRAME_CRC21_FIELD_BITS 33
+
+/*
+ * Size of a CAN(-FD) Frame footer in bits
+ *
+ * Name of Field Bits
+ * ---------------------------------------------------------
+ * ACK slot 1
+ * ACK delimiter 1
+ * End Of Frame (EOF) 7
+ *
+ * including all fields following the CRC field
+ */
+#define CAN_FRAME_FOOTER_BITS 9
+
+/*
+ * First part of the Inter Frame Space
+ * (a.k.a. IMF - intermission field)
+ */
+#define CAN_INTERMISSION_BITS 3
+
+/**
+ * can_bitstuffing_len() - Calculate the maximum length with bitstuffing
+ * @destuffed_len: length of a destuffed bit stream
+ *
+ * The worst bit stuffing case is a sequence in which dominant and
+ * recessive bits alternate every four bits:
+ *
+ * Destuffed: 1 1111 0000 1111 0000 1111
+ * Stuffed: 1 1111o 0000i 1111o 0000i 1111o
+ *
+ * Nomenclature
+ *
+ * - "0": dominant bit
+ * - "o": dominant stuff bit
+ * - "1": recessive bit
+ * - "i": recessive stuff bit
+ *
+ * Aside from the first bit, one stuff bit is added every four bits.
+ *
+ * Return: length of the stuffed bit stream in the worst case scenario.
+ */
+#define can_bitstuffing_len(destuffed_len) \
+ (destuffed_len + (destuffed_len - 1) / 4)
+
+#define __can_bitstuffing_len(bitstuffing, destuffed_len) \
+ (bitstuffing ? can_bitstuffing_len(destuffed_len) : \
+ destuffed_len)
+
+#define __can_cc_frame_bits(is_eff, bitstuffing, \
+ intermission, data_len) \
+( \
+ __can_bitstuffing_len(bitstuffing, \
+ (is_eff ? CAN_FRAME_HEADER_EFF_BITS : \
+ CAN_FRAME_HEADER_SFF_BITS) + \
+ (data_len) * BITS_PER_BYTE + \
+ CAN_FRAME_CRC_FIELD_BITS) + \
+ CAN_FRAME_FOOTER_BITS + \
+ (intermission ? CAN_INTERMISSION_BITS : 0) \
+)
+
+#define __can_fd_frame_bits(is_eff, bitstuffing, \
+ intermission, data_len) \
+( \
+ __can_bitstuffing_len(bitstuffing, \
+ (is_eff ? CANFD_FRAME_HEADER_EFF_BITS : \
+ CANFD_FRAME_HEADER_SFF_BITS) + \
+ (data_len) * BITS_PER_BYTE) + \
+ ((data_len) <= 16 ? \
+ CANFD_FRAME_CRC17_FIELD_BITS : \
+ CANFD_FRAME_CRC21_FIELD_BITS) + \
+ CAN_FRAME_FOOTER_BITS + \
+ (intermission ? CAN_INTERMISSION_BITS : 0) \
+)
+
+/**
+ * can_frame_bits() - Calculate the number of bits on the wire in a
+ * CAN frame
+ * @is_fd: true: CAN-FD frame; false: Classical CAN frame.
+ * @is_eff: true: Extended frame; false: Standard frame.
+ * @bitstuffing: true: calculate the bitstuffing worst case; false:
+ * calculate the bitstuffing best case (no dynamic
+ * bitstuffing). CAN-FD's fixed stuff bits are always included.
+ * @intermission: if and only if true, include the inter frame space
+ * assuming no bus idle (i.e. only the intermission). Strictly
+ * speaking, the inter frame space is not part of the
+ * frame. However, it is needed when calculating the delay
+ * between the Start Of Frame of two consecutive frames.
+ * @data_len: length of the data field in bytes. Correspond to
+ * can(fd)_frame->len. Should be zero for remote frames. No
+ * sanitization is done on @data_len and it shall have no side
+ * effects.
+ *
+ * Return: the numbers of bits on the wire of a CAN frame.
+ */
+#define can_frame_bits(is_fd, is_eff, bitstuffing, \
+ intermission, data_len) \
+( \
+ is_fd ? __can_fd_frame_bits(is_eff, bitstuffing, \
+ intermission, data_len) : \
+ __can_cc_frame_bits(is_eff, bitstuffing, \
+ intermission, data_len) \
+)
+
+/*
+ * Number of bytes in a CAN frame
+ * (rounded up, including intermission)
+ */
+#define can_frame_bytes(is_fd, is_eff, bitstuffing, data_len) \
+ DIV_ROUND_UP(can_frame_bits(is_fd, is_eff, bitstuffing, \
+ true, data_len), \
+ BITS_PER_BYTE)
/*
* Maximum size of a Classical CAN frame
- * (rounded up and ignoring bitstuffing)
+ * (rounded up, ignoring bitstuffing but including intermission)
*/
-#define CAN_FRAME_LEN_MAX (CAN_FRAME_OVERHEAD_EFF + CAN_MAX_DLEN)
+#define CAN_FRAME_LEN_MAX can_frame_bytes(false, true, false, CAN_MAX_DLEN)
/*
* Maximum size of a CAN-FD frame
- * (rounded up and ignoring bitstuffing)
+ * (rounded up, ignoring dynamic bitstuffing but including intermission)
*/
-#define CANFD_FRAME_LEN_MAX (CANFD_FRAME_OVERHEAD_EFF + CANFD_MAX_DLEN)
+#define CANFD_FRAME_LEN_MAX can_frame_bytes(true, true, false, CANFD_MAX_DLEN)
/*
* can_cc_dlc2len(value) - convert a given data length code (dlc) of a
diff --git a/include/linux/can/rx-offload.h b/include/linux/can/rx-offload.h
index c205c51d79c9..d29bb4521947 100644
--- a/include/linux/can/rx-offload.h
+++ b/include/linux/can/rx-offload.h
@@ -3,7 +3,7 @@
* linux/can/rx-offload.h
*
* Copyright (c) 2014 David Jander, Protonic Holland
- * Copyright (c) 2014-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
+ * Copyright (c) 2014-2017, 2023 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
*/
#ifndef _CAN_RX_OFFLOAD_H
@@ -44,11 +44,14 @@ int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload,
int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload);
int can_rx_offload_queue_timestamp(struct can_rx_offload *offload,
struct sk_buff *skb, u32 timestamp);
-unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload,
- unsigned int idx, u32 timestamp,
- unsigned int *frame_len_ptr);
+unsigned int can_rx_offload_get_echo_skb_queue_timestamp(struct can_rx_offload *offload,
+ unsigned int idx, u32 timestamp,
+ unsigned int *frame_len_ptr);
int can_rx_offload_queue_tail(struct can_rx_offload *offload,
struct sk_buff *skb);
+unsigned int can_rx_offload_get_echo_skb_queue_tail(struct can_rx_offload *offload,
+ unsigned int idx,
+ unsigned int *frame_len_ptr);
void can_rx_offload_irq_finish(struct can_rx_offload *offload);
void can_rx_offload_threaded_irq_finish(struct can_rx_offload *offload);
void can_rx_offload_del(struct can_rx_offload *offload);
generated by cgit (git 2.34.1) at 2025-12-25 05:01:25 +0000