diff options
Diffstat (limited to 'include/linux/can')
| -rw-r--r-- | include/linux/can/bittiming.h | 79 | ||||
| -rw-r--r-- | include/linux/can/dev.h | 14 | ||||
| -rw-r--r-- | include/linux/can/skb.h | 3 |
3 files changed, 90 insertions, 6 deletions
diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h index 707575c668f4..ae7a3411167c 100644 --- a/include/linux/can/bittiming.h +++ b/include/linux/can/bittiming.h @@ -1,5 +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> */ #ifndef _CAN_BITTIMING_H @@ -10,9 +11,83 @@ #define CAN_SYNC_SEG 1 + +/* Kilobits and Megabits per second */ +#define CAN_KBPS 1000UL +#define CAN_MBPS 1000000UL + +/* Megahertz */ +#define CAN_MHZ 1000000UL + +/* + * struct can_tdc - CAN FD Transmission Delay Compensation parameters + * + * At high bit rates, the propagation delay from the TX pin to the RX + * pin of the transceiver causes measurement errors: the sample point + * on the RX pin might occur on the previous bit. + * + * To solve this issue, ISO 11898-1 introduces in section 11.3.3 + * "Transmitter delay compensation" a SSP (Secondary Sample Point) + * equal to the distance, in time quanta, from the start of the bit + * time on the TX pin to the actual measurement on the RX pin. + * + * This structure contains the parameters to calculate that SSP. + * + * @tdcv: Transmitter Delay Compensation Value. Distance, in time + * quanta, from when the bit is sent on the TX pin to when it is + * received on the RX pin of the transmitter. Possible options: + * + * O: automatic mode. The controller dynamically measure @tdcv + * for each transmitted CAN FD frame. + * + * Other values: manual mode. Use the fixed provided value. + * + * @tdco: Transmitter Delay Compensation Offset. Offset value, in time + * quanta, defining the distance between the start of the bit + * reception on the RX pin of the transceiver and the SSP + * position such as SSP = @tdcv + @tdco. + * + * If @tdco is zero, then TDC is disabled and both @tdcv and + * @tdcf should be ignored. + * + * @tdcf: Transmitter Delay Compensation Filter window. Defines the + * minimum value for the SSP position in time quanta. If SSP is + * less than @tdcf, then no delay compensations occur and the + * normal sampling point is used instead. The feature is enabled + * if and only if @tdcv is set to zero (automatic mode) and @tdcf + * is configured to a value greater than @tdco. + */ +struct can_tdc { + u32 tdcv; + u32 tdco; + u32 tdcf; +}; + +/* + * struct can_tdc_const - CAN hardware-dependent constant for + * Transmission Delay Compensation + * + * @tdcv_max: Transmitter Delay Compensation Value maximum value. + * Should be set to zero if the controller does not support + * manual mode for tdcv. + * @tdco_max: Transmitter Delay Compensation Offset maximum value. + * Should not be zero. If the controller does not support TDC, + * then the pointer to this structure should be NULL. + * @tdcf_max: Transmitter Delay Compensation Filter window maximum + * value. Should be set to zero if the controller does not + * support this feature. + */ +struct can_tdc_const { + u32 tdcv_max; + u32 tdco_max; + u32 tdcf_max; +}; + #ifdef CONFIG_CAN_CALC_BITTIMING int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, const struct can_bittiming_const *btc); + +void can_calc_tdco(struct net_device *dev); #else /* !CONFIG_CAN_CALC_BITTIMING */ static inline int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, @@ -21,6 +96,10 @@ can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt, netdev_err(dev, "bit-timing calculation not available\n"); return -EINVAL; } + +static inline void can_calc_tdco(struct net_device *dev) +{ +} #endif /* CONFIG_CAN_CALC_BITTIMING */ int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt, diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index ac4d83a1ab81..27b275e463da 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -39,19 +39,23 @@ struct can_priv { struct net_device *dev; struct can_device_stats can_stats; - struct can_bittiming bittiming, data_bittiming; const struct can_bittiming_const *bittiming_const, *data_bittiming_const; - const u16 *termination_const; - unsigned int termination_const_cnt; - u16 termination; - const u32 *bitrate_const; + struct can_bittiming bittiming, data_bittiming; + const struct can_tdc_const *tdc_const; + struct can_tdc tdc; + 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; + unsigned int termination_const_cnt; + const u16 *termination_const; + u16 termination; + enum can_state state; /* CAN controller features - see include/uapi/linux/can/netlink.h */ diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h index d438eb058069..d311bc369a39 100644 --- a/include/linux/can/skb.h +++ b/include/linux/can/skb.h @@ -23,7 +23,8 @@ struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr, unsigned int *frame_len_ptr); unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx, unsigned int *frame_len_ptr); -void can_free_echo_skb(struct net_device *dev, unsigned int idx); +void can_free_echo_skb(struct net_device *dev, unsigned int idx, + unsigned int *frame_len_ptr); struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf); struct sk_buff *alloc_canfd_skb(struct net_device *dev, struct canfd_frame **cfd); |