diff options
| -rw-r--r-- | drivers/net/can/dev/bittiming.c | 10 | ||||
| -rw-r--r-- | drivers/net/can/usb/etas_es58x/es58x_fd.c | 7 | ||||
| -rw-r--r-- | include/linux/can/bittiming.h | 64 | ||||
| -rw-r--r-- | include/linux/can/dev.h | 4 | ||||
| -rw-r--r-- | include/uapi/linux/can/netlink.h | 2 |
5 files changed, 65 insertions, 22 deletions
diff --git a/drivers/net/can/dev/bittiming.c b/drivers/net/can/dev/bittiming.c index b1b5a82f0829..9dda44c0ae9d 100644 --- a/drivers/net/can/dev/bittiming.c +++ b/drivers/net/can/dev/bittiming.c @@ -182,9 +182,12 @@ void can_calc_tdco(struct net_device *dev) struct can_tdc *tdc = &priv->tdc; const struct can_tdc_const *tdc_const = priv->tdc_const; - if (!tdc_const) + if (!tdc_const || + !(priv->ctrlmode_supported & CAN_CTRLMODE_TDC_AUTO)) return; + priv->ctrlmode &= ~CAN_CTRLMODE_TDC_MASK; + /* As specified in ISO 11898-1 section 11.3.3 "Transmitter * delay compensation" (TDC) is only applicable if data BRP is * one or two. @@ -193,9 +196,10 @@ void can_calc_tdco(struct net_device *dev) /* Reuse "normal" sample point and convert it to time quanta */ u32 sample_point_in_tq = can_bit_time(dbt) * dbt->sample_point / 1000; + if (sample_point_in_tq < tdc_const->tdco_min) + return; tdc->tdco = min(sample_point_in_tq, tdc_const->tdco_max); - } else { - tdc->tdco = 0; + priv->ctrlmode |= CAN_CTRLMODE_TDC_AUTO; } } #endif /* CONFIG_CAN_CALC_BITTIMING */ diff --git a/drivers/net/can/usb/etas_es58x/es58x_fd.c b/drivers/net/can/usb/etas_es58x/es58x_fd.c index af042aa55f59..4f0cae29f4d8 100644 --- a/drivers/net/can/usb/etas_es58x/es58x_fd.c +++ b/drivers/net/can/usb/etas_es58x/es58x_fd.c @@ -428,7 +428,7 @@ static int es58x_fd_enable_channel(struct es58x_priv *priv) es58x_fd_convert_bittiming(&tx_conf_msg.data_bittiming, &priv->can.data_bittiming); - if (priv->can.tdc.tdco) { + if (can_tdc_is_enabled(&priv->can)) { tx_conf_msg.tdc_enabled = 1; tx_conf_msg.tdco = cpu_to_le16(priv->can.tdc.tdco); tx_conf_msg.tdcf = cpu_to_le16(priv->can.tdc.tdcf); @@ -505,8 +505,11 @@ static const struct can_bittiming_const es58x_fd_data_bittiming_const = { * Register" from Microchip. */ static const struct can_tdc_const es58x_tdc_const = { + .tdcv_min = 0, .tdcv_max = 0, /* Manual mode not supported. */ + .tdco_min = 0, .tdco_max = 127, + .tdcf_min = 0, .tdcf_max = 127 }; @@ -523,7 +526,7 @@ const struct es58x_parameters es58x_fd_param = { .clock = {.freq = 80 * CAN_MHZ}, .ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO | - CAN_CTRLMODE_CC_LEN8_DLC, + CAN_CTRLMODE_CC_LEN8_DLC | CAN_CTRLMODE_TDC_AUTO, .tx_start_of_frame = 0xCEFA, /* FACE in little endian */ .rx_start_of_frame = 0xFECA, /* CAFE in little endian */ .tx_urb_cmd_max_len = ES58X_FD_TX_URB_CMD_MAX_LEN, diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h index 9de6e9053e34..9e20260611cc 100644 --- a/include/linux/can/bittiming.h +++ b/include/linux/can/bittiming.h @@ -19,6 +19,9 @@ /* Megahertz */ #define CAN_MHZ 1000000UL +#define CAN_CTRLMODE_TDC_MASK \ + (CAN_CTRLMODE_TDC_AUTO | CAN_CTRLMODE_TDC_MANUAL) + /* * struct can_tdc - CAN FD Transmission Delay Compensation parameters * @@ -33,29 +36,43 @@ * * 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: + * -+----------- one bit ----------+-- TX pin + * |<--- Sample Point --->| + * + * --+----------- one bit ----------+-- RX pin + * |<-------- TDCV -------->| + * |<------- TDCO ------->| + * |<----------- Secondary Sample Point ---------->| + * + * @tdcv: Transmitter Delay Compensation Value. The time needed for + * the signal to propagate, i.e. the distance, in time quanta, + * from the start of the bit on the TX pin to when it is received + * on the RX pin. @tdcv depends on the controller modes: + * + * CAN_CTRLMODE_TDC_AUTO is set: The transceiver dynamically + * measures @tdcv for each transmitted CAN FD frame and the + * value provided here should be ignored. * - * 0: automatic mode. The controller dynamically measures @tdcv - * for each transmitted CAN FD frame. + * CAN_CTRLMODE_TDC_MANUAL is set: use the fixed provided @tdcv + * value. * - * Other values: manual mode. Use the fixed provided value. + * N.B. CAN_CTRLMODE_TDC_AUTO and CAN_CTRLMODE_TDC_MANUAL are + * mutually exclusive. Only one can be set at a time. If both + * CAN_TDC_CTRLMODE_AUTO and CAN_TDC_CTRLMODE_MANUAL are unset, + * TDC is disabled and all the values of this structure should be + * ignored. * * @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 that 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. + * minimum value for the SSP position in time quanta. If the SSP + * position 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; @@ -67,19 +84,32 @@ struct can_tdc { * 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. + * @tdcv_min: Transmitter Delay Compensation Value minimum value. If + * the controller does not support manual mode for tdcv + * (c.f. flag CAN_CTRLMODE_TDC_MANUAL) then this value is + * ignored. + * @tdcv_max: Transmitter Delay Compensation Value maximum value. If + * the controller does not support manual mode for tdcv + * (c.f. flag CAN_CTRLMODE_TDC_MANUAL) then this value is + * ignored. + * + * @tdco_min: Transmitter Delay Compensation Offset minimum value. * @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_min: Transmitter Delay Compensation Filter window minimum + * value. If @tdcf_max is zero, this value is ignored. * @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_min; u32 tdcv_max; + u32 tdco_min; u32 tdco_max; + u32 tdcf_min; u32 tdcf_max; }; diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index 2413253e54c7..6dacbbb41e68 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -96,6 +96,10 @@ struct can_priv { #endif }; +static inline bool can_tdc_is_enabled(const struct can_priv *priv) +{ + return !!(priv->ctrlmode & CAN_CTRLMODE_TDC_MASK); +} /* helper to define static CAN controller features at device creation time */ static inline void can_set_static_ctrlmode(struct net_device *dev, diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h index f730d443b918..004cd09a7d49 100644 --- a/include/uapi/linux/can/netlink.h +++ b/include/uapi/linux/can/netlink.h @@ -101,6 +101,8 @@ struct can_ctrlmode { #define CAN_CTRLMODE_PRESUME_ACK 0x40 /* Ignore missing CAN ACKs */ #define CAN_CTRLMODE_FD_NON_ISO 0x80 /* CAN FD in non-ISO mode */ #define CAN_CTRLMODE_CC_LEN8_DLC 0x100 /* Classic CAN DLC option */ +#define CAN_CTRLMODE_TDC_AUTO 0x200 /* CAN transiver automatically calculates TDCV */ +#define CAN_CTRLMODE_TDC_MANUAL 0x400 /* TDCV is manually set up by user */ /* * CAN device statistics |