kernel/linux.git/include/linux/can/dev.h, branch v5.15.45

can: dev: provide optional GPIO based termination support

2021-08-19T13:07:03+00:00

For CAN buses to work, a termination resistor has to be present at both ends of the bus. This resistor is usually 120 Ohms, other values may be required for special bus topologies. This patch adds support for a generic GPIO based CAN termination. The resistor value has to be specified via device tree, and it can only be attached to or detached from the bus. By default the termination is not active. Link: https://lore.kernel.org/r/20210818071232.20585-4-o.rempel@pengutronix.de Signed-off-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde

can: dev: reorder struct can_priv members for better packing

2021-03-30T09:14:44+00:00

Save eight bytes of holes on x86-64 architectures by reordering struct can_priv members. Before: $ pahole -C can_priv drivers/net/can/dev/dev.o struct can_priv { struct net_device * dev; /* 0 8 */ struct can_device_stats can_stats; /* 8 24 */ struct can_bittiming bittiming; /* 32 32 */ /* --- cacheline 1 boundary (64 bytes) --- */ struct can_bittiming data_bittiming; /* 64 32 */ const struct can_bittiming_const * bittiming_const; /* 96 8 */ const struct can_bittiming_const * data_bittiming_const; /* 104 8 */ struct can_tdc tdc; /* 112 12 */ /* XXX 4 bytes hole, try to pack */ /* --- cacheline 2 boundary (128 bytes) --- */ const struct can_tdc_const * tdc_const; /* 128 8 */ const u16 * termination_const; /* 136 8 */ unsigned int termination_const_cnt; /* 144 4 */ u16 termination; /* 148 2 */ /* XXX 2 bytes hole, try to pack */ const u32 * bitrate_const; /* 152 8 */ unsigned int bitrate_const_cnt; /* 160 4 */ /* XXX 4 bytes hole, try to pack */ const u32 * data_bitrate_const; /* 168 8 */ unsigned int data_bitrate_const_cnt; /* 176 4 */ u32 bitrate_max; /* 180 4 */ struct can_clock clock; /* 184 4 */ enum can_state state; /* 188 4 */ /* --- cacheline 3 boundary (192 bytes) --- */ u32 ctrlmode; /* 192 4 */ u32 ctrlmode_supported; /* 196 4 */ u32 ctrlmode_static; /* 200 4 */ int restart_ms; /* 204 4 */ struct delayed_work restart_work; /* 208 168 */ /* XXX last struct has 4 bytes of padding */ /* --- cacheline 5 boundary (320 bytes) was 56 bytes ago --- */ int (*do_set_bittiming)(struct net_device *); /* 376 8 */ /* --- cacheline 6 boundary (384 bytes) --- */ int (*do_set_data_bittiming)(struct net_device *); /* 384 8 */ int (*do_set_mode)(struct net_device *, enum can_mode); /* 392 8 */ int (*do_set_termination)(struct net_device *, u16); /* 400 8 */ int (*do_get_state)(const struct net_device *, enum can_state *); /* 408 8 */ int (*do_get_berr_counter)(const struct net_device *, struct can_berr_counter *); /* 416 8 */ unsigned int echo_skb_max; /* 424 4 */ /* XXX 4 bytes hole, try to pack */ struct sk_buff * * echo_skb; /* 432 8 */ /* size: 440, cachelines: 7, members: 31 */ /* sum members: 426, holes: 4, sum holes: 14 */ /* paddings: 1, sum paddings: 4 */ /* last cacheline: 56 bytes */ }; After: $ pahole -C can_priv drivers/net/can/dev/dev.o struct can_priv { struct net_device * dev; /* 0 8 */ struct can_device_stats can_stats; /* 8 24 */ const struct can_bittiming_const * bittiming_const; /* 32 8 */ const struct can_bittiming_const * data_bittiming_const; /* 40 8 */ struct can_bittiming bittiming; /* 48 32 */ /* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */ struct can_bittiming data_bittiming; /* 80 32 */ const struct can_tdc_const * tdc_const; /* 112 8 */ struct can_tdc tdc; /* 120 12 */ /* --- cacheline 2 boundary (128 bytes) was 4 bytes ago --- */ unsigned int bitrate_const_cnt; /* 132 4 */ const u32 * bitrate_const; /* 136 8 */ const u32 * data_bitrate_const; /* 144 8 */ unsigned int data_bitrate_const_cnt; /* 152 4 */ u32 bitrate_max; /* 156 4 */ struct can_clock clock; /* 160 4 */ unsigned int termination_const_cnt; /* 164 4 */ const u16 * termination_const; /* 168 8 */ u16 termination; /* 176 2 */ /* XXX 2 bytes hole, try to pack */ enum can_state state; /* 180 4 */ u32 ctrlmode; /* 184 4 */ u32 ctrlmode_supported; /* 188 4 */ /* --- cacheline 3 boundary (192 bytes) --- */ u32 ctrlmode_static; /* 192 4 */ int restart_ms; /* 196 4 */ struct delayed_work restart_work; /* 200 168 */ /* XXX last struct has 4 bytes of padding */ /* --- cacheline 5 boundary (320 bytes) was 48 bytes ago --- */ int (*do_set_bittiming)(struct net_device *); /* 368 8 */ int (*do_set_data_bittiming)(struct net_device *); /* 376 8 */ /* --- cacheline 6 boundary (384 bytes) --- */ int (*do_set_mode)(struct net_device *, enum can_mode); /* 384 8 */ int (*do_set_termination)(struct net_device *, u16); /* 392 8 */ int (*do_get_state)(const struct net_device *, enum can_state *); /* 400 8 */ int (*do_get_berr_counter)(const struct net_device *, struct can_berr_counter *); /* 408 8 */ unsigned int echo_skb_max; /* 416 4 */ /* XXX 4 bytes hole, try to pack */ struct sk_buff * * echo_skb; /* 424 8 */ /* size: 432, cachelines: 7, members: 31 */ /* sum members: 426, holes: 2, sum holes: 6 */ /* paddings: 1, sum paddings: 4 */ /* last cacheline: 48 bytes */ }; Link: https://lore.kernel.org/r/20210224002008.4158-3-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde

can: add new CAN FD bittiming parameters: Transmitter Delay Compensation (TDC)

2021-03-30T09:14:44+00:00

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. This issue is addressed in ISO 11898-1 section 11.3.3 "Transmitter delay compensation" (TDC). This patch adds two new structures: can_tdc and can_tdc_const in order to implement this TDC. The structures are then added to can_priv. A controller supports TDC if an only if can_priv::tdc_const is not NULL. TDC is active if and only if: - fd flag is on - can_priv::tdc.tdco is not zero. It is the driver responsibility to check those two conditions are met. No new controller modes are introduced (i.e. no CAN_CTRL_MODE_TDC) in order not to be redundant with above logic. The names of the parameters are chosen to match existing CAN controllers specification. References: - Bosch C_CAN FD8: https://www.bosch-semiconductors.com/media/ip_modules/pdf_2/c_can_fd8/users_manual_c_can_fd8_r210_1.pdf - Microchip CAN FD Controller Module: http://ww1.microchip.com/downloads/en/DeviceDoc/MCP251XXFD-CAN-FD-Controller-Module-Family-Reference-Manual-20005678B.pdf - SAM E701/S70/V70/V71 Family: https://www.mouser.com/datasheet/2/268/60001527A-1284321.pdf Link: https://lore.kernel.org/r/20210224002008.4158-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde

can: dev: export can_get_state_str() function

2021-01-27T09:01:46+00:00

The can_get_state_str() function is also relevant to the drivers. Export the symbol and make it visible in the can/dev.h header. Link: https://lore.kernel.org/r/20210119170355.12040-1-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde

can: dev: move netlink related code into seperate file

2021-01-13T08:42:59+00:00

This patch moves the netlink related code of the CAN device infrastructure into a separate file. Reviewed-by: Vincent Mailhol Link: https://lore.kernel.org/r/20210111141930.693847-7-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: dev: move skb related into seperate file

2021-01-13T08:42:59+00:00

This patch moves the skb related code of the CAN device infrastructure into a separate file. Reviewed-by: Vincent Mailhol Link: https://lore.kernel.org/r/20210111141930.693847-6-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: dev: move length related code into seperate file

2021-01-13T08:42:59+00:00

This patch moves all CAN frame length related code of the CAN device infrastructure into a separate file. Reviewed-by: Vincent Mailhol Link: https://lore.kernel.org/r/20210111141930.693847-5-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: dev: move bittiming related code into seperate file

2021-01-13T08:42:58+00:00

This patch moves the bittiming related code of the CAN device infrastructure into a separate file. Reviewed-by: Vincent Mailhol Link: https://lore.kernel.org/r/20210111141930.693847-4-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: drivers: introduce helpers to access Classical CAN DLC values

2020-11-20T11:05:14+00:00

This patch adds the following helper to functions to access Classical CAN DLC values. can_get_cc_dlc(): get the data length code for Classical CAN raw DLC access can_frame_set_cc_len(): set len and len8_dlc value for Classical CAN raw DLC access Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/r/20201110154913.1404582-2-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: rename CAN FD related can_len2dlc and can_dlc2len helpers

2020-11-20T11:05:14+00:00

The helper functions can_len2dlc and can_dlc2len are only relevant for CAN FD data length code (DLC) conversion. To fit the introduced can_cc_dlc2len for Classical CAN we rename: can_dlc2len -> can_fd_dlc2len to get the payload length from the DLC can_len2dlc -> can_fd_len2dlc to get the DLC from the payload length Suggested-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/r/20201110101852.1973-6-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde