Termination resistor documentation
Subsystems (4)
PATCH 1/1 Termination resistor documentation
Add documentation for how to use and setup the switchable termination resistor support for the can-controllers.
--- Documentation/networking/can.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)
Documentation/networking/can.rst +30 -0
@@ -1148,6 +1148,36 @@ tuning on deep embedded systems'. The author is running a MPC603e load without any problems ... +Switchable Termination Resistors +-------------------------------- + +CAN bus requires a specific impedance across the differential pair, +typically provided by two 120Ohm resistors on the farthest nodes of +the bus. Some CAN controllers support activating / deactivating a +termination resistor(s) to provide the correct impedance.:: + + - Query the available resistances: + $ ip -details link show can0 + ... + termination 120 [ 0, 120 + + - Activate the terminating resistor: + $ ip link set dev can0 type can termination 120 + + - Deactivate the terminating resistor: + $ ip link set dev can0 type can termination 0 + +To enable termination resistor support to a can-controller, either +implement in the controller's struct can-priv:: + + termination_const + termination_const_cnt + do_set_termination + +or add gpio control with the device tree entries from +Documentation/devicetree/bindings/net/can/can-controller.yaml + + The Virtual CAN Driver (vcan) -----------------------------
--
2.35.1
Marc Kleine-Budde
maintainerQuoted 15 lines · Daniel S. Trevitz
Add documentation for how to use and setup the switchable termination resistor support for the can-controllers.
Signed-off-by Daniel Trevitz <[email protected]>--- Documentation/networking/can.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)Documentation/networking/can.rst +0
-0@@ -1148,6 +1148,36 @@ tuning on deep embedded systems'. The author is running a MPC603e load without any problems ...
Documentation/networking/can.rst tuning on deep embedded systems'. The author is running a MPC603e · line 1159
Quoted 10 lines
Documentation/networking/can.rst +9
-0+Switchable Termination Resistors +-------------------------------- + +CAN bus requires a specific impedance across the differential pair, +typically provided by two 120Ohm resistors on the farthest nodes of +the bus. Some CAN controllers support activating / deactivating a +termination resistor(s) to provide the correct impedance.:: + + - Query the available resistances:
You need double :: followed by a newline to mark as code.
Documentation/networking/can.rst tuning on deep embedded systems'. The author is running a MPC603e · line 1162
Quoted 3 lines
Documentation/networking/can.rst +3
-0+ $ ip -details link show can0 + ... + termination 120 [ 0, 120
The closing ] is missing, please add it, even if the current ip command doesn't print it. I just noticed it got lost in a cleanup patch in iproute2.
Documentation/networking/can.rst tuning on deep embedded systems'. The author is running a MPC603e · line 1164
Quoted 2 lines
Documentation/networking/can.rst +2
-0+ + - Activate the terminating resistor:
same here
Documentation/networking/can.rst tuning on deep embedded systems'. The author is running a MPC603e · line 1167
Quoted 3 lines
Documentation/networking/can.rst +3
-0+ $ ip link set dev can0 type can termination 120 + + - Deactivate the terminating resistor:
same here
Quoted 5 lines
Documentation/networking/can.rst +5
-0+ $ ip link set dev can0 type can termination 0 + +To enable termination resistor support to a can-controller, either +implement in the controller's struct can-priv:: +
Documentation/networking/can.rst tuning on deep embedded systems'. The author is running a MPC603e · line 1182
Quoted 10 lines
Documentation/networking/can.rst +8
-0+ termination_const + termination_const_cnt + do_set_termination + +or add gpio control with the device tree entries from +Documentation/devicetree/bindings/net/can/can-controller.yaml + + The Virtual CAN Driver (vcan) -----------------------------
Marc
Signature · 4 lines
Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
Quoted 28 lines · EDT Marc Kleine-Budde
Quoted 26 lines · Daniel S. Trevitz
Add documentation for how to use and setup the switchable termination resistor support for the can-controllers.
Signed-off-by Daniel Trevitz <[email protected]>---
Documentation/networking/can.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)(quoted diff) +0
-0
b/Documentation/networking/can.rstindexebc822e605f5..bb39cfa4c502100644Documentation/networking/can.rst +0
-0@@ -1148,6 +1148,36 @@ tuning on deep embedded systems'. The author isrunning a MPC603e>
load without any problems ...Documentation/networking/can.rst +8
-0+Switchable Termination Resistors +-------------------------------- + +CAN bus requires a specific impedance across the differential pair, +typically provided by two 120Ohm resistors on the farthest nodes of +the bus. Some CAN controllers support activating / deactivating a +termination resistor(s) to provide the correct impedance.:: +
Quoted 2 lines
Quoted 1 line
+ - Query the available resistances:
You need double :: followed by a newline to mark as code.
This whole section is a code block; :: is up three lines.
Quoted 8 lines
Documentation/networking/can.rst tuning on deep embedded systems'. The author is running a MPC603e · line 1162
Quoted 4 lines
Documentation/networking/can.rst +3
-0+ $ ip -details link show can0 + ... + termination 120 [ 0, 120The closing ] is missing, please add it, even if the current ip command doesn't print it. I just noticed it got lost in a cleanup patch in iproute2.
Okay
Quoted 26 lines
Documentation/networking/can.rst tuning on deep embedded systems'. The author is running a MPC603e · line 1164
Quoted 4 lines
Documentation/networking/can.rst +2
-0+ + - Activate the terminating resistor:same here
Documentation/networking/can.rst tuning on deep embedded systems'. The author is running a MPC603e
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Documentation/networking/can.rst +3
-0+ $ ip link set dev can0 type can termination 120 + + - Deactivate the terminating resistor:same here
Quoted 14 lines
Documentation/networking/can.rst +13
-0+ $ ip link set dev can0 type can termination 0 + +To enable termination resistor support to a can-controller, either +implement in the controller's struct can-priv:: + + termination_const + termination_const_cnt + do_set_termination + +or add gpio control with the device tree entries from +Documentation/devicetree/bindings/net/can/can-controller.yaml + +
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Quoted 2 lines
The Virtual CAN Driver (vcan)
-----------------------------Marc
-Dan
Marc Kleine-Budde
maintainerQuoted 29 lines · Daniel S. Trevitz
Quoted 28 lines · EDT Marc Kleine-Budde
Quoted 26 lines · Daniel S. Trevitz
Add documentation for how to use and setup the switchable termination resistor support for the can-controllers.
Signed-off-by Daniel Trevitz <[email protected]>---
Documentation/networking/can.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)(quoted diff) +0
-0
b/Documentation/networking/can.rstindexebc822e605f5..bb39cfa4c502100644Documentation/networking/can.rst +0
-0@@ -1148,6 +1148,36 @@ tuning on deep embedded systems'. The author isrunning a MPC603e>
load without any problems ...Documentation/networking/can.rst +8
-0+Switchable Termination Resistors +-------------------------------- + +CAN bus requires a specific impedance across the differential pair, +typically provided by two 120Ohm resistors on the farthest nodes of +the bus. Some CAN controllers support activating / deactivating a +termination resistor(s) to provide the correct impedance.:: +
Quoted 3 lines
Quoted 2 lines
Quoted 1 line
+ - Query the available resistances:
You need double :: followed by a newline to mark as code.
This whole section is a code block; :: is up three lines.
Yes, your're right. What about making only the individual commands code?
Marc
Signature · 4 lines
Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
Quoted 31 lines · EDT Marc Kleine-Budde
Quoted 30 lines · Daniel S. Trevitz
Quoted 29 lines · EDT Marc Kleine-Budde
Quoted 27 lines · Daniel S. Trevitz
Add documentation for how to use and setup the switchable termination resistor support for the can-controllers.
Signed-off-by Daniel Trevitz <[email protected]>---
Documentation/networking/can.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)(quoted diff) +0
-0
b/Documentation/networking/can.rstindexebc822e605f5..bb39cfa4c502100644Documentation/networking/can.rst +0
-0@@ -1148,6 +1148,36 @@ tuning on deep embedded systems'. The author isrunning a MPC603e>
load without any problems ...
Documentation/networking/can.rst +8
-0+Switchable Termination Resistors +-------------------------------- + +CAN bus requires a specific impedance across the differential pair, +typically provided by two 120Ohm resistors on the farthest nodes of +the bus. Some CAN controllers support activating / deactivating a +termination resistor(s) to provide the correct impedance.:: +
Quoted 8 lines
Quoted 4 lines
Quoted 2 lines
Quoted 1 line
+ - Query the available resistances:
You need double :: followed by a newline to mark as code.
This whole section is a code block; :: is up three lines.
Yes, your're right. What about making only the individual commands code?
Marc
Tested, looks fine as individual blocks; v3 coming in hot. -Daniel