# # For a description of the syntax of this configuration file, # see the file kconfig-language.txt in the NuttX tools repository. # config ARCH_HAVE_CAN_ERRORS bool default n menuconfig CAN bool "CAN Driver Support" default n ---help--- This selection enables building of the "upper-half" CAN driver. See include/nuttx/can/can.h for further CAN driver information. if CAN config CAN_EXTID bool "CAN extended IDs" default n ---help--- Enables support for the 29-bit extended ID. Default Standard 11-bit IDs. config CAN_ERRORS bool "CAN error reporting" default n depends on ARCH_HAVE_CAN_ERRORS ---help--- Support CAN error reporting. If this option is selected then CAN error reporting is enabled. In the event of an error, the ch_error bit will be set in the CAN message and the following message payload will include a more detailed description of certain errors. config CAN_FD bool "CAN FD" default n ---help--- Enables support for the CAN_FD mode. config CAN_FIFOSIZE int "CAN driver I/O buffer size" default 8 ---help--- The size of the circular buffer of CAN messages. Default: 8 config CAN_NPENDINGRTR int "Number of pending RTRs" default 4 ---help--- The size of the list of pending RTR requests. Default: 4 config CAN_TXREADY bool "can_txready interface" default n ---help--- This selection enables the can_txready() interface. This interface is needed only for CAN hardware that supports queueing of outgoing messages in a H/W FIFO. The CAN upper half driver also supports a queue of output messages in a S/W FIFO. Messages are added to that queue when when can_write() is called and removed from the queue in can_txdone() when each TX message is complete. After each message is added to the S/W FIFO, the CAN upper half driver will attempt to send the message by calling into the lower half driver. That send will not be performed if the lower half driver is busy, i.e., if dev_txready() returns false. In that case, the number of messages in the S/W FIFO can grow. If the S/W FIFO becomes full, then can_write() will wait for space in the S/W FIFO. If the CAN hardware does not support a H/W FIFO then busy means that the hardware is actively sending the message and is guaranteed to become non busy (i.e, dev_txready()) when the send transfer completes and can_txdone() is called. So the call to can_txdone() means that the transfer has completed and also that the hardware is ready to accept another transfer. If the CAN hardware supports a H/W FIFO, can_txdone() is not called when the transfer is complete, but rather when the transfer is queued in the H/W FIFO. When the H/W FIFO becomes full, then dev_txready() will report false and the number of queued messages in the S/W FIFO will grow. There is no mechanism in this case to inform the upper half driver when the hardware is again available, when there is again space in the H/W FIFO. can_txdone() will not be called again. If the S/W FIFO becomes full, then the upper half driver will wait for space to become available, but there is no event to awaken it and the driver will hang. Enabling this feature adds support for the can_txready() interface. This function is called from the lower half driver's CAN interrupt handler each time a TX transfer completes. This is a sure indication that the H/W FIFO is no longer full. can_txready() will then awaken the can_write() logic and the hang condition is avoided. choice prompt "TX Ready Work Queue" default CAN_TXREADY_HIPRI depends on CAN_TXREADY config CAN_TXREADY_LOPRI bool "Low-priority work queue" select SCHED_LPWORK config CAN_TXREADY_HIPRI bool "High-priority work queue" select SCHED_HPWORK endchoice # TX Ready Work Queue config CAN_LOOPBACK bool "CAN loopback mode" default n ---help--- A CAN driver may or may not support a loopback mode for testing. If the driver does support loopback mode, the setting will enable it. (If the driver does not, this setting will have no effect). config CAN_NPOLLWAITERS int "Number of poll waiters" default 2 ---help--- The maximum number of threads that may be waiting on the poll method. config CAN_USE_RTR bool "Include RTR in CAN header" default n ---help--- This selection includes RTR bitfield in the CAN header. comment "CAN Bus Controllers:" config CAN_MCP2515 bool "Microchip MCP2515 CAN Bus Controller over SPI" default n depends on SPI select ARCH_HAVE_CAN_ERRORS ---help--- Enable driver support for Microchip MCP2515. if CAN_MCP2515 config MCP2515_BITRATE int "MCP2515 bitrate" default 500000 ---help--- MCP2515 bitrate in bits per second. config MCP2515_PROPSEG int "MCP2515 Propagation Segment TQ" default 2 range 1 8 ---help--- The length of the bit time is Tquanta * (SyncSeg + PropSeg + PhaseSeg1 + PhaseSeg2). config MCP2515_PHASESEG1 int "MCP2515 Phase Segment 1" default 2 range 1 8 ---help--- The length of the bit time is Tquanta * (SyncSeg + PropSeg + PhaseSeg1 + PhaseSeg2). config MCP2515_PHASESEG2 int "MCP2515 Phase Segment 2" default 3 range 2 8 ---help--- The length of the bit time is Tquanta * (SyncSeg + PropSeg + PhaseSeg1 + PhaseSeg2). config MCP2515_SJW int "MCP2515 Synchronization Jump Width" default 1 range 1 4 ---help--- The duration of a synchronization jump is SJW. config MCP2515_CLK_FREQUENCY int "MCP2515 on-board clock frequency" default 8000000 range 1 25000000 config MCP2515_SPI_SCK_FREQUENCY int "MCP2515 SPI SCK Frequency" default 1000000 range 100000 10000000 endif # CAN_MCP2515 menuconfig CAN_SJA1000 tristate "Philips/NXP SJA1000 devices" if CAN_SJA1000 config CAN_SJA1000_BITRATE int "SJA1000 bitrate" default 1000000 ---help--- SJA1000 bit rate. config CAN_SJA1000_SJW int "SJA1000 Synchronization Jump Width" default 1 range 1 4 ---help--- The duration of a synchronization jump is SJW. config CAN_SJA1000_SAM bool "The CAN bus is sampled 3 times" default false ---help--- Recommended for low to medium speed buses to filter spikes on the bus-line. config CAN_SJA1000_SAMPLEP int "SJA1000 CAN sample point (Percentage)" default 87 range 0 100 config CANBUS_REGDEBUG bool "CAN BUS register debug enable." default false config CAN_SJA1000_DEBUG bool "SJA1000 CAN BUS trace debug enable." default false endif # CAN_SJA1000 endif # CAN