3.4.7. mcp2515 — CAN BUS chipset

MCP2515 is a CAN controller.

Source code: src/drivers/network/mcp2515.h, src/drivers/network/mcp2515.c

Test code: tst/drivers/hardware/network/mcp2515/main.c

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Defines

MCP2515_SPEED_1000KBPS

MCP2515_SPEED_500KBPS

MCP2515_MODE_NORMAL

MCP2515_MODE_LOOPBACK

Functions

int mcp2515_init(struct mcp2515_driver_t *self_p, struct spi_device_t *spi_p, struct pin_device_t *cs_p, struct exti_device_t *exti_p, void *chin_p, int mode, int speed)

Initialize given driver object.

Return

zero(0) or negative error code.

Parameters

• self_p: Driver object to initialize.
• spi_p: SPI driver to use.
• cs_p: SPI chip select pin.
• exti_p: External interrupt tp use.
• chin_p: Frames received from the hardware are written to this channel.
• mode: Device mode.
• speed: CAN bus speed in kbps.

int mcp2515_start(struct mcp2515_driver_t *self_p)

Starts the CAN device using given driver object.

Return

zero(0) or negative error code.

Parameters

• self_p: Initialized driver object.

int mcp2515_stop(struct mcp2515_driver_t *self_p)

Stops the CAN device referenced by driver object.

Return

zero(0) or negative error code.

Parameters

• self_p: Initialized driver object.

ssize_t mcp2515_read(struct mcp2515_driver_t *self_p, struct mcp2515_frame_t *frame_p)

Read a CAN frame.

Return

zero(0) or negative error code.

Parameters

• self_p: Initialized driver object.
• frame_p: Read frame.

ssize_t mcp2515_write(struct mcp2515_driver_t *self_p, const struct mcp2515_frame_t *frame_p)

Write a CAN frame.

Return

zero(0) or negative error code.

Parameters

• self_p: Initialized driver object.
• frame_p: Frame to write.

struct mcp2515_frame_t

Public Members

uint32_t id

int size

int rtr

uint32_t timestamp

uint8_t data[8]

struct mcp2515_driver_t

Public Functions

mcp2515_driver_t::THRD_STACK(stack, 1024)

Public Members

struct spi_driver_t spi

struct exti_driver_t exti

int mode

int speed

struct chan_t chout

struct chan_t *chin_p

struct sem_t isr_sem

struct sem_t tx_sem