open.c File Reference

Functions
int	can_open (struct inode *inode, struct file *file)
	int open(const char *pathname, int flags); opens the CAN device for following operations More...

Variables
atomic_t	can_isopen [MAX_CHANNELS]

Detailed Description

Author

Heinz-Jürgen Oertel

Function Documentation

int can_open	(	struct inode *	inode,
		struct file *	file
	)

int open(const char *pathname, int flags); opens the CAN device for following operations

Parameters

pathname	device pathname, usual /dev/can?
flags	is one of O_RDONLY, O_WRONLY or O_RDWR which request opening the file read-only, write-only or read/write, respectively.

The open call is used to "open" the device. Doing a first initialization according the to values in the /proc/sys/Can file system. Additional an ISR function is assigned to the IRQ.

The CLK OUT pin is configured for creating the same frequency like the chips input frequency fclk (XTAL).

If Vendor Option VendOpt is set to 's' the driver performs an hardware reset before initializing the chip.

If compiled with CAN_MAX_OPEN > 1, open() can be called more than once by different processes.

Returns

open return the new file descriptor, or -1 if an error occurred (in which case, errno is set appropriately).

ERRORS

the following errors can occur

• ENXIO the file is a device special file and no corresponding device exists.
• EINVAL illegal minor device number
• EINVAL wrong IO-model format in /proc/sys/Can/IOmodel
• EBUSY IRQ for hardware is not available
• EBUSY I/O region for hardware is not available