uart-exchange.c File Reference

#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <termios.h>
#include <unistd.h>
#include "ca821x-generic-exchange.h"
#include "ca821x-posix-util-internal.h"
#include "ca821x-queue.h"
#include "ca821x_api.h"
#include "uart-exchange.h"

Include dependency graph for uart-exchange.c:

Classes
struct	uart_exchange_priv
	Private data for the UART Exchange. More...
struct	uart_device
	struct for representing the contents of CASCODA_UART environment variable More...

Functions
ca_error	uart_exchange_init (ca821x_errorhandler callback, const char *path, struct ca821x_dev *pDeviceRef)
	Initialise the uart exchange, using the supplied errorhandling callback to report any errors back to the application, which can react as required (i.e. More...
void	uart_exchange_deinit (struct ca821x_dev *pDeviceRef)
	Deinitialise the uart exchange, so that it can be reinitialised by another process, or reopened later. More...
ca_error	uart_exchange_enumerate (util_device_found aCallback, void *aContext)
	Function to enumerate all of the UART devices configured (in the CASCODA_UART environment variable), calling aCallback with a struct describing each one. More...
int	uart_exchange_reset (unsigned long resettime, struct ca821x_dev *pDeviceRef)
	Send a hard reset to the ca821x. More...

Function Documentation

uart_exchange_deinit()

void uart_exchange_deinit

(

struct ca821x_dev *

pDeviceRef

)

Deinitialise the uart exchange, so that it can be reinitialised by another process, or reopened later.

Parameters

pDeviceRef

Pointer to initialised ca821x_device_ref struct

uart_exchange_enumerate()

ca_error uart_exchange_enumerate	(	util_device_found	aCallback,
		void *	aContext
	)

Function to enumerate all of the UART devices configured (in the CASCODA_UART environment variable), calling aCallback with a struct describing each one.

The struct passed to aCallback will only be valid for the duration that the function is called. This function will not return until every callback has been called.

Parameters

aCallback	The callback to call with each result
aContext	The generic void pointer to provide to the callback when it is called

Return values

CA_ERROR_SUCCESS	Enumeration successful
CA_ERROR_NOT_FOUND	No devices found

uart_exchange_init()

ca_error uart_exchange_init	(	ca821x_errorhandler	callback,
		const char *	path,
		struct ca821x_dev *	pDeviceRef
	)

Initialise the uart exchange, using the supplied errorhandling callback to report any errors back to the application, which can react as required (i.e.

crash gracefully or attempt to reset the ca821x)

Regarding the path argument, it can be manually selected, or obtained from calling uart_exchange enumerate. The string is a colon-delimited list of comma delimited 'device,baud' pairs. Unlike the USB version of this function, the path argument can be used to specify devices that wouldn't otherwise be available (i.e. they don't need to exist in the CASCODA_UART environment variable).

Parameters

[in]	callback	Function pointer to an error-handling callback (can be NULL)
[in]	path	String representing possible UART devices and baud rates in the form "/dev/ttyS0,115200:/dev/ttyS1,9600:/dev/ttyS2,6000000"
[in]	pDeviceRef	Pointer to initialised ca821x_device_ref struct

Return values

CA_ERROR_SUCCESS	for success
CA_ERROR_NOT_FOUND	for error
CA_ERROR_ALREADY	if the device was already initialised

uart_exchange_reset()

int uart_exchange_reset	(	unsigned long	resettime,
		struct ca821x_dev *	pDeviceRef
	)

Send a hard reset to the ca821x.

This should not be necessary, but is provided in case the ca821x becomes unresponsive to spi.

Parameters

[in]	resettime	The length of time (in ms) to hold the reset pin active for. 1ms is usually a suitable value for this.
[in]	pDeviceRef	Pointer to initialised ca821x_device_ref struct