GPIO_V2_LINE_SET_CONFIG_IOCTL¶
Name¶
GPIO_V2_LINE_SET_CONFIG_IOCTL - Update the configuration of previously requested lines.
Synopsis¶
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GPIO_V2_LINE_SET_CONFIG_IOCTL¶
int ioctl(int req_fd, GPIO_V2_LINE_SET_CONFIG_IOCTL, struct gpio_v2_line_config *config)
Arguments¶
req_fdThe file descriptor of the GPIO character device, as returned in the
request.fdby GPIO_V2_GET_LINE_IOCTL.configThe new
configurationto apply to the requested lines.
Description¶
Update the configuration of previously requested lines, without releasing the line or introducing potential glitches.
The new configuration must specify a configuration for all requested lines.
The same Configuration Rules and Configuration Support that apply when requesting the lines also apply when updating the line configuration, with the additional restriction that a direction flag must be set to enable reconfiguration. If no direction flag is set in the configuration for a given line then the configuration for that line is left unchanged.
The motivating use case for this command is changing direction of bi-directional lines between input and output, but it may also be used to dynamically control edge detection, or more generally move lines seamlessly from one configuration state to another.
To only change the value of output lines, use GPIO_V2_LINE_SET_VALUES_IOCTL.
Return Value¶
On success 0.
On error -1 and the errno variable is set appropriately.
Common error codes are described in GPIO Error Codes.