GPIO_V2_LINE_GET_VALUES_IOCTL¶
Name¶
GPIO_V2_LINE_GET_VALUES_IOCTL - Get the values of requested lines.
Synopsis¶
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GPIO_V2_LINE_GET_VALUES_IOCTL¶
int ioctl(int req_fd, GPIO_V2_LINE_GET_VALUES_IOCTL, struct gpio_v2_line_values *values)
Arguments¶
req_fdThe file descriptor of the GPIO character device, as returned in the
request.fdby GPIO_V2_GET_LINE_IOCTL.valuesThe
line_valuesto get with themaskset to indicate the subset of requested lines to get.
Description¶
Get the values of requested lines.
The values of both input and output lines may be read.
For output lines, the value returned is driver and configuration dependent and may be either the output buffer (the last requested value set) or the input buffer (the actual level of the line), and depending on the hardware and configuration these may differ.
Return Value¶
On success 0 and the corresponding values.bits
contain the value read.
On error -1 and the errno variable is set appropriately.
Common error codes are described in GPIO Error Codes.