|
Enumerations | |
| enum | { GPIOD_LINE_DIRECTION_INPUT = 1, GPIOD_LINE_DIRECTION_OUTPUT } |
| Possible direction settings. More... | |
| enum | { GPIOD_LINE_ACTIVE_STATE_HIGH = 1, GPIOD_LINE_ACTIVE_STATE_LOW } |
| Possible active state settings. More... | |
Functions | |
| unsigned int | gpiod_line_offset (struct gpiod_line *line) GPIOD_API |
| Read the GPIO line offset. More... | |
| const char * | gpiod_line_name (struct gpiod_line *line) GPIOD_API |
| Read the GPIO line name. More... | |
| const char * | gpiod_line_consumer (struct gpiod_line *line) GPIOD_API |
| Read the GPIO line consumer name. More... | |
| int | gpiod_line_direction (struct gpiod_line *line) GPIOD_API |
| Read the GPIO line direction setting. More... | |
| int | gpiod_line_active_state (struct gpiod_line *line) GPIOD_API |
| Read the GPIO line active state setting. More... | |
| bool | gpiod_line_is_used (struct gpiod_line *line) GPIOD_API |
| Check if the line is currently in use. More... | |
| bool | gpiod_line_is_open_drain (struct gpiod_line *line) GPIOD_API |
| Check if the line is an open-drain GPIO. More... | |
| bool | gpiod_line_is_open_source (struct gpiod_line *line) GPIOD_API |
| Check if the line is an open-source GPIO. More... | |
| int | gpiod_line_update (struct gpiod_line *line) GPIOD_API |
| Re-read the line info. More... | |
| bool | gpiod_line_needs_update (struct gpiod_line *line) GPIOD_API |
| Check if the line info needs to be updated. More... | |
Detailed Description
Enumeration Type Documentation
◆ anonymous enum
| anonymous enum |
◆ anonymous enum
| anonymous enum |
Function Documentation
◆ gpiod_line_active_state()
| int gpiod_line_active_state | ( | struct gpiod_line * | line | ) |
Read the GPIO line active state setting.
- Parameters
-
line GPIO line object.
- Returns
- Returns GPIOD_ACTIVE_STATE_HIGH or GPIOD_ACTIVE_STATE_LOW.
◆ gpiod_line_consumer()
| const char* gpiod_line_consumer | ( | struct gpiod_line * | line | ) |
Read the GPIO line consumer name.
- Parameters
-
line GPIO line object.
- Returns
- Name of the GPIO consumer name as it is represented in the kernel. This routine returns a pointer to a null-terminated string or NULL if the line is not used.
◆ gpiod_line_direction()
| int gpiod_line_direction | ( | struct gpiod_line * | line | ) |
Read the GPIO line direction setting.
- Parameters
-
line GPIO line object.
- Returns
- Returns GPIOD_DIRECTION_INPUT or GPIOD_DIRECTION_OUTPUT.
◆ gpiod_line_is_open_drain()
| bool gpiod_line_is_open_drain | ( | struct gpiod_line * | line | ) |
Check if the line is an open-drain GPIO.
- Parameters
-
line GPIO line object.
- Returns
- True if the line is an open-drain GPIO, false otherwise.
◆ gpiod_line_is_open_source()
| bool gpiod_line_is_open_source | ( | struct gpiod_line * | line | ) |
Check if the line is an open-source GPIO.
- Parameters
-
line GPIO line object.
- Returns
- True if the line is an open-source GPIO, false otherwise.
◆ gpiod_line_is_used()
| bool gpiod_line_is_used | ( | struct gpiod_line * | line | ) |
Check if the line is currently in use.
- Parameters
-
line GPIO line object.
- Returns
- True if the line is in use, false otherwise.
The user space can't know exactly why a line is busy. It may have been requested by another process or hogged by the kernel. It only matters that the line is used and we can't request it.
◆ gpiod_line_name()
| const char* gpiod_line_name | ( | struct gpiod_line * | line | ) |
Read the GPIO line name.
- Parameters
-
line GPIO line object.
- Returns
- Name of the GPIO line as it is represented in the kernel. This routine returns a pointer to a null-terminated string or NULL if the line is unnamed.
◆ gpiod_line_needs_update()
| bool gpiod_line_needs_update | ( | struct gpiod_line * | line | ) |
Check if the line info needs to be updated.
- Parameters
-
line GPIO line object.
- Returns
- Returns false if the line is up-to-date. True otherwise.
The line is updated by calling gpiod_line_update() from within gpiod_chip_get_line() and on every line request/release. However: an error returned from gpiod_line_update() only breaks the execution of the former. The request/release routines only set the internal up-to-date flag to false and continue their execution. This routine allows to check if a line info update failed at some point and we should call gpiod_line_update() explicitly.
◆ gpiod_line_offset()
| unsigned int gpiod_line_offset | ( | struct gpiod_line * | line | ) |
Read the GPIO line offset.
- Parameters
-
line GPIO line object.
- Returns
- Line offset.
◆ gpiod_line_update()
| int gpiod_line_update | ( | struct gpiod_line * | line | ) |
Re-read the line info.
- Parameters
-
line GPIO line object.
- Returns
- 0 is the operation succeeds. In case of an error this routine returns -1 and sets the last error number.
The line info is initially retrieved from the kernel by gpiod_chip_get_line(). Users can use this line to manually re-read the line info.
