1STRUCT FF_DEVICE(9)             Input Subsystem            STRUCT FF_DEVICE(9)
2
3
4

NAME

6       struct_ff_device - force-feedback part of an input device
7

SYNOPSIS

9       struct ff_device {
10         int (* upload) (struct input_dev *dev, struct ff_effect *effect,struct ff_effect *old);
11         int (* erase) (struct input_dev *dev, int effect_id);
12         int (* playback) (struct input_dev *dev, int effect_id, int value);
13         void (* set_gain) (struct input_dev *dev, u16 gain);
14         void (* set_autocenter) (struct input_dev *dev, u16 magnitude);
15         void (* destroy) (struct ff_device *);
16         void * private;
17         unsigned long ffbit[BITS_TO_LONGS(FF_CNT)];
18         struct mutex mutex;
19         int max_effects;
20         struct ff_effect * effects;
21         struct file * effect_owners[];
22       };
23

MEMBERS

25       upload
26           Called to upload an new effect into device
27
28       erase
29           Called to erase an effect from device
30
31       playback
32           Called to request device to start playing specified effect
33
34       set_gain
35           Called to set specified gain
36
37       set_autocenter
38           Called to auto-center device
39
40       destroy
41           called by input core when parent input device is being destroyed
42
43       private
44           driver-specific data, will be freed automatically
45
46       ffbit[BITS_TO_LONGS(FF_CNT)]
47           bitmap of force feedback capabilities truly supported by device
48           (not emulated like ones in input_dev->ffbit)
49
50       mutex
51           mutex for serializing access to the device
52
53       max_effects
54           maximum number of effects supported by device
55
56       effects
57           pointer to an array of effects currently loaded into device
58
59       effect_owners[]
60           array of effect owners; when file handle owning an effect gets
61           closed the effect is automatically erased
62

DESCRIPTION

64       Every force-feedback device must implement upload and playback methods;
65       erase is optional.  set_gain and set_autocenter need only be
66       implemented if driver sets up FF_GAIN and FF_AUTOCENTER bits.
67
68       Note that playback, set_gain and set_autocenter are called with
69       dev->event_lock spinlock held and interrupts off and thus may not
70       sleep.
71

73Kernel Hackers Manual 2.6.       November 2011             STRUCT FF_DEVICE(9)
Impressum