Commit | Line | Data |
---|---|---|
3bfd5c5b HS |
1 | Driver for tilt-switches connected via GPIOs |
2 | ============================================ | |
3 | ||
4 | Generic driver to read data from tilt switches connected via gpios. | |
5 | Orientation can be provided by one or more than one tilt switches, | |
6 | i.e. each tilt switch providing one axis, and the number of axes | |
7 | is also not limited. | |
8 | ||
9 | ||
10 | Data structures: | |
11 | ---------------- | |
12 | ||
13 | The array of struct gpio in the gpios field is used to list the gpios | |
14 | that represent the current tilt state. | |
15 | ||
16 | The array of struct gpio_tilt_axis describes the axes that are reported | |
17 | to the input system. The values set therein are used for the | |
18 | input_set_abs_params calls needed to init the axes. | |
19 | ||
20 | The array of struct gpio_tilt_state maps gpio states to the corresponding | |
21 | values to report. The gpio state is represented as a bitfield where the | |
22 | bit-index corresponds to the index of the gpio in the struct gpio array. | |
23 | In the same manner the values stored in the axes array correspond to | |
24 | the elements of the gpio_tilt_axis-array. | |
25 | ||
26 | ||
27 | Example: | |
28 | -------- | |
29 | ||
30 | Example configuration for a single TS1003 tilt switch that rotates around | |
31 | one axis in 4 steps and emitts the current tilt via two GPIOs. | |
32 | ||
33 | static int sg060_tilt_enable(struct device *dev) { | |
34 | /* code to enable the sensors */ | |
35 | }; | |
36 | ||
37 | static void sg060_tilt_disable(struct device *dev) { | |
38 | /* code to disable the sensors */ | |
39 | }; | |
40 | ||
41 | static struct gpio sg060_tilt_gpios[] = { | |
42 | { SG060_TILT_GPIO_SENSOR1, GPIOF_IN, "tilt_sensor1" }, | |
43 | { SG060_TILT_GPIO_SENSOR2, GPIOF_IN, "tilt_sensor2" }, | |
44 | }; | |
45 | ||
46 | static struct gpio_tilt_state sg060_tilt_states[] = { | |
47 | { | |
48 | .gpios = (0 << 1) | (0 << 0), | |
49 | .axes = (int[]) { | |
50 | 0, | |
51 | }, | |
52 | }, { | |
53 | .gpios = (0 << 1) | (1 << 0), | |
54 | .axes = (int[]) { | |
55 | 1, /* 90 degrees */ | |
56 | }, | |
57 | }, { | |
58 | .gpios = (1 << 1) | (1 << 0), | |
59 | .axes = (int[]) { | |
60 | 2, /* 180 degrees */ | |
61 | }, | |
62 | }, { | |
63 | .gpios = (1 << 1) | (0 << 0), | |
64 | .axes = (int[]) { | |
65 | 3, /* 270 degrees */ | |
66 | }, | |
67 | }, | |
68 | }; | |
69 | ||
70 | static struct gpio_tilt_axis sg060_tilt_axes[] = { | |
71 | { | |
72 | .axis = ABS_RY, | |
73 | .min = 0, | |
74 | .max = 3, | |
75 | .fuzz = 0, | |
76 | .flat = 0, | |
77 | }, | |
78 | }; | |
79 | ||
80 | static struct gpio_tilt_platform_data sg060_tilt_pdata= { | |
81 | .gpios = sg060_tilt_gpios, | |
82 | .nr_gpios = ARRAY_SIZE(sg060_tilt_gpios), | |
83 | ||
84 | .axes = sg060_tilt_axes, | |
85 | .nr_axes = ARRAY_SIZE(sg060_tilt_axes), | |
86 | ||
87 | .states = sg060_tilt_states, | |
88 | .nr_states = ARRAY_SIZE(sg060_tilt_states), | |
89 | ||
90 | .debounce_interval = 100, | |
91 | ||
92 | .poll_interval = 1000, | |
93 | .enable = sg060_tilt_enable, | |
94 | .disable = sg060_tilt_disable, | |
95 | }; | |
96 | ||
97 | static struct platform_device sg060_device_tilt = { | |
98 | .name = "gpio-tilt-polled", | |
99 | .id = -1, | |
100 | .dev = { | |
101 | .platform_data = &sg060_tilt_pdata, | |
102 | }, | |
103 | }; |