Input: docs - split input docs into kernel- and user-facing

Split input documentation into several groups: kernel- and user-facing, and
notes about individual device drivers. Move device drivers docs into a
separate subdirectory.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 103 insertions, 0 deletions

diff --git a/Documentation/input/devices/gpio-tilt.rst b/Documentation/input/devices/gpio-tilt.rst
new file mode 100644
index 000000000000..fa6e64570aa7
--- /dev/null
+++ b/Documentation/input/devices/gpio-tilt.rst
@@ -0,0 +1,103 @@
+Driver for tilt-switches connected via GPIOs
+============================================
+
+Generic driver to read data from tilt switches connected via gpios.
+Orientation can be provided by one or more than one tilt switches,
+i.e. each tilt switch providing one axis, and the number of axes
+is also not limited.
+
+
+Data structures
+---------------
+
+The array of struct gpio in the gpios field is used to list the gpios
+that represent the current tilt state.
+
+The array of struct gpio_tilt_axis describes the axes that are reported
+to the input system. The values set therein are used for the
+input_set_abs_params calls needed to init the axes.
+
+The array of struct gpio_tilt_state maps gpio states to the corresponding
+values to report. The gpio state is represented as a bitfield where the
+bit-index corresponds to the index of the gpio in the struct gpio array.
+In the same manner the values stored in the axes array correspond to
+the elements of the gpio_tilt_axis-array.
+
+
+Example
+-------
+
+Example configuration for a single TS1003 tilt switch that rotates around
+one axis in 4 steps and emits the current tilt via two GPIOs::
+
+    static int sg060_tilt_enable(struct device *dev) {
+	    /* code to enable the sensors */
+    };
+
+    static void sg060_tilt_disable(struct device *dev) {
+	    /* code to disable the sensors */
+    };
+
+    static struct gpio sg060_tilt_gpios[] = {
+	    { SG060_TILT_GPIO_SENSOR1, GPIOF_IN, "tilt_sensor1" },
+	    { SG060_TILT_GPIO_SENSOR2, GPIOF_IN, "tilt_sensor2" },
+    };
+
+    static struct gpio_tilt_state sg060_tilt_states[] = {
+	    {
+		    .gpios = (0 << 1) | (0 << 0),
+		    .axes = (int[]) {
+			    0,
+		    },
+	    }, {
+		    .gpios = (0 << 1) | (1 << 0),
+		    .axes = (int[]) {
+			    1, /* 90 degrees */
+		    },
+	    }, {
+		    .gpios = (1 << 1) | (1 << 0),
+		    .axes = (int[]) {
+			    2, /* 180 degrees */
+		    },
+	    }, {
+		    .gpios = (1 << 1) | (0 << 0),
+		    .axes = (int[]) {
+			    3, /* 270 degrees */
+		    },
+	    },
+    };
+
+    static struct gpio_tilt_axis sg060_tilt_axes[] = {
+	    {
+		    .axis = ABS_RY,
+		    .min = 0,
+		    .max = 3,
+		    .fuzz = 0,
+		    .flat = 0,
+	    },
+    };
+
+    static struct gpio_tilt_platform_data sg060_tilt_pdata= {
+	    .gpios = sg060_tilt_gpios,
+	    .nr_gpios = ARRAY_SIZE(sg060_tilt_gpios),
+
+	    .axes = sg060_tilt_axes,
+	    .nr_axes = ARRAY_SIZE(sg060_tilt_axes),
+
+	    .states = sg060_tilt_states,
+	    .nr_states = ARRAY_SIZE(sg060_tilt_states),
+
+	    .debounce_interval = 100,
+
+	    .poll_interval = 1000,
+	    .enable = sg060_tilt_enable,
+	    .disable = sg060_tilt_disable,
+    };
+
+    static struct platform_device sg060_device_tilt = {
+	    .name = "gpio-tilt-polled",
+	    .id = -1,
+	    .dev = {
+		    .platform_data = &sg060_tilt_pdata,
+	    },
+    };