linux-stable/include/linux/input/adxl34x.h
Michael Tandy 5eb9f900e5 Input: adxl34x - documentation cleanup
This patch clarifies a few bits of documentation in the header file
for the adxl34x driver.

Signed-off-by: Michael Tandy <lkml@mkt.me.uk>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2011-09-20 22:46:32 -07:00

356 lines
11 KiB
C

/*
* include/linux/input/adxl34x.h
*
* Digital Accelerometer characteristics are highly application specific
* and may vary between boards and models. The platform_data for the
* device's "struct device" holds this information.
*
* Copyright 2009 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#ifndef __LINUX_INPUT_ADXL34X_H__
#define __LINUX_INPUT_ADXL34X_H__
struct adxl34x_platform_data {
/*
* X,Y,Z Axis Offset:
* offer user offset adjustments in twoscompliment
* form with a scale factor of 15.6 mg/LSB (i.e. 0x7F = +2 g)
*/
s8 x_axis_offset;
s8 y_axis_offset;
s8 z_axis_offset;
/*
* TAP_X/Y/Z Enable: Setting TAP_X, Y, or Z Enable enables X,
* Y, or Z participation in Tap detection. A '0' excludes the
* selected axis from participation in Tap detection.
* Setting the SUPPRESS bit suppresses Double Tap detection if
* acceleration greater than tap_threshold is present during the
* tap_latency period, i.e. after the first tap but before the
* opening of the second tap window.
*/
#define ADXL_SUPPRESS (1 << 3)
#define ADXL_TAP_X_EN (1 << 2)
#define ADXL_TAP_Y_EN (1 << 1)
#define ADXL_TAP_Z_EN (1 << 0)
u8 tap_axis_control;
/*
* tap_threshold:
* holds the threshold value for tap detection/interrupts.
* The data format is unsigned. The scale factor is 62.5 mg/LSB
* (i.e. 0xFF = +16 g). A zero value may result in undesirable
* behavior if Tap/Double Tap is enabled.
*/
u8 tap_threshold;
/*
* tap_duration:
* is an unsigned time value representing the maximum
* time that an event must be above the tap_threshold threshold
* to qualify as a tap event. The scale factor is 625 us/LSB. A zero
* value will prevent Tap/Double Tap functions from working.
*/
u8 tap_duration;
/*
* tap_latency:
* is an unsigned time value representing the wait time
* from the detection of a tap event to the opening of the time
* window tap_window for a possible second tap event. The scale
* factor is 1.25 ms/LSB. A zero value will disable the Double Tap
* function.
*/
u8 tap_latency;
/*
* tap_window:
* is an unsigned time value representing the amount
* of time after the expiration of tap_latency during which a second
* tap can begin. The scale factor is 1.25 ms/LSB. A zero value will
* disable the Double Tap function.
*/
u8 tap_window;
/*
* act_axis_control:
* X/Y/Z Enable: A '1' enables X, Y, or Z participation in activity
* or inactivity detection. A '0' excludes the selected axis from
* participation. If all of the axes are excluded, the function is
* disabled.
* AC/DC: A '0' = DC coupled operation and a '1' = AC coupled
* operation. In DC coupled operation, the current acceleration is
* compared with activity_threshold and inactivity_threshold directly
* to determine whether activity or inactivity is detected. In AC
* coupled operation for activity detection, the acceleration value
* at the start of activity detection is taken as a reference value.
* New samples of acceleration are then compared to this
* reference value and if the magnitude of the difference exceeds
* activity_threshold the device will trigger an activity interrupt. In
* AC coupled operation for inactivity detection, a reference value
* is used again for comparison and is updated whenever the
* device exceeds the inactivity threshold. Once the reference
* value is selected, the device compares the magnitude of the
* difference between the reference value and the current
* acceleration with inactivity_threshold. If the difference is below
* inactivity_threshold for a total of inactivity_time, the device is
* considered inactive and the inactivity interrupt is triggered.
*/
#define ADXL_ACT_ACDC (1 << 7)
#define ADXL_ACT_X_EN (1 << 6)
#define ADXL_ACT_Y_EN (1 << 5)
#define ADXL_ACT_Z_EN (1 << 4)
#define ADXL_INACT_ACDC (1 << 3)
#define ADXL_INACT_X_EN (1 << 2)
#define ADXL_INACT_Y_EN (1 << 1)
#define ADXL_INACT_Z_EN (1 << 0)
u8 act_axis_control;
/*
* activity_threshold:
* holds the threshold value for activity detection.
* The data format is unsigned. The scale factor is
* 62.5 mg/LSB. A zero value may result in undesirable behavior if
* Activity interrupt is enabled.
*/
u8 activity_threshold;
/*
* inactivity_threshold:
* holds the threshold value for inactivity
* detection. The data format is unsigned. The scale
* factor is 62.5 mg/LSB. A zero value may result in undesirable
* behavior if Inactivity interrupt is enabled.
*/
u8 inactivity_threshold;
/*
* inactivity_time:
* is an unsigned time value representing the
* amount of time that acceleration must be below the value in
* inactivity_threshold for inactivity to be declared. The scale factor
* is 1 second/LSB. Unlike the other interrupt functions, which
* operate on unfiltered data, the inactivity function operates on the
* filtered output data. At least one output sample must be
* generated for the inactivity interrupt to be triggered. This will
* result in the function appearing un-responsive if the
* inactivity_time register is set with a value less than the time
* constant of the Output Data Rate. A zero value will result in an
* interrupt when the output data is below inactivity_threshold.
*/
u8 inactivity_time;
/*
* free_fall_threshold:
* holds the threshold value for Free-Fall detection.
* The data format is unsigned. The root-sum-square(RSS) value
* of all axes is calculated and compared to the value in
* free_fall_threshold to determine if a free fall event may be
* occurring. The scale factor is 62.5 mg/LSB. A zero value may
* result in undesirable behavior if Free-Fall interrupt is
* enabled. Values between 300 and 600 mg (0x05 to 0x09) are
* recommended.
*/
u8 free_fall_threshold;
/*
* free_fall_time:
* is an unsigned time value representing the minimum
* time that the RSS value of all axes must be less than
* free_fall_threshold to generate a Free-Fall interrupt. The
* scale factor is 5 ms/LSB. A zero value may result in
* undesirable behavior if Free-Fall interrupt is enabled.
* Values between 100 to 350 ms (0x14 to 0x46) are recommended.
*/
u8 free_fall_time;
/*
* data_rate:
* Selects device bandwidth and output data rate.
* RATE = 3200 Hz / (2^(15 - x)). Default value is 0x0A, or 100 Hz
* Output Data Rate. An Output Data Rate should be selected that
* is appropriate for the communication protocol and frequency
* selected. Selecting too high of an Output Data Rate with a low
* communication speed will result in samples being discarded.
*/
u8 data_rate;
/*
* data_range:
* FULL_RES: When this bit is set with the device is
* in Full-Resolution Mode, where the output resolution increases
* with RANGE to maintain a 4 mg/LSB scale factor. When this
* bit is cleared the device is in 10-bit Mode and RANGE determine the
* maximum g-Range and scale factor.
*/
#define ADXL_FULL_RES (1 << 3)
#define ADXL_RANGE_PM_2g 0
#define ADXL_RANGE_PM_4g 1
#define ADXL_RANGE_PM_8g 2
#define ADXL_RANGE_PM_16g 3
u8 data_range;
/*
* low_power_mode:
* A '0' = Normal operation and a '1' = Reduced
* power operation with somewhat higher noise.
*/
u8 low_power_mode;
/*
* power_mode:
* LINK: A '1' with both the activity and inactivity functions
* enabled will delay the start of the activity function until
* inactivity is detected. Once activity is detected, inactivity
* detection will begin and prevent the detection of activity. This
* bit serially links the activity and inactivity functions. When '0'
* the inactivity and activity functions are concurrent. Additional
* information can be found in the ADXL34x datasheet's Application
* section under Link Mode.
* AUTO_SLEEP: A '1' sets the ADXL34x to switch to Sleep Mode
* when inactivity (acceleration has been below inactivity_threshold
* for at least inactivity_time) is detected and the LINK bit is set.
* A '0' disables automatic switching to Sleep Mode. See the
* Sleep Bit section of the ADXL34x datasheet for more information.
*/
#define ADXL_LINK (1 << 5)
#define ADXL_AUTO_SLEEP (1 << 4)
u8 power_mode;
/*
* fifo_mode:
* BYPASS The FIFO is bypassed
* FIFO FIFO collects up to 32 values then stops collecting data
* STREAM FIFO holds the last 32 data values. Once full, the FIFO's
* oldest data is lost as it is replaced with newer data
*
* DEFAULT should be ADXL_FIFO_STREAM
*/
#define ADXL_FIFO_BYPASS 0
#define ADXL_FIFO_FIFO 1
#define ADXL_FIFO_STREAM 2
u8 fifo_mode;
/*
* watermark:
* The Watermark feature can be used to reduce the interrupt load
* of the system. The FIFO fills up to the value stored in watermark
* [1..32] and then generates an interrupt.
* A '0' disables the watermark feature.
*/
u8 watermark;
/*
* When acceleration measurements are received from the ADXL34x
* events are sent to the event subsystem. The following settings
* select the event type and event code for new x, y and z axis data
* respectively.
*/
u32 ev_type; /* EV_ABS or EV_REL */
u32 ev_code_x; /* ABS_X,Y,Z or REL_X,Y,Z */
u32 ev_code_y; /* ABS_X,Y,Z or REL_X,Y,Z */
u32 ev_code_z; /* ABS_X,Y,Z or REL_X,Y,Z */
/*
* A valid BTN or KEY Code; use tap_axis_control to disable
* event reporting
*/
u32 ev_code_tap[3]; /* EV_KEY {X-Axis, Y-Axis, Z-Axis} */
/*
* A valid BTN or KEY Code for Free-Fall or Activity enables
* input event reporting. A '0' disables the Free-Fall or
* Activity reporting.
*/
u32 ev_code_ff; /* EV_KEY */
u32 ev_code_act_inactivity; /* EV_KEY */
/*
* Use ADXL34x INT2 pin instead of INT1 pin for interrupt output
*/
u8 use_int2;
/*
* ADXL346 only ORIENTATION SENSING feature
* The orientation function of the ADXL346 reports both 2-D and
* 3-D orientation concurrently.
*/
#define ADXL_EN_ORIENTATION_2D 1
#define ADXL_EN_ORIENTATION_3D 2
#define ADXL_EN_ORIENTATION_2D_3D 3
u8 orientation_enable;
/*
* The width of the deadzone region between two or more
* orientation positions is determined by setting the Deadzone
* value. The deadzone region size can be specified with a
* resolution of 3.6deg. The deadzone angle represents the total
* angle where the orientation is considered invalid.
*/
#define ADXL_DEADZONE_ANGLE_0p0 0 /* !!!0.0 [deg] */
#define ADXL_DEADZONE_ANGLE_3p6 1 /* 3.6 [deg] */
#define ADXL_DEADZONE_ANGLE_7p2 2 /* 7.2 [deg] */
#define ADXL_DEADZONE_ANGLE_10p8 3 /* 10.8 [deg] */
#define ADXL_DEADZONE_ANGLE_14p4 4 /* 14.4 [deg] */
#define ADXL_DEADZONE_ANGLE_18p0 5 /* 18.0 [deg] */
#define ADXL_DEADZONE_ANGLE_21p6 6 /* 21.6 [deg] */
#define ADXL_DEADZONE_ANGLE_25p2 7 /* 25.2 [deg] */
u8 deadzone_angle;
/*
* To eliminate most human motion such as walking or shaking,
* a Divisor value should be selected to effectively limit the
* orientation bandwidth. Set the depth of the filter used to
* low-pass filter the measured acceleration for stable
* orientation sensing
*/
#define ADXL_LP_FILTER_DIVISOR_2 0
#define ADXL_LP_FILTER_DIVISOR_4 1
#define ADXL_LP_FILTER_DIVISOR_8 2
#define ADXL_LP_FILTER_DIVISOR_16 3
#define ADXL_LP_FILTER_DIVISOR_32 4
#define ADXL_LP_FILTER_DIVISOR_64 5
#define ADXL_LP_FILTER_DIVISOR_128 6
#define ADXL_LP_FILTER_DIVISOR_256 7
u8 divisor_length;
u32 ev_codes_orient_2d[4]; /* EV_KEY {+X, -X, +Y, -Y} */
u32 ev_codes_orient_3d[6]; /* EV_KEY {+Z, +Y, +X, -X, -Y, -Z} */
};
#endif