Documentation/input/cma3000_d0x.txt

   1 Kernel driver for CMA3000-D0x
   2 ============================
   3
   4 Supported chips:
   5 * VTI CMA3000-D0x
   6 Datasheet:
   7   CMA3000-D0X Product Family Specification 8281000A.02.pdf
   8   <http://www.vti.fi/en/>
   9
  10 Author: Hemanth V <hemanthv@ti.com>
  11
  12
  13 Description
  14 -----------
  15 CMA3000 Tri-axis accelerometer supports Motion detect, Measurement and
  16 Free fall modes.
  17
  18 Motion Detect Mode: Its the low power mode where interrupts are generated only
  19 when motion exceeds the defined thresholds.
  20
  21 Measurement Mode: This mode is used to read the acceleration data on X,Y,Z
  22 axis and supports 400, 100, 40 Hz sample frequency.
  23
  24 Free fall Mode: This mode is intended to save system resources.
  25
  26 Threshold values: Chip supports defining threshold values for above modes
  27 which includes time and g value. Refer product specifications for more details.
  28
  29 CMA3000 chip supports mutually exclusive I2C and SPI interfaces for
  30 communication, currently the driver supports I2C based communication only.
  31 Initial configuration for bus mode is set in non volatile memory and can later
  32 be modified through bus interface command.
  33
  34 Driver reports acceleration data through input subsystem. It generates ABS_MISC
  35 event with value 1 when free fall is detected.
  36
  37 Platform data need to be configured for initial default values.
  38
  39 Platform Data
  40 -------------
  41 fuzz_x: Noise on X Axis
  42
  43 fuzz_y: Noise on Y Axis
  44
  45 fuzz_z: Noise on Z Axis
  46
  47 g_range: G range in milli g i.e 2000 or 8000
  48
  49 mode: Default Operating mode
  50
  51 mdthr: Motion detect g range threshold value
  52
  53 mdfftmr: Motion detect and free fall time threshold value
  54
  55 ffthr: Free fall g range threshold value
  56
  57 Input Interface
  58 --------------
  59 Input driver version is 1.0.0
  60 Input device ID: bus 0x18 vendor 0x0 product 0x0 version 0x0
  61 Input device name: "cma3000-accelerometer"
  62 Supported events:
  63   Event type 0 (Sync)
  64   Event type 3 (Absolute)
  65     Event code 0 (X)
  66       Value     47
  67       Min    -8000
  68       Max     8000
  69       Fuzz     200
  70     Event code 1 (Y)
  71       Value    -28
  72       Min    -8000
  73       Max     8000
  74       Fuzz     200
  75     Event code 2 (Z)
  76       Value    905
  77       Min    -8000
  78       Max     8000
  79       Fuzz     200
  80     Event code 40 (Misc)
  81       Value      0
  82       Min        0
  83       Max        1
  84   Event type 4 (Misc)
  85
  86
  87 Register/Platform parameters Description
  88 ----------------------------------------
  89
  90 mode:
  91         0: power down mode
  92         1: 100 Hz Measurement mode
  93         2: 400 Hz Measurement mode
  94         3: 40 Hz Measurement mode
  95         4: Motion Detect mode (default)
  96         5: 100 Hz Free fall mode
  97         6: 40 Hz Free fall mode
  98         7: Power off mode
  99
 100 grange:
 101         2000: 2000 mg or 2G Range
 102         8000: 8000 mg or 8G Range
 103
 104 mdthr:
 105         X: X * 71mg (8G Range)
 106         X: X * 18mg (2G Range)
 107
 108 mdfftmr:
 109         X: (X & 0x70) * 100 ms (MDTMR)
 110            (X & 0x0F) * 2.5 ms (FFTMR 400 Hz)
 111            (X & 0x0F) * 10 ms  (FFTMR 100 Hz)
 112
 113 ffthr:
 114        X: (X >> 2) * 18mg (2G Range)
 115        X: (X & 0x0F) * 71 mg (8G Range)