Based on kernel version 4.10.8. Page generated on 2017-04-01 14:43 EST.
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)