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Diffstat (limited to 'Documentation/input')
| -rw-r--r-- | Documentation/input/cma3000_d0x.txt | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/Documentation/input/cma3000_d0x.txt b/Documentation/input/cma3000_d0x.txt new file mode 100644 index 00000000000..29d088db4af --- /dev/null +++ b/Documentation/input/cma3000_d0x.txt @@ -0,0 +1,115 @@ +Kernel driver for CMA3000-D0x +============================ + +Supported chips: +* VTI CMA3000-D0x +Datasheet: + CMA3000-D0X Product Family Specification 8281000A.02.pdf + <http://www.vti.fi/en/> + +Author: Hemanth V <hemanthv@ti.com> + + +Description +----------- +CMA3000 Tri-axis accelerometer supports Motion detect, Measurement and +Free fall modes. + +Motion Detect Mode: Its the low power mode where interrupts are generated only +when motion exceeds the defined thresholds. + +Measurement Mode: This mode is used to read the acceleration data on X,Y,Z +axis and supports 400, 100, 40 Hz sample frequency. + +Free fall Mode: This mode is intended to save system resources. + +Threshold values: Chip supports defining threshold values for above modes +which includes time and g value. Refer product specifications for more details. + +CMA3000 chip supports mutually exclusive I2C and SPI interfaces for +communication, currently the driver supports I2C based communication only. +Initial configuration for bus mode is set in non volatile memory and can later +be modified through bus interface command. + +Driver reports acceleration data through input subsystem. It generates ABS_MISC +event with value 1 when free fall is detected. + +Platform data need to be configured for initial default values. + +Platform Data +------------- +fuzz_x: Noise on X Axis + +fuzz_y: Noise on Y Axis + +fuzz_z: Noise on Z Axis + +g_range: G range in milli g i.e 2000 or 8000 + +mode: Default Operating mode + +mdthr: Motion detect g range threshold value + +mdfftmr: Motion detect and free fall time threshold value + +ffthr: Free fall g range threshold value + +Input Interface +-------------- +Input driver version is 1.0.0 +Input device ID: bus 0x18 vendor 0x0 product 0x0 version 0x0 +Input device name: "cma3000-accelerometer" +Supported events: + Event type 0 (Sync) + Event type 3 (Absolute) + Event code 0 (X) + Value 47 + Min -8000 + Max 8000 + Fuzz 200 + Event code 1 (Y) + Value -28 + Min -8000 + Max 8000 + Fuzz 200 + Event code 2 (Z) + Value 905 + Min -8000 + Max 8000 + Fuzz 200 + Event code 40 (Misc) + Value 0 + Min 0 + Max 1 + Event type 4 (Misc) + + +Register/Platform parameters Description +---------------------------------------- + +mode: + 0: power down mode + 1: 100 Hz Measurement mode + 2: 400 Hz Measurement mode + 3: 40 Hz Measurement mode + 4: Motion Detect mode (default) + 5: 100 Hz Free fall mode + 6: 40 Hz Free fall mode + 7: Power off mode + +grange: + 2000: 2000 mg or 2G Range + 8000: 8000 mg or 8G Range + +mdthr: + X: X * 71mg (8G Range) + X: X * 18mg (2G Range) + +mdfftmr: + X: (X & 0x70) * 100 ms (MDTMR) + (X & 0x0F) * 2.5 ms (FFTMR 400 Hz) + (X & 0x0F) * 10 ms (FFTMR 100 Hz) + +ffthr: + X: (X >> 2) * 18mg (2G Range) + X: (X & 0x0F) * 71 mg (8G Range) |