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authorHemanth V <hemanthv@ti.com>2010-11-30 23:03:54 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2010-11-30 23:05:21 -0800
commitb029ffafe89cf4b97cf39e0225a5205cbbf9e02f (patch)
tree3f5b9074c4b9b4cf35d930f057ed6a73559e1e0c /Documentation/input
parent33e808c383477e821163f133c2e3e671879c28b6 (diff)
downloadlinux-b029ffafe89cf4b97cf39e0225a5205cbbf9e02f.tar.gz
Input: add CMA3000 accelerometer driver
Add support for CMA3000 Tri-axis accelerometer, which supports Motion detect, Measurement and Free fall modes. CMA3000 supports both I2C/SPI bus for communication, currently the driver supports I2C based communication. Signed-off-by: Hemanth V <hemanthv@ti.com> Reviewed-by: Jonathan Cameron <jic23@cam.ac.uk> Reviewed-by: Sergio Aguirre <saaguirre@ti.com> Reviewed-by: Shubhrajyoti <Shubhrajyoti@ti.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
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+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)