summaryrefslogtreecommitdiffstats
path: root/Documentation/input/cma3000_d0x.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/input/cma3000_d0x.rst')
-rw-r--r--Documentation/input/cma3000_d0x.rst139
1 files changed, 139 insertions, 0 deletions
diff --git a/Documentation/input/cma3000_d0x.rst b/Documentation/input/cma3000_d0x.rst
new file mode 100644
index 000000000000..6f40c17c1aca
--- /dev/null
+++ b/Documentation/input/cma3000_d0x.rst
@@ -0,0 +1,139 @@
+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)