[mirror_ubuntu-zesty-kernel.git] / Documentation / hwmon / ads1015

Kernel driver ads1015
=====================

Supported chips:
  * Texas Instruments ADS1015
    Prefix: 'ads1015'
    Datasheet: Publicly available at the Texas Instruments website :
               http://focus.ti.com/lit/ds/symlink/ads1015.pdf
  * Texas Instruments ADS1115
    Prefix: 'ads1115'
    Datasheet: Publicly available at the Texas Instruments website :
               http://focus.ti.com/lit/ds/symlink/ads1115.pdf

Authors:
        Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>

Description
-----------

This driver implements support for the Texas Instruments ADS1015/ADS1115.

This device is a 12/16-bit A-D converter with 4 inputs.

The inputs can be used single ended or in certain differential combinations.

The inputs can be made available by 8 sysfs input files in0_input - in7_input:
in0: Voltage over AIN0 and AIN1.
in1: Voltage over AIN0 and AIN3.
in2: Voltage over AIN1 and AIN3.
in3: Voltage over AIN2 and AIN3.
in4: Voltage over AIN0 and GND.
in5: Voltage over AIN1 and GND.
in6: Voltage over AIN2 and GND.
in7: Voltage over AIN3 and GND.

Which inputs are available can be configured using platform data or devicetree.

By default all inputs are exported.

Platform Data
-------------

In linux/i2c/ads1015.h platform data is defined, channel_data contains
configuration data for the used input combinations:
- pga is the programmable gain amplifier (values are full scale)
  0: +/- 6.144 V
  1: +/- 4.096 V
  2: +/- 2.048 V
  3: +/- 1.024 V
  4: +/- 0.512 V
  5: +/- 0.256 V
- data_rate in samples per second
  0: 128
  1: 250
  2: 490
  3: 920
  4: 1600
  5: 2400
  6: 3300

Example:
struct ads1015_platform_data data = {
	.channel_data = {
		[2] = { .enabled = true, .pga = 1, .data_rate = 0 },
		[4] = { .enabled = true, .pga = 4, .data_rate = 5 },
	}
};

In this case only in2_input (FS +/- 4.096 V, 128 SPS) and in4_input
(FS +/- 0.512 V, 2400 SPS) would be created.

Devicetree
----------

Configuration is also possible via devicetree:
Documentation/devicetree/bindings/hwmon/ads1015.txt
Commit	Line	Data
8c22a8f5 DE	1	Kernel driver ads1015
	2	=====================
	3
	4	Supported chips:
	5	* Texas Instruments ADS1015
	6	Prefix: 'ads1015'
	7	Datasheet: Publicly available at the Texas Instruments website :
	8	http://focus.ti.com/lit/ds/symlink/ads1015.pdf
60c1f31f ED	9	* Texas Instruments ADS1115
	10	Prefix: 'ads1115'
	11	Datasheet: Publicly available at the Texas Instruments website :
	12	http://focus.ti.com/lit/ds/symlink/ads1115.pdf
8c22a8f5 DE	13
	14	Authors:
	15	Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>
	16
	17	Description
	18	-----------
	19
60c1f31f	20	This driver implements support for the Texas Instruments ADS1015/ADS1115.
8c22a8f5	21
60c1f31f	22	This device is a 12/16-bit A-D converter with 4 inputs.
8c22a8f5 DE	23
	24	The inputs can be used single ended or in certain differential combinations.
	25
c0046867	26	The inputs can be made available by 8 sysfs input files in0_input - in7_input:
8c22a8f5 DE	27	in0: Voltage over AIN0 and AIN1.
	28	in1: Voltage over AIN0 and AIN3.
	29	in2: Voltage over AIN1 and AIN3.
	30	in3: Voltage over AIN2 and AIN3.
	31	in4: Voltage over AIN0 and GND.
	32	in5: Voltage over AIN1 and GND.
	33	in6: Voltage over AIN2 and GND.
	34	in7: Voltage over AIN3 and GND.
	35
c0046867	36	Which inputs are available can be configured using platform data or devicetree.
8c22a8f5 DE	37
	38	By default all inputs are exported.
	39
	40	Platform Data
	41	-------------
	42
c0046867 DE	43	In linux/i2c/ads1015.h platform data is defined, channel_data contains
	44	configuration data for the used input combinations:
	45	- pga is the programmable gain amplifier (values are full scale)
	46	0: +/- 6.144 V
	47	1: +/- 4.096 V
	48	2: +/- 2.048 V
	49	3: +/- 1.024 V
	50	4: +/- 0.512 V
	51	5: +/- 0.256 V
	52	- data_rate in samples per second
	53	0: 128
	54	1: 250
	55	2: 490
	56	3: 920
	57	4: 1600
	58	5: 2400
	59	6: 3300
8c22a8f5 DE	60
	61	Example:
	62	struct ads1015_platform_data data = {
c0046867 DE	63	.channel_data = {
	64	[2] = { .enabled = true, .pga = 1, .data_rate = 0 },
	65	[4] = { .enabled = true, .pga = 4, .data_rate = 5 },
	66	}
8c22a8f5 DE	67	};
8c22a8f5 DE	68
c0046867 DE	69	In this case only in2_input (FS +/- 4.096 V, 128 SPS) and in4_input
c0046867 DE	70	(FS +/- 0.512 V, 2400 SPS) would be created.
8c22a8f5 DE	71
	72	Devicetree
	73	----------
	74
c0046867 DE	75	Configuration is also possible via devicetree:
c0046867 DE	76	Documentation/devicetree/bindings/hwmon/ads1015.txt