dt-bindings: vendor-prefixes: add aosong

Aosong Electronic Co., LTD. is a supplier for MEMS sensors such as AHT20 temperature and humidity sensor under the brand name Asair

---

Changes for v5,4,3:
- no updates

Changes for v2:
- Changed vendor prefix from asair to aosong

Previous versions:
v4: https://lore.kernel.org/lkml/[email protected]/
v3: https://lore.kernel.org/lkml/[email protected]/
v2: https://lore.kernel.org/lkml/[email protected]/
v1: https://lore.kernel.org/lkml/[email protected]/

---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

index 573578db9509..48d4ff635562 100644
@@ -117,6 +117,8 @@ patternProperties:
     description: Andes Technology Corporation
   "^anvo,.*":
     description: Anvo-Systems Dresden GmbH
+  "^aosong,.*":
+    description: Guangzhou Aosong Electronic Co., Ltd.
   "^apm,.*":
     description: Applied Micro Circuits Corporation (APM)
   "^apple,.*":

2.43.0

Add bindings for Aosong AGS02MA TVOC sensor.

The sensor communicates over i2c with the default address 0x1a. TVOC values can be read in the units of ppb and ug/m^3 at register 0x00.

Datasheet: https://asairsensors.com/wp-content/uploads/2021/09/AGS02MA.pdf

---

Changes for v5:
- Made vdd-supply a required property

Changes for v4:
- Changed node name from 'light-sensor' to 'voc-sensor'

Changes for v3:
- Fixed commit message
- Removed "asair,ags02ma" compatible

Changes for v2:
- Removed device from trivial-devices
- Added standalone binding with vdd-supply property

Previous versions:
v4: https://lore.kernel.org/lkml/[email protected]/
v3: https://lore.kernel.org/lkml/[email protected]/
v2: https://lore.kernel.org/lkml/[email protected]/
v1: https://lore.kernel.org/lkml/[email protected]/

---
 .../bindings/iio/chemical/aosong,ags02ma.yaml | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/chemical/aosong,ags02ma.yaml

new file mode 100644
index 000000000000..35e7b094e878
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/chemical/aosong,ags02ma.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Aosong AGS02MA VOC Sensor
+
+description: |
+  AGS02MA is an TVOC (Total Volatile Organic Compounds) i2c sensor with default
+  address of 0x1a.
+
+  Datasheet:
+    https://asairsensors.com/wp-content/uploads/2021/09/AGS02MA.pdf
+
+maintainers:
+  - Anshul Dalal <[email protected]>
+
+properties:
+  compatible:
+    enum:
+      - aosong,ags02ma
+
+  reg:
+    maxItems: 1
+
+  vdd-supply: true
+
+required:
+  - compatible
+  - reg
+  - vdd-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        voc-sensor@1a {
+            compatible = "aosong,ags02ma";
+            reg = <0x1a>;
+            vdd-supply = <&vdd_regulator>;
+        };
+    };

2.43.0

A simple driver for the TVOC (Total Volatile Organic Compounds) sensor from Aosong: AGS02MA

Steps in reading the VOC sensor value over i2c:
1. Read 5 bytes from the register AGS02MA_TVOC_READ_REG [0x00]
2. The first 4 bytes are taken as the big endian sensor data with final byte being the CRC
3. The CRC is verified and the value is returned over an IIO_CHAN_INFO_RAW channel as percents

Tested on Raspberry Pi Zero 2W

Datasheet: https://asairsensors.com/wp-content/uploads/2021/09/AGS02MA.pdf

---

Changes for v5:
- Removed AGS02MA_DEVICE_NAME define
- Saperated return value from data in ags02ma_register_read
- Added IIO_CHAN_INFO_SCALE for ppb to percent conversion
- Changed ags02ma_channels (iio_chan_spec[1]) to ags02ma_channel (iio_chan_spec) since only driver only uses a single channel
- Use dev_err_probe instead of dev_err
- removed unnecessary i2c_set_clientdata(..)
- Removed of_match_ptr(..)

Changes for v4:
- Fixed warning: unused variable 'ags02ma_of_table'
- Fixed warning: unsigned 'ret' is never less than zero in ags02ma_register_read

Changes for v3:
- Added of_device_id

Changes for v2:
- Fixed Kconfig not selecting CRC8 (used to be select crc8)
- Changed instances of asair to aosong
- Report raw readings in percents instead of ppb
- Added myself as maintainer for the device binding

Previous versions:
v4: https://lore.kernel.org/lkml/[email protected]/
v3: https://lore.kernel.org/lkml/[email protected]/
v2: https://lore.kernel.org/lkml/[email protected]/
v1: https://lore.kernel.org/lkml/[email protected]/

---
 MAINTAINERS                    |   7 ++
 drivers/iio/chemical/Kconfig   |  11 +++
 drivers/iio/chemical/Makefile  |   1 +
 drivers/iio/chemical/ags02ma.c | 164 +++++++++++++++++++++++++++++++++
 4 files changed, 183 insertions(+)
 create mode 100644 drivers/iio/chemical/ags02ma.c

index 81d5fc0bba68..ba3c950aca1b 100644
@@ -3028,6 +3028,13 @@ S:	Supported
 W:	http://www.akm.com/
 F:	drivers/iio/magnetometer/ak8974.c
 
+AOSONG AGS02MA TVOC SENSOR DRIVER
+M:	Anshul Dalal <[email protected]>
+L:	[email protected]
+S:	Maintained
+F:	Documentation/devicetree/bindings/iio/chemical/aosong,ags02ma.yaml
+F:	drivers/iio/chemical/ags02ma.c
+
 ASC7621 HARDWARE MONITOR DRIVER
 M:	George Joseph <[email protected]>
 L:	[email protected]

index c30657e10ee1..02649ab81b3c 100644
@@ -5,6 +5,17 @@
 
 menu "Chemical Sensors"
 
+config AOSONG_AGS02MA
+	tristate "Aosong AGS02MA TVOC sensor driver"
+	depends on I2C
+	select CRC8
+	help
+	  Say Y here to build support for Aosong AGS02MA TVOC (Total Volatile
+	  Organic Compounds) sensor.
+
+	  To compile this driver as module, choose M here: the module will be
+	  called ags02ma.
+
 config ATLAS_PH_SENSOR
 	tristate "Atlas Scientific OEM SM sensors"
 	depends on I2C

index a11e777a7a00..2f3dee8bb779 100644
@@ -4,6 +4,7 @@
 #
 
 # When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AOSONG_AGS02MA)	+= ags02ma.o
 obj-$(CONFIG_ATLAS_PH_SENSOR)	+= atlas-sensor.o
 obj-$(CONFIG_ATLAS_EZO_SENSOR)	+= atlas-ezo-sensor.o
 obj-$(CONFIG_BME680) += bme680_core.o

2.43.0

Hi Anshul, Just one trivial thing. I'll fix up whilst applying.

Applied to the togreg branch of iio.git. Will be initially pushed out as testing for 0-day to see if it can find anything we missed.

Thanks,

Jonathan