[PATCH v3 1/3] dt-bindings: vendor-prefixes: add aosong

[PATCH v3 1/3] dt-bindings: vendor-prefixes: add aosong

[Anshul Dalal]

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

Signed-off-by: Anshul Dalal <anshulusr@gmail.com>
---

Changes for v3:
- no updates

v2: https://lore.kernel.org/lkml/20231115125810.1394854-1-anshulusr@gmail.com/

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

v1: https://lore.kernel.org/lkml/20231107173100.62715-1-anshulusr@gmail.com/
---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index 573578db9509..48d4ff635562 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -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,.*":
-- 
2.42.1

[PATCH v3 2/3] dt-bindings: iio: chemical: add aosong,ags02ma

[Anshul Dalal]

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
Product-Page:
  http://www.aosong.com/m/en/products-33.html

Signed-off-by: Anshul Dalal <anshulusr@gmail.com>
---

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

v2: https://lore.kernel.org/lkml/20231115125810.1394854-2-anshulusr@gmail.com/

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

v1: https://lore.kernel.org/lkml/20231107173100.62715-2-anshulusr@gmail.com/
---
 .../bindings/iio/chemical/aosong,ags02ma.yaml | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/chemical/aosong,ags02ma.yaml

diff --git a/Documentation/devicetree/bindings/iio/chemical/aosong,ags02ma.yaml b/Documentation/devicetree/bindings/iio/chemical/aosong,ags02ma.yaml
new file mode 100644
index 000000000000..38ba3614ae8a
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/chemical/aosong,ags02ma.yaml
@@ -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 <anshulusr@gmail.com>
+
+properties:
+  compatible:
+    enum:
+      - aosong,ags02ma
+
+  reg:
+    maxItems: 1
+
+  vdd-supply: true
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        light-sensor@1a {
+            compatible = "aosong,ags02ma";
+            reg = <0x1a>;
+            vdd-supply = <&vdd_regulator>;
+        };
+    };
-- 
2.42.1

[PATCH v3 3/3] iio: chemical: add support for Aosong AGS02MA

[Anshul Dalal]

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
Product-Page:
  http://www.aosong.com/m/en/products-33.html

Signed-off-by: Anshul Dalal <anshulusr@gmail.com>
---

Changes for v3:
- Added of_device_id

v2: https://lore.kernel.org/lkml/20231115125810.1394854-3-anshulusr@gmail.com/

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

v1: https://lore.kernel.org/lkml/20231107173100.62715-3-anshulusr@gmail.com/
---
 MAINTAINERS                    |   7 ++
 drivers/iio/chemical/Kconfig   |  11 +++
 drivers/iio/chemical/Makefile  |   1 +
 drivers/iio/chemical/ags02ma.c | 168 +++++++++++++++++++++++++++++++++
 4 files changed, 187 insertions(+)
 create mode 100644 drivers/iio/chemical/ags02ma.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 81d5fc0bba68..ba3c950aca1b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -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 <anshulusr@gmail.com>
+L:	linux-iio@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/iio/chemical/aosong,ags02ma.yaml
+F:	drivers/iio/chemical/ags02ma.c
+
 ASC7621 HARDWARE MONITOR DRIVER
 M:	George Joseph <george.joseph@fairview5.com>
 L:	linux-hwmon@vger.kernel.org
diff --git a/drivers/iio/chemical/Kconfig b/drivers/iio/chemical/Kconfig
index c30657e10ee1..02649ab81b3c 100644
--- a/drivers/iio/chemical/Kconfig
+++ b/drivers/iio/chemical/Kconfig
@@ -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
diff --git a/drivers/iio/chemical/Makefile b/drivers/iio/chemical/Makefile
index a11e777a7a00..2f3dee8bb779 100644
--- a/drivers/iio/chemical/Makefile
+++ b/drivers/iio/chemical/Makefile
@@ -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
diff --git a/drivers/iio/chemical/ags02ma.c b/drivers/iio/chemical/ags02ma.c
new file mode 100644
index 000000000000..04a07307caa9
--- /dev/null
+++ b/drivers/iio/chemical/ags02ma.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2023 Anshul Dalal <anshulusr@gmail.com>
+ *
+ * Driver for Aosong AGS02MA
+ *
+ * Datasheet:
+ *   https://asairsensors.com/wp-content/uploads/2021/09/AGS02MA.pdf
+ * Product Page:
+ *   http://www.aosong.com/m/en/products-33.html
+ *
+ * TODO:
+ *   - Add support for ug/m^3 units of measurement
+ *   - Add support for modifying i2c address
+ */
+
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+
+#define AGS02MA_DEVICE_NAME		   "ags02ma"
+
+#define AGS02MA_TVOC_READ_REG		   0x00
+#define AGS02MA_VERSION_REG		   0x11
+
+#define AGS02MA_VERSION_PROCESSING_DELAY   30
+#define AGS02MA_TVOC_READ_PROCESSING_DELAY 1500
+
+#define AGS02MA_CRC8_INIT		   0xff
+#define AGS02MA_CRC8_POLYNOMIAL		   0x31
+#define AGS02MA_PPB_PERCENT_CONVERSION     10000000
+
+DECLARE_CRC8_TABLE(ags02ma_crc8_table);
+
+struct ags02ma_data {
+	struct i2c_client *client;
+};
+
+struct ags02ma_reading {
+	__be32 data;
+	u8 crc;
+} __packed;
+
+static u32 ags02ma_register_read(struct i2c_client *client, u8 reg, u16 delay)
+{
+	u32 ret;
+	u8 crc;
+	struct ags02ma_reading read_buffer;
+
+	ret = i2c_master_send(client, &reg, sizeof(reg));
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"Failed to send data to register 0x%x: %d", reg, ret);
+		return ret;
+	}
+
+	/* Processing Delay, Check Table 7.7 in the datasheet */
+	msleep_interruptible(delay);
+
+	ret = i2c_master_recv(client, (u8 *)&read_buffer, sizeof(read_buffer));
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"Failed to receive from register 0x%x: %d", reg, ret);
+		return ret;
+	}
+	ret = be32_to_cpu(read_buffer.data);
+
+	crc = crc8(ags02ma_crc8_table, (u8 *)&read_buffer.data,
+		   sizeof(read_buffer.data), AGS02MA_CRC8_INIT);
+	if (crc != read_buffer.crc) {
+		dev_err(&client->dev, "CRC error\n");
+		return -EIO;
+	}
+
+	return ret;
+}
+
+static int ags02ma_read_raw(struct iio_dev *iio_device,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long mask)
+{
+	int ret;
+	struct ags02ma_data *data = iio_priv(iio_device);
+
+	if (mask == IIO_CHAN_INFO_RAW) {
+		/* The sensor reads data as ppb */
+		ret = ags02ma_register_read(data->client, AGS02MA_TVOC_READ_REG,
+					    AGS02MA_TVOC_READ_PROCESSING_DELAY);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		*val2 = AGS02MA_PPB_PERCENT_CONVERSION;
+		return IIO_VAL_FRACTIONAL;
+	} else {
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info ags02ma_info = {
+	.read_raw = ags02ma_read_raw,
+};
+
+static const struct iio_chan_spec ags02ma_channels[] = {
+	{ .type = IIO_CONCENTRATION,
+	  .channel2 = IIO_MOD_VOC,
+	  .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) }
+};
+
+static int ags02ma_probe(struct i2c_client *client)
+{
+	int ret;
+	struct ags02ma_data *data;
+	struct iio_dev *indio_dev;
+	u32 version;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	crc8_populate_msb(ags02ma_crc8_table, AGS02MA_CRC8_POLYNOMIAL);
+
+	ret = ags02ma_register_read(client, AGS02MA_VERSION_REG,
+				    AGS02MA_VERSION_PROCESSING_DELAY);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed to read device version: %d", ret);
+		return ret;
+	}
+	version = ret;
+	dev_dbg(&client->dev, "Aosong AGS02MA, Version: 0x%x", version);
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	indio_dev->info = &ags02ma_info;
+	indio_dev->channels = ags02ma_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ags02ma_channels);
+	indio_dev->name = AGS02MA_DEVICE_NAME;
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id ags02ma_id_table[] = {
+	{ AGS02MA_DEVICE_NAME, 0 },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, ags02ma_id_table);
+
+static const struct of_device_id ags02ma_of_table[] = {
+	{ .compatible = "aosong,ags02ma"},
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ags02ma_of_table);
+
+static struct i2c_driver ags02ma_driver = {
+	.driver = {
+		.name = AGS02MA_DEVICE_NAME,
+		.of_match_table = of_match_ptr(ags02ma_of_table),
+	},
+	.id_table = ags02ma_id_table,
+	.probe = ags02ma_probe,
+};
+module_i2c_driver(ags02ma_driver);
+
+MODULE_AUTHOR("Anshul Dalal <anshulusr@gmail.com>");
+MODULE_DESCRIPTION("Aosong AGS02MA TVOC Driver");
+MODULE_LICENSE("GPL");
-- 
2.42.1

Re: [PATCH v3 1/3] dt-bindings: vendor-prefixes: add aosong

[Krzysztof Kozlowski]

On 21/11/2023 10:57, Anshul Dalal wrote:
> Aosong Electronic Co., LTD. is a supplier for MEMS sensors such as AHT20
> temperature and humidity sensor under the brand name Asair
> 
> Signed-off-by: Anshul Dalal <anshulusr@gmail.com>
> ---
> 


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH v3 2/3] dt-bindings: iio: chemical: add aosong,ags02ma

[Krzysztof Kozlowski]

On 21/11/2023 10:57, Anshul Dalal wrote:
> 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
> Product-Page:
>   http://www.aosong.com/m/en/products-33.html
> 


> +---
> +$id: http://devicetree.org/schemas/iio/chemical/aosong,ags02ma.yaml#
> +$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.

What does it measure? Light?

> +
> +  Datasheet:
> +    https://asairsensors.com/wp-content/uploads/2021/09/AGS02MA.pdf
> +
> +maintainers:
> +  - Anshul Dalal <anshulusr@gmail.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - aosong,ags02ma
> +
> +  reg:
> +    maxItems: 1
> +
> +  vdd-supply: true
> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        light-sensor@1a {


You called it chemical, so why this is here light-sensor?

> +            compatible = "aosong,ags02ma";
> +            reg = <0x1a>;
> +            vdd-supply = <&vdd_regulator>;
> +        };
> +    };

Best regards,
Krzysztof

Re: [PATCH v3 2/3] dt-bindings: iio: chemical: add aosong,ags02ma

[Anshul Dalal]

On 11/21/23 15:33, Krzysztof Kozlowski wrote:
> On 21/11/2023 10:57, Anshul Dalal wrote:
>> 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
>> Product-Page:
>>   http://www.aosong.com/m/en/products-33.html
>>
> 
> 
>> +---
>> +$id: http://devicetree.org/schemas/iio/chemical/aosong,ags02ma.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Aosong AGS02MA VOC Sensor
>> [..]
>> +examples:
>> +  - |
>> +    #include <dt-bindings/interrupt-controller/irq.h>
>> +    i2c {
>> +        #address-cells = <1>;
>> +        #size-cells = <0>;
>> +
>> +        light-sensor@1a {
> 
> 
> You called it chemical, so why this is here light-sensor?

I was working on a binding for a light sensor in parallel at that time,
I probably forgot to change this when copying the example from the light
sensor.

Would be replaced by "voc-sensor" in the next revision, apologies for
any inconvenience.

Thanks for the review.

Best Regards,
Anshul

Re: [PATCH v3 3/3] iio: chemical: add support for Aosong AGS02MA

[kernel test robot]

Hi Anshul,

kernel test robot noticed the following build warnings:

[auto build test WARNING on jic23-iio/togreg]
[also build test WARNING on linus/master v6.7-rc2 next-20231124]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Anshul-Dalal/dt-bindings-iio-chemical-add-aosong-ags02ma/20231121-180435
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
patch link:    https://lore.kernel.org/r/20231121095800.2180870-3-anshulusr%40gmail.com
patch subject: [PATCH v3 3/3] iio: chemical: add support for Aosong AGS02MA
config: s390-randconfig-r081-20231123 (https://download.01.org/0day-ci/archive/20231124/202311241129.HrMrED0B-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231124/202311241129.HrMrED0B-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311241129.HrMrED0B-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/iio/chemical/ags02ma.c:150:34: warning: unused variable 'ags02ma_of_table' [-Wunused-const-variable]
     150 | static const struct of_device_id ags02ma_of_table[] = {
         |                                  ^
   1 warning generated.


vim +/ags02ma_of_table +150 drivers/iio/chemical/ags02ma.c

   149	
 > 150	static const struct of_device_id ags02ma_of_table[] = {
   151		{ .compatible = "aosong,ags02ma"},
   152		{ /* Sentinel */ }
   153	};
   154	MODULE_DEVICE_TABLE(of, ags02ma_of_table);
   155	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v3 3/3] iio: chemical: add support for Aosong AGS02MA

[kernel test robot]

Hi Anshul,

kernel test robot noticed the following build warnings:

[auto build test WARNING on jic23-iio/togreg]
[also build test WARNING on linus/master v6.7-rc2 next-20231124]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Anshul-Dalal/dt-bindings-iio-chemical-add-aosong-ags02ma/20231121-180435
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
patch link:    https://lore.kernel.org/r/20231121095800.2180870-3-anshulusr%40gmail.com
patch subject: [PATCH v3 3/3] iio: chemical: add support for Aosong AGS02MA
config: arm-randconfig-r081-20231123 (https://download.01.org/0day-ci/archive/20231125/202311251636.m0yt3fIb-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 13.2.0
reproduce: (https://download.01.org/0day-ci/archive/20231125/202311251636.m0yt3fIb-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311251636.m0yt3fIb-lkp@intel.com/

New smatch warnings:
drivers/iio/chemical/ags02ma.c:53 ags02ma_register_read() warn: unsigned 'ret' is never less than zero.

Old smatch warnings:
drivers/iio/chemical/ags02ma.c:63 ags02ma_register_read() warn: unsigned 'ret' is never less than zero.

vim +/ret +53 drivers/iio/chemical/ags02ma.c

    45	
    46	static u32 ags02ma_register_read(struct i2c_client *client, u8 reg, u16 delay)
    47	{
    48		u32 ret;
    49		u8 crc;
    50		struct ags02ma_reading read_buffer;
    51	
    52		ret = i2c_master_send(client, &reg, sizeof(reg));
  > 53		if (ret < 0) {
    54			dev_err(&client->dev,
    55				"Failed to send data to register 0x%x: %d", reg, ret);
    56			return ret;
    57		}
    58	
    59		/* Processing Delay, Check Table 7.7 in the datasheet */
    60		msleep_interruptible(delay);
    61	
    62		ret = i2c_master_recv(client, (u8 *)&read_buffer, sizeof(read_buffer));
    63		if (ret < 0) {
    64			dev_err(&client->dev,
    65				"Failed to receive from register 0x%x: %d", reg, ret);
    66			return ret;
    67		}
    68		ret = be32_to_cpu(read_buffer.data);
    69	
    70		crc = crc8(ags02ma_crc8_table, (u8 *)&read_buffer.data,
    71			   sizeof(read_buffer.data), AGS02MA_CRC8_INIT);
    72		if (crc != read_buffer.crc) {
    73			dev_err(&client->dev, "CRC error\n");
    74			return -EIO;
    75		}
    76	
    77		return ret;
    78	}
    79	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki