iio: pressure: add driver and bindings for adp810

Add driver for Aosong adp810 differential pressure and temperature sensor. This sensor provides an I2C interface for reading data. Calculate CRC of the data received using standard crc8 library to verify data integrity.

+F: drivers/iio/pressure/adp810.c

# When adding new entries keep the list in alphabetical order obj-$(CONFIG_ABP060MG) += abp060mg.o

drivers/iio/pressure/Makefile +2 -0

+obj-$(CONFIG_ADP810) += adp810.o
 obj-$(CONFIG_ROHM_BM1390) += rohm-bm1390.o
 obj-$(CONFIG_BMP280) += bmp280.o
 bmp280-objs := bmp280-core.o bmp280-regmap.o

@@ -15,6 +16,7 @@ obj-$(CONFIG_DPS310) += dps310.o
 obj-$(CONFIG_IIO_CROS_EC_BARO) += cros_ec_baro.o
 obj-$(CONFIG_HID_SENSOR_PRESS)   += hid-sensor-press.o
 obj-$(CONFIG_HP03) += hp03.o
+obj-$(CONFIG_HP206C) += hp206c.o
 obj-$(CONFIG_HSC030PA) += hsc030pa.o
 obj-$(CONFIG_HSC030PA_I2C) += hsc030pa_i2c.o
 obj-$(CONFIG_HSC030PA_SPI) += hsc030pa_spi.o

@@ -34,11 +36,9 @@ obj-$(CONFIG_SDP500) += sdp500.o
 obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o
 st_pressure-y := st_pressure_core.o
 st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o

+} __packed;

drivers/iio/pressure/adp810.c new file +34 -0

+	/*
+	 * Wait for the sensor to acquire data. As per datasheet section 5.3.1,
+	 * wait for at least 10ms before reading measurements from the sensor.
+	 */
+	msleep(ADP810_MEASURE_LATENCY_MS);
+
+	/* Read sensor values */
+	ret = i2c_master_recv(client, (char *)buf, sizeof(*buf));
+	if (ret < 0) {
+		dev_err(dev, "Error reading from sensor\n");
+		return ret;
+	}
+	if (ret != sizeof(*buf))
+		return -EIO;
+
+	/* CRC checks */
+	crc8_populate_msb(crc_table, ADP810_CRC8_POLYNOMIAL);
+	if (buf->dp_crc != crc8(crc_table, (u8 *)&buf->dp, 0x2, CRC8_INIT_VALUE)) {
+		dev_err(dev, "CRC error for pressure\n");
+		return -EIO;
+	}
+
+	if (buf->tmp_crc != crc8(crc_table, (u8 *)&buf->tmp, 0x2, CRC8_INIT_VALUE)) {
+		dev_err(dev, "CRC error for temperature\n");
+		return -EIO;
+	}
+
+	if (buf->sf_crc != crc8(crc_table, (u8 *)&buf->sf, 0x2, CRC8_INIT_VALUE)) {
+		dev_err(dev, "CRC error for scale\n");
+		return -EIO;
+	}
+
+	return 0;
+}

Quoted 25 lines

# When adding new entries keep the list in alphabetical order obj-$(CONFIG_ABP060MG) += abp060mg.o

drivers/iio/pressure/Makefile +4 -1

+obj-$(CONFIG_ADP810) += adp810.o
 obj-$(CONFIG_ROHM_BM1390) += rohm-bm1390.o
 obj-$(CONFIG_BMP280) += bmp280.o
 bmp280-objs := bmp280-core.o bmp280-regmap.o

@@ -15,6 +16,7 @@ obj-$(CONFIG_DPS310) += dps310.o
 obj-$(CONFIG_IIO_CROS_EC_BARO) += cros_ec_baro.o
 obj-$(CONFIG_HID_SENSOR_PRESS)   += hid-sensor-press.o
 obj-$(CONFIG_HP03) += hp03.o
+obj-$(CONFIG_HP206C) += hp206c.o
 obj-$(CONFIG_HSC030PA) += hsc030pa.o
 obj-$(CONFIG_HSC030PA_I2C) += hsc030pa_i2c.o
 obj-$(CONFIG_HSC030PA_SPI) += hsc030pa_spi.o

@@ -34,11 +36,9 @@ obj-$(CONFIG_SDP500) += sdp500.o
 obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o
 st_pressure-y := st_pressure_core.o
 st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o
+obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o
+obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o
 obj-$(CONFIG_T5403) += t5403.o
-obj-$(CONFIG_HP206C) += hp206c.o
 obj-$(CONFIG_ZPA2326) += zpa2326.o

drivers/iio/pressure/Makefile obj-$(CONFIG_SDP500) += sdp500.o · line 44

Quoted 5 lines

drivers/iio/pressure/Makefile +0 -3

 obj-$(CONFIG_ZPA2326_I2C) += zpa2326_i2c.o
 obj-$(CONFIG_ZPA2326_SPI) += zpa2326_spi.o
-
-obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o
-obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o  

I would split order fix into a separate change, but if maintainers are okay with this approach, I would not object.

Quoted 25 lines

Quoted 25 lines

# When adding new entries keep the list in alphabetical order obj-$(CONFIG_ABP060MG) += abp060mg.o

drivers/iio/pressure/Makefile +4 -1

+obj-$(CONFIG_ADP810) += adp810.o
 obj-$(CONFIG_ROHM_BM1390) += rohm-bm1390.o
 obj-$(CONFIG_BMP280) += bmp280.o
 bmp280-objs := bmp280-core.o bmp280-regmap.o

@@ -15,6 +16,7 @@ obj-$(CONFIG_DPS310) += dps310.o
 obj-$(CONFIG_IIO_CROS_EC_BARO) += cros_ec_baro.o
 obj-$(CONFIG_HID_SENSOR_PRESS)   += hid-sensor-press.o
 obj-$(CONFIG_HP03) += hp03.o
+obj-$(CONFIG_HP206C) += hp206c.o
 obj-$(CONFIG_HSC030PA) += hsc030pa.o
 obj-$(CONFIG_HSC030PA_I2C) += hsc030pa_i2c.o
 obj-$(CONFIG_HSC030PA_SPI) += hsc030pa_spi.o

@@ -34,11 +36,9 @@ obj-$(CONFIG_SDP500) += sdp500.o
 obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o
 st_pressure-y := st_pressure_core.o
 st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o
+obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o
+obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o
 obj-$(CONFIG_T5403) += t5403.o
-obj-$(CONFIG_HP206C) += hp206c.o
 obj-$(CONFIG_ZPA2326) += zpa2326.o

Quoted 8 lines

drivers/iio/pressure/Makefile obj-$(CONFIG_SDP500) += sdp500.o · line 44

Quoted 5 lines

drivers/iio/pressure/Makefile +0 -3

 obj-$(CONFIG_ZPA2326_I2C) += zpa2326_i2c.o
 obj-$(CONFIG_ZPA2326_SPI) += zpa2326_spi.o
-
-obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o
-obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o  

I would split order fix into a separate change, but if maintainers are okay with this approach, I would not object.

I was late to replying to v2 on this. Split it out please.

Quoted 4 lines · Akhilesh Patil

Add driver for Aosong adp810 differential pressure and temperature sensor. This sensor provides an I2C interface for reading data. Calculate CRC of the data received using standard crc8 library to verify data integrity.

Thanks for an update! Looks almost good to me, some comments below.

...

MAINTAINERS S: Maintained · line 3752

Quoted 4 lines

MAINTAINERS +4 -0

+M:	Akhilesh Patil <[email protected]>
+L:	[email protected]
+S:	Maintained
+F:	Documentation/devicetree/bindings/iio/pressure/aosong,adp810.yaml

Putting it here makes checkpatch unhappy. If someone thinks that is a false positive of the tool, perhaps one needs to fix that.

Quoted 2 lines

+F: drivers/iio/pressure/adp810.c

...

Quoted 23 lines

# When adding new entries keep the list in alphabetical order obj-$(CONFIG_ABP060MG) += abp060mg.o

drivers/iio/pressure/Makefile +4 -1

+obj-$(CONFIG_ADP810) += adp810.o
 obj-$(CONFIG_ROHM_BM1390) += rohm-bm1390.o
 obj-$(CONFIG_BMP280) += bmp280.o
 bmp280-objs := bmp280-core.o bmp280-regmap.o

@@ -15,6 +16,7 @@ obj-$(CONFIG_DPS310) += dps310.o
 obj-$(CONFIG_IIO_CROS_EC_BARO) += cros_ec_baro.o
 obj-$(CONFIG_HID_SENSOR_PRESS)   += hid-sensor-press.o
 obj-$(CONFIG_HP03) += hp03.o
+obj-$(CONFIG_HP206C) += hp206c.o
 obj-$(CONFIG_HSC030PA) += hsc030pa.o
 obj-$(CONFIG_HSC030PA_I2C) += hsc030pa_i2c.o
 obj-$(CONFIG_HSC030PA_SPI) += hsc030pa_spi.o

@@ -34,11 +36,9 @@ obj-$(CONFIG_SDP500) += sdp500.o
 obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o
 st_pressure-y := st_pressure_core.o
 st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o
+obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o
+obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o
 obj-$(CONFIG_T5403) += t5403.o
-obj-$(CONFIG_HP206C) += hp206c.o
 obj-$(CONFIG_ZPA2326) += zpa2326.o

drivers/iio/pressure/Makefile obj-$(CONFIG_SDP500) += sdp500.o · line 44

Quoted 5 lines

drivers/iio/pressure/Makefile +0 -3

 obj-$(CONFIG_ZPA2326_I2C) += zpa2326_i2c.o
 obj-$(CONFIG_ZPA2326_SPI) += zpa2326_spi.o
-
-obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o
-obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o

I would split order fix into a separate change, but if maintainers are okay with this approach, I would not object.

...

drivers/iio/pressure/adp810.c line 19

Quoted 10 lines

drivers/iio/pressure/adp810.c new file +10 -0

+#include <linux/cleanup.h>
+#include <linux/crc8.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dev_printk.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/unaligned.h>

Something is still missing.

...

drivers/iio/pressure/adp810.c line 45

Quoted 7 lines

drivers/iio/pressure/adp810.c new file +7 -0

+struct adp810_read_buf {
+	__be16 dp;
+	u8 dp_crc;
+	__be16 tmp;
+	u8 tmp_crc;
+	__be16 sf;
+	u8 sf_crc;

All these types are provided in types.h

Quoted 2 lines

+} __packed;

...

drivers/iio/pressure/adp810.c line 59

Quoted 6 lines

drivers/iio/pressure/adp810.c new file +6 -0

+static int adp810_measure(struct adp810_data *data, struct adp810_read_buf *buf)
+{
+	struct i2c_client *client = data->client;
+	struct device *dev = &client->dev;
+	int ret;
+	u16 trig_cmd = ADP810_TRIGGER_COMMAND;

Shouldn't this be __be16 or __le16? Or is that really a full 16-bit command? I have a gut feeling that this should be u8 x[2] = { ... }; instead.

drivers/iio/pressure/adp810.c line 68

Quoted 9 lines

drivers/iio/pressure/adp810.c new file +8 -0

+	/* Send trigger to the sensor for measurement */
+	ret = i2c_master_send(client, (char *)&trig_cmd, sizeof(trig_cmd));
+	if (ret < 0) {
+		dev_err(dev, "Error sending trigger command\n");
+		return ret;
+	}
+	if (ret != sizeof(trig_cmd))
+		return -EIO;

-EIO is defined down from linux/errno.h.

Quoted 24 lines

drivers/iio/pressure/adp810.c new file +23 -0

+	/*
+	 * Wait for the sensor to acquire data. As per datasheet section 5.3.1,
+	 * wait for at least 10ms before reading measurements from the sensor.
+	 */
+	msleep(ADP810_MEASURE_LATENCY_MS);
+
+	/* Read sensor values */
+	ret = i2c_master_recv(client, (char *)buf, sizeof(*buf));
+	if (ret < 0) {
+		dev_err(dev, "Error reading from sensor\n");
+		return ret;
+	}
+	if (ret != sizeof(*buf))
+		return -EIO;
+
+
+	if (buf->sf_crc != crc8(crc_table, (u8 *)&buf->sf, 0x2, CRC8_INIT_VALUE)) {
+		dev_err(dev, "CRC error for scale\n");
+		return -EIO;
+	}
+
+	return 0;
+}

...

drivers/iio/pressure/adp810.c line 187

Quoted 1 line

drivers/iio/pressure/adp810.c new file +1 -0

+	indio_dev->num_channels = ARRAY_SIZE(adp810_channels);

ARRAY_SIZE() is defined in a specific header.

Signature · 3 lines

-- 
With Best Regards,
Andy Shevchenko

Add driver for Aosong adp810 differential pressure and temperature sensor. This sensor provides an I2C interface for reading data. Calculate CRC of the data received using standard crc8 library to verify data integrity.

Tested on TI am62x sk board with sensor connected at i2c-2.

Signed-off-by Akhilesh Patil <[email protected]>

+};

Quoted 5 lines · On Tue, 21 Oct 2025 11:20:30 +0530 Akhilesh Patil <[email protected]>…

Add driver for Aosong adp810 differential pressure and temperature sensor. This sensor provides an I2C interface for reading data. Calculate CRC of the data received using standard crc8 library to verify data integrity.

Quoted 3 lines

Tested on TI am62x sk board with sensor connected at i2c-2.

Signed-off-by Akhilesh Patil <[email protected]>

A couple of trivial bits of follow up from me given you are going to be doing a v4 for the stuff Andy picked up on. Otherwise I'd just have tweaked it whilst applying for these two.

Quoted 6 lines

drivers/iio/pressure/adp810.c new file +0 -0

new file mode 100644
index 000000000000..5fcb0447c628

drivers/iio/pressure/adp810.c line 28

Quoted 5 lines

drivers/iio/pressure/adp810.c new file +5 -0

+/*
+ * Time taken in ms by sensor to do measurements after triggering.
+ * As per datasheet 10ms is sufficient but we define 30ms for better margin.
+ */
+#define ADP810_MEASURE_LATENCY_MS	30

I'd just put this value in the one place that it is used and combine the two comments on why it has this particular value.

30ms seems like a bit over the top for handling silicon variation etc. Any background for the large margin? If you've seen this as necessary in practice then just state that - it's useful info to have available to a future reader of the driver.

drivers/iio/pressure/adp810.c line 151

Quoted 4 lines

drivers/iio/pressure/adp810.c new file +2 -0

+static const struct iio_info adp810_info = {
+	.read_raw	= adp810_read_raw,

Trivial but there is no benefit in using a tab before the =

In general aligning this stuff isn't a good plan. It causes a mass of churn in the long run as some of the callbacks have longer names and suddenly whole thing needs reindenting.