Add support for AS7343 multi-spectral sensor

Add binding for AMS AS7343 which is a 14-channel multi-spectral sensor with i2c address of 0x39.

Datasheet: https://look.ams-osram.com/m/5f2d27fff9a874d2/original/AS7343-14-Channel-Multi-Spectral-Sensor.pdf

Signed-off-by Chang Yu <[email protected]>

---
Changes in v3:
- Add missing include for gpio.
- Expand GPIO descrption to include hardware synchronization.
- Use led-max-microamp instead of led-current-microamp for the LDR pin.

Changes in v2:
- Add the LDR, the interrupt pin, and the GPIO pin to the bindings.
- Fix node name and unit address mismatch.
- Include MAINTAINERS changes.

This patch adds a driver for the AMS AS7343 14-channel multi-spectral sensor with I2C interface.

The driver exposes 12 spectral channels (11 visible + 1 near-infrared) via the IIO sysfs interface. Each channel's raw data is provided as a 16-bit little-endian unsigned integer.

Basic power management (suspend/resume) is supported. Note that power management is designed in such a way that we only stop spectrual measurements when susepended and do not power off.

More complex features such as auto-suspend, interrupts, and configurable gain/integration time will be added in future patches.

drivers/iio/light/as7343.c new file +5 -0

+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>

drivers/iio/light/as7343.c new file +6 -0

+	switch (mask) {
+	case IIO_CHAN_INFO_RAW: {
+		/* Wait until integration time passes for all 3 cycles. */
+		msleep(160);
+
+		/*

drivers/iio/light/as7343.c new file +6 -0

+		if (ret)
+			break;
+
+		*val = le16_to_cpu(result);
+		ret = IIO_VAL_INT;
+		break;

drivers/iio/light/as7343.c new file +20 -0

+static const char *as7343_channel_label(struct iio_chan_spec const *chan)
+{
+	switch (chan->channel) {
+	case AS7343_CHAN_IDX_FZ:
+		return "FZ";
+	case AS7343_CHAN_IDX_FY:
+		return "FY";
+	case AS7343_CHAN_IDX_FXL:
+		return "FXL";
+	case AS7343_CHAN_IDX_NIR:
+		return "NIR";
+	case AS7343_CHAN_IDX_F2:
+		return "F2";
+	case AS7343_CHAN_IDX_F3:
+		return "F3";
+	case AS7343_CHAN_IDX_F4:
+		return "F4";
+	case AS7343_CHAN_IDX_F6:
+		return "F6";
+	case AS7343_CHAN_IDX_F1:

drivers/iio/light/as7343.c new file +2 -0

+	return sysfs_emit(label, "%s\n", name);
+}

+};

drivers/iio/light/as7343.c new file +13 -0

+	unsigned int val;
+	__le16 step;
+	int ret;
+
+	/* Power on */
+	ret = regmap_set_bits(data->regmap, AS7343_ENABLE, AS7343_ENABLE_PON);
+	if (ret)
+		return ret;
+
+	/* Need to set REG_BANK to 1 before we can access ID */
+	ret = regmap_set_bits(data->regmap, AS7343_CFG0, AS7343_CFG0_REG_BANK);
+	if (ret)
+		return ret;

drivers/iio/light/as7343.c new file +20 -0

+		data->regmap, AS7343_CFG20, AS7343_CFG20_AUTO_SMUX,
+		FIELD_PREP(AS7343_CFG20_AUTO_SMUX,
+			   AS7343_CFG20_AUTO_SMUX_READOUT_ALL));
+	if (ret)
+		return ret;
+
+	/* Set 50.1ms integration time and x256 gain for now */
+	step = cpu_to_le16(AS7343_ASTEP_VAL);
+	ret = regmap_bulk_write(data->regmap, AS7343_ASTEP, &step, 2);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(data->regmap, AS7343_ATIME, AS7343_ATIME_VAL);
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(data->regmap, AS7343_CFG1, AS7343_CFG1_AGAIN,
+				  FIELD_PREP(AS7343_CFG1_AGAIN,
+					     AS7343_CFG1_AGAIN_X256));
+}

drivers/iio/light/as7343.c new file +7 -0

+static int as7343_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct as7343_data *data = iio_priv(indio_dev);
+
+	return regmap_clear_bits(data->regmap, AS7343_ENABLE,
+				 AS7343_ENABLE_SP_EN);

drivers/iio/light/as7343.c new file +11 -0

+static int as7343_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct as7343_data *data;
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;

drivers/iio/light/as7343.c new file +36 -0

+
+	indio_dev->name = "as7343";
+	indio_dev->info = &as7343_info;
+	indio_dev->channels = as7343_channels;
+	indio_dev->num_channels = ARRAY_SIZE(as7343_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = devm_regulator_get_enable(dev, "vdd");
+	if (ret)
+		return ret;
+
+	ret = as7343_setup_device(dev, data);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, as7343_suspend_action, dev);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to add suspend action\n");
+
+	ret = pm_runtime_set_active(dev);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to activate PM runtime\n");
+
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable PM runtime\n");
+
+	/* Start measurements */
+	ret = regmap_set_bits(data->regmap, AS7343_ENABLE, AS7343_ENABLE_SP_EN);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}

(quoted diff) +2 -0

+};
+MODULE_DEVICE_TABLE(i2c, as7343_id);

(quoted diff) +2 -0

+};
+module_i2c_driver(as7343_driver);

On Wed, Sep 09, 2026 at 11:38:13PM -0700, Chang Yu wrote:

...

drivers/iio/light/as7343.c line 218

Quoted 10 lines

drivers/iio/light/as7343.c new file +10 -0

+}
+
+static int as7343_read_label(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan, char *label)
+{
+	const char *name;
+
+	name = as7343_channel_label(chan);
+	if (!name)
+		return -EINVAL;

Why? Can't it be taken from DT?

Quoted 2 lines

drivers/iio/light/as7343.c new file +2 -0

+	return sysfs_emit(label, "%s\n", name);
+}

...

Quoted 1 line · Andy Shevchenko

On Wed, Sep 09, 2026 at 11:38:13PM -0700, Chang Yu wrote:

Quoted 5 lines

drivers/iio/light/as7343.c line 218

Quoted 3 lines

drivers/iio/light/as7343.c new file +3 -0

+	name = as7343_channel_label(chan);
+	if (!name)
+		return -EINVAL;

Why? Can't it be taken from DT?

These channel labels correspond to the physical optical channel names defined by the datasheet. Each name corresponds to a pre-defined range of wavelengths. They are fixed internal properties of the chip, so IMO hardcoding them in the driver is more approriate.