[PATCH v2 2/2] iio: light: add AS7343 multi-spectral sensor driver
From: Chang Yu
Date: Mon Sep 07 2026 - 17:05:46 EST
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. More complex
features such as auto-suspend, interrupts, and configurable
gain/integration time will be added in future patches.
Datasheet: https://look.ams-osram.com/m/5f2d27fff9a874d2/original/AS7343-14-Channel-Multi-Spectral-Sensor.pdf
Signed-off-by: Chang Yu <marcus.yu.56@xxxxxxxxx>
---
Changes in v2:
- Adjust the default gain to x256 and integration time to 50.1ms as
recommended by the datasheet.
- Use read_label instead of .extend
- Remove all unused scan_index related constants.
- Add missing calls to pm_runtime_* methods in probe.
- Fix various code style issues
MAINTAINERS | 1 +
drivers/iio/light/Kconfig | 11 ++
drivers/iio/light/Makefile | 1 +
drivers/iio/light/as7343.c | 372 +++++++++++++++++++++++++++++++++++++
4 files changed, 385 insertions(+)
create mode 100644 drivers/iio/light/as7343.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 8cf4e1635053..236102b3c28e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1435,6 +1435,7 @@ M: Chang Yu <marcus.yu.56@xxxxxxxxx>
L: linux-iio@xxxxxxxxxxxxxxx
S: Maintained
F: Documentation/devicetree/bindings/iio/light/ams,as7343.yaml
+F: drivers/iio/light/as7343.c
AMT (Automatic Multicast Tunneling)
M: Taehee Yoo <ap420073@xxxxxxxxx>
diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index ef36824f312f..edbeeba9d873 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -149,6 +149,17 @@ config AS73211
This driver can also be built as a module. If so, the module
will be called as73211.
+config AS7343
+ tristate "AMS AS7343 14-Channel Multi-Spectral Sensor"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ Say Y here to build support for the AMS AS7343 14-channel
+ multi-spectral sensor.
+
+ To compile this driver as a module, choose M here: the module will
+ be called as7343.
+
config BH1745
tristate "ROHM BH1745 colour sensor"
depends on I2C
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 64e354c49ed8..5d0d33802519 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_APDS9306) += apds9306.o
obj-$(CONFIG_APDS9960) += apds9960.o
obj-$(CONFIG_APDS9999) += apds9999.o
obj-$(CONFIG_AS73211) += as73211.o
+obj-$(CONFIG_AS7343) += as7343.o
obj-$(CONFIG_BH1745) += bh1745.o
obj-$(CONFIG_BH1750) += bh1750.o
obj-$(CONFIG_BH1780) += bh1780.o
diff --git a/drivers/iio/light/as7343.c b/drivers/iio/light/as7343.c
new file mode 100644
index 000000000000..f8ee0f2e7392
--- /dev/null
+++ b/drivers/iio/light/as7343.c
@@ -0,0 +1,372 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Support for AMS AS7343 14-channel multi-spectral sensor.
+ * (7-bit I2C slave address 0x39)
+ *
+ * Based on the work of:
+ * Christian Eggers <ceggers@xxxxxxx> (AS73211 driver)
+ *
+ * Copyright (c) 2026 Chang Yu <marcus.yu.56@xxxxxxxxx>
+ *
+ * Datasheets:
+ * https://look.ams-osram.com/m/5f2d27fff9a874d2/original/AS7343-14-Channel-Multi-Spectral-Sensor.pdf
+ *
+ * TODO:
+ * - Autosuspend
+ * - Support for configurable gain and integration time
+ * - Interrupt support
+ * - Add support for reading the VIS channel
+ * - Flicker detection
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sysfs.h>
+
+#include <linux/iio/iio.h>
+
+/* AS7343 registers */
+#define AS7343_ID 0x5a
+
+#define AS7343_ENABLE 0x80
+#define AS7343_ENABLE_PON BIT(0)
+#define AS7343_ENABLE_SP_EN BIT(1)
+
+/*
+ * Integration time is calculated as (ATIME + 1) * ((ASTEP + 1) * 2.78us).
+ * Setting a 30 * 1.67ms = 50.1ms integration test as the default for now.
+ */
+#define AS7343_ATIME 0x81
+#define AS7343_ATIME_VAL 29 /* (29 + 1) = 30 steps */
+#define AS7343_ASTEP 0xd4
+#define AS7343_ASTEP_VAL 599 /* 1.67ms step size */
+
+#define AS7343_CFG0 0xbf
+#define AS7343_CFG0_REG_BANK BIT(4)
+
+#define AS7343_CFG1 0xc6
+#define AS7343_CFG1_AGAIN GENMASK(4, 0)
+#define AS7343_CFG1_AGAIN_X0_5 0
+#define AS7343_CFG1_AGAIN_X1 1
+#define AS7343_CFG1_AGAIN_X2 2
+#define AS7343_CFG1_AGAIN_X4 3
+#define AS7343_CFG1_AGAIN_X8 4
+#define AS7343_CFG1_AGAIN_X16 5
+#define AS7343_CFG1_AGAIN_X32 6
+#define AS7343_CFG1_AGAIN_X64 7
+#define AS7343_CFG1_AGAIN_X128 8
+#define AS7343_CFG1_AGAIN_X256 9
+#define AS7343_CFG1_AGAIN_X512 10
+#define AS7343_CFG1_AGAIN_X1024 11
+#define AS7343_CFG1_AGAIN_X2048 12
+
+#define AS7343_CFG20 0xd6
+#define AS7343_CFG20_AUTO_SMUX GENMASK(6, 5)
+#define AS7343_CFG20_AUTO_SMUX_READOUT_ALL 3 /* all-channel readout */
+
+#define AS7343_ASTATUS 0x94
+
+/* AS7343 data registers */
+#define AS7343_DATA_FZ 0x95
+#define AS7343_DATA_FY 0x97
+#define AS7343_DATA_FXL 0x99
+#define AS7343_DATA_NIR 0x9b
+#define AS7343_DATA_F2 0xa1
+#define AS7343_DATA_F3 0xa3
+#define AS7343_DATA_F4 0xa5
+#define AS7343_DATA_F6 0xa7
+#define AS7343_DATA_F1 0xad
+#define AS7343_DATA_F7 0xaf
+#define AS7343_DATA_F8 0xb1
+#define AS7343_DATA_F5 0xb3
+#define AS7343_MAX 0xff
+
+/* AS7343 channel indices. MUST match data register order above. */
+#define AS7343_CHAN_IDX_FZ 0
+#define AS7343_CHAN_IDX_FY 1
+#define AS7343_CHAN_IDX_FXL 2
+#define AS7343_CHAN_IDX_NIR 3
+#define AS7343_CHAN_IDX_F2 4
+#define AS7343_CHAN_IDX_F3 5
+#define AS7343_CHAN_IDX_F4 6
+#define AS7343_CHAN_IDX_F6 7
+#define AS7343_CHAN_IDX_F1 8
+#define AS7343_CHAN_IDX_F7 9
+#define AS7343_CHAN_IDX_F8 10
+#define AS7343_CHAN_IDX_F5 11
+
+#define AS7343_CHAN(_chan) \
+ { \
+ .type = IIO_INTENSITY, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .address = AS7343_DATA_##_chan, \
+ .indexed = 1, \
+ .channel = AS7343_CHAN_IDX_##_chan, \
+ }
+
+static const struct iio_chan_spec as7343_channels[] = {
+ AS7343_CHAN(FZ), AS7343_CHAN(FY), AS7343_CHAN(FXL), AS7343_CHAN(NIR),
+ AS7343_CHAN(F2), AS7343_CHAN(F3), AS7343_CHAN(F4), AS7343_CHAN(F6),
+ AS7343_CHAN(F1), AS7343_CHAN(F7), AS7343_CHAN(F8), AS7343_CHAN(F5),
+};
+
+struct as7343_data {
+ struct regmap *regmap;
+};
+
+static int as7343_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct as7343_data *data = iio_priv(indio_dev);
+ int ret;
+ unsigned int unused;
+ u16 result;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW: {
+ /*
+ * Reading ASTATUS latches all data registers to this read.
+ * We don't care about the returned saturation/gain status for
+ * now.
+ */
+ ret = regmap_read(data->regmap, AS7343_ASTATUS, &unused);
+ if (ret)
+ return ret;
+
+ ret = regmap_bulk_read(data->regmap, chan->address, &result, 2);
+ if (ret)
+ return ret;
+
+ *val = le16_to_cpu(result);
+ return IIO_VAL_INT;
+ }
+
+ default:
+ return -EINVAL;
+ }
+}
+
+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:
+ return "F1";
+ case AS7343_CHAN_IDX_F7:
+ return "F7";
+ case AS7343_CHAN_IDX_F8:
+ return "F8";
+ case AS7343_CHAN_IDX_F5:
+ return "F5";
+ default:
+ return NULL;
+ }
+}
+
+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;
+ return sysfs_emit(label, "%s\n", name);
+}
+
+static const struct iio_info as7343_info = {
+ .read_raw = as7343_read_raw,
+ .read_label = as7343_read_label,
+};
+
+static const struct regmap_config as7343_regmap_config = {
+ .name = "as7343",
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = AS7343_MAX,
+ .reg_format_endian = REGMAP_ENDIAN_LITTLE,
+ .val_format_endian = REGMAP_ENDIAN_LITTLE,
+ .cache_type = REGCACHE_NONE,
+};
+
+static int as7343_setup_device(struct device *dev, struct as7343_data *data)
+{
+ unsigned int val;
+ u16 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;
+
+ ret = regmap_read(data->regmap, AS7343_ID, &val);
+ if (val != 0x81)
+ dev_info(dev, "Unknown device ID: %x\n", val);
+
+ ret = regmap_clear_bits(data->regmap, AS7343_CFG0,
+ AS7343_CFG0_REG_BANK);
+ if (ret)
+ return ret;
+
+ /* Configure the SMUX to readout all channels */
+ ret = regmap_update_bits(
+ 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;
+
+ ret = regmap_update_bits(data->regmap, AS7343_CFG1, AS7343_CFG1_AGAIN,
+ FIELD_PREP(AS7343_CFG1_AGAIN,
+ AS7343_CFG1_AGAIN_X256));
+ if (ret)
+ return ret;
+
+ /* Start measurements */
+ return regmap_set_bits(data->regmap, AS7343_ENABLE,
+ AS7343_ENABLE_SP_EN);
+}
+
+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);
+}
+
+static int as7343_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct as7343_data *data = iio_priv(indio_dev);
+
+ return regmap_set_bits(data->regmap, AS7343_ENABLE,
+ AS7343_ENABLE_SP_EN);
+}
+
+static void as7343_suspend_action(void *data)
+{
+ as7343_suspend(data);
+}
+
+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;
+
+ regmap = devm_regmap_init_i2c(client, &as7343_regmap_config);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->regmap = regmap;
+
+ 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(&client->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");
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(as7343_pm_ops, as7343_suspend, as7343_resume,
+ NULL);
+
+static const struct of_device_id as7343_of_match[] = {
+ { .compatible = "ams,as7343" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, as7343_of_match);
+
+static const struct i2c_device_id as7343_id[] = {
+ { .name = "as7343" },
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, as7343_id);
+
+static struct i2c_driver as7343_driver = {
+ .driver = {
+ .name = "as7343",
+ .of_match_table = as7343_of_match,
+ .pm = pm_sleep_ptr(&as7343_pm_ops),
+ },
+ .probe = as7343_probe,
+ .id_table = as7343_id,
+};
+module_i2c_driver(as7343_driver);
+
+MODULE_AUTHOR("Chang Yu <marcus.yu.56@xxxxxxxxx>");
+MODULE_DESCRIPTION("AS7343 14 Channel Multi-Spectral Sensor driver");
+MODULE_LICENSE("GPL");
--
2.55.0