--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AL3010 - Dyna Image Ambient Light Sensor
+ *
+ * Copyright (c) 2014, Intel Corporation.
+ * Copyright (c) 2016, Dyna-Image Corp.
+ * Copyright (c) 2020, David Heidelberg, Michał Mirosław, Dmitry Osipenko
+ *
+ * IIO driver for AL3010 (7-bit I2C slave address 0x1C).
+ *
+ * TODO: interrupt support, thresholds
+ * When the driver will get support for interrupt handling, then interrupt
+ * will need to be disabled before turning sensor OFF in order to avoid
+ * potential races with the interrupt handling.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define AL3010_DRV_NAME "al3010"
+
+#define AL3010_REG_SYSTEM 0x00
+#define AL3010_REG_DATA_LOW 0x0c
+#define AL3010_REG_CONFIG 0x10
+
+#define AL3010_CONFIG_DISABLE 0x00
+#define AL3010_CONFIG_ENABLE 0x01
+
+#define AL3010_GAIN_MASK GENMASK(6,4)
+
+#define AL3010_SCALE_AVAILABLE "1.1872 0.2968 0.0742 0.018"
+
+enum al3xxxx_range {
+ AL3XXX_RANGE_1, /* 77806 lx */
+ AL3XXX_RANGE_2, /* 19542 lx */
+ AL3XXX_RANGE_3, /* 4863 lx */
+ AL3XXX_RANGE_4 /* 1216 lx */
+};
+
+static const int al3010_scales[][2] = {
+ {0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600}
+};
+
+struct al3010_data {
+ struct i2c_client *client;
+};
+
+static const struct iio_chan_spec al3010_channels[] = {
+ {
+ .type = IIO_LIGHT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ }
+};
+
+static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE);
+
+static struct attribute *al3010_attributes[] = {
+ &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group al3010_attribute_group = {
+ .attrs = al3010_attributes,
+};
+
+static int al3010_set_pwr(struct i2c_client *client, bool pwr)
+{
+ u8 val = pwr ? AL3010_CONFIG_ENABLE : AL3010_CONFIG_DISABLE;
+ return i2c_smbus_write_byte_data(client, AL3010_REG_SYSTEM, val);
+}
+
+static void al3010_set_pwr_off(void *_data)
+{
+ struct al3010_data *data = _data;
+
+ al3010_set_pwr(data->client, false);
+}
+
+static int al3010_init(struct al3010_data *data)
+{
+ int ret;
+
+ ret = al3010_set_pwr(data->client, true);
+
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_write_byte_data(data->client, AL3010_REG_CONFIG,
+ FIELD_PREP(AL3010_GAIN_MASK,
+ AL3XXX_RANGE_3));
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int al3010_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct al3010_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ /*
+ * ALS ADC value is stored in two adjacent registers:
+ * - low byte of output is stored at AL3010_REG_DATA_LOW
+ * - high byte of output is stored at AL3010_REG_DATA_LOW + 1
+ */
+ ret = i2c_smbus_read_word_data(data->client,
+ AL3010_REG_DATA_LOW);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ ret = i2c_smbus_read_byte_data(data->client,
+ AL3010_REG_CONFIG);
+ if (ret < 0)
+ return ret;
+
+ ret = FIELD_GET(AL3010_GAIN_MASK, ret);
+ *val = al3010_scales[ret][0];
+ *val2 = al3010_scales[ret][1];
+
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+ return -EINVAL;
+}
+
+static int al3010_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long mask)
+{
+ struct al3010_data *data = iio_priv(indio_dev);
+ int i;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) {
+ if (val != al3010_scales[i][0] ||
+ val2 != al3010_scales[i][1])
+ continue;
+
+ return i2c_smbus_write_byte_data(data->client,
+ AL3010_REG_CONFIG,
+ FIELD_PREP(AL3010_GAIN_MASK, i));
+ }
+ break;
+ }
+ return -EINVAL;
+}
+
+static const struct iio_info al3010_info = {
+ .read_raw = al3010_read_raw,
+ .write_raw = al3010_write_raw,
+ .attrs = &al3010_attribute_group,
+};
+
+static int al3010_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct al3010_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &al3010_info;
+ indio_dev->name = AL3010_DRV_NAME;
+ indio_dev->channels = al3010_channels;
+ indio_dev->num_channels = ARRAY_SIZE(al3010_channels);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = al3010_init(data);
+ if (ret < 0) {
+ dev_err(&client->dev, "al3010 chip init failed\n");
+ return ret;
+ }
+
+ ret = devm_add_action_or_reset(&client->dev,
+ al3010_set_pwr_off,
+ data);
+ if (ret < 0)
+ return ret;
+
+ return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static int __maybe_unused al3010_suspend(struct device *dev)
+{
+ return al3010_set_pwr(to_i2c_client(dev), false);
+}
+
+static int __maybe_unused al3010_resume(struct device *dev)
+{
+ return al3010_set_pwr(to_i2c_client(dev), true);
+}
+
+static SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume);
+
+static const struct i2c_device_id al3010_id[] = {
+ {"al3010", },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, al3010_id);
+
+static const struct of_device_id al3010_of_match[] = {
+ { .compatible = "dynaimage,al3010", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, al3010_of_match);
+
+static struct i2c_driver al3010_driver = {
+ .driver = {
+ .name = AL3010_DRV_NAME,
+ .of_match_table = al3010_of_match,
+ .pm = &al3010_pm_ops,
+ },
+ .probe = al3010_probe,
+ .id_table = al3010_id,
+};
+module_i2c_driver(al3010_driver);
+
+MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
+MODULE_AUTHOR("David Heidelberg <david@ixit.cz>");
+MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver");
+MODULE_LICENSE("GPL v2");
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