iio: light: Add support for AL3000a illuminance sensor

AL3000a is a simple I2C-based ambient light sensor, which is
closely related to AL3010 and AL3320a, but has significantly
different way of processing data generated by the sensor.

Tested-by: Robert Eckelmann <longnoserob@gmail.com>
Tested-by: Antoni Aloy Torrens <aaloytorrens@gmail.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: David Heidelberg <david@ixit.cz>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20250217140336.107476-3-clamor95@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/Kconfig

@@ -43,6 +43,16 @@ config ADUX1020
 	 To compile this driver as a module, choose M here: the
 	 module will be called adux1020.
 
+config AL3000A
+	tristate "AL3000a ambient light sensor"
+	depends on I2C
+	help
+	  Say Y here if you want to build a driver for the Dyna Image AL3000a
+	  ambient light sensor.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called al3000a.
+
 config AL3010
 	tristate "AL3010 ambient light sensor"
 	depends on I2C

drivers/iio/light/Makefile

@@ -7,6 +7,7 @@
 obj-$(CONFIG_ACPI_ALS)		+= acpi-als.o
 obj-$(CONFIG_ADJD_S311)		+= adjd_s311.o
 obj-$(CONFIG_ADUX1020)		+= adux1020.o
+obj-$(CONFIG_AL3000A)		+= al3000a.o
 obj-$(CONFIG_AL3010)		+= al3010.o
 obj-$(CONFIG_AL3320A)		+= al3320a.o
 obj-$(CONFIG_APDS9160)		+= apds9160.o

drivers/iio/light/al3000a.c

@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+
+#include <linux/iio/iio.h>
+
+#define AL3000A_REG_SYSTEM		0x00
+#define AL3000A_REG_DATA		0x05
+
+#define AL3000A_CONFIG_ENABLE		0x00
+#define AL3000A_CONFIG_DISABLE		0x0b
+#define AL3000A_CONFIG_RESET		0x0f
+#define AL3000A_GAIN_MASK		GENMASK(5, 0)
+
+/*
+ * These are pre-calculated lux values based on possible output of sensor
+ * (range 0x00 - 0x3F)
+ */
+static const u32 lux_table[] = {
+	1, 1, 1, 2, 2, 2, 3, 4,					/* 0 - 7 */
+	4, 5, 6, 7, 9, 11, 13, 16,				/* 8 - 15 */
+	19, 22, 27, 32, 39, 46, 56, 67,				/* 16 - 23 */
+	80, 96, 116, 139, 167, 200, 240, 289,			/* 24 - 31 */
+	347, 416, 499, 600, 720, 864, 1037, 1245,		/* 32 - 39 */
+	1495, 1795, 2155, 2587, 3105, 3728, 4475, 5373,		/* 40 - 47 */
+	6450, 7743, 9296, 11160, 13397, 16084, 19309, 23180,	/* 48 - 55 */
+	27828, 33408, 40107, 48148, 57803, 69393, 83306, 100000 /* 56 - 63 */
+};
+
+static const struct regmap_config al3000a_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = AL3000A_REG_DATA,
+};
+
+struct al3000a_data {
+	struct regmap *regmap;
+	struct regulator *vdd_supply;
+};
+
+static const struct iio_chan_spec al3000a_channels[] = {
+	{
+		.type = IIO_LIGHT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+};
+
+static int al3000a_set_pwr_on(struct al3000a_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = regulator_enable(data->vdd_supply);
+	if (ret) {
+		dev_err(dev, "failed to enable vdd power supply\n");
+		return ret;
+	}
+
+	return regmap_write(data->regmap, AL3000A_REG_SYSTEM, AL3000A_CONFIG_ENABLE);
+}
+
+static void al3000a_set_pwr_off(void *_data)
+{
+	struct al3000a_data *data = _data;
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = regmap_write(data->regmap, AL3000A_REG_SYSTEM, AL3000A_CONFIG_DISABLE);
+	if (ret)
+		dev_err(dev, "failed to write system register\n");
+
+	ret = regulator_disable(data->vdd_supply);
+	if (ret)
+		dev_err(dev, "failed to disable vdd power supply\n");
+}
+
+static int al3000a_init(struct al3000a_data *data)
+{
+	int ret;
+
+	ret = al3000a_set_pwr_on(data);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(data->regmap, AL3000A_REG_SYSTEM, AL3000A_CONFIG_RESET);
+	if (ret)
+		return ret;
+
+	return regmap_write(data->regmap, AL3000A_REG_SYSTEM, AL3000A_CONFIG_ENABLE);
+}
+
+static int al3000a_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long mask)
+{
+	struct al3000a_data *data = iio_priv(indio_dev);
+	int ret, gain;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		ret = regmap_read(data->regmap, AL3000A_REG_DATA, &gain);
+		if (ret)
+			return ret;
+
+		*val = lux_table[gain & AL3000A_GAIN_MASK];
+
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info al3000a_info = {
+	.read_raw = al3000a_read_raw,
+};
+
+static int al3000a_probe(struct i2c_client *client)
+{
+	struct al3000a_data *data;
+	struct device *dev = &client->dev;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+
+	data->regmap = devm_regmap_init_i2c(client, &al3000a_regmap_config);
+	if (IS_ERR(data->regmap))
+		return dev_err_probe(dev, PTR_ERR(data->regmap),
+				     "cannot allocate regmap\n");
+
+	data->vdd_supply = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(data->vdd_supply))
+		return dev_err_probe(dev, PTR_ERR(data->vdd_supply),
+				     "failed to get vdd regulator\n");
+
+	indio_dev->info = &al3000a_info;
+	indio_dev->name = "al3000a";
+	indio_dev->channels = al3000a_channels;
+	indio_dev->num_channels = ARRAY_SIZE(al3000a_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = al3000a_init(data);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to init ALS\n");
+
+	ret = devm_add_action_or_reset(dev, al3000a_set_pwr_off, data);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to add action\n");
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static int al3000a_suspend(struct device *dev)
+{
+	struct al3000a_data *data = iio_priv(dev_get_drvdata(dev));
+
+	al3000a_set_pwr_off(data);
+	return 0;
+}
+
+static int al3000a_resume(struct device *dev)
+{
+	struct al3000a_data *data = iio_priv(dev_get_drvdata(dev));
+
+	return al3000a_set_pwr_on(data);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(al3000a_pm_ops, al3000a_suspend, al3000a_resume);
+
+static const struct i2c_device_id al3000a_id[] = {
+	{ "al3000a" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, al3000a_id);
+
+static const struct of_device_id al3000a_of_match[] = {
+	{ .compatible = "dynaimage,al3000a" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, al3000a_of_match);
+
+static struct i2c_driver al3000a_driver = {
+	.driver = {
+		.name = "al3000a",
+		.of_match_table = al3000a_of_match,
+		.pm = pm_sleep_ptr(&al3000a_pm_ops),
+	},
+	.probe = al3000a_probe,
+	.id_table = al3000a_id,
+};
+module_i2c_driver(al3000a_driver);
+
+MODULE_AUTHOR("Svyatolsav Ryhel <clamor95@gmail.com>");
+MODULE_DESCRIPTION("al3000a Ambient Light Sensor driver");
+MODULE_LICENSE("GPL");