[PATCH v1 2/3] iio: light: Add support for AL3000a illuminance sensor

[Svyatoslav Ryhel <clamor95@gmail.com>]

AL3000a is a simple I2C-based ambient light sensor, which is
closely related to AL3010 and AL3320a, but has significantly
different hardware configuration.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 drivers/iio/light/Kconfig   |  10 ++
 drivers/iio/light/Makefile  |   1 +
 drivers/iio/light/al3000a.c | 214 ++++++++++++++++++++++++++++++++++++
 3 files changed, 225 insertions(+)
 create mode 100644 drivers/iio/light/al3000a.c

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index e34e551eef3e..142f7f7ef0ec 100644
--- a/drivers/iio/light/Kconfig
+++ b/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
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 11a4041b918a..17030a4cc340 100644
--- a/drivers/iio/light/Makefile
+++ b/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_APDS9300)		+= apds9300.o
diff --git a/drivers/iio/light/al3000a.c b/drivers/iio/light/al3000a.c
new file mode 100644
index 000000000000..9e1f2ac6a933
--- /dev/null
+++ b/drivers/iio/light/al3000a.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AL3000a - Dyna Image Ambient Light Sensor
+ */
+
+#include <linux/bitfield.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define AL3000A_DRV_NAME		"al3000a"
+#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
+
+/*
+ * This are pre-calculated lux values based on possible output
+ * of sensor (range 0x00 - 0x3F)
+ */
+static const u32 lux_table[64] = {
+	1, 1, 1, 2, 2, 2, 3, 4, 4, 5, 6, 7, 9, 11, 13, 16,
+	19, 22, 27, 32, 39, 46, 56, 67, 80, 96, 116, 139,
+	167, 200, 240, 289, 347, 416, 499, 600, 720, 864,
+	1037, 1245, 1495, 1795, 2155, 2587, 3105, 3728,	4475,
+	5373, 6450, 7743, 9296, 11160, 13397, 16084, 19309,
+	23180, 27828, 33408, 40107, 48148, 57803, 69393,
+	83306, 100000
+};
+
+struct al3000a_data {
+	struct i2c_client *client;
+	struct regulator *vdd_supply;
+};
+
+static const struct iio_chan_spec al3000a_channels[] = {
+	{
+		.type = IIO_LIGHT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+	}
+};
+
+static int al3000a_set_pwr(struct al3000a_data *data, bool pwr)
+{
+	struct device *dev = &data->client->dev;
+	u8 val = pwr ? AL3000A_CONFIG_ENABLE : AL3000A_CONFIG_DISABLE;
+	int ret;
+
+	if (pwr) {
+		ret = regulator_enable(data->vdd_supply);
+		if (ret < 0) {
+			dev_err(dev, "failed to enable vdd power supply\n");
+			return ret;
+		}
+	}
+
+	ret = i2c_smbus_write_byte_data(data->client, AL3000A_REG_SYSTEM, val);
+	if (ret < 0) {
+		dev_err(dev, "failed to write system register\n");
+		return ret;
+	}
+
+	if (!pwr) {
+		ret = regulator_disable(data->vdd_supply);
+		if (ret < 0) {
+			dev_err(dev, "failed to disable vdd power supply\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void al3000a_set_pwr_off(void *_data)
+{
+	struct al3000a_data *data = _data;
+
+	al3000a_set_pwr(data, false);
+}
+
+static int al3000a_init(struct al3000a_data *data)
+{
+	int ret;
+
+	ret = al3000a_set_pwr(data, true);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, AL3000A_REG_SYSTEM,
+					AL3000A_CONFIG_RESET);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, AL3000A_REG_SYSTEM,
+					AL3000A_CONFIG_ENABLE);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+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;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = i2c_smbus_read_byte_data(data->client,
+					       AL3000A_REG_DATA);
+		if (ret < 0)
+			return ret;
+
+		*val = lux_table[ret & 0x3F];
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 1;
+
+		return IIO_VAL_INT;
+	default:
+		break;
+	}
+
+	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 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;
+
+	data->vdd_supply = devm_regulator_get(&client->dev, "vdd");
+	if (IS_ERR(data->vdd_supply))
+		return dev_err_probe(&client->dev, PTR_ERR(data->vdd_supply),
+				     "failed to get vdd regulator\n");
+
+	indio_dev->info = &al3000a_info;
+	indio_dev->name = AL3000A_DRV_NAME;
+	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 < 0)
+		return dev_err_probe(&client->dev, ret,
+				     "failed to init ALS\n");
+
+	ret = devm_add_action_or_reset(&client->dev, al3000a_set_pwr_off,
+				       data);
+	if (ret < 0)
+		return dev_err_probe(&client->dev, ret,
+				     "failed to add action\n");
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static int al3000a_suspend(struct device *dev)
+{
+	struct al3000a_data *data = iio_priv(dev_get_drvdata(dev));
+
+	return al3000a_set_pwr(data, false);
+}
+
+static int al3000a_resume(struct device *dev)
+{
+	struct al3000a_data *data = iio_priv(dev_get_drvdata(dev));
+
+	return al3000a_set_pwr(data, true);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(al3000a_pm_ops, al3000a_suspend, al3000a_resume);
+
+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_DRV_NAME,
+		.of_match_table = al3000a_of_match,
+		.pm = pm_sleep_ptr(&al3000a_pm_ops),
+	},
+	.probe = al3000a_probe,
+};
+module_i2c_driver(al3000a_driver);
+
+MODULE_AUTHOR("Svyatolsav Ryhel <clamor95@gmail.com>");
+MODULE_DESCRIPTION("al3000a Ambient Light Sensor driver");
+MODULE_LICENSE("GPL");
-- 
2.43.0