1 files changed, 248 insertions, 0 deletions
diff --git a/drivers/iio/chemical/atlas-ezo-sensor.c b/drivers/iio/chemical/atlas-ezo-sensor.c
new file mode 100644
index 000000000..bbcf5a59c
--- /dev/null
+++ b/drivers/iio/chemical/atlas-ezo-sensor.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * atlas-ezo-sensor.c - Support for Atlas Scientific EZO sensors
+ *
+ * Copyright (C) 2020 Konsulko Group
+ * Author: Matt Ranostay <matt.ranostay@konsulko.com>
+ */
+
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+
+#include <linux/iio/iio.h>
+
+#define ATLAS_EZO_DRV_NAME		"atlas-ezo-sensor"
+#define ATLAS_INT_TIME_IN_MS		950
+#define ATLAS_INT_HUM_TIME_IN_MS	350
+
+enum {
+	ATLAS_CO2_EZO,
+	ATLAS_O2_EZO,
+	ATLAS_HUM_EZO,
+};
+
+struct atlas_ezo_device {
+	const struct iio_chan_spec *channels;
+	int num_channels;
+	int delay;
+};
+
+struct atlas_ezo_data {
+	struct i2c_client *client;
+	const struct atlas_ezo_device *chip;
+
+	/* lock to avoid multiple concurrent read calls */
+	struct mutex lock;
+
+	u8 buffer[8];
+};
+
+#define ATLAS_CONCENTRATION_CHANNEL(_modifier) \
+	{ \
+		.type = IIO_CONCENTRATION, \
+		.modified = 1,\
+		.channel2 = _modifier, \
+		.info_mask_separate = \
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \
+		.scan_index = 0, \
+		.scan_type =  { \
+			.sign = 'u', \
+			.realbits = 32, \
+			.storagebits = 32, \
+			.endianness = IIO_CPU, \
+		}, \
+	}
+
+static const struct iio_chan_spec atlas_co2_ezo_channels[] = {
+	ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_CO2),
+};
+
+static const struct iio_chan_spec atlas_o2_ezo_channels[] = {
+	ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_O2),
+};
+
+static const struct iio_chan_spec atlas_hum_ezo_channels[] = {
+	{
+		.type = IIO_HUMIDITYRELATIVE,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 0,
+		.scan_type =  {
+			.sign = 'u',
+			.realbits = 32,
+			.storagebits = 32,
+			.endianness = IIO_CPU,
+		},
+	},
+};
+
+static struct atlas_ezo_device atlas_ezo_devices[] = {
+	[ATLAS_CO2_EZO] = {
+		.channels = atlas_co2_ezo_channels,
+		.num_channels = 1,
+		.delay = ATLAS_INT_TIME_IN_MS,
+	},
+	[ATLAS_O2_EZO] = {
+		.channels = atlas_o2_ezo_channels,
+		.num_channels = 1,
+		.delay = ATLAS_INT_TIME_IN_MS,
+	},
+	[ATLAS_HUM_EZO] = {
+		.channels = atlas_hum_ezo_channels,
+		.num_channels = 1,
+		.delay = ATLAS_INT_HUM_TIME_IN_MS,
+	},
+};
+
+static void atlas_ezo_sanitize(char *buf)
+{
+	char *ptr = strchr(buf, '.');
+
+	if (!ptr)
+		return;
+
+	memmove(ptr, ptr + 1, strlen(ptr));
+}
+
+static int atlas_ezo_read_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan,
+			  int *val, int *val2, long mask)
+{
+	struct atlas_ezo_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+
+	if (chan->type != IIO_CONCENTRATION)
+		return -EINVAL;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW: {
+		int ret;
+		long tmp;
+
+		mutex_lock(&data->lock);
+
+		tmp = i2c_smbus_write_byte(client, 'R');
+
+		if (tmp < 0) {
+			mutex_unlock(&data->lock);
+			return tmp;
+		}
+
+		msleep(data->chip->delay);
+
+		tmp = i2c_master_recv(client, data->buffer, sizeof(data->buffer));
+
+		if (tmp < 0 || data->buffer[0] != 1) {
+			mutex_unlock(&data->lock);
+			return -EBUSY;
+		}
+
+		/* removing floating point for fixed number representation */
+		atlas_ezo_sanitize(data->buffer + 2);
+
+		ret = kstrtol(data->buffer + 1, 10, &tmp);
+
+		*val = tmp;
+
+		mutex_unlock(&data->lock);
+
+		return ret ? ret : IIO_VAL_INT;
+	}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_HUMIDITYRELATIVE:
+			*val = 10;
+			return IIO_VAL_INT;
+		case IIO_CONCENTRATION:
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		/* IIO_CONCENTRATION modifiers */
+		switch (chan->channel2) {
+		case IIO_MOD_CO2:
+			*val = 0;
+			*val2 = 100; /* 0.0001 */
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_MOD_O2:
+			*val = 100;
+			return IIO_VAL_INT;
+		}
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct iio_info atlas_info = {
+	.read_raw = atlas_ezo_read_raw,
+};
+
+static const struct i2c_device_id atlas_ezo_id[] = {
+	{ "atlas-co2-ezo", (kernel_ulong_t)&atlas_ezo_devices[ATLAS_CO2_EZO] },
+	{ "atlas-o2-ezo", (kernel_ulong_t)&atlas_ezo_devices[ATLAS_O2_EZO] },
+	{ "atlas-hum-ezo", (kernel_ulong_t)&atlas_ezo_devices[ATLAS_HUM_EZO] },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, atlas_ezo_id);
+
+static const struct of_device_id atlas_ezo_dt_ids[] = {
+	{ .compatible = "atlas,co2-ezo", .data = &atlas_ezo_devices[ATLAS_CO2_EZO], },
+	{ .compatible = "atlas,o2-ezo", .data = &atlas_ezo_devices[ATLAS_O2_EZO], },
+	{ .compatible = "atlas,hum-ezo", .data = &atlas_ezo_devices[ATLAS_HUM_EZO], },
+	{}
+};
+MODULE_DEVICE_TABLE(of, atlas_ezo_dt_ids);
+
+static int atlas_ezo_probe(struct i2c_client *client,
+		       const struct i2c_device_id *id)
+{
+	const struct atlas_ezo_device *chip;
+	struct atlas_ezo_data *data;
+	struct iio_dev *indio_dev;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	if (dev_fwnode(&client->dev))
+		chip = device_get_match_data(&client->dev);
+	else
+		chip = (const struct atlas_ezo_device *)id->driver_data;
+	if (!chip)
+		return -EINVAL;
+
+	indio_dev->info = &atlas_info;
+	indio_dev->name = ATLAS_EZO_DRV_NAME;
+	indio_dev->channels = chip->channels;
+	indio_dev->num_channels = chip->num_channels;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	data->chip = chip;
+	mutex_init(&data->lock);
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+};
+
+static struct i2c_driver atlas_ezo_driver = {
+	.driver = {
+		.name	= ATLAS_EZO_DRV_NAME,
+		.of_match_table	= atlas_ezo_dt_ids,
+	},
+	.probe		= atlas_ezo_probe,
+	.id_table	= atlas_ezo_id,
+};
+module_i2c_driver(atlas_ezo_driver);
+
+MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
+MODULE_DESCRIPTION("Atlas Scientific EZO sensors");
+MODULE_LICENSE("GPL");