Initial import

1 files changed, 221 insertions, 0 deletions

diff --git a/drivers/iio/temperature/mlx90614.c b/drivers/iio/temperature/mlx90614.c
new file mode 100644
index 000000000..a112fc9ab
--- /dev/null
+++ b/drivers/iio/temperature/mlx90614.c
@@ -0,0 +1,221 @@
+/*
+ * mlx90614.c - Support for Melexis MLX90614 contactless IR temperature sensor
+ *
+ * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
+ * Copyright (c) 2015 Essensium NV
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License.  See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * Driver for the Melexis MLX90614 I2C 16-bit IR thermopile sensor
+ *
+ * (7-bit I2C slave address 0x5a, 100KHz bus speed only!)
+ *
+ * TODO: sleep mode, configuration EEPROM
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+
+#define MLX90614_OP_RAM		0x00
+#define MLX90614_OP_EEPROM	0x20
+#define MLX90614_OP_SLEEP	0xff
+
+/* RAM offsets with 16-bit data, MSB first */
+#define MLX90614_RAW1	(MLX90614_OP_RAM | 0x04) /* raw data IR channel 1 */
+#define MLX90614_RAW2	(MLX90614_OP_RAM | 0x05) /* raw data IR channel 2 */
+#define MLX90614_TA	(MLX90614_OP_RAM | 0x06) /* ambient temperature */
+#define MLX90614_TOBJ1	(MLX90614_OP_RAM | 0x07) /* object 1 temperature */
+#define MLX90614_TOBJ2	(MLX90614_OP_RAM | 0x08) /* object 2 temperature */
+
+/* EEPROM offsets with 16-bit data, MSB first */
+#define MLX90614_EMISSIVITY	(MLX90614_OP_EEPROM | 0x04) /* emissivity correction coefficient */
+#define MLX90614_CONFIG		(MLX90614_OP_EEPROM | 0x05) /* configuration register */
+
+/* Control bits in configuration register */
+#define MLX90614_CONFIG_IIR_SHIFT 0 /* IIR coefficient */
+#define MLX90614_CONFIG_IIR_MASK (0x7 << MLX90614_CONFIG_IIR_SHIFT)
+#define MLX90614_CONFIG_DUAL_SHIFT 6 /* single (0) or dual (1) IR sensor */
+#define MLX90614_CONFIG_DUAL_MASK (1 << MLX90614_CONFIG_DUAL_SHIFT)
+#define MLX90614_CONFIG_FIR_SHIFT 8 /* FIR coefficient */
+#define MLX90614_CONFIG_FIR_MASK (0x7 << MLX90614_CONFIG_FIR_SHIFT)
+#define MLX90614_CONFIG_GAIN_SHIFT 11 /* gain */
+#define MLX90614_CONFIG_GAIN_MASK (0x7 << MLX90614_CONFIG_GAIN_SHIFT)
+
+/* Timings (in ms) */
+#define MLX90614_TIMING_EEPROM 20 /* time for EEPROM write/erase to complete */
+#define MLX90614_TIMING_WAKEUP 34 /* time to hold SDA low for wake-up */
+#define MLX90614_TIMING_STARTUP 250 /* time before first data after wake-up */
+
+struct mlx90614_data {
+	struct i2c_client *client;
+};
+
+static int mlx90614_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *channel, int *val,
+			    int *val2, long mask)
+{
+	struct mlx90614_data *data = iio_priv(indio_dev);
+	u8 cmd;
+	s32 ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW: /* 0.02K / LSB */
+		switch (channel->channel2) {
+		case IIO_MOD_TEMP_AMBIENT:
+			cmd = MLX90614_TA;
+			break;
+		case IIO_MOD_TEMP_OBJECT:
+			switch (channel->channel) {
+			case 0:
+				cmd = MLX90614_TOBJ1;
+				break;
+			case 1:
+				cmd = MLX90614_TOBJ2;
+				break;
+			default:
+				return -EINVAL;
+			}
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		ret = i2c_smbus_read_word_data(data->client, cmd);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = 13657;
+		*val2 = 500000;
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 20;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_chan_spec mlx90614_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.modified = 1,
+		.channel2 = IIO_MOD_TEMP_AMBIENT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
+		    BIT(IIO_CHAN_INFO_SCALE),
+	},
+	{
+		.type = IIO_TEMP,
+		.modified = 1,
+		.channel2 = IIO_MOD_TEMP_OBJECT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
+		    BIT(IIO_CHAN_INFO_SCALE),
+	},
+	{
+		.type = IIO_TEMP,
+		.indexed = 1,
+		.modified = 1,
+		.channel = 1,
+		.channel2 = IIO_MOD_TEMP_OBJECT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
+		    BIT(IIO_CHAN_INFO_SCALE),
+	},
+};
+
+static const struct iio_info mlx90614_info = {
+	.read_raw = mlx90614_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+/* Return 0 for single sensor, 1 for dual sensor, <0 on error. */
+static int mlx90614_probe_num_ir_sensors(struct i2c_client *client)
+{
+	s32 ret;
+
+	ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
+
+	if (ret < 0)
+		return ret;
+
+	return (ret & MLX90614_CONFIG_DUAL_MASK) ? 1 : 0;
+}
+
+static int mlx90614_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct iio_dev *indio_dev;
+	struct mlx90614_data *data;
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	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->name = id->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &mlx90614_info;
+
+	ret = mlx90614_probe_num_ir_sensors(client);
+	switch (ret) {
+	case 0:
+		dev_dbg(&client->dev, "Found single sensor");
+		indio_dev->channels = mlx90614_channels;
+		indio_dev->num_channels = 2;
+		break;
+	case 1:
+		dev_dbg(&client->dev, "Found dual sensor");
+		indio_dev->channels = mlx90614_channels;
+		indio_dev->num_channels = 3;
+		break;
+	default:
+		return ret;
+	}
+
+	return iio_device_register(indio_dev);
+}
+
+static int mlx90614_remove(struct i2c_client *client)
+{
+	iio_device_unregister(i2c_get_clientdata(client));
+
+	return 0;
+}
+
+static const struct i2c_device_id mlx90614_id[] = {
+	{ "mlx90614", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mlx90614_id);
+
+static struct i2c_driver mlx90614_driver = {
+	.driver = {
+		.name	= "mlx90614",
+		.owner	= THIS_MODULE,
+	},
+	.probe = mlx90614_probe,
+	.remove = mlx90614_remove,
+	.id_table = mlx90614_id,
+};
+module_i2c_driver(mlx90614_driver);
+
+MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
+MODULE_AUTHOR("Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>");
+MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver");
+MODULE_LICENSE("GPL");