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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/iio/temperature/mlx90614.c
Initial import
Diffstat (limited to 'drivers/iio/temperature/mlx90614.c')
-rw-r--r--drivers/iio/temperature/mlx90614.c221
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");