iio: mlx90614: Support devices with dual IR sensor

The model is detected by reading the EEPROM configuration during
probing.

Signed-off-by: Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>
Cc: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 57 insertions, 10 deletions

diff --git a/drivers/iio/temperature/mlx90614.c b/drivers/iio/temperature/mlx90614.c
index a2e3aa6aa39d..a112fc9abf43 100644
--- a/drivers/iio/temperature/mlx90614.c
+++ b/drivers/iio/temperature/mlx90614.c
@@ -2,6 +2,7 @@
  * 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
@@ -59,26 +60,34 @@ static int mlx90614_read_raw(struct iio_dev *indio_dev,
                             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:
-                        ret = i2c_smbus_read_word_data(data->client,
-                            MLX90614_TA);
-                        if (ret < 0)
-                                return ret;
+                        cmd = MLX90614_TA;
                         break;
                 case IIO_MOD_TEMP_OBJECT:
-                        ret = i2c_smbus_read_word_data(data->client,
-                            MLX90614_TOBJ1);
-                        if (ret < 0)
-                                return ret;
+                        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:
@@ -110,6 +119,16 @@ static const struct iio_chan_spec mlx90614_channels[] = {
                 .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 = {
@@ -117,11 +136,25 @@ static const struct iio_info mlx90614_info = {
         .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;
@@ -139,8 +172,21 @@ static int mlx90614_probe(struct i2c_client *client,
         indio_dev->modes = INDIO_DIRECT_MODE;
         indio_dev->info = &mlx90614_info;
 
-        indio_dev->channels = mlx90614_channels;
-        indio_dev->num_channels = ARRAY_SIZE(mlx90614_channels);
+        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);
 }
@@ -170,5 +216,6 @@ static struct i2c_driver mlx90614_driver = {
 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");