drivers/iio/pressure/ms5637.c

   1 /*
   2  * ms5637.c - Support for Measurement-Specialties MS5637, MS5805
   3  *            MS5837 and MS8607 pressure & temperature sensor
   4  *
   5  * Copyright (c) 2015 Measurement-Specialties
   6  *
   7  * Licensed under the GPL-2.
   8  *
   9  * (7-bit I2C slave address 0x76)
  10  *
  11  * Datasheet:
  12  *  http://www.meas-spec.com/downloads/MS5637-02BA03.pdf
  13  * Datasheet:
  14  *  http://www.meas-spec.com/downloads/MS5805-02BA01.pdf
  15  * Datasheet:
  16  *  http://www.meas-spec.com/downloads/MS5837-30BA.pdf
  17  * Datasheet:
  18  *  http://www.meas-spec.com/downloads/MS8607-02BA01.pdf
  19  */
  20
  21 #include <linux/init.h>
  22 #include <linux/device.h>
  23 #include <linux/kernel.h>
  24 #include <linux/stat.h>
  25 #include <linux/module.h>
  26 #include <linux/i2c.h>
  27 #include <linux/iio/iio.h>
  28 #include <linux/iio/sysfs.h>
  29 #include <linux/mutex.h>
  30
  31 #include "../common/ms_sensors/ms_sensors_i2c.h"
  32
  33 static const int ms5637_samp_freq[6] = { 960, 480, 240, 120, 60, 30 };
  34 /* String copy of the above const for readability purpose */
  35 static const char ms5637_show_samp_freq[] = "960 480 240 120 60 30";
  36
  37 static int ms5637_read_raw(struct iio_dev *indio_dev,
  38                            struct iio_chan_spec const *channel, int *val,
  39                            int *val2, long mask)
  40 {
  41         int ret;
  42         int temperature;
  43         unsigned int pressure;
  44         struct ms_tp_dev *dev_data = iio_priv(indio_dev);
  45
  46         switch (mask) {
  47         case IIO_CHAN_INFO_PROCESSED:
  48                 ret = ms_sensors_read_temp_and_pressure(dev_data,
  49                                                         &temperature,
  50                                                         &pressure);
  51                 if (ret)
  52                         return ret;
  53
  54                 switch (channel->type) {
  55                 case IIO_TEMP:  /* in milli °C */
  56                         *val = temperature;
  57
  58                         return IIO_VAL_INT;
  59                 case IIO_PRESSURE:      /* in kPa */
  60                         *val = pressure / 1000;
  61                         *val2 = (pressure % 1000) * 1000;
  62
  63                         return IIO_VAL_INT_PLUS_MICRO;
  64                 default:
  65                         return -EINVAL;
  66                 }
  67         case IIO_CHAN_INFO_SAMP_FREQ:
  68                 *val = ms5637_samp_freq[dev_data->res_index];
  69
  70                 return IIO_VAL_INT;
  71         default:
  72                 return -EINVAL;
  73         }
  74 }
  75
  76 static int ms5637_write_raw(struct iio_dev *indio_dev,
  77                             struct iio_chan_spec const *chan,
  78                             int val, int val2, long mask)
  79 {
  80         struct ms_tp_dev *dev_data = iio_priv(indio_dev);
  81         int i;
  82
  83         switch (mask) {
  84         case IIO_CHAN_INFO_SAMP_FREQ:
  85                 i = ARRAY_SIZE(ms5637_samp_freq);
  86                 while (i-- > 0)
  87                         if (val == ms5637_samp_freq[i])
  88                                 break;
  89                 if (i < 0)
  90                         return -EINVAL;
  91                 dev_data->res_index = i;
  92
  93                 return 0;
  94         default:
  95                 return -EINVAL;
  96         }
  97 }
  98
  99 static const struct iio_chan_spec ms5637_channels[] = {
 100         {
 101                 .type = IIO_TEMP,
 102                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
 103                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 104         },
 105         {
 106                 .type = IIO_PRESSURE,
 107                 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
 108                 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 109         }
 110 };
 111
 112 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(ms5637_show_samp_freq);
 113
 114 static struct attribute *ms5637_attributes[] = {
 115         &iio_const_attr_sampling_frequency_available.dev_attr.attr,
 116         NULL,
 117 };
 118
 119 static const struct attribute_group ms5637_attribute_group = {
 120         .attrs = ms5637_attributes,
 121 };
 122
 123 static const struct iio_info ms5637_info = {
 124         .read_raw = ms5637_read_raw,
 125         .write_raw = ms5637_write_raw,
 126         .attrs = &ms5637_attribute_group,
 127         .driver_module = THIS_MODULE,
 128 };
 129
 130 static int ms5637_probe(struct i2c_client *client,
 131                         const struct i2c_device_id *id)
 132 {
 133         struct ms_tp_dev *dev_data;
 134         struct iio_dev *indio_dev;
 135         int ret;
 136
 137         if (!i2c_check_functionality(client->adapter,
 138                                      I2C_FUNC_SMBUS_READ_WORD_DATA |
 139                                      I2C_FUNC_SMBUS_WRITE_BYTE |
 140                                      I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
 141                 dev_err(&client->dev,
 142                         "Adapter does not support some i2c transaction\n");
 143                 return -EOPNOTSUPP;
 144         }
 145
 146         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
 147         if (!indio_dev)
 148                 return -ENOMEM;
 149
 150         dev_data = iio_priv(indio_dev);
 151         dev_data->client = client;
 152         dev_data->res_index = 5;
 153         mutex_init(&dev_data->lock);
 154
 155         indio_dev->info = &ms5637_info;
 156         indio_dev->name = id->name;
 157         indio_dev->dev.parent = &client->dev;
 158         indio_dev->modes = INDIO_DIRECT_MODE;
 159         indio_dev->channels = ms5637_channels;
 160         indio_dev->num_channels = ARRAY_SIZE(ms5637_channels);
 161
 162         i2c_set_clientdata(client, indio_dev);
 163
 164         ret = ms_sensors_reset(client, 0x1E, 3000);
 165         if (ret)
 166                 return ret;
 167
 168         ret = ms_sensors_tp_read_prom(dev_data);
 169         if (ret)
 170                 return ret;
 171
 172         return devm_iio_device_register(&client->dev, indio_dev);
 173 }
 174
 175 static const struct i2c_device_id ms5637_id[] = {
 176         {"ms5637", 0},
 177         {"ms5805", 0},
 178         {"ms5837", 0},
 179         {"ms8607-temppressure", 0},
 180         {}
 181 };
 182 MODULE_DEVICE_TABLE(i2c, ms5637_id);
 183
 184 static struct i2c_driver ms5637_driver = {
 185         .probe = ms5637_probe,
 186         .id_table = ms5637_id,
 187         .driver = {
 188                    .name = "ms5637"
 189                    },
 190 };
 191
 192 module_i2c_driver(ms5637_driver);
 193
 194 MODULE_DESCRIPTION("Measurement-Specialties ms5637 temperature & pressure driver");
 195 MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
 196 MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
 197 MODULE_LICENSE("GPL v2");