kernel/drivers/iio/pressure/ms5637.c

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