linux/drivers/iio/temperature/tsys02d.c
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   1/*
   2 * tsys02d.c - Support for Measurement-Specialties tsys02d temperature sensor
   3 *
   4 * Copyright (c) 2015 Measurement-Specialties
   5 *
   6 * Licensed under the GPL-2.
   7 *
   8 * (7-bit I2C slave address 0x40)
   9 *
  10 * Datasheet:
  11 *  http://www.meas-spec.com/downloads/Digital_Sensor_TSYS02D.pdf
  12 */
  13
  14#include <linux/init.h>
  15#include <linux/device.h>
  16#include <linux/kernel.h>
  17#include <linux/stat.h>
  18#include <linux/module.h>
  19#include <linux/iio/iio.h>
  20#include <linux/iio/sysfs.h>
  21
  22#include "../common/ms_sensors/ms_sensors_i2c.h"
  23
  24#define TSYS02D_RESET                           0xFE
  25
  26static const int tsys02d_samp_freq[4] = { 20, 40, 70, 140 };
  27/* String copy of the above const for readability purpose */
  28static const char tsys02d_show_samp_freq[] = "20 40 70 140";
  29
  30static int tsys02d_read_raw(struct iio_dev *indio_dev,
  31                            struct iio_chan_spec const *channel, int *val,
  32                            int *val2, long mask)
  33{
  34        int ret;
  35        s32 temperature;
  36        struct ms_ht_dev *dev_data = iio_priv(indio_dev);
  37
  38        switch (mask) {
  39        case IIO_CHAN_INFO_PROCESSED:
  40                switch (channel->type) {
  41                case IIO_TEMP:  /* in milli °C */
  42                        ret = ms_sensors_ht_read_temperature(dev_data,
  43                                                             &temperature);
  44                        if (ret)
  45                                return ret;
  46                        *val = temperature;
  47
  48                        return IIO_VAL_INT;
  49                default:
  50                        return -EINVAL;
  51                }
  52        case IIO_CHAN_INFO_SAMP_FREQ:
  53                *val = tsys02d_samp_freq[dev_data->res_index];
  54
  55                return IIO_VAL_INT;
  56        default:
  57                return -EINVAL;
  58        }
  59}
  60
  61static int tsys02d_write_raw(struct iio_dev *indio_dev,
  62                             struct iio_chan_spec const *chan,
  63                             int val, int val2, long mask)
  64{
  65        struct ms_ht_dev *dev_data = iio_priv(indio_dev);
  66        int i, ret;
  67
  68        switch (mask) {
  69        case IIO_CHAN_INFO_SAMP_FREQ:
  70                i = ARRAY_SIZE(tsys02d_samp_freq);
  71                while (i-- > 0)
  72                        if (val == tsys02d_samp_freq[i])
  73                                break;
  74                if (i < 0)
  75                        return -EINVAL;
  76                mutex_lock(&dev_data->lock);
  77                dev_data->res_index = i;
  78                ret = ms_sensors_write_resolution(dev_data, i);
  79                mutex_unlock(&dev_data->lock);
  80
  81                return ret;
  82        default:
  83                return -EINVAL;
  84        }
  85}
  86
  87static const struct iio_chan_spec tsys02d_channels[] = {
  88        {
  89                .type = IIO_TEMP,
  90                .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
  91                .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
  92        }
  93};
  94
  95static ssize_t tsys02_read_battery_low(struct device *dev,
  96                                       struct device_attribute *attr,
  97                                       char *buf)
  98{
  99        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 100        struct ms_ht_dev *dev_data = iio_priv(indio_dev);
 101
 102        return ms_sensors_show_battery_low(dev_data, buf);
 103}
 104
 105static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(tsys02d_show_samp_freq);
 106static IIO_DEVICE_ATTR(battery_low, S_IRUGO,
 107                       tsys02_read_battery_low, NULL, 0);
 108
 109static struct attribute *tsys02d_attributes[] = {
 110        &iio_const_attr_sampling_frequency_available.dev_attr.attr,
 111        &iio_dev_attr_battery_low.dev_attr.attr,
 112        NULL,
 113};
 114
 115static const struct attribute_group tsys02d_attribute_group = {
 116        .attrs = tsys02d_attributes,
 117};
 118
 119static const struct iio_info tsys02d_info = {
 120        .read_raw = tsys02d_read_raw,
 121        .write_raw = tsys02d_write_raw,
 122        .attrs = &tsys02d_attribute_group,
 123        .driver_module = THIS_MODULE,
 124};
 125
 126static int tsys02d_probe(struct i2c_client *client,
 127                         const struct i2c_device_id *id)
 128{
 129        struct ms_ht_dev *dev_data;
 130        struct iio_dev *indio_dev;
 131        int ret;
 132        u64 serial_number;
 133
 134        if (!i2c_check_functionality(client->adapter,
 135                                     I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
 136                                     I2C_FUNC_SMBUS_WRITE_BYTE |
 137                                     I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
 138                dev_err(&client->dev,
 139                        "Adapter does not support some i2c transaction\n");
 140                return -EOPNOTSUPP;
 141        }
 142
 143        indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
 144        if (!indio_dev)
 145                return -ENOMEM;
 146
 147        dev_data = iio_priv(indio_dev);
 148        dev_data->client = client;
 149        dev_data->res_index = 0;
 150        mutex_init(&dev_data->lock);
 151
 152        indio_dev->info = &tsys02d_info;
 153        indio_dev->name = id->name;
 154        indio_dev->dev.parent = &client->dev;
 155        indio_dev->modes = INDIO_DIRECT_MODE;
 156        indio_dev->channels = tsys02d_channels;
 157        indio_dev->num_channels = ARRAY_SIZE(tsys02d_channels);
 158
 159        i2c_set_clientdata(client, indio_dev);
 160
 161        ret = ms_sensors_reset(client, TSYS02D_RESET, 15000);
 162        if (ret)
 163                return ret;
 164
 165        ret = ms_sensors_read_serial(client, &serial_number);
 166        if (ret)
 167                return ret;
 168        dev_info(&client->dev, "Serial number : %llx", serial_number);
 169
 170        return devm_iio_device_register(&client->dev, indio_dev);
 171}
 172
 173static const struct i2c_device_id tsys02d_id[] = {
 174        {"tsys02d", 0},
 175        {}
 176};
 177MODULE_DEVICE_TABLE(i2c, tsys02d_id);
 178
 179static struct i2c_driver tsys02d_driver = {
 180        .probe = tsys02d_probe,
 181        .id_table = tsys02d_id,
 182        .driver = {
 183                   .name = "tsys02d",
 184                   },
 185};
 186
 187module_i2c_driver(tsys02d_driver);
 188
 189MODULE_DESCRIPTION("Measurement-Specialties tsys02d temperature driver");
 190MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
 191MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
 192MODULE_LICENSE("GPL v2");
 193