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 26 static const int tsys02d_samp_freq[4] = { 20, 40, 70, 140 }; 27 /* String copy of the above const for readability purpose */ 28 static const char tsys02d_show_samp_freq[] = "20 40 70 140"; 29 30 static 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 61 static 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 87 static 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 95 static 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 } 104 105 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(tsys02d_show_samp_freq); 106 static IIO_DEVICE_ATTR(battery_low, S_IRUGO, 107 tsys02_read_battery_low, NULL, 0); 108 109 static 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 }; 114 115 static const struct attribute_group tsys02d_attribute_group = { 116 .attrs = tsys02d_attributes, 117 }; 118 119 static 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 }; 125 126 static 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 } 172 173 static const struct i2c_device_id tsys02d_id[] = { 174 {"tsys02d", 0}, 175 {} 176 }; 177 MODULE_DEVICE_TABLE(i2c, tsys02d_id); 178 179 static struct i2c_driver tsys02d_driver = { 180 .probe = tsys02d_probe, 181 .id_table = tsys02d_id, 182 .driver = { 183 .name = "tsys02d", 184 }, 185 }; 186 187 module_i2c_driver(tsys02d_driver); 188 189 MODULE_DESCRIPTION("Measurement-Specialties tsys02d temperature driver"); 190 MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>"); 191 MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>"); 192 MODULE_LICENSE("GPL v2"); 193