1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * tsys02d.c - Support for Measurement-Specialties tsys02d temperature sensor
4  *
5  * Copyright (c) 2015 Measurement-Specialties
6  *
7  * (7-bit I2C slave address 0x40)
8  *
9  * Datasheet:
10  *  http://www.meas-spec.com/downloads/Digital_Sensor_TSYS02D.pdf
11  */
12 
13 #include <linux/init.h>
14 #include <linux/device.h>
15 #include <linux/kernel.h>
16 #include <linux/stat.h>
17 #include <linux/module.h>
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 
21 #include "../common/ms_sensors/ms_sensors_i2c.h"
22 
23 #define TSYS02D_RESET				0xFE
24 
25 static const int tsys02d_samp_freq[4] = { 20, 40, 70, 140 };
26 /* String copy of the above const for readability purpose */
27 static const char tsys02d_show_samp_freq[] = "20 40 70 140";
28 
29 static int tsys02d_read_raw(struct iio_dev *indio_dev,
30 			    struct iio_chan_spec const *channel, int *val,
31 			    int *val2, long mask)
32 {
33 	int ret;
34 	s32 temperature;
35 	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
36 
37 	switch (mask) {
38 	case IIO_CHAN_INFO_PROCESSED:
39 		switch (channel->type) {
40 		case IIO_TEMP:	/* in milli °C */
41 			ret = ms_sensors_ht_read_temperature(dev_data,
42 							     &temperature);
43 			if (ret)
44 				return ret;
45 			*val = temperature;
46 
47 			return IIO_VAL_INT;
48 		default:
49 			return -EINVAL;
50 		}
51 	case IIO_CHAN_INFO_SAMP_FREQ:
52 		*val = tsys02d_samp_freq[dev_data->res_index];
53 
54 		return IIO_VAL_INT;
55 	default:
56 		return -EINVAL;
57 	}
58 }
59 
60 static int tsys02d_write_raw(struct iio_dev *indio_dev,
61 			     struct iio_chan_spec const *chan,
62 			     int val, int val2, long mask)
63 {
64 	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
65 	int i, ret;
66 
67 	switch (mask) {
68 	case IIO_CHAN_INFO_SAMP_FREQ:
69 		i = ARRAY_SIZE(tsys02d_samp_freq);
70 		while (i-- > 0)
71 			if (val == tsys02d_samp_freq[i])
72 				break;
73 		if (i < 0)
74 			return -EINVAL;
75 		mutex_lock(&dev_data->lock);
76 		dev_data->res_index = i;
77 		ret = ms_sensors_write_resolution(dev_data, i);
78 		mutex_unlock(&dev_data->lock);
79 
80 		return ret;
81 	default:
82 		return -EINVAL;
83 	}
84 }
85 
86 static const struct iio_chan_spec tsys02d_channels[] = {
87 	{
88 		.type = IIO_TEMP,
89 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
90 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
91 	}
92 };
93 
94 static ssize_t tsys02_read_battery_low(struct device *dev,
95 				       struct device_attribute *attr,
96 				       char *buf)
97 {
98 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
99 	struct ms_ht_dev *dev_data = iio_priv(indio_dev);
100 
101 	return ms_sensors_show_battery_low(dev_data, buf);
102 }
103 
104 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(tsys02d_show_samp_freq);
105 static IIO_DEVICE_ATTR(battery_low, S_IRUGO,
106 		       tsys02_read_battery_low, NULL, 0);
107 
108 static struct attribute *tsys02d_attributes[] = {
109 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
110 	&iio_dev_attr_battery_low.dev_attr.attr,
111 	NULL,
112 };
113 
114 static const struct attribute_group tsys02d_attribute_group = {
115 	.attrs = tsys02d_attributes,
116 };
117 
118 static const struct iio_info tsys02d_info = {
119 	.read_raw = tsys02d_read_raw,
120 	.write_raw = tsys02d_write_raw,
121 	.attrs = &tsys02d_attribute_group,
122 };
123 
124 static int tsys02d_probe(struct i2c_client *client,
125 			 const struct i2c_device_id *id)
126 {
127 	struct ms_ht_dev *dev_data;
128 	struct iio_dev *indio_dev;
129 	int ret;
130 	u64 serial_number;
131 
132 	if (!i2c_check_functionality(client->adapter,
133 				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
134 				     I2C_FUNC_SMBUS_WRITE_BYTE |
135 				     I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
136 		dev_err(&client->dev,
137 			"Adapter does not support some i2c transaction\n");
138 		return -EOPNOTSUPP;
139 	}
140 
141 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
142 	if (!indio_dev)
143 		return -ENOMEM;
144 
145 	dev_data = iio_priv(indio_dev);
146 	dev_data->client = client;
147 	dev_data->res_index = 0;
148 	mutex_init(&dev_data->lock);
149 
150 	indio_dev->info = &tsys02d_info;
151 	indio_dev->name = id->name;
152 	indio_dev->dev.parent = &client->dev;
153 	indio_dev->modes = INDIO_DIRECT_MODE;
154 	indio_dev->channels = tsys02d_channels;
155 	indio_dev->num_channels = ARRAY_SIZE(tsys02d_channels);
156 
157 	i2c_set_clientdata(client, indio_dev);
158 
159 	ret = ms_sensors_reset(client, TSYS02D_RESET, 15000);
160 	if (ret)
161 		return ret;
162 
163 	ret = ms_sensors_read_serial(client, &serial_number);
164 	if (ret)
165 		return ret;
166 	dev_info(&client->dev, "Serial number : %llx", serial_number);
167 
168 	return devm_iio_device_register(&client->dev, indio_dev);
169 }
170 
171 static const struct i2c_device_id tsys02d_id[] = {
172 	{"tsys02d", 0},
173 	{}
174 };
175 MODULE_DEVICE_TABLE(i2c, tsys02d_id);
176 
177 static struct i2c_driver tsys02d_driver = {
178 	.probe = tsys02d_probe,
179 	.id_table = tsys02d_id,
180 	.driver = {
181 		   .name = "tsys02d",
182 		   },
183 };
184 
185 module_i2c_driver(tsys02d_driver);
186 
187 MODULE_DESCRIPTION("Measurement-Specialties tsys02d temperature 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");
191