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
25static const int tsys02d_samp_freq[4] = { 20, 40, 70, 140 };
26/* String copy of the above const for readability purpose */
27static const char tsys02d_show_samp_freq[] = "20 40 70 140";
28
29static 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
60static 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
86static 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
94static 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
104static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(tsys02d_show_samp_freq);
105static IIO_DEVICE_ATTR(battery_low, S_IRUGO,
106		       tsys02_read_battery_low, NULL, 0);
107
108static 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
114static const struct attribute_group tsys02d_attribute_group = {
115	.attrs = tsys02d_attributes,
116};
117
118static 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
124static 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->modes = INDIO_DIRECT_MODE;
153	indio_dev->channels = tsys02d_channels;
154	indio_dev->num_channels = ARRAY_SIZE(tsys02d_channels);
155
156	i2c_set_clientdata(client, indio_dev);
157
158	ret = ms_sensors_reset(client, TSYS02D_RESET, 15000);
159	if (ret)
160		return ret;
161
162	ret = ms_sensors_read_serial(client, &serial_number);
163	if (ret)
164		return ret;
165	dev_info(&client->dev, "Serial number : %llx", serial_number);
166
167	return devm_iio_device_register(&client->dev, indio_dev);
168}
169
170static const struct i2c_device_id tsys02d_id[] = {
171	{"tsys02d", 0},
172	{}
173};
174MODULE_DEVICE_TABLE(i2c, tsys02d_id);
175
176static struct i2c_driver tsys02d_driver = {
177	.probe = tsys02d_probe,
178	.id_table = tsys02d_id,
179	.driver = {
180		   .name = "tsys02d",
181		   },
182};
183
184module_i2c_driver(tsys02d_driver);
185
186MODULE_DESCRIPTION("Measurement-Specialties tsys02d temperature driver");
187MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
188MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
189MODULE_LICENSE("GPL v2");
190