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15#include <linux/err.h>
16#include <linux/i2c.h>
17#include <linux/delay.h>
18#include <linux/module.h>
19#include <linux/pm.h>
20
21#include <linux/iio/iio.h>
22#include <linux/iio/sysfs.h>
23
24#define SI7005_STATUS 0x00
25#define SI7005_DATA 0x01
26#define SI7005_CONFIG 0x03
27#define SI7005_ID 0x11
28
29#define SI7005_STATUS_NRDY BIT(0)
30#define SI7005_CONFIG_TEMP BIT(4)
31#define SI7005_CONFIG_START BIT(0)
32
33#define SI7005_ID_7005 0x50
34#define SI7005_ID_7015 0xf0
35
36struct si7005_data {
37 struct i2c_client *client;
38 struct mutex lock;
39 u8 config;
40};
41
42static int si7005_read_measurement(struct si7005_data *data, bool temp)
43{
44 int tries = 50;
45 int ret;
46
47 mutex_lock(&data->lock);
48
49 ret = i2c_smbus_write_byte_data(data->client, SI7005_CONFIG,
50 data->config | SI7005_CONFIG_START |
51 (temp ? SI7005_CONFIG_TEMP : 0));
52 if (ret < 0)
53 goto done;
54
55 while (tries-- > 0) {
56 msleep(20);
57 ret = i2c_smbus_read_byte_data(data->client, SI7005_STATUS);
58 if (ret < 0)
59 goto done;
60 if (!(ret & SI7005_STATUS_NRDY))
61 break;
62 }
63 if (tries < 0) {
64 ret = -EIO;
65 goto done;
66 }
67
68 ret = i2c_smbus_read_word_swapped(data->client, SI7005_DATA);
69
70done:
71 mutex_unlock(&data->lock);
72
73 return ret;
74}
75
76static int si7005_read_raw(struct iio_dev *indio_dev,
77 struct iio_chan_spec const *chan, int *val,
78 int *val2, long mask)
79{
80 struct si7005_data *data = iio_priv(indio_dev);
81 int ret;
82
83 switch (mask) {
84 case IIO_CHAN_INFO_RAW:
85 ret = si7005_read_measurement(data, chan->type == IIO_TEMP);
86 if (ret < 0)
87 return ret;
88 *val = ret;
89 return IIO_VAL_INT;
90 case IIO_CHAN_INFO_SCALE:
91 if (chan->type == IIO_TEMP) {
92 *val = 7;
93 *val2 = 812500;
94 } else {
95 *val = 3;
96 *val2 = 906250;
97 }
98 return IIO_VAL_INT_PLUS_MICRO;
99 case IIO_CHAN_INFO_OFFSET:
100 if (chan->type == IIO_TEMP)
101 *val = -50 * 32 * 4;
102 else
103 *val = -24 * 16 * 16;
104 return IIO_VAL_INT;
105 default:
106 break;
107 }
108
109 return -EINVAL;
110}
111
112static const struct iio_chan_spec si7005_channels[] = {
113 {
114 .type = IIO_HUMIDITYRELATIVE,
115 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
116 BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET),
117 },
118 {
119 .type = IIO_TEMP,
120 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
121 BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET),
122 }
123};
124
125static const struct iio_info si7005_info = {
126 .read_raw = si7005_read_raw,
127 .driver_module = THIS_MODULE,
128};
129
130static int si7005_probe(struct i2c_client *client,
131 const struct i2c_device_id *id)
132{
133 struct iio_dev *indio_dev;
134 struct si7005_data *data;
135 int ret;
136
137 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
138 return -EOPNOTSUPP;
139
140 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
141 if (!indio_dev)
142 return -ENOMEM;
143
144 data = iio_priv(indio_dev);
145 i2c_set_clientdata(client, indio_dev);
146 data->client = client;
147 mutex_init(&data->lock);
148
149 indio_dev->dev.parent = &client->dev;
150 indio_dev->name = dev_name(&client->dev);
151 indio_dev->modes = INDIO_DIRECT_MODE;
152 indio_dev->info = &si7005_info;
153
154 indio_dev->channels = si7005_channels;
155 indio_dev->num_channels = ARRAY_SIZE(si7005_channels);
156
157 ret = i2c_smbus_read_byte_data(client, SI7005_ID);
158 if (ret < 0)
159 return ret;
160 if (ret != SI7005_ID_7005 && ret != SI7005_ID_7015)
161 return -ENODEV;
162
163 ret = i2c_smbus_read_byte_data(client, SI7005_CONFIG);
164 if (ret < 0)
165 return ret;
166 data->config = ret;
167
168 return devm_iio_device_register(&client->dev, indio_dev);
169}
170
171static const struct i2c_device_id si7005_id[] = {
172 { "si7005", 0 },
173 { "th02", 0 },
174 { }
175};
176MODULE_DEVICE_TABLE(i2c, si7005_id);
177
178static struct i2c_driver si7005_driver = {
179 .driver = {
180 .name = "si7005",
181 },
182 .probe = si7005_probe,
183 .id_table = si7005_id,
184};
185module_i2c_driver(si7005_driver);
186
187MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
188MODULE_DESCRIPTION("Silabs Si7005 humidity and temperature sensor driver");
189MODULE_LICENSE("GPL");
190
