1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * veml6070.c - Support for Vishay VEML6070 UV A light sensor |
4 | * |
5 | * Copyright 2016 Peter Meerwald-Stadler <pmeerw@pmeerw.net> |
6 | * |
7 | * IIO driver for VEML6070 (7-bit I2C slave addresses 0x38 and 0x39) |
8 | * |
9 | * TODO: integration time, ACK signal |
10 | */ |
11 | |
12 | #include <linux/module.h> |
13 | #include <linux/i2c.h> |
14 | #include <linux/mutex.h> |
15 | #include <linux/err.h> |
16 | #include <linux/delay.h> |
17 | |
18 | #include <linux/iio/iio.h> |
19 | #include <linux/iio/sysfs.h> |
20 | |
21 | #define VEML6070_DRV_NAME "veml6070" |
22 | |
23 | #define VEML6070_ADDR_CONFIG_DATA_MSB 0x38 /* read: MSB data, write: config */ |
24 | #define VEML6070_ADDR_DATA_LSB 0x39 /* LSB data */ |
25 | |
26 | #define VEML6070_COMMAND_ACK BIT(5) /* raise interrupt when over threshold */ |
27 | #define VEML6070_COMMAND_IT GENMASK(3, 2) /* bit mask integration time */ |
28 | #define VEML6070_COMMAND_RSRVD BIT(1) /* reserved, set to 1 */ |
29 | #define VEML6070_COMMAND_SD BIT(0) /* shutdown mode when set */ |
30 | |
31 | #define VEML6070_IT_10 0x04 /* integration time 1x */ |
32 | |
33 | struct veml6070_data { |
34 | struct i2c_client *client1; |
35 | struct i2c_client *client2; |
36 | u8 config; |
37 | struct mutex lock; |
38 | }; |
39 | |
40 | static int veml6070_read(struct veml6070_data *data) |
41 | { |
42 | int ret; |
43 | u8 msb, lsb; |
44 | |
45 | mutex_lock(&data->lock); |
46 | |
47 | /* disable shutdown */ |
48 | ret = i2c_smbus_write_byte(client: data->client1, |
49 | value: data->config & ~VEML6070_COMMAND_SD); |
50 | if (ret < 0) |
51 | goto out; |
52 | |
53 | msleep(msecs: 125 + 10); /* measurement takes up to 125 ms for IT 1x */ |
54 | |
55 | ret = i2c_smbus_read_byte(client: data->client2); /* read MSB, address 0x39 */ |
56 | if (ret < 0) |
57 | goto out; |
58 | msb = ret; |
59 | |
60 | ret = i2c_smbus_read_byte(client: data->client1); /* read LSB, address 0x38 */ |
61 | if (ret < 0) |
62 | goto out; |
63 | lsb = ret; |
64 | |
65 | /* shutdown again */ |
66 | ret = i2c_smbus_write_byte(client: data->client1, value: data->config); |
67 | if (ret < 0) |
68 | goto out; |
69 | |
70 | ret = (msb << 8) | lsb; |
71 | |
72 | out: |
73 | mutex_unlock(lock: &data->lock); |
74 | return ret; |
75 | } |
76 | |
77 | static const struct iio_chan_spec veml6070_channels[] = { |
78 | { |
79 | .type = IIO_INTENSITY, |
80 | .modified = 1, |
81 | .channel2 = IIO_MOD_LIGHT_UV, |
82 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
83 | }, |
84 | { |
85 | .type = IIO_UVINDEX, |
86 | .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), |
87 | } |
88 | }; |
89 | |
90 | static int veml6070_to_uv_index(unsigned val) |
91 | { |
92 | /* |
93 | * conversion of raw UV intensity values to UV index depends on |
94 | * integration time (IT) and value of the resistor connected to |
95 | * the RSET pin (default: 270 KOhm) |
96 | */ |
97 | unsigned uvi[11] = { |
98 | 187, 373, 560, /* low */ |
99 | 746, 933, 1120, /* moderate */ |
100 | 1308, 1494, /* high */ |
101 | 1681, 1868, 2054}; /* very high */ |
102 | int i; |
103 | |
104 | for (i = 0; i < ARRAY_SIZE(uvi); i++) |
105 | if (val <= uvi[i]) |
106 | return i; |
107 | |
108 | return 11; /* extreme */ |
109 | } |
110 | |
111 | static int veml6070_read_raw(struct iio_dev *indio_dev, |
112 | struct iio_chan_spec const *chan, |
113 | int *val, int *val2, long mask) |
114 | { |
115 | struct veml6070_data *data = iio_priv(indio_dev); |
116 | int ret; |
117 | |
118 | switch (mask) { |
119 | case IIO_CHAN_INFO_RAW: |
120 | case IIO_CHAN_INFO_PROCESSED: |
121 | ret = veml6070_read(data); |
122 | if (ret < 0) |
123 | return ret; |
124 | if (mask == IIO_CHAN_INFO_PROCESSED) |
125 | *val = veml6070_to_uv_index(val: ret); |
126 | else |
127 | *val = ret; |
128 | return IIO_VAL_INT; |
129 | default: |
130 | return -EINVAL; |
131 | } |
132 | } |
133 | |
134 | static const struct iio_info veml6070_info = { |
135 | .read_raw = veml6070_read_raw, |
136 | }; |
137 | |
138 | static int veml6070_probe(struct i2c_client *client) |
139 | { |
140 | struct veml6070_data *data; |
141 | struct iio_dev *indio_dev; |
142 | int ret; |
143 | |
144 | indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*data)); |
145 | if (!indio_dev) |
146 | return -ENOMEM; |
147 | |
148 | data = iio_priv(indio_dev); |
149 | i2c_set_clientdata(client, data: indio_dev); |
150 | data->client1 = client; |
151 | mutex_init(&data->lock); |
152 | |
153 | indio_dev->info = &veml6070_info; |
154 | indio_dev->channels = veml6070_channels; |
155 | indio_dev->num_channels = ARRAY_SIZE(veml6070_channels); |
156 | indio_dev->name = VEML6070_DRV_NAME; |
157 | indio_dev->modes = INDIO_DIRECT_MODE; |
158 | |
159 | data->client2 = i2c_new_dummy_device(adapter: client->adapter, VEML6070_ADDR_DATA_LSB); |
160 | if (IS_ERR(ptr: data->client2)) { |
161 | dev_err(&client->dev, "i2c device for second chip address failed\n" ); |
162 | return PTR_ERR(ptr: data->client2); |
163 | } |
164 | |
165 | data->config = VEML6070_IT_10 | VEML6070_COMMAND_RSRVD | |
166 | VEML6070_COMMAND_SD; |
167 | ret = i2c_smbus_write_byte(client: data->client1, value: data->config); |
168 | if (ret < 0) |
169 | goto fail; |
170 | |
171 | ret = iio_device_register(indio_dev); |
172 | if (ret < 0) |
173 | goto fail; |
174 | |
175 | return ret; |
176 | |
177 | fail: |
178 | i2c_unregister_device(client: data->client2); |
179 | return ret; |
180 | } |
181 | |
182 | static void veml6070_remove(struct i2c_client *client) |
183 | { |
184 | struct iio_dev *indio_dev = i2c_get_clientdata(client); |
185 | struct veml6070_data *data = iio_priv(indio_dev); |
186 | |
187 | iio_device_unregister(indio_dev); |
188 | i2c_unregister_device(client: data->client2); |
189 | } |
190 | |
191 | static const struct i2c_device_id veml6070_id[] = { |
192 | { "veml6070" , 0 }, |
193 | { } |
194 | }; |
195 | MODULE_DEVICE_TABLE(i2c, veml6070_id); |
196 | |
197 | static struct i2c_driver veml6070_driver = { |
198 | .driver = { |
199 | .name = VEML6070_DRV_NAME, |
200 | }, |
201 | .probe = veml6070_probe, |
202 | .remove = veml6070_remove, |
203 | .id_table = veml6070_id, |
204 | }; |
205 | |
206 | module_i2c_driver(veml6070_driver); |
207 | |
208 | MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>" ); |
209 | MODULE_DESCRIPTION("Vishay VEML6070 UV A light sensor driver" ); |
210 | MODULE_LICENSE("GPL" ); |
211 | |