1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AL3010 - Dyna Image Ambient Light Sensor
4 *
5 * Copyright (c) 2014, Intel Corporation.
6 * Copyright (c) 2016, Dyna-Image Corp.
7 * Copyright (c) 2020, David Heidelberg, Michał Mirosław, Dmitry Osipenko
8 *
9 * IIO driver for AL3010 (7-bit I2C slave address 0x1C).
10 *
11 * TODO: interrupt support, thresholds
12 * When the driver will get support for interrupt handling, then interrupt
13 * will need to be disabled before turning sensor OFF in order to avoid
14 * potential races with the interrupt handling.
15 */
16
17 #include <linux/bitfield.h>
18 #include <linux/i2c.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
24
25 #define AL3010_DRV_NAME "al3010"
26
27 #define AL3010_REG_SYSTEM 0x00
28 #define AL3010_REG_DATA_LOW 0x0c
29 #define AL3010_REG_CONFIG 0x10
30
31 #define AL3010_CONFIG_DISABLE 0x00
32 #define AL3010_CONFIG_ENABLE 0x01
33
34 #define AL3010_GAIN_MASK GENMASK(6,4)
35
36 #define AL3010_SCALE_AVAILABLE "1.1872 0.2968 0.0742 0.018"
37
38 enum al3xxxx_range {
39 AL3XXX_RANGE_1, /* 77806 lx */
40 AL3XXX_RANGE_2, /* 19542 lx */
41 AL3XXX_RANGE_3, /* 4863 lx */
42 AL3XXX_RANGE_4 /* 1216 lx */
43 };
44
45 static const int al3010_scales[][2] = {
46 {0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600}
47 };
48
49 struct al3010_data {
50 struct i2c_client *client;
51 };
52
53 static const struct iio_chan_spec al3010_channels[] = {
54 {
55 .type = IIO_LIGHT,
56 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
57 BIT(IIO_CHAN_INFO_SCALE),
58 }
59 };
60
61 static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE);
62
63 static struct attribute *al3010_attributes[] = {
64 &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
65 NULL,
66 };
67
68 static const struct attribute_group al3010_attribute_group = {
69 .attrs = al3010_attributes,
70 };
71
al3010_set_pwr(struct i2c_client * client,bool pwr)72 static int al3010_set_pwr(struct i2c_client *client, bool pwr)
73 {
74 u8 val = pwr ? AL3010_CONFIG_ENABLE : AL3010_CONFIG_DISABLE;
75 return i2c_smbus_write_byte_data(client, AL3010_REG_SYSTEM, val);
76 }
77
al3010_set_pwr_off(void * _data)78 static void al3010_set_pwr_off(void *_data)
79 {
80 struct al3010_data *data = _data;
81
82 al3010_set_pwr(data->client, false);
83 }
84
al3010_init(struct al3010_data * data)85 static int al3010_init(struct al3010_data *data)
86 {
87 int ret;
88
89 ret = al3010_set_pwr(data->client, true);
90
91 if (ret < 0)
92 return ret;
93
94 ret = i2c_smbus_write_byte_data(data->client, AL3010_REG_CONFIG,
95 FIELD_PREP(AL3010_GAIN_MASK,
96 AL3XXX_RANGE_3));
97 if (ret < 0)
98 return ret;
99
100 return 0;
101 }
102
al3010_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)103 static int al3010_read_raw(struct iio_dev *indio_dev,
104 struct iio_chan_spec const *chan, int *val,
105 int *val2, long mask)
106 {
107 struct al3010_data *data = iio_priv(indio_dev);
108 int ret;
109
110 switch (mask) {
111 case IIO_CHAN_INFO_RAW:
112 /*
113 * ALS ADC value is stored in two adjacent registers:
114 * - low byte of output is stored at AL3010_REG_DATA_LOW
115 * - high byte of output is stored at AL3010_REG_DATA_LOW + 1
116 */
117 ret = i2c_smbus_read_word_data(data->client,
118 AL3010_REG_DATA_LOW);
119 if (ret < 0)
120 return ret;
121 *val = ret;
122 return IIO_VAL_INT;
123 case IIO_CHAN_INFO_SCALE:
124 ret = i2c_smbus_read_byte_data(data->client,
125 AL3010_REG_CONFIG);
126 if (ret < 0)
127 return ret;
128
129 ret = FIELD_GET(AL3010_GAIN_MASK, ret);
130 *val = al3010_scales[ret][0];
131 *val2 = al3010_scales[ret][1];
132
133 return IIO_VAL_INT_PLUS_MICRO;
134 }
135 return -EINVAL;
136 }
137
al3010_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)138 static int al3010_write_raw(struct iio_dev *indio_dev,
139 struct iio_chan_spec const *chan, int val,
140 int val2, long mask)
141 {
142 struct al3010_data *data = iio_priv(indio_dev);
143 int i;
144
145 switch (mask) {
146 case IIO_CHAN_INFO_SCALE:
147 for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) {
148 if (val != al3010_scales[i][0] ||
149 val2 != al3010_scales[i][1])
150 continue;
151
152 return i2c_smbus_write_byte_data(data->client,
153 AL3010_REG_CONFIG,
154 FIELD_PREP(AL3010_GAIN_MASK, i));
155 }
156 break;
157 }
158 return -EINVAL;
159 }
160
161 static const struct iio_info al3010_info = {
162 .read_raw = al3010_read_raw,
163 .write_raw = al3010_write_raw,
164 .attrs = &al3010_attribute_group,
165 };
166
al3010_probe(struct i2c_client * client)167 static int al3010_probe(struct i2c_client *client)
168 {
169 struct al3010_data *data;
170 struct iio_dev *indio_dev;
171 int ret;
172
173 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
174 if (!indio_dev)
175 return -ENOMEM;
176
177 data = iio_priv(indio_dev);
178 i2c_set_clientdata(client, indio_dev);
179 data->client = client;
180
181 indio_dev->info = &al3010_info;
182 indio_dev->name = AL3010_DRV_NAME;
183 indio_dev->channels = al3010_channels;
184 indio_dev->num_channels = ARRAY_SIZE(al3010_channels);
185 indio_dev->modes = INDIO_DIRECT_MODE;
186
187 ret = al3010_init(data);
188 if (ret < 0) {
189 dev_err(&client->dev, "al3010 chip init failed\n");
190 return ret;
191 }
192
193 ret = devm_add_action_or_reset(&client->dev,
194 al3010_set_pwr_off,
195 data);
196 if (ret < 0)
197 return ret;
198
199 return devm_iio_device_register(&client->dev, indio_dev);
200 }
201
al3010_suspend(struct device * dev)202 static int al3010_suspend(struct device *dev)
203 {
204 return al3010_set_pwr(to_i2c_client(dev), false);
205 }
206
al3010_resume(struct device * dev)207 static int al3010_resume(struct device *dev)
208 {
209 return al3010_set_pwr(to_i2c_client(dev), true);
210 }
211
212 static DEFINE_SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume);
213
214 static const struct i2c_device_id al3010_id[] = {
215 {"al3010", },
216 {}
217 };
218 MODULE_DEVICE_TABLE(i2c, al3010_id);
219
220 static const struct of_device_id al3010_of_match[] = {
221 { .compatible = "dynaimage,al3010", },
222 {},
223 };
224 MODULE_DEVICE_TABLE(of, al3010_of_match);
225
226 static struct i2c_driver al3010_driver = {
227 .driver = {
228 .name = AL3010_DRV_NAME,
229 .of_match_table = al3010_of_match,
230 .pm = pm_sleep_ptr(&al3010_pm_ops),
231 },
232 .probe = al3010_probe,
233 .id_table = al3010_id,
234 };
235 module_i2c_driver(al3010_driver);
236
237 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
238 MODULE_AUTHOR("David Heidelberg <david@ixit.cz>");
239 MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver");
240 MODULE_LICENSE("GPL v2");
241