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/regmap.h>
21 #include <linux/mod_devicetable.h>
22
23 #include <linux/iio/iio.h>
24 #include <linux/iio/sysfs.h>
25
26 #define AL3010_REG_SYSTEM 0x00
27 #define AL3010_REG_DATA_LOW 0x0c
28 #define AL3010_REG_CONFIG 0x10
29
30 #define AL3010_CONFIG_DISABLE 0x00
31 #define AL3010_CONFIG_ENABLE 0x01
32
33 #define AL3010_GAIN_MASK GENMASK(6,4)
34
35 #define AL3010_SCALE_AVAILABLE "1.1872 0.2968 0.0742 0.018"
36
37 enum al3xxxx_range {
38 AL3XXX_RANGE_1, /* 77806 lx */
39 AL3XXX_RANGE_2, /* 19542 lx */
40 AL3XXX_RANGE_3, /* 4863 lx */
41 AL3XXX_RANGE_4 /* 1216 lx */
42 };
43
44 static const int al3010_scales[][2] = {
45 {0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600}
46 };
47
48 static const struct regmap_config al3010_regmap_config = {
49 .reg_bits = 8,
50 .val_bits = 8,
51 .max_register = AL3010_REG_CONFIG,
52 };
53
54 struct al3010_data {
55 struct regmap *regmap;
56 };
57
58 static const struct iio_chan_spec al3010_channels[] = {
59 {
60 .type = IIO_LIGHT,
61 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
62 BIT(IIO_CHAN_INFO_SCALE),
63 }
64 };
65
66 static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE);
67
68 static struct attribute *al3010_attributes[] = {
69 &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
70 NULL,
71 };
72
73 static const struct attribute_group al3010_attribute_group = {
74 .attrs = al3010_attributes,
75 };
76
al3010_set_pwr_on(struct al3010_data * data)77 static int al3010_set_pwr_on(struct al3010_data *data)
78 {
79 return regmap_write(data->regmap, AL3010_REG_SYSTEM, AL3010_CONFIG_ENABLE);
80 }
81
al3010_set_pwr_off(void * _data)82 static void al3010_set_pwr_off(void *_data)
83 {
84 struct al3010_data *data = _data;
85 struct device *dev = regmap_get_device(data->regmap);
86 int ret;
87
88 ret = regmap_write(data->regmap, AL3010_REG_SYSTEM, AL3010_CONFIG_DISABLE);
89 if (ret)
90 dev_err(dev, "failed to write system register\n");
91 }
92
al3010_init(struct al3010_data * data)93 static int al3010_init(struct al3010_data *data)
94 {
95 struct device *dev = regmap_get_device(data->regmap);
96 int ret;
97
98 ret = al3010_set_pwr_on(data);
99 if (ret)
100 return ret;
101
102 ret = devm_add_action_or_reset(dev, al3010_set_pwr_off, data);
103 if (ret)
104 return ret;
105 return regmap_write(data->regmap, AL3010_REG_CONFIG,
106 FIELD_PREP(AL3010_GAIN_MASK, AL3XXX_RANGE_3));
107 }
108
al3010_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)109 static int al3010_read_raw(struct iio_dev *indio_dev,
110 struct iio_chan_spec const *chan, int *val,
111 int *val2, long mask)
112 {
113 struct al3010_data *data = iio_priv(indio_dev);
114 int ret, gain, raw;
115
116 switch (mask) {
117 case IIO_CHAN_INFO_RAW:
118 /*
119 * ALS ADC value is stored in two adjacent registers:
120 * - low byte of output is stored at AL3010_REG_DATA_LOW
121 * - high byte of output is stored at AL3010_REG_DATA_LOW + 1
122 */
123 ret = regmap_read(data->regmap, AL3010_REG_DATA_LOW, &raw);
124 if (ret)
125 return ret;
126
127 *val = raw;
128
129 return IIO_VAL_INT;
130 case IIO_CHAN_INFO_SCALE:
131 ret = regmap_read(data->regmap, AL3010_REG_CONFIG, &gain);
132 if (ret)
133 return ret;
134
135 gain = FIELD_GET(AL3010_GAIN_MASK, gain);
136 *val = al3010_scales[gain][0];
137 *val2 = al3010_scales[gain][1];
138
139 return IIO_VAL_INT_PLUS_MICRO;
140 }
141 return -EINVAL;
142 }
143
al3010_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)144 static int al3010_write_raw(struct iio_dev *indio_dev,
145 struct iio_chan_spec const *chan, int val,
146 int val2, long mask)
147 {
148 struct al3010_data *data = iio_priv(indio_dev);
149 unsigned int i;
150
151 switch (mask) {
152 case IIO_CHAN_INFO_SCALE:
153 for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) {
154 if (val != al3010_scales[i][0] ||
155 val2 != al3010_scales[i][1])
156 continue;
157
158 return regmap_write(data->regmap, AL3010_REG_CONFIG,
159 FIELD_PREP(AL3010_GAIN_MASK, i));
160 }
161 break;
162 }
163 return -EINVAL;
164 }
165
166 static const struct iio_info al3010_info = {
167 .read_raw = al3010_read_raw,
168 .write_raw = al3010_write_raw,
169 .attrs = &al3010_attribute_group,
170 };
171
al3010_probe(struct i2c_client * client)172 static int al3010_probe(struct i2c_client *client)
173 {
174 struct al3010_data *data;
175 struct device *dev = &client->dev;
176 struct iio_dev *indio_dev;
177 int ret;
178
179 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
180 if (!indio_dev)
181 return -ENOMEM;
182
183 data = iio_priv(indio_dev);
184 i2c_set_clientdata(client, indio_dev);
185 data->regmap = devm_regmap_init_i2c(client, &al3010_regmap_config);
186 if (IS_ERR(data->regmap))
187 return dev_err_probe(dev, PTR_ERR(data->regmap),
188 "cannot allocate regmap\n");
189
190 indio_dev->info = &al3010_info;
191 indio_dev->name = "al3010";
192 indio_dev->channels = al3010_channels;
193 indio_dev->num_channels = ARRAY_SIZE(al3010_channels);
194 indio_dev->modes = INDIO_DIRECT_MODE;
195
196 ret = al3010_init(data);
197 if (ret)
198 return dev_err_probe(dev, ret, "failed to init ALS\n");
199
200 return devm_iio_device_register(dev, indio_dev);
201 }
202
al3010_suspend(struct device * dev)203 static int al3010_suspend(struct device *dev)
204 {
205 struct al3010_data *data = iio_priv(dev_get_drvdata(dev));
206
207 al3010_set_pwr_off(data);
208 return 0;
209 }
210
al3010_resume(struct device * dev)211 static int al3010_resume(struct device *dev)
212 {
213 struct al3010_data *data = iio_priv(dev_get_drvdata(dev));
214
215 return al3010_set_pwr_on(data);
216 }
217
218 static DEFINE_SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume);
219
220 static const struct i2c_device_id al3010_id[] = {
221 {"al3010", },
222 { }
223 };
224 MODULE_DEVICE_TABLE(i2c, al3010_id);
225
226 static const struct of_device_id al3010_of_match[] = {
227 { .compatible = "dynaimage,al3010", },
228 { }
229 };
230 MODULE_DEVICE_TABLE(of, al3010_of_match);
231
232 static struct i2c_driver al3010_driver = {
233 .driver = {
234 .name = "al3010",
235 .of_match_table = al3010_of_match,
236 .pm = pm_sleep_ptr(&al3010_pm_ops),
237 },
238 .probe = al3010_probe,
239 .id_table = al3010_id,
240 };
241 module_i2c_driver(al3010_driver);
242
243 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
244 MODULE_AUTHOR("David Heidelberg <david@ixit.cz>");
245 MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver");
246 MODULE_LICENSE("GPL v2");
247