1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AL3320A - Dyna Image Ambient Light Sensor
4 *
5 * Copyright (c) 2014, Intel Corporation.
6 *
7 * IIO driver for AL3320A (7-bit I2C slave address 0x1C).
8 *
9 * TODO: interrupt support, thresholds
10 * When the driver will get support for interrupt handling, then interrupt
11 * will need to be disabled before turning sensor OFF in order to avoid
12 * potential races with the interrupt handling.
13 */
14
15 #include <linux/bitfield.h>
16 #include <linux/i2c.h>
17 #include <linux/module.h>
18 #include <linux/mod_devicetable.h>
19
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22
23 #define AL3320A_DRV_NAME "al3320a"
24
25 #define AL3320A_REG_CONFIG 0x00
26 #define AL3320A_REG_STATUS 0x01
27 #define AL3320A_REG_INT 0x02
28 #define AL3320A_REG_WAIT 0x06
29 #define AL3320A_REG_CONFIG_RANGE 0x07
30 #define AL3320A_REG_PERSIST 0x08
31 #define AL3320A_REG_MEAN_TIME 0x09
32 #define AL3320A_REG_ADUMMY 0x0A
33 #define AL3320A_REG_DATA_LOW 0x22
34
35 #define AL3320A_REG_LOW_THRESH_LOW 0x30
36 #define AL3320A_REG_LOW_THRESH_HIGH 0x31
37 #define AL3320A_REG_HIGH_THRESH_LOW 0x32
38 #define AL3320A_REG_HIGH_THRESH_HIGH 0x33
39
40 #define AL3320A_CONFIG_DISABLE 0x00
41 #define AL3320A_CONFIG_ENABLE 0x01
42
43 #define AL3320A_GAIN_MASK GENMASK(2, 1)
44
45 /* chip params default values */
46 #define AL3320A_DEFAULT_MEAN_TIME 4
47 #define AL3320A_DEFAULT_WAIT_TIME 0 /* no waiting */
48
49 #define AL3320A_SCALE_AVAILABLE "0.512 0.128 0.032 0.01"
50
51 enum al3320a_range {
52 AL3320A_RANGE_1, /* 33.28 Klx */
53 AL3320A_RANGE_2, /* 8.32 Klx */
54 AL3320A_RANGE_3, /* 2.08 Klx */
55 AL3320A_RANGE_4 /* 0.65 Klx */
56 };
57
58 static const int al3320a_scales[][2] = {
59 {0, 512000}, {0, 128000}, {0, 32000}, {0, 10000}
60 };
61
62 struct al3320a_data {
63 struct i2c_client *client;
64 };
65
66 static const struct iio_chan_spec al3320a_channels[] = {
67 {
68 .type = IIO_LIGHT,
69 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
70 BIT(IIO_CHAN_INFO_SCALE),
71 }
72 };
73
74 static IIO_CONST_ATTR(in_illuminance_scale_available, AL3320A_SCALE_AVAILABLE);
75
76 static struct attribute *al3320a_attributes[] = {
77 &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
78 NULL,
79 };
80
81 static const struct attribute_group al3320a_attribute_group = {
82 .attrs = al3320a_attributes,
83 };
84
al3320a_set_pwr(struct i2c_client * client,bool pwr)85 static int al3320a_set_pwr(struct i2c_client *client, bool pwr)
86 {
87 u8 val = pwr ? AL3320A_CONFIG_ENABLE : AL3320A_CONFIG_DISABLE;
88 return i2c_smbus_write_byte_data(client, AL3320A_REG_CONFIG, val);
89 }
90
al3320a_set_pwr_off(void * _data)91 static void al3320a_set_pwr_off(void *_data)
92 {
93 struct al3320a_data *data = _data;
94
95 al3320a_set_pwr(data->client, false);
96 }
97
al3320a_init(struct al3320a_data * data)98 static int al3320a_init(struct al3320a_data *data)
99 {
100 int ret;
101
102 ret = al3320a_set_pwr(data->client, true);
103
104 if (ret < 0)
105 return ret;
106
107 ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG_RANGE,
108 FIELD_PREP(AL3320A_GAIN_MASK,
109 AL3320A_RANGE_3));
110 if (ret < 0)
111 return ret;
112
113 ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_MEAN_TIME,
114 AL3320A_DEFAULT_MEAN_TIME);
115 if (ret < 0)
116 return ret;
117
118 ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_WAIT,
119 AL3320A_DEFAULT_WAIT_TIME);
120 if (ret < 0)
121 return ret;
122
123 return 0;
124 }
125
al3320a_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)126 static int al3320a_read_raw(struct iio_dev *indio_dev,
127 struct iio_chan_spec const *chan, int *val,
128 int *val2, long mask)
129 {
130 struct al3320a_data *data = iio_priv(indio_dev);
131 int ret;
132
133 switch (mask) {
134 case IIO_CHAN_INFO_RAW:
135 /*
136 * ALS ADC value is stored in two adjacent registers:
137 * - low byte of output is stored at AL3320A_REG_DATA_LOW
138 * - high byte of output is stored at AL3320A_REG_DATA_LOW + 1
139 */
140 ret = i2c_smbus_read_word_data(data->client,
141 AL3320A_REG_DATA_LOW);
142 if (ret < 0)
143 return ret;
144 *val = ret;
145 return IIO_VAL_INT;
146 case IIO_CHAN_INFO_SCALE:
147 ret = i2c_smbus_read_byte_data(data->client,
148 AL3320A_REG_CONFIG_RANGE);
149 if (ret < 0)
150 return ret;
151
152 ret = FIELD_GET(AL3320A_GAIN_MASK, ret);
153 *val = al3320a_scales[ret][0];
154 *val2 = al3320a_scales[ret][1];
155
156 return IIO_VAL_INT_PLUS_MICRO;
157 }
158 return -EINVAL;
159 }
160
al3320a_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)161 static int al3320a_write_raw(struct iio_dev *indio_dev,
162 struct iio_chan_spec const *chan, int val,
163 int val2, long mask)
164 {
165 struct al3320a_data *data = iio_priv(indio_dev);
166 int i;
167
168 switch (mask) {
169 case IIO_CHAN_INFO_SCALE:
170 for (i = 0; i < ARRAY_SIZE(al3320a_scales); i++) {
171 if (val != al3320a_scales[i][0] ||
172 val2 != al3320a_scales[i][1])
173 continue;
174
175 return i2c_smbus_write_byte_data(data->client,
176 AL3320A_REG_CONFIG_RANGE,
177 FIELD_PREP(AL3320A_GAIN_MASK, i));
178 }
179 break;
180 }
181 return -EINVAL;
182 }
183
184 static const struct iio_info al3320a_info = {
185 .read_raw = al3320a_read_raw,
186 .write_raw = al3320a_write_raw,
187 .attrs = &al3320a_attribute_group,
188 };
189
al3320a_probe(struct i2c_client * client)190 static int al3320a_probe(struct i2c_client *client)
191 {
192 struct al3320a_data *data;
193 struct iio_dev *indio_dev;
194 int ret;
195
196 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
197 if (!indio_dev)
198 return -ENOMEM;
199
200 data = iio_priv(indio_dev);
201 i2c_set_clientdata(client, indio_dev);
202 data->client = client;
203
204 indio_dev->info = &al3320a_info;
205 indio_dev->name = AL3320A_DRV_NAME;
206 indio_dev->channels = al3320a_channels;
207 indio_dev->num_channels = ARRAY_SIZE(al3320a_channels);
208 indio_dev->modes = INDIO_DIRECT_MODE;
209
210 ret = al3320a_init(data);
211 if (ret < 0) {
212 dev_err(&client->dev, "al3320a chip init failed\n");
213 return ret;
214 }
215
216 ret = devm_add_action_or_reset(&client->dev,
217 al3320a_set_pwr_off,
218 data);
219 if (ret < 0)
220 return ret;
221
222 return devm_iio_device_register(&client->dev, indio_dev);
223 }
224
al3320a_suspend(struct device * dev)225 static int al3320a_suspend(struct device *dev)
226 {
227 return al3320a_set_pwr(to_i2c_client(dev), false);
228 }
229
al3320a_resume(struct device * dev)230 static int al3320a_resume(struct device *dev)
231 {
232 return al3320a_set_pwr(to_i2c_client(dev), true);
233 }
234
235 static DEFINE_SIMPLE_DEV_PM_OPS(al3320a_pm_ops, al3320a_suspend,
236 al3320a_resume);
237
238 static const struct i2c_device_id al3320a_id[] = {
239 { "al3320a" },
240 {}
241 };
242 MODULE_DEVICE_TABLE(i2c, al3320a_id);
243
244 static const struct of_device_id al3320a_of_match[] = {
245 { .compatible = "dynaimage,al3320a", },
246 {},
247 };
248 MODULE_DEVICE_TABLE(of, al3320a_of_match);
249
250 static const struct acpi_device_id al3320a_acpi_match[] = {
251 {"CALS0001"},
252 { },
253 };
254 MODULE_DEVICE_TABLE(acpi, al3320a_acpi_match);
255
256 static struct i2c_driver al3320a_driver = {
257 .driver = {
258 .name = AL3320A_DRV_NAME,
259 .of_match_table = al3320a_of_match,
260 .pm = pm_sleep_ptr(&al3320a_pm_ops),
261 .acpi_match_table = al3320a_acpi_match,
262 },
263 .probe = al3320a_probe,
264 .id_table = al3320a_id,
265 };
266
267 module_i2c_driver(al3320a_driver);
268
269 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
270 MODULE_DESCRIPTION("AL3320A Ambient Light Sensor driver");
271 MODULE_LICENSE("GPL v2");
272