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/of.h>
19#include <linux/mod_devicetable.h>
20
21#include <linux/iio/iio.h>
22#include <linux/iio/sysfs.h>
23
24#define AL3320A_DRV_NAME "al3320a"
25
26#define AL3320A_REG_CONFIG 0x00
27#define AL3320A_REG_STATUS 0x01
28#define AL3320A_REG_INT 0x02
29#define AL3320A_REG_WAIT 0x06
30#define AL3320A_REG_CONFIG_RANGE 0x07
31#define AL3320A_REG_PERSIST 0x08
32#define AL3320A_REG_MEAN_TIME 0x09
33#define AL3320A_REG_ADUMMY 0x0A
34#define AL3320A_REG_DATA_LOW 0x22
35
36#define AL3320A_REG_LOW_THRESH_LOW 0x30
37#define AL3320A_REG_LOW_THRESH_HIGH 0x31
38#define AL3320A_REG_HIGH_THRESH_LOW 0x32
39#define AL3320A_REG_HIGH_THRESH_HIGH 0x33
40
41#define AL3320A_CONFIG_DISABLE 0x00
42#define AL3320A_CONFIG_ENABLE 0x01
43
44#define AL3320A_GAIN_MASK GENMASK(2, 1)
45
46/* chip params default values */
47#define AL3320A_DEFAULT_MEAN_TIME 4
48#define AL3320A_DEFAULT_WAIT_TIME 0 /* no waiting */
49
50#define AL3320A_SCALE_AVAILABLE "0.512 0.128 0.032 0.01"
51
52enum al3320a_range {
53 AL3320A_RANGE_1, /* 33.28 Klx */
54 AL3320A_RANGE_2, /* 8.32 Klx */
55 AL3320A_RANGE_3, /* 2.08 Klx */
56 AL3320A_RANGE_4 /* 0.65 Klx */
57};
58
59static const int al3320a_scales[][2] = {
60 {0, 512000}, {0, 128000}, {0, 32000}, {0, 10000}
61};
62
63struct al3320a_data {
64 struct i2c_client *client;
65};
66
67static const struct iio_chan_spec al3320a_channels[] = {
68 {
69 .type = IIO_LIGHT,
70 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
71 BIT(IIO_CHAN_INFO_SCALE),
72 }
73};
74
75static IIO_CONST_ATTR(in_illuminance_scale_available, AL3320A_SCALE_AVAILABLE);
76
77static struct attribute *al3320a_attributes[] = {
78 &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
79 NULL,
80};
81
82static const struct attribute_group al3320a_attribute_group = {
83 .attrs = al3320a_attributes,
84};
85
86static int al3320a_set_pwr(struct i2c_client *client, bool pwr)
87{
88 u8 val = pwr ? AL3320A_CONFIG_ENABLE : AL3320A_CONFIG_DISABLE;
89 return i2c_smbus_write_byte_data(client, AL3320A_REG_CONFIG, value: val);
90}
91
92static void al3320a_set_pwr_off(void *_data)
93{
94 struct al3320a_data *data = _data;
95
96 al3320a_set_pwr(client: data->client, pwr: false);
97}
98
99static int al3320a_init(struct al3320a_data *data)
100{
101 int ret;
102
103 ret = al3320a_set_pwr(client: data->client, pwr: true);
104
105 if (ret < 0)
106 return ret;
107
108 ret = i2c_smbus_write_byte_data(client: data->client, AL3320A_REG_CONFIG_RANGE,
109 FIELD_PREP(AL3320A_GAIN_MASK,
110 AL3320A_RANGE_3));
111 if (ret < 0)
112 return ret;
113
114 ret = i2c_smbus_write_byte_data(client: data->client, AL3320A_REG_MEAN_TIME,
115 AL3320A_DEFAULT_MEAN_TIME);
116 if (ret < 0)
117 return ret;
118
119 ret = i2c_smbus_write_byte_data(client: data->client, AL3320A_REG_WAIT,
120 AL3320A_DEFAULT_WAIT_TIME);
121 if (ret < 0)
122 return ret;
123
124 return 0;
125}
126
127static int al3320a_read_raw(struct iio_dev *indio_dev,
128 struct iio_chan_spec const *chan, int *val,
129 int *val2, long mask)
130{
131 struct al3320a_data *data = iio_priv(indio_dev);
132 int ret;
133
134 switch (mask) {
135 case IIO_CHAN_INFO_RAW:
136 /*
137 * ALS ADC value is stored in two adjacent registers:
138 * - low byte of output is stored at AL3320A_REG_DATA_LOW
139 * - high byte of output is stored at AL3320A_REG_DATA_LOW + 1
140 */
141 ret = i2c_smbus_read_word_data(client: data->client,
142 AL3320A_REG_DATA_LOW);
143 if (ret < 0)
144 return ret;
145 *val = ret;
146 return IIO_VAL_INT;
147 case IIO_CHAN_INFO_SCALE:
148 ret = i2c_smbus_read_byte_data(client: data->client,
149 AL3320A_REG_CONFIG_RANGE);
150 if (ret < 0)
151 return ret;
152
153 ret = FIELD_GET(AL3320A_GAIN_MASK, ret);
154 *val = al3320a_scales[ret][0];
155 *val2 = al3320a_scales[ret][1];
156
157 return IIO_VAL_INT_PLUS_MICRO;
158 }
159 return -EINVAL;
160}
161
162static int al3320a_write_raw(struct iio_dev *indio_dev,
163 struct iio_chan_spec const *chan, int val,
164 int val2, long mask)
165{
166 struct al3320a_data *data = iio_priv(indio_dev);
167 int i;
168
169 switch (mask) {
170 case IIO_CHAN_INFO_SCALE:
171 for (i = 0; i < ARRAY_SIZE(al3320a_scales); i++) {
172 if (val != al3320a_scales[i][0] ||
173 val2 != al3320a_scales[i][1])
174 continue;
175
176 return i2c_smbus_write_byte_data(client: data->client,
177 AL3320A_REG_CONFIG_RANGE,
178 FIELD_PREP(AL3320A_GAIN_MASK, i));
179 }
180 break;
181 }
182 return -EINVAL;
183}
184
185static const struct iio_info al3320a_info = {
186 .read_raw = al3320a_read_raw,
187 .write_raw = al3320a_write_raw,
188 .attrs = &al3320a_attribute_group,
189};
190
191static int al3320a_probe(struct i2c_client *client)
192{
193 struct al3320a_data *data;
194 struct iio_dev *indio_dev;
195 int ret;
196
197 indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*data));
198 if (!indio_dev)
199 return -ENOMEM;
200
201 data = iio_priv(indio_dev);
202 i2c_set_clientdata(client, data: indio_dev);
203 data->client = client;
204
205 indio_dev->info = &al3320a_info;
206 indio_dev->name = AL3320A_DRV_NAME;
207 indio_dev->channels = al3320a_channels;
208 indio_dev->num_channels = ARRAY_SIZE(al3320a_channels);
209 indio_dev->modes = INDIO_DIRECT_MODE;
210
211 ret = al3320a_init(data);
212 if (ret < 0) {
213 dev_err(&client->dev, "al3320a chip init failed\n");
214 return ret;
215 }
216
217 ret = devm_add_action_or_reset(&client->dev,
218 al3320a_set_pwr_off,
219 data);
220 if (ret < 0)
221 return ret;
222
223 return devm_iio_device_register(&client->dev, indio_dev);
224}
225
226static int al3320a_suspend(struct device *dev)
227{
228 return al3320a_set_pwr(to_i2c_client(dev), pwr: false);
229}
230
231static int al3320a_resume(struct device *dev)
232{
233 return al3320a_set_pwr(to_i2c_client(dev), pwr: true);
234}
235
236static DEFINE_SIMPLE_DEV_PM_OPS(al3320a_pm_ops, al3320a_suspend,
237 al3320a_resume);
238
239static const struct i2c_device_id al3320a_id[] = {
240 {"al3320a", 0},
241 {}
242};
243MODULE_DEVICE_TABLE(i2c, al3320a_id);
244
245static const struct of_device_id al3320a_of_match[] = {
246 { .compatible = "dynaimage,al3320a", },
247 {},
248};
249MODULE_DEVICE_TABLE(of, al3320a_of_match);
250
251static const struct acpi_device_id al3320a_acpi_match[] = {
252 {"CALS0001"},
253 { },
254};
255MODULE_DEVICE_TABLE(acpi, al3320a_acpi_match);
256
257static struct i2c_driver al3320a_driver = {
258 .driver = {
259 .name = AL3320A_DRV_NAME,
260 .of_match_table = al3320a_of_match,
261 .pm = pm_sleep_ptr(&al3320a_pm_ops),
262 .acpi_match_table = al3320a_acpi_match,
263 },
264 .probe = al3320a_probe,
265 .id_table = al3320a_id,
266};
267
268module_i2c_driver(al3320a_driver);
269
270MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
271MODULE_DESCRIPTION("AL3320A Ambient Light Sensor driver");
272MODULE_LICENSE("GPL v2");
273

source code of linux/drivers/iio/light/al3320a.c