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 | |
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, value: val); |
89 | } |
90 | |
91 | static void al3320a_set_pwr_off(void *_data) |
92 | { |
93 | struct al3320a_data *data = _data; |
94 | |
95 | al3320a_set_pwr(client: data->client, pwr: false); |
96 | } |
97 | |
98 | static int al3320a_init(struct al3320a_data *data) |
99 | { |
100 | int ret; |
101 | |
102 | ret = al3320a_set_pwr(client: data->client, pwr: true); |
103 | |
104 | if (ret < 0) |
105 | return ret; |
106 | |
107 | ret = i2c_smbus_write_byte_data(client: 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(client: 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(client: data->client, AL3320A_REG_WAIT, |
119 | AL3320A_DEFAULT_WAIT_TIME); |
120 | if (ret < 0) |
121 | return ret; |
122 | |
123 | return 0; |
124 | } |
125 | |
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(client: 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(client: 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 | |
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(client: 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 | |
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(parent: &client->dev, sizeof_priv: sizeof(*data)); |
197 | if (!indio_dev) |
198 | return -ENOMEM; |
199 | |
200 | data = iio_priv(indio_dev); |
201 | i2c_set_clientdata(client, data: 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 | |
225 | static int al3320a_suspend(struct device *dev) |
226 | { |
227 | return al3320a_set_pwr(to_i2c_client(dev), pwr: false); |
228 | } |
229 | |
230 | static int al3320a_resume(struct device *dev) |
231 | { |
232 | return al3320a_set_pwr(to_i2c_client(dev), pwr: 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" , 0}, |
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 | |