1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Support for ON Semiconductor NOA1305 ambient light sensor
4 *
5 * Copyright (C) 2016 Emcraft Systems
6 * Copyright (C) 2019 Collabora Ltd.
7 */
8
9 #include <linux/delay.h>
10 #include <linux/err.h>
11 #include <linux/i2c.h>
12 #include <linux/iio/iio.h>
13 #include <linux/iio/sysfs.h>
14 #include <linux/module.h>
15 #include <linux/regmap.h>
16 #include <linux/regulator/consumer.h>
17
18 #define NOA1305_REG_POWER_CONTROL 0x0
19 #define NOA1305_POWER_CONTROL_DOWN 0x00
20 #define NOA1305_POWER_CONTROL_ON 0x08
21 #define NOA1305_REG_RESET 0x1
22 #define NOA1305_RESET_RESET 0x10
23 #define NOA1305_REG_INTEGRATION_TIME 0x2
24 #define NOA1305_INTEGR_TIME_800MS 0x00
25 #define NOA1305_INTEGR_TIME_400MS 0x01
26 #define NOA1305_INTEGR_TIME_200MS 0x02
27 #define NOA1305_INTEGR_TIME_100MS 0x03
28 #define NOA1305_INTEGR_TIME_50MS 0x04
29 #define NOA1305_INTEGR_TIME_25MS 0x05
30 #define NOA1305_INTEGR_TIME_12_5MS 0x06
31 #define NOA1305_INTEGR_TIME_6_25MS 0x07
32 #define NOA1305_REG_INT_SELECT 0x3
33 #define NOA1305_INT_SEL_ACTIVE_HIGH 0x01
34 #define NOA1305_INT_SEL_ACTIVE_LOW 0x02
35 #define NOA1305_INT_SEL_INACTIVE 0x03
36 #define NOA1305_REG_INT_THRESH_LSB 0x4
37 #define NOA1305_REG_INT_THRESH_MSB 0x5
38 #define NOA1305_REG_ALS_DATA_LSB 0x6
39 #define NOA1305_REG_ALS_DATA_MSB 0x7
40 #define NOA1305_REG_DEVICE_ID_LSB 0x8
41 #define NOA1305_REG_DEVICE_ID_MSB 0x9
42
43 #define NOA1305_DEVICE_ID 0x0519
44 #define NOA1305_DRIVER_NAME "noa1305"
45
46 struct noa1305_priv {
47 struct i2c_client *client;
48 struct regmap *regmap;
49 };
50
noa1305_measure(struct noa1305_priv * priv)51 static int noa1305_measure(struct noa1305_priv *priv)
52 {
53 __le16 data;
54 int ret;
55
56 ret = regmap_bulk_read(priv->regmap, NOA1305_REG_ALS_DATA_LSB, &data,
57 2);
58 if (ret < 0)
59 return ret;
60
61 return le16_to_cpu(data);
62 }
63
noa1305_scale(struct noa1305_priv * priv,int * val,int * val2)64 static int noa1305_scale(struct noa1305_priv *priv, int *val, int *val2)
65 {
66 int data;
67 int ret;
68
69 ret = regmap_read(priv->regmap, NOA1305_REG_INTEGRATION_TIME, &data);
70 if (ret < 0)
71 return ret;
72
73 /*
74 * Lux = count / (<Integration Constant> * <Integration Time>)
75 *
76 * Integration Constant = 7.7
77 * Integration Time in Seconds
78 */
79 switch (data) {
80 case NOA1305_INTEGR_TIME_800MS:
81 *val = 100;
82 *val2 = 77 * 8;
83 break;
84 case NOA1305_INTEGR_TIME_400MS:
85 *val = 100;
86 *val2 = 77 * 4;
87 break;
88 case NOA1305_INTEGR_TIME_200MS:
89 *val = 100;
90 *val2 = 77 * 2;
91 break;
92 case NOA1305_INTEGR_TIME_100MS:
93 *val = 100;
94 *val2 = 77;
95 break;
96 case NOA1305_INTEGR_TIME_50MS:
97 *val = 1000;
98 *val2 = 77 * 5;
99 break;
100 case NOA1305_INTEGR_TIME_25MS:
101 *val = 10000;
102 *val2 = 77 * 25;
103 break;
104 case NOA1305_INTEGR_TIME_12_5MS:
105 *val = 100000;
106 *val2 = 77 * 125;
107 break;
108 case NOA1305_INTEGR_TIME_6_25MS:
109 *val = 1000000;
110 *val2 = 77 * 625;
111 break;
112 default:
113 return -EINVAL;
114 }
115
116 return IIO_VAL_FRACTIONAL;
117 }
118
119 static const struct iio_chan_spec noa1305_channels[] = {
120 {
121 .type = IIO_LIGHT,
122 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
123 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
124 }
125 };
126
noa1305_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)127 static int noa1305_read_raw(struct iio_dev *indio_dev,
128 struct iio_chan_spec const *chan,
129 int *val, int *val2, long mask)
130 {
131 int ret = -EINVAL;
132 struct noa1305_priv *priv = iio_priv(indio_dev);
133
134 switch (mask) {
135 case IIO_CHAN_INFO_RAW:
136 switch (chan->type) {
137 case IIO_LIGHT:
138 ret = noa1305_measure(priv);
139 if (ret < 0)
140 return ret;
141 *val = ret;
142 return IIO_VAL_INT;
143 default:
144 break;
145 }
146 break;
147 case IIO_CHAN_INFO_SCALE:
148 switch (chan->type) {
149 case IIO_LIGHT:
150 return noa1305_scale(priv, val, val2);
151 default:
152 break;
153 }
154 break;
155 default:
156 break;
157 }
158
159 return ret;
160 }
161
162 static const struct iio_info noa1305_info = {
163 .read_raw = noa1305_read_raw,
164 };
165
noa1305_writable_reg(struct device * dev,unsigned int reg)166 static bool noa1305_writable_reg(struct device *dev, unsigned int reg)
167 {
168 switch (reg) {
169 case NOA1305_REG_POWER_CONTROL:
170 case NOA1305_REG_RESET:
171 case NOA1305_REG_INTEGRATION_TIME:
172 case NOA1305_REG_INT_SELECT:
173 case NOA1305_REG_INT_THRESH_LSB:
174 case NOA1305_REG_INT_THRESH_MSB:
175 return true;
176 default:
177 return false;
178 }
179 }
180
181 static const struct regmap_config noa1305_regmap_config = {
182 .name = NOA1305_DRIVER_NAME,
183 .reg_bits = 8,
184 .val_bits = 8,
185 .max_register = NOA1305_REG_DEVICE_ID_MSB,
186 .writeable_reg = noa1305_writable_reg,
187 };
188
noa1305_probe(struct i2c_client * client)189 static int noa1305_probe(struct i2c_client *client)
190 {
191 struct noa1305_priv *priv;
192 struct iio_dev *indio_dev;
193 struct regmap *regmap;
194 __le16 data;
195 unsigned int dev_id;
196 int ret;
197
198 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*priv));
199 if (!indio_dev)
200 return -ENOMEM;
201
202 regmap = devm_regmap_init_i2c(client, &noa1305_regmap_config);
203 if (IS_ERR(regmap)) {
204 dev_err(&client->dev, "Regmap initialization failed.\n");
205 return PTR_ERR(regmap);
206 }
207
208 priv = iio_priv(indio_dev);
209
210 ret = devm_regulator_get_enable(&client->dev, "vin");
211 if (ret)
212 return dev_err_probe(&client->dev, ret,
213 "get regulator vin failed\n");
214
215 i2c_set_clientdata(client, indio_dev);
216 priv->client = client;
217 priv->regmap = regmap;
218
219 ret = regmap_bulk_read(regmap, NOA1305_REG_DEVICE_ID_LSB, &data, 2);
220 if (ret < 0) {
221 dev_err(&client->dev, "ID reading failed: %d\n", ret);
222 return ret;
223 }
224
225 dev_id = le16_to_cpu(data);
226 if (dev_id != NOA1305_DEVICE_ID) {
227 dev_err(&client->dev, "Unknown device ID: 0x%x\n", dev_id);
228 return -ENODEV;
229 }
230
231 ret = regmap_write(regmap, NOA1305_REG_POWER_CONTROL,
232 NOA1305_POWER_CONTROL_ON);
233 if (ret < 0) {
234 dev_err(&client->dev, "Enabling power control failed\n");
235 return ret;
236 }
237
238 ret = regmap_write(regmap, NOA1305_REG_RESET, NOA1305_RESET_RESET);
239 if (ret < 0) {
240 dev_err(&client->dev, "Device reset failed\n");
241 return ret;
242 }
243
244 ret = regmap_write(regmap, NOA1305_REG_INTEGRATION_TIME,
245 NOA1305_INTEGR_TIME_800MS);
246 if (ret < 0) {
247 dev_err(&client->dev, "Setting integration time failed\n");
248 return ret;
249 }
250
251 indio_dev->info = &noa1305_info;
252 indio_dev->channels = noa1305_channels;
253 indio_dev->num_channels = ARRAY_SIZE(noa1305_channels);
254 indio_dev->name = NOA1305_DRIVER_NAME;
255 indio_dev->modes = INDIO_DIRECT_MODE;
256
257 ret = devm_iio_device_register(&client->dev, indio_dev);
258 if (ret)
259 dev_err(&client->dev, "registering device failed\n");
260
261 return ret;
262 }
263
264 static const struct of_device_id noa1305_of_match[] = {
265 { .compatible = "onnn,noa1305" },
266 { }
267 };
268 MODULE_DEVICE_TABLE(of, noa1305_of_match);
269
270 static const struct i2c_device_id noa1305_ids[] = {
271 { "noa1305", 0 },
272 { }
273 };
274 MODULE_DEVICE_TABLE(i2c, noa1305_ids);
275
276 static struct i2c_driver noa1305_driver = {
277 .driver = {
278 .name = NOA1305_DRIVER_NAME,
279 .of_match_table = noa1305_of_match,
280 },
281 .probe = noa1305_probe,
282 .id_table = noa1305_ids,
283 };
284
285 module_i2c_driver(noa1305_driver);
286
287 MODULE_AUTHOR("Sergei Miroshnichenko <sergeimir@emcraft.com>");
288 MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.com");
289 MODULE_DESCRIPTION("ON Semiconductor NOA1305 ambient light sensor");
290 MODULE_LICENSE("GPL");
291