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 struct regulator *vin_reg;
50 };
51
noa1305_measure(struct noa1305_priv * priv)52 static int noa1305_measure(struct noa1305_priv *priv)
53 {
54 __le16 data;
55 int ret;
56
57 ret = regmap_bulk_read(priv->regmap, NOA1305_REG_ALS_DATA_LSB, &data,
58 2);
59 if (ret < 0)
60 return ret;
61
62 return le16_to_cpu(data);
63 }
64
noa1305_scale(struct noa1305_priv * priv,int * val,int * val2)65 static int noa1305_scale(struct noa1305_priv *priv, int *val, int *val2)
66 {
67 int data;
68 int ret;
69
70 ret = regmap_read(priv->regmap, NOA1305_REG_INTEGRATION_TIME, &data);
71 if (ret < 0)
72 return ret;
73
74 /*
75 * Lux = count / (<Integration Constant> * <Integration Time>)
76 *
77 * Integration Constant = 7.7
78 * Integration Time in Seconds
79 */
80 switch (data) {
81 case NOA1305_INTEGR_TIME_800MS:
82 *val = 100;
83 *val2 = 77 * 8;
84 break;
85 case NOA1305_INTEGR_TIME_400MS:
86 *val = 100;
87 *val2 = 77 * 4;
88 break;
89 case NOA1305_INTEGR_TIME_200MS:
90 *val = 100;
91 *val2 = 77 * 2;
92 break;
93 case NOA1305_INTEGR_TIME_100MS:
94 *val = 100;
95 *val2 = 77;
96 break;
97 case NOA1305_INTEGR_TIME_50MS:
98 *val = 1000;
99 *val2 = 77 * 5;
100 break;
101 case NOA1305_INTEGR_TIME_25MS:
102 *val = 10000;
103 *val2 = 77 * 25;
104 break;
105 case NOA1305_INTEGR_TIME_12_5MS:
106 *val = 100000;
107 *val2 = 77 * 125;
108 break;
109 case NOA1305_INTEGR_TIME_6_25MS:
110 *val = 1000000;
111 *val2 = 77 * 625;
112 break;
113 default:
114 return -EINVAL;
115 }
116
117 return IIO_VAL_FRACTIONAL;
118 }
119
120 static const struct iio_chan_spec noa1305_channels[] = {
121 {
122 .type = IIO_LIGHT,
123 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
124 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
125 }
126 };
127
noa1305_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)128 static int noa1305_read_raw(struct iio_dev *indio_dev,
129 struct iio_chan_spec const *chan,
130 int *val, int *val2, long mask)
131 {
132 int ret = -EINVAL;
133 struct noa1305_priv *priv = iio_priv(indio_dev);
134
135 switch (mask) {
136 case IIO_CHAN_INFO_RAW:
137 switch (chan->type) {
138 case IIO_LIGHT:
139 ret = noa1305_measure(priv);
140 if (ret < 0)
141 return ret;
142 *val = ret;
143 return IIO_VAL_INT;
144 default:
145 break;
146 }
147 break;
148 case IIO_CHAN_INFO_SCALE:
149 switch (chan->type) {
150 case IIO_LIGHT:
151 return noa1305_scale(priv, val, val2);
152 default:
153 break;
154 }
155 break;
156 default:
157 break;
158 }
159
160 return ret;
161 }
162
163 static const struct iio_info noa1305_info = {
164 .read_raw = noa1305_read_raw,
165 };
166
noa1305_writable_reg(struct device * dev,unsigned int reg)167 static bool noa1305_writable_reg(struct device *dev, unsigned int reg)
168 {
169 switch (reg) {
170 case NOA1305_REG_POWER_CONTROL:
171 case NOA1305_REG_RESET:
172 case NOA1305_REG_INTEGRATION_TIME:
173 case NOA1305_REG_INT_SELECT:
174 case NOA1305_REG_INT_THRESH_LSB:
175 case NOA1305_REG_INT_THRESH_MSB:
176 return true;
177 default:
178 return false;
179 }
180 }
181
182 static const struct regmap_config noa1305_regmap_config = {
183 .name = NOA1305_DRIVER_NAME,
184 .reg_bits = 8,
185 .val_bits = 8,
186 .max_register = NOA1305_REG_DEVICE_ID_MSB,
187 .writeable_reg = noa1305_writable_reg,
188 };
189
noa1305_reg_remove(void * data)190 static void noa1305_reg_remove(void *data)
191 {
192 struct noa1305_priv *priv = data;
193
194 regulator_disable(priv->vin_reg);
195 }
196
noa1305_probe(struct i2c_client * client,const struct i2c_device_id * id)197 static int noa1305_probe(struct i2c_client *client,
198 const struct i2c_device_id *id)
199 {
200 struct noa1305_priv *priv;
201 struct iio_dev *indio_dev;
202 struct regmap *regmap;
203 __le16 data;
204 unsigned int dev_id;
205 int ret;
206
207 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*priv));
208 if (!indio_dev)
209 return -ENOMEM;
210
211 regmap = devm_regmap_init_i2c(client, &noa1305_regmap_config);
212 if (IS_ERR(regmap)) {
213 dev_err(&client->dev, "Regmap initialization failed.\n");
214 return PTR_ERR(regmap);
215 }
216
217 priv = iio_priv(indio_dev);
218
219 priv->vin_reg = devm_regulator_get(&client->dev, "vin");
220 if (IS_ERR(priv->vin_reg))
221 return dev_err_probe(&client->dev, PTR_ERR(priv->vin_reg),
222 "get regulator vin failed\n");
223
224 ret = regulator_enable(priv->vin_reg);
225 if (ret) {
226 dev_err(&client->dev, "enable regulator vin failed\n");
227 return ret;
228 }
229
230 ret = devm_add_action_or_reset(&client->dev, noa1305_reg_remove, priv);
231 if (ret) {
232 dev_err(&client->dev, "addition of devm action failed\n");
233 return ret;
234 }
235
236 i2c_set_clientdata(client, indio_dev);
237 priv->client = client;
238 priv->regmap = regmap;
239
240 ret = regmap_bulk_read(regmap, NOA1305_REG_DEVICE_ID_LSB, &data, 2);
241 if (ret < 0) {
242 dev_err(&client->dev, "ID reading failed: %d\n", ret);
243 return ret;
244 }
245
246 dev_id = le16_to_cpu(data);
247 if (dev_id != NOA1305_DEVICE_ID) {
248 dev_err(&client->dev, "Unknown device ID: 0x%x\n", dev_id);
249 return -ENODEV;
250 }
251
252 ret = regmap_write(regmap, NOA1305_REG_POWER_CONTROL,
253 NOA1305_POWER_CONTROL_ON);
254 if (ret < 0) {
255 dev_err(&client->dev, "Enabling power control failed\n");
256 return ret;
257 }
258
259 ret = regmap_write(regmap, NOA1305_REG_RESET, NOA1305_RESET_RESET);
260 if (ret < 0) {
261 dev_err(&client->dev, "Device reset failed\n");
262 return ret;
263 }
264
265 ret = regmap_write(regmap, NOA1305_REG_INTEGRATION_TIME,
266 NOA1305_INTEGR_TIME_800MS);
267 if (ret < 0) {
268 dev_err(&client->dev, "Setting integration time failed\n");
269 return ret;
270 }
271
272 indio_dev->info = &noa1305_info;
273 indio_dev->channels = noa1305_channels;
274 indio_dev->num_channels = ARRAY_SIZE(noa1305_channels);
275 indio_dev->name = NOA1305_DRIVER_NAME;
276 indio_dev->modes = INDIO_DIRECT_MODE;
277
278 ret = devm_iio_device_register(&client->dev, indio_dev);
279 if (ret)
280 dev_err(&client->dev, "registering device failed\n");
281
282 return ret;
283 }
284
285 static const struct of_device_id noa1305_of_match[] = {
286 { .compatible = "onnn,noa1305" },
287 { }
288 };
289 MODULE_DEVICE_TABLE(of, noa1305_of_match);
290
291 static const struct i2c_device_id noa1305_ids[] = {
292 { "noa1305", 0 },
293 { }
294 };
295 MODULE_DEVICE_TABLE(i2c, noa1305_ids);
296
297 static struct i2c_driver noa1305_driver = {
298 .driver = {
299 .name = NOA1305_DRIVER_NAME,
300 .of_match_table = noa1305_of_match,
301 },
302 .probe = noa1305_probe,
303 .id_table = noa1305_ids,
304 };
305
306 module_i2c_driver(noa1305_driver);
307
308 MODULE_AUTHOR("Sergei Miroshnichenko <sergeimir@emcraft.com>");
309 MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.com");
310 MODULE_DESCRIPTION("ON Semiconductor NOA1305 ambient light sensor");
311 MODULE_LICENSE("GPL");
312