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
46struct noa1305_priv {
47	struct i2c_client *client;
48	struct regmap *regmap;
49};
50
51static 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
64static 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
119static 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
127static 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
162static const struct iio_info noa1305_info = {
163	.read_raw = noa1305_read_raw,
164};
165
166static 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
181static 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
189static 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
264static const struct of_device_id noa1305_of_match[] = {
265	{ .compatible = "onnn,noa1305" },
266	{ }
267};
268MODULE_DEVICE_TABLE(of, noa1305_of_match);
269
270static const struct i2c_device_id noa1305_ids[] = {
271	{ "noa1305", 0 },
272	{ }
273};
274MODULE_DEVICE_TABLE(i2c, noa1305_ids);
275
276static 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
285module_i2c_driver(noa1305_driver);
286
287MODULE_AUTHOR("Sergei Miroshnichenko <sergeimir@emcraft.com>");
288MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.com");
289MODULE_DESCRIPTION("ON Semiconductor NOA1305 ambient light sensor");
290MODULE_LICENSE("GPL");
291