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, val);
90}
91
92static void al3320a_set_pwr_off(void *_data)
93{
94	struct al3320a_data *data = _data;
95
96	al3320a_set_pwr(data->client, false);
97}
98
99static int al3320a_init(struct al3320a_data *data)
100{
101	int ret;
102
103	ret = al3320a_set_pwr(data->client, true);
104
105	if (ret < 0)
106		return ret;
107
108	ret = i2c_smbus_write_byte_data(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(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(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(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(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(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(&client->dev, sizeof(*data));
198	if (!indio_dev)
199		return -ENOMEM;
200
201	data = iio_priv(indio_dev);
202	i2c_set_clientdata(client, 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), false);
229}
230
231static int al3320a_resume(struct device *dev)
232{
233	return al3320a_set_pwr(to_i2c_client(dev), 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