1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * AL3010 - Dyna Image Ambient Light Sensor
  4 *
  5 * Copyright (c) 2014, Intel Corporation.
  6 * Copyright (c) 2016, Dyna-Image Corp.
  7 * Copyright (c) 2020, David Heidelberg, Michał Mirosław, Dmitry Osipenko
  8 *
  9 * IIO driver for AL3010 (7-bit I2C slave address 0x1C).
 10 *
 11 * TODO: interrupt support, thresholds
 12 * When the driver will get support for interrupt handling, then interrupt
 13 * will need to be disabled before turning sensor OFF in order to avoid
 14 * potential races with the interrupt handling.
 15 */
 16
 17#include <linux/bitfield.h>
 18#include <linux/i2c.h>
 19#include <linux/module.h>
 20#include <linux/mod_devicetable.h>
 21
 22#include <linux/iio/iio.h>
 23#include <linux/iio/sysfs.h>
 24
 25#define AL3010_DRV_NAME "al3010"
 26
 27#define AL3010_REG_SYSTEM		0x00
 28#define AL3010_REG_DATA_LOW		0x0c
 29#define AL3010_REG_CONFIG		0x10
 30
 31#define AL3010_CONFIG_DISABLE		0x00
 32#define AL3010_CONFIG_ENABLE		0x01
 33
 34#define AL3010_GAIN_MASK		GENMASK(6,4)
 35
 36#define AL3010_SCALE_AVAILABLE "1.1872 0.2968 0.0742 0.018"
 37
 38enum al3xxxx_range {
 39	AL3XXX_RANGE_1, /* 77806 lx */
 40	AL3XXX_RANGE_2, /* 19542 lx */
 41	AL3XXX_RANGE_3, /*  4863 lx */
 42	AL3XXX_RANGE_4  /*  1216 lx */
 43};
 44
 45static const int al3010_scales[][2] = {
 46	{0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600}
 47};
 48
 49struct al3010_data {
 50	struct i2c_client *client;
 51};
 52
 53static const struct iio_chan_spec al3010_channels[] = {
 54	{
 55		.type	= IIO_LIGHT,
 56		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 57				      BIT(IIO_CHAN_INFO_SCALE),
 58	}
 59};
 60
 61static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE);
 62
 63static struct attribute *al3010_attributes[] = {
 64	&iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
 65	NULL,
 66};
 67
 68static const struct attribute_group al3010_attribute_group = {
 69	.attrs = al3010_attributes,
 70};
 71
 72static int al3010_set_pwr(struct i2c_client *client, bool pwr)
 73{
 74	u8 val = pwr ? AL3010_CONFIG_ENABLE : AL3010_CONFIG_DISABLE;
 75	return i2c_smbus_write_byte_data(client, AL3010_REG_SYSTEM, val);
 76}
 77
 78static void al3010_set_pwr_off(void *_data)
 79{
 80	struct al3010_data *data = _data;
 81
 82	al3010_set_pwr(data->client, false);
 83}
 84
 85static int al3010_init(struct al3010_data *data)
 86{
 87	int ret;
 88
 89	ret = al3010_set_pwr(data->client, true);
 90	if (ret < 0)
 91		return ret;
 92
 93	ret = devm_add_action_or_reset(&data->client->dev,
 94				       al3010_set_pwr_off,
 95				       data);
 96	if (ret < 0)
 97		return ret;
 98
 99	ret = i2c_smbus_write_byte_data(data->client, AL3010_REG_CONFIG,
100					FIELD_PREP(AL3010_GAIN_MASK,
101						   AL3XXX_RANGE_3));
102	if (ret < 0)
103		return ret;
104
105	return 0;
106}
107
108static int al3010_read_raw(struct iio_dev *indio_dev,
109			   struct iio_chan_spec const *chan, int *val,
110			   int *val2, long mask)
111{
112	struct al3010_data *data = iio_priv(indio_dev);
113	int ret;
114
115	switch (mask) {
116	case IIO_CHAN_INFO_RAW:
117		/*
118		 * ALS ADC value is stored in two adjacent registers:
119		 * - low byte of output is stored at AL3010_REG_DATA_LOW
120		 * - high byte of output is stored at AL3010_REG_DATA_LOW + 1
121		 */
122		ret = i2c_smbus_read_word_data(data->client,
123					       AL3010_REG_DATA_LOW);
124		if (ret < 0)
125			return ret;
126		*val = ret;
127		return IIO_VAL_INT;
128	case IIO_CHAN_INFO_SCALE:
129		ret = i2c_smbus_read_byte_data(data->client,
130					       AL3010_REG_CONFIG);
131		if (ret < 0)
132			return ret;
133
134		ret = FIELD_GET(AL3010_GAIN_MASK, ret);
135		*val = al3010_scales[ret][0];
136		*val2 = al3010_scales[ret][1];
137
138		return IIO_VAL_INT_PLUS_MICRO;
139	}
140	return -EINVAL;
141}
142
143static int al3010_write_raw(struct iio_dev *indio_dev,
144			    struct iio_chan_spec const *chan, int val,
145			    int val2, long mask)
146{
147	struct al3010_data *data = iio_priv(indio_dev);
148	int i;
149
150	switch (mask) {
151	case IIO_CHAN_INFO_SCALE:
152		for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) {
153			if (val != al3010_scales[i][0] ||
154			    val2 != al3010_scales[i][1])
155				continue;
156
157			return i2c_smbus_write_byte_data(data->client,
158					AL3010_REG_CONFIG,
159					FIELD_PREP(AL3010_GAIN_MASK, i));
160		}
161		break;
162	}
163	return -EINVAL;
164}
165
166static const struct iio_info al3010_info = {
167	.read_raw	= al3010_read_raw,
168	.write_raw	= al3010_write_raw,
169	.attrs		= &al3010_attribute_group,
170};
171
172static int al3010_probe(struct i2c_client *client)
173{
174	struct al3010_data *data;
175	struct iio_dev *indio_dev;
176	int ret;
177
178	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
179	if (!indio_dev)
180		return -ENOMEM;
181
182	data = iio_priv(indio_dev);
183	i2c_set_clientdata(client, indio_dev);
184	data->client = client;
185
186	indio_dev->info = &al3010_info;
187	indio_dev->name = AL3010_DRV_NAME;
188	indio_dev->channels = al3010_channels;
189	indio_dev->num_channels = ARRAY_SIZE(al3010_channels);
190	indio_dev->modes = INDIO_DIRECT_MODE;
191
192	ret = al3010_init(data);
193	if (ret < 0) {
194		dev_err(&client->dev, "al3010 chip init failed\n");
195		return ret;
196	}
197
198	return devm_iio_device_register(&client->dev, indio_dev);
199}
200
201static int al3010_suspend(struct device *dev)
202{
203	return al3010_set_pwr(to_i2c_client(dev), false);
204}
205
206static int al3010_resume(struct device *dev)
207{
208	return al3010_set_pwr(to_i2c_client(dev), true);
209}
210
211static DEFINE_SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume);
212
213static const struct i2c_device_id al3010_id[] = {
214	{"al3010", },
215	{}
216};
217MODULE_DEVICE_TABLE(i2c, al3010_id);
218
219static const struct of_device_id al3010_of_match[] = {
220	{ .compatible = "dynaimage,al3010", },
221	{},
222};
223MODULE_DEVICE_TABLE(of, al3010_of_match);
224
225static struct i2c_driver al3010_driver = {
226	.driver = {
227		.name = AL3010_DRV_NAME,
228		.of_match_table = al3010_of_match,
229		.pm = pm_sleep_ptr(&al3010_pm_ops),
230	},
231	.probe		= al3010_probe,
232	.id_table	= al3010_id,
233};
234module_i2c_driver(al3010_driver);
235
236MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
237MODULE_AUTHOR("David Heidelberg <david@ixit.cz>");
238MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver");
239MODULE_LICENSE("GPL v2");