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/of.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
 91	if (ret < 0)
 92		return ret;
 93
 94	ret = i2c_smbus_write_byte_data(data->client, AL3010_REG_CONFIG,
 95					FIELD_PREP(AL3010_GAIN_MASK,
 96						   AL3XXX_RANGE_3));
 97	if (ret < 0)
 98		return ret;
 99
100	return 0;
101}
102
103static int al3010_read_raw(struct iio_dev *indio_dev,
104			   struct iio_chan_spec const *chan, int *val,
105			   int *val2, long mask)
106{
107	struct al3010_data *data = iio_priv(indio_dev);
108	int ret;
109
110	switch (mask) {
111	case IIO_CHAN_INFO_RAW:
112		/*
113		 * ALS ADC value is stored in two adjacent registers:
114		 * - low byte of output is stored at AL3010_REG_DATA_LOW
115		 * - high byte of output is stored at AL3010_REG_DATA_LOW + 1
116		 */
117		ret = i2c_smbus_read_word_data(data->client,
118					       AL3010_REG_DATA_LOW);
119		if (ret < 0)
120			return ret;
121		*val = ret;
122		return IIO_VAL_INT;
123	case IIO_CHAN_INFO_SCALE:
124		ret = i2c_smbus_read_byte_data(data->client,
125					       AL3010_REG_CONFIG);
126		if (ret < 0)
127			return ret;
128
129		ret = FIELD_GET(AL3010_GAIN_MASK, ret);
130		*val = al3010_scales[ret][0];
131		*val2 = al3010_scales[ret][1];
132
133		return IIO_VAL_INT_PLUS_MICRO;
134	}
135	return -EINVAL;
136}
137
138static int al3010_write_raw(struct iio_dev *indio_dev,
139			    struct iio_chan_spec const *chan, int val,
140			    int val2, long mask)
141{
142	struct al3010_data *data = iio_priv(indio_dev);
143	int i;
144
145	switch (mask) {
146	case IIO_CHAN_INFO_SCALE:
147		for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) {
148			if (val != al3010_scales[i][0] ||
149			    val2 != al3010_scales[i][1])
150				continue;
151
152			return i2c_smbus_write_byte_data(data->client,
153					AL3010_REG_CONFIG,
154					FIELD_PREP(AL3010_GAIN_MASK, i));
155		}
156		break;
157	}
158	return -EINVAL;
159}
160
161static const struct iio_info al3010_info = {
162	.read_raw	= al3010_read_raw,
163	.write_raw	= al3010_write_raw,
164	.attrs		= &al3010_attribute_group,
165};
166
167static int al3010_probe(struct i2c_client *client,
168			const struct i2c_device_id *id)
169{
170	struct al3010_data *data;
171	struct iio_dev *indio_dev;
172	int ret;
173
174	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
175	if (!indio_dev)
176		return -ENOMEM;
177
178	data = iio_priv(indio_dev);
179	i2c_set_clientdata(client, indio_dev);
180	data->client = client;
181
182	indio_dev->info = &al3010_info;
183	indio_dev->name = AL3010_DRV_NAME;
184	indio_dev->channels = al3010_channels;
185	indio_dev->num_channels = ARRAY_SIZE(al3010_channels);
186	indio_dev->modes = INDIO_DIRECT_MODE;
187
188	ret = al3010_init(data);
189	if (ret < 0) {
190		dev_err(&client->dev, "al3010 chip init failed\n");
191		return ret;
192	}
193
194	ret = devm_add_action_or_reset(&client->dev,
195					al3010_set_pwr_off,
196					data);
197	if (ret < 0)
198		return ret;
199
200	return devm_iio_device_register(&client->dev, indio_dev);
201}
202
203static int __maybe_unused al3010_suspend(struct device *dev)
204{
205	return al3010_set_pwr(to_i2c_client(dev), false);
206}
207
208static int __maybe_unused al3010_resume(struct device *dev)
209{
210	return al3010_set_pwr(to_i2c_client(dev), true);
211}
212
213static SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume);
214
215static const struct i2c_device_id al3010_id[] = {
216	{"al3010", },
217	{}
218};
219MODULE_DEVICE_TABLE(i2c, al3010_id);
220
221static const struct of_device_id al3010_of_match[] = {
222	{ .compatible = "dynaimage,al3010", },
223	{},
224};
225MODULE_DEVICE_TABLE(of, al3010_of_match);
226
227static struct i2c_driver al3010_driver = {
228	.driver = {
229		.name = AL3010_DRV_NAME,
230		.of_match_table = al3010_of_match,
231		.pm = &al3010_pm_ops,
232	},
233	.probe		= al3010_probe,
234	.id_table	= al3010_id,
235};
236module_i2c_driver(al3010_driver);
237
238MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
239MODULE_AUTHOR("David Heidelberg <david@ixit.cz>");
240MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver");
241MODULE_LICENSE("GPL v2");