al3010.c

  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/regmap.h>
 21#include <linux/mod_devicetable.h>
 22
 23#include <linux/iio/iio.h>
 24#include <linux/iio/sysfs.h>
 25
 26#define AL3010_REG_SYSTEM		0x00
 27#define AL3010_REG_DATA_LOW		0x0c
 28#define AL3010_REG_CONFIG		0x10
 29
 30#define AL3010_CONFIG_DISABLE		0x00
 31#define AL3010_CONFIG_ENABLE		0x01
 32
 33#define AL3010_GAIN_MASK		GENMASK(6,4)
 34
 35#define AL3010_SCALE_AVAILABLE "1.1872 0.2968 0.0742 0.018"
 36
 37enum al3xxxx_range {
 38	AL3XXX_RANGE_1, /* 77806 lx */
 39	AL3XXX_RANGE_2, /* 19542 lx */
 40	AL3XXX_RANGE_3, /*  4863 lx */
 41	AL3XXX_RANGE_4  /*  1216 lx */
 42};
 43
 44static const int al3010_scales[][2] = {
 45	{0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600}
 46};
 47
 48static const struct regmap_config al3010_regmap_config = {
 49	.reg_bits = 8,
 50	.val_bits = 8,
 51	.max_register = AL3010_REG_CONFIG,
 52};
 53
 54struct al3010_data {
 55	struct regmap *regmap;
 56};
 57
 58static const struct iio_chan_spec al3010_channels[] = {
 59	{
 60		.type	= IIO_LIGHT,
 61		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 62				      BIT(IIO_CHAN_INFO_SCALE),
 63	}
 64};
 65
 66static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE);
 67
 68static struct attribute *al3010_attributes[] = {
 69	&iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
 70	NULL,
 71};
 72
 73static const struct attribute_group al3010_attribute_group = {
 74	.attrs = al3010_attributes,
 75};
 76
 77static int al3010_set_pwr_on(struct al3010_data *data)
 78{
 79	return regmap_write(data->regmap, AL3010_REG_SYSTEM, AL3010_CONFIG_ENABLE);
 80}
 81
 82static void al3010_set_pwr_off(void *_data)
 83{
 84	struct al3010_data *data = _data;
 85	struct device *dev = regmap_get_device(data->regmap);
 86	int ret;
 87
 88	ret = regmap_write(data->regmap, AL3010_REG_SYSTEM, AL3010_CONFIG_DISABLE);
 89	if (ret)
 90		dev_err(dev, "failed to write system register\n");
 91}
 92
 93static int al3010_init(struct al3010_data *data)
 94{
 95	struct device *dev = regmap_get_device(data->regmap);
 96	int ret;
 97
 98	ret = al3010_set_pwr_on(data);
 99	if (ret)
100		return ret;
101
102	ret = devm_add_action_or_reset(dev, al3010_set_pwr_off, data);
103	if (ret)
104		return ret;
105	return regmap_write(data->regmap, AL3010_REG_CONFIG,
106			    FIELD_PREP(AL3010_GAIN_MASK, AL3XXX_RANGE_3));
107}
108
109static int al3010_read_raw(struct iio_dev *indio_dev,
110			   struct iio_chan_spec const *chan, int *val,
111			   int *val2, long mask)
112{
113	struct al3010_data *data = iio_priv(indio_dev);
114	int ret, gain, raw;
115
116	switch (mask) {
117	case IIO_CHAN_INFO_RAW:
118		/*
119		 * ALS ADC value is stored in two adjacent registers:
120		 * - low byte of output is stored at AL3010_REG_DATA_LOW
121		 * - high byte of output is stored at AL3010_REG_DATA_LOW + 1
122		 */
123		ret = regmap_read(data->regmap, AL3010_REG_DATA_LOW, &raw);
124		if (ret)
125			return ret;
126
127		*val = raw;
128
129		return IIO_VAL_INT;
130	case IIO_CHAN_INFO_SCALE:
131		ret = regmap_read(data->regmap, AL3010_REG_CONFIG, &gain);
132		if (ret)
133			return ret;
134
135		gain = FIELD_GET(AL3010_GAIN_MASK, gain);
136		*val = al3010_scales[gain][0];
137		*val2 = al3010_scales[gain][1];
138
139		return IIO_VAL_INT_PLUS_MICRO;
140	}
141	return -EINVAL;
142}
143
144static int al3010_write_raw(struct iio_dev *indio_dev,
145			    struct iio_chan_spec const *chan, int val,
146			    int val2, long mask)
147{
148	struct al3010_data *data = iio_priv(indio_dev);
149	unsigned int i;
150
151	switch (mask) {
152	case IIO_CHAN_INFO_SCALE:
153		for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) {
154			if (val != al3010_scales[i][0] ||
155			    val2 != al3010_scales[i][1])
156				continue;
157
158			return regmap_write(data->regmap, 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 device *dev = &client->dev;
176	struct iio_dev *indio_dev;
177	int ret;
178
179	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
180	if (!indio_dev)
181		return -ENOMEM;
182
183	data = iio_priv(indio_dev);
184	i2c_set_clientdata(client, indio_dev);
185	data->regmap = devm_regmap_init_i2c(client, &al3010_regmap_config);
186	if (IS_ERR(data->regmap))
187		return dev_err_probe(dev, PTR_ERR(data->regmap),
188				     "cannot allocate regmap\n");
189
190	indio_dev->info = &al3010_info;
191	indio_dev->name = "al3010";
192	indio_dev->channels = al3010_channels;
193	indio_dev->num_channels = ARRAY_SIZE(al3010_channels);
194	indio_dev->modes = INDIO_DIRECT_MODE;
195
196	ret = al3010_init(data);
197	if (ret)
198		return dev_err_probe(dev, ret, "failed to init ALS\n");
199
200	return devm_iio_device_register(dev, indio_dev);
201}
202
203static int al3010_suspend(struct device *dev)
204{
205	struct al3010_data *data = iio_priv(dev_get_drvdata(dev));
206
207	al3010_set_pwr_off(data);
208	return 0;
209}
210
211static int al3010_resume(struct device *dev)
212{
213	struct al3010_data *data = iio_priv(dev_get_drvdata(dev));
214
215	return al3010_set_pwr_on(data);
216}
217
218static DEFINE_SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume);
219
220static const struct i2c_device_id al3010_id[] = {
221	{"al3010", },
222	{ }
223};
224MODULE_DEVICE_TABLE(i2c, al3010_id);
225
226static const struct of_device_id al3010_of_match[] = {
227	{ .compatible = "dynaimage,al3010", },
228	{ }
229};
230MODULE_DEVICE_TABLE(of, al3010_of_match);
231
232static struct i2c_driver al3010_driver = {
233	.driver = {
234		.name = "al3010",
235		.of_match_table = al3010_of_match,
236		.pm = pm_sleep_ptr(&al3010_pm_ops),
237	},
238	.probe		= al3010_probe,
239	.id_table	= al3010_id,
240};
241module_i2c_driver(al3010_driver);
242
243MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
244MODULE_AUTHOR("David Heidelberg <david@ixit.cz>");
245MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver");
246MODULE_LICENSE("GPL v2");