xref: /openbmc/linux/drivers/iio/light/al3010.c (revision 7cf15f42)
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 
38 enum 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 
45 static const int al3010_scales[][2] = {
46 	{0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600}
47 };
48 
49 struct al3010_data {
50 	struct i2c_client *client;
51 };
52 
53 static 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 
61 static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE);
62 
63 static struct attribute *al3010_attributes[] = {
64 	&iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
65 	NULL,
66 };
67 
68 static const struct attribute_group al3010_attribute_group = {
69 	.attrs = al3010_attributes,
70 };
71 
al3010_set_pwr(struct i2c_client * client,bool pwr)72 static 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 
al3010_set_pwr_off(void * _data)78 static void al3010_set_pwr_off(void *_data)
79 {
80 	struct al3010_data *data = _data;
81 
82 	al3010_set_pwr(data->client, false);
83 }
84 
al3010_init(struct al3010_data * data)85 static 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 
al3010_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)103 static 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 
al3010_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)138 static 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 
161 static 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 
al3010_probe(struct i2c_client * client)167 static int al3010_probe(struct i2c_client *client)
168 {
169 	struct al3010_data *data;
170 	struct iio_dev *indio_dev;
171 	int ret;
172 
173 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
174 	if (!indio_dev)
175 		return -ENOMEM;
176 
177 	data = iio_priv(indio_dev);
178 	i2c_set_clientdata(client, indio_dev);
179 	data->client = client;
180 
181 	indio_dev->info = &al3010_info;
182 	indio_dev->name = AL3010_DRV_NAME;
183 	indio_dev->channels = al3010_channels;
184 	indio_dev->num_channels = ARRAY_SIZE(al3010_channels);
185 	indio_dev->modes = INDIO_DIRECT_MODE;
186 
187 	ret = al3010_init(data);
188 	if (ret < 0) {
189 		dev_err(&client->dev, "al3010 chip init failed\n");
190 		return ret;
191 	}
192 
193 	ret = devm_add_action_or_reset(&client->dev,
194 					al3010_set_pwr_off,
195 					data);
196 	if (ret < 0)
197 		return ret;
198 
199 	return devm_iio_device_register(&client->dev, indio_dev);
200 }
201 
al3010_suspend(struct device * dev)202 static int al3010_suspend(struct device *dev)
203 {
204 	return al3010_set_pwr(to_i2c_client(dev), false);
205 }
206 
al3010_resume(struct device * dev)207 static int al3010_resume(struct device *dev)
208 {
209 	return al3010_set_pwr(to_i2c_client(dev), true);
210 }
211 
212 static DEFINE_SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume);
213 
214 static const struct i2c_device_id al3010_id[] = {
215 	{"al3010", },
216 	{}
217 };
218 MODULE_DEVICE_TABLE(i2c, al3010_id);
219 
220 static const struct of_device_id al3010_of_match[] = {
221 	{ .compatible = "dynaimage,al3010", },
222 	{},
223 };
224 MODULE_DEVICE_TABLE(of, al3010_of_match);
225 
226 static struct i2c_driver al3010_driver = {
227 	.driver = {
228 		.name = AL3010_DRV_NAME,
229 		.of_match_table = al3010_of_match,
230 		.pm = pm_sleep_ptr(&al3010_pm_ops),
231 	},
232 	.probe		= al3010_probe,
233 	.id_table	= al3010_id,
234 };
235 module_i2c_driver(al3010_driver);
236 
237 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
238 MODULE_AUTHOR("David Heidelberg <david@ixit.cz>");
239 MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver");
240 MODULE_LICENSE("GPL v2");
241