1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * tsl4531.c - Support for TAOS TSL4531 ambient light sensor
4  *
5  * Copyright 2013 Peter Meerwald <pmeerw@pmeerw.net>
6  *
7  * IIO driver for the TSL4531x family
8  *   TSL45311/TSL45313: 7-bit I2C slave address 0x39
9  *   TSL45315/TSL45317: 7-bit I2C slave address 0x29
10  *
11  * TODO: single cycle measurement
12  */
13 
14 #include <linux/module.h>
15 #include <linux/i2c.h>
16 #include <linux/err.h>
17 #include <linux/delay.h>
18 
19 #include <linux/iio/iio.h>
20 #include <linux/iio/sysfs.h>
21 
22 #define TSL4531_DRV_NAME "tsl4531"
23 
24 #define TSL4531_COMMAND BIT(7)
25 
26 #define TSL4531_CONTROL (TSL4531_COMMAND | 0x00)
27 #define TSL4531_CONFIG (TSL4531_COMMAND | 0x01)
28 #define TSL4531_DATA (TSL4531_COMMAND | 0x04)
29 #define TSL4531_ID (TSL4531_COMMAND | 0x0a)
30 
31 /* operating modes in control register */
32 #define TSL4531_MODE_POWERDOWN 0x00
33 #define TSL4531_MODE_SINGLE_ADC 0x02
34 #define TSL4531_MODE_NORMAL 0x03
35 
36 /* integration time control in config register */
37 #define TSL4531_TCNTRL_400MS 0x00
38 #define TSL4531_TCNTRL_200MS 0x01
39 #define TSL4531_TCNTRL_100MS 0x02
40 
41 /* part number in id register */
42 #define TSL45311_ID 0x8
43 #define TSL45313_ID 0x9
44 #define TSL45315_ID 0xa
45 #define TSL45317_ID 0xb
46 #define TSL4531_ID_SHIFT 4
47 
48 struct tsl4531_data {
49 	struct i2c_client *client;
50 	struct mutex lock;
51 	int int_time;
52 };
53 
54 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.1 0.2 0.4");
55 
56 static struct attribute *tsl4531_attributes[] = {
57 	&iio_const_attr_integration_time_available.dev_attr.attr,
58 	NULL
59 };
60 
61 static const struct attribute_group tsl4531_attribute_group = {
62 	.attrs = tsl4531_attributes,
63 };
64 
65 static const struct iio_chan_spec tsl4531_channels[] = {
66 	{
67 		.type = IIO_LIGHT,
68 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
69 			BIT(IIO_CHAN_INFO_SCALE) |
70 			BIT(IIO_CHAN_INFO_INT_TIME)
71 	}
72 };
73 
tsl4531_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)74 static int tsl4531_read_raw(struct iio_dev *indio_dev,
75 				struct iio_chan_spec const *chan,
76 				int *val, int *val2, long mask)
77 {
78 	struct tsl4531_data *data = iio_priv(indio_dev);
79 	int ret;
80 
81 	switch (mask) {
82 	case IIO_CHAN_INFO_RAW:
83 		ret = i2c_smbus_read_word_data(data->client,
84 			TSL4531_DATA);
85 		if (ret < 0)
86 			return ret;
87 		*val = ret;
88 		return IIO_VAL_INT;
89 	case IIO_CHAN_INFO_SCALE:
90 		/* 0.. 1x, 1 .. 2x, 2 .. 4x */
91 		*val = 1 << data->int_time;
92 		return IIO_VAL_INT;
93 	case IIO_CHAN_INFO_INT_TIME:
94 		if (data->int_time == 0)
95 			*val2 = 400000;
96 		else if (data->int_time == 1)
97 			*val2 = 200000;
98 		else if (data->int_time == 2)
99 			*val2 = 100000;
100 		else
101 			return -EINVAL;
102 		*val = 0;
103 		return IIO_VAL_INT_PLUS_MICRO;
104 	default:
105 		return -EINVAL;
106 	}
107 }
108 
tsl4531_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)109 static int tsl4531_write_raw(struct iio_dev *indio_dev,
110 			     struct iio_chan_spec const *chan,
111 			     int val, int val2, long mask)
112 {
113 	struct tsl4531_data *data = iio_priv(indio_dev);
114 	int int_time, ret;
115 
116 	switch (mask) {
117 	case IIO_CHAN_INFO_INT_TIME:
118 		if (val != 0)
119 			return -EINVAL;
120 		if (val2 == 400000)
121 			int_time = 0;
122 		else if (val2 == 200000)
123 			int_time = 1;
124 		else if (val2 == 100000)
125 			int_time = 2;
126 		else
127 			return -EINVAL;
128 		mutex_lock(&data->lock);
129 		ret = i2c_smbus_write_byte_data(data->client,
130 			TSL4531_CONFIG, int_time);
131 		if (ret >= 0)
132 			data->int_time = int_time;
133 		mutex_unlock(&data->lock);
134 		return ret;
135 	default:
136 		return -EINVAL;
137 	}
138 }
139 
140 static const struct iio_info tsl4531_info = {
141 	.read_raw = tsl4531_read_raw,
142 	.write_raw = tsl4531_write_raw,
143 	.attrs = &tsl4531_attribute_group,
144 };
145 
tsl4531_check_id(struct i2c_client * client)146 static int tsl4531_check_id(struct i2c_client *client)
147 {
148 	int ret = i2c_smbus_read_byte_data(client, TSL4531_ID);
149 	if (ret < 0)
150 		return ret;
151 
152 	switch (ret >> TSL4531_ID_SHIFT) {
153 	case TSL45311_ID:
154 	case TSL45313_ID:
155 	case TSL45315_ID:
156 	case TSL45317_ID:
157 		return 0;
158 	default:
159 		return -ENODEV;
160 	}
161 }
162 
tsl4531_probe(struct i2c_client * client)163 static int tsl4531_probe(struct i2c_client *client)
164 {
165 	struct tsl4531_data *data;
166 	struct iio_dev *indio_dev;
167 	int ret;
168 
169 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
170 	if (!indio_dev)
171 		return -ENOMEM;
172 
173 	data = iio_priv(indio_dev);
174 	i2c_set_clientdata(client, indio_dev);
175 	data->client = client;
176 	mutex_init(&data->lock);
177 
178 	ret = tsl4531_check_id(client);
179 	if (ret) {
180 		dev_err(&client->dev, "no TSL4531 sensor\n");
181 		return ret;
182 	}
183 
184 	ret = i2c_smbus_write_byte_data(data->client, TSL4531_CONTROL,
185 		TSL4531_MODE_NORMAL);
186 	if (ret < 0)
187 		return ret;
188 
189 	ret = i2c_smbus_write_byte_data(data->client, TSL4531_CONFIG,
190 		TSL4531_TCNTRL_400MS);
191 	if (ret < 0)
192 		return ret;
193 
194 	indio_dev->info = &tsl4531_info;
195 	indio_dev->channels = tsl4531_channels;
196 	indio_dev->num_channels = ARRAY_SIZE(tsl4531_channels);
197 	indio_dev->name = TSL4531_DRV_NAME;
198 	indio_dev->modes = INDIO_DIRECT_MODE;
199 
200 	return iio_device_register(indio_dev);
201 }
202 
tsl4531_powerdown(struct i2c_client * client)203 static int tsl4531_powerdown(struct i2c_client *client)
204 {
205 	return i2c_smbus_write_byte_data(client, TSL4531_CONTROL,
206 		TSL4531_MODE_POWERDOWN);
207 }
208 
tsl4531_remove(struct i2c_client * client)209 static void tsl4531_remove(struct i2c_client *client)
210 {
211 	iio_device_unregister(i2c_get_clientdata(client));
212 	tsl4531_powerdown(client);
213 }
214 
tsl4531_suspend(struct device * dev)215 static int tsl4531_suspend(struct device *dev)
216 {
217 	return tsl4531_powerdown(to_i2c_client(dev));
218 }
219 
tsl4531_resume(struct device * dev)220 static int tsl4531_resume(struct device *dev)
221 {
222 	return i2c_smbus_write_byte_data(to_i2c_client(dev), TSL4531_CONTROL,
223 		TSL4531_MODE_NORMAL);
224 }
225 
226 static DEFINE_SIMPLE_DEV_PM_OPS(tsl4531_pm_ops, tsl4531_suspend,
227 				tsl4531_resume);
228 
229 static const struct i2c_device_id tsl4531_id[] = {
230 	{ "tsl4531", 0 },
231 	{ }
232 };
233 MODULE_DEVICE_TABLE(i2c, tsl4531_id);
234 
235 static struct i2c_driver tsl4531_driver = {
236 	.driver = {
237 		.name   = TSL4531_DRV_NAME,
238 		.pm	= pm_sleep_ptr(&tsl4531_pm_ops),
239 	},
240 	.probe_new = tsl4531_probe,
241 	.remove = tsl4531_remove,
242 	.id_table = tsl4531_id,
243 };
244 
245 module_i2c_driver(tsl4531_driver);
246 
247 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
248 MODULE_DESCRIPTION("TAOS TSL4531 ambient light sensors driver");
249 MODULE_LICENSE("GPL");
250