1/*
  2 * tsl4531.c - Support for TAOS TSL4531 ambient light sensor
  3 *
  4 * Copyright 2013 Peter Meerwald <pmeerw@pmeerw.net>
  5 *
  6 * This file is subject to the terms and conditions of version 2 of
  7 * the GNU General Public License.  See the file COPYING in the main
  8 * directory of this archive for more details.
  9 *
 10 * IIO driver for the TSL4531x family
 11 *   TSL45311/TSL45313: 7-bit I2C slave address 0x39
 12 *   TSL45315/TSL45317: 7-bit I2C slave address 0x29
 13 *
 14 * TODO: single cycle measurement
 15 */
 16
 17#include <linux/module.h>
 18#include <linux/i2c.h>
 19#include <linux/err.h>
 20#include <linux/delay.h>
 21
 22#include <linux/iio/iio.h>
 23#include <linux/iio/sysfs.h>
 24
 25#define TSL4531_DRV_NAME "tsl4531"
 26
 27#define TSL4531_COMMAND BIT(7)
 28
 29#define TSL4531_CONTROL (TSL4531_COMMAND | 0x00)
 30#define TSL4531_CONFIG (TSL4531_COMMAND | 0x01)
 31#define TSL4531_DATA (TSL4531_COMMAND | 0x04)
 32#define TSL4531_ID (TSL4531_COMMAND | 0x0a)
 33
 34/* operating modes in control register */
 35#define TSL4531_MODE_POWERDOWN 0x00
 36#define TSL4531_MODE_SINGLE_ADC 0x02
 37#define TSL4531_MODE_NORMAL 0x03
 38
 39/* integration time control in config register */
 40#define TSL4531_TCNTRL_400MS 0x00
 41#define TSL4531_TCNTRL_200MS 0x01
 42#define TSL4531_TCNTRL_100MS 0x02
 43
 44/* part number in id register */
 45#define TSL45311_ID 0x8
 46#define TSL45313_ID 0x9
 47#define TSL45315_ID 0xa
 48#define TSL45317_ID 0xb
 49#define TSL4531_ID_SHIFT 4
 50
 51struct tsl4531_data {
 52	struct i2c_client *client;
 53	struct mutex lock;
 54	int int_time;
 55};
 56
 57static IIO_CONST_ATTR_INT_TIME_AVAIL("0.1 0.2 0.4");
 58
 59static struct attribute *tsl4531_attributes[] = {
 60	&iio_const_attr_integration_time_available.dev_attr.attr,
 61	NULL
 62};
 63
 64static const struct attribute_group tsl4531_attribute_group = {
 65	.attrs = tsl4531_attributes,
 66};
 67
 68static const struct iio_chan_spec tsl4531_channels[] = {
 69	{
 70		.type = IIO_LIGHT,
 71		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 72			BIT(IIO_CHAN_INFO_SCALE) |
 73			BIT(IIO_CHAN_INFO_INT_TIME)
 74	}
 75};
 76
 77static int tsl4531_read_raw(struct iio_dev *indio_dev,
 78				struct iio_chan_spec const *chan,
 79				int *val, int *val2, long mask)
 80{
 81	struct tsl4531_data *data = iio_priv(indio_dev);
 82	int ret;
 83
 84	switch (mask) {
 85	case IIO_CHAN_INFO_RAW:
 86		ret = i2c_smbus_read_word_data(data->client,
 87			TSL4531_DATA);
 88		if (ret < 0)
 89			return ret;
 90		*val = ret;
 91		return IIO_VAL_INT;
 92	case IIO_CHAN_INFO_SCALE:
 93		/* 0.. 1x, 1 .. 2x, 2 .. 4x */
 94		*val = 1 << data->int_time;
 95		return IIO_VAL_INT;
 96	case IIO_CHAN_INFO_INT_TIME:
 97		if (data->int_time == 0)
 98			*val2 = 400000;
 99		else if (data->int_time == 1)
100			*val2 = 200000;
101		else if (data->int_time == 2)
102			*val2 = 100000;
103		else
104			return -EINVAL;
105		*val = 0;
106		return IIO_VAL_INT_PLUS_MICRO;
107	default:
108		return -EINVAL;
109	}
110}
111
112static int tsl4531_write_raw(struct iio_dev *indio_dev,
113			     struct iio_chan_spec const *chan,
114			     int val, int val2, long mask)
115{
116	struct tsl4531_data *data = iio_priv(indio_dev);
117	int int_time, ret;
118
119	switch (mask) {
120	case IIO_CHAN_INFO_INT_TIME:
121		if (val != 0)
122			return -EINVAL;
123		if (val2 == 400000)
124			int_time = 0;
125		else if (val2 == 200000)
126			int_time = 1;
127		else if (val2 == 100000)
128			int_time = 2;
129		else
130			return -EINVAL;
131		mutex_lock(&data->lock);
132		ret = i2c_smbus_write_byte_data(data->client,
133			TSL4531_CONFIG, int_time);
134		if (ret >= 0)
135			data->int_time = int_time;
136		mutex_unlock(&data->lock);
137		return ret;
138	default:
139		return -EINVAL;
140	}
141}
142
143static const struct iio_info tsl4531_info = {
144	.read_raw = tsl4531_read_raw,
145	.write_raw = tsl4531_write_raw,
146	.attrs = &tsl4531_attribute_group,
147};
148
149static int tsl4531_check_id(struct i2c_client *client)
150{
151	int ret = i2c_smbus_read_byte_data(client, TSL4531_ID);
152	if (ret < 0)
153		return ret;
154
155	switch (ret >> TSL4531_ID_SHIFT) {
156	case TSL45311_ID:
157	case TSL45313_ID:
158	case TSL45315_ID:
159	case TSL45317_ID:
160		return 0;
161	default:
162		return -ENODEV;
163	}
164}
165
166static int tsl4531_probe(struct i2c_client *client,
167			  const struct i2c_device_id *id)
168{
169	struct tsl4531_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	mutex_init(&data->lock);
181
182	ret = tsl4531_check_id(client);
183	if (ret) {
184		dev_err(&client->dev, "no TSL4531 sensor\n");
185		return ret;
186	}
187
188	ret = i2c_smbus_write_byte_data(data->client, TSL4531_CONTROL,
189		TSL4531_MODE_NORMAL);
190	if (ret < 0)
191		return ret;
192
193	ret = i2c_smbus_write_byte_data(data->client, TSL4531_CONFIG,
194		TSL4531_TCNTRL_400MS);
195	if (ret < 0)
196		return ret;
197
198	indio_dev->dev.parent = &client->dev;
199	indio_dev->info = &tsl4531_info;
200	indio_dev->channels = tsl4531_channels;
201	indio_dev->num_channels = ARRAY_SIZE(tsl4531_channels);
202	indio_dev->name = TSL4531_DRV_NAME;
203	indio_dev->modes = INDIO_DIRECT_MODE;
204
205	return iio_device_register(indio_dev);
206}
207
208static int tsl4531_powerdown(struct i2c_client *client)
209{
210	return i2c_smbus_write_byte_data(client, TSL4531_CONTROL,
211		TSL4531_MODE_POWERDOWN);
212}
213
214static int tsl4531_remove(struct i2c_client *client)
215{
216	iio_device_unregister(i2c_get_clientdata(client));
217	tsl4531_powerdown(client);
218
219	return 0;
220}
221
222#ifdef CONFIG_PM_SLEEP
223static int tsl4531_suspend(struct device *dev)
224{
225	return tsl4531_powerdown(to_i2c_client(dev));
226}
227
228static int tsl4531_resume(struct device *dev)
229{
230	return i2c_smbus_write_byte_data(to_i2c_client(dev), TSL4531_CONTROL,
231		TSL4531_MODE_NORMAL);
232}
233
234static SIMPLE_DEV_PM_OPS(tsl4531_pm_ops, tsl4531_suspend, tsl4531_resume);
235#define TSL4531_PM_OPS (&tsl4531_pm_ops)
236#else
237#define TSL4531_PM_OPS NULL
238#endif
239
240static const struct i2c_device_id tsl4531_id[] = {
241	{ "tsl4531", 0 },
242	{ }
243};
244MODULE_DEVICE_TABLE(i2c, tsl4531_id);
245
246static struct i2c_driver tsl4531_driver = {
247	.driver = {
248		.name   = TSL4531_DRV_NAME,
249		.pm	= TSL4531_PM_OPS,
250	},
251	.probe  = tsl4531_probe,
252	.remove = tsl4531_remove,
253	.id_table = tsl4531_id,
254};
255
256module_i2c_driver(tsl4531_driver);
257
258MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
259MODULE_DESCRIPTION("TAOS TSL4531 ambient light sensors driver");
260MODULE_LICENSE("GPL");