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23#include <linux/delay.h>
24#include <linux/i2c.h>
25#include <linux/iio/iio.h>
26#include <linux/iio/sysfs.h>
27#include <linux/module.h>
28
29#define BH1750_POWER_DOWN 0x00
30#define BH1750_ONE_TIME_H_RES_MODE 0x20
31#define BH1750_CHANGE_INT_TIME_H_BIT 0x40
32#define BH1750_CHANGE_INT_TIME_L_BIT 0x60
33
34enum {
35 BH1710,
36 BH1721,
37 BH1750,
38};
39
40struct bh1750_chip_info;
41struct bh1750_data {
42 struct i2c_client *client;
43 struct mutex lock;
44 const struct bh1750_chip_info *chip_info;
45 u16 mtreg;
46};
47
48struct bh1750_chip_info {
49 u16 mtreg_min;
50 u16 mtreg_max;
51 u16 mtreg_default;
52 int mtreg_to_usec;
53 int mtreg_to_scale;
54
55
56
57
58
59
60
61 int inc;
62
63 u16 int_time_low_mask;
64 u16 int_time_high_mask;
65}
66
67static const bh1750_chip_info_tbl[] = {
68 [BH1710] = { 140, 1022, 300, 400, 250000000, 2, 0x001F, 0x03E0 },
69 [BH1721] = { 140, 1020, 300, 400, 250000000, 2, 0x0010, 0x03E0 },
70 [BH1750] = { 31, 254, 69, 1740, 57500000, 1, 0x001F, 0x00E0 },
71};
72
73static int bh1750_change_int_time(struct bh1750_data *data, int usec)
74{
75 int ret;
76 u16 val;
77 u8 regval;
78 const struct bh1750_chip_info *chip_info = data->chip_info;
79
80 if ((usec % chip_info->mtreg_to_usec) != 0)
81 return -EINVAL;
82
83 val = usec / chip_info->mtreg_to_usec;
84 if (val < chip_info->mtreg_min || val > chip_info->mtreg_max)
85 return -EINVAL;
86
87 ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN);
88 if (ret < 0)
89 return ret;
90
91 regval = (val & chip_info->int_time_high_mask) >> 5;
92 ret = i2c_smbus_write_byte(data->client,
93 BH1750_CHANGE_INT_TIME_H_BIT | regval);
94 if (ret < 0)
95 return ret;
96
97 regval = val & chip_info->int_time_low_mask;
98 ret = i2c_smbus_write_byte(data->client,
99 BH1750_CHANGE_INT_TIME_L_BIT | regval);
100 if (ret < 0)
101 return ret;
102
103 data->mtreg = val;
104
105 return 0;
106}
107
108static int bh1750_read(struct bh1750_data *data, int *val)
109{
110 int ret;
111 __be16 result;
112 const struct bh1750_chip_info *chip_info = data->chip_info;
113 unsigned long delay = chip_info->mtreg_to_usec * data->mtreg;
114
115
116
117
118
119 ret = i2c_smbus_write_byte(data->client, BH1750_ONE_TIME_H_RES_MODE);
120 if (ret < 0)
121 return ret;
122
123 usleep_range(delay + 15000, delay + 40000);
124
125 ret = i2c_master_recv(data->client, (char *)&result, 2);
126 if (ret < 0)
127 return ret;
128
129 *val = be16_to_cpu(result);
130
131 return 0;
132}
133
134static int bh1750_read_raw(struct iio_dev *indio_dev,
135 struct iio_chan_spec const *chan,
136 int *val, int *val2, long mask)
137{
138 int ret, tmp;
139 struct bh1750_data *data = iio_priv(indio_dev);
140 const struct bh1750_chip_info *chip_info = data->chip_info;
141
142 switch (mask) {
143 case IIO_CHAN_INFO_RAW:
144 switch (chan->type) {
145 case IIO_LIGHT:
146 mutex_lock(&data->lock);
147 ret = bh1750_read(data, val);
148 mutex_unlock(&data->lock);
149 if (ret < 0)
150 return ret;
151
152 return IIO_VAL_INT;
153 default:
154 return -EINVAL;
155 }
156 case IIO_CHAN_INFO_SCALE:
157 tmp = chip_info->mtreg_to_scale / data->mtreg;
158 *val = tmp / 1000000;
159 *val2 = tmp % 1000000;
160 return IIO_VAL_INT_PLUS_MICRO;
161 case IIO_CHAN_INFO_INT_TIME:
162 *val = 0;
163 *val2 = chip_info->mtreg_to_usec * data->mtreg;
164 return IIO_VAL_INT_PLUS_MICRO;
165 default:
166 return -EINVAL;
167 }
168}
169
170static int bh1750_write_raw(struct iio_dev *indio_dev,
171 struct iio_chan_spec const *chan,
172 int val, int val2, long mask)
173{
174 int ret;
175 struct bh1750_data *data = iio_priv(indio_dev);
176
177 switch (mask) {
178 case IIO_CHAN_INFO_INT_TIME:
179 if (val != 0)
180 return -EINVAL;
181
182 mutex_lock(&data->lock);
183 ret = bh1750_change_int_time(data, val2);
184 mutex_unlock(&data->lock);
185 return ret;
186 default:
187 return -EINVAL;
188 }
189}
190
191static ssize_t bh1750_show_int_time_available(struct device *dev,
192 struct device_attribute *attr, char *buf)
193{
194 int i;
195 size_t len = 0;
196 struct bh1750_data *data = iio_priv(dev_to_iio_dev(dev));
197 const struct bh1750_chip_info *chip_info = data->chip_info;
198
199 for (i = chip_info->mtreg_min; i <= chip_info->mtreg_max; i += chip_info->inc)
200 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
201 chip_info->mtreg_to_usec * i);
202
203 buf[len - 1] = '\n';
204
205 return len;
206}
207
208static IIO_DEV_ATTR_INT_TIME_AVAIL(bh1750_show_int_time_available);
209
210static struct attribute *bh1750_attributes[] = {
211 &iio_dev_attr_integration_time_available.dev_attr.attr,
212 NULL,
213};
214
215static struct attribute_group bh1750_attribute_group = {
216 .attrs = bh1750_attributes,
217};
218
219static const struct iio_info bh1750_info = {
220 .driver_module = THIS_MODULE,
221 .attrs = &bh1750_attribute_group,
222 .read_raw = bh1750_read_raw,
223 .write_raw = bh1750_write_raw,
224};
225
226static const struct iio_chan_spec bh1750_channels[] = {
227 {
228 .type = IIO_LIGHT,
229 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
230 BIT(IIO_CHAN_INFO_SCALE) |
231 BIT(IIO_CHAN_INFO_INT_TIME)
232 }
233};
234
235static int bh1750_probe(struct i2c_client *client,
236 const struct i2c_device_id *id)
237{
238 int ret, usec;
239 struct bh1750_data *data;
240 struct iio_dev *indio_dev;
241
242 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
243 I2C_FUNC_SMBUS_WRITE_BYTE))
244 return -EOPNOTSUPP;
245
246 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
247 if (!indio_dev)
248 return -ENOMEM;
249
250 data = iio_priv(indio_dev);
251 i2c_set_clientdata(client, indio_dev);
252 data->client = client;
253 data->chip_info = &bh1750_chip_info_tbl[id->driver_data];
254
255 usec = data->chip_info->mtreg_to_usec * data->chip_info->mtreg_default;
256 ret = bh1750_change_int_time(data, usec);
257 if (ret < 0)
258 return ret;
259
260 mutex_init(&data->lock);
261 indio_dev->dev.parent = &client->dev;
262 indio_dev->info = &bh1750_info;
263 indio_dev->name = id->name;
264 indio_dev->channels = bh1750_channels;
265 indio_dev->num_channels = ARRAY_SIZE(bh1750_channels);
266 indio_dev->modes = INDIO_DIRECT_MODE;
267
268 return iio_device_register(indio_dev);
269}
270
271static int bh1750_remove(struct i2c_client *client)
272{
273 struct iio_dev *indio_dev = i2c_get_clientdata(client);
274 struct bh1750_data *data = iio_priv(indio_dev);
275
276 iio_device_unregister(indio_dev);
277
278 mutex_lock(&data->lock);
279 i2c_smbus_write_byte(client, BH1750_POWER_DOWN);
280 mutex_unlock(&data->lock);
281
282 return 0;
283}
284
285#ifdef CONFIG_PM_SLEEP
286static int bh1750_suspend(struct device *dev)
287{
288 int ret;
289 struct bh1750_data *data =
290 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
291
292
293
294
295
296 mutex_lock(&data->lock);
297 ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN);
298 mutex_unlock(&data->lock);
299
300 return ret;
301}
302
303static SIMPLE_DEV_PM_OPS(bh1750_pm_ops, bh1750_suspend, NULL);
304#define BH1750_PM_OPS (&bh1750_pm_ops)
305#else
306#define BH1750_PM_OPS NULL
307#endif
308
309static const struct i2c_device_id bh1750_id[] = {
310 { "bh1710", BH1710 },
311 { "bh1715", BH1750 },
312 { "bh1721", BH1721 },
313 { "bh1750", BH1750 },
314 { "bh1751", BH1750 },
315 { }
316};
317MODULE_DEVICE_TABLE(i2c, bh1750_id);
318
319static struct i2c_driver bh1750_driver = {
320 .driver = {
321 .name = "bh1750",
322 .pm = BH1750_PM_OPS,
323 },
324 .probe = bh1750_probe,
325 .remove = bh1750_remove,
326 .id_table = bh1750_id,
327
328};
329module_i2c_driver(bh1750_driver);
330
331MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
332MODULE_DESCRIPTION("ROHM BH1710/BH1715/BH1721/BH1750/BH1751 als driver");
333MODULE_LICENSE("GPL v2");
334
