Commit | Line | Data |
---|---|---|
cd8d9777 MR |
1 | /* |
2 | * vz89x.c - Support for SGX Sensortech MiCS VZ89X VOC sensors | |
3 | * | |
4 | * Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <linux/module.h> | |
19 | #include <linux/mutex.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/i2c.h> | |
8376882f MR |
22 | #include <linux/of.h> |
23 | #include <linux/of_device.h> | |
cd8d9777 MR |
24 | |
25 | #include <linux/iio/iio.h> | |
26 | #include <linux/iio/sysfs.h> | |
27 | ||
28 | #define VZ89X_REG_MEASUREMENT 0x09 | |
8376882f MR |
29 | #define VZ89X_REG_MEASUREMENT_RD_SIZE 6 |
30 | #define VZ89X_REG_MEASUREMENT_WR_SIZE 3 | |
cd8d9777 MR |
31 | |
32 | #define VZ89X_VOC_CO2_IDX 0 | |
33 | #define VZ89X_VOC_SHORT_IDX 1 | |
34 | #define VZ89X_VOC_TVOC_IDX 2 | |
35 | #define VZ89X_VOC_RESISTANCE_IDX 3 | |
36 | ||
0a735aa0 MR |
37 | #define VZ89TE_REG_MEASUREMENT 0x0c |
38 | #define VZ89TE_REG_MEASUREMENT_RD_SIZE 7 | |
39 | #define VZ89TE_REG_MEASUREMENT_WR_SIZE 6 | |
40 | ||
41 | #define VZ89TE_VOC_TVOC_IDX 0 | |
42 | #define VZ89TE_VOC_CO2_IDX 1 | |
43 | #define VZ89TE_VOC_RESISTANCE_IDX 2 | |
44 | ||
8376882f MR |
45 | enum { |
46 | VZ89X, | |
0a735aa0 | 47 | VZ89TE, |
8376882f MR |
48 | }; |
49 | ||
50 | struct vz89x_chip_data; | |
51 | ||
cd8d9777 MR |
52 | struct vz89x_data { |
53 | struct i2c_client *client; | |
8376882f | 54 | const struct vz89x_chip_data *chip; |
cd8d9777 | 55 | struct mutex lock; |
93e87d73 | 56 | int (*xfer)(struct vz89x_data *data, u8 cmd); |
cd8d9777 | 57 | |
9d1894cd | 58 | bool is_valid; |
93e87d73 | 59 | unsigned long last_update; |
0a735aa0 | 60 | u8 buffer[VZ89TE_REG_MEASUREMENT_RD_SIZE]; |
8376882f MR |
61 | }; |
62 | ||
63 | struct vz89x_chip_data { | |
64 | bool (*valid)(struct vz89x_data *data); | |
65 | const struct iio_chan_spec *channels; | |
66 | u8 num_channels; | |
67 | ||
68 | u8 cmd; | |
69 | u8 read_size; | |
70 | u8 write_size; | |
cd8d9777 MR |
71 | }; |
72 | ||
73 | static const struct iio_chan_spec vz89x_channels[] = { | |
74 | { | |
75 | .type = IIO_CONCENTRATION, | |
76 | .channel2 = IIO_MOD_CO2, | |
77 | .modified = 1, | |
78 | .info_mask_separate = | |
79 | BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW), | |
80 | .address = VZ89X_VOC_CO2_IDX, | |
81 | }, | |
82 | { | |
83 | .type = IIO_CONCENTRATION, | |
84 | .channel2 = IIO_MOD_VOC, | |
85 | .modified = 1, | |
86 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), | |
87 | .address = VZ89X_VOC_SHORT_IDX, | |
88 | .extend_name = "short", | |
89 | }, | |
90 | { | |
91 | .type = IIO_CONCENTRATION, | |
92 | .channel2 = IIO_MOD_VOC, | |
93 | .modified = 1, | |
94 | .info_mask_separate = | |
95 | BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW), | |
96 | .address = VZ89X_VOC_TVOC_IDX, | |
97 | }, | |
98 | { | |
99 | .type = IIO_RESISTANCE, | |
100 | .info_mask_separate = | |
101 | BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), | |
102 | .address = VZ89X_VOC_RESISTANCE_IDX, | |
0a735aa0 MR |
103 | .scan_index = -1, |
104 | .scan_type = { | |
105 | .endianness = IIO_LE, | |
106 | }, | |
107 | }, | |
108 | }; | |
109 | ||
110 | static const struct iio_chan_spec vz89te_channels[] = { | |
111 | { | |
112 | .type = IIO_CONCENTRATION, | |
113 | .channel2 = IIO_MOD_VOC, | |
114 | .modified = 1, | |
115 | .info_mask_separate = | |
116 | BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW), | |
117 | .address = VZ89TE_VOC_TVOC_IDX, | |
118 | }, | |
119 | ||
120 | { | |
121 | .type = IIO_CONCENTRATION, | |
122 | .channel2 = IIO_MOD_CO2, | |
123 | .modified = 1, | |
124 | .info_mask_separate = | |
125 | BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW), | |
126 | .address = VZ89TE_VOC_CO2_IDX, | |
127 | }, | |
128 | { | |
129 | .type = IIO_RESISTANCE, | |
130 | .info_mask_separate = | |
131 | BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), | |
132 | .address = VZ89TE_VOC_RESISTANCE_IDX, | |
133 | .scan_index = -1, | |
134 | .scan_type = { | |
135 | .endianness = IIO_BE, | |
136 | }, | |
cd8d9777 MR |
137 | }, |
138 | }; | |
139 | ||
140 | static IIO_CONST_ATTR(in_concentration_co2_scale, "0.00000698689"); | |
141 | static IIO_CONST_ATTR(in_concentration_voc_scale, "0.00000000436681223"); | |
142 | ||
143 | static struct attribute *vz89x_attributes[] = { | |
144 | &iio_const_attr_in_concentration_co2_scale.dev_attr.attr, | |
145 | &iio_const_attr_in_concentration_voc_scale.dev_attr.attr, | |
146 | NULL, | |
147 | }; | |
148 | ||
149 | static const struct attribute_group vz89x_attrs_group = { | |
150 | .attrs = vz89x_attributes, | |
151 | }; | |
152 | ||
bf23cee6 MR |
153 | /* |
154 | * Chipset sometime updates in the middle of a reading causing it to reset the | |
155 | * data pointer, and causing invalid reading of previous data. | |
156 | * We can check for this by reading MSB of the resistance reading that is | |
157 | * always zero, and by also confirming the VOC_short isn't zero. | |
158 | */ | |
159 | ||
8376882f | 160 | static bool vz89x_measurement_is_valid(struct vz89x_data *data) |
bf23cee6 MR |
161 | { |
162 | if (data->buffer[VZ89X_VOC_SHORT_IDX] == 0) | |
2535cc7a | 163 | return true; |
bf23cee6 | 164 | |
8376882f | 165 | return !!(data->buffer[data->chip->read_size - 1] > 0); |
bf23cee6 MR |
166 | } |
167 | ||
0a735aa0 MR |
168 | /* VZ89TE device has a modified CRC-8 two complement check */ |
169 | static bool vz89te_measurement_is_valid(struct vz89x_data *data) | |
170 | { | |
171 | u8 crc = 0; | |
172 | int i, sum = 0; | |
173 | ||
174 | for (i = 0; i < (data->chip->read_size - 1); i++) { | |
175 | sum = crc + data->buffer[i]; | |
176 | crc = sum; | |
177 | crc += sum / 256; | |
178 | } | |
179 | ||
180 | return !((0xff - crc) == data->buffer[data->chip->read_size - 1]); | |
181 | } | |
182 | ||
93e87d73 | 183 | static int vz89x_i2c_xfer(struct vz89x_data *data, u8 cmd) |
cd8d9777 | 184 | { |
8376882f | 185 | const struct vz89x_chip_data *chip = data->chip; |
93e87d73 MR |
186 | struct i2c_client *client = data->client; |
187 | struct i2c_msg msg[2]; | |
cd8d9777 | 188 | int ret; |
0a735aa0 | 189 | u8 buf[6] = { cmd, 0, 0, 0, 0, 0xf3 }; |
cd8d9777 | 190 | |
93e87d73 MR |
191 | msg[0].addr = client->addr; |
192 | msg[0].flags = client->flags; | |
8376882f | 193 | msg[0].len = chip->write_size; |
93e87d73 MR |
194 | msg[0].buf = (char *) &buf; |
195 | ||
196 | msg[1].addr = client->addr; | |
197 | msg[1].flags = client->flags | I2C_M_RD; | |
8376882f | 198 | msg[1].len = chip->read_size; |
93e87d73 MR |
199 | msg[1].buf = (char *) &data->buffer; |
200 | ||
201 | ret = i2c_transfer(client->adapter, msg, 2); | |
cd8d9777 | 202 | |
93e87d73 MR |
203 | return (ret == 2) ? 0 : ret; |
204 | } | |
205 | ||
206 | static int vz89x_smbus_xfer(struct vz89x_data *data, u8 cmd) | |
207 | { | |
208 | struct i2c_client *client = data->client; | |
209 | int ret; | |
210 | int i; | |
211 | ||
212 | ret = i2c_smbus_write_word_data(client, cmd, 0); | |
cd8d9777 MR |
213 | if (ret < 0) |
214 | return ret; | |
215 | ||
8376882f | 216 | for (i = 0; i < data->chip->read_size; i++) { |
93e87d73 | 217 | ret = i2c_smbus_read_byte(client); |
cd8d9777 MR |
218 | if (ret < 0) |
219 | return ret; | |
220 | data->buffer[i] = ret; | |
221 | } | |
222 | ||
93e87d73 MR |
223 | return 0; |
224 | } | |
225 | ||
226 | static int vz89x_get_measurement(struct vz89x_data *data) | |
227 | { | |
8376882f | 228 | const struct vz89x_chip_data *chip = data->chip; |
93e87d73 MR |
229 | int ret; |
230 | ||
231 | /* sensor can only be polled once a second max per datasheet */ | |
232 | if (!time_after(jiffies, data->last_update + HZ)) | |
9d1894cd MR |
233 | return data->is_valid ? 0 : -EAGAIN; |
234 | ||
235 | data->is_valid = false; | |
236 | data->last_update = jiffies; | |
93e87d73 | 237 | |
8376882f | 238 | ret = data->xfer(data, chip->cmd); |
93e87d73 MR |
239 | if (ret < 0) |
240 | return ret; | |
241 | ||
8376882f | 242 | ret = chip->valid(data); |
bf23cee6 MR |
243 | if (ret) |
244 | return -EAGAIN; | |
245 | ||
9d1894cd | 246 | data->is_valid = true; |
cd8d9777 MR |
247 | |
248 | return 0; | |
249 | } | |
250 | ||
0a735aa0 MR |
251 | static int vz89x_get_resistance_reading(struct vz89x_data *data, |
252 | struct iio_chan_spec const *chan, | |
253 | int *val) | |
cd8d9777 | 254 | { |
0a735aa0 | 255 | u8 *tmp = (u8 *) &data->buffer[chan->address]; |
cd8d9777 | 256 | |
0a735aa0 MR |
257 | switch (chan->scan_type.endianness) { |
258 | case IIO_LE: | |
259 | *val = le32_to_cpup((__le32 *) tmp) & GENMASK(23, 0); | |
260 | break; | |
261 | case IIO_BE: | |
262 | *val = be32_to_cpup((__be32 *) tmp) >> 8; | |
263 | break; | |
264 | default: | |
265 | return -EINVAL; | |
266 | } | |
267 | ||
268 | return 0; | |
cd8d9777 MR |
269 | } |
270 | ||
271 | static int vz89x_read_raw(struct iio_dev *indio_dev, | |
272 | struct iio_chan_spec const *chan, int *val, | |
273 | int *val2, long mask) | |
274 | { | |
275 | struct vz89x_data *data = iio_priv(indio_dev); | |
276 | int ret = -EINVAL; | |
277 | ||
278 | switch (mask) { | |
279 | case IIO_CHAN_INFO_RAW: | |
280 | mutex_lock(&data->lock); | |
281 | ret = vz89x_get_measurement(data); | |
282 | mutex_unlock(&data->lock); | |
283 | ||
284 | if (ret) | |
285 | return ret; | |
286 | ||
0a735aa0 MR |
287 | switch (chan->type) { |
288 | case IIO_CONCENTRATION: | |
cd8d9777 MR |
289 | *val = data->buffer[chan->address]; |
290 | return IIO_VAL_INT; | |
0a735aa0 MR |
291 | case IIO_RESISTANCE: |
292 | ret = vz89x_get_resistance_reading(data, chan, val); | |
293 | if (!ret) | |
294 | return IIO_VAL_INT; | |
295 | break; | |
cd8d9777 MR |
296 | default: |
297 | return -EINVAL; | |
298 | } | |
299 | break; | |
300 | case IIO_CHAN_INFO_SCALE: | |
301 | switch (chan->type) { | |
302 | case IIO_RESISTANCE: | |
303 | *val = 10; | |
304 | return IIO_VAL_INT; | |
305 | default: | |
306 | return -EINVAL; | |
307 | } | |
308 | break; | |
309 | case IIO_CHAN_INFO_OFFSET: | |
0a735aa0 MR |
310 | switch (chan->channel2) { |
311 | case IIO_MOD_CO2: | |
cd8d9777 MR |
312 | *val = 44; |
313 | *val2 = 250000; | |
314 | return IIO_VAL_INT_PLUS_MICRO; | |
0a735aa0 | 315 | case IIO_MOD_VOC: |
cd8d9777 MR |
316 | *val = -13; |
317 | return IIO_VAL_INT; | |
318 | default: | |
319 | return -EINVAL; | |
320 | } | |
321 | } | |
322 | ||
323 | return ret; | |
324 | } | |
325 | ||
326 | static const struct iio_info vz89x_info = { | |
327 | .attrs = &vz89x_attrs_group, | |
328 | .read_raw = vz89x_read_raw, | |
329 | .driver_module = THIS_MODULE, | |
330 | }; | |
331 | ||
8376882f MR |
332 | static const struct vz89x_chip_data vz89x_chips[] = { |
333 | { | |
334 | .valid = vz89x_measurement_is_valid, | |
335 | ||
336 | .cmd = VZ89X_REG_MEASUREMENT, | |
337 | .read_size = VZ89X_REG_MEASUREMENT_RD_SIZE, | |
338 | .write_size = VZ89X_REG_MEASUREMENT_WR_SIZE, | |
339 | ||
340 | .channels = vz89x_channels, | |
341 | .num_channels = ARRAY_SIZE(vz89x_channels), | |
342 | }, | |
0a735aa0 MR |
343 | { |
344 | .valid = vz89te_measurement_is_valid, | |
345 | ||
346 | .cmd = VZ89TE_REG_MEASUREMENT, | |
347 | .read_size = VZ89TE_REG_MEASUREMENT_RD_SIZE, | |
348 | .write_size = VZ89TE_REG_MEASUREMENT_WR_SIZE, | |
349 | ||
350 | .channels = vz89te_channels, | |
351 | .num_channels = ARRAY_SIZE(vz89te_channels), | |
352 | }, | |
8376882f MR |
353 | }; |
354 | ||
355 | static const struct of_device_id vz89x_dt_ids[] = { | |
356 | { .compatible = "sgx,vz89x", .data = (void *) VZ89X }, | |
0a735aa0 | 357 | { .compatible = "sgx,vz89te", .data = (void *) VZ89TE }, |
8376882f MR |
358 | { } |
359 | }; | |
360 | MODULE_DEVICE_TABLE(of, vz89x_dt_ids); | |
361 | ||
cd8d9777 MR |
362 | static int vz89x_probe(struct i2c_client *client, |
363 | const struct i2c_device_id *id) | |
364 | { | |
365 | struct iio_dev *indio_dev; | |
366 | struct vz89x_data *data; | |
8376882f MR |
367 | const struct of_device_id *of_id; |
368 | int chip_id; | |
cd8d9777 | 369 | |
cd8d9777 MR |
370 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
371 | if (!indio_dev) | |
372 | return -ENOMEM; | |
cd8d9777 | 373 | data = iio_priv(indio_dev); |
93e87d73 MR |
374 | |
375 | if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) | |
376 | data->xfer = vz89x_i2c_xfer; | |
377 | else if (i2c_check_functionality(client->adapter, | |
378 | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE)) | |
379 | data->xfer = vz89x_smbus_xfer; | |
380 | else | |
f8d9d3b4 | 381 | return -EOPNOTSUPP; |
93e87d73 | 382 | |
8376882f MR |
383 | of_id = of_match_device(vz89x_dt_ids, &client->dev); |
384 | if (!of_id) | |
385 | chip_id = id->driver_data; | |
386 | else | |
387 | chip_id = (unsigned long)of_id->data; | |
388 | ||
cd8d9777 MR |
389 | i2c_set_clientdata(client, indio_dev); |
390 | data->client = client; | |
8376882f | 391 | data->chip = &vz89x_chips[chip_id]; |
cd8d9777 MR |
392 | data->last_update = jiffies - HZ; |
393 | mutex_init(&data->lock); | |
394 | ||
395 | indio_dev->dev.parent = &client->dev; | |
396 | indio_dev->info = &vz89x_info, | |
397 | indio_dev->name = dev_name(&client->dev); | |
398 | indio_dev->modes = INDIO_DIRECT_MODE; | |
399 | ||
8376882f MR |
400 | indio_dev->channels = data->chip->channels; |
401 | indio_dev->num_channels = data->chip->num_channels; | |
cd8d9777 MR |
402 | |
403 | return devm_iio_device_register(&client->dev, indio_dev); | |
404 | } | |
405 | ||
406 | static const struct i2c_device_id vz89x_id[] = { | |
8376882f | 407 | { "vz89x", VZ89X }, |
0a735aa0 | 408 | { "vz89te", VZ89TE }, |
cd8d9777 MR |
409 | { } |
410 | }; | |
411 | MODULE_DEVICE_TABLE(i2c, vz89x_id); | |
412 | ||
cd8d9777 MR |
413 | static struct i2c_driver vz89x_driver = { |
414 | .driver = { | |
415 | .name = "vz89x", | |
416 | .of_match_table = of_match_ptr(vz89x_dt_ids), | |
417 | }, | |
418 | .probe = vz89x_probe, | |
419 | .id_table = vz89x_id, | |
420 | }; | |
421 | module_i2c_driver(vz89x_driver); | |
422 | ||
423 | MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>"); | |
424 | MODULE_DESCRIPTION("SGX Sensortech MiCS VZ89X VOC sensors"); | |
425 | MODULE_LICENSE("GPL v2"); |