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9#include <linux/module.h>
10#include <linux/mutex.h>
11#include <linux/init.h>
12#include <linux/i2c.h>
13#include <linux/mod_devicetable.h>
14
15#include <linux/iio/iio.h>
16#include <linux/iio/sysfs.h>
17
18#define VZ89X_REG_MEASUREMENT 0x09
19#define VZ89X_REG_MEASUREMENT_RD_SIZE 6
20#define VZ89X_REG_MEASUREMENT_WR_SIZE 3
21
22#define VZ89X_VOC_CO2_IDX 0
23#define VZ89X_VOC_SHORT_IDX 1
24#define VZ89X_VOC_TVOC_IDX 2
25#define VZ89X_VOC_RESISTANCE_IDX 3
26
27#define VZ89TE_REG_MEASUREMENT 0x0c
28#define VZ89TE_REG_MEASUREMENT_RD_SIZE 7
29#define VZ89TE_REG_MEASUREMENT_WR_SIZE 6
30
31#define VZ89TE_VOC_TVOC_IDX 0
32#define VZ89TE_VOC_CO2_IDX 1
33#define VZ89TE_VOC_RESISTANCE_IDX 2
34
35enum {
36 VZ89X,
37 VZ89TE,
38};
39
40struct vz89x_chip_data;
41
42struct vz89x_data {
43 struct i2c_client *client;
44 const struct vz89x_chip_data *chip;
45 struct mutex lock;
46 int (*xfer)(struct vz89x_data *data, u8 cmd);
47
48 bool is_valid;
49 unsigned long last_update;
50 u8 buffer[VZ89TE_REG_MEASUREMENT_RD_SIZE];
51};
52
53struct vz89x_chip_data {
54 bool (*valid)(struct vz89x_data *data);
55 const struct iio_chan_spec *channels;
56 u8 num_channels;
57
58 u8 cmd;
59 u8 read_size;
60 u8 write_size;
61};
62
63static const struct iio_chan_spec vz89x_channels[] = {
64 {
65 .type = IIO_CONCENTRATION,
66 .channel2 = IIO_MOD_CO2,
67 .modified = 1,
68 .info_mask_separate =
69 BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
70 .address = VZ89X_VOC_CO2_IDX,
71 },
72 {
73 .type = IIO_CONCENTRATION,
74 .channel2 = IIO_MOD_VOC,
75 .modified = 1,
76 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
77 .address = VZ89X_VOC_SHORT_IDX,
78 .extend_name = "short",
79 },
80 {
81 .type = IIO_CONCENTRATION,
82 .channel2 = IIO_MOD_VOC,
83 .modified = 1,
84 .info_mask_separate =
85 BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
86 .address = VZ89X_VOC_TVOC_IDX,
87 },
88 {
89 .type = IIO_RESISTANCE,
90 .info_mask_separate =
91 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
92 .address = VZ89X_VOC_RESISTANCE_IDX,
93 .scan_index = -1,
94 .scan_type = {
95 .endianness = IIO_LE,
96 },
97 },
98};
99
100static const struct iio_chan_spec vz89te_channels[] = {
101 {
102 .type = IIO_CONCENTRATION,
103 .channel2 = IIO_MOD_VOC,
104 .modified = 1,
105 .info_mask_separate =
106 BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
107 .address = VZ89TE_VOC_TVOC_IDX,
108 },
109
110 {
111 .type = IIO_CONCENTRATION,
112 .channel2 = IIO_MOD_CO2,
113 .modified = 1,
114 .info_mask_separate =
115 BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
116 .address = VZ89TE_VOC_CO2_IDX,
117 },
118 {
119 .type = IIO_RESISTANCE,
120 .info_mask_separate =
121 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
122 .address = VZ89TE_VOC_RESISTANCE_IDX,
123 .scan_index = -1,
124 .scan_type = {
125 .endianness = IIO_BE,
126 },
127 },
128};
129
130static IIO_CONST_ATTR(in_concentration_co2_scale, "0.00000698689");
131static IIO_CONST_ATTR(in_concentration_voc_scale, "0.00000000436681223");
132
133static struct attribute *vz89x_attributes[] = {
134 &iio_const_attr_in_concentration_co2_scale.dev_attr.attr,
135 &iio_const_attr_in_concentration_voc_scale.dev_attr.attr,
136 NULL,
137};
138
139static const struct attribute_group vz89x_attrs_group = {
140 .attrs = vz89x_attributes,
141};
142
143
144
145
146
147
148
149
150static bool vz89x_measurement_is_valid(struct vz89x_data *data)
151{
152 if (data->buffer[VZ89X_VOC_SHORT_IDX] == 0)
153 return true;
154
155 return !!(data->buffer[data->chip->read_size - 1] > 0);
156}
157
158
159static bool vz89te_measurement_is_valid(struct vz89x_data *data)
160{
161 u8 crc = 0;
162 int i, sum = 0;
163
164 for (i = 0; i < (data->chip->read_size - 1); i++) {
165 sum = crc + data->buffer[i];
166 crc = sum;
167 crc += sum / 256;
168 }
169
170 return !((0xff - crc) == data->buffer[data->chip->read_size - 1]);
171}
172
173static int vz89x_i2c_xfer(struct vz89x_data *data, u8 cmd)
174{
175 const struct vz89x_chip_data *chip = data->chip;
176 struct i2c_client *client = data->client;
177 struct i2c_msg msg[2];
178 int ret;
179 u8 buf[6] = { cmd, 0, 0, 0, 0, 0xf3 };
180
181 msg[0].addr = client->addr;
182 msg[0].flags = client->flags;
183 msg[0].len = chip->write_size;
184 msg[0].buf = (char *) &buf;
185
186 msg[1].addr = client->addr;
187 msg[1].flags = client->flags | I2C_M_RD;
188 msg[1].len = chip->read_size;
189 msg[1].buf = (char *) &data->buffer;
190
191 ret = i2c_transfer(client->adapter, msg, 2);
192
193 return (ret == 2) ? 0 : ret;
194}
195
196static int vz89x_smbus_xfer(struct vz89x_data *data, u8 cmd)
197{
198 struct i2c_client *client = data->client;
199 int ret;
200 int i;
201
202 ret = i2c_smbus_write_word_data(client, cmd, 0);
203 if (ret < 0)
204 return ret;
205
206 for (i = 0; i < data->chip->read_size; i++) {
207 ret = i2c_smbus_read_byte(client);
208 if (ret < 0)
209 return ret;
210 data->buffer[i] = ret;
211 }
212
213 return 0;
214}
215
216static int vz89x_get_measurement(struct vz89x_data *data)
217{
218 const struct vz89x_chip_data *chip = data->chip;
219 int ret;
220
221
222 if (!time_after(jiffies, data->last_update + HZ))
223 return data->is_valid ? 0 : -EAGAIN;
224
225 data->is_valid = false;
226 data->last_update = jiffies;
227
228 ret = data->xfer(data, chip->cmd);
229 if (ret < 0)
230 return ret;
231
232 ret = chip->valid(data);
233 if (ret)
234 return -EAGAIN;
235
236 data->is_valid = true;
237
238 return 0;
239}
240
241static int vz89x_get_resistance_reading(struct vz89x_data *data,
242 struct iio_chan_spec const *chan,
243 int *val)
244{
245 u8 *tmp = (u8 *) &data->buffer[chan->address];
246
247 switch (chan->scan_type.endianness) {
248 case IIO_LE:
249 *val = le32_to_cpup((__le32 *) tmp) & GENMASK(23, 0);
250 break;
251 case IIO_BE:
252 *val = be32_to_cpup((__be32 *) tmp) >> 8;
253 break;
254 default:
255 return -EINVAL;
256 }
257
258 return 0;
259}
260
261static int vz89x_read_raw(struct iio_dev *indio_dev,
262 struct iio_chan_spec const *chan, int *val,
263 int *val2, long mask)
264{
265 struct vz89x_data *data = iio_priv(indio_dev);
266 int ret = -EINVAL;
267
268 switch (mask) {
269 case IIO_CHAN_INFO_RAW:
270 mutex_lock(&data->lock);
271 ret = vz89x_get_measurement(data);
272 mutex_unlock(&data->lock);
273
274 if (ret)
275 return ret;
276
277 switch (chan->type) {
278 case IIO_CONCENTRATION:
279 *val = data->buffer[chan->address];
280 return IIO_VAL_INT;
281 case IIO_RESISTANCE:
282 ret = vz89x_get_resistance_reading(data, chan, val);
283 if (!ret)
284 return IIO_VAL_INT;
285 break;
286 default:
287 return -EINVAL;
288 }
289 break;
290 case IIO_CHAN_INFO_SCALE:
291 switch (chan->type) {
292 case IIO_RESISTANCE:
293 *val = 10;
294 return IIO_VAL_INT;
295 default:
296 return -EINVAL;
297 }
298 break;
299 case IIO_CHAN_INFO_OFFSET:
300 switch (chan->channel2) {
301 case IIO_MOD_CO2:
302 *val = 44;
303 *val2 = 250000;
304 return IIO_VAL_INT_PLUS_MICRO;
305 case IIO_MOD_VOC:
306 *val = -13;
307 return IIO_VAL_INT;
308 default:
309 return -EINVAL;
310 }
311 }
312
313 return ret;
314}
315
316static const struct iio_info vz89x_info = {
317 .attrs = &vz89x_attrs_group,
318 .read_raw = vz89x_read_raw,
319};
320
321static const struct vz89x_chip_data vz89x_chips[] = {
322 {
323 .valid = vz89x_measurement_is_valid,
324
325 .cmd = VZ89X_REG_MEASUREMENT,
326 .read_size = VZ89X_REG_MEASUREMENT_RD_SIZE,
327 .write_size = VZ89X_REG_MEASUREMENT_WR_SIZE,
328
329 .channels = vz89x_channels,
330 .num_channels = ARRAY_SIZE(vz89x_channels),
331 },
332 {
333 .valid = vz89te_measurement_is_valid,
334
335 .cmd = VZ89TE_REG_MEASUREMENT,
336 .read_size = VZ89TE_REG_MEASUREMENT_RD_SIZE,
337 .write_size = VZ89TE_REG_MEASUREMENT_WR_SIZE,
338
339 .channels = vz89te_channels,
340 .num_channels = ARRAY_SIZE(vz89te_channels),
341 },
342};
343
344static const struct of_device_id vz89x_dt_ids[] = {
345 { .compatible = "sgx,vz89x", .data = (void *) VZ89X },
346 { .compatible = "sgx,vz89te", .data = (void *) VZ89TE },
347 { }
348};
349MODULE_DEVICE_TABLE(of, vz89x_dt_ids);
350
351static int vz89x_probe(struct i2c_client *client,
352 const struct i2c_device_id *id)
353{
354 struct device *dev = &client->dev;
355 struct iio_dev *indio_dev;
356 struct vz89x_data *data;
357 int chip_id;
358
359 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
360 if (!indio_dev)
361 return -ENOMEM;
362 data = iio_priv(indio_dev);
363
364 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
365 data->xfer = vz89x_i2c_xfer;
366 else if (i2c_check_functionality(client->adapter,
367 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
368 data->xfer = vz89x_smbus_xfer;
369 else
370 return -EOPNOTSUPP;
371
372 if (!dev_fwnode(dev))
373 chip_id = id->driver_data;
374 else
375 chip_id = (unsigned long)device_get_match_data(dev);
376
377 i2c_set_clientdata(client, indio_dev);
378 data->client = client;
379 data->chip = &vz89x_chips[chip_id];
380 data->last_update = jiffies - HZ;
381 mutex_init(&data->lock);
382
383 indio_dev->info = &vz89x_info;
384 indio_dev->name = dev_name(dev);
385 indio_dev->modes = INDIO_DIRECT_MODE;
386
387 indio_dev->channels = data->chip->channels;
388 indio_dev->num_channels = data->chip->num_channels;
389
390 return devm_iio_device_register(dev, indio_dev);
391}
392
393static const struct i2c_device_id vz89x_id[] = {
394 { "vz89x", VZ89X },
395 { "vz89te", VZ89TE },
396 { }
397};
398MODULE_DEVICE_TABLE(i2c, vz89x_id);
399
400static struct i2c_driver vz89x_driver = {
401 .driver = {
402 .name = "vz89x",
403 .of_match_table = vz89x_dt_ids,
404 },
405 .probe = vz89x_probe,
406 .id_table = vz89x_id,
407};
408module_i2c_driver(vz89x_driver);
409
410MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
411MODULE_DESCRIPTION("SGX Sensortech MiCS VZ89X VOC sensors");
412MODULE_LICENSE("GPL v2");
413
