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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/of.h>
14#include <linux/of_device.h>
15
16#include <linux/iio/iio.h>
17#include <linux/iio/sysfs.h>
18
19#define VZ89X_REG_MEASUREMENT 0x09
20#define VZ89X_REG_MEASUREMENT_RD_SIZE 6
21#define VZ89X_REG_MEASUREMENT_WR_SIZE 3
22
23#define VZ89X_VOC_CO2_IDX 0
24#define VZ89X_VOC_SHORT_IDX 1
25#define VZ89X_VOC_TVOC_IDX 2
26#define VZ89X_VOC_RESISTANCE_IDX 3
27
28#define VZ89TE_REG_MEASUREMENT 0x0c
29#define VZ89TE_REG_MEASUREMENT_RD_SIZE 7
30#define VZ89TE_REG_MEASUREMENT_WR_SIZE 6
31
32#define VZ89TE_VOC_TVOC_IDX 0
33#define VZ89TE_VOC_CO2_IDX 1
34#define VZ89TE_VOC_RESISTANCE_IDX 2
35
36enum {
37 VZ89X,
38 VZ89TE,
39};
40
41struct vz89x_chip_data;
42
43struct vz89x_data {
44 struct i2c_client *client;
45 const struct vz89x_chip_data *chip;
46 struct mutex lock;
47 int (*xfer)(struct vz89x_data *data, u8 cmd);
48
49 bool is_valid;
50 unsigned long last_update;
51 u8 buffer[VZ89TE_REG_MEASUREMENT_RD_SIZE];
52};
53
54struct vz89x_chip_data {
55 bool (*valid)(struct vz89x_data *data);
56 const struct iio_chan_spec *channels;
57 u8 num_channels;
58
59 u8 cmd;
60 u8 read_size;
61 u8 write_size;
62};
63
64static const struct iio_chan_spec vz89x_channels[] = {
65 {
66 .type = IIO_CONCENTRATION,
67 .channel2 = IIO_MOD_CO2,
68 .modified = 1,
69 .info_mask_separate =
70 BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
71 .address = VZ89X_VOC_CO2_IDX,
72 },
73 {
74 .type = IIO_CONCENTRATION,
75 .channel2 = IIO_MOD_VOC,
76 .modified = 1,
77 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
78 .address = VZ89X_VOC_SHORT_IDX,
79 .extend_name = "short",
80 },
81 {
82 .type = IIO_CONCENTRATION,
83 .channel2 = IIO_MOD_VOC,
84 .modified = 1,
85 .info_mask_separate =
86 BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
87 .address = VZ89X_VOC_TVOC_IDX,
88 },
89 {
90 .type = IIO_RESISTANCE,
91 .info_mask_separate =
92 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
93 .address = VZ89X_VOC_RESISTANCE_IDX,
94 .scan_index = -1,
95 .scan_type = {
96 .endianness = IIO_LE,
97 },
98 },
99};
100
101static const struct iio_chan_spec vz89te_channels[] = {
102 {
103 .type = IIO_CONCENTRATION,
104 .channel2 = IIO_MOD_VOC,
105 .modified = 1,
106 .info_mask_separate =
107 BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
108 .address = VZ89TE_VOC_TVOC_IDX,
109 },
110
111 {
112 .type = IIO_CONCENTRATION,
113 .channel2 = IIO_MOD_CO2,
114 .modified = 1,
115 .info_mask_separate =
116 BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_RAW),
117 .address = VZ89TE_VOC_CO2_IDX,
118 },
119 {
120 .type = IIO_RESISTANCE,
121 .info_mask_separate =
122 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
123 .address = VZ89TE_VOC_RESISTANCE_IDX,
124 .scan_index = -1,
125 .scan_type = {
126 .endianness = IIO_BE,
127 },
128 },
129};
130
131static IIO_CONST_ATTR(in_concentration_co2_scale, "0.00000698689");
132static IIO_CONST_ATTR(in_concentration_voc_scale, "0.00000000436681223");
133
134static struct attribute *vz89x_attributes[] = {
135 &iio_const_attr_in_concentration_co2_scale.dev_attr.attr,
136 &iio_const_attr_in_concentration_voc_scale.dev_attr.attr,
137 NULL,
138};
139
140static const struct attribute_group vz89x_attrs_group = {
141 .attrs = vz89x_attributes,
142};
143
144
145
146
147
148
149
150
151static bool vz89x_measurement_is_valid(struct vz89x_data *data)
152{
153 if (data->buffer[VZ89X_VOC_SHORT_IDX] == 0)
154 return true;
155
156 return !!(data->buffer[data->chip->read_size - 1] > 0);
157}
158
159
160static bool vz89te_measurement_is_valid(struct vz89x_data *data)
161{
162 u8 crc = 0;
163 int i, sum = 0;
164
165 for (i = 0; i < (data->chip->read_size - 1); i++) {
166 sum = crc + data->buffer[i];
167 crc = sum;
168 crc += sum / 256;
169 }
170
171 return !((0xff - crc) == data->buffer[data->chip->read_size - 1]);
172}
173
174static int vz89x_i2c_xfer(struct vz89x_data *data, u8 cmd)
175{
176 const struct vz89x_chip_data *chip = data->chip;
177 struct i2c_client *client = data->client;
178 struct i2c_msg msg[2];
179 int ret;
180 u8 buf[6] = { cmd, 0, 0, 0, 0, 0xf3 };
181
182 msg[0].addr = client->addr;
183 msg[0].flags = client->flags;
184 msg[0].len = chip->write_size;
185 msg[0].buf = (char *) &buf;
186
187 msg[1].addr = client->addr;
188 msg[1].flags = client->flags | I2C_M_RD;
189 msg[1].len = chip->read_size;
190 msg[1].buf = (char *) &data->buffer;
191
192 ret = i2c_transfer(client->adapter, msg, 2);
193
194 return (ret == 2) ? 0 : ret;
195}
196
197static int vz89x_smbus_xfer(struct vz89x_data *data, u8 cmd)
198{
199 struct i2c_client *client = data->client;
200 int ret;
201 int i;
202
203 ret = i2c_smbus_write_word_data(client, cmd, 0);
204 if (ret < 0)
205 return ret;
206
207 for (i = 0; i < data->chip->read_size; i++) {
208 ret = i2c_smbus_read_byte(client);
209 if (ret < 0)
210 return ret;
211 data->buffer[i] = ret;
212 }
213
214 return 0;
215}
216
217static int vz89x_get_measurement(struct vz89x_data *data)
218{
219 const struct vz89x_chip_data *chip = data->chip;
220 int ret;
221
222
223 if (!time_after(jiffies, data->last_update + HZ))
224 return data->is_valid ? 0 : -EAGAIN;
225
226 data->is_valid = false;
227 data->last_update = jiffies;
228
229 ret = data->xfer(data, chip->cmd);
230 if (ret < 0)
231 return ret;
232
233 ret = chip->valid(data);
234 if (ret)
235 return -EAGAIN;
236
237 data->is_valid = true;
238
239 return 0;
240}
241
242static int vz89x_get_resistance_reading(struct vz89x_data *data,
243 struct iio_chan_spec const *chan,
244 int *val)
245{
246 u8 *tmp = (u8 *) &data->buffer[chan->address];
247
248 switch (chan->scan_type.endianness) {
249 case IIO_LE:
250 *val = le32_to_cpup((__le32 *) tmp) & GENMASK(23, 0);
251 break;
252 case IIO_BE:
253 *val = be32_to_cpup((__be32 *) tmp) >> 8;
254 break;
255 default:
256 return -EINVAL;
257 }
258
259 return 0;
260}
261
262static int vz89x_read_raw(struct iio_dev *indio_dev,
263 struct iio_chan_spec const *chan, int *val,
264 int *val2, long mask)
265{
266 struct vz89x_data *data = iio_priv(indio_dev);
267 int ret = -EINVAL;
268
269 switch (mask) {
270 case IIO_CHAN_INFO_RAW:
271 mutex_lock(&data->lock);
272 ret = vz89x_get_measurement(data);
273 mutex_unlock(&data->lock);
274
275 if (ret)
276 return ret;
277
278 switch (chan->type) {
279 case IIO_CONCENTRATION:
280 *val = data->buffer[chan->address];
281 return IIO_VAL_INT;
282 case IIO_RESISTANCE:
283 ret = vz89x_get_resistance_reading(data, chan, val);
284 if (!ret)
285 return IIO_VAL_INT;
286 break;
287 default:
288 return -EINVAL;
289 }
290 break;
291 case IIO_CHAN_INFO_SCALE:
292 switch (chan->type) {
293 case IIO_RESISTANCE:
294 *val = 10;
295 return IIO_VAL_INT;
296 default:
297 return -EINVAL;
298 }
299 break;
300 case IIO_CHAN_INFO_OFFSET:
301 switch (chan->channel2) {
302 case IIO_MOD_CO2:
303 *val = 44;
304 *val2 = 250000;
305 return IIO_VAL_INT_PLUS_MICRO;
306 case IIO_MOD_VOC:
307 *val = -13;
308 return IIO_VAL_INT;
309 default:
310 return -EINVAL;
311 }
312 }
313
314 return ret;
315}
316
317static const struct iio_info vz89x_info = {
318 .attrs = &vz89x_attrs_group,
319 .read_raw = vz89x_read_raw,
320};
321
322static const struct vz89x_chip_data vz89x_chips[] = {
323 {
324 .valid = vz89x_measurement_is_valid,
325
326 .cmd = VZ89X_REG_MEASUREMENT,
327 .read_size = VZ89X_REG_MEASUREMENT_RD_SIZE,
328 .write_size = VZ89X_REG_MEASUREMENT_WR_SIZE,
329
330 .channels = vz89x_channels,
331 .num_channels = ARRAY_SIZE(vz89x_channels),
332 },
333 {
334 .valid = vz89te_measurement_is_valid,
335
336 .cmd = VZ89TE_REG_MEASUREMENT,
337 .read_size = VZ89TE_REG_MEASUREMENT_RD_SIZE,
338 .write_size = VZ89TE_REG_MEASUREMENT_WR_SIZE,
339
340 .channels = vz89te_channels,
341 .num_channels = ARRAY_SIZE(vz89te_channels),
342 },
343};
344
345static const struct of_device_id vz89x_dt_ids[] = {
346 { .compatible = "sgx,vz89x", .data = (void *) VZ89X },
347 { .compatible = "sgx,vz89te", .data = (void *) VZ89TE },
348 { }
349};
350MODULE_DEVICE_TABLE(of, vz89x_dt_ids);
351
352static int vz89x_probe(struct i2c_client *client,
353 const struct i2c_device_id *id)
354{
355 struct iio_dev *indio_dev;
356 struct vz89x_data *data;
357 const struct of_device_id *of_id;
358 int chip_id;
359
360 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
361 if (!indio_dev)
362 return -ENOMEM;
363 data = iio_priv(indio_dev);
364
365 if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
366 data->xfer = vz89x_i2c_xfer;
367 else if (i2c_check_functionality(client->adapter,
368 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE))
369 data->xfer = vz89x_smbus_xfer;
370 else
371 return -EOPNOTSUPP;
372
373 of_id = of_match_device(vz89x_dt_ids, &client->dev);
374 if (!of_id)
375 chip_id = id->driver_data;
376 else
377 chip_id = (unsigned long)of_id->data;
378
379 i2c_set_clientdata(client, indio_dev);
380 data->client = client;
381 data->chip = &vz89x_chips[chip_id];
382 data->last_update = jiffies - HZ;
383 mutex_init(&data->lock);
384
385 indio_dev->dev.parent = &client->dev;
386 indio_dev->info = &vz89x_info;
387 indio_dev->name = dev_name(&client->dev);
388 indio_dev->modes = INDIO_DIRECT_MODE;
389
390 indio_dev->channels = data->chip->channels;
391 indio_dev->num_channels = data->chip->num_channels;
392
393 return devm_iio_device_register(&client->dev, indio_dev);
394}
395
396static const struct i2c_device_id vz89x_id[] = {
397 { "vz89x", VZ89X },
398 { "vz89te", VZ89TE },
399 { }
400};
401MODULE_DEVICE_TABLE(i2c, vz89x_id);
402
403static struct i2c_driver vz89x_driver = {
404 .driver = {
405 .name = "vz89x",
406 .of_match_table = of_match_ptr(vz89x_dt_ids),
407 },
408 .probe = vz89x_probe,
409 .id_table = vz89x_id,
410};
411module_i2c_driver(vz89x_driver);
412
413MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
414MODULE_DESCRIPTION("SGX Sensortech MiCS VZ89X VOC sensors");
415MODULE_LICENSE("GPL v2");
416
