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13#include <linux/module.h>
14#include <linux/i2c.h>
15#include <linux/iio/iio.h>
16#include <linux/iio/sysfs.h>
17#include <linux/delay.h>
18#include <linux/util_macros.h>
19#include <linux/acpi.h>
20
21
22#define HP206C_CMD_SOFT_RST 0x06
23
24#define HP206C_CMD_ADC_CVT 0x40
25
26#define HP206C_CMD_ADC_CVT_OSR_4096 0x00
27#define HP206C_CMD_ADC_CVT_OSR_2048 0x04
28#define HP206C_CMD_ADC_CVT_OSR_1024 0x08
29#define HP206C_CMD_ADC_CVT_OSR_512 0x0c
30#define HP206C_CMD_ADC_CVT_OSR_256 0x10
31#define HP206C_CMD_ADC_CVT_OSR_128 0x14
32
33#define HP206C_CMD_ADC_CVT_CHNL_PT 0x00
34#define HP206C_CMD_ADC_CVT_CHNL_T 0x02
35
36#define HP206C_CMD_READ_P 0x30
37#define HP206C_CMD_READ_T 0x32
38
39#define HP206C_CMD_READ_REG 0x80
40#define HP206C_CMD_WRITE_REG 0xc0
41
42#define HP206C_REG_INT_EN 0x0b
43#define HP206C_REG_INT_CFG 0x0c
44
45#define HP206C_REG_INT_SRC 0x0d
46#define HP206C_FLAG_DEV_RDY 0x40
47
48#define HP206C_REG_PARA 0x0f
49#define HP206C_FLAG_CMPS_EN 0x80
50
51
52#define HP206C_MAX_DEV_RDY_WAIT_COUNT 20
53#define HP206C_DEV_RDY_WAIT_US 20000
54
55struct hp206c_data {
56 struct mutex mutex;
57 struct i2c_client *client;
58 int temp_osr_index;
59 int pres_osr_index;
60};
61
62struct hp206c_osr_setting {
63 u8 osr_mask;
64 unsigned int temp_conv_time_us;
65 unsigned int pres_conv_time_us;
66};
67
68
69static const struct hp206c_osr_setting hp206c_osr_settings[] = {
70 { HP206C_CMD_ADC_CVT_OSR_4096, 65600, 131100 },
71 { HP206C_CMD_ADC_CVT_OSR_2048, 32800, 65600 },
72 { HP206C_CMD_ADC_CVT_OSR_1024, 16400, 32800 },
73 { HP206C_CMD_ADC_CVT_OSR_512, 8200, 16400 },
74 { HP206C_CMD_ADC_CVT_OSR_256, 4100, 8200 },
75 { HP206C_CMD_ADC_CVT_OSR_128, 2100, 4100 },
76};
77static const int hp206c_osr_rates[] = { 4096, 2048, 1024, 512, 256, 128 };
78static const char hp206c_osr_rates_str[] = "4096 2048 1024 512 256 128";
79
80static inline int hp206c_read_reg(struct i2c_client *client, u8 reg)
81{
82 return i2c_smbus_read_byte_data(client, HP206C_CMD_READ_REG | reg);
83}
84
85static inline int hp206c_write_reg(struct i2c_client *client, u8 reg, u8 val)
86{
87 return i2c_smbus_write_byte_data(client,
88 HP206C_CMD_WRITE_REG | reg, val);
89}
90
91static int hp206c_read_20bit(struct i2c_client *client, u8 cmd)
92{
93 int ret;
94 u8 values[3];
95
96 ret = i2c_smbus_read_i2c_block_data(client, cmd, 3, values);
97 if (ret < 0)
98 return ret;
99 if (ret != 3)
100 return -EIO;
101 return ((values[0] & 0xF) << 16) | (values[1] << 8) | (values[2]);
102}
103
104
105static int hp206c_wait_dev_rdy(struct iio_dev *indio_dev)
106{
107 int ret;
108 int count = 0;
109 struct hp206c_data *data = iio_priv(indio_dev);
110 struct i2c_client *client = data->client;
111
112 while (++count <= HP206C_MAX_DEV_RDY_WAIT_COUNT) {
113 ret = hp206c_read_reg(client, HP206C_REG_INT_SRC);
114 if (ret < 0) {
115 dev_err(&indio_dev->dev, "Failed READ_REG INT_SRC: %d\n", ret);
116 return ret;
117 }
118 if (ret & HP206C_FLAG_DEV_RDY)
119 return 0;
120 usleep_range(HP206C_DEV_RDY_WAIT_US, HP206C_DEV_RDY_WAIT_US * 3 / 2);
121 }
122 return -ETIMEDOUT;
123}
124
125static int hp206c_set_compensation(struct i2c_client *client, bool enabled)
126{
127 int val;
128
129 val = hp206c_read_reg(client, HP206C_REG_PARA);
130 if (val < 0)
131 return val;
132 if (enabled)
133 val |= HP206C_FLAG_CMPS_EN;
134 else
135 val &= ~HP206C_FLAG_CMPS_EN;
136
137 return hp206c_write_reg(client, HP206C_REG_PARA, val);
138}
139
140
141static int hp206c_soft_reset(struct iio_dev *indio_dev)
142{
143 int ret;
144 struct hp206c_data *data = iio_priv(indio_dev);
145 struct i2c_client *client = data->client;
146
147 ret = i2c_smbus_write_byte(client, HP206C_CMD_SOFT_RST);
148 if (ret) {
149 dev_err(&client->dev, "Failed to reset device: %d\n", ret);
150 return ret;
151 }
152
153 usleep_range(400, 600);
154
155 ret = hp206c_wait_dev_rdy(indio_dev);
156 if (ret) {
157 dev_err(&client->dev, "Device not ready after soft reset: %d\n", ret);
158 return ret;
159 }
160
161 ret = hp206c_set_compensation(client, true);
162 if (ret)
163 dev_err(&client->dev, "Failed to enable compensation: %d\n", ret);
164 return ret;
165}
166
167static int hp206c_conv_and_read(struct iio_dev *indio_dev,
168 u8 conv_cmd, u8 read_cmd,
169 unsigned int sleep_us)
170{
171 int ret;
172 struct hp206c_data *data = iio_priv(indio_dev);
173 struct i2c_client *client = data->client;
174
175 ret = hp206c_wait_dev_rdy(indio_dev);
176 if (ret < 0) {
177 dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);
178 return ret;
179 }
180
181 ret = i2c_smbus_write_byte(client, conv_cmd);
182 if (ret < 0) {
183 dev_err(&indio_dev->dev, "Failed convert: %d\n", ret);
184 return ret;
185 }
186
187 usleep_range(sleep_us, sleep_us * 3 / 2);
188
189 ret = hp206c_wait_dev_rdy(indio_dev);
190 if (ret < 0) {
191 dev_err(&indio_dev->dev, "Device not ready: %d\n", ret);
192 return ret;
193 }
194
195 ret = hp206c_read_20bit(client, read_cmd);
196 if (ret < 0)
197 dev_err(&indio_dev->dev, "Failed read: %d\n", ret);
198
199 return ret;
200}
201
202static int hp206c_read_raw(struct iio_dev *indio_dev,
203 struct iio_chan_spec const *chan, int *val,
204 int *val2, long mask)
205{
206 int ret;
207 struct hp206c_data *data = iio_priv(indio_dev);
208 const struct hp206c_osr_setting *osr_setting;
209 u8 conv_cmd;
210
211 mutex_lock(&data->mutex);
212
213 switch (mask) {
214 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
215 switch (chan->type) {
216 case IIO_TEMP:
217 *val = hp206c_osr_rates[data->temp_osr_index];
218 ret = IIO_VAL_INT;
219 break;
220
221 case IIO_PRESSURE:
222 *val = hp206c_osr_rates[data->pres_osr_index];
223 ret = IIO_VAL_INT;
224 break;
225 default:
226 ret = -EINVAL;
227 }
228 break;
229
230 case IIO_CHAN_INFO_RAW:
231 switch (chan->type) {
232 case IIO_TEMP:
233 osr_setting = &hp206c_osr_settings[data->temp_osr_index];
234 conv_cmd = HP206C_CMD_ADC_CVT |
235 osr_setting->osr_mask |
236 HP206C_CMD_ADC_CVT_CHNL_T;
237 ret = hp206c_conv_and_read(indio_dev,
238 conv_cmd,
239 HP206C_CMD_READ_T,
240 osr_setting->temp_conv_time_us);
241 if (ret >= 0) {
242
243
244
245 *val = sign_extend32(ret, 19);
246 ret = IIO_VAL_INT;
247 }
248 break;
249
250 case IIO_PRESSURE:
251 osr_setting = &hp206c_osr_settings[data->pres_osr_index];
252 conv_cmd = HP206C_CMD_ADC_CVT |
253 osr_setting->osr_mask |
254 HP206C_CMD_ADC_CVT_CHNL_PT;
255 ret = hp206c_conv_and_read(indio_dev,
256 conv_cmd,
257 HP206C_CMD_READ_P,
258 osr_setting->pres_conv_time_us);
259 if (ret >= 0) {
260 *val = ret;
261 ret = IIO_VAL_INT;
262 }
263 break;
264 default:
265 ret = -EINVAL;
266 }
267 break;
268
269 case IIO_CHAN_INFO_SCALE:
270 switch (chan->type) {
271 case IIO_TEMP:
272 *val = 0;
273 *val2 = 10000;
274 ret = IIO_VAL_INT_PLUS_MICRO;
275 break;
276
277 case IIO_PRESSURE:
278 *val = 0;
279 *val2 = 1000;
280 ret = IIO_VAL_INT_PLUS_MICRO;
281 break;
282 default:
283 ret = -EINVAL;
284 }
285 break;
286
287 default:
288 ret = -EINVAL;
289 }
290
291 mutex_unlock(&data->mutex);
292 return ret;
293}
294
295static int hp206c_write_raw(struct iio_dev *indio_dev,
296 struct iio_chan_spec const *chan,
297 int val, int val2, long mask)
298{
299 int ret = 0;
300 struct hp206c_data *data = iio_priv(indio_dev);
301
302 if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
303 return -EINVAL;
304 mutex_lock(&data->mutex);
305 switch (chan->type) {
306 case IIO_TEMP:
307 data->temp_osr_index = find_closest_descending(val,
308 hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));
309 break;
310 case IIO_PRESSURE:
311 data->pres_osr_index = find_closest_descending(val,
312 hp206c_osr_rates, ARRAY_SIZE(hp206c_osr_rates));
313 break;
314 default:
315 ret = -EINVAL;
316 }
317 mutex_unlock(&data->mutex);
318 return ret;
319}
320
321static const struct iio_chan_spec hp206c_channels[] = {
322 {
323 .type = IIO_TEMP,
324 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
325 BIT(IIO_CHAN_INFO_SCALE) |
326 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
327 },
328 {
329 .type = IIO_PRESSURE,
330 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
331 BIT(IIO_CHAN_INFO_SCALE) |
332 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
333 }
334};
335
336static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(hp206c_osr_rates_str);
337
338static struct attribute *hp206c_attributes[] = {
339 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
340 NULL,
341};
342
343static const struct attribute_group hp206c_attribute_group = {
344 .attrs = hp206c_attributes,
345};
346
347static const struct iio_info hp206c_info = {
348 .attrs = &hp206c_attribute_group,
349 .read_raw = hp206c_read_raw,
350 .write_raw = hp206c_write_raw,
351};
352
353static int hp206c_probe(struct i2c_client *client,
354 const struct i2c_device_id *id)
355{
356 struct iio_dev *indio_dev;
357 struct hp206c_data *data;
358 int ret;
359
360 if (!i2c_check_functionality(client->adapter,
361 I2C_FUNC_SMBUS_BYTE |
362 I2C_FUNC_SMBUS_BYTE_DATA |
363 I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
364 dev_err(&client->dev, "Adapter does not support "
365 "all required i2c functionality\n");
366 return -ENODEV;
367 }
368
369 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
370 if (!indio_dev)
371 return -ENOMEM;
372
373 data = iio_priv(indio_dev);
374 data->client = client;
375 mutex_init(&data->mutex);
376
377 indio_dev->info = &hp206c_info;
378 indio_dev->name = id->name;
379 indio_dev->dev.parent = &client->dev;
380 indio_dev->modes = INDIO_DIRECT_MODE;
381 indio_dev->channels = hp206c_channels;
382 indio_dev->num_channels = ARRAY_SIZE(hp206c_channels);
383
384 i2c_set_clientdata(client, indio_dev);
385
386
387 ret = hp206c_soft_reset(indio_dev);
388 if (ret) {
389 dev_err(&client->dev, "Failed to reset on startup: %d\n", ret);
390 return -ENODEV;
391 }
392
393 return devm_iio_device_register(&client->dev, indio_dev);
394}
395
396static const struct i2c_device_id hp206c_id[] = {
397 {"hp206c"},
398 {}
399};
400MODULE_DEVICE_TABLE(i2c, hp206c_id);
401
402#ifdef CONFIG_ACPI
403static const struct acpi_device_id hp206c_acpi_match[] = {
404 {"HOP206C", 0},
405 { },
406};
407MODULE_DEVICE_TABLE(acpi, hp206c_acpi_match);
408#endif
409
410static struct i2c_driver hp206c_driver = {
411 .probe = hp206c_probe,
412 .id_table = hp206c_id,
413 .driver = {
414 .name = "hp206c",
415 .acpi_match_table = ACPI_PTR(hp206c_acpi_match),
416 },
417};
418
419module_i2c_driver(hp206c_driver);
420
421MODULE_DESCRIPTION("HOPERF HP206C precision barometer and altimeter sensor");
422MODULE_AUTHOR("Leonard Crestez <leonard.crestez@intel.com>");
423MODULE_LICENSE("GPL v2");
424
