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b3c590ce MR |
1 | /* |
2 | * max30102.c - Support for MAX30102 heart rate and pulse oximeter sensor | |
3 | * | |
4 | * Copyright (C) 2017 Matt Ranostay <matt@ranostay.consulting> | |
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 | * TODO: proximity power saving feature | |
17 | */ | |
18 | ||
19 | #include <linux/module.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/interrupt.h> | |
22 | #include <linux/delay.h> | |
23 | #include <linux/err.h> | |
24 | #include <linux/irq.h> | |
25 | #include <linux/i2c.h> | |
26 | #include <linux/mutex.h> | |
27 | #include <linux/of.h> | |
28 | #include <linux/regmap.h> | |
29 | #include <linux/iio/iio.h> | |
30 | #include <linux/iio/buffer.h> | |
31 | #include <linux/iio/kfifo_buf.h> | |
32 | ||
33 | #define MAX30102_REGMAP_NAME "max30102_regmap" | |
34 | #define MAX30102_DRV_NAME "max30102" | |
35 | ||
36 | #define MAX30102_REG_INT_STATUS 0x00 | |
37 | #define MAX30102_REG_INT_STATUS_PWR_RDY BIT(0) | |
38 | #define MAX30102_REG_INT_STATUS_PROX_INT BIT(4) | |
39 | #define MAX30102_REG_INT_STATUS_ALC_OVF BIT(5) | |
40 | #define MAX30102_REG_INT_STATUS_PPG_RDY BIT(6) | |
41 | #define MAX30102_REG_INT_STATUS_FIFO_RDY BIT(7) | |
42 | ||
43 | #define MAX30102_REG_INT_ENABLE 0x02 | |
44 | #define MAX30102_REG_INT_ENABLE_PROX_INT_EN BIT(4) | |
45 | #define MAX30102_REG_INT_ENABLE_ALC_OVF_EN BIT(5) | |
46 | #define MAX30102_REG_INT_ENABLE_PPG_EN BIT(6) | |
47 | #define MAX30102_REG_INT_ENABLE_FIFO_EN BIT(7) | |
48 | #define MAX30102_REG_INT_ENABLE_MASK 0xf0 | |
49 | #define MAX30102_REG_INT_ENABLE_MASK_SHIFT 4 | |
50 | ||
51 | #define MAX30102_REG_FIFO_WR_PTR 0x04 | |
52 | #define MAX30102_REG_FIFO_OVR_CTR 0x05 | |
53 | #define MAX30102_REG_FIFO_RD_PTR 0x06 | |
54 | #define MAX30102_REG_FIFO_DATA 0x07 | |
55 | #define MAX30102_REG_FIFO_DATA_ENTRY_LEN 6 | |
56 | ||
57 | #define MAX30102_REG_FIFO_CONFIG 0x08 | |
58 | #define MAX30102_REG_FIFO_CONFIG_AVG_4SAMPLES BIT(1) | |
59 | #define MAX30102_REG_FIFO_CONFIG_AVG_SHIFT 5 | |
60 | #define MAX30102_REG_FIFO_CONFIG_AFULL BIT(0) | |
61 | ||
62 | #define MAX30102_REG_MODE_CONFIG 0x09 | |
63 | #define MAX30102_REG_MODE_CONFIG_MODE_SPO2_EN BIT(0) | |
64 | #define MAX30102_REG_MODE_CONFIG_MODE_HR_EN BIT(1) | |
65 | #define MAX30102_REG_MODE_CONFIG_MODE_MASK 0x03 | |
66 | #define MAX30102_REG_MODE_CONFIG_PWR BIT(7) | |
67 | ||
68 | #define MAX30102_REG_SPO2_CONFIG 0x0a | |
69 | #define MAX30102_REG_SPO2_CONFIG_PULSE_411_US 0x03 | |
70 | #define MAX30102_REG_SPO2_CONFIG_SR_400HZ 0x03 | |
71 | #define MAX30102_REG_SPO2_CONFIG_SR_MASK 0x07 | |
72 | #define MAX30102_REG_SPO2_CONFIG_SR_MASK_SHIFT 2 | |
73 | #define MAX30102_REG_SPO2_CONFIG_ADC_4096_STEPS BIT(0) | |
74 | #define MAX30102_REG_SPO2_CONFIG_ADC_MASK_SHIFT 5 | |
75 | ||
76 | #define MAX30102_REG_RED_LED_CONFIG 0x0c | |
77 | #define MAX30102_REG_IR_LED_CONFIG 0x0d | |
78 | ||
79 | #define MAX30102_REG_TEMP_CONFIG 0x21 | |
80 | #define MAX30102_REG_TEMP_CONFIG_TEMP_EN BIT(0) | |
81 | ||
82 | #define MAX30102_REG_TEMP_INTEGER 0x1f | |
83 | #define MAX30102_REG_TEMP_FRACTION 0x20 | |
84 | ||
85 | struct max30102_data { | |
86 | struct i2c_client *client; | |
87 | struct iio_dev *indio_dev; | |
88 | struct mutex lock; | |
89 | struct regmap *regmap; | |
90 | ||
91 | u8 buffer[8]; | |
92 | __be32 processed_buffer[2]; /* 2 x 18-bit (padded to 32-bits) */ | |
93 | }; | |
94 | ||
95 | static const struct regmap_config max30102_regmap_config = { | |
96 | .name = MAX30102_REGMAP_NAME, | |
97 | ||
98 | .reg_bits = 8, | |
99 | .val_bits = 8, | |
100 | }; | |
101 | ||
102 | static const unsigned long max30102_scan_masks[] = {0x3, 0}; | |
103 | ||
104 | static const struct iio_chan_spec max30102_channels[] = { | |
105 | { | |
106 | .type = IIO_INTENSITY, | |
107 | .channel2 = IIO_MOD_LIGHT_RED, | |
108 | .modified = 1, | |
109 | ||
110 | .scan_index = 0, | |
111 | .scan_type = { | |
112 | .sign = 'u', | |
113 | .shift = 8, | |
114 | .realbits = 18, | |
115 | .storagebits = 32, | |
116 | .endianness = IIO_BE, | |
117 | }, | |
118 | }, | |
119 | { | |
120 | .type = IIO_INTENSITY, | |
121 | .channel2 = IIO_MOD_LIGHT_IR, | |
122 | .modified = 1, | |
123 | ||
124 | .scan_index = 1, | |
125 | .scan_type = { | |
126 | .sign = 'u', | |
127 | .shift = 8, | |
128 | .realbits = 18, | |
129 | .storagebits = 32, | |
130 | .endianness = IIO_BE, | |
131 | }, | |
132 | }, | |
133 | { | |
134 | .type = IIO_TEMP, | |
135 | .info_mask_separate = | |
136 | BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), | |
137 | .scan_index = -1, | |
138 | }, | |
139 | }; | |
140 | ||
141 | static int max30102_set_powermode(struct max30102_data *data, bool state) | |
142 | { | |
143 | return regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG, | |
144 | MAX30102_REG_MODE_CONFIG_PWR, | |
145 | state ? 0 : MAX30102_REG_MODE_CONFIG_PWR); | |
146 | } | |
147 | ||
148 | static int max30102_buffer_postenable(struct iio_dev *indio_dev) | |
149 | { | |
150 | struct max30102_data *data = iio_priv(indio_dev); | |
151 | ||
152 | return max30102_set_powermode(data, true); | |
153 | } | |
154 | ||
155 | static int max30102_buffer_predisable(struct iio_dev *indio_dev) | |
156 | { | |
157 | struct max30102_data *data = iio_priv(indio_dev); | |
158 | ||
159 | return max30102_set_powermode(data, false); | |
160 | } | |
161 | ||
162 | static const struct iio_buffer_setup_ops max30102_buffer_setup_ops = { | |
163 | .postenable = max30102_buffer_postenable, | |
164 | .predisable = max30102_buffer_predisable, | |
165 | }; | |
166 | ||
167 | static inline int max30102_fifo_count(struct max30102_data *data) | |
168 | { | |
169 | unsigned int val; | |
170 | int ret; | |
171 | ||
172 | ret = regmap_read(data->regmap, MAX30102_REG_INT_STATUS, &val); | |
173 | if (ret) | |
174 | return ret; | |
175 | ||
176 | /* FIFO has one sample slot left */ | |
177 | if (val & MAX30102_REG_INT_STATUS_FIFO_RDY) | |
178 | return 1; | |
179 | ||
180 | return 0; | |
181 | } | |
182 | ||
183 | static int max30102_read_measurement(struct max30102_data *data) | |
184 | { | |
185 | int ret; | |
186 | u8 *buffer = (u8 *) &data->buffer; | |
187 | ||
188 | ret = i2c_smbus_read_i2c_block_data(data->client, | |
189 | MAX30102_REG_FIFO_DATA, | |
190 | MAX30102_REG_FIFO_DATA_ENTRY_LEN, | |
191 | buffer); | |
192 | ||
193 | memcpy(&data->processed_buffer[0], &buffer[0], 3); | |
194 | memcpy(&data->processed_buffer[1], &buffer[3], 3); | |
195 | ||
196 | return (ret == MAX30102_REG_FIFO_DATA_ENTRY_LEN) ? 0 : -EINVAL; | |
197 | } | |
198 | ||
199 | static irqreturn_t max30102_interrupt_handler(int irq, void *private) | |
200 | { | |
201 | struct iio_dev *indio_dev = private; | |
202 | struct max30102_data *data = iio_priv(indio_dev); | |
203 | int ret, cnt = 0; | |
204 | ||
205 | mutex_lock(&data->lock); | |
206 | ||
207 | while (cnt || (cnt = max30102_fifo_count(data)) > 0) { | |
208 | ret = max30102_read_measurement(data); | |
209 | if (ret) | |
210 | break; | |
211 | ||
212 | iio_push_to_buffers(data->indio_dev, data->processed_buffer); | |
213 | cnt--; | |
214 | } | |
215 | ||
216 | mutex_unlock(&data->lock); | |
217 | ||
218 | return IRQ_HANDLED; | |
219 | } | |
220 | ||
221 | static int max30102_get_current_idx(unsigned int val, int *reg) | |
222 | { | |
223 | /* each step is 0.200 mA */ | |
224 | *reg = val / 200; | |
225 | ||
226 | return *reg > 0xff ? -EINVAL : 0; | |
227 | } | |
228 | ||
229 | static int max30102_led_init(struct max30102_data *data) | |
230 | { | |
231 | struct device *dev = &data->client->dev; | |
232 | struct device_node *np = dev->of_node; | |
233 | unsigned int val; | |
234 | int reg, ret; | |
235 | ||
236 | ret = of_property_read_u32(np, "maxim,red-led-current-microamp", &val); | |
237 | if (ret) { | |
238 | dev_info(dev, "no red-led-current-microamp set\n"); | |
239 | ||
240 | /* Default to 7 mA RED LED */ | |
241 | val = 7000; | |
242 | } | |
243 | ||
244 | ret = max30102_get_current_idx(val, ®); | |
245 | if (ret) { | |
246 | dev_err(dev, "invalid RED LED current setting %d\n", val); | |
247 | return ret; | |
248 | } | |
249 | ||
250 | ret = regmap_write(data->regmap, MAX30102_REG_RED_LED_CONFIG, reg); | |
251 | if (ret) | |
252 | return ret; | |
253 | ||
254 | ret = of_property_read_u32(np, "maxim,ir-led-current-microamp", &val); | |
255 | if (ret) { | |
256 | dev_info(dev, "no ir-led-current-microamp set\n"); | |
257 | ||
258 | /* Default to 7 mA IR LED */ | |
259 | val = 7000; | |
260 | } | |
261 | ||
262 | ret = max30102_get_current_idx(val, ®); | |
263 | if (ret) { | |
264 | dev_err(dev, "invalid IR LED current setting %d", val); | |
265 | return ret; | |
266 | } | |
267 | ||
268 | return regmap_write(data->regmap, MAX30102_REG_IR_LED_CONFIG, reg); | |
269 | } | |
270 | ||
271 | static int max30102_chip_init(struct max30102_data *data) | |
272 | { | |
273 | int ret; | |
274 | ||
275 | /* setup LED current settings */ | |
276 | ret = max30102_led_init(data); | |
277 | if (ret) | |
278 | return ret; | |
279 | ||
280 | /* enable 18-bit HR + SPO2 readings at 400Hz */ | |
281 | ret = regmap_write(data->regmap, MAX30102_REG_SPO2_CONFIG, | |
282 | (MAX30102_REG_SPO2_CONFIG_ADC_4096_STEPS | |
283 | << MAX30102_REG_SPO2_CONFIG_ADC_MASK_SHIFT) | | |
284 | (MAX30102_REG_SPO2_CONFIG_SR_400HZ | |
285 | << MAX30102_REG_SPO2_CONFIG_SR_MASK_SHIFT) | | |
286 | MAX30102_REG_SPO2_CONFIG_PULSE_411_US); | |
287 | if (ret) | |
288 | return ret; | |
289 | ||
290 | /* enable SPO2 mode */ | |
291 | ret = regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG, | |
292 | MAX30102_REG_MODE_CONFIG_MODE_MASK, | |
293 | MAX30102_REG_MODE_CONFIG_MODE_HR_EN | | |
294 | MAX30102_REG_MODE_CONFIG_MODE_SPO2_EN); | |
295 | if (ret) | |
296 | return ret; | |
297 | ||
298 | /* average 4 samples + generate FIFO interrupt */ | |
299 | ret = regmap_write(data->regmap, MAX30102_REG_FIFO_CONFIG, | |
300 | (MAX30102_REG_FIFO_CONFIG_AVG_4SAMPLES | |
301 | << MAX30102_REG_FIFO_CONFIG_AVG_SHIFT) | | |
302 | MAX30102_REG_FIFO_CONFIG_AFULL); | |
303 | if (ret) | |
304 | return ret; | |
305 | ||
306 | /* enable FIFO interrupt */ | |
307 | return regmap_update_bits(data->regmap, MAX30102_REG_INT_ENABLE, | |
308 | MAX30102_REG_INT_ENABLE_MASK, | |
309 | MAX30102_REG_INT_ENABLE_FIFO_EN); | |
310 | } | |
311 | ||
312 | static int max30102_read_temp(struct max30102_data *data, int *val) | |
313 | { | |
314 | int ret; | |
315 | unsigned int reg; | |
316 | ||
317 | ret = regmap_read(data->regmap, MAX30102_REG_TEMP_INTEGER, ®); | |
318 | if (ret < 0) | |
319 | return ret; | |
320 | *val = reg << 4; | |
321 | ||
322 | ret = regmap_read(data->regmap, MAX30102_REG_TEMP_FRACTION, ®); | |
323 | if (ret < 0) | |
324 | return ret; | |
325 | ||
326 | *val |= reg & 0xf; | |
327 | *val = sign_extend32(*val, 11); | |
328 | ||
329 | return 0; | |
330 | } | |
331 | ||
332 | static int max30102_get_temp(struct max30102_data *data, int *val) | |
333 | { | |
334 | int ret; | |
335 | ||
336 | /* start acquisition */ | |
337 | ret = regmap_update_bits(data->regmap, MAX30102_REG_TEMP_CONFIG, | |
338 | MAX30102_REG_TEMP_CONFIG_TEMP_EN, | |
339 | MAX30102_REG_TEMP_CONFIG_TEMP_EN); | |
340 | if (ret) | |
341 | return ret; | |
342 | ||
343 | msleep(35); | |
344 | ||
345 | return max30102_read_temp(data, val); | |
346 | } | |
347 | ||
348 | static int max30102_read_raw(struct iio_dev *indio_dev, | |
349 | struct iio_chan_spec const *chan, | |
350 | int *val, int *val2, long mask) | |
351 | { | |
352 | struct max30102_data *data = iio_priv(indio_dev); | |
353 | int ret = -EINVAL; | |
354 | ||
355 | switch (mask) { | |
356 | case IIO_CHAN_INFO_RAW: | |
357 | /* | |
358 | * Temperature reading can only be acquired while engine | |
359 | * is running | |
360 | */ | |
361 | mutex_lock(&indio_dev->mlock); | |
362 | ||
363 | if (!iio_buffer_enabled(indio_dev)) | |
364 | ret = -EBUSY; | |
365 | else { | |
366 | ret = max30102_get_temp(data, val); | |
367 | if (!ret) | |
368 | ret = IIO_VAL_INT; | |
369 | } | |
370 | ||
371 | mutex_unlock(&indio_dev->mlock); | |
372 | break; | |
373 | case IIO_CHAN_INFO_SCALE: | |
374 | *val = 1; /* 0.0625 */ | |
375 | *val2 = 16; | |
376 | ret = IIO_VAL_FRACTIONAL; | |
377 | break; | |
378 | } | |
379 | ||
380 | return ret; | |
381 | } | |
382 | ||
383 | static const struct iio_info max30102_info = { | |
384 | .driver_module = THIS_MODULE, | |
385 | .read_raw = max30102_read_raw, | |
386 | }; | |
387 | ||
388 | static int max30102_probe(struct i2c_client *client, | |
389 | const struct i2c_device_id *id) | |
390 | { | |
391 | struct max30102_data *data; | |
392 | struct iio_buffer *buffer; | |
393 | struct iio_dev *indio_dev; | |
394 | int ret; | |
395 | ||
396 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); | |
397 | if (!indio_dev) | |
398 | return -ENOMEM; | |
399 | ||
400 | buffer = devm_iio_kfifo_allocate(&client->dev); | |
401 | if (!buffer) | |
402 | return -ENOMEM; | |
403 | ||
404 | iio_device_attach_buffer(indio_dev, buffer); | |
405 | ||
406 | indio_dev->name = MAX30102_DRV_NAME; | |
407 | indio_dev->channels = max30102_channels; | |
408 | indio_dev->info = &max30102_info; | |
409 | indio_dev->num_channels = ARRAY_SIZE(max30102_channels); | |
410 | indio_dev->available_scan_masks = max30102_scan_masks; | |
411 | indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE); | |
412 | indio_dev->setup_ops = &max30102_buffer_setup_ops; | |
fa722499 | 413 | indio_dev->dev.parent = &client->dev; |
b3c590ce MR |
414 | |
415 | data = iio_priv(indio_dev); | |
416 | data->indio_dev = indio_dev; | |
417 | data->client = client; | |
418 | ||
419 | mutex_init(&data->lock); | |
420 | i2c_set_clientdata(client, indio_dev); | |
421 | ||
422 | data->regmap = devm_regmap_init_i2c(client, &max30102_regmap_config); | |
423 | if (IS_ERR(data->regmap)) { | |
424 | dev_err(&client->dev, "regmap initialization failed.\n"); | |
425 | return PTR_ERR(data->regmap); | |
426 | } | |
427 | max30102_set_powermode(data, false); | |
428 | ||
429 | ret = max30102_chip_init(data); | |
430 | if (ret) | |
431 | return ret; | |
432 | ||
433 | if (client->irq <= 0) { | |
434 | dev_err(&client->dev, "no valid irq defined\n"); | |
435 | return -EINVAL; | |
436 | } | |
437 | ||
438 | ret = devm_request_threaded_irq(&client->dev, client->irq, | |
439 | NULL, max30102_interrupt_handler, | |
440 | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, | |
441 | "max30102_irq", indio_dev); | |
442 | if (ret) { | |
443 | dev_err(&client->dev, "request irq (%d) failed\n", client->irq); | |
444 | return ret; | |
445 | } | |
446 | ||
447 | return iio_device_register(indio_dev); | |
448 | } | |
449 | ||
450 | static int max30102_remove(struct i2c_client *client) | |
451 | { | |
452 | struct iio_dev *indio_dev = i2c_get_clientdata(client); | |
453 | struct max30102_data *data = iio_priv(indio_dev); | |
454 | ||
455 | iio_device_unregister(indio_dev); | |
456 | max30102_set_powermode(data, false); | |
457 | ||
458 | return 0; | |
459 | } | |
460 | ||
461 | static const struct i2c_device_id max30102_id[] = { | |
462 | { "max30102", 0 }, | |
463 | {} | |
464 | }; | |
465 | MODULE_DEVICE_TABLE(i2c, max30102_id); | |
466 | ||
467 | static const struct of_device_id max30102_dt_ids[] = { | |
468 | { .compatible = "maxim,max30102" }, | |
469 | { } | |
470 | }; | |
471 | MODULE_DEVICE_TABLE(of, max30102_dt_ids); | |
472 | ||
473 | static struct i2c_driver max30102_driver = { | |
474 | .driver = { | |
475 | .name = MAX30102_DRV_NAME, | |
476 | .of_match_table = of_match_ptr(max30102_dt_ids), | |
477 | }, | |
478 | .probe = max30102_probe, | |
479 | .remove = max30102_remove, | |
480 | .id_table = max30102_id, | |
481 | }; | |
482 | module_i2c_driver(max30102_driver); | |
483 | ||
484 | MODULE_AUTHOR("Matt Ranostay <matt@ranostay.consulting>"); | |
485 | MODULE_DESCRIPTION("MAX30102 heart rate and pulse oximeter sensor"); | |
486 | MODULE_LICENSE("GPL"); |