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11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/interrupt.h>
14#include <linux/delay.h>
15#include <linux/err.h>
16#include <linux/irq.h>
17#include <linux/i2c.h>
18#include <linux/mutex.h>
19#include <linux/property.h>
20#include <linux/regmap.h>
21#include <linux/iio/iio.h>
22#include <linux/iio/buffer.h>
23#include <linux/iio/kfifo_buf.h>
24
25#define MAX30100_REGMAP_NAME "max30100_regmap"
26#define MAX30100_DRV_NAME "max30100"
27
28#define MAX30100_REG_INT_STATUS 0x00
29#define MAX30100_REG_INT_STATUS_PWR_RDY BIT(0)
30#define MAX30100_REG_INT_STATUS_SPO2_RDY BIT(4)
31#define MAX30100_REG_INT_STATUS_HR_RDY BIT(5)
32#define MAX30100_REG_INT_STATUS_FIFO_RDY BIT(7)
33
34#define MAX30100_REG_INT_ENABLE 0x01
35#define MAX30100_REG_INT_ENABLE_SPO2_EN BIT(0)
36#define MAX30100_REG_INT_ENABLE_HR_EN BIT(1)
37#define MAX30100_REG_INT_ENABLE_FIFO_EN BIT(3)
38#define MAX30100_REG_INT_ENABLE_MASK 0xf0
39#define MAX30100_REG_INT_ENABLE_MASK_SHIFT 4
40
41#define MAX30100_REG_FIFO_WR_PTR 0x02
42#define MAX30100_REG_FIFO_OVR_CTR 0x03
43#define MAX30100_REG_FIFO_RD_PTR 0x04
44#define MAX30100_REG_FIFO_DATA 0x05
45#define MAX30100_REG_FIFO_DATA_ENTRY_COUNT 16
46#define MAX30100_REG_FIFO_DATA_ENTRY_LEN 4
47
48#define MAX30100_REG_MODE_CONFIG 0x06
49#define MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN BIT(0)
50#define MAX30100_REG_MODE_CONFIG_MODE_HR_EN BIT(1)
51#define MAX30100_REG_MODE_CONFIG_MODE_MASK 0x03
52#define MAX30100_REG_MODE_CONFIG_TEMP_EN BIT(3)
53#define MAX30100_REG_MODE_CONFIG_PWR BIT(7)
54
55#define MAX30100_REG_SPO2_CONFIG 0x07
56#define MAX30100_REG_SPO2_CONFIG_100HZ BIT(2)
57#define MAX30100_REG_SPO2_CONFIG_HI_RES_EN BIT(6)
58#define MAX30100_REG_SPO2_CONFIG_1600US 0x3
59
60#define MAX30100_REG_LED_CONFIG 0x09
61#define MAX30100_REG_LED_CONFIG_LED_MASK 0x0f
62#define MAX30100_REG_LED_CONFIG_RED_LED_SHIFT 4
63
64#define MAX30100_REG_LED_CONFIG_24MA 0x07
65#define MAX30100_REG_LED_CONFIG_50MA 0x0f
66
67#define MAX30100_REG_TEMP_INTEGER 0x16
68#define MAX30100_REG_TEMP_FRACTION 0x17
69
70struct max30100_data {
71 struct i2c_client *client;
72 struct iio_dev *indio_dev;
73 struct mutex lock;
74 struct regmap *regmap;
75
76 __be16 buffer[2];
77};
78
79static bool max30100_is_volatile_reg(struct device *dev, unsigned int reg)
80{
81 switch (reg) {
82 case MAX30100_REG_INT_STATUS:
83 case MAX30100_REG_MODE_CONFIG:
84 case MAX30100_REG_FIFO_WR_PTR:
85 case MAX30100_REG_FIFO_OVR_CTR:
86 case MAX30100_REG_FIFO_RD_PTR:
87 case MAX30100_REG_FIFO_DATA:
88 case MAX30100_REG_TEMP_INTEGER:
89 case MAX30100_REG_TEMP_FRACTION:
90 return true;
91 default:
92 return false;
93 }
94}
95
96static const struct regmap_config max30100_regmap_config = {
97 .name = MAX30100_REGMAP_NAME,
98
99 .reg_bits = 8,
100 .val_bits = 8,
101
102 .max_register = MAX30100_REG_TEMP_FRACTION,
103 .cache_type = REGCACHE_FLAT,
104
105 .volatile_reg = max30100_is_volatile_reg,
106};
107
108static const unsigned int max30100_led_current_mapping[] = {
109 4400, 7600, 11000, 14200, 17400,
110 20800, 24000, 27100, 30600, 33800,
111 37000, 40200, 43600, 46800, 50000
112};
113
114static const unsigned long max30100_scan_masks[] = {0x3, 0};
115
116static const struct iio_chan_spec max30100_channels[] = {
117 {
118 .type = IIO_INTENSITY,
119 .channel2 = IIO_MOD_LIGHT_IR,
120 .modified = 1,
121
122 .scan_index = 0,
123 .scan_type = {
124 .sign = 'u',
125 .realbits = 16,
126 .storagebits = 16,
127 .endianness = IIO_BE,
128 },
129 },
130 {
131 .type = IIO_INTENSITY,
132 .channel2 = IIO_MOD_LIGHT_RED,
133 .modified = 1,
134
135 .scan_index = 1,
136 .scan_type = {
137 .sign = 'u',
138 .realbits = 16,
139 .storagebits = 16,
140 .endianness = IIO_BE,
141 },
142 },
143 {
144 .type = IIO_TEMP,
145 .info_mask_separate =
146 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
147 .scan_index = -1,
148 },
149};
150
151static int max30100_set_powermode(struct max30100_data *data, bool state)
152{
153 return regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,
154 MAX30100_REG_MODE_CONFIG_PWR,
155 state ? 0 : MAX30100_REG_MODE_CONFIG_PWR);
156}
157
158static int max30100_clear_fifo(struct max30100_data *data)
159{
160 int ret;
161
162 ret = regmap_write(data->regmap, MAX30100_REG_FIFO_WR_PTR, 0);
163 if (ret)
164 return ret;
165
166 ret = regmap_write(data->regmap, MAX30100_REG_FIFO_OVR_CTR, 0);
167 if (ret)
168 return ret;
169
170 return regmap_write(data->regmap, MAX30100_REG_FIFO_RD_PTR, 0);
171}
172
173static int max30100_buffer_postenable(struct iio_dev *indio_dev)
174{
175 struct max30100_data *data = iio_priv(indio_dev);
176 int ret;
177
178 ret = max30100_set_powermode(data, true);
179 if (ret)
180 return ret;
181
182 return max30100_clear_fifo(data);
183}
184
185static int max30100_buffer_predisable(struct iio_dev *indio_dev)
186{
187 struct max30100_data *data = iio_priv(indio_dev);
188
189 return max30100_set_powermode(data, false);
190}
191
192static const struct iio_buffer_setup_ops max30100_buffer_setup_ops = {
193 .postenable = max30100_buffer_postenable,
194 .predisable = max30100_buffer_predisable,
195};
196
197static inline int max30100_fifo_count(struct max30100_data *data)
198{
199 unsigned int val;
200 int ret;
201
202 ret = regmap_read(data->regmap, MAX30100_REG_INT_STATUS, &val);
203 if (ret)
204 return ret;
205
206
207 if (val & MAX30100_REG_INT_STATUS_FIFO_RDY)
208 return MAX30100_REG_FIFO_DATA_ENTRY_COUNT - 1;
209
210 return 0;
211}
212
213static int max30100_read_measurement(struct max30100_data *data)
214{
215 int ret;
216
217 ret = i2c_smbus_read_i2c_block_data(data->client,
218 MAX30100_REG_FIFO_DATA,
219 MAX30100_REG_FIFO_DATA_ENTRY_LEN,
220 (u8 *) &data->buffer);
221
222 return (ret == MAX30100_REG_FIFO_DATA_ENTRY_LEN) ? 0 : ret;
223}
224
225static irqreturn_t max30100_interrupt_handler(int irq, void *private)
226{
227 struct iio_dev *indio_dev = private;
228 struct max30100_data *data = iio_priv(indio_dev);
229 int ret, cnt = 0;
230
231 mutex_lock(&data->lock);
232
233 while (cnt || (cnt = max30100_fifo_count(data)) > 0) {
234 ret = max30100_read_measurement(data);
235 if (ret)
236 break;
237
238 iio_push_to_buffers(data->indio_dev, data->buffer);
239 cnt--;
240 }
241
242 mutex_unlock(&data->lock);
243
244 return IRQ_HANDLED;
245}
246
247static int max30100_get_current_idx(unsigned int val, int *reg)
248{
249 int idx;
250
251
252 if (val == 0) {
253 *reg = 0;
254 return 0;
255 }
256
257 for (idx = 0; idx < ARRAY_SIZE(max30100_led_current_mapping); idx++) {
258 if (max30100_led_current_mapping[idx] == val) {
259 *reg = idx + 1;
260 return 0;
261 }
262 }
263
264 return -EINVAL;
265}
266
267static int max30100_led_init(struct max30100_data *data)
268{
269 struct device *dev = &data->client->dev;
270 unsigned int val[2];
271 int reg, ret;
272
273 ret = device_property_read_u32_array(dev, "maxim,led-current-microamp",
274 (unsigned int *) &val, 2);
275 if (ret) {
276
277 reg = (MAX30100_REG_LED_CONFIG_24MA <<
278 MAX30100_REG_LED_CONFIG_RED_LED_SHIFT) |
279 MAX30100_REG_LED_CONFIG_50MA;
280 dev_warn(dev, "no led-current-microamp set");
281
282 return regmap_write(data->regmap, MAX30100_REG_LED_CONFIG, reg);
283 }
284
285
286 ret = max30100_get_current_idx(val[0], ®);
287 if (ret) {
288 dev_err(dev, "invalid RED current setting %d", val[0]);
289 return ret;
290 }
291
292 ret = regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG,
293 MAX30100_REG_LED_CONFIG_LED_MASK <<
294 MAX30100_REG_LED_CONFIG_RED_LED_SHIFT,
295 reg << MAX30100_REG_LED_CONFIG_RED_LED_SHIFT);
296 if (ret)
297 return ret;
298
299
300 ret = max30100_get_current_idx(val[1], ®);
301 if (ret) {
302 dev_err(dev, "invalid IR current setting %d", val[1]);
303 return ret;
304 }
305
306 return regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG,
307 MAX30100_REG_LED_CONFIG_LED_MASK, reg);
308}
309
310static int max30100_chip_init(struct max30100_data *data)
311{
312 int ret;
313
314
315 ret = max30100_led_init(data);
316 if (ret)
317 return ret;
318
319
320 ret = regmap_write(data->regmap, MAX30100_REG_SPO2_CONFIG,
321 MAX30100_REG_SPO2_CONFIG_HI_RES_EN |
322 MAX30100_REG_SPO2_CONFIG_100HZ);
323 if (ret)
324 return ret;
325
326
327 ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,
328 MAX30100_REG_MODE_CONFIG_MODE_MASK,
329 MAX30100_REG_MODE_CONFIG_MODE_HR_EN |
330 MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN);
331 if (ret)
332 return ret;
333
334
335 return regmap_update_bits(data->regmap, MAX30100_REG_INT_ENABLE,
336 MAX30100_REG_INT_ENABLE_MASK,
337 MAX30100_REG_INT_ENABLE_FIFO_EN
338 << MAX30100_REG_INT_ENABLE_MASK_SHIFT);
339}
340
341static int max30100_read_temp(struct max30100_data *data, int *val)
342{
343 int ret;
344 unsigned int reg;
345
346 ret = regmap_read(data->regmap, MAX30100_REG_TEMP_INTEGER, ®);
347 if (ret < 0)
348 return ret;
349 *val = reg << 4;
350
351 ret = regmap_read(data->regmap, MAX30100_REG_TEMP_FRACTION, ®);
352 if (ret < 0)
353 return ret;
354
355 *val |= reg & 0xf;
356 *val = sign_extend32(*val, 11);
357
358 return 0;
359}
360
361static int max30100_get_temp(struct max30100_data *data, int *val)
362{
363 int ret;
364
365
366 ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,
367 MAX30100_REG_MODE_CONFIG_TEMP_EN,
368 MAX30100_REG_MODE_CONFIG_TEMP_EN);
369 if (ret)
370 return ret;
371
372 msleep(35);
373
374 return max30100_read_temp(data, val);
375}
376
377static int max30100_read_raw(struct iio_dev *indio_dev,
378 struct iio_chan_spec const *chan,
379 int *val, int *val2, long mask)
380{
381 struct max30100_data *data = iio_priv(indio_dev);
382 int ret = -EINVAL;
383
384 switch (mask) {
385 case IIO_CHAN_INFO_RAW:
386
387
388
389
390 mutex_lock(&indio_dev->mlock);
391
392 if (!iio_buffer_enabled(indio_dev))
393 ret = -EAGAIN;
394 else {
395 ret = max30100_get_temp(data, val);
396 if (!ret)
397 ret = IIO_VAL_INT;
398
399 }
400
401 mutex_unlock(&indio_dev->mlock);
402 break;
403 case IIO_CHAN_INFO_SCALE:
404 *val = 1;
405 *val2 = 16;
406 ret = IIO_VAL_FRACTIONAL;
407 break;
408 }
409
410 return ret;
411}
412
413static const struct iio_info max30100_info = {
414 .read_raw = max30100_read_raw,
415};
416
417static int max30100_probe(struct i2c_client *client,
418 const struct i2c_device_id *id)
419{
420 struct max30100_data *data;
421 struct iio_dev *indio_dev;
422 int ret;
423
424 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
425 if (!indio_dev)
426 return -ENOMEM;
427
428 indio_dev->name = MAX30100_DRV_NAME;
429 indio_dev->channels = max30100_channels;
430 indio_dev->info = &max30100_info;
431 indio_dev->num_channels = ARRAY_SIZE(max30100_channels);
432 indio_dev->available_scan_masks = max30100_scan_masks;
433 indio_dev->modes = INDIO_DIRECT_MODE;
434
435 ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev,
436 INDIO_BUFFER_SOFTWARE,
437 &max30100_buffer_setup_ops);
438 if (ret)
439 return ret;
440
441 data = iio_priv(indio_dev);
442 data->indio_dev = indio_dev;
443 data->client = client;
444
445 mutex_init(&data->lock);
446 i2c_set_clientdata(client, indio_dev);
447
448 data->regmap = devm_regmap_init_i2c(client, &max30100_regmap_config);
449 if (IS_ERR(data->regmap)) {
450 dev_err(&client->dev, "regmap initialization failed.\n");
451 return PTR_ERR(data->regmap);
452 }
453 max30100_set_powermode(data, false);
454
455 ret = max30100_chip_init(data);
456 if (ret)
457 return ret;
458
459 if (client->irq <= 0) {
460 dev_err(&client->dev, "no valid irq defined\n");
461 return -EINVAL;
462 }
463 ret = devm_request_threaded_irq(&client->dev, client->irq,
464 NULL, max30100_interrupt_handler,
465 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
466 "max30100_irq", indio_dev);
467 if (ret) {
468 dev_err(&client->dev, "request irq (%d) failed\n", client->irq);
469 return ret;
470 }
471
472 return iio_device_register(indio_dev);
473}
474
475static int max30100_remove(struct i2c_client *client)
476{
477 struct iio_dev *indio_dev = i2c_get_clientdata(client);
478 struct max30100_data *data = iio_priv(indio_dev);
479
480 iio_device_unregister(indio_dev);
481 max30100_set_powermode(data, false);
482
483 return 0;
484}
485
486static const struct i2c_device_id max30100_id[] = {
487 { "max30100", 0 },
488 {}
489};
490MODULE_DEVICE_TABLE(i2c, max30100_id);
491
492static const struct of_device_id max30100_dt_ids[] = {
493 { .compatible = "maxim,max30100" },
494 { }
495};
496MODULE_DEVICE_TABLE(of, max30100_dt_ids);
497
498static struct i2c_driver max30100_driver = {
499 .driver = {
500 .name = MAX30100_DRV_NAME,
501 .of_match_table = max30100_dt_ids,
502 },
503 .probe = max30100_probe,
504 .remove = max30100_remove,
505 .id_table = max30100_id,
506};
507module_i2c_driver(max30100_driver);
508
509MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
510MODULE_DESCRIPTION("MAX30100 heart rate and pulse oximeter sensor");
511MODULE_LICENSE("GPL");
512
