2 * MAX44000 Ambient and Infrared Proximity Sensor
4 * Copyright (c) 2016, Intel Corporation.
6 * This file is subject to the terms and conditions of version 2 of
7 * the GNU General Public License. See the file COPYING in the main
8 * directory of this archive for more details.
10 * Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf
12 * 7-bit I2C slave address 0x4a
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/i2c.h>
18 #include <linux/regmap.h>
19 #include <linux/util_macros.h>
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/trigger_consumer.h>
24 #include <linux/iio/triggered_buffer.h>
25 #include <linux/acpi.h>
27 #define MAX44000_DRV_NAME "max44000"
29 /* Registers in datasheet order */
30 #define MAX44000_REG_STATUS 0x00
31 #define MAX44000_REG_CFG_MAIN 0x01
32 #define MAX44000_REG_CFG_RX 0x02
33 #define MAX44000_REG_CFG_TX 0x03
34 #define MAX44000_REG_ALS_DATA_HI 0x04
35 #define MAX44000_REG_ALS_DATA_LO 0x05
36 #define MAX44000_REG_PRX_DATA 0x16
37 #define MAX44000_REG_ALS_UPTHR_HI 0x06
38 #define MAX44000_REG_ALS_UPTHR_LO 0x07
39 #define MAX44000_REG_ALS_LOTHR_HI 0x08
40 #define MAX44000_REG_ALS_LOTHR_LO 0x09
41 #define MAX44000_REG_PST 0x0a
42 #define MAX44000_REG_PRX_IND 0x0b
43 #define MAX44000_REG_PRX_THR 0x0c
44 #define MAX44000_REG_TRIM_GAIN_GREEN 0x0f
45 #define MAX44000_REG_TRIM_GAIN_IR 0x10
48 #define MAX44000_CFG_ALSINTE 0x01
49 #define MAX44000_CFG_PRXINTE 0x02
50 #define MAX44000_CFG_MASK 0x1c
51 #define MAX44000_CFG_MODE_SHUTDOWN 0x00
52 #define MAX44000_CFG_MODE_ALS_GIR 0x04
53 #define MAX44000_CFG_MODE_ALS_G 0x08
54 #define MAX44000_CFG_MODE_ALS_IR 0x0c
55 #define MAX44000_CFG_MODE_ALS_PRX 0x10
56 #define MAX44000_CFG_MODE_PRX 0x14
57 #define MAX44000_CFG_TRIM 0x20
60 * Upper 4 bits are not documented but start as 1 on powerup
61 * Setting them to 0 causes proximity to misbehave so set them to 1
63 #define MAX44000_REG_CFG_RX_DEFAULT 0xf0
66 #define MAX44000_CFG_RX_ALSTIM_MASK 0x0c
67 #define MAX44000_CFG_RX_ALSTIM_SHIFT 2
68 #define MAX44000_CFG_RX_ALSPGA_MASK 0x03
69 #define MAX44000_CFG_RX_ALSPGA_SHIFT 0
72 #define MAX44000_LED_CURRENT_MASK 0xf
73 #define MAX44000_LED_CURRENT_MAX 11
74 #define MAX44000_LED_CURRENT_DEFAULT 6
76 #define MAX44000_ALSDATA_OVERFLOW 0x4000
78 struct max44000_data {
80 struct regmap *regmap;
81 /* Ensure naturally aligned timestamp */
88 /* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */
89 #define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5
91 /* Scale can be multiplied by up to 128x via ALSPGA for measurement gain */
92 static const int max44000_alspga_shift[] = {0, 2, 4, 7};
93 #define MAX44000_ALSPGA_MAX_SHIFT 7
96 * Scale can be multiplied by up to 64x via ALSTIM because of lost resolution
98 * This scaling factor is hidden from userspace and instead accounted for when
99 * reading raw values from the device.
101 * This makes it possible to cleanly expose ALSPGA as IIO_CHAN_INFO_SCALE and
102 * ALSTIM as IIO_CHAN_INFO_INT_TIME without the values affecting each other.
104 * Handling this internally is also required for buffer support because the
105 * channel's scan_type can't be modified dynamically.
107 static const int max44000_alstim_shift[] = {0, 2, 4, 6};
108 #define MAX44000_ALSTIM_SHIFT(alstim) (2 * (alstim))
110 /* Available integration times with pretty manual alignment: */
111 static const int max44000_int_time_avail_ns_array[] = {
117 static const char max44000_int_time_avail_str[] =
123 /* Available scales (internal to ulux) with pretty manual alignment: */
124 static const int max44000_scale_avail_ulux_array[] = {
130 static const char max44000_scale_avail_str[] =
136 #define MAX44000_SCAN_INDEX_ALS 0
137 #define MAX44000_SCAN_INDEX_PRX 1
139 static const struct iio_chan_spec max44000_channels[] = {
142 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
143 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
144 BIT(IIO_CHAN_INFO_INT_TIME),
145 .scan_index = MAX44000_SCAN_INDEX_ALS,
153 .type = IIO_PROXIMITY,
154 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
155 .scan_index = MAX44000_SCAN_INDEX_PRX,
162 IIO_CHAN_SOFT_TIMESTAMP(2),
165 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
166 BIT(IIO_CHAN_INFO_SCALE),
167 .extend_name = "led",
173 static int max44000_read_alstim(struct max44000_data *data)
178 ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);
181 return (val & MAX44000_CFG_RX_ALSTIM_MASK) >> MAX44000_CFG_RX_ALSTIM_SHIFT;
184 static int max44000_write_alstim(struct max44000_data *data, int val)
186 return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,
187 MAX44000_CFG_RX_ALSTIM_MASK,
188 val << MAX44000_CFG_RX_ALSTIM_SHIFT);
191 static int max44000_read_alspga(struct max44000_data *data)
196 ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);
199 return (val & MAX44000_CFG_RX_ALSPGA_MASK) >> MAX44000_CFG_RX_ALSPGA_SHIFT;
202 static int max44000_write_alspga(struct max44000_data *data, int val)
204 return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,
205 MAX44000_CFG_RX_ALSPGA_MASK,
206 val << MAX44000_CFG_RX_ALSPGA_SHIFT);
209 static int max44000_read_alsval(struct max44000_data *data)
215 ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI,
219 alstim = ret = max44000_read_alstim(data);
223 regval = be16_to_cpu(val);
226 * Overflow is explained on datasheet page 17.
228 * It's a warning that either the G or IR channel has become saturated
229 * and that the value in the register is likely incorrect.
231 * The recommendation is to change the scale (ALSPGA).
232 * The driver just returns the max representable value.
234 if (regval & MAX44000_ALSDATA_OVERFLOW)
237 return regval << MAX44000_ALSTIM_SHIFT(alstim);
240 static int max44000_write_led_current_raw(struct max44000_data *data, int val)
242 /* Maybe we should clamp the value instead? */
243 if (val < 0 || val > MAX44000_LED_CURRENT_MAX)
247 return regmap_write_bits(data->regmap, MAX44000_REG_CFG_TX,
248 MAX44000_LED_CURRENT_MASK, val);
251 static int max44000_read_led_current_raw(struct max44000_data *data)
256 ret = regmap_read(data->regmap, MAX44000_REG_CFG_TX, ®val);
259 regval &= MAX44000_LED_CURRENT_MASK;
265 static int max44000_read_raw(struct iio_dev *indio_dev,
266 struct iio_chan_spec const *chan,
267 int *val, int *val2, long mask)
269 struct max44000_data *data = iio_priv(indio_dev);
275 case IIO_CHAN_INFO_RAW:
276 switch (chan->type) {
278 mutex_lock(&data->lock);
279 ret = max44000_read_alsval(data);
280 mutex_unlock(&data->lock);
287 mutex_lock(&data->lock);
288 ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, ®val);
289 mutex_unlock(&data->lock);
296 mutex_lock(&data->lock);
297 ret = max44000_read_led_current_raw(data);
298 mutex_unlock(&data->lock);
308 case IIO_CHAN_INFO_SCALE:
309 switch (chan->type) {
311 /* Output register is in 10s of miliamps */
316 mutex_lock(&data->lock);
317 alspga = ret = max44000_read_alspga(data);
318 mutex_unlock(&data->lock);
322 /* Avoid negative shifts */
323 *val = (1 << MAX44000_ALSPGA_MAX_SHIFT);
324 *val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2
325 + MAX44000_ALSPGA_MAX_SHIFT
326 - max44000_alspga_shift[alspga];
327 return IIO_VAL_FRACTIONAL_LOG2;
333 case IIO_CHAN_INFO_INT_TIME:
334 mutex_lock(&data->lock);
335 alstim = ret = max44000_read_alstim(data);
336 mutex_unlock(&data->lock);
341 *val2 = max44000_int_time_avail_ns_array[alstim];
342 return IIO_VAL_INT_PLUS_NANO;
349 static int max44000_write_raw(struct iio_dev *indio_dev,
350 struct iio_chan_spec const *chan,
351 int val, int val2, long mask)
353 struct max44000_data *data = iio_priv(indio_dev);
356 if (mask == IIO_CHAN_INFO_RAW && chan->type == IIO_CURRENT) {
357 mutex_lock(&data->lock);
358 ret = max44000_write_led_current_raw(data, val);
359 mutex_unlock(&data->lock);
361 } else if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT) {
362 s64 valns = val * NSEC_PER_SEC + val2;
363 int alstim = find_closest_descending(valns,
364 max44000_int_time_avail_ns_array,
365 ARRAY_SIZE(max44000_int_time_avail_ns_array));
366 mutex_lock(&data->lock);
367 ret = max44000_write_alstim(data, alstim);
368 mutex_unlock(&data->lock);
370 } else if (mask == IIO_CHAN_INFO_SCALE && chan->type == IIO_LIGHT) {
371 s64 valus = val * USEC_PER_SEC + val2;
372 int alspga = find_closest(valus,
373 max44000_scale_avail_ulux_array,
374 ARRAY_SIZE(max44000_scale_avail_ulux_array));
375 mutex_lock(&data->lock);
376 ret = max44000_write_alspga(data, alspga);
377 mutex_unlock(&data->lock);
384 static int max44000_write_raw_get_fmt(struct iio_dev *indio_dev,
385 struct iio_chan_spec const *chan,
388 if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT)
389 return IIO_VAL_INT_PLUS_NANO;
390 else if (mask == IIO_CHAN_INFO_SCALE && chan->type == IIO_LIGHT)
391 return IIO_VAL_INT_PLUS_MICRO;
396 static IIO_CONST_ATTR(illuminance_integration_time_available, max44000_int_time_avail_str);
397 static IIO_CONST_ATTR(illuminance_scale_available, max44000_scale_avail_str);
399 static struct attribute *max44000_attributes[] = {
400 &iio_const_attr_illuminance_integration_time_available.dev_attr.attr,
401 &iio_const_attr_illuminance_scale_available.dev_attr.attr,
405 static const struct attribute_group max44000_attribute_group = {
406 .attrs = max44000_attributes,
409 static const struct iio_info max44000_info = {
410 .driver_module = THIS_MODULE,
411 .read_raw = max44000_read_raw,
412 .write_raw = max44000_write_raw,
413 .write_raw_get_fmt = max44000_write_raw_get_fmt,
414 .attrs = &max44000_attribute_group,
417 static bool max44000_readable_reg(struct device *dev, unsigned int reg)
420 case MAX44000_REG_STATUS:
421 case MAX44000_REG_CFG_MAIN:
422 case MAX44000_REG_CFG_RX:
423 case MAX44000_REG_CFG_TX:
424 case MAX44000_REG_ALS_DATA_HI:
425 case MAX44000_REG_ALS_DATA_LO:
426 case MAX44000_REG_PRX_DATA:
427 case MAX44000_REG_ALS_UPTHR_HI:
428 case MAX44000_REG_ALS_UPTHR_LO:
429 case MAX44000_REG_ALS_LOTHR_HI:
430 case MAX44000_REG_ALS_LOTHR_LO:
431 case MAX44000_REG_PST:
432 case MAX44000_REG_PRX_IND:
433 case MAX44000_REG_PRX_THR:
434 case MAX44000_REG_TRIM_GAIN_GREEN:
435 case MAX44000_REG_TRIM_GAIN_IR:
442 static bool max44000_writeable_reg(struct device *dev, unsigned int reg)
445 case MAX44000_REG_CFG_MAIN:
446 case MAX44000_REG_CFG_RX:
447 case MAX44000_REG_CFG_TX:
448 case MAX44000_REG_ALS_UPTHR_HI:
449 case MAX44000_REG_ALS_UPTHR_LO:
450 case MAX44000_REG_ALS_LOTHR_HI:
451 case MAX44000_REG_ALS_LOTHR_LO:
452 case MAX44000_REG_PST:
453 case MAX44000_REG_PRX_IND:
454 case MAX44000_REG_PRX_THR:
455 case MAX44000_REG_TRIM_GAIN_GREEN:
456 case MAX44000_REG_TRIM_GAIN_IR:
463 static bool max44000_volatile_reg(struct device *dev, unsigned int reg)
466 case MAX44000_REG_STATUS:
467 case MAX44000_REG_ALS_DATA_HI:
468 case MAX44000_REG_ALS_DATA_LO:
469 case MAX44000_REG_PRX_DATA:
476 static bool max44000_precious_reg(struct device *dev, unsigned int reg)
478 return reg == MAX44000_REG_STATUS;
481 static const struct regmap_config max44000_regmap_config = {
485 .max_register = MAX44000_REG_PRX_DATA,
486 .readable_reg = max44000_readable_reg,
487 .writeable_reg = max44000_writeable_reg,
488 .volatile_reg = max44000_volatile_reg,
489 .precious_reg = max44000_precious_reg,
492 .cache_type = REGCACHE_RBTREE,
495 static irqreturn_t max44000_trigger_handler(int irq, void *p)
497 struct iio_poll_func *pf = p;
498 struct iio_dev *indio_dev = pf->indio_dev;
499 struct max44000_data *data = iio_priv(indio_dev);
504 mutex_lock(&data->lock);
505 if (test_bit(MAX44000_SCAN_INDEX_ALS, indio_dev->active_scan_mask)) {
506 ret = max44000_read_alsval(data);
509 data->scan.channels[index++] = ret;
511 if (test_bit(MAX44000_SCAN_INDEX_PRX, indio_dev->active_scan_mask)) {
512 ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, ®val);
515 data->scan.channels[index] = regval;
517 mutex_unlock(&data->lock);
519 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
520 iio_get_time_ns(indio_dev));
521 iio_trigger_notify_done(indio_dev->trig);
525 mutex_unlock(&data->lock);
526 iio_trigger_notify_done(indio_dev->trig);
530 static int max44000_probe(struct i2c_client *client,
531 const struct i2c_device_id *id)
533 struct max44000_data *data;
534 struct iio_dev *indio_dev;
537 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
540 data = iio_priv(indio_dev);
541 data->regmap = devm_regmap_init_i2c(client, &max44000_regmap_config);
542 if (IS_ERR(data->regmap)) {
543 dev_err(&client->dev, "regmap_init failed!\n");
544 return PTR_ERR(data->regmap);
547 i2c_set_clientdata(client, indio_dev);
548 mutex_init(&data->lock);
549 indio_dev->dev.parent = &client->dev;
550 indio_dev->info = &max44000_info;
551 indio_dev->name = MAX44000_DRV_NAME;
552 indio_dev->channels = max44000_channels;
553 indio_dev->num_channels = ARRAY_SIZE(max44000_channels);
556 * The device doesn't have a reset function so we just clear some
557 * important bits at probe time to ensure sane operation.
559 * Since we don't support interrupts/events the threshold values are
560 * not important. We also don't touch trim values.
563 /* Reset ALS scaling bits */
564 ret = regmap_write(data->regmap, MAX44000_REG_CFG_RX,
565 MAX44000_REG_CFG_RX_DEFAULT);
567 dev_err(&client->dev, "failed to write default CFG_RX: %d\n",
573 * By default the LED pulse used for the proximity sensor is disabled.
574 * Set a middle value so that we get some sort of valid data by default.
576 ret = max44000_write_led_current_raw(data, MAX44000_LED_CURRENT_DEFAULT);
578 dev_err(&client->dev, "failed to write init config: %d\n", ret);
582 /* Reset CFG bits to ALS_PRX mode which allows easy reading of both values. */
583 reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_PRX;
584 ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
586 dev_err(&client->dev, "failed to write init config: %d\n", ret);
590 /* Read status at least once to clear any stale interrupt bits. */
591 ret = regmap_read(data->regmap, MAX44000_REG_STATUS, ®);
593 dev_err(&client->dev, "failed to read init status: %d\n", ret);
597 ret = iio_triggered_buffer_setup(indio_dev, NULL, max44000_trigger_handler, NULL);
599 dev_err(&client->dev, "iio triggered buffer setup failed\n");
603 return iio_device_register(indio_dev);
606 static int max44000_remove(struct i2c_client *client)
608 struct iio_dev *indio_dev = i2c_get_clientdata(client);
610 iio_device_unregister(indio_dev);
611 iio_triggered_buffer_cleanup(indio_dev);
616 static const struct i2c_device_id max44000_id[] = {
620 MODULE_DEVICE_TABLE(i2c, max44000_id);
623 static const struct acpi_device_id max44000_acpi_match[] = {
627 MODULE_DEVICE_TABLE(acpi, max44000_acpi_match);
630 static struct i2c_driver max44000_driver = {
632 .name = MAX44000_DRV_NAME,
633 .acpi_match_table = ACPI_PTR(max44000_acpi_match),
635 .probe = max44000_probe,
636 .remove = max44000_remove,
637 .id_table = max44000_id,
640 module_i2c_driver(max44000_driver);
642 MODULE_AUTHOR("Crestez Dan Leonard <leonard.crestez@intel.com>");
643 MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor");
644 MODULE_LICENSE("GPL v2");