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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * MAX44000 Ambient and Infrared Proximity Sensor4 *5 * Copyright (c) 2016, Intel Corporation.6 *7 * Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf8 *9 * 7-bit I2C slave address 0x4a10 */11 12#include <linux/module.h>13#include <linux/mod_devicetable.h>14#include <linux/init.h>15#include <linux/i2c.h>16#include <linux/regmap.h>17#include <linux/util_macros.h>18#include <linux/iio/iio.h>19#include <linux/iio/sysfs.h>20#include <linux/iio/buffer.h>21#include <linux/iio/trigger_consumer.h>22#include <linux/iio/triggered_buffer.h>23 24#define MAX44000_DRV_NAME "max44000"25 26/* Registers in datasheet order */27#define MAX44000_REG_STATUS 0x0028#define MAX44000_REG_CFG_MAIN 0x0129#define MAX44000_REG_CFG_RX 0x0230#define MAX44000_REG_CFG_TX 0x0331#define MAX44000_REG_ALS_DATA_HI 0x0432#define MAX44000_REG_ALS_DATA_LO 0x0533#define MAX44000_REG_PRX_DATA 0x1634#define MAX44000_REG_ALS_UPTHR_HI 0x0635#define MAX44000_REG_ALS_UPTHR_LO 0x0736#define MAX44000_REG_ALS_LOTHR_HI 0x0837#define MAX44000_REG_ALS_LOTHR_LO 0x0938#define MAX44000_REG_PST 0x0a39#define MAX44000_REG_PRX_IND 0x0b40#define MAX44000_REG_PRX_THR 0x0c41#define MAX44000_REG_TRIM_GAIN_GREEN 0x0f42#define MAX44000_REG_TRIM_GAIN_IR 0x1043 44/* REG_CFG bits */45#define MAX44000_CFG_ALSINTE 0x0146#define MAX44000_CFG_PRXINTE 0x0247#define MAX44000_CFG_MASK 0x1c48#define MAX44000_CFG_MODE_SHUTDOWN 0x0049#define MAX44000_CFG_MODE_ALS_GIR 0x0450#define MAX44000_CFG_MODE_ALS_G 0x0851#define MAX44000_CFG_MODE_ALS_IR 0x0c52#define MAX44000_CFG_MODE_ALS_PRX 0x1053#define MAX44000_CFG_MODE_PRX 0x1454#define MAX44000_CFG_TRIM 0x2055 56/*57 * Upper 4 bits are not documented but start as 1 on powerup58 * Setting them to 0 causes proximity to misbehave so set them to 159 */60#define MAX44000_REG_CFG_RX_DEFAULT 0xf061 62/* REG_RX bits */63#define MAX44000_CFG_RX_ALSTIM_MASK 0x0c64#define MAX44000_CFG_RX_ALSTIM_SHIFT 265#define MAX44000_CFG_RX_ALSPGA_MASK 0x0366#define MAX44000_CFG_RX_ALSPGA_SHIFT 067 68/* REG_TX bits */69#define MAX44000_LED_CURRENT_MASK 0xf70#define MAX44000_LED_CURRENT_MAX 1171#define MAX44000_LED_CURRENT_DEFAULT 672 73#define MAX44000_ALSDATA_OVERFLOW 0x400074 75struct max44000_data {76 struct mutex lock;77 struct regmap *regmap;78 /* Ensure naturally aligned timestamp */79 struct {80 u16 channels[2];81 s64 ts __aligned(8);82 } scan;83};84 85/* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */86#define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 587 88/* Scale can be multiplied by up to 128x via ALSPGA for measurement gain */89static const int max44000_alspga_shift[] = {0, 2, 4, 7};90#define MAX44000_ALSPGA_MAX_SHIFT 791 92/*93 * Scale can be multiplied by up to 64x via ALSTIM because of lost resolution94 *95 * This scaling factor is hidden from userspace and instead accounted for when96 * reading raw values from the device.97 *98 * This makes it possible to cleanly expose ALSPGA as IIO_CHAN_INFO_SCALE and99 * ALSTIM as IIO_CHAN_INFO_INT_TIME without the values affecting each other.100 *101 * Handling this internally is also required for buffer support because the102 * channel's scan_type can't be modified dynamically.103 */104#define MAX44000_ALSTIM_SHIFT(alstim) (2 * (alstim))105 106/* Available integration times with pretty manual alignment: */107static const int max44000_int_time_avail_ns_array[] = {108 100000000,109 25000000,110 6250000,111 1562500,112};113static const char max44000_int_time_avail_str[] =114 "0.100 "115 "0.025 "116 "0.00625 "117 "0.0015625";118 119/* Available scales (internal to ulux) with pretty manual alignment: */120static const int max44000_scale_avail_ulux_array[] = {121 31250,122 125000,123 500000,124 4000000,125};126static const char max44000_scale_avail_str[] =127 "0.03125 "128 "0.125 "129 "0.5 "130 "4";131 132#define MAX44000_SCAN_INDEX_ALS 0133#define MAX44000_SCAN_INDEX_PRX 1134 135static const struct iio_chan_spec max44000_channels[] = {136 {137 .type = IIO_LIGHT,138 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),139 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |140 BIT(IIO_CHAN_INFO_INT_TIME),141 .scan_index = MAX44000_SCAN_INDEX_ALS,142 .scan_type = {143 .sign = 'u',144 .realbits = 14,145 .storagebits = 16,146 }147 },148 {149 .type = IIO_PROXIMITY,150 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),151 .scan_index = MAX44000_SCAN_INDEX_PRX,152 .scan_type = {153 .sign = 'u',154 .realbits = 8,155 .storagebits = 16,156 }157 },158 IIO_CHAN_SOFT_TIMESTAMP(2),159 {160 .type = IIO_CURRENT,161 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |162 BIT(IIO_CHAN_INFO_SCALE),163 .extend_name = "led",164 .output = 1,165 .scan_index = -1,166 },167};168 169static int max44000_read_alstim(struct max44000_data *data)170{171 unsigned int val;172 int ret;173 174 ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);175 if (ret < 0)176 return ret;177 return (val & MAX44000_CFG_RX_ALSTIM_MASK) >> MAX44000_CFG_RX_ALSTIM_SHIFT;178}179 180static int max44000_write_alstim(struct max44000_data *data, int val)181{182 return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,183 MAX44000_CFG_RX_ALSTIM_MASK,184 val << MAX44000_CFG_RX_ALSTIM_SHIFT);185}186 187static int max44000_read_alspga(struct max44000_data *data)188{189 unsigned int val;190 int ret;191 192 ret = regmap_read(data->regmap, MAX44000_REG_CFG_RX, &val);193 if (ret < 0)194 return ret;195 return (val & MAX44000_CFG_RX_ALSPGA_MASK) >> MAX44000_CFG_RX_ALSPGA_SHIFT;196}197 198static int max44000_write_alspga(struct max44000_data *data, int val)199{200 return regmap_write_bits(data->regmap, MAX44000_REG_CFG_RX,201 MAX44000_CFG_RX_ALSPGA_MASK,202 val << MAX44000_CFG_RX_ALSPGA_SHIFT);203}204 205static int max44000_read_alsval(struct max44000_data *data)206{207 u16 regval;208 __be16 val;209 int alstim, ret;210 211 ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI,212 &val, sizeof(val));213 if (ret < 0)214 return ret;215 alstim = ret = max44000_read_alstim(data);216 if (ret < 0)217 return ret;218 219 regval = be16_to_cpu(val);220 221 /*222 * Overflow is explained on datasheet page 17.223 *224 * It's a warning that either the G or IR channel has become saturated225 * and that the value in the register is likely incorrect.226 *227 * The recommendation is to change the scale (ALSPGA).228 * The driver just returns the max representable value.229 */230 if (regval & MAX44000_ALSDATA_OVERFLOW)231 return 0x3FFF;232 233 return regval << MAX44000_ALSTIM_SHIFT(alstim);234}235 236static int max44000_write_led_current_raw(struct max44000_data *data, int val)237{238 /* Maybe we should clamp the value instead? */239 if (val < 0 || val > MAX44000_LED_CURRENT_MAX)240 return -ERANGE;241 if (val >= 8)242 val += 4;243 return regmap_write_bits(data->regmap, MAX44000_REG_CFG_TX,244 MAX44000_LED_CURRENT_MASK, val);245}246 247static int max44000_read_led_current_raw(struct max44000_data *data)248{249 unsigned int regval;250 int ret;251 252 ret = regmap_read(data->regmap, MAX44000_REG_CFG_TX, ®val);253 if (ret < 0)254 return ret;255 regval &= MAX44000_LED_CURRENT_MASK;256 if (regval >= 8)257 regval -= 4;258 return regval;259}260 261static int max44000_read_raw(struct iio_dev *indio_dev,262 struct iio_chan_spec const *chan,263 int *val, int *val2, long mask)264{265 struct max44000_data *data = iio_priv(indio_dev);266 int alstim, alspga;267 unsigned int regval;268 int ret;269 270 switch (mask) {271 case IIO_CHAN_INFO_RAW:272 switch (chan->type) {273 case IIO_LIGHT:274 mutex_lock(&data->lock);275 ret = max44000_read_alsval(data);276 mutex_unlock(&data->lock);277 if (ret < 0)278 return ret;279 *val = ret;280 return IIO_VAL_INT;281 282 case IIO_PROXIMITY:283 mutex_lock(&data->lock);284 ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, ®val);285 mutex_unlock(&data->lock);286 if (ret < 0)287 return ret;288 *val = regval;289 return IIO_VAL_INT;290 291 case IIO_CURRENT:292 mutex_lock(&data->lock);293 ret = max44000_read_led_current_raw(data);294 mutex_unlock(&data->lock);295 if (ret < 0)296 return ret;297 *val = ret;298 return IIO_VAL_INT;299 300 default:301 return -EINVAL;302 }303 304 case IIO_CHAN_INFO_SCALE:305 switch (chan->type) {306 case IIO_CURRENT:307 /* Output register is in 10s of miliamps */308 *val = 10;309 return IIO_VAL_INT;310 311 case IIO_LIGHT:312 mutex_lock(&data->lock);313 alspga = ret = max44000_read_alspga(data);314 mutex_unlock(&data->lock);315 if (ret < 0)316 return ret;317 318 /* Avoid negative shifts */319 *val = (1 << MAX44000_ALSPGA_MAX_SHIFT);320 *val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2321 + MAX44000_ALSPGA_MAX_SHIFT322 - max44000_alspga_shift[alspga];323 return IIO_VAL_FRACTIONAL_LOG2;324 325 default:326 return -EINVAL;327 }328 329 case IIO_CHAN_INFO_INT_TIME:330 mutex_lock(&data->lock);331 alstim = ret = max44000_read_alstim(data);332 mutex_unlock(&data->lock);333 334 if (ret < 0)335 return ret;336 *val = 0;337 *val2 = max44000_int_time_avail_ns_array[alstim];338 return IIO_VAL_INT_PLUS_NANO;339 340 default:341 return -EINVAL;342 }343}344 345static int max44000_write_raw(struct iio_dev *indio_dev,346 struct iio_chan_spec const *chan,347 int val, int val2, long mask)348{349 struct max44000_data *data = iio_priv(indio_dev);350 int ret;351 352 if (mask == IIO_CHAN_INFO_RAW && chan->type == IIO_CURRENT) {353 mutex_lock(&data->lock);354 ret = max44000_write_led_current_raw(data, val);355 mutex_unlock(&data->lock);356 return ret;357 } else if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT) {358 s64 valns = val * NSEC_PER_SEC + val2;359 int alstim = find_closest_descending(valns,360 max44000_int_time_avail_ns_array,361 ARRAY_SIZE(max44000_int_time_avail_ns_array));362 mutex_lock(&data->lock);363 ret = max44000_write_alstim(data, alstim);364 mutex_unlock(&data->lock);365 return ret;366 } else if (mask == IIO_CHAN_INFO_SCALE && chan->type == IIO_LIGHT) {367 s64 valus = val * USEC_PER_SEC + val2;368 int alspga = find_closest(valus,369 max44000_scale_avail_ulux_array,370 ARRAY_SIZE(max44000_scale_avail_ulux_array));371 mutex_lock(&data->lock);372 ret = max44000_write_alspga(data, alspga);373 mutex_unlock(&data->lock);374 return ret;375 }376 377 return -EINVAL;378}379 380static int max44000_write_raw_get_fmt(struct iio_dev *indio_dev,381 struct iio_chan_spec const *chan,382 long mask)383{384 if (mask == IIO_CHAN_INFO_INT_TIME && chan->type == IIO_LIGHT)385 return IIO_VAL_INT_PLUS_NANO;386 else if (mask == IIO_CHAN_INFO_SCALE && chan->type == IIO_LIGHT)387 return IIO_VAL_INT_PLUS_MICRO;388 else389 return IIO_VAL_INT;390}391 392static IIO_CONST_ATTR(illuminance_integration_time_available, max44000_int_time_avail_str);393static IIO_CONST_ATTR(illuminance_scale_available, max44000_scale_avail_str);394 395static struct attribute *max44000_attributes[] = {396 &iio_const_attr_illuminance_integration_time_available.dev_attr.attr,397 &iio_const_attr_illuminance_scale_available.dev_attr.attr,398 NULL399};400 401static const struct attribute_group max44000_attribute_group = {402 .attrs = max44000_attributes,403};404 405static const struct iio_info max44000_info = {406 .read_raw = max44000_read_raw,407 .write_raw = max44000_write_raw,408 .write_raw_get_fmt = max44000_write_raw_get_fmt,409 .attrs = &max44000_attribute_group,410};411 412static bool max44000_readable_reg(struct device *dev, unsigned int reg)413{414 switch (reg) {415 case MAX44000_REG_STATUS:416 case MAX44000_REG_CFG_MAIN:417 case MAX44000_REG_CFG_RX:418 case MAX44000_REG_CFG_TX:419 case MAX44000_REG_ALS_DATA_HI:420 case MAX44000_REG_ALS_DATA_LO:421 case MAX44000_REG_PRX_DATA:422 case MAX44000_REG_ALS_UPTHR_HI:423 case MAX44000_REG_ALS_UPTHR_LO:424 case MAX44000_REG_ALS_LOTHR_HI:425 case MAX44000_REG_ALS_LOTHR_LO:426 case MAX44000_REG_PST:427 case MAX44000_REG_PRX_IND:428 case MAX44000_REG_PRX_THR:429 case MAX44000_REG_TRIM_GAIN_GREEN:430 case MAX44000_REG_TRIM_GAIN_IR:431 return true;432 default:433 return false;434 }435}436 437static bool max44000_writeable_reg(struct device *dev, unsigned int reg)438{439 switch (reg) {440 case MAX44000_REG_CFG_MAIN:441 case MAX44000_REG_CFG_RX:442 case MAX44000_REG_CFG_TX:443 case MAX44000_REG_ALS_UPTHR_HI:444 case MAX44000_REG_ALS_UPTHR_LO:445 case MAX44000_REG_ALS_LOTHR_HI:446 case MAX44000_REG_ALS_LOTHR_LO:447 case MAX44000_REG_PST:448 case MAX44000_REG_PRX_IND:449 case MAX44000_REG_PRX_THR:450 case MAX44000_REG_TRIM_GAIN_GREEN:451 case MAX44000_REG_TRIM_GAIN_IR:452 return true;453 default:454 return false;455 }456}457 458static bool max44000_volatile_reg(struct device *dev, unsigned int reg)459{460 switch (reg) {461 case MAX44000_REG_STATUS:462 case MAX44000_REG_ALS_DATA_HI:463 case MAX44000_REG_ALS_DATA_LO:464 case MAX44000_REG_PRX_DATA:465 return true;466 default:467 return false;468 }469}470 471static bool max44000_precious_reg(struct device *dev, unsigned int reg)472{473 return reg == MAX44000_REG_STATUS;474}475 476static const struct regmap_config max44000_regmap_config = {477 .reg_bits = 8,478 .val_bits = 8,479 480 .max_register = MAX44000_REG_PRX_DATA,481 .readable_reg = max44000_readable_reg,482 .writeable_reg = max44000_writeable_reg,483 .volatile_reg = max44000_volatile_reg,484 .precious_reg = max44000_precious_reg,485 486 .use_single_read = true,487 .use_single_write = true,488 .cache_type = REGCACHE_RBTREE,489};490 491static irqreturn_t max44000_trigger_handler(int irq, void *p)492{493 struct iio_poll_func *pf = p;494 struct iio_dev *indio_dev = pf->indio_dev;495 struct max44000_data *data = iio_priv(indio_dev);496 int index = 0;497 unsigned int regval;498 int ret;499 500 mutex_lock(&data->lock);501 if (test_bit(MAX44000_SCAN_INDEX_ALS, indio_dev->active_scan_mask)) {502 ret = max44000_read_alsval(data);503 if (ret < 0)504 goto out_unlock;505 data->scan.channels[index++] = ret;506 }507 if (test_bit(MAX44000_SCAN_INDEX_PRX, indio_dev->active_scan_mask)) {508 ret = regmap_read(data->regmap, MAX44000_REG_PRX_DATA, ®val);509 if (ret < 0)510 goto out_unlock;511 data->scan.channels[index] = regval;512 }513 mutex_unlock(&data->lock);514 515 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,516 iio_get_time_ns(indio_dev));517 iio_trigger_notify_done(indio_dev->trig);518 return IRQ_HANDLED;519 520out_unlock:521 mutex_unlock(&data->lock);522 iio_trigger_notify_done(indio_dev->trig);523 return IRQ_HANDLED;524}525 526static int max44000_probe(struct i2c_client *client)527{528 struct max44000_data *data;529 struct iio_dev *indio_dev;530 int ret, reg;531 532 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));533 if (!indio_dev)534 return -ENOMEM;535 data = iio_priv(indio_dev);536 data->regmap = devm_regmap_init_i2c(client, &max44000_regmap_config);537 if (IS_ERR(data->regmap)) {538 dev_err(&client->dev, "regmap_init failed!\n");539 return PTR_ERR(data->regmap);540 }541 542 mutex_init(&data->lock);543 indio_dev->info = &max44000_info;544 indio_dev->name = MAX44000_DRV_NAME;545 indio_dev->channels = max44000_channels;546 indio_dev->num_channels = ARRAY_SIZE(max44000_channels);547 548 /*549 * The device doesn't have a reset function so we just clear some550 * important bits at probe time to ensure sane operation.551 *552 * Since we don't support interrupts/events the threshold values are553 * not important. We also don't touch trim values.554 */555 556 /* Reset ALS scaling bits */557 ret = regmap_write(data->regmap, MAX44000_REG_CFG_RX,558 MAX44000_REG_CFG_RX_DEFAULT);559 if (ret < 0) {560 dev_err(&client->dev, "failed to write default CFG_RX: %d\n",561 ret);562 return ret;563 }564 565 /*566 * By default the LED pulse used for the proximity sensor is disabled.567 * Set a middle value so that we get some sort of valid data by default.568 */569 ret = max44000_write_led_current_raw(data, MAX44000_LED_CURRENT_DEFAULT);570 if (ret < 0) {571 dev_err(&client->dev, "failed to write init config: %d\n", ret);572 return ret;573 }574 575 /* Reset CFG bits to ALS_PRX mode which allows easy reading of both values. */576 reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_PRX;577 ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);578 if (ret < 0) {579 dev_err(&client->dev, "failed to write init config: %d\n", ret);580 return ret;581 }582 583 /* Read status at least once to clear any stale interrupt bits. */584 ret = regmap_read(data->regmap, MAX44000_REG_STATUS, ®);585 if (ret < 0) {586 dev_err(&client->dev, "failed to read init status: %d\n", ret);587 return ret;588 }589 590 ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,591 max44000_trigger_handler, NULL);592 if (ret < 0) {593 dev_err(&client->dev, "iio triggered buffer setup failed\n");594 return ret;595 }596 597 return devm_iio_device_register(&client->dev, indio_dev);598}599 600static const struct i2c_device_id max44000_id[] = {601 { "max44000" },602 { }603};604MODULE_DEVICE_TABLE(i2c, max44000_id);605 606static const struct acpi_device_id max44000_acpi_match[] = {607 {"MAX44000", 0},608 { }609};610MODULE_DEVICE_TABLE(acpi, max44000_acpi_match);611 612static struct i2c_driver max44000_driver = {613 .driver = {614 .name = MAX44000_DRV_NAME,615 .acpi_match_table = max44000_acpi_match,616 },617 .probe = max44000_probe,618 .id_table = max44000_id,619};620 621module_i2c_driver(max44000_driver);622 623MODULE_AUTHOR("Crestez Dan Leonard <leonard.crestez@intel.com>");624MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor");625MODULE_LICENSE("GPL v2");626