553 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2013 Capella Microsystems Inc.4 * Author: Kevin Tsai <ktsai@capellamicro.com>5 */6 7#include <linux/acpi.h>8#include <linux/delay.h>9#include <linux/err.h>10#include <linux/i2c.h>11#include <linux/mutex.h>12#include <linux/module.h>13#include <linux/mod_devicetable.h>14#include <linux/interrupt.h>15#include <linux/regulator/consumer.h>16#include <linux/iio/iio.h>17#include <linux/iio/sysfs.h>18#include <linux/iio/events.h>19#include <linux/init.h>20 21/* Registers Address */22#define CM32181_REG_ADDR_CMD 0x0023#define CM32181_REG_ADDR_WH 0x0124#define CM32181_REG_ADDR_WL 0x0225#define CM32181_REG_ADDR_TEST 0x0326#define CM32181_REG_ADDR_ALS 0x0427#define CM32181_REG_ADDR_STATUS 0x0628#define CM32181_REG_ADDR_ID 0x0729 30/* Number of Configurable Registers */31#define CM32181_CONF_REG_NUM 432 33/* CMD register */34#define CM32181_CMD_ALS_DISABLE BIT(0)35#define CM32181_CMD_ALS_INT_EN BIT(1)36#define CM32181_CMD_ALS_THRES_WINDOW BIT(2)37 38#define CM32181_CMD_ALS_PERS_SHIFT 439#define CM32181_CMD_ALS_PERS_MASK (0x03 << CM32181_CMD_ALS_PERS_SHIFT)40#define CM32181_CMD_ALS_PERS_DEFAULT (0x01 << CM32181_CMD_ALS_PERS_SHIFT)41 42#define CM32181_CMD_ALS_IT_SHIFT 643#define CM32181_CMD_ALS_IT_MASK (0x0F << CM32181_CMD_ALS_IT_SHIFT)44#define CM32181_CMD_ALS_IT_DEFAULT (0x00 << CM32181_CMD_ALS_IT_SHIFT)45 46#define CM32181_CMD_ALS_SM_SHIFT 1147#define CM32181_CMD_ALS_SM_MASK (0x03 << CM32181_CMD_ALS_SM_SHIFT)48#define CM32181_CMD_ALS_SM_DEFAULT (0x01 << CM32181_CMD_ALS_SM_SHIFT)49 50#define CM32181_LUX_PER_BIT 500 /* ALS_SM=01 IT=800ms */51#define CM32181_LUX_PER_BIT_RESOLUTION 10000052#define CM32181_LUX_PER_BIT_BASE_IT 800000 /* Based on IT=800ms */53#define CM32181_CALIBSCALE_DEFAULT 10000054#define CM32181_CALIBSCALE_RESOLUTION 10000055 56#define SMBUS_ALERT_RESPONSE_ADDRESS 0x0c57 58/* CPM0 Index 0: device-id (3218 or 32181), 1: Unknown, 2: init_regs_bitmap */59#define CPM0_REGS_BITMAP 260#define CPM0_HEADER_SIZE 361 62/* CPM1 Index 0: lux_per_bit, 1: calibscale, 2: resolution (100000) */63#define CPM1_LUX_PER_BIT 064#define CPM1_CALIBSCALE 165#define CPM1_SIZE 366 67/* CM3218 Family */68static const int cm3218_als_it_bits[] = { 0, 1, 2, 3 };69static const int cm3218_als_it_values[] = { 100000, 200000, 400000, 800000 };70 71/* CM32181 Family */72static const int cm32181_als_it_bits[] = { 12, 8, 0, 1, 2, 3 };73static const int cm32181_als_it_values[] = {74 25000, 50000, 100000, 200000, 400000, 80000075};76 77struct cm32181_chip {78 struct i2c_client *client;79 struct device *dev;80 struct mutex lock;81 u16 conf_regs[CM32181_CONF_REG_NUM];82 unsigned long init_regs_bitmap;83 int calibscale;84 int lux_per_bit;85 int lux_per_bit_base_it;86 int num_als_it;87 const int *als_it_bits;88 const int *als_it_values;89};90 91static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2);92 93#ifdef CONFIG_ACPI94/**95 * cm32181_acpi_get_cpm() - Get CPM object from ACPI96 * @dev: pointer of struct device.97 * @obj_name: pointer of ACPI object name.98 * @values: pointer of array for return elements.99 * @count: maximum size of return array.100 *101 * Convert ACPI CPM table to array.102 *103 * Return: -ENODEV for fail. Otherwise is number of elements.104 */105static int cm32181_acpi_get_cpm(struct device *dev, char *obj_name,106 u64 *values, int count)107{108 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };109 union acpi_object *cpm, *elem;110 acpi_handle handle;111 acpi_status status;112 int i;113 114 handle = ACPI_HANDLE(dev);115 if (!handle)116 return -ENODEV;117 118 status = acpi_evaluate_object(handle, obj_name, NULL, &buffer);119 if (ACPI_FAILURE(status)) {120 dev_err(dev, "object %s not found\n", obj_name);121 return -ENODEV;122 }123 124 cpm = buffer.pointer;125 if (cpm->package.count > count)126 dev_warn(dev, "%s table contains %u values, only using first %d values\n",127 obj_name, cpm->package.count, count);128 129 count = min_t(int, cpm->package.count, count);130 for (i = 0; i < count; i++) {131 elem = &(cpm->package.elements[i]);132 values[i] = elem->integer.value;133 }134 135 kfree(buffer.pointer);136 137 return count;138}139 140static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)141{142 u64 vals[CPM0_HEADER_SIZE + CM32181_CONF_REG_NUM];143 struct device *dev = cm32181->dev;144 int i, count;145 146 count = cm32181_acpi_get_cpm(dev, "CPM0", vals, ARRAY_SIZE(vals));147 if (count <= CPM0_HEADER_SIZE)148 return;149 150 count -= CPM0_HEADER_SIZE;151 152 cm32181->init_regs_bitmap = vals[CPM0_REGS_BITMAP];153 cm32181->init_regs_bitmap &= GENMASK(count - 1, 0);154 for_each_set_bit(i, &cm32181->init_regs_bitmap, count)155 cm32181->conf_regs[i] = vals[CPM0_HEADER_SIZE + i];156 157 count = cm32181_acpi_get_cpm(dev, "CPM1", vals, ARRAY_SIZE(vals));158 if (count != CPM1_SIZE)159 return;160 161 cm32181->lux_per_bit = vals[CPM1_LUX_PER_BIT];162 163 /* Check for uncalibrated devices */164 if (vals[CPM1_CALIBSCALE] == CM32181_CALIBSCALE_DEFAULT)165 return;166 167 cm32181->calibscale = vals[CPM1_CALIBSCALE];168 /* CPM1 lux_per_bit is for the current it value */169 cm32181_read_als_it(cm32181, &cm32181->lux_per_bit_base_it);170}171#else172static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)173{174}175#endif /* CONFIG_ACPI */176 177/**178 * cm32181_reg_init() - Initialize CM32181 registers179 * @cm32181: pointer of struct cm32181.180 *181 * Initialize CM32181 ambient light sensor register to default values.182 *183 * Return: 0 for success; otherwise for error code.184 */185static int cm32181_reg_init(struct cm32181_chip *cm32181)186{187 struct i2c_client *client = cm32181->client;188 int i;189 s32 ret;190 191 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID);192 if (ret < 0)193 return ret;194 195 /* check device ID */196 switch (ret & 0xFF) {197 case 0x18: /* CM3218 */198 cm32181->num_als_it = ARRAY_SIZE(cm3218_als_it_bits);199 cm32181->als_it_bits = cm3218_als_it_bits;200 cm32181->als_it_values = cm3218_als_it_values;201 break;202 case 0x81: /* CM32181 */203 case 0x82: /* CM32182, fully compat. with CM32181 */204 cm32181->num_als_it = ARRAY_SIZE(cm32181_als_it_bits);205 cm32181->als_it_bits = cm32181_als_it_bits;206 cm32181->als_it_values = cm32181_als_it_values;207 break;208 default:209 return -ENODEV;210 }211 212 /* Default Values */213 cm32181->conf_regs[CM32181_REG_ADDR_CMD] =214 CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT;215 cm32181->init_regs_bitmap = BIT(CM32181_REG_ADDR_CMD);216 cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT;217 cm32181->lux_per_bit = CM32181_LUX_PER_BIT;218 cm32181->lux_per_bit_base_it = CM32181_LUX_PER_BIT_BASE_IT;219 220 if (ACPI_HANDLE(cm32181->dev))221 cm32181_acpi_parse_cpm_tables(cm32181);222 223 /* Initialize registers*/224 for_each_set_bit(i, &cm32181->init_regs_bitmap, CM32181_CONF_REG_NUM) {225 ret = i2c_smbus_write_word_data(client, i,226 cm32181->conf_regs[i]);227 if (ret < 0)228 return ret;229 }230 231 return 0;232}233 234/**235 * cm32181_read_als_it() - Get sensor integration time (ms)236 * @cm32181: pointer of struct cm32181237 * @val2: pointer of int to load the als_it value.238 *239 * Report the current integration time in milliseconds.240 *241 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.242 */243static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2)244{245 u16 als_it;246 int i;247 248 als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD];249 als_it &= CM32181_CMD_ALS_IT_MASK;250 als_it >>= CM32181_CMD_ALS_IT_SHIFT;251 for (i = 0; i < cm32181->num_als_it; i++) {252 if (als_it == cm32181->als_it_bits[i]) {253 *val2 = cm32181->als_it_values[i];254 return IIO_VAL_INT_PLUS_MICRO;255 }256 }257 258 return -EINVAL;259}260 261/**262 * cm32181_write_als_it() - Write sensor integration time263 * @cm32181: pointer of struct cm32181.264 * @val: integration time by millisecond.265 *266 * Convert integration time (ms) to sensor value.267 *268 * Return: i2c_smbus_write_word_data command return value.269 */270static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val)271{272 struct i2c_client *client = cm32181->client;273 u16 als_it;274 int ret, i, n;275 276 n = cm32181->num_als_it;277 for (i = 0; i < n; i++)278 if (val <= cm32181->als_it_values[i])279 break;280 if (i >= n)281 i = n - 1;282 283 als_it = cm32181->als_it_bits[i];284 als_it <<= CM32181_CMD_ALS_IT_SHIFT;285 286 mutex_lock(&cm32181->lock);287 cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=288 ~CM32181_CMD_ALS_IT_MASK;289 cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=290 als_it;291 ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,292 cm32181->conf_regs[CM32181_REG_ADDR_CMD]);293 mutex_unlock(&cm32181->lock);294 295 return ret;296}297 298/**299 * cm32181_get_lux() - report current lux value300 * @cm32181: pointer of struct cm32181.301 *302 * Convert sensor raw data to lux. It depends on integration303 * time and calibscale variable.304 *305 * Return: Positive value is lux, otherwise is error code.306 */307static int cm32181_get_lux(struct cm32181_chip *cm32181)308{309 struct i2c_client *client = cm32181->client;310 int ret;311 int als_it;312 u64 lux;313 314 ret = cm32181_read_als_it(cm32181, &als_it);315 if (ret < 0)316 return -EINVAL;317 318 lux = cm32181->lux_per_bit;319 lux *= cm32181->lux_per_bit_base_it;320 lux = div_u64(lux, als_it);321 322 ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);323 if (ret < 0)324 return ret;325 326 lux *= ret;327 lux *= cm32181->calibscale;328 lux = div_u64(lux, CM32181_CALIBSCALE_RESOLUTION);329 lux = div_u64(lux, CM32181_LUX_PER_BIT_RESOLUTION);330 331 if (lux > 0xFFFF)332 lux = 0xFFFF;333 334 return lux;335}336 337static int cm32181_read_raw(struct iio_dev *indio_dev,338 struct iio_chan_spec const *chan,339 int *val, int *val2, long mask)340{341 struct cm32181_chip *cm32181 = iio_priv(indio_dev);342 int ret;343 344 switch (mask) {345 case IIO_CHAN_INFO_PROCESSED:346 ret = cm32181_get_lux(cm32181);347 if (ret < 0)348 return ret;349 *val = ret;350 return IIO_VAL_INT;351 case IIO_CHAN_INFO_CALIBSCALE:352 *val = cm32181->calibscale;353 return IIO_VAL_INT;354 case IIO_CHAN_INFO_INT_TIME:355 *val = 0;356 ret = cm32181_read_als_it(cm32181, val2);357 return ret;358 }359 360 return -EINVAL;361}362 363static int cm32181_write_raw(struct iio_dev *indio_dev,364 struct iio_chan_spec const *chan,365 int val, int val2, long mask)366{367 struct cm32181_chip *cm32181 = iio_priv(indio_dev);368 int ret;369 370 switch (mask) {371 case IIO_CHAN_INFO_CALIBSCALE:372 cm32181->calibscale = val;373 return val;374 case IIO_CHAN_INFO_INT_TIME:375 ret = cm32181_write_als_it(cm32181, val2);376 return ret;377 }378 379 return -EINVAL;380}381 382/**383 * cm32181_get_it_available() - Get available ALS IT value384 * @dev: pointer of struct device.385 * @attr: pointer of struct device_attribute.386 * @buf: pointer of return string buffer.387 *388 * Display the available integration time values by millisecond.389 *390 * Return: string length.391 */392static ssize_t cm32181_get_it_available(struct device *dev,393 struct device_attribute *attr, char *buf)394{395 struct cm32181_chip *cm32181 = iio_priv(dev_to_iio_dev(dev));396 int i, n, len;397 398 n = cm32181->num_als_it;399 for (i = 0, len = 0; i < n; i++)400 len += sprintf(buf + len, "0.%06u ", cm32181->als_it_values[i]);401 return len + sprintf(buf + len, "\n");402}403 404static const struct iio_chan_spec cm32181_channels[] = {405 {406 .type = IIO_LIGHT,407 .info_mask_separate =408 BIT(IIO_CHAN_INFO_PROCESSED) |409 BIT(IIO_CHAN_INFO_CALIBSCALE) |410 BIT(IIO_CHAN_INFO_INT_TIME),411 }412};413 414static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,415 S_IRUGO, cm32181_get_it_available, NULL, 0);416 417static struct attribute *cm32181_attributes[] = {418 &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,419 NULL,420};421 422static const struct attribute_group cm32181_attribute_group = {423 .attrs = cm32181_attributes424};425 426static const struct iio_info cm32181_info = {427 .read_raw = &cm32181_read_raw,428 .write_raw = &cm32181_write_raw,429 .attrs = &cm32181_attribute_group,430};431 432static void cm32181_unregister_dummy_client(void *data)433{434 struct i2c_client *client = data;435 436 /* Unregister the dummy client */437 i2c_unregister_device(client);438}439 440static int cm32181_probe(struct i2c_client *client)441{442 struct device *dev = &client->dev;443 struct cm32181_chip *cm32181;444 struct iio_dev *indio_dev;445 int ret;446 447 indio_dev = devm_iio_device_alloc(dev, sizeof(*cm32181));448 if (!indio_dev)449 return -ENOMEM;450 451 i2c_set_clientdata(client, indio_dev);452 453 /*454 * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the455 * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address.456 * Detect this and take the following step to deal with it:457 * 1. When a SMBus Alert capable sensor has an Alert asserted, it will458 * not respond on its actual I2C address. Read a byte from the ARA459 * to clear any pending Alerts.460 * 2. Create a "dummy" client for the actual I2C address and461 * use that client to communicate with the sensor.462 */463 if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) {464 struct i2c_board_info board_info = { .type = "dummy" };465 466 i2c_smbus_read_byte(client);467 468 client = i2c_acpi_new_device(dev, 1, &board_info);469 if (IS_ERR(client))470 return PTR_ERR(client);471 472 ret = devm_add_action_or_reset(dev, cm32181_unregister_dummy_client, client);473 if (ret)474 return ret;475 }476 477 cm32181 = iio_priv(indio_dev);478 cm32181->client = client;479 cm32181->dev = dev;480 481 mutex_init(&cm32181->lock);482 indio_dev->channels = cm32181_channels;483 indio_dev->num_channels = ARRAY_SIZE(cm32181_channels);484 indio_dev->info = &cm32181_info;485 indio_dev->name = dev_name(dev);486 indio_dev->modes = INDIO_DIRECT_MODE;487 488 ret = cm32181_reg_init(cm32181);489 if (ret) {490 dev_err(dev, "%s: register init failed\n", __func__);491 return ret;492 }493 494 ret = devm_iio_device_register(dev, indio_dev);495 if (ret) {496 dev_err(dev, "%s: regist device failed\n", __func__);497 return ret;498 }499 500 return 0;501}502 503static int cm32181_suspend(struct device *dev)504{505 struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));506 struct i2c_client *client = cm32181->client;507 508 return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,509 CM32181_CMD_ALS_DISABLE);510}511 512static int cm32181_resume(struct device *dev)513{514 struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));515 struct i2c_client *client = cm32181->client;516 517 return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,518 cm32181->conf_regs[CM32181_REG_ADDR_CMD]);519}520 521static DEFINE_SIMPLE_DEV_PM_OPS(cm32181_pm_ops, cm32181_suspend, cm32181_resume);522 523static const struct of_device_id cm32181_of_match[] = {524 { .compatible = "capella,cm3218" },525 { .compatible = "capella,cm32181" },526 { }527};528MODULE_DEVICE_TABLE(of, cm32181_of_match);529 530#ifdef CONFIG_ACPI531static const struct acpi_device_id cm32181_acpi_match[] = {532 { "CPLM3218", 0 },533 { }534};535MODULE_DEVICE_TABLE(acpi, cm32181_acpi_match);536#endif537 538static struct i2c_driver cm32181_driver = {539 .driver = {540 .name = "cm32181",541 .acpi_match_table = ACPI_PTR(cm32181_acpi_match),542 .of_match_table = cm32181_of_match,543 .pm = pm_sleep_ptr(&cm32181_pm_ops),544 },545 .probe = cm32181_probe,546};547 548module_i2c_driver(cm32181_driver);549 550MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");551MODULE_DESCRIPTION("CM32181 ambient light sensor driver");552MODULE_LICENSE("GPL");553