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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * CM3232 Ambient Light Sensor4 *5 * Copyright (C) 2014-2015 Capella Microsystems Inc.6 * Author: Kevin Tsai <ktsai@capellamicro.com>7 *8 * IIO driver for CM3232 (7-bit I2C slave address 0x10).9 */10 11#include <linux/i2c.h>12#include <linux/module.h>13#include <linux/mod_devicetable.h>14#include <linux/iio/iio.h>15#include <linux/iio/sysfs.h>16#include <linux/init.h>17 18/* Registers Address */19#define CM3232_REG_ADDR_CMD 0x0020#define CM3232_REG_ADDR_ALS 0x5021#define CM3232_REG_ADDR_ID 0x5322 23#define CM3232_CMD_ALS_DISABLE BIT(0)24 25#define CM3232_CMD_ALS_IT_SHIFT 226#define CM3232_CMD_ALS_IT_MASK (BIT(2) | BIT(3) | BIT(4))27#define CM3232_CMD_ALS_IT_DEFAULT (0x01 << CM3232_CMD_ALS_IT_SHIFT)28 29#define CM3232_CMD_ALS_RESET BIT(6)30 31#define CM3232_CMD_DEFAULT CM3232_CMD_ALS_IT_DEFAULT32 33#define CM3232_HW_ID 0x3234#define CM3232_CALIBSCALE_DEFAULT 10000035#define CM3232_CALIBSCALE_RESOLUTION 10000036#define CM3232_MLUX_PER_LUX 100037 38#define CM3232_MLUX_PER_BIT_DEFAULT 6439#define CM3232_MLUX_PER_BIT_BASE_IT 10000040 41static const struct {42 int val;43 int val2;44 u8 it;45} cm3232_als_it_scales[] = {46 {0, 100000, 0}, /* 0.100000 */47 {0, 200000, 1}, /* 0.200000 */48 {0, 400000, 2}, /* 0.400000 */49 {0, 800000, 3}, /* 0.800000 */50 {1, 600000, 4}, /* 1.600000 */51 {3, 200000, 5}, /* 3.200000 */52};53 54struct cm3232_als_info {55 u8 regs_cmd_default;56 u8 hw_id;57 int calibscale;58 int mlux_per_bit;59 int mlux_per_bit_base_it;60};61 62static struct cm3232_als_info cm3232_als_info_default = {63 .regs_cmd_default = CM3232_CMD_DEFAULT,64 .hw_id = CM3232_HW_ID,65 .calibscale = CM3232_CALIBSCALE_DEFAULT,66 .mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT,67 .mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT,68};69 70struct cm3232_chip {71 struct i2c_client *client;72 struct cm3232_als_info *als_info;73 u8 regs_cmd;74 u16 regs_als;75};76 77/**78 * cm3232_reg_init() - Initialize CM323279 * @chip: pointer of struct cm3232_chip.80 *81 * Check and initialize CM3232 ambient light sensor.82 *83 * Return: 0 for success; otherwise for error code.84 */85static int cm3232_reg_init(struct cm3232_chip *chip)86{87 struct i2c_client *client = chip->client;88 s32 ret;89 90 chip->als_info = &cm3232_als_info_default;91 92 /* Identify device */93 ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);94 if (ret < 0) {95 dev_err(&chip->client->dev, "Error reading addr_id\n");96 return ret;97 }98 99 if ((ret & 0xFF) != chip->als_info->hw_id)100 return -ENODEV;101 102 /* Disable and reset device */103 chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET;104 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,105 chip->regs_cmd);106 if (ret < 0) {107 dev_err(&chip->client->dev, "Error writing reg_cmd\n");108 return ret;109 }110 111 /* Register default value */112 chip->regs_cmd = chip->als_info->regs_cmd_default;113 114 /* Configure register */115 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,116 chip->regs_cmd);117 if (ret < 0)118 dev_err(&chip->client->dev, "Error writing reg_cmd\n");119 120 return ret;121}122 123/**124 * cm3232_read_als_it() - Get sensor integration time125 * @chip: pointer of struct cm3232_chip126 * @val: pointer of int to load the integration (sec).127 * @val2: pointer of int to load the integration time (microsecond).128 *129 * Report the current integration time.130 *131 * Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.132 */133static int cm3232_read_als_it(struct cm3232_chip *chip, int *val, int *val2)134{135 u16 als_it;136 int i;137 138 als_it = chip->regs_cmd;139 als_it &= CM3232_CMD_ALS_IT_MASK;140 als_it >>= CM3232_CMD_ALS_IT_SHIFT;141 for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {142 if (als_it == cm3232_als_it_scales[i].it) {143 *val = cm3232_als_it_scales[i].val;144 *val2 = cm3232_als_it_scales[i].val2;145 return IIO_VAL_INT_PLUS_MICRO;146 }147 }148 149 return -EINVAL;150}151 152/**153 * cm3232_write_als_it() - Write sensor integration time154 * @chip: pointer of struct cm3232_chip.155 * @val: integration time in second.156 * @val2: integration time in microsecond.157 *158 * Convert integration time to sensor value.159 *160 * Return: i2c_smbus_write_byte_data command return value.161 */162static int cm3232_write_als_it(struct cm3232_chip *chip, int val, int val2)163{164 struct i2c_client *client = chip->client;165 u16 als_it, cmd;166 int i;167 s32 ret;168 169 for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {170 if (val == cm3232_als_it_scales[i].val &&171 val2 == cm3232_als_it_scales[i].val2) {172 173 als_it = cm3232_als_it_scales[i].it;174 als_it <<= CM3232_CMD_ALS_IT_SHIFT;175 176 cmd = chip->regs_cmd & ~CM3232_CMD_ALS_IT_MASK;177 cmd |= als_it;178 ret = i2c_smbus_write_byte_data(client,179 CM3232_REG_ADDR_CMD,180 cmd);181 if (ret < 0)182 return ret;183 chip->regs_cmd = cmd;184 return 0;185 }186 }187 return -EINVAL;188}189 190/**191 * cm3232_get_lux() - report current lux value192 * @chip: pointer of struct cm3232_chip.193 *194 * Convert sensor data to lux. It depends on integration195 * time and calibscale variable.196 *197 * Return: Zero or positive value is lux, otherwise error code.198 */199static int cm3232_get_lux(struct cm3232_chip *chip)200{201 struct i2c_client *client = chip->client;202 struct cm3232_als_info *als_info = chip->als_info;203 int ret;204 int val, val2;205 int als_it;206 u64 lux;207 208 /* Calculate mlux per bit based on als_it */209 ret = cm3232_read_als_it(chip, &val, &val2);210 if (ret < 0)211 return -EINVAL;212 als_it = val * 1000000 + val2;213 lux = (__force u64)als_info->mlux_per_bit;214 lux *= als_info->mlux_per_bit_base_it;215 lux = div_u64(lux, als_it);216 217 ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ALS);218 if (ret < 0) {219 dev_err(&client->dev, "Error reading reg_addr_als\n");220 return ret;221 }222 223 chip->regs_als = (u16)ret;224 lux *= chip->regs_als;225 lux *= als_info->calibscale;226 lux = div_u64(lux, CM3232_CALIBSCALE_RESOLUTION);227 lux = div_u64(lux, CM3232_MLUX_PER_LUX);228 229 if (lux > 0xFFFF)230 lux = 0xFFFF;231 232 return (int)lux;233}234 235static int cm3232_read_raw(struct iio_dev *indio_dev,236 struct iio_chan_spec const *chan,237 int *val, int *val2, long mask)238{239 struct cm3232_chip *chip = iio_priv(indio_dev);240 struct cm3232_als_info *als_info = chip->als_info;241 int ret;242 243 switch (mask) {244 case IIO_CHAN_INFO_PROCESSED:245 ret = cm3232_get_lux(chip);246 if (ret < 0)247 return ret;248 *val = ret;249 return IIO_VAL_INT;250 case IIO_CHAN_INFO_CALIBSCALE:251 *val = als_info->calibscale;252 return IIO_VAL_INT;253 case IIO_CHAN_INFO_INT_TIME:254 return cm3232_read_als_it(chip, val, val2);255 }256 257 return -EINVAL;258}259 260static int cm3232_write_raw(struct iio_dev *indio_dev,261 struct iio_chan_spec const *chan,262 int val, int val2, long mask)263{264 struct cm3232_chip *chip = iio_priv(indio_dev);265 struct cm3232_als_info *als_info = chip->als_info;266 267 switch (mask) {268 case IIO_CHAN_INFO_CALIBSCALE:269 als_info->calibscale = val;270 return 0;271 case IIO_CHAN_INFO_INT_TIME:272 return cm3232_write_als_it(chip, val, val2);273 }274 275 return -EINVAL;276}277 278/**279 * cm3232_get_it_available() - Get available ALS IT value280 * @dev: pointer of struct device.281 * @attr: pointer of struct device_attribute.282 * @buf: pointer of return string buffer.283 *284 * Display the available integration time in second.285 *286 * Return: string length.287 */288static ssize_t cm3232_get_it_available(struct device *dev,289 struct device_attribute *attr, char *buf)290{291 int i, len;292 293 for (i = 0, len = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++)294 len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ",295 cm3232_als_it_scales[i].val,296 cm3232_als_it_scales[i].val2);297 return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");298}299 300static const struct iio_chan_spec cm3232_channels[] = {301 {302 .type = IIO_LIGHT,303 .info_mask_separate =304 BIT(IIO_CHAN_INFO_PROCESSED) |305 BIT(IIO_CHAN_INFO_CALIBSCALE) |306 BIT(IIO_CHAN_INFO_INT_TIME),307 }308};309 310static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,311 S_IRUGO, cm3232_get_it_available, NULL, 0);312 313static struct attribute *cm3232_attributes[] = {314 &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,315 NULL,316};317 318static const struct attribute_group cm3232_attribute_group = {319 .attrs = cm3232_attributes320};321 322static const struct iio_info cm3232_info = {323 .read_raw = &cm3232_read_raw,324 .write_raw = &cm3232_write_raw,325 .attrs = &cm3232_attribute_group,326};327 328static int cm3232_probe(struct i2c_client *client)329{330 const struct i2c_device_id *id = i2c_client_get_device_id(client);331 struct cm3232_chip *chip;332 struct iio_dev *indio_dev;333 int ret;334 335 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));336 if (!indio_dev)337 return -ENOMEM;338 339 chip = iio_priv(indio_dev);340 i2c_set_clientdata(client, indio_dev);341 chip->client = client;342 343 indio_dev->channels = cm3232_channels;344 indio_dev->num_channels = ARRAY_SIZE(cm3232_channels);345 indio_dev->info = &cm3232_info;346 indio_dev->name = id->name;347 indio_dev->modes = INDIO_DIRECT_MODE;348 349 ret = cm3232_reg_init(chip);350 if (ret) {351 dev_err(&client->dev,352 "%s: register init failed\n",353 __func__);354 return ret;355 }356 357 return iio_device_register(indio_dev);358}359 360static void cm3232_remove(struct i2c_client *client)361{362 struct iio_dev *indio_dev = i2c_get_clientdata(client);363 364 i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,365 CM3232_CMD_ALS_DISABLE);366 367 iio_device_unregister(indio_dev);368}369 370static const struct i2c_device_id cm3232_id[] = {371 { "cm3232" },372 {}373};374 375static int cm3232_suspend(struct device *dev)376{377 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));378 struct cm3232_chip *chip = iio_priv(indio_dev);379 struct i2c_client *client = chip->client;380 int ret;381 382 chip->regs_cmd |= CM3232_CMD_ALS_DISABLE;383 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,384 chip->regs_cmd);385 386 return ret;387}388 389static int cm3232_resume(struct device *dev)390{391 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));392 struct cm3232_chip *chip = iio_priv(indio_dev);393 struct i2c_client *client = chip->client;394 int ret;395 396 chip->regs_cmd &= ~CM3232_CMD_ALS_DISABLE;397 ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,398 chip->regs_cmd | CM3232_CMD_ALS_RESET);399 400 return ret;401}402 403static DEFINE_SIMPLE_DEV_PM_OPS(cm3232_pm_ops, cm3232_suspend, cm3232_resume);404 405MODULE_DEVICE_TABLE(i2c, cm3232_id);406 407static const struct of_device_id cm3232_of_match[] = {408 {.compatible = "capella,cm3232"},409 {}410};411MODULE_DEVICE_TABLE(of, cm3232_of_match);412 413static struct i2c_driver cm3232_driver = {414 .driver = {415 .name = "cm3232",416 .of_match_table = cm3232_of_match,417 .pm = pm_sleep_ptr(&cm3232_pm_ops),418 },419 .id_table = cm3232_id,420 .probe = cm3232_probe,421 .remove = cm3232_remove,422};423 424module_i2c_driver(cm3232_driver);425 426MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");427MODULE_DESCRIPTION("CM3232 ambient light sensor driver");428MODULE_LICENSE("GPL");429