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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * AL3320A - Dyna Image Ambient Light Sensor4 *5 * Copyright (c) 2014, Intel Corporation.6 *7 * IIO driver for AL3320A (7-bit I2C slave address 0x1C).8 *9 * TODO: interrupt support, thresholds10 * When the driver will get support for interrupt handling, then interrupt11 * will need to be disabled before turning sensor OFF in order to avoid12 * potential races with the interrupt handling.13 */14 15#include <linux/bitfield.h>16#include <linux/i2c.h>17#include <linux/module.h>18#include <linux/mod_devicetable.h>19 20#include <linux/iio/iio.h>21#include <linux/iio/sysfs.h>22 23#define AL3320A_DRV_NAME "al3320a"24 25#define AL3320A_REG_CONFIG 0x0026#define AL3320A_REG_STATUS 0x0127#define AL3320A_REG_INT 0x0228#define AL3320A_REG_WAIT 0x0629#define AL3320A_REG_CONFIG_RANGE 0x0730#define AL3320A_REG_PERSIST 0x0831#define AL3320A_REG_MEAN_TIME 0x0932#define AL3320A_REG_ADUMMY 0x0A33#define AL3320A_REG_DATA_LOW 0x2234 35#define AL3320A_REG_LOW_THRESH_LOW 0x3036#define AL3320A_REG_LOW_THRESH_HIGH 0x3137#define AL3320A_REG_HIGH_THRESH_LOW 0x3238#define AL3320A_REG_HIGH_THRESH_HIGH 0x3339 40#define AL3320A_CONFIG_DISABLE 0x0041#define AL3320A_CONFIG_ENABLE 0x0142 43#define AL3320A_GAIN_MASK GENMASK(2, 1)44 45/* chip params default values */46#define AL3320A_DEFAULT_MEAN_TIME 447#define AL3320A_DEFAULT_WAIT_TIME 0 /* no waiting */48 49#define AL3320A_SCALE_AVAILABLE "0.512 0.128 0.032 0.01"50 51enum al3320a_range {52 AL3320A_RANGE_1, /* 33.28 Klx */53 AL3320A_RANGE_2, /* 8.32 Klx */54 AL3320A_RANGE_3, /* 2.08 Klx */55 AL3320A_RANGE_4 /* 0.65 Klx */56};57 58static const int al3320a_scales[][2] = {59 {0, 512000}, {0, 128000}, {0, 32000}, {0, 10000}60};61 62struct al3320a_data {63 struct i2c_client *client;64};65 66static const struct iio_chan_spec al3320a_channels[] = {67 {68 .type = IIO_LIGHT,69 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |70 BIT(IIO_CHAN_INFO_SCALE),71 }72};73 74static IIO_CONST_ATTR(in_illuminance_scale_available, AL3320A_SCALE_AVAILABLE);75 76static struct attribute *al3320a_attributes[] = {77 &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,78 NULL,79};80 81static const struct attribute_group al3320a_attribute_group = {82 .attrs = al3320a_attributes,83};84 85static int al3320a_set_pwr(struct i2c_client *client, bool pwr)86{87 u8 val = pwr ? AL3320A_CONFIG_ENABLE : AL3320A_CONFIG_DISABLE;88 return i2c_smbus_write_byte_data(client, AL3320A_REG_CONFIG, val);89}90 91static void al3320a_set_pwr_off(void *_data)92{93 struct al3320a_data *data = _data;94 95 al3320a_set_pwr(data->client, false);96}97 98static int al3320a_init(struct al3320a_data *data)99{100 int ret;101 102 ret = al3320a_set_pwr(data->client, true);103 104 if (ret < 0)105 return ret;106 107 ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG_RANGE,108 FIELD_PREP(AL3320A_GAIN_MASK,109 AL3320A_RANGE_3));110 if (ret < 0)111 return ret;112 113 ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_MEAN_TIME,114 AL3320A_DEFAULT_MEAN_TIME);115 if (ret < 0)116 return ret;117 118 ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_WAIT,119 AL3320A_DEFAULT_WAIT_TIME);120 if (ret < 0)121 return ret;122 123 return 0;124}125 126static int al3320a_read_raw(struct iio_dev *indio_dev,127 struct iio_chan_spec const *chan, int *val,128 int *val2, long mask)129{130 struct al3320a_data *data = iio_priv(indio_dev);131 int ret;132 133 switch (mask) {134 case IIO_CHAN_INFO_RAW:135 /*136 * ALS ADC value is stored in two adjacent registers:137 * - low byte of output is stored at AL3320A_REG_DATA_LOW138 * - high byte of output is stored at AL3320A_REG_DATA_LOW + 1139 */140 ret = i2c_smbus_read_word_data(data->client,141 AL3320A_REG_DATA_LOW);142 if (ret < 0)143 return ret;144 *val = ret;145 return IIO_VAL_INT;146 case IIO_CHAN_INFO_SCALE:147 ret = i2c_smbus_read_byte_data(data->client,148 AL3320A_REG_CONFIG_RANGE);149 if (ret < 0)150 return ret;151 152 ret = FIELD_GET(AL3320A_GAIN_MASK, ret);153 *val = al3320a_scales[ret][0];154 *val2 = al3320a_scales[ret][1];155 156 return IIO_VAL_INT_PLUS_MICRO;157 }158 return -EINVAL;159}160 161static int al3320a_write_raw(struct iio_dev *indio_dev,162 struct iio_chan_spec const *chan, int val,163 int val2, long mask)164{165 struct al3320a_data *data = iio_priv(indio_dev);166 int i;167 168 switch (mask) {169 case IIO_CHAN_INFO_SCALE:170 for (i = 0; i < ARRAY_SIZE(al3320a_scales); i++) {171 if (val != al3320a_scales[i][0] ||172 val2 != al3320a_scales[i][1])173 continue;174 175 return i2c_smbus_write_byte_data(data->client,176 AL3320A_REG_CONFIG_RANGE,177 FIELD_PREP(AL3320A_GAIN_MASK, i));178 }179 break;180 }181 return -EINVAL;182}183 184static const struct iio_info al3320a_info = {185 .read_raw = al3320a_read_raw,186 .write_raw = al3320a_write_raw,187 .attrs = &al3320a_attribute_group,188};189 190static int al3320a_probe(struct i2c_client *client)191{192 struct al3320a_data *data;193 struct iio_dev *indio_dev;194 int ret;195 196 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));197 if (!indio_dev)198 return -ENOMEM;199 200 data = iio_priv(indio_dev);201 i2c_set_clientdata(client, indio_dev);202 data->client = client;203 204 indio_dev->info = &al3320a_info;205 indio_dev->name = AL3320A_DRV_NAME;206 indio_dev->channels = al3320a_channels;207 indio_dev->num_channels = ARRAY_SIZE(al3320a_channels);208 indio_dev->modes = INDIO_DIRECT_MODE;209 210 ret = al3320a_init(data);211 if (ret < 0) {212 dev_err(&client->dev, "al3320a chip init failed\n");213 return ret;214 }215 216 ret = devm_add_action_or_reset(&client->dev,217 al3320a_set_pwr_off,218 data);219 if (ret < 0)220 return ret;221 222 return devm_iio_device_register(&client->dev, indio_dev);223}224 225static int al3320a_suspend(struct device *dev)226{227 return al3320a_set_pwr(to_i2c_client(dev), false);228}229 230static int al3320a_resume(struct device *dev)231{232 return al3320a_set_pwr(to_i2c_client(dev), true);233}234 235static DEFINE_SIMPLE_DEV_PM_OPS(al3320a_pm_ops, al3320a_suspend,236 al3320a_resume);237 238static const struct i2c_device_id al3320a_id[] = {239 { "al3320a" },240 {}241};242MODULE_DEVICE_TABLE(i2c, al3320a_id);243 244static const struct of_device_id al3320a_of_match[] = {245 { .compatible = "dynaimage,al3320a", },246 {},247};248MODULE_DEVICE_TABLE(of, al3320a_of_match);249 250static const struct acpi_device_id al3320a_acpi_match[] = {251 {"CALS0001"},252 { },253};254MODULE_DEVICE_TABLE(acpi, al3320a_acpi_match);255 256static struct i2c_driver al3320a_driver = {257 .driver = {258 .name = AL3320A_DRV_NAME,259 .of_match_table = al3320a_of_match,260 .pm = pm_sleep_ptr(&al3320a_pm_ops),261 .acpi_match_table = al3320a_acpi_match,262 },263 .probe = al3320a_probe,264 .id_table = al3320a_id,265};266 267module_i2c_driver(al3320a_driver);268 269MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");270MODULE_DESCRIPTION("AL3320A Ambient Light Sensor driver");271MODULE_LICENSE("GPL v2");272