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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * ROHM 1780GLI Ambient Light Sensor Driver4 *5 * Copyright (C) 2016 Linaro Ltd.6 * Author: Linus Walleij <linus.walleij@linaro.org>7 * Loosely based on the previous BH1780 ALS misc driver8 * Copyright (C) 2010 Texas Instruments9 * Author: Hemanth V <hemanthv@ti.com>10 */11#include <linux/i2c.h>12#include <linux/slab.h>13#include <linux/platform_device.h>14#include <linux/delay.h>15#include <linux/module.h>16#include <linux/mod_devicetable.h>17#include <linux/pm_runtime.h>18#include <linux/iio/iio.h>19#include <linux/iio/sysfs.h>20#include <linux/bitops.h>21 22#define BH1780_CMD_BIT BIT(7)23#define BH1780_REG_CONTROL 0x0024#define BH1780_REG_PARTID 0x0A25#define BH1780_REG_MANFID 0x0B26#define BH1780_REG_DLOW 0x0C27#define BH1780_REG_DHIGH 0x0D28 29#define BH1780_REVMASK GENMASK(3,0)30#define BH1780_POWMASK GENMASK(1,0)31#define BH1780_POFF (0x0)32#define BH1780_PON (0x3)33 34/* power on settling time in ms */35#define BH1780_PON_DELAY 236/* max time before value available in ms */37#define BH1780_INTERVAL 25038 39struct bh1780_data {40 struct i2c_client *client;41};42 43static int bh1780_write(struct bh1780_data *bh1780, u8 reg, u8 val)44{45 int ret = i2c_smbus_write_byte_data(bh1780->client,46 BH1780_CMD_BIT | reg,47 val);48 if (ret < 0)49 dev_err(&bh1780->client->dev,50 "i2c_smbus_write_byte_data failed error "51 "%d, register %01x\n",52 ret, reg);53 return ret;54}55 56static int bh1780_read(struct bh1780_data *bh1780, u8 reg)57{58 int ret = i2c_smbus_read_byte_data(bh1780->client,59 BH1780_CMD_BIT | reg);60 if (ret < 0)61 dev_err(&bh1780->client->dev,62 "i2c_smbus_read_byte_data failed error "63 "%d, register %01x\n",64 ret, reg);65 return ret;66}67 68static int bh1780_read_word(struct bh1780_data *bh1780, u8 reg)69{70 int ret = i2c_smbus_read_word_data(bh1780->client,71 BH1780_CMD_BIT | reg);72 if (ret < 0)73 dev_err(&bh1780->client->dev,74 "i2c_smbus_read_word_data failed error "75 "%d, register %01x\n",76 ret, reg);77 return ret;78}79 80static int bh1780_debugfs_reg_access(struct iio_dev *indio_dev,81 unsigned int reg, unsigned int writeval,82 unsigned int *readval)83{84 struct bh1780_data *bh1780 = iio_priv(indio_dev);85 int ret;86 87 if (!readval)88 return bh1780_write(bh1780, (u8)reg, (u8)writeval);89 90 ret = bh1780_read(bh1780, (u8)reg);91 if (ret < 0)92 return ret;93 94 *readval = ret;95 96 return 0;97}98 99static int bh1780_read_raw(struct iio_dev *indio_dev,100 struct iio_chan_spec const *chan,101 int *val, int *val2, long mask)102{103 struct bh1780_data *bh1780 = iio_priv(indio_dev);104 int value;105 106 switch (mask) {107 case IIO_CHAN_INFO_RAW:108 switch (chan->type) {109 case IIO_LIGHT:110 pm_runtime_get_sync(&bh1780->client->dev);111 value = bh1780_read_word(bh1780, BH1780_REG_DLOW);112 if (value < 0)113 return value;114 pm_runtime_mark_last_busy(&bh1780->client->dev);115 pm_runtime_put_autosuspend(&bh1780->client->dev);116 *val = value;117 118 return IIO_VAL_INT;119 default:120 return -EINVAL;121 }122 case IIO_CHAN_INFO_INT_TIME:123 *val = 0;124 *val2 = BH1780_INTERVAL * 1000;125 return IIO_VAL_INT_PLUS_MICRO;126 default:127 return -EINVAL;128 }129}130 131static const struct iio_info bh1780_info = {132 .read_raw = bh1780_read_raw,133 .debugfs_reg_access = bh1780_debugfs_reg_access,134};135 136static const struct iio_chan_spec bh1780_channels[] = {137 {138 .type = IIO_LIGHT,139 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |140 BIT(IIO_CHAN_INFO_INT_TIME)141 }142};143 144static int bh1780_probe(struct i2c_client *client)145{146 int ret;147 struct bh1780_data *bh1780;148 struct i2c_adapter *adapter = client->adapter;149 struct iio_dev *indio_dev;150 151 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))152 return -EIO;153 154 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*bh1780));155 if (!indio_dev)156 return -ENOMEM;157 158 bh1780 = iio_priv(indio_dev);159 bh1780->client = client;160 i2c_set_clientdata(client, indio_dev);161 162 /* Power up the device */163 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON);164 if (ret < 0)165 return ret;166 msleep(BH1780_PON_DELAY);167 pm_runtime_get_noresume(&client->dev);168 pm_runtime_set_active(&client->dev);169 pm_runtime_enable(&client->dev);170 171 ret = bh1780_read(bh1780, BH1780_REG_PARTID);172 if (ret < 0)173 goto out_disable_pm;174 dev_info(&client->dev,175 "Ambient Light Sensor, Rev : %lu\n",176 (ret & BH1780_REVMASK));177 178 /*179 * As the device takes 250 ms to even come up with a fresh180 * measurement after power-on, do not shut it down unnecessarily.181 * Set autosuspend to a five seconds.182 */183 pm_runtime_set_autosuspend_delay(&client->dev, 5000);184 pm_runtime_use_autosuspend(&client->dev);185 pm_runtime_put(&client->dev);186 187 indio_dev->info = &bh1780_info;188 indio_dev->name = "bh1780";189 indio_dev->channels = bh1780_channels;190 indio_dev->num_channels = ARRAY_SIZE(bh1780_channels);191 indio_dev->modes = INDIO_DIRECT_MODE;192 193 ret = iio_device_register(indio_dev);194 if (ret)195 goto out_disable_pm;196 return 0;197 198out_disable_pm:199 pm_runtime_put_noidle(&client->dev);200 pm_runtime_disable(&client->dev);201 return ret;202}203 204static void bh1780_remove(struct i2c_client *client)205{206 struct iio_dev *indio_dev = i2c_get_clientdata(client);207 struct bh1780_data *bh1780 = iio_priv(indio_dev);208 int ret;209 210 iio_device_unregister(indio_dev);211 pm_runtime_get_sync(&client->dev);212 pm_runtime_put_noidle(&client->dev);213 pm_runtime_disable(&client->dev);214 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF);215 if (ret < 0)216 dev_err(&client->dev, "failed to power off (%pe)\n",217 ERR_PTR(ret));218}219 220static int bh1780_runtime_suspend(struct device *dev)221{222 struct i2c_client *client = to_i2c_client(dev);223 struct iio_dev *indio_dev = i2c_get_clientdata(client);224 struct bh1780_data *bh1780 = iio_priv(indio_dev);225 int ret;226 227 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF);228 if (ret < 0) {229 dev_err(dev, "failed to runtime suspend\n");230 return ret;231 }232 233 return 0;234}235 236static int bh1780_runtime_resume(struct device *dev)237{238 struct i2c_client *client = to_i2c_client(dev);239 struct iio_dev *indio_dev = i2c_get_clientdata(client);240 struct bh1780_data *bh1780 = iio_priv(indio_dev);241 int ret;242 243 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON);244 if (ret < 0) {245 dev_err(dev, "failed to runtime resume\n");246 return ret;247 }248 249 /* Wait for power on, then for a value to be available */250 msleep(BH1780_PON_DELAY + BH1780_INTERVAL);251 252 return 0;253}254 255static DEFINE_RUNTIME_DEV_PM_OPS(bh1780_dev_pm_ops, bh1780_runtime_suspend,256 bh1780_runtime_resume, NULL);257 258static const struct i2c_device_id bh1780_id[] = {259 { "bh1780" },260 { }261};262 263MODULE_DEVICE_TABLE(i2c, bh1780_id);264 265static const struct of_device_id of_bh1780_match[] = {266 { .compatible = "rohm,bh1780gli", },267 {},268};269MODULE_DEVICE_TABLE(of, of_bh1780_match);270 271static struct i2c_driver bh1780_driver = {272 .probe = bh1780_probe,273 .remove = bh1780_remove,274 .id_table = bh1780_id,275 .driver = {276 .name = "bh1780",277 .pm = pm_ptr(&bh1780_dev_pm_ops),278 .of_match_table = of_bh1780_match,279 },280};281 282module_i2c_driver(bh1780_driver);283 284MODULE_DESCRIPTION("ROHM BH1780GLI Ambient Light Sensor Driver");285MODULE_LICENSE("GPL");286MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");287