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/*
* ROHM 1780GLI Ambient Light Sensor Driver
*
* Copyright (C) 2016 Linaro Ltd.
* Author: Linus Walleij <linus.walleij@linaro.org>
* Loosely based on the previous BH1780 ALS misc driver
* Copyright (C) 2010 Texas Instruments
* Author: Hemanth V <hemanthv@ti.com>
*/
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/bitops.h>
#define BH1780_CMD_BIT BIT(7)
#define BH1780_REG_CONTROL 0x00
#define BH1780_REG_PARTID 0x0A
#define BH1780_REG_MANFID 0x0B
#define BH1780_REG_DLOW 0x0C
#define BH1780_REG_DHIGH 0x0D
#define BH1780_REVMASK GENMASK(3,0)
#define BH1780_POWMASK GENMASK(1,0)
#define BH1780_POFF (0x0)
#define BH1780_PON (0x3)
/* power on settling time in ms */
#define BH1780_PON_DELAY 2
/* max time before value available in ms */
#define BH1780_INTERVAL 250
struct bh1780_data {
struct i2c_client *client;
};
static int bh1780_write(struct bh1780_data *bh1780, u8 reg, u8 val)
{
int ret = i2c_smbus_write_byte_data(bh1780->client,
BH1780_CMD_BIT | reg,
val);
if (ret < 0)
dev_err(&bh1780->client->dev,
"i2c_smbus_write_byte_data failed error "
"%d, register %01x\n",
ret, reg);
return ret;
}
static int bh1780_read(struct bh1780_data *bh1780, u8 reg)
{
int ret = i2c_smbus_read_byte_data(bh1780->client,
BH1780_CMD_BIT | reg);
if (ret < 0)
dev_err(&bh1780->client->dev,
"i2c_smbus_read_byte_data failed error "
"%d, register %01x\n",
ret, reg);
return ret;
}
static int bh1780_read_word(struct bh1780_data *bh1780, u8 reg)
{
int ret = i2c_smbus_read_word_data(bh1780->client,
BH1780_CMD_BIT | reg);
if (ret < 0)
dev_err(&bh1780->client->dev,
"i2c_smbus_read_word_data failed error "
"%d, register %01x\n",
ret, reg);
return ret;
}
static int bh1780_debugfs_reg_access(struct iio_dev *indio_dev,
unsigned int reg, unsigned int writeval,
unsigned int *readval)
{
struct bh1780_data *bh1780 = iio_priv(indio_dev);
int ret;
if (!readval)
bh1780_write(bh1780, (u8)reg, (u8)writeval);
ret = bh1780_read(bh1780, (u8)reg);
if (ret < 0)
return ret;
*readval = ret;
return 0;
}
static int bh1780_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct bh1780_data *bh1780 = iio_priv(indio_dev);
int value;
switch (mask) {
case IIO_CHAN_INFO_RAW:
switch (chan->type) {
case IIO_LIGHT:
pm_runtime_get_sync(&bh1780->client->dev);
value = bh1780_read_word(bh1780, BH1780_REG_DLOW);
if (value < 0)
return value;
pm_runtime_mark_last_busy(&bh1780->client->dev);
pm_runtime_put_autosuspend(&bh1780->client->dev);
*val = value;
return IIO_VAL_INT;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_INT_TIME:
*val = 0;
*val2 = BH1780_INTERVAL * 1000;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
static const struct iio_info bh1780_info = {
.driver_module = THIS_MODULE,
.read_raw = bh1780_read_raw,
.debugfs_reg_access = bh1780_debugfs_reg_access,
};
static const struct iio_chan_spec bh1780_channels[] = {
{
.type = IIO_LIGHT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_INT_TIME)
}
};
static int bh1780_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct bh1780_data *bh1780;
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
struct iio_dev *indio_dev;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
return -EIO;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*bh1780));
if (!indio_dev)
return -ENOMEM;
bh1780 = iio_priv(indio_dev);
bh1780->client = client;
i2c_set_clientdata(client, indio_dev);
/* Power up the device */
ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON);
if (ret < 0)
return ret;
msleep(BH1780_PON_DELAY);
pm_runtime_get_noresume(&client->dev);
pm_runtime_set_active(&client->dev);
pm_runtime_enable(&client->dev);
ret = bh1780_read(bh1780, BH1780_REG_PARTID);
if (ret < 0)
goto out_disable_pm;
dev_info(&client->dev,
"Ambient Light Sensor, Rev : %lu\n",
(ret & BH1780_REVMASK));
/*
* As the device takes 250 ms to even come up with a fresh
* measurement after power-on, do not shut it down unnecessarily.
* Set autosuspend to a five seconds.
*/
pm_runtime_set_autosuspend_delay(&client->dev, 5000);
pm_runtime_use_autosuspend(&client->dev);
pm_runtime_put(&client->dev);
indio_dev->dev.parent = &client->dev;
indio_dev->info = &bh1780_info;
indio_dev->name = id->name;
indio_dev->channels = bh1780_channels;
indio_dev->num_channels = ARRAY_SIZE(bh1780_channels);
indio_dev->modes = INDIO_DIRECT_MODE;
ret = iio_device_register(indio_dev);
if (ret)
goto out_disable_pm;
return 0;
out_disable_pm:
pm_runtime_put_noidle(&client->dev);
pm_runtime_disable(&client->dev);
return ret;
}
static int bh1780_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct bh1780_data *bh1780 = iio_priv(indio_dev);
int ret;
iio_device_unregister(indio_dev);
pm_runtime_get_sync(&client->dev);
pm_runtime_put_noidle(&client->dev);
pm_runtime_disable(&client->dev);
ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF);
if (ret < 0) {
dev_err(&client->dev, "failed to power off\n");
return ret;
}
return 0;
}
#ifdef CONFIG_PM
static int bh1780_runtime_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct bh1780_data *bh1780 = i2c_get_clientdata(client);
int ret;
ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF);
if (ret < 0) {
dev_err(dev, "failed to runtime suspend\n");
return ret;
}
return 0;
}
static int bh1780_runtime_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct bh1780_data *bh1780 = i2c_get_clientdata(client);
int ret;
ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON);
if (ret < 0) {
dev_err(dev, "failed to runtime resume\n");
return ret;
}
/* Wait for power on, then for a value to be available */
msleep(BH1780_PON_DELAY + BH1780_INTERVAL);
return 0;
}
#endif /* CONFIG_PM */
static const struct dev_pm_ops bh1780_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(bh1780_runtime_suspend,
bh1780_runtime_resume, NULL)
};
static const struct i2c_device_id bh1780_id[] = {
{ "bh1780", 0 },
{ },
};
MODULE_DEVICE_TABLE(i2c, bh1780_id);
#ifdef CONFIG_OF
static const struct of_device_id of_bh1780_match[] = {
{ .compatible = "rohm,bh1780gli", },
{},
};
MODULE_DEVICE_TABLE(of, of_bh1780_match);
#endif
static struct i2c_driver bh1780_driver = {
.probe = bh1780_probe,
.remove = bh1780_remove,
.id_table = bh1780_id,
.driver = {
.name = "bh1780",
.pm = &bh1780_dev_pm_ops,
.of_match_table = of_match_ptr(of_bh1780_match),
},
};
module_i2c_driver(bh1780_driver);
MODULE_DESCRIPTION("ROHM BH1780GLI Ambient Light Sensor Driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
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