![Linus Walleij](/assets/img/avatar_default.png)
This is a reimplementation of the old misc device driver for the ROHM BH1780 ambient light sensor (drivers/misc/bh1780gli.c). Differences from the old driver: - Uses the IIO framework - Uses runtime PM to idle the hardware after 5 seconds - No weird custom power management from userspace - No homebrewn values in sysfs This uses the same (undocumented) device tree compatible-string as the old driver ("rohm,bh1780gli"). Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Daniel Mack <daniel@caiaq.de> Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
298 lines
7.1 KiB
C
298 lines
7.1 KiB
C
/*
|
|
* 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>");
|