diff options
Diffstat (limited to 'drivers/iio/light/bh1780.c')
| -rw-r--r-- | drivers/iio/light/bh1780.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/iio/light/bh1780.c b/drivers/iio/light/bh1780.c new file mode 100644 index 000000000..90bca392b --- /dev/null +++ b/drivers/iio/light/bh1780.c @@ -0,0 +1,287 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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/mod_devicetable.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) + return 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 = { + .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 = client->adapter; + 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->info = &bh1780_info; + indio_dev->name = "bh1780"; + 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 void 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 (%pe)\n", + ERR_PTR(ret)); +} + +static int bh1780_runtime_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct bh1780_data *bh1780 = iio_priv(indio_dev); + 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 iio_dev *indio_dev = i2c_get_clientdata(client); + struct bh1780_data *bh1780 = iio_priv(indio_dev); + 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; +} + +static DEFINE_RUNTIME_DEV_PM_OPS(bh1780_dev_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); + +static const struct of_device_id of_bh1780_match[] = { + { .compatible = "rohm,bh1780gli", }, + {}, +}; +MODULE_DEVICE_TABLE(of, of_bh1780_match); + +static struct i2c_driver bh1780_driver = { + .probe = bh1780_probe, + .remove = bh1780_remove, + .id_table = bh1780_id, + .driver = { + .name = "bh1780", + .pm = pm_ptr(&bh1780_dev_pm_ops), + .of_match_table = 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>"); |