275 строки
6.2 KiB
C
275 строки
6.2 KiB
C
/*
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* bh1780gli.c
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* ROHM Ambient Light Sensor Driver
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*
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* Copyright (C) 2010 Texas Instruments
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* Author: Hemanth V <hemanthv@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/i2c.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
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#include <linux/platform_device.h>
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#include <linux/delay.h>
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#include <linux/module.h>
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#define BH1780_REG_CONTROL 0x80
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#define BH1780_REG_PARTID 0x8A
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#define BH1780_REG_MANFID 0x8B
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#define BH1780_REG_DLOW 0x8C
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#define BH1780_REG_DHIGH 0x8D
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#define BH1780_REVMASK (0xf)
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#define BH1780_POWMASK (0x3)
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#define BH1780_POFF (0x0)
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#define BH1780_PON (0x3)
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/* power on settling time in ms */
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#define BH1780_PON_DELAY 2
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struct bh1780_data {
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struct i2c_client *client;
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int power_state;
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/* lock for sysfs operations */
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struct mutex lock;
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};
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static int bh1780_write(struct bh1780_data *ddata, u8 reg, u8 val, char *msg)
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{
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int ret = i2c_smbus_write_byte_data(ddata->client, reg, val);
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if (ret < 0)
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dev_err(&ddata->client->dev,
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"i2c_smbus_write_byte_data failed error %d Register (%s)\n",
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ret, msg);
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return ret;
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}
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static int bh1780_read(struct bh1780_data *ddata, u8 reg, char *msg)
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{
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int ret = i2c_smbus_read_byte_data(ddata->client, reg);
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if (ret < 0)
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dev_err(&ddata->client->dev,
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"i2c_smbus_read_byte_data failed error %d Register (%s)\n",
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ret, msg);
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return ret;
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}
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static ssize_t bh1780_show_lux(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct bh1780_data *ddata = platform_get_drvdata(pdev);
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int lsb, msb;
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lsb = bh1780_read(ddata, BH1780_REG_DLOW, "DLOW");
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if (lsb < 0)
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return lsb;
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msb = bh1780_read(ddata, BH1780_REG_DHIGH, "DHIGH");
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if (msb < 0)
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return msb;
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return sprintf(buf, "%d\n", (msb << 8) | lsb);
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}
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static ssize_t bh1780_show_power_state(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct bh1780_data *ddata = platform_get_drvdata(pdev);
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int state;
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state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
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if (state < 0)
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return state;
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return sprintf(buf, "%d\n", state & BH1780_POWMASK);
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}
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static ssize_t bh1780_store_power_state(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct bh1780_data *ddata = platform_get_drvdata(pdev);
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unsigned long val;
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int error;
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error = strict_strtoul(buf, 0, &val);
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if (error)
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return error;
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if (val < BH1780_POFF || val > BH1780_PON)
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return -EINVAL;
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mutex_lock(&ddata->lock);
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error = bh1780_write(ddata, BH1780_REG_CONTROL, val, "CONTROL");
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if (error < 0) {
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mutex_unlock(&ddata->lock);
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return error;
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}
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msleep(BH1780_PON_DELAY);
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ddata->power_state = val;
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mutex_unlock(&ddata->lock);
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return count;
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}
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static DEVICE_ATTR(lux, S_IRUGO, bh1780_show_lux, NULL);
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static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
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bh1780_show_power_state, bh1780_store_power_state);
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static struct attribute *bh1780_attributes[] = {
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&dev_attr_power_state.attr,
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&dev_attr_lux.attr,
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NULL
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};
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static const struct attribute_group bh1780_attr_group = {
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.attrs = bh1780_attributes,
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};
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static int __devinit bh1780_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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int ret;
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struct bh1780_data *ddata = NULL;
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struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) {
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ret = -EIO;
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goto err_op_failed;
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}
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ddata = kzalloc(sizeof(struct bh1780_data), GFP_KERNEL);
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if (ddata == NULL) {
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ret = -ENOMEM;
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goto err_op_failed;
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}
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ddata->client = client;
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i2c_set_clientdata(client, ddata);
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ret = bh1780_read(ddata, BH1780_REG_PARTID, "PART ID");
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if (ret < 0)
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goto err_op_failed;
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dev_info(&client->dev, "Ambient Light Sensor, Rev : %d\n",
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(ret & BH1780_REVMASK));
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mutex_init(&ddata->lock);
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ret = sysfs_create_group(&client->dev.kobj, &bh1780_attr_group);
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if (ret)
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goto err_op_failed;
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return 0;
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err_op_failed:
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kfree(ddata);
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return ret;
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}
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static int __devexit bh1780_remove(struct i2c_client *client)
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{
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struct bh1780_data *ddata;
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ddata = i2c_get_clientdata(client);
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sysfs_remove_group(&client->dev.kobj, &bh1780_attr_group);
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kfree(ddata);
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return 0;
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}
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#ifdef CONFIG_PM
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static int bh1780_suspend(struct device *dev)
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{
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struct bh1780_data *ddata;
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int state, ret;
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struct i2c_client *client = to_i2c_client(dev);
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ddata = i2c_get_clientdata(client);
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state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
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if (state < 0)
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return state;
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ddata->power_state = state & BH1780_POWMASK;
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ret = bh1780_write(ddata, BH1780_REG_CONTROL, BH1780_POFF,
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"CONTROL");
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if (ret < 0)
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return ret;
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return 0;
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}
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static int bh1780_resume(struct device *dev)
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{
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struct bh1780_data *ddata;
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int state, ret;
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struct i2c_client *client = to_i2c_client(dev);
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ddata = i2c_get_clientdata(client);
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state = ddata->power_state;
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ret = bh1780_write(ddata, BH1780_REG_CONTROL, state,
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"CONTROL");
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if (ret < 0)
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return ret;
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(bh1780_pm, bh1780_suspend, bh1780_resume);
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#define BH1780_PMOPS (&bh1780_pm)
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#else
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#define BH1780_PMOPS NULL
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#endif /* CONFIG_PM */
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static const struct i2c_device_id bh1780_id[] = {
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{ "bh1780", 0 },
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{ },
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};
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static struct i2c_driver bh1780_driver = {
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.probe = bh1780_probe,
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.remove = bh1780_remove,
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.id_table = bh1780_id,
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.driver = {
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.name = "bh1780",
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.pm = BH1780_PMOPS,
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},
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};
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static int __init bh1780_init(void)
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{
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return i2c_add_driver(&bh1780_driver);
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}
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static void __exit bh1780_exit(void)
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{
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i2c_del_driver(&bh1780_driver);
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}
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module_init(bh1780_init)
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module_exit(bh1780_exit)
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MODULE_DESCRIPTION("BH1780GLI Ambient Light Sensor Driver");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");
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