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linux/drivers/misc/apds9802als.c

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/*
* apds9802als.c - apds9802 ALS Driver
*
* Copyright (C) 2009 Intel Corp
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/pm_runtime.h>
#define ALS_MIN_RANGE_VAL 1
#define ALS_MAX_RANGE_VAL 2
#define POWER_STA_ENABLE 1
#define POWER_STA_DISABLE 0
#define DRIVER_NAME "apds9802als"
struct als_data {
struct mutex mutex;
};
static ssize_t als_sensing_range_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
int val;
val = i2c_smbus_read_byte_data(client, 0x81);
if (val < 0)
return val;
if (val & 1)
return sprintf(buf, "4095\n");
else
return sprintf(buf, "65535\n");
}
static int als_wait_for_data_ready(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
int ret;
int retry = 10;
do {
msleep(30);
ret = i2c_smbus_read_byte_data(client, 0x86);
} while (!(ret & 0x80) && retry--);
if (!retry) {
dev_warn(dev, "timeout waiting for data ready\n");
return -ETIMEDOUT;
}
return 0;
}
static ssize_t als_lux0_input_data_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
struct als_data *data = i2c_get_clientdata(client);
int ret_val;
int temp;
/* Protect against parallel reads */
pm_runtime_get_sync(dev);
mutex_lock(&data->mutex);
/* clear EOC interrupt status */
i2c_smbus_write_byte(client, 0x40);
/* start measurement */
temp = i2c_smbus_read_byte_data(client, 0x81);
i2c_smbus_write_byte_data(client, 0x81, temp | 0x08);
ret_val = als_wait_for_data_ready(dev);
if (ret_val < 0)
goto failed;
temp = i2c_smbus_read_byte_data(client, 0x8C); /* LSB data */
if (temp < 0) {
ret_val = temp;
goto failed;
}
ret_val = i2c_smbus_read_byte_data(client, 0x8D); /* MSB data */
if (ret_val < 0)
goto failed;
mutex_unlock(&data->mutex);
pm_runtime_put_sync(dev);
temp = (ret_val << 8) | temp;
return sprintf(buf, "%d\n", temp);
failed:
mutex_unlock(&data->mutex);
pm_runtime_put_sync(dev);
return ret_val;
}
static ssize_t als_sensing_range_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct als_data *data = i2c_get_clientdata(client);
int ret_val;
unsigned long val;
if (strict_strtoul(buf, 10, &val))
return -EINVAL;
if (val < 4096)
val = 1;
else if (val < 65536)
val = 2;
else
return -ERANGE;
pm_runtime_get_sync(dev);
/* Make sure nobody else reads/modifies/writes 0x81 while we
are active */
mutex_lock(&data->mutex);
ret_val = i2c_smbus_read_byte_data(client, 0x81);
if (ret_val < 0)
goto fail;
/* Reset the bits before setting them */
ret_val = ret_val & 0xFA;
if (val == 1) /* Setting detection range up to 4k LUX */
ret_val = (ret_val | 0x01);
else /* Setting detection range up to 64k LUX*/
ret_val = (ret_val | 0x00);
ret_val = i2c_smbus_write_byte_data(client, 0x81, ret_val);
if (ret_val >= 0) {
/* All OK */
mutex_unlock(&data->mutex);
pm_runtime_put_sync(dev);
return count;
}
fail:
mutex_unlock(&data->mutex);
pm_runtime_put_sync(dev);
return ret_val;
}
static int als_set_power_state(struct i2c_client *client, bool on_off)
{
int ret_val;
struct als_data *data = i2c_get_clientdata(client);
mutex_lock(&data->mutex);
ret_val = i2c_smbus_read_byte_data(client, 0x80);
if (ret_val < 0)
goto fail;
if (on_off)
ret_val = ret_val | 0x01;
else
ret_val = ret_val & 0xFE;
ret_val = i2c_smbus_write_byte_data(client, 0x80, ret_val);
fail:
mutex_unlock(&data->mutex);
return ret_val;
}
static DEVICE_ATTR(lux0_sensor_range, S_IRUGO | S_IWUSR,
als_sensing_range_show, als_sensing_range_store);
static DEVICE_ATTR(lux0_input, S_IRUGO, als_lux0_input_data_show, NULL);
static struct attribute *mid_att_als[] = {
&dev_attr_lux0_sensor_range.attr,
&dev_attr_lux0_input.attr,
NULL
};
static struct attribute_group m_als_gr = {
.name = "apds9802als",
.attrs = mid_att_als
};
static int als_set_default_config(struct i2c_client *client)
{
int ret_val;
/* Write the command and then switch on */
ret_val = i2c_smbus_write_byte_data(client, 0x80, 0x01);
if (ret_val < 0) {
dev_err(&client->dev, "failed default switch on write\n");
return ret_val;
}
/* detection range: 1~64K Lux, maunal measurement */
ret_val = i2c_smbus_write_byte_data(client, 0x81, 0x08);
if (ret_val < 0)
dev_err(&client->dev, "failed default LUX on write\n");
/* We always get 0 for the 1st measurement after system power on,
* so make sure it is finished before user asks for data.
*/
als_wait_for_data_ready(&client->dev);
return ret_val;
}
static int apds9802als_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int res;
struct als_data *data;
data = kzalloc(sizeof(struct als_data), GFP_KERNEL);
if (data == NULL) {
dev_err(&client->dev, "Memory allocation failed\n");
return -ENOMEM;
}
i2c_set_clientdata(client, data);
res = sysfs_create_group(&client->dev.kobj, &m_als_gr);
if (res) {
dev_err(&client->dev, "device create file failed\n");
goto als_error1;
}
dev_info(&client->dev, "ALS chip found\n");
als_set_default_config(client);
mutex_init(&data->mutex);
pm_runtime_set_active(&client->dev);
pm_runtime_enable(&client->dev);
return res;
als_error1:
kfree(data);
return res;
}
static int __devexit apds9802als_remove(struct i2c_client *client)
{
struct als_data *data = i2c_get_clientdata(client);
pm_runtime_get_sync(&client->dev);
als_set_power_state(client, false);
sysfs_remove_group(&client->dev.kobj, &m_als_gr);
pm_runtime_disable(&client->dev);
pm_runtime_set_suspended(&client->dev);
pm_runtime_put_noidle(&client->dev);
kfree(data);
return 0;
}
#ifdef CONFIG_PM
static int apds9802als_suspend(struct i2c_client *client, pm_message_t mesg)
{
als_set_power_state(client, false);
return 0;
}
static int apds9802als_resume(struct i2c_client *client)
{
als_set_default_config(client);
return 0;
}
static int apds9802als_runtime_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
als_set_power_state(client, false);
return 0;
}
static int apds9802als_runtime_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
als_set_power_state(client, true);
return 0;
}
static const struct dev_pm_ops apds9802als_pm_ops = {
.runtime_suspend = apds9802als_runtime_suspend,
.runtime_resume = apds9802als_runtime_resume,
};
#define APDS9802ALS_PM_OPS (&apds9802als_pm_ops)
#else /* CONFIG_PM */
#define apds9802als_suspend NULL
#define apds9802als_resume NULL
#define APDS9802ALS_PM_OPS NULL
#endif /* CONFIG_PM */
static struct i2c_device_id apds9802als_id[] = {
{ DRIVER_NAME, 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, apds9802als_id);
static struct i2c_driver apds9802als_driver = {
.driver = {
.name = DRIVER_NAME,
.pm = APDS9802ALS_PM_OPS,
},
.probe = apds9802als_probe,
.remove = __devexit_p(apds9802als_remove),
.suspend = apds9802als_suspend,
.resume = apds9802als_resume,
.id_table = apds9802als_id,
};
module_i2c_driver(apds9802als_driver);
MODULE_AUTHOR("Anantha Narayanan <Anantha.Narayanan@intel.com");
MODULE_DESCRIPTION("Avago apds9802als ALS Driver");
MODULE_LICENSE("GPL v2");
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