/*
* isl29003.c - Linux kernel module for
* Intersil ISL29003 ambient light sensor
*
* See file:Documentation/misc-devices/isl29003
*
* Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
*
* Based on code written by
* Rodolfo Giometti <giometti@linux.it>
* Eurotech S.p.A. <info@eurotech.it>
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#define ISL29003_DRV_NAME "isl29003"
#define DRIVER_VERSION "1.0"
#define ISL29003_REG_COMMAND 0x00
#define ISL29003_ADC_ENABLED (1 << 7)
#define ISL29003_ADC_PD (1 << 6)
#define ISL29003_TIMING_INT (1 << 5)
#define ISL29003_MODE_SHIFT (2)
#define ISL29003_MODE_MASK (0x3 << ISL29003_MODE_SHIFT)
#define ISL29003_RES_SHIFT (0)
#define ISL29003_RES_MASK (0x3 << ISL29003_RES_SHIFT)
#define ISL29003_REG_CONTROL 0x01
#define ISL29003_INT_FLG (1 << 5)
#define ISL29003_RANGE_SHIFT (2)
#define ISL29003_RANGE_MASK (0x3 << ISL29003_RANGE_SHIFT)
#define ISL29003_INT_PERSISTS_SHIFT (0)
#define ISL29003_INT_PERSISTS_MASK (0xf << ISL29003_INT_PERSISTS_SHIFT)
#define ISL29003_REG_IRQ_THRESH_HI 0x02
#define ISL29003_REG_IRQ_THRESH_LO 0x03
#define ISL29003_REG_LSB_SENSOR 0x04
#define ISL29003_REG_MSB_SENSOR 0x05
#define ISL29003_REG_LSB_TIMER 0x06
#define ISL29003_REG_MSB_TIMER 0x07
#define ISL29003_NUM_CACHABLE_REGS 4
struct isl29003_data {
struct i2c_client *client;
struct mutex lock;
u8 reg_cache[ISL29003_NUM_CACHABLE_REGS];
u8 power_state_before_suspend;
};
static int gain_range[] = {
1000, 4000, 16000, 64000
};
/*
* register access helpers
*/
static int __isl29003_read_reg(struct i2c_client *client,
u32 reg, u8 mask, u8 shift)
{
struct isl29003_data *data = i2c_get_clientdata(client);
return (data->reg_cache[reg] & mask) >> shift;
}
static int __isl29003_write_reg(struct i2c_client *client,
u32 reg, u8 mask, u8 shift, u8 val)
{
struct isl29003_data *data = i2c_get_clientdata(client);
int ret = 0;
u8 tmp;
if (reg >= ISL29003_NUM_CACHABLE_REGS)
return -EINVAL;
mutex_lock(&data->lock);
tmp = data->reg_cache[reg];
tmp &= ~mask;
tmp |= val << shift;
ret = i2c_smbus_write_byte_data(client, reg, tmp);
if (!ret)
data->reg_cache[reg] = tmp;
mutex_unlock(&data->lock);
return ret;
}
/*
* internally used functions
*/
/* range */
static int isl29003_get_range(struct i2c_client *client)
{
return __isl29003_read_reg(client, ISL29003_REG_CONTROL,
ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT);
}
static int isl29003_set_range(struct i2c_client *client, int range)
{
return __isl29003_write_reg(client, ISL29003_REG_CONTROL,
ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT, range);
}
/* resolution */
static int isl29003_get_resolution(struct i2c_client *client)
{
return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
ISL29003_RES_MASK, ISL29003_RES_SHIFT);
}
static int isl29003_set_resolution(struct i2c_client *client, int res)
{
return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
ISL29003_RES_MASK, ISL29003_RES_SHIFT, res);
}
/* mode */
static int isl29003_get_mode(struct i2c_client *client)
{
return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
ISL29003_RES_MASK, ISL29003_RES_SHIFT);
}
static int isl29003_set_mode(struct i2c_client *client, int mode)
{
return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
ISL29003_RES_MASK, ISL29003_RES_SHIFT, mode);
}
/* power_state */
static int isl29003_set_power_state(struct i2c_client *client, int state)
{
return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
ISL29003_ADC_ENABLED | ISL29003_ADC_PD, 0,
state ? ISL29003_ADC_ENABLED : ISL29003_ADC_PD);
}
static int isl29003_get_power_state(struct i2c_client *client)
{
struct isl29003_data *data = i2c_get_clientdata(client);
u8 cmdreg = data->reg_cache[ISL29003_REG_COMMAND];
return ~cmdreg & ISL29003_ADC_PD;
}
static int isl29003_get_adc_value(struct i2c_client *client)
{
struct isl29003_data *data = i2c_get_clientdata(client);
int lsb, msb, range, bitdepth;
mutex_lock(&data->lock);
lsb = i2c_smbus_read_byte_data(client, ISL29003_REG_LSB_SENSOR);
if (lsb < 0) {
mutex_unlock(&data->lock);
return lsb;
}
msb = i2c_smbus_read_byte_data(client, ISL29003_REG_MSB_SENSOR);
mutex_unlock(&data->lock);
if (msb < 0)
return msb;
range = isl29003_get_range(client);
bitdepth = (4 - isl29003_get_resolution(client)) * 4;
return (((msb << 8) | lsb) * gain_range[range]) >> bitdepth;
}
/*
* sysfs layer
*/
/* range */
static ssize_t isl29003_show_range(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
return sprintf(buf, "%i\n", isl29003_get_range(client));
}
static ssize_t isl29003_store_range(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned long val;
int ret;
if ((strict_strtoul(buf, 10, &val) < 0) || (val > 3))
return -EINVAL;
ret = isl29003_set_range(client, val);
if (ret < 0)
return ret;
return count;
}
static DEVICE_ATTR(range, S_IWUSR | S_IRUGO,
isl29003_show_range, isl29003_store_range);
/* resolution */
static ssize_t isl29003_show_resolution(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
return sprintf(buf, "%d\n", isl29003_get_resolution(client));
}
static ssize_t isl29003_store_resolution(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned long val;
int ret;
if ((strict_strtoul(buf, 10, &val) < 0) || (val > 3))
return -EINVAL;
ret = isl29003_set_resolution(client, val);
if (ret < 0)
return ret;
return count;
}
static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO,
isl29003_show_resolution, isl29003_store_resolution);
/* mode */
static ssize_t isl29003_show_mode(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
return sprintf(buf, "%d\n", isl29003_get_mode(client));
}
static ssize_t isl29003_store_mode(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned long val;
int ret;
if ((strict_strtoul(buf, 10, &val) < 0) || (val > 2))
return -EINVAL;
ret = isl29003_set_mode(client, val);
if (ret < 0)
return ret;
return count;
}
static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO,
isl29003_show_mode, isl29003_store_mode);
/* power state */
static ssize_t isl29003_show_power_state(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
return sprintf(buf, "%d\n", isl29003_get_power_state(client));
}
static ssize_t isl29003_store_power_state(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned long val;
int ret;
if ((strict_strtoul(buf, 10, &val) < 0) || (val > 1))
return -EINVAL;
ret = isl29003_set_power_state(client, val);
return ret ? ret : count;
}
static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
isl29003_show_power_state, isl29003_store_power_state);
/* lux */
static ssize_t isl29003_show_lux(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
/* No LUX data if not operational */
if (!isl29003_get_power_state(client))
return -EBUSY;
return sprintf(buf, "%d\n", isl29003_get_adc_value(client));
}
static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL);
static struct attribute *isl29003_attributes[] = {
&dev_attr_range.attr,
&dev_attr_resolution.attr,
&dev_attr_mode.attr,
&dev_attr_power_state.attr,
&dev_attr_lux.attr,
NULL
};
static const struct attribute_group isl29003_attr_group = {
.attrs = isl29003_attributes,
};
static int isl29003_init_client(struct i2c_client *client)
{
struct isl29003_data *data = i2c_get_clientdata(client);
int i;
/* read all the registers once to fill the cache.
* if one of the reads fails, we consider the init failed */
for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) {
int v = i2c_smbus_read_byte_data(client, i);
if (v < 0)
return -ENODEV;
data->reg_cache[i] = v;
}
/* set defaults */
isl29003_set_range(client, 0);
isl29003_set_resolution(client, 0);
isl29003_set_mode(client, 0);
isl29003_set_power_state(client, 0);
return 0;
}
/*
* I2C layer
*/
static int isl29003_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
struct isl29003_data *data;
int err = 0;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
return -EIO;
data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->client = client;
i2c_set_clientdata(client, data);
mutex_init(&data->lock);
/* initialize the ISL29003 chip */
err = isl29003_init_client(client);
if (err)
goto exit_kfree;
/* register sysfs hooks */
err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group);
if (err)
goto exit_kfree;
dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION);
return 0;
exit_kfree:
kfree(data);
return err;
}
static int isl29003_remove(struct i2c_client *client)
{
sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group);
isl29003_set_power_state(client, 0);
kfree(i2c_get_clientdata(client));
return 0;
}
#ifdef CONFIG_PM
static int isl29003_suspend(struct i2c_client *client, pm_message_t mesg)
{
struct isl29003_data *data = i2c_get_clientdata(client);
data->power_state_before_suspend = isl29003_get_power_state(client);
return isl29003_set_power_state(client, 0);
}
static int isl29003_resume(struct i2c_client *client)
{
int i;
struct isl29003_data *data = i2c_get_clientdata(client);
/* restore registers from cache */
for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++)
if (i2c_smbus_write_byte_data(client, i, data->reg_cache[i]))
return -EIO;
return isl29003_set_power_state(client,
data->power_state_before_suspend);
}
#else
#define isl29003_suspend NULL
#define isl29003_resume NULL
#endif /* CONFIG_PM */
static const struct i2c_device_id isl29003_id[] = {
{ "isl29003", 0 },
{}
};
MODULE_DEVICE_TABLE(i2c, isl29003_id);
static struct i2c_driver isl29003_driver = {
.driver = {
.name = ISL29003_DRV_NAME,
.owner = THIS_MODULE,
},
.suspend = isl29003_suspend,
.resume = isl29003_resume,
.probe = isl29003_probe,
.remove = isl29003_remove,
.id_table = isl29003_id,
};
module_i2c_driver(isl29003_driver);
MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
MODULE_DESCRIPTION("ISL29003 ambient light sensor driver");
MODULE_LICENSE("GPL v2");
MODULE_VERSION(DRIVER_VERSION);
