i2c: Add support for the TSL2550
Add support for Taos TSL2550 ambient light sensors. (http://www.taosinc.com/product_detail.asp?cateid=4&proid=18). Signed-off-by: Rodolfo Giometti <giometti@linux.it> Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
Rodolfo Giometti
Jean Delvare
parent
066af983c7
commit
a92c344d8c
|
|
@ -143,4 +143,14 @@ config SENSORS_MAX6875
|
|||
This driver can also be built as a module. If so, the module
|
||||
will be called max6875.
|
||||
|
||||
config SENSORS_TSL2550
|
||||
tristate "Taos TSL2550 ambient light sensor"
|
||||
depends on EXPERIMENTAL
|
||||
help
|
||||
If you say yes here you get support for the Taos TSL2550
|
||||
ambient light sensor.
|
||||
|
||||
This driver can also be built as a module. If so, the module
|
||||
will be called tsl2550.
|
||||
|
||||
endmenu
|
||||
|
|
|
|||
|
|
@ -13,6 +13,7 @@ obj-$(CONFIG_SENSORS_PCF8574) += pcf8574.o
|
|||
obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
|
||||
obj-$(CONFIG_ISP1301_OMAP) += isp1301_omap.o
|
||||
obj-$(CONFIG_TPS65010) += tps65010.o
|
||||
obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o
|
||||
|
||||
ifeq ($(CONFIG_I2C_DEBUG_CHIP),y)
|
||||
EXTRA_CFLAGS += -DDEBUG
|
||||
|
|
|
|||
|
|
@ -0,0 +1,454 @@
|
|||
/*
|
||||
* tsl2550.c - Linux kernel modules for ambient light sensor
|
||||
*
|
||||
* Copyright (C) 2007 Rodolfo Giometti <giometti@linux.it>
|
||||
* Copyright (C) 2007 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 TSL2550_DRV_NAME "tsl2550"
|
||||
#define DRIVER_VERSION "1.1.0"
|
||||
|
||||
/*
|
||||
* Defines
|
||||
*/
|
||||
|
||||
#define TSL2550_POWER_DOWN 0x00
|
||||
#define TSL2550_POWER_UP 0x03
|
||||
#define TSL2550_STANDARD_RANGE 0x18
|
||||
#define TSL2550_EXTENDED_RANGE 0x1d
|
||||
#define TSL2550_READ_ADC0 0x43
|
||||
#define TSL2550_READ_ADC1 0x83
|
||||
|
||||
/*
|
||||
* Structs
|
||||
*/
|
||||
|
||||
struct tsl2550_data {
|
||||
struct i2c_client *client;
|
||||
struct mutex update_lock;
|
||||
|
||||
unsigned int power_state : 1;
|
||||
unsigned int operating_mode : 1;
|
||||
};
|
||||
|
||||
/*
|
||||
* Global data
|
||||
*/
|
||||
|
||||
static const u8 TSL2550_MODE_RANGE[2] = {
|
||||
TSL2550_STANDARD_RANGE, TSL2550_EXTENDED_RANGE,
|
||||
};
|
||||
|
||||
/*
|
||||
* Management functions
|
||||
*/
|
||||
|
||||
static int tsl2550_set_operating_mode(struct i2c_client *client, int mode)
|
||||
{
|
||||
struct tsl2550_data *data = i2c_get_clientdata(client);
|
||||
|
||||
int ret = i2c_smbus_write_byte(client, TSL2550_MODE_RANGE[mode]);
|
||||
|
||||
data->operating_mode = mode;
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int tsl2550_set_power_state(struct i2c_client *client, int state)
|
||||
{
|
||||
struct tsl2550_data *data = i2c_get_clientdata(client);
|
||||
int ret;
|
||||
|
||||
if (state == 0)
|
||||
ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN);
|
||||
else {
|
||||
ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP);
|
||||
|
||||
/* On power up we should reset operating mode also... */
|
||||
tsl2550_set_operating_mode(client, data->operating_mode);
|
||||
}
|
||||
|
||||
data->power_state = state;
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int tsl2550_get_adc_value(struct i2c_client *client, u8 cmd)
|
||||
{
|
||||
unsigned long end;
|
||||
int loop = 0, ret = 0;
|
||||
|
||||
/*
|
||||
* Read ADC channel waiting at most 400ms (see data sheet for further
|
||||
* info).
|
||||
* To avoid long busy wait we spin for few milliseconds then
|
||||
* start sleeping.
|
||||
*/
|
||||
end = jiffies + msecs_to_jiffies(400);
|
||||
while (time_before(jiffies, end)) {
|
||||
i2c_smbus_write_byte(client, cmd);
|
||||
|
||||
if (loop++ < 5)
|
||||
mdelay(1);
|
||||
else
|
||||
msleep(1);
|
||||
|
||||
ret = i2c_smbus_read_byte(client);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
else if (ret & 0x0080)
|
||||
break;
|
||||
}
|
||||
if (!(ret & 0x80))
|
||||
return -EIO;
|
||||
return ret & 0x7f; /* remove the "valid" bit */
|
||||
}
|
||||
|
||||
/*
|
||||
* LUX calculation
|
||||
*/
|
||||
|
||||
#define TSL2550_MAX_LUX 1846
|
||||
|
||||
static const u8 ratio_lut[] = {
|
||||
100, 100, 100, 100, 100, 100, 100, 100,
|
||||
100, 100, 100, 100, 100, 100, 99, 99,
|
||||
99, 99, 99, 99, 99, 99, 99, 99,
|
||||
99, 99, 99, 98, 98, 98, 98, 98,
|
||||
98, 98, 97, 97, 97, 97, 97, 96,
|
||||
96, 96, 96, 95, 95, 95, 94, 94,
|
||||
93, 93, 93, 92, 92, 91, 91, 90,
|
||||
89, 89, 88, 87, 87, 86, 85, 84,
|
||||
83, 82, 81, 80, 79, 78, 77, 75,
|
||||
74, 73, 71, 69, 68, 66, 64, 62,
|
||||
60, 58, 56, 54, 52, 49, 47, 44,
|
||||
42, 41, 40, 40, 39, 39, 38, 38,
|
||||
37, 37, 37, 36, 36, 36, 35, 35,
|
||||
35, 35, 34, 34, 34, 34, 33, 33,
|
||||
33, 33, 32, 32, 32, 32, 32, 31,
|
||||
31, 31, 31, 31, 30, 30, 30, 30,
|
||||
30,
|
||||
};
|
||||
|
||||
static const u16 count_lut[] = {
|
||||
0, 1, 2, 3, 4, 5, 6, 7,
|
||||
8, 9, 10, 11, 12, 13, 14, 15,
|
||||
16, 18, 20, 22, 24, 26, 28, 30,
|
||||
32, 34, 36, 38, 40, 42, 44, 46,
|
||||
49, 53, 57, 61, 65, 69, 73, 77,
|
||||
81, 85, 89, 93, 97, 101, 105, 109,
|
||||
115, 123, 131, 139, 147, 155, 163, 171,
|
||||
179, 187, 195, 203, 211, 219, 227, 235,
|
||||
247, 263, 279, 295, 311, 327, 343, 359,
|
||||
375, 391, 407, 423, 439, 455, 471, 487,
|
||||
511, 543, 575, 607, 639, 671, 703, 735,
|
||||
767, 799, 831, 863, 895, 927, 959, 991,
|
||||
1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487,
|
||||
1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999,
|
||||
2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991,
|
||||
3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015,
|
||||
};
|
||||
|
||||
/*
|
||||
* This function is described into Taos TSL2550 Designer's Notebook
|
||||
* pages 2, 3.
|
||||
*/
|
||||
static int tsl2550_calculate_lux(u8 ch0, u8 ch1)
|
||||
{
|
||||
unsigned int lux;
|
||||
|
||||
/* Look up count from channel values */
|
||||
u16 c0 = count_lut[ch0];
|
||||
u16 c1 = count_lut[ch1];
|
||||
|
||||
/*
|
||||
* Calculate ratio.
|
||||
* Note: the "128" is a scaling factor
|
||||
*/
|
||||
u8 r = 128;
|
||||
|
||||
/* Avoid division by 0 and count 1 cannot be greater than count 0 */
|
||||
if (c0 && (c1 <= c0))
|
||||
r = c1 * 128 / c0;
|
||||
else
|
||||
return -1;
|
||||
|
||||
/* Calculate LUX */
|
||||
lux = ((c0 - c1) * ratio_lut[r]) / 256;
|
||||
|
||||
/* LUX range check */
|
||||
return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux;
|
||||
}
|
||||
|
||||
/*
|
||||
* SysFS support
|
||||
*/
|
||||
|
||||
static ssize_t tsl2550_show_power_state(struct device *dev,
|
||||
struct device_attribute *attr, char *buf)
|
||||
{
|
||||
struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
|
||||
|
||||
return sprintf(buf, "%u\n", data->power_state);
|
||||
}
|
||||
|
||||
static ssize_t tsl2550_store_power_state(struct device *dev,
|
||||
struct device_attribute *attr, const char *buf, size_t count)
|
||||
{
|
||||
struct i2c_client *client = to_i2c_client(dev);
|
||||
struct tsl2550_data *data = i2c_get_clientdata(client);
|
||||
unsigned long val = simple_strtoul(buf, NULL, 10);
|
||||
int ret;
|
||||
|
||||
if (val < 0 || val > 1)
|
||||
return -EINVAL;
|
||||
|
||||
mutex_lock(&data->update_lock);
|
||||
ret = tsl2550_set_power_state(client, val);
|
||||
mutex_unlock(&data->update_lock);
|
||||
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
return count;
|
||||
}
|
||||
|
||||
static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
|
||||
tsl2550_show_power_state, tsl2550_store_power_state);
|
||||
|
||||
static ssize_t tsl2550_show_operating_mode(struct device *dev,
|
||||
struct device_attribute *attr, char *buf)
|
||||
{
|
||||
struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
|
||||
|
||||
return sprintf(buf, "%u\n", data->operating_mode);
|
||||
}
|
||||
|
||||
static ssize_t tsl2550_store_operating_mode(struct device *dev,
|
||||
struct device_attribute *attr, const char *buf, size_t count)
|
||||
{
|
||||
struct i2c_client *client = to_i2c_client(dev);
|
||||
struct tsl2550_data *data = i2c_get_clientdata(client);
|
||||
unsigned long val = simple_strtoul(buf, NULL, 10);
|
||||
int ret;
|
||||
|
||||
if (val < 0 || val > 1)
|
||||
return -EINVAL;
|
||||
|
||||
if (data->power_state == 0)
|
||||
return -EBUSY;
|
||||
|
||||
mutex_lock(&data->update_lock);
|
||||
ret = tsl2550_set_operating_mode(client, val);
|
||||
mutex_unlock(&data->update_lock);
|
||||
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
return count;
|
||||
}
|
||||
|
||||
static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO,
|
||||
tsl2550_show_operating_mode, tsl2550_store_operating_mode);
|
||||
|
||||
static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf)
|
||||
{
|
||||
u8 ch0, ch1;
|
||||
int ret;
|
||||
|
||||
ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
ch0 = ret;
|
||||
|
||||
mdelay(1);
|
||||
|
||||
ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
ch1 = ret;
|
||||
|
||||
/* Do the job */
|
||||
ret = tsl2550_calculate_lux(ch0, ch1);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
return sprintf(buf, "%d\n", ret);
|
||||
}
|
||||
|
||||
static ssize_t tsl2550_show_lux1_input(struct device *dev,
|
||||
struct device_attribute *attr, char *buf)
|
||||
{
|
||||
struct i2c_client *client = to_i2c_client(dev);
|
||||
struct tsl2550_data *data = i2c_get_clientdata(client);
|
||||
int ret;
|
||||
|
||||
/* No LUX data if not operational */
|
||||
if (!data->power_state)
|
||||
return -EBUSY;
|
||||
|
||||
mutex_lock(&data->update_lock);
|
||||
ret = __tsl2550_show_lux(client, buf);
|
||||
mutex_unlock(&data->update_lock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static DEVICE_ATTR(lux1_input, S_IRUGO,
|
||||
tsl2550_show_lux1_input, NULL);
|
||||
|
||||
static struct attribute *tsl2550_attributes[] = {
|
||||
&dev_attr_power_state.attr,
|
||||
&dev_attr_operating_mode.attr,
|
||||
&dev_attr_lux1_input.attr,
|
||||
NULL
|
||||
};
|
||||
|
||||
static const struct attribute_group tsl2550_attr_group = {
|
||||
.attrs = tsl2550_attributes,
|
||||
};
|
||||
|
||||
/*
|
||||
* Initialization function
|
||||
*/
|
||||
|
||||
static void tsl2550_init_client(struct i2c_client *client)
|
||||
{
|
||||
struct tsl2550_data *data = i2c_get_clientdata(client);
|
||||
|
||||
/* Power up the device and set the default operating mode */
|
||||
tsl2550_set_power_state(client, 1);
|
||||
tsl2550_set_operating_mode(client, data->operating_mode);
|
||||
}
|
||||
|
||||
/*
|
||||
* I2C init/probing/exit functions
|
||||
*/
|
||||
|
||||
static struct i2c_driver tsl2550_driver;
|
||||
static int __devinit tsl2550_probe(struct i2c_client *client)
|
||||
{
|
||||
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
|
||||
struct tsl2550_data *data;
|
||||
int *opmode, err = 0;
|
||||
|
||||
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) {
|
||||
err = -EIO;
|
||||
goto exit;
|
||||
}
|
||||
|
||||
data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL);
|
||||
if (!data) {
|
||||
err = -ENOMEM;
|
||||
goto exit;
|
||||
}
|
||||
data->client = client;
|
||||
i2c_set_clientdata(client, data);
|
||||
|
||||
/* Check platform data */
|
||||
opmode = client->dev.platform_data;
|
||||
if (opmode) {
|
||||
if (*opmode < 0 || *opmode > 1) {
|
||||
dev_err(&client->dev, "invalid operating_mode (%d)\n",
|
||||
*opmode);
|
||||
err = -EINVAL;
|
||||
goto exit_kfree;
|
||||
}
|
||||
data->operating_mode = *opmode;
|
||||
} else
|
||||
data->operating_mode = 0; /* default mode is standard */
|
||||
dev_info(&client->dev, "%s operating mode\n",
|
||||
data->operating_mode ? "extended" : "standard");
|
||||
|
||||
/*
|
||||
* Probe the chip. To do so we try to power up the device and then to
|
||||
* read back the 0x03 code
|
||||
*/
|
||||
err = i2c_smbus_write_byte(client, TSL2550_POWER_UP);
|
||||
if (err < 0)
|
||||
goto exit_kfree;
|
||||
mdelay(1);
|
||||
err = i2c_smbus_read_byte(client);
|
||||
if (err != TSL2550_POWER_UP) {
|
||||
err = -ENODEV;
|
||||
goto exit_kfree;
|
||||
}
|
||||
|
||||
mutex_init(&data->update_lock);
|
||||
|
||||
/* Initialize the TSL2550 chip */
|
||||
tsl2550_init_client(client);
|
||||
|
||||
/* Register sysfs hooks */
|
||||
err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group);
|
||||
if (err)
|
||||
goto exit_kfree;
|
||||
|
||||
dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
|
||||
|
||||
return 0;
|
||||
|
||||
exit_kfree:
|
||||
kfree(data);
|
||||
exit:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int __devexit tsl2550_remove(struct i2c_client *client)
|
||||
{
|
||||
sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group);
|
||||
|
||||
/* Power down the device */
|
||||
tsl2550_set_power_state(client, 0);
|
||||
|
||||
kfree(i2c_get_clientdata(client));
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct i2c_driver tsl2550_driver = {
|
||||
.driver = {
|
||||
.name = TSL2550_DRV_NAME,
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
.probe = tsl2550_probe,
|
||||
.remove = __devexit_p(tsl2550_remove),
|
||||
};
|
||||
|
||||
static int __init tsl2550_init(void)
|
||||
{
|
||||
return i2c_add_driver(&tsl2550_driver);
|
||||
}
|
||||
|
||||
static void __exit tsl2550_exit(void)
|
||||
{
|
||||
i2c_del_driver(&tsl2550_driver);
|
||||
}
|
||||
|
||||
MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
|
||||
MODULE_DESCRIPTION("TSL2550 ambient light sensor driver");
|
||||
MODULE_LICENSE("GPL");
|
||||
|
||||
module_init(tsl2550_init);
|
||||
module_exit(tsl2550_exit);
|
||||
Reference in New Issue