diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/chips/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/i2c/chips/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/chips/tsl2550.c | 454 |
3 files changed, 465 insertions, 0 deletions
diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig index 09fbc598d14..3944e889cb2 100644 --- a/drivers/i2c/chips/Kconfig +++ b/drivers/i2c/chips/Kconfig @@ -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 diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile index cc54a4d36cc..d8cbeb3f4b6 100644 --- a/drivers/i2c/chips/Makefile +++ b/drivers/i2c/chips/Makefile @@ -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 diff --git a/drivers/i2c/chips/tsl2550.c b/drivers/i2c/chips/tsl2550.c new file mode 100644 index 00000000000..ef80330b855 --- /dev/null +++ b/drivers/i2c/chips/tsl2550.c @@ -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); |