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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
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This driver can also be built as a module. If so, the module
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will be called max6875.
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config SENSORS_TSL2550
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tristate "Taos TSL2550 ambient light sensor"
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depends on EXPERIMENTAL
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help
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If you say yes here you get support for the Taos TSL2550
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ambient light sensor.
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This driver can also be built as a module. If so, the module
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will be called tsl2550.
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endmenu
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@ -13,6 +13,7 @@ obj-$(CONFIG_SENSORS_PCF8574) += pcf8574.o
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obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
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obj-$(CONFIG_ISP1301_OMAP) += isp1301_omap.o
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obj-$(CONFIG_TPS65010) += tps65010.o
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obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o
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ifeq ($(CONFIG_I2C_DEBUG_CHIP),y)
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EXTRA_CFLAGS += -DDEBUG
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454
drivers/i2c/chips/tsl2550.c
Normal file
454
drivers/i2c/chips/tsl2550.c
Normal file
@ -0,0 +1,454 @@
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/*
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* tsl2550.c - Linux kernel modules for ambient light sensor
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*
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* Copyright (C) 2007 Rodolfo Giometti <giometti@linux.it>
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* Copyright (C) 2007 Eurotech S.p.A. <info@eurotech.it>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/mutex.h>
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#include <linux/delay.h>
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#define TSL2550_DRV_NAME "tsl2550"
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#define DRIVER_VERSION "1.1.0"
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/*
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* Defines
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*/
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#define TSL2550_POWER_DOWN 0x00
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#define TSL2550_POWER_UP 0x03
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#define TSL2550_STANDARD_RANGE 0x18
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#define TSL2550_EXTENDED_RANGE 0x1d
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#define TSL2550_READ_ADC0 0x43
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#define TSL2550_READ_ADC1 0x83
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/*
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* Structs
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*/
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struct tsl2550_data {
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struct i2c_client *client;
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struct mutex update_lock;
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unsigned int power_state : 1;
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unsigned int operating_mode : 1;
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};
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/*
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* Global data
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*/
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static const u8 TSL2550_MODE_RANGE[2] = {
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TSL2550_STANDARD_RANGE, TSL2550_EXTENDED_RANGE,
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};
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/*
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* Management functions
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*/
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static int tsl2550_set_operating_mode(struct i2c_client *client, int mode)
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{
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struct tsl2550_data *data = i2c_get_clientdata(client);
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int ret = i2c_smbus_write_byte(client, TSL2550_MODE_RANGE[mode]);
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data->operating_mode = mode;
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return ret;
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}
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static int tsl2550_set_power_state(struct i2c_client *client, int state)
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{
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struct tsl2550_data *data = i2c_get_clientdata(client);
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int ret;
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if (state == 0)
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ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN);
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else {
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ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP);
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/* On power up we should reset operating mode also... */
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tsl2550_set_operating_mode(client, data->operating_mode);
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}
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data->power_state = state;
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return ret;
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}
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static int tsl2550_get_adc_value(struct i2c_client *client, u8 cmd)
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{
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unsigned long end;
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int loop = 0, ret = 0;
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/*
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* Read ADC channel waiting at most 400ms (see data sheet for further
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* info).
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* To avoid long busy wait we spin for few milliseconds then
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* start sleeping.
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*/
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end = jiffies + msecs_to_jiffies(400);
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while (time_before(jiffies, end)) {
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i2c_smbus_write_byte(client, cmd);
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if (loop++ < 5)
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mdelay(1);
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else
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msleep(1);
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ret = i2c_smbus_read_byte(client);
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if (ret < 0)
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return ret;
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else if (ret & 0x0080)
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break;
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}
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if (!(ret & 0x80))
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return -EIO;
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return ret & 0x7f; /* remove the "valid" bit */
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}
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/*
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* LUX calculation
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*/
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#define TSL2550_MAX_LUX 1846
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static const u8 ratio_lut[] = {
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100, 100, 100, 100, 100, 100, 100, 100,
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100, 100, 100, 100, 100, 100, 99, 99,
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99, 99, 99, 99, 99, 99, 99, 99,
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99, 99, 99, 98, 98, 98, 98, 98,
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98, 98, 97, 97, 97, 97, 97, 96,
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96, 96, 96, 95, 95, 95, 94, 94,
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93, 93, 93, 92, 92, 91, 91, 90,
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89, 89, 88, 87, 87, 86, 85, 84,
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83, 82, 81, 80, 79, 78, 77, 75,
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74, 73, 71, 69, 68, 66, 64, 62,
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60, 58, 56, 54, 52, 49, 47, 44,
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42, 41, 40, 40, 39, 39, 38, 38,
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37, 37, 37, 36, 36, 36, 35, 35,
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35, 35, 34, 34, 34, 34, 33, 33,
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33, 33, 32, 32, 32, 32, 32, 31,
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31, 31, 31, 31, 30, 30, 30, 30,
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30,
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};
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static const u16 count_lut[] = {
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0, 1, 2, 3, 4, 5, 6, 7,
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8, 9, 10, 11, 12, 13, 14, 15,
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16, 18, 20, 22, 24, 26, 28, 30,
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32, 34, 36, 38, 40, 42, 44, 46,
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49, 53, 57, 61, 65, 69, 73, 77,
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81, 85, 89, 93, 97, 101, 105, 109,
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115, 123, 131, 139, 147, 155, 163, 171,
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179, 187, 195, 203, 211, 219, 227, 235,
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247, 263, 279, 295, 311, 327, 343, 359,
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375, 391, 407, 423, 439, 455, 471, 487,
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511, 543, 575, 607, 639, 671, 703, 735,
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767, 799, 831, 863, 895, 927, 959, 991,
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1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487,
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1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999,
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2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991,
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3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015,
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};
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/*
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* This function is described into Taos TSL2550 Designer's Notebook
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* pages 2, 3.
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*/
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static int tsl2550_calculate_lux(u8 ch0, u8 ch1)
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{
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unsigned int lux;
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/* Look up count from channel values */
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u16 c0 = count_lut[ch0];
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u16 c1 = count_lut[ch1];
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/*
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* Calculate ratio.
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* Note: the "128" is a scaling factor
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*/
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u8 r = 128;
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/* Avoid division by 0 and count 1 cannot be greater than count 0 */
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if (c0 && (c1 <= c0))
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r = c1 * 128 / c0;
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else
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return -1;
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/* Calculate LUX */
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lux = ((c0 - c1) * ratio_lut[r]) / 256;
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/* LUX range check */
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return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux;
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}
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/*
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* SysFS support
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*/
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static ssize_t tsl2550_show_power_state(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
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return sprintf(buf, "%u\n", data->power_state);
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}
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static ssize_t tsl2550_store_power_state(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct tsl2550_data *data = i2c_get_clientdata(client);
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unsigned long val = simple_strtoul(buf, NULL, 10);
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int ret;
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if (val < 0 || val > 1)
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return -EINVAL;
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mutex_lock(&data->update_lock);
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ret = tsl2550_set_power_state(client, val);
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mutex_unlock(&data->update_lock);
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if (ret < 0)
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return ret;
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return count;
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}
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static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
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tsl2550_show_power_state, tsl2550_store_power_state);
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static ssize_t tsl2550_show_operating_mode(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
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return sprintf(buf, "%u\n", data->operating_mode);
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}
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static ssize_t tsl2550_store_operating_mode(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct tsl2550_data *data = i2c_get_clientdata(client);
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unsigned long val = simple_strtoul(buf, NULL, 10);
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int ret;
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if (val < 0 || val > 1)
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return -EINVAL;
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if (data->power_state == 0)
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return -EBUSY;
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mutex_lock(&data->update_lock);
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ret = tsl2550_set_operating_mode(client, val);
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mutex_unlock(&data->update_lock);
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if (ret < 0)
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return ret;
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return count;
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}
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static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO,
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tsl2550_show_operating_mode, tsl2550_store_operating_mode);
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static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf)
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{
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u8 ch0, ch1;
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int ret;
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ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0);
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if (ret < 0)
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return ret;
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ch0 = ret;
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mdelay(1);
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ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1);
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if (ret < 0)
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return ret;
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ch1 = ret;
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/* Do the job */
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ret = tsl2550_calculate_lux(ch0, ch1);
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if (ret < 0)
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return ret;
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return sprintf(buf, "%d\n", ret);
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}
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static ssize_t tsl2550_show_lux1_input(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct tsl2550_data *data = i2c_get_clientdata(client);
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int ret;
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/* No LUX data if not operational */
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if (!data->power_state)
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return -EBUSY;
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mutex_lock(&data->update_lock);
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ret = __tsl2550_show_lux(client, buf);
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mutex_unlock(&data->update_lock);
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return ret;
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}
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static DEVICE_ATTR(lux1_input, S_IRUGO,
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tsl2550_show_lux1_input, NULL);
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static struct attribute *tsl2550_attributes[] = {
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&dev_attr_power_state.attr,
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&dev_attr_operating_mode.attr,
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&dev_attr_lux1_input.attr,
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NULL
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};
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static const struct attribute_group tsl2550_attr_group = {
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.attrs = tsl2550_attributes,
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};
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/*
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* Initialization function
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*/
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static void tsl2550_init_client(struct i2c_client *client)
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{
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struct tsl2550_data *data = i2c_get_clientdata(client);
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/* Power up the device and set the default operating mode */
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tsl2550_set_power_state(client, 1);
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tsl2550_set_operating_mode(client, data->operating_mode);
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}
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/*
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* I2C init/probing/exit functions
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*/
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static struct i2c_driver tsl2550_driver;
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static int __devinit tsl2550_probe(struct i2c_client *client)
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{
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struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
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struct tsl2550_data *data;
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int *opmode, err = 0;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) {
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err = -EIO;
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goto exit;
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}
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data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL);
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if (!data) {
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err = -ENOMEM;
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goto exit;
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}
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data->client = client;
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i2c_set_clientdata(client, data);
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/* Check platform data */
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opmode = client->dev.platform_data;
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if (opmode) {
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if (*opmode < 0 || *opmode > 1) {
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dev_err(&client->dev, "invalid operating_mode (%d)\n",
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*opmode);
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err = -EINVAL;
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goto exit_kfree;
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}
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data->operating_mode = *opmode;
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} else
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data->operating_mode = 0; /* default mode is standard */
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dev_info(&client->dev, "%s operating mode\n",
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data->operating_mode ? "extended" : "standard");
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/*
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* Probe the chip. To do so we try to power up the device and then to
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* read back the 0x03 code
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*/
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err = i2c_smbus_write_byte(client, TSL2550_POWER_UP);
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if (err < 0)
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goto exit_kfree;
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mdelay(1);
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err = i2c_smbus_read_byte(client);
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if (err != TSL2550_POWER_UP) {
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err = -ENODEV;
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goto exit_kfree;
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}
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mutex_init(&data->update_lock);
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/* Initialize the TSL2550 chip */
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tsl2550_init_client(client);
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/* Register sysfs hooks */
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err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group);
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if (err)
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goto exit_kfree;
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dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
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return 0;
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exit_kfree:
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kfree(data);
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exit:
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return err;
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}
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static int __devexit tsl2550_remove(struct i2c_client *client)
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{
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sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group);
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/* Power down the device */
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tsl2550_set_power_state(client, 0);
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kfree(i2c_get_clientdata(client));
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return 0;
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}
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static struct i2c_driver tsl2550_driver = {
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.driver = {
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.name = TSL2550_DRV_NAME,
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.owner = THIS_MODULE,
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},
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.probe = tsl2550_probe,
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.remove = __devexit_p(tsl2550_remove),
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};
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static int __init tsl2550_init(void)
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{
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return i2c_add_driver(&tsl2550_driver);
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}
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static void __exit tsl2550_exit(void)
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{
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i2c_del_driver(&tsl2550_driver);
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}
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|
||||
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);
|
||||
Loading…
Reference in New Issue
Block a user