linux-imx

/*

 *  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/slab.h>

#include <linux/i2c.h>

#include <linux/mutex.h>

​

#define TSL2550_DRV_NAME    "tsl2550"

#define DRIVER_VERSION      "1.2"

​

/*

 * 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;