power_supply: Add bq2415x charger driver

/*

    bq2415x_charger.h - bq2415x charger driver

    Copyright (C) 2011-2012  Pali Rohár <pali.rohar@gmail.com>

    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.,

    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

*/

#ifndef BQ2415X_CHARGER_H

#define BQ2415X_CHARGER_H

/*

  This is platform data for bq2415x chip. It contains default board voltages

  and currents which can be also later configured via sysfs. If value is -1

  then default chip value (specified in datasheet) will be used.

  Value resistor_sense is needed for for configuring charge and termination

  current. It it is less or equal to zero, configuring charge and termination

  current will not be possible.

  Function set_mode_hook is needed for automode (setting correct current limit

  when charger is connected/disconnected or setting boost mode). When is NULL,

  automode function is disabled. When is not NULL, it must have this prototype:

    int (*set_mode_hook)(

      void (*hook)(enum bq2415x_mode mode, void *data),

      void *data)

  hook is hook function (see below) and data is pointer to driver private data

  bq2415x driver will call it as:

    platform_data->set_mode_hook(bq2415x_hook_function, bq2415x_device);

  Board/platform function set_mode_hook return non zero value when hook

  function was successful registered. Platform code should call that hook

  function (which get from pointer, with data) every time when charger was

  connected/disconnected or require to enable boost mode. bq2415x driver then

  will set correct current limit, enable/disable charger or boost mode.

  Hook function has this prototype:

    void hook(enum bq2415x_mode mode, void *data);

  mode is bq2415x mode (charger or boost)

  data is pointer to driver private data (which get from set_charger_type_hook)

  When bq driver is being unloaded, it call function:

    platform_data->set_mode_hook(NULL, NULL);

  (hook function and driver private data are NULL)

  After that board/platform code must not call driver hook function! It is

  possible that pointer to hook function will not be valid and calling will

  cause undefined result.

*/

/* Supported modes with maximal current limit */

enum bq2415x_mode {

	BQ2415X_MODE_NONE,		/* unknown or no charger (100mA) */

	BQ2415X_MODE_HOST_CHARGER,	/* usb host/hub charger (500mA) */

	BQ2415X_MODE_DEDICATED_CHARGER, /* dedicated charger (unlimited) */

	BQ2415X_MODE_BOOST,		/* boost mode (charging disabled) */

};

struct bq2415x_platform_data {

	int current_limit;		/* mA */

	int weak_battery_voltage;	/* mV */

	int battery_regulation_voltage;	/* mV */

	int charge_current;		/* mA */

	int termination_current;	/* mA */

	int resistor_sense;		/* m ohm */

	int (*set_mode_hook)(void (*hook)(enum bq2415x_mode mode, void *data),

			     void *data);

};

#endif