include/linux/mfd/pm8xxx/ccadc.h

/* Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * 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.
 */

#ifndef __PMIC8XXX_CCADC_H__
#define __PMIC8XXX_CCADC_H__

#include <linux/mfd/pm8xxx/core.h>

#define PM8XXX_CCADC_DEV_NAME "pm8xxx-ccadc"

struct pm8xxx_ccadc_core_data {
	unsigned int	batt_temp_channel;
};

/**
 * struct pm8xxx_ccadc_platform_data -
 * @ccadc_cdata:	core data for the ccadc driver containing channel info
 * @r_sense_uohm:		sense resistor value in (micro Ohms)
 * @calib_delay_ms:	how often should the adc calculate gain and offset
 * @periodic_wakeup:	a flag to indicate that this system wakeups periodically
 *			for calibration/other housekeeping activities. The ccadc
 *			does a quick calibration while resuming
 */
struct pm8xxx_ccadc_platform_data {
	struct pm8xxx_ccadc_core_data	ccadc_cdata;
	int				r_sense_uohm;
	unsigned int			calib_delay_ms;
	bool				periodic_wakeup;
};

#define CCADC_READING_RESOLUTION_N	542535
#define CCADC_READING_RESOLUTION_D	100000

static inline s64 pm8xxx_ccadc_reading_to_microvolt(int revision, s64 cc)
{
	return div_s64(cc * CCADC_READING_RESOLUTION_N,
					CCADC_READING_RESOLUTION_D);
}

#if defined(CONFIG_PM8XXX_CCADC) || defined(CONFIG_PM8XXX_CCADC_MODULE)
/**
 * pm8xxx_cc_adjust_for_gain - the function to adjust the voltage read from
 *			ccadc for gain compensation
 * @v:	the voltage which needs to be gain compensated in microVolts
 *
 *
 * RETURNS: gain compensated voltage
 */
s64 pm8xxx_cc_adjust_for_gain(s64 uv);

/**
 * pm8xxx_calib_ccadc - calibration for ccadc. This will calculate gain
 *			and offset and reprogram them in the appropriate
 *			registers
 */
void pm8xxx_calib_ccadc(void);

/**
 * pm8xxx_ccadc_get_battery_current - return the battery current based on vsense
 *				resitor in microamperes
 * @result:	The pointer where the voltage will be updated. A -ve
 *		result means that the current is flowing in
 *		the battery - during battery charging
 *
 * RETURNS:	Error code if there was a problem reading vsense, Zero otherwise
 *		The result won't be updated in case of an error.
 *
 */
int pm8xxx_ccadc_get_battery_current(int *bat_current);
#else
static inline s64 pm8xxx_cc_adjust_for_gain(s64 uv)
{
	return -ENXIO;
}
static inline void pm8xxx_calib_ccadc(void)
{
}
static inline int pm8xxx_ccadc_get_battery_current(int *bat_current)
{
	return -ENXIO;
}
#endif

#endif /* __PMIC8XXX_CCADC_H__ */