path: root/drivers/power/ab8500_btemp.c

/*
 * Copyright (C) ST-Ericsson SA 2012
 *
 * Battery temperature driver for AB8500
 *
 * License Terms: GNU General Public License v2
 * Author:
 *	Johan Palsson <johan.palsson@stericsson.com>
 *	Karl Komierowski <karl.komierowski@stericsson.com>
 *	Arun R Murthy <arun.murthy@stericsson.com>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/completion.h>
#include <linux/workqueue.h>
#include <linux/mfd/abx500/ab8500.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/abx500/ab8500-bm.h>
#include <linux/mfd/abx500/ab8500-gpadc.h>
#include <linux/jiffies.h>

#define VTVOUT_V			1800

#define BTEMP_THERMAL_LOW_LIMIT		-10
#define BTEMP_THERMAL_MED_LIMIT		0
#define BTEMP_THERMAL_HIGH_LIMIT_52	52
#define BTEMP_THERMAL_HIGH_LIMIT_57	57
#define BTEMP_THERMAL_HIGH_LIMIT_62	62

#define BTEMP_BATCTRL_CURR_SRC_7UA	7
#define BTEMP_BATCTRL_CURR_SRC_20UA	20

#define to_ab8500_btemp_device_info(x) container_of((x), \
	struct ab8500_btemp, btemp_psy);

/**
 * struct ab8500_btemp_interrupts - ab8500 interrupts
 * @name:	name of the interrupt
 * @isr		function pointer to the isr
 */
struct ab8500_btemp_interrupts {
	char *name;
	irqreturn_t (*isr)(int irq, void *data);
};

struct ab8500_btemp_events {
	bool batt_rem;
	bool btemp_high;
	bool btemp_medhigh;
	bool btemp_lowmed;
	bool btemp_low;
	bool ac_conn;
	bool usb_conn;
};

struct ab8500_btemp_ranges {
	int btemp_high_limit;
	int btemp_med_limit;
	int btemp_low_limit;
};

/**
 * struct ab8500_btemp - ab8500 BTEMP device information
 * @dev:		Pointer to the structure device
 * @node:		List of AB8500 BTEMPs, hence prepared for reentrance
 * @curr_source:	What current source we use, in uA
 * @bat_temp:		Battery temperature in degree Celcius
 * @prev_bat_temp	Last dispatched battery temperature
 * @parent:		Pointer to the struct ab8500
 * @gpadc:		Pointer to the struct gpadc
 * @fg:			Pointer to the struct fg
 * @pdata:		Pointer to the abx500_btemp platform data
 * @bat:		Pointer to the abx500_bm platform data
 * @btemp_psy:		Structure for BTEMP specific battery properties
 * @events:		Structure for information about events triggered
 * @btemp_ranges:	Battery temperature range structure
 * @btemp_wq:		Work queue for measuring the temperature periodically
 * @btemp_periodic_work:	Work for measuring the temperature periodically
 */
struct ab8500_btemp {
	struct device *dev;
	struct list_head node;
	int curr_source;
	int bat_temp;
	int prev_bat_temp;
	struct ab8500 *parent;
	struct ab8500_gpadc *gpadc;
	struct ab8500_fg *fg;
	struct abx500_bmdevs_plat_data *pdata;
	struct abx500_bm_data *bat;
	struct power_supply btemp_psy;
	struct ab8500_btemp_events events;
	struct ab8500_btemp_ranges btemp_ranges;
	struct workqueue_struct *btemp_wq;
	struct delayed_work btemp_periodic_work;
};

/* BTEMP power supply properties */
static enum power_supply_property ab8500_btemp_props[] = {
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_TEMP,
};

static LIST_HEAD(ab8500_btemp_list);

/**
 * ab8500_btemp_get() - returns a reference to the primary AB8500 BTEMP
 * (i.e. the first BTEMP in the instance list)
 */
struct ab8500_btemp *ab8500_btemp_get(void)
{
	struct ab8500_btemp *btemp;
	btemp = list_first_entry(&ab8500_btemp_list, struct ab8500_btemp, node);

	return btemp;
}

/**
 * ab8500_btemp_batctrl_volt_to_res() - convert batctrl voltage to resistance
 * @di:		pointer to the ab8500_btemp structure
 * @v_batctrl:	measured batctrl voltage
 * @inst_curr:	measured instant current
 *
 * This function returns the battery resistance that is
 * derived from the BATCTRL voltage.
 * Returns value in Ohms.
 */
static int ab8500_btemp_batctrl_volt_to_res(struct ab8500_btemp *di,
	int v_batctrl, int inst_curr)
{
	int rbs;

	if (is_ab8500_1p1_or_earlier(di->parent)) {
		/*
		 * For ABB cut1.0 and 1.1 BAT_CTRL is internally
		 * connected to 1.8V through a 450k resistor
		 */
		return (450000 * (v_batctrl)) / (1800 - v_batctrl);
	}

	if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL) {
		/*
		 * If the battery has internal NTC, we use the current
		 * source to calculate the resistance, 7uA or 20uA
		 */
		rbs = (v_batctrl * 1000
		       - di->bat->gnd_lift_resistance * inst_curr)
		      / di->curr_source;
	} else {
		/*
		 * BAT_CTRL is internally
		 * connected to 1.8V through a 80k resistor
		 */
		rbs = (80000 * (v_batctrl)) / (1800 - v_batctrl);
	}

	return rbs;
}

/**
 * ab8500_btemp_read_batctrl_voltage() - measure batctrl voltage
 * @di:		pointer to the ab8500_btemp structure
 *
 * This function returns the voltage on BATCTRL. Returns value in mV.
 */
static int ab8500_btemp_read_batctrl_voltage(struct ab8500_btemp *di)
{
	int vbtemp;
	static int prev;

	vbtemp = ab8500_gpadc_convert(di->gpadc