path: root/drivers/power/supply/ds2760_battery.c

/*
 * Driver for batteries with DS2760 chips inside.
 *
 * Copyright © 2007 Anton Vorontsov
 *	       2004-2007 Matt Reimer
 *	       2004 Szabolcs Gyurko
 *
 * Use consistent with the GNU GPL is permitted,
 * provided that this copyright notice is
 * preserved in its entirety in all copies and derived works.
 *
 * Author:  Anton Vorontsov <cbou@mail.ru>
 *	    February 2007
 *
 *	    Matt Reimer <mreimer@vpop.net>
 *	    April 2004, 2005, 2007
 *
 *	    Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
 *	    September 2004
 */

#include <linux/module.h>
#include <linux/param.h>
#include <linux/jiffies.h>
#include <linux/workqueue.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/suspend.h>
#include <linux/w1.h>
#include <linux/of.h>

static unsigned int cache_time = 1000;
module_param(cache_time, uint, 0644);
MODULE_PARM_DESC(cache_time, "cache time in milliseconds");

static bool pmod_enabled;
module_param(pmod_enabled, bool, 0644);
MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");

static unsigned int rated_capacity;
module_param(rated_capacity, uint, 0644);
MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");

static unsigned int current_accum;
module_param(current_accum, uint, 0644);
MODULE_PARM_DESC(current_accum, "current accumulator value");

#define W1_FAMILY_DS2760		0x30

/* Known commands to the DS2760 chip */
#define W1_DS2760_SWAP			0xAA
#define W1_DS2760_READ_DATA		0x69
#define W1_DS2760_WRITE_DATA		0x6C
#define W1_DS2760_COPY_DATA		0x48
#define W1_DS2760_RECALL_DATA		0xB8
#define W1_DS2760_LOCK			0x6A

/* Number of valid register addresses */
#define DS2760_DATA_SIZE		0x40

#define DS2760_PROTECTION_REG		0x00

#define DS2760_STATUS_REG		0x01
#define DS2760_STATUS_IE		(1 << 2)
#define DS2760_STATUS_SWEN		(1 << 3)
#define DS2760_STATUS_RNAOP		(1 << 4)
#define DS2760_STATUS_PMOD		(1 << 5)

#define DS2760_EEPROM_REG		0x07
#define DS2760_SPECIAL_FEATURE_REG	0x08
#define DS2760_VOLTAGE_MSB		0x0c
#define DS2760_VOLTAGE_LSB		0x0d
#define DS2760_CURRENT_MSB		0x0e
#define DS2760_CURRENT_LSB		0x0f
#define DS2760_CURRENT_ACCUM_MSB	0x10
#define DS2760_CURRENT_ACCUM_LSB	0x11
#define DS2760_TEMP_MSB			0x18
#define DS2760_TEMP_LSB			0x19
#define DS2760_EEPROM_BLOCK0		0x20
#define DS2760_ACTIVE_FULL		0x20
#define DS2760_EEPROM_BLOCK1		0x30
#define DS2760_STATUS_WRITE_REG		0x31
#define DS2760_RATED_CAPACITY		0x32
#define DS2760_CURRENT_OFFSET_BIAS	0x33
#define DS2760_ACTIVE_EMPTY		0x3b

struct ds2760_device_info {
	struct device *dev;

	/* DS2760 data, valid after calling ds2760_battery_read_status() */
	unsigned long update_time;	/* jiffies when data read */
	char raw[DS2760_DATA_SIZE];	/* raw DS2760 data */
	int voltage_raw;		/* units of 4.88 mV */
	int voltage_uV;			/* units of µV */
	int current_raw;		/* units of 0.625 mA */
	int current_uA;			/* units of µA */
	int accum_current_raw;		/* units of 0.25 mAh */
	int accum_current_uAh;		/* units of µAh */
	int temp_raw;			/* units of 0.125 °C */
	int temp_C;			/* units of 0.1 °C */
	int rated_capacity;		/* units of µAh */
	int rem_capacity;		/* percentage */
	int full_active_uAh;		/* units of µAh */
	int empty_uAh;			/* units of µAh */
	int life_sec;			/* units of seconds */
	int charge_status;		/* POWER_SUPPLY_STATUS_* */

	int full_counter;
	struct power_supply *bat;
	struct power_supply_desc bat_desc;
	struct workqueue_struct *monitor_wqueue;
	struct delayed_work monitor_work;
	struct delayed_work set_charged_work;
	struct notifier_block pm_notifier;
};

static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
			int io)
{
	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);

	if (!dev)
		return 0;

	mutex_lock(&sl->master->bus_mutex);

	if (addr > DS2760_DATA_SIZE || addr < 0) {
		count = 0;
		goto out;
	}
	if (addr + count > DS2760_DATA_SIZE)
		count = DS2760_DATA_SIZE - addr;

	if (!w1_reset_select_slave(sl)) {
		if (!io) {
			w1_write_8(sl->master, W1_DS2760_READ_DATA);
			w1_write_8(sl->master, addr);
			count = w1_read_block(sl->master, buf, count);
		} else {
			w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
			w1_write_8(sl->master, addr);
			w1_write_block(sl->master, buf, count);
			/* XXX w1_write_block returns void, not n_written */
		}
	}

out:
	mutex_unlock(&sl->master->bus_mutex);

	return count;
}

static int w1_ds2760_read(struct device *dev,
			  char *buf, int addr,
			  size_t count)
{
	return w1_ds2760_io(dev, buf, addr, count, 0);
}

static int w1_ds2760_write(struct device *dev,
			   char *buf,
			   int addr, size_t count)
{
	return w1_ds2760_io(dev, buf, addr, count, 1);
}

static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
{
	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);

	if (!dev)
		return -EINVAL;

	mutex_lock(&sl->master->bus_mutex);

	if (w1_reset_select_slave(sl) == 0) {
		w1_write_8(sl->master, cmd);
		w1_write_8(sl->master, addr);
	}

	mutex_unlock(&sl->master->bus_mutex);
	return 0;
}

static int w1_ds2760_store_eeprom(struct device *dev, int addr)
{
	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
}

static int w1_ds2760_recall_eeprom(struct device *dev, int addr)
{
	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
}

static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
			     struct bin_attribute *bin_attr, char *buf,
			     loff_t off, size_t count)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	return w1_ds2760_read(dev, buf, off, count);
}

static BIN_AT