From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753430AbZFPEQS (ORCPT ); Tue, 16 Jun 2009 00:16:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750791AbZFPEQK (ORCPT ); Tue, 16 Jun 2009 00:16:10 -0400 Received: from 130.120.124.202.static.snap.net.nz ([202.124.120.130]:46428 "EHLO hayes.bluewaternz.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750824AbZFPEQI (ORCPT ); Tue, 16 Jun 2009 00:16:08 -0400 Message-ID: <4A371CDF.3070407@bluewatersys.com> Date: Tue, 16 Jun 2009 16:17:35 +1200 From: Ryan Mallon User-Agent: Thunderbird 2.0.0.21 (X11/20090318) MIME-Version: 1.0 To: linux kernel , linux-i2c@vger.kernel.org Subject: [PATCH] ds2782 battery gas gauge driver X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add support for the the ds2782 standalone I2C gas-gauge. Signed-off-by: Ryan Mallon --- diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig index 33da112..b9c818f 100644 --- a/drivers/power/Kconfig +++ b/drivers/power/Kconfig @@ -43,6 +43,13 @@ config BATTERY_DS2760 help Say Y here to enable support for batteries with ds2760 chip. +config BATTERY_DS2782 + tristate "DS2782 standalone gas-gauge" + depends on I2C + help + Say Y here to enable support for the DS2782 standalone battery + gas-gauge. + config BATTERY_PMU tristate "Apple PMU battery" depends on PPC32 && ADB_PMU diff --git a/drivers/power/Makefile b/drivers/power/Makefile index 2fcf41d..ad1ac61 100644 --- a/drivers/power/Makefile +++ b/drivers/power/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_APM_POWER) += apm_power.o obj-$(CONFIG_WM8350_POWER) += wm8350_power.o obj-$(CONFIG_BATTERY_DS2760) += ds2760_battery.o +obj-$(CONFIG_BATTERY_DS2782) += ds2782_battery.o obj-$(CONFIG_BATTERY_PMU) += pmu_battery.o obj-$(CONFIG_BATTERY_OLPC) += olpc_battery.o obj-$(CONFIG_BATTERY_TOSA) += tosa_battery.o diff --git a/drivers/power/ds2782_battery.c b/drivers/power/ds2782_battery.c new file mode 100644 index 0000000..8697891 --- /dev/null +++ b/drivers/power/ds2782_battery.c @@ -0,0 +1,269 @@ +/* + * drivers/power/ds2782_battery.c + * + * I2C client/driver for the Maxim/Dallas DS2782 Stand-Alone Fuel Gauge IC + * + * Copyright (C) 2009 Bluewater Systems Ltd + * Author: Ryan Mallon + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include +#include +#include +#include +#include + +#define DS2782_REG_RARC 0x06 /* Remaining active relative capacity */ + +#define DS2782_REG_VOLT_MSB 0x0c +#define DS2782_REG_TEMP_MSB 0x0a +#define DS2782_REG_CURRENT_MSB 0x0e + +/* EEPROM Block */ +#define DS2782_REG_RSNSP 0x69 /* Sense resistor value */ + +/* Current unit measurement in uA for a 1 milli-ohm sense resistor */ +#define DS2782_CURRENT_UNITS 1563 + +#define to_ds2782_info(x) container_of(x, struct ds2782_info, battery) + +struct ds2782_info { + struct i2c_client *client; + struct power_supply battery; + int id; +}; + +static DEFINE_IDR(battery_id); +static DEFINE_MUTEX(battery_lock); + +static inline u8 ds2782_read_reg(struct ds2782_info *info, int reg) +{ + return i2c_smbus_read_byte_data(info->client, reg); +} + +static inline u16 ds2782_read_reg16(struct ds2782_info *info, int reg_msb) +{ + u8 msb, lsb; + + msb = ds2782_read_reg(info, reg_msb); + lsb = ds2782_read_reg(info, reg_msb + 1); + + return (msb << 8) | lsb; +} + +static int ds2782_get_temp(struct ds2782_info *info) +{ + u16 raw; + s16 temp; + + /* Temperature is measured in units of 0.125 degrees celcius */ + raw = ds2782_read_reg16(info, DS2782_REG_TEMP_MSB); + temp = (raw >> 5) & 0x7ff; + if (raw & (1 << 15)) + temp |= 0xf800; + return (temp * 125) / 100; +} + +static int ds2782_get_current(struct ds2782_info *info) +{ + s16 current_uA; + int sense_res; + + /* + * The units of measurement for current are dependent on the value of + * the sense resistor. + */ + sense_res = 1000 / ds2782_read_reg(info, DS2782_REG_RSNSP); + dev_dbg(&info->client->dev, "sense resistor = %d milli-ohms\n", + sense_res); + current_uA = ds2782_read_reg16(info, DS2782_REG_CURRENT_MSB); + return current_uA * (DS2782_CURRENT_UNITS / sense_res); +} + +static int ds2782_get_voltage(struct ds2782_info *info) +{ + u16 raw; + s16 voltage_uA; + + /* Voltage is measured in units of 4.88mV */ + raw = ds2782_read_reg16(info, DS2782_REG_VOLT_MSB); + voltage_uA = (raw >> 5) & 0x7ff; + if (raw & (1 << 15)) + voltage_uA |= 0xf800; + return voltage_uA * 4880; +} + +static int ds2782_get_status(struct ds2782_info *info) +{ + int current_uA, capacity; + + current_uA = ds2782_get_current(info); + capacity = ds2782_read_reg(info, DS2782_REG_RARC); + + if (capacity == 100) + return POWER_SUPPLY_STATUS_FULL; + else if (current_uA == 0) + return POWER_SUPPLY_STATUS_NOT_CHARGING; + else if (current_uA < 0) + return POWER_SUPPLY_STATUS_DISCHARGING; + else + return POWER_SUPPLY_STATUS_CHARGING; +} + +static int ds2782_battery_get_property(struct power_supply *psy, + enum power_supply_property prop, + union power_supply_propval *val) +{ + struct ds2782_info *info = to_ds2782_info(psy); + + switch (prop) { + case POWER_SUPPLY_PROP_STATUS: + val->intval = ds2782_get_status(info); + break; + + case POWER_SUPPLY_PROP_CAPACITY: + val->intval = ds2782_read_reg(info, DS2782_REG_RARC); + break; + + case POWER_SUPPLY_PROP_VOLTAGE_NOW: + val->intval = ds2782_get_voltage(info); + break; + + case POWER_SUPPLY_PROP_CURRENT_NOW: + val->intval = ds2782_get_current(info); + break; + + case POWER_SUPPLY_PROP_TEMP: + val->intval = ds2782_get_temp(info); + break; + + default: + return -EINVAL; + } + + return 0; +} + +static enum power_supply_property ds2782_battery_props[] = { + POWER_SUPPLY_PROP_STATUS, + POWER_SUPPLY_PROP_CAPACITY, + POWER_SUPPLY_PROP_VOLTAGE_NOW, + POWER_SUPPLY_PROP_CURRENT_NOW, + POWER_SUPPLY_PROP_TEMP, +}; + +static void ds2782_power_supply_init(struct power_supply *battery) +{ + battery->type = POWER_SUPPLY_TYPE_BATTERY; + battery->properties = ds2782_battery_props; + battery->num_properties = ARRAY_SIZE(ds2782_battery_props); + battery->get_property = ds2782_battery_get_property; + battery->external_power_changed = NULL; +} + +static int ds2782_battery_remove(struct i2c_client *client) +{ + struct ds2782_info *info = i2c_get_clientdata(client); + + power_supply_unregister(&info->battery); + kfree(info->battery.name); + + mutex_lock(&battery_lock); + idr_remove(&battery_id, info->id); + mutex_unlock(&battery_lock); + + kfree(info); + return 0; +} + +static int ds2782_battery_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct ds2782_info *info; + int ret, num; + + /* Get an ID for this battery */ + ret = idr_pre_get(&battery_id, GFP_KERNEL); + if (ret == 0) { + ret = -ENOMEM; + goto fail_id; + } + + mutex_lock(&battery_lock); + ret = idr_get_new(&battery_id, client, &num); + mutex_unlock(&battery_lock); + if (ret < 0) + return ret; + + info = kzalloc(sizeof(struct ds2782_info), GFP_KERNEL); + if (!info) { + ret = -ENOMEM; + goto fail_info; + } + + info->battery.name = kasprintf(GFP_KERNEL, "ds2782-%d", num); + if (!info->battery.name) { + ret = -ENOMEM; + goto fail_name; + } + + i2c_set_clientdata(client, info); + info->client = client; + ds2782_power_supply_init(&info->battery); + + ret = power_supply_register(&client->dev, &info->battery); + if (ret) { + dev_err(&client->dev, "failed to register battery\n"); + goto fail_register; + } + + return 0; + +fail_register: + kfree(info->battery.name); +fail_name: + kfree(info); +fail_info: + mutex_lock(&battery_lock); + idr_remove(&battery_id, num); + mutex_unlock(&battery_lock); +fail_id: + return ret; +} + +static const struct i2c_device_id ds2782_id[] = { + {"ds2782", 0}, + {}, +}; + +static struct i2c_driver ds2782_battery_driver = { + .driver = { + .name = "ds2782-battery", + }, + .probe = ds2782_battery_probe, + .remove = ds2782_battery_remove, + .id_table = ds2782_id, +}; + +static int __init ds2782_init(void) +{ + return i2c_add_driver(&ds2782_battery_driver); +} + +static void __exit ds2782_exit(void) +{ + i2c_del_driver(&ds2782_battery_driver); +} + +module_init(ds2782_init); +module_exit(ds2782_exit); + +MODULE_AUTHOR("Ryan Mallon "); +MODULE_DESCRIPTION("Maxim/Dallas DS2782 Stand-Alone Fuel Gauage IC driver"); +MODULE_LICENSE("GPL"); +