From 04a820ead0838c76e9c1242feb5e71048bf3e9dc Mon Sep 17 00:00:00 2001 From: Andres Salomon Date: Tue, 30 Jun 2009 02:14:00 -0400 Subject: [PATCH 1/3] olpc_battery: Fix up eeprom read function The eeprom read function was placing values into the wrong place in 'buf'; we were starting from buf[off], rather than buf[0]. Also, the for loop that we were using was much uglier than it needed to be. This cleans it up a bit. Signed-off-by: Andres Salomon Signed-off-by: Anton Vorontsov --- drivers/power/olpc_battery.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/power/olpc_battery.c b/drivers/power/olpc_battery.c index 5fbca2681baa..9c216dd41550 100644 --- a/drivers/power/olpc_battery.c +++ b/drivers/power/olpc_battery.c @@ -8,6 +8,7 @@ * published by the Free Software Foundation. */ +#include #include #include #include @@ -334,21 +335,21 @@ static ssize_t olpc_bat_eeprom_read(struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { uint8_t ec_byte; - int ret, end; + int ret; + int i; if (off >= EEPROM_SIZE) return 0; if (off + count > EEPROM_SIZE) count = EEPROM_SIZE - off; - end = EEPROM_START + off + count; - for (ec_byte = EEPROM_START + off; ec_byte < end; ec_byte++) { - ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, - &buf[ec_byte - EEPROM_START], 1); + for (i = 0; i < count; i++) { + ec_byte = EEPROM_START + off + i; + ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1); if (ret) { - printk(KERN_ERR "olpc-battery: EC command " - "EC_BAT_EEPROM @ 0x%x failed -" - " %d!\n", ec_byte, ret); + pr_err("olpc-battery: " + "EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n", + ec_byte, ret); return -EIO; } } From 8f7e57985fa794ab6afdcd3642581d9e1fe6de31 Mon Sep 17 00:00:00 2001 From: Andres Salomon Date: Tue, 30 Jun 2009 02:16:17 -0400 Subject: [PATCH 2/3] olpc_battery: Ensure that the TRICKLE bit is checked There are times when the battery is present but trickle charging, and the EC sets only the TRICKLE bit. So we must check for the bit when we're checking the charging/present status. Signed-off-by: Andres Salomon Signed-off-by: Anton Vorontsov --- drivers/power/olpc_battery.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/power/olpc_battery.c b/drivers/power/olpc_battery.c index 9c216dd41550..58e419299cd6 100644 --- a/drivers/power/olpc_battery.c +++ b/drivers/power/olpc_battery.c @@ -36,6 +36,7 @@ #define BAT_STAT_AC 0x10 #define BAT_STAT_CHARGING 0x20 #define BAT_STAT_DISCHARGING 0x40 +#define BAT_STAT_TRICKLE 0x80 #define BAT_ERR_INFOFAIL 0x02 #define BAT_ERR_OVERVOLTAGE 0x04 @@ -90,7 +91,7 @@ static char bat_serial[17]; /* Ick */ static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte) { if (olpc_platform_info.ecver > 0x44) { - if (ec_byte & BAT_STAT_CHARGING) + if (ec_byte & (BAT_STAT_CHARGING | BAT_STAT_TRICKLE)) val->intval = POWER_SUPPLY_STATUS_CHARGING; else if (ec_byte & BAT_STAT_DISCHARGING) val->intval = POWER_SUPPLY_STATUS_DISCHARGING; @@ -220,7 +221,8 @@ static int olpc_bat_get_property(struct power_supply *psy, It doesn't matter though -- the EC will return the last-known information, and it's as if we just ran that _little_ bit faster and managed to read it out before the battery went away. */ - if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT) + if (!(ec_byte & (BAT_STAT_PRESENT | BAT_STAT_TRICKLE)) && + psp != POWER_SUPPLY_PROP_PRESENT) return -ENODEV; switch (psp) { @@ -230,7 +232,8 @@ static int olpc_bat_get_property(struct power_supply *psy, return ret; break; case POWER_SUPPLY_PROP_PRESENT: - val->intval = !!(ec_byte & BAT_STAT_PRESENT); + val->intval = !!(ec_byte & (BAT_STAT_PRESENT | + BAT_STAT_TRICKLE)); break; case POWER_SUPPLY_PROP_HEALTH: From bfdb46ce8494eae30dbaae65c81e684e6db6228b Mon Sep 17 00:00:00 2001 From: Ryan Mallon Date: Thu, 18 Jun 2009 11:26:26 +1200 Subject: [PATCH 3/3] Add ds2782 battery gas gauge driver This patch adds a driver for ds2782 battery devices. Signed-off-by: Ryan Mallon Signed-off-by: Anton Vorontsov --- drivers/power/Kconfig | 7 + drivers/power/Makefile | 1 + drivers/power/ds2782_battery.c | 330 +++++++++++++++++++++++++++++++++ 3 files changed, 338 insertions(+) create mode 100644 drivers/power/ds2782_battery.c diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig index 7eda34838bfe..bdbc4f73fcdc 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 daf3179689aa..380d17c9ae29 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 000000000000..da14f374cb60 --- /dev/null +++ b/drivers/power/ds2782_battery.c @@ -0,0 +1,330 @@ +/* + * 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 +#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 int ds2782_read_reg(struct ds2782_info *info, int reg, u8 *val) +{ + int ret; + + ret = i2c_smbus_read_byte_data(info->client, reg); + if (ret < 0) { + dev_err(&info->client->dev, "register read failed\n"); + return ret; + } + + *val = ret; + return 0; +} + +static inline int ds2782_read_reg16(struct ds2782_info *info, int reg_msb, + s16 *val) +{ + int ret; + + ret = swab16(i2c_smbus_read_word_data(info->client, reg_msb)); + if (ret < 0) { + dev_err(&info->client->dev, "register read failed\n"); + return ret; + } + + *val = ret; + return 0; +} + +static int ds2782_get_temp(struct ds2782_info *info, int *temp) +{ + s16 raw; + int err; + + /* + * Temperature is measured in units of 0.125 degrees celcius, the + * power_supply class measures temperature in tenths of degrees + * celsius. The temperature value is stored as a 10 bit number, plus + * sign in the upper bits of a 16 bit register. + */ + err = ds2782_read_reg16(info, DS2782_REG_TEMP_MSB, &raw); + if (err) + return err; + *temp = ((raw / 32) * 125) / 100; + return 0; +} + +static int ds2782_get_current(struct ds2782_info *info, int *current_uA) +{ + int sense_res; + int err; + u8 sense_res_raw; + s16 raw; + + /* + * The units of measurement for current are dependent on the value of + * the sense resistor. + */ + err = ds2782_read_reg(info, DS2782_REG_RSNSP, &sense_res_raw); + if (err) + return err; + if (sense_res_raw == 0) { + dev_err(&info->client->dev, "sense resistor value is 0\n"); + return -ENXIO; + } + sense_res = 1000 / sense_res_raw; + + dev_dbg(&info->client->dev, "sense resistor = %d milli-ohms\n", + sense_res); + err = ds2782_read_reg16(info, DS2782_REG_CURRENT_MSB, &raw); + if (err) + return err; + *current_uA = raw * (DS2782_CURRENT_UNITS / sense_res); + return 0; +} + +static int ds2782_get_voltage(struct ds2782_info *info, int *voltage_uA) +{ + s16 raw; + int err; + + /* + * Voltage is measured in units of 4.88mV. The voltage is stored as + * a 10-bit number plus sign, in the upper bits of a 16-bit register + */ + err = ds2782_read_reg16(info, DS2782_REG_VOLT_MSB, &raw); + if (err) + return err; + *voltage_uA = (raw / 32) * 4800; + return 0; +} + +static int ds2782_get_capacity(struct ds2782_info *info, int *capacity) +{ + int err; + u8 raw; + + err = ds2782_read_reg(info, DS2782_REG_RARC, &raw); + if (err) + return err; + *capacity = raw; + return raw; +} + +static int ds2782_get_status(struct ds2782_info *info, int *status) +{ + int err; + int current_uA; + int capacity; + + err = ds2782_get_current(info, ¤t_uA); + if (err) + return err; + + err = ds2782_get_capacity(info, &capacity); + if (err) + return err; + + if (capacity == 100) + *status = POWER_SUPPLY_STATUS_FULL; + else if (current_uA == 0) + *status = POWER_SUPPLY_STATUS_NOT_CHARGING; + else if (current_uA < 0) + *status = POWER_SUPPLY_STATUS_DISCHARGING; + else + *status = POWER_SUPPLY_STATUS_CHARGING; + + return 0; +} + +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); + int ret; + + switch (prop) { + case POWER_SUPPLY_PROP_STATUS: + ret = ds2782_get_status(info, &val->intval); + break; + + case POWER_SUPPLY_PROP_CAPACITY: + ret = ds2782_get_capacity(info, &val->intval); + break; + + case POWER_SUPPLY_PROP_VOLTAGE_NOW: + ret = ds2782_get_voltage(info, &val->intval); + break; + + case POWER_SUPPLY_PROP_CURRENT_NOW: + ret = ds2782_get_current(info, &val->intval); + break; + + case POWER_SUPPLY_PROP_TEMP: + ret = ds2782_get_temp(info, &val->intval); + break; + + default: + ret = -EINVAL; + } + + return ret; +} + +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); + + i2c_set_clientdata(client, info); + + 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; + int 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) + goto fail_id; + + info = kzalloc(sizeof(*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: + i2c_set_clientdata(client, info); + 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); +} +module_init(ds2782_init); + +static void __exit ds2782_exit(void) +{ + i2c_del_driver(&ds2782_battery_driver); +} +module_exit(ds2782_exit); + +MODULE_AUTHOR("Ryan Mallon "); +MODULE_DESCRIPTION("Maxim/Dallas DS2782 Stand-Alone Fuel Gauage IC driver"); +MODULE_LICENSE("GPL");