[PATCH v2 0/2] power: introduce Charger-Manager

[PATCH v2 0/2] power: introduce Charger-Manager

[Donggeun Kim]

Charger Manager provides in-kernel battery charger management that
requires temperature monitoring during both normal and suspend-to-RAM states
and where each battery may have multiple chargers attached and the userland
wants to look at the aggregated information of the multiple chargers.

Charger Manager is a platform_driver with power-supply-class entries.
An instance of Charger Manager (a platform-device created with
Charger-Manager) represents a battery with chargers. If there are multiple
batteries with their own chargers acting independently in a system,
the system may need multiple instances of Charger Manager.
Multiple chargers (e.g., USB, wireless, and solar panels) may be included
as pairs of a regulator and a power-supply-class
per charger.

Charger Manager glues multiple charger-related frameworks (regulators of
chargers, power-supply-class from chargers and fuel-gauge, RTC,
suspend-again, ...) together to provide aggregated information and
transparent battery monitoring to userspace.

For the discussions about the need for in-suspend monitoring, please
refer to the discussions of suspend-again in PM:
v1 https://lists.linux-foundation.org/pipermail/linux-pm/2011-April/031052.html
v2 https://lists.linux-foundation.org/pipermail/linux-pm/2011-April/031111.html
v3 https://lists.linux-foundation.org/pipermail/linux-pm/2011-May/031267.html
v4 https://lists.linux-foundation.org/pipermail/linux-pm/2011-May/031357.html
v5 (last, applied) https://lists.linux-foundation.org/pipermail/linux-pm/2011-June/031561.html

To see the usage example, please refer to:
http://git.infradead.org/users/kmpark/linux-2.6-samsung/shortlog/refs/heads/charger-manager
In this git branch, a test code for Exynos4-NURI is shown.

This patch set supports initial Charger Manager driver.
---
Changes for v2:
    - change symbol type of Kconfig to boolean

Donggeun Kim (2):
  power: Charger-Manager: add initial Charger-Manager driver
  power: Charger-Manager: add properties for power-supply-class

 Documentation/power/charger-manager.txt |  164 +++++
 drivers/power/Kconfig                   |    9 +
 drivers/power/Makefile                  |    1 +
 drivers/power/charger-manager.c         | 1064 +++++++++++++++++++++++++++++++
 include/linux/power/charger-manager.h   |  148 +++++
 5 files changed, 1386 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/power/charger-manager.txt
 create mode 100644 drivers/power/charger-manager.c
 create mode 100644 include/linux/power/charger-manager.h

-- 
1.7.4.1

[PATCH v2 1/2] power: Charger-Manager: add initial Charger-Manager driver

[Donggeun Kim]

Because battery health monitoring should be done even when suspended,
it needs to wake up and suspend periodically. Thus, userspace battery
monitoring may incur too much overhead; every device and task is woken
up periodically. Charger Manager uses suspend-again to provide
in-suspend monitoring.

This patch allows to monitor battery health in-suspend state.

Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 Documentation/power/charger-manager.txt |  150 ++++++
 drivers/power/Kconfig                   |    9 +
 drivers/power/Makefile                  |    1 +
 drivers/power/charger-manager.c         |  771 +++++++++++++++++++++++++++++++
 include/linux/power/charger-manager.h   |  131 ++++++
 5 files changed, 1062 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/power/charger-manager.txt
 create mode 100644 drivers/power/charger-manager.c
 create mode 100644 include/linux/power/charger-manager.h

diff --git a/Documentation/power/charger-manager.txt b/Documentation/power/charger-manager.txt
new file mode 100644
index 0000000..99630e5
--- /dev/null
+++ b/Documentation/power/charger-manager.txt
@@ -0,0 +1,150 @@
+Charger Manager
+	(C) 2011 MyungJoo Ham <myungjoo.ham@samsung.com>, GPL
+
+Charger Manager provides in-kernel battery charger management that
+requires temperature monitoring during suspend-to-RAM state
+and where each battery may have multiple chargers attached and the userland
+wants to look at the aggregated information of the multiple chargers.
+
+Charger Manager is a platform_driver with power-supply-class entries.
+An instance of Charger Manager (a platform-device created with Charger-Manager)
+represents an independent battery with chargers. If there are multiple
+batteries with their own chargers acting independently in a system,
+the system may need multiple instances of Charger Manager.
+
+1. Introduction
+===============
+
+Charger Manager supports the following:
+
+* Support for multiple chargers (e.g., a device with USB, AC, and solar panels)
+	A system may have multiple chargers (or power sources) and some of
+	they may be activated at the same time. Each charger may have its
+	own power-supply-class and each power-supply-class can provide
+	different information about the battery status. This framework
+	aggregates charger-related information from multiple sources and
+	shows combined information as a single power-supply-class.
+
+* Support for in suspend-to-RAM polling (with suspend_again callback)
+	While the battery is being charged and the system is in suspend-to-RAM,
+	we may need to monitor the battery health by looking at the ambient or
+	battery temperature. We can accomplish this by waking up the system
+	periodically. However, such a method wakes up devices unncessary for
+	monitoring the battery health and tasks, and user processes that are
+	supposed to be kept suspended. That, in turn, incurs unnecessary power
+	consumption and slow down charging process. Or even, such peak power
+	consumption can stop chargers in the middle of charging
+	(external power input < device power consumption), which not
+	only affects the charging time, but the lifespan of the battery.
+
+	Charger Manager provides a function "cm_suspend_again" that can be
+	used as suspend_again callback of platform_suspend_ops. If the platform
+	requires tasks other than cm_suspend_again, it may implement its own
+	suspend_again callback that calls cm_suspend_again in the middle.
+	Normally, the platform will need to resume and suspend some devices
+	that are used by Charger Manager.
+
+2. Global Charger-Manager Data related with suspend_again
+========================================================
+In order to setup Charger Manager with suspend-again feature
+(in-suspend monitoring), the user should provide charger_global_desc
+with setup_charger_manager(struct charger_global_desc *).
+This charger_global_desc data for in-suspend monitoring is global
+as the name suggests. Thus, the user needs to provide only once even
+if there are multiple batteries. If there are multiple batteries, the
+multiple instances of Charger Manager share the same charger_global_desc
+and it will manage in-suspend monitoring for all instances of Charger Manager.
+
+The user needs to provide all the three entries properly in order to activate
+in-suspend monitoring:
+
+struct charger_global_desc {
+
+char *rtc;
+	: The name of rtc (e.g., "rtc0") used to wakeup the system from
+	suspend for Charger Manager. The alarm interrupt (AIE) of the rtc
+	should be able to wake up the system from suspend. Charger Manager
+	saves and restores the alarm value and use the previously-defined
+	alarm if it is going to go off earlier than Charger Manager so that
+	Charger Manager does not interfere with previously-defined alarms.
+
+bool (*is_rtc_only_wakeup_reason)(void);
+	: This callback should let CM know whether
+	the wakeup-from-suspend is caused only by the alarm of "rtc" in the
+	same struct. If there is any other wakeup source triggered the
+	wakeup, it should return false. If the "rtc" is the only wakeup
+	reason, it should return true.
+};
+
+3. How to setup suspend_again
+=============================
+Charger Manager provides a function "extern bool cm_suspend_again(void)".
+When cm_suspend_again is called, it monitors every battery. The suspend_ops
+callback of the system's platform_suspend_ops can call cm_suspend_again
+function to know whether Charger Manager wants to suspend again or not.
+If there are no other devices or tasks that want to use suspend_again
+feature, the platform_suspend_ops may directly refer to cm_suspend_again
+for its suspend_again callback.
+
+The cm_suspend_again() returns true (meaning "I want to suspend again")
+if the system was woken up by Charger Manager and the polling
+(in-suspend monitoring) results in "normal".
+
+4. Charger-Manager Data (struct charger_desc)
+=============================================
+For each battery charged independently from other batteries (if a series of
+batteries are charged by a single charger, they are counted as one independent
+battery), an instance of Charger Manager is attached to it.
+
+struct charger_desc {
+
+enum polling_modes polling_mode;
+	: CM_POLL_DISABLE: do not poll this battery.
+	  CM_POLL_ALWAYS: always poll this battery.
+	  CM_POLL_EXTERNAL_POWER_ONLY: poll this battery if and only if
+				       an external power source is attached.
+	  CM_POLL_CHARGING_ONLY: poll this battery if and only if the
+				 battery is being charged.
+
+unsigned int polling_interval_ms;
+	: Required polling interval in ms. Charger Manager will poll
+	this battery every polling_interval_ms or more frequently.
+
+enum data_source battery_present;
+	CM_FUEL_GAUGE: get battery presence information from fuel gauge.
+	CM_CHARGER_STAT: get battery presence from chargers.
+
+char **psy_charger_stat;
+	: An array ending with NULL that has power-supply-class names of
+	chargers. Each power-supply-class should provide "PRESENT" (if
+	battery_present is "CM_CHARGER_STAT"), "ONLINE" (shows whether an
+	external power source is attached or not), and "STATUS" (shows whether
+	the battery is {"FULL" or not FULL} or {"FULL", "Charging",
+	"Discharging", "NotCharging"}).
+
+int num_charger_regulators;
+struct regulator_bulk_data *charger_regulators;
+	: Regulators representing the chargers in the form for
+	regulator framework's bulk functions.
+
+char *psy_fuel_gauge;
+	: Power-supply-class name of the fuel gauge.
+
+int (*is_temperature_error)(int *mC);
+	: This callback returns 0 if the temperature is safe for charging,
+	a positive number if it is too hot to charge, and a negative number
+	if it is too cold to charge. With the variable mC, the callback returns
+	the temperature in 1/1000 of centigrade.
+};
+
+5. Other Considerations
+=======================
+
+At the charger/battery-related events such as battery-pulled-out,
+charger-pulled-out, charger-inserted, DCIN-over/under-voltage, charger-stopped,
+and others critical to chargers, the system should be configured to wake up.
+At least the following should wake up the system from a suspend:
+a) charger-on/off b) external-power-in/out c) battery-in/out (while charging)
+
+It is usually accomplished by configuring the PMIC as a wakeup source.
+
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 9f88641..92683b5 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -236,6 +236,15 @@ config CHARGER_GPIO
 	  This driver can be build as a module. If so, the module will be
 	  called gpio-charger.
 
+config CHARGER_MANAGER
+        bool "Battery charger manager for multiple chargers"
+        help
+          Say Y to enable charger-manager support, which allows multiple
+          chargers attached to a battery and multiple batteries attached to a
+          system. The charger-manager also can monitor charging status in
+          runtime and in suspend-to-RAM by waking up the system periodically
+          with help of suspend_again support.
+
 config CHARGER_MAX8997
 	tristate "Maxim MAX8997/MAX8966 PMIC battery charger driver"
 	depends on MFD_MAX8997 && REGULATOR_MAX8997
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index b4af13d..d3b24e9 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -36,5 +36,6 @@ obj-$(CONFIG_CHARGER_ISP1704)	+= isp1704_charger.o
 obj-$(CONFIG_CHARGER_MAX8903)	+= max8903_charger.o
 obj-$(CONFIG_CHARGER_TWL4030)	+= twl4030_charger.o
 obj-$(CONFIG_CHARGER_GPIO)	+= gpio-charger.o
+obj-$(CONFIG_CHARGER_MANAGER)	+= charger-manager.o
 obj-$(CONFIG_CHARGER_MAX8997)	+= max8997_charger.o
 obj-$(CONFIG_CHARGER_MAX8998)	+= max8998_charger.o
diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
new file mode 100644
index 0000000..5006756
--- /dev/null
+++ b/drivers/power/charger-manager.c
@@ -0,0 +1,771 @@
+/* linux/drivers/power/charger-manager.c
+ *
+ * Copyright (C) 2011 Samsung Electronics Co., Ltd.
+ * MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This driver enables to monitor battery health and control charger
+ * during suspend-to-mem.
+ * Charger manager depends on other devices. register this later than
+ * the depending devices.
+ *
+ * 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 <linux/io.h>
+#include <linux/module.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/platform_device.h>
+#include <linux/power/charger-manager.h>
+#include <linux/regulator/consumer.h>
+
+/*
+ * Regard CM_JIFFIES_SMALL jiffies is small enough to ignore for
+ * delayed works so that we can run delayed works with CM_JIFFIES_SMALL
+ * without any delays.
+ */
+#define	CM_JIFFIES_SMALL	(2)
+
+/* If y is valid (> 0) and smaller than x, do x = y */
+#define CM_MIN_VALID(x, y)	x = (((y > 0) && ((x) > (y))) ? (y) : (x))
+
+/*
+ * Regard CM_RTC_SMALL (sec) is small enough to ignore error in invoking
+ * rtc alarm. It should be 2 or larger
+ */
+#define CM_RTC_SMALL		(2)
+
+#define UEVENT_BUF_SIZE		32
+
+static LIST_HEAD(cm_list);
+static DEFINE_MUTEX(cm_list_mtx);
+
+/* About in-suspend (suspend-again) monitoring */
+static struct rtc_device *rtc_dev;
+static struct rtc_wkalrm rtc_wkalarm_save; /* Backup RTC alarm */
+static unsigned long rtc_wkalarm_save_; /* 0 if not available */
+static bool cm_suspended;
+static bool cm_rtc_set;
+static unsigned long cm_suspend_duration_ms;
+
+/* Global charger-manager description */
+static struct charger_global_desc *g_desc; /* init with setup_charger_manager */
+
+/**
+ * is_batt_present - See if the battery presents in place.
+ * @cm: the Charger Manager representing the battery.
+ */
+static bool is_batt_present(struct charger_manager *cm)
+{
+	union power_supply_propval val;
+	bool present = false;
+	int i, ret;
+
+	switch (cm->desc->battery_present) {
+	case CM_FUEL_GAUGE:
+		ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
+				POWER_SUPPLY_PROP_PRESENT, &val);
+		if (ret == 0 && val.intval)
+			present = true;
+		break;
+	case CM_CHARGER_STAT:
+		for (i = 0; cm->charger_stat[i]; i++) {
+			ret = cm->charger_stat[i]->get_property(
+					cm->charger_stat[i],
+					POWER_SUPPLY_PROP_PRESENT, &val);
+			if (ret == 0 && val.intval) {
+				present = true;
+				break;
+			}
+		}
+		break;
+	}
+
+	return present;
+}
+
+/**
+ * is_ext_pwr_online - See if an external power source is attached to charge
+ * @cm: the Charger Manager representing the battery.
+ *
+ * Returns true if at least one of the chargers of the battery has an external
+ * power source attached to charge the battery regardless of whether it is
+ * actually charging or not.
+ */
+static bool is_ext_pwr_online(struct charger_manager *cm)
+{
+	union power_supply_propval val;
+	bool online = false;
+	int i, ret;
+
+	/* If at least one of them has one, it's yes. */
+	for (i = 0; cm->charger_stat[i]; i++) {
+		ret = cm->charger_stat[i]->get_property(
+				cm->charger_stat[i],
+				POWER_SUPPLY_PROP_ONLINE, &val);
+		if (ret == 0 && val.intval) {
+			online = true;
+			break;
+		}
+	}
+
+	return online;
+}
+
+/**
+ * is_charging - Returns true if the battery is being charged.
+ * @cm: the Charger Manager representing the battery.
+ */
+static bool is_charging(struct charger_manager *cm)
+{
+	int i, ret;
+	bool charging = false;
+	union power_supply_propval val;
+
+	/* If there is no battery, it cannot be charged */
+	if (!is_batt_present(cm))
+		return false;
+
+	/* If at least one of the charger is charging, return yes */
+	for (i = 0; cm->charger_stat[i]; i++) {
+		/* 1. The charger sholuld not be DISABLED */
+		if (cm->emergency_stop)
+			continue;
+		if (!cm->charger_enabled)
+			continue;
+
+		/* 2. The charger should be online (ext-power) */
+		ret = cm->charger_stat[i]->get_property(
+				cm->charger_stat[i],
+				POWER_SUPPLY_PROP_ONLINE, &val);
+		if (ret) {
+			dev_warn(cm->dev, "Cannot read ONLINE value from %s.\n",
+					cm->desc->psy_charger_stat[i]);
+			continue;
+		}
+		if (val.intval == 0)
+			continue;
+
+		/*
+		 * 3. The charger should not be FULL, DISCHARGING,
+		 * or NOT_CHARGING.
+		 */
+		ret = cm->charger_stat[i]->get_property(
+				cm->charger_stat[i],
+				POWER_SUPPLY_PROP_STATUS, &val);
+		if (ret) {
+			dev_warn(cm->dev, "Cannot read STATUS value from %s.\n",
+					cm->desc->psy_charger_stat[i]);
+			continue;
+		}
+		if (val.intval == POWER_SUPPLY_STATUS_FULL ||
+				val.intval == POWER_SUPPLY_STATUS_DISCHARGING ||
+				val.intval == POWER_SUPPLY_STATUS_NOT_CHARGING)
+			continue;
+
+		/* Then, this is charging. */
+		charging = true;
+		break;
+	}
+
+	return charging;
+}
+
+/**
+ * is_polling_required - Return true if need to continue polling for this CM.
+ * @cm: the Charger Manager representing the battery.
+ */
+static bool is_polling_required(struct charger_manager *cm)
+{
+	switch (cm->desc->polling_mode) {
+	case CM_POLL_DISABLE:
+		return false;
+	case CM_POLL_ALWAYS:
+		return true;
+	case CM_POLL_EXTERNAL_POWER_ONLY:
+		return is_ext_pwr_online(cm);
+	case CM_POLL_CHARGING_ONLY:
+		return is_charging(cm);
+	default:
+		dev_warn(cm->dev, "Incorrect polling_mode (%d)\n",
+			cm->desc->polling_mode);
+	}
+
+	return false;
+}
+
+/**
+ * try_charger_enable - Enable/Disable chargers altogether
+ * @cm: the Charger Manager representing the battery.
+ * @enable: true: enable / false: disable
+ *
+ * Note that Charger Manager keeps the charger enabled regardless whether
+ * the charger is charging or not (because battery is full or no external
+ * power source exists) except when CM needs to disable chargers forcibly
+ * bacause of emergency causes; when the battery is overheated or too cold.
+ */
+static int try_charger_enable(struct charger_manager *cm, bool enable)
+{
+	int err = 0, i;
+	struct charger_desc *desc = cm->desc;
+
+	/* Ignore if it's redundent command */
+	if (enable && cm->charger_enabled)
+		return 0;
+	if (!enable && !cm->charger_enabled)
+		return 0;
+
+	if (enable) {
+		if (cm->emergency_stop)
+			return -EAGAIN;
+		err = regulator_bulk_enable(desc->num_charger_regulators,
+					desc->charger_regulators);
+	} else {
+		/*
+		 * Abnormal battery state - Stop charging forcibly,
+		 * even if charger was enabled at the other places
+		 */
+		err = regulator_bulk_disable(desc->num_charger_regulators,
+					desc->charger_regulators);
+
+		for (i = 0; i < desc->num_charger_regulators; i++) {
+			if (regulator_is_enabled(
+				    desc->charger_regulators[i].consumer)) {
+				regulator_force_disable(
+					desc->charger_regulators[i].consumer);
+				dev_warn(cm->dev,
+					"Disable regulator(%s) forcibly.\n",
+					desc->charger_regulators[i].supply);
+			}
+		}
+	}
+
+	if (!err)
+		cm->charger_enabled = enable;
+
+	return err;
+}
+
+/**
+ * uevent_notify - Let users know something has changed.
+ * @cm: the Charger Manager representing the battery.
+ * @event: the event string.
+ *
+ * If @event is null, it implies that uevent_notify is called
+ * by resume function. When called in the resume function, cm_suspended
+ * should be already reset to false in order to let uevent_notify
+ * notify the recent event during the suspend to users. While
+ * suspended, uevent_notify does not notify users, but tracks
+ * events so that uevent_notify can notify users later after resumed.
+ */
+static void uevent_notify(struct charger_manager *cm, const char *event)
+{
+	static char env_str[UEVENT_BUF_SIZE + 1] = "";
+	static char env_str_save[UEVENT_BUF_SIZE + 1] = "";
+
+	if (cm_suspended) {
+		/* Nothing in suspended-event buffer */
+		if (env_str_save[0] == 0) {
+			if (!strncmp(env_str, event, UEVENT_BUF_SIZE))
+				return; /* status not changed */
+			strncpy(env_str_save, event, UEVENT_BUF_SIZE);
+			return;
+		}
+
+		if (!strncmp(env_str_save, event, UEVENT_BUF_SIZE))
+			return; /* Duplicated. */
+		else
+			strncpy(env_str_save, event, UEVENT_BUF_SIZE);
+
+		return;
+	}
+
+	if (event == NULL) {
+		/* No messages pending */
+		if (!env_str_save[0])
+			return;
+
+		strncpy(env_str, env_str_save, UEVENT_BUF_SIZE);
+		kobject_uevent(&cm->dev->kobj, KOBJ_CHANGE);
+		env_str_save[0] = 0;
+
+		return;
+	}
+
+	/* status not changed */
+	if (!strncmp(env_str, event, UEVENT_BUF_SIZE))
+		return;
+
+	/* save the status and notify the update */
+	strncpy(env_str, event, UEVENT_BUF_SIZE);
+	kobject_uevent(&cm->dev->kobj, KOBJ_CHANGE);
+
+	dev_info(cm->dev, event);
+}
+
+/**
+ * _cm_monitor - Monitor the temperature and return true for exceptions.
+ * @cm: the Charger Manager representing the battery.
+ *
+ * Returns true if there is an event to notify for the battery.
+ * (True if the status of "emergency_stop" changes)
+ */
+static bool _cm_monitor(struct charger_manager *cm)
+{
+	struct charger_desc *desc = cm->desc;
+	int temp = desc->is_temperature_error(&cm->last_temp_mC);
+
+	dev_dbg(cm->dev, "monitoring (%2.2d.%3.3dC)\n",
+		cm->last_temp_mC / 1000, cm->last_temp_mC % 1000);
+
+	/* It has been stopped already */
+	if (temp && cm->emergency_stop)
+		return false;
+
+	/* It has been charging already */
+	if (!temp && !cm->emergency_stop)
+		return false;
+
+	if (temp) {
+		cm->emergency_stop = temp;
+		if (!try_charger_enable(cm, false)) {
+			if (temp > 0)
+				uevent_notify(cm, "OVERHEAT");
+			else
+				uevent_notify(cm, "COLD");
+		}
+	} else {
+		cm->emergency_stop = 0;
+		if (!try_charger_enable(cm, true))
+			uevent_notify(cm, "CHARGING");
+	}
+
+	return true;
+}
+
+/**
+ * cm_monitor - Monitor every battery.
+ *
+ * Returns true if there is an event to notify from any of the batteries.
+ * (True if the status of "emergency_stop" changes)
+ */
+static bool cm_monitor(void)
+{
+	bool stop = false;
+	struct charger_manager *cm;
+
+	mutex_lock(&cm_list_mtx);
+
+	list_for_each_entry(cm, &cm_list, entry)
+		stop |= _cm_monitor(cm);
+
+	mutex_unlock(&cm_list_mtx);
+
+	return stop;
+}
+
+/**
+ * cm_setup_timer - For in-suspend monitoring setup wakeup alarm
+ *		    for suspend_again.
+ *
+ * Returns true if the alarm is set for Charger Manager to use.
+ * Returns false if
+ *	cm_setup_timer fails to set an alarm,
+ *	cm_setup_timer does not need to set an alarm for Charger Manager,
+ *	or an alarm previously configured is to be used.
+ */
+static bool cm_setup_timer(void)
+{
+	struct charger_manager *cm;
+	unsigned int wakeup_ms = UINT_MAX;
+	bool ret = false;
+
+	mutex_lock(&cm_list_mtx);
+
+	list_for_each_entry(cm, &cm_list, entry) {
+		/* Skip if polling is not required for this CM */
+		if (!is_polling_required(cm) && !cm->emergency_stop)
+			continue;
+		if (cm->desc->polling_interval_ms == 0)
+			continue;
+		CM_MIN_VALID(wakeup_ms, cm->desc->polling_interval_ms);
+	}
+
+	mutex_unlock(&cm_list_mtx);
+
+	if (wakeup_ms < UINT_MAX && wakeup_ms > 0) {
+		pr_info("Charger Manager wakeup timer: %u ms.\n", wakeup_ms);
+		if (rtc_dev) {
+			struct rtc_wkalrm tmp;
+			unsigned long time, now;
+			unsigned long add = DIV_ROUND_UP(wakeup_ms, 1000);
+
+			/*
+			 * Set alarm with the polling interval (wakeup_ms)
+			 * except when rtc_wkalarm_save comes first.
+			 * However, the alarm time should be NOW +
+			 * CM_RTC_SMALL or later.
+			 */
+			tmp.enabled = 1;
+			rtc_read_time(rtc_dev, &tmp.time);
+			rtc_tm_to_time(&tmp.time, &now);
+			if (add < CM_RTC_SMALL)
+				add = CM_RTC_SMALL;
+			time = now + add;
+
+			ret = true;
+
+			if (rtc_wkalarm_save.enabled && rtc_wkalarm_save_ &&
+			    rtc_wkalarm_save_ < time) {
+				if (rtc_wkalarm_save_ < now + CM_RTC_SMALL)
+					time = now + CM_RTC_SMALL;
+				else
+					time = rtc_wkalarm_save_;
+
+				/* The timer is not appointed by CM */
+				ret = false;
+			}
+
+			pr_info("Waking up after %lu secs.\n",
+					time - now);
+
+			rtc_time_to_tm(time, &tmp.time);
+			rtc_set_alarm(rtc_dev, &tmp);
+			cm_suspend_duration_ms += wakeup_ms;
+			return ret;
+		}
+	}
+
+	if (rtc_dev)
+		rtc_set_alarm(rtc_dev, &rtc_wkalarm_save);
+	return false;
+}
+
+/**
+ * cm_suspend_again - Determine whether suspend again or not
+ *
+ * Returns true if the system should be suspended again
+ * Returns false if the system should be woken up
+ */
+bool cm_suspend_again(void)
+{
+	struct charger_manager *cm;
+	bool ret = false;
+
+	if (!g_desc)
+		return false;
+	if (!g_desc->is_rtc_only_wakeup_reason)
+		return false;
+	if (!g_desc->is_rtc_only_wakeup_reason())
+		return false;
+	if (!cm_rtc_set)
+		return false;
+
+	if (cm_monitor())
+		goto out;
+
+	ret = true;
+	mutex_lock(&cm_list_mtx);
+	list_for_each_entry(cm, &cm_list, entry) {
+		if (cm->status_save_ext_pwr_inserted != is_ext_pwr_online(cm) ||
+		    cm->status_save_batt != is_batt_present(cm))
+			ret = false;
+	}
+	mutex_unlock(&cm_list_mtx);
+
+	cm_rtc_set = cm_setup_timer();
+out:
+	/* It's about the time when the non-CM appointed timer goes off */
+	if (rtc_wkalarm_save.enabled) {
+		unsigned long now;
+		struct rtc_time tmp;
+
+		rtc_read_time(rtc_dev, &tmp);
+		rtc_tm_to_time(&tmp, &now);
+
+		if (rtc_wkalarm_save_ &&
+		    now + CM_RTC_SMALL >= rtc_wkalarm_save_)
+			return false;
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cm_suspend_again);
+
+/**
+ * setup_charger_manager - initialize charger_global_desc data
+ * @gd: pointer to instance of charger_global_desc
+ */
+int setup_charger_manager(struct charger_global_desc *gd)
+{
+	if (!gd)
+		return -EINVAL;
+
+	if (rtc_dev)
+		rtc_class_close(rtc_dev);
+	rtc_dev = NULL;
+	g_desc = NULL;
+
+	if (!gd->is_rtc_only_wakeup_reason) {
+		pr_err("The callback is_wktimer_only_wkreason is not given.\n");
+		return -EINVAL;
+	}
+
+	if (gd->rtc) {
+		rtc_dev = rtc_class_open(gd->rtc);
+		if (IS_ERR_OR_NULL(rtc_dev)) {
+			rtc_dev = NULL;
+			/* Retry at probe. RTC may be not registered yet */
+		}
+	} else {
+		pr_warn("No wktimer is given for charger manager."
+			"In-suspend monitoring won't work.\n");
+	}
+
+	g_desc = gd;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(setup_charger_manager);
+
+static int charger_manager_probe(struct platform_device *pdev)
+{
+	struct charger_desc *desc = dev_get_platdata(&pdev->dev);
+	struct charger_manager *cm;
+	int ret = 0, i;
+
+	if (g_desc && !rtc_dev && g_desc->rtc) {
+		rtc_dev = rtc_class_open(g_desc->rtc);
+		if (IS_ERR_OR_NULL(rtc_dev)) {
+			rtc_dev = NULL;
+			dev_err(&pdev->dev, "Cannot get RTC %s.\n",
+				g_desc->rtc);
+			ret = -ENODEV;
+			goto err_alloc;
+		}
+	}
+
+	if (!desc) {
+		dev_err(&pdev->dev, "No platform data (desc) found.\n");
+		ret = -ENODEV;
+		goto err_alloc;
+	}
+
+	cm = kzalloc(sizeof(struct charger_manager), GFP_KERNEL);
+	if (!cm) {
+		dev_err(&pdev->dev, "Cannot allocate memory.\n");
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	/* Basic Values. Unspecified are Null or 0 */
+	cm->dev = &pdev->dev;
+	cm->desc = desc;
+	cm->last_temp_mC = INT_MIN; /* denotes "unmeasured, yet" */
+
+	if (!desc->charger_regulators || desc->num_charger_regulators < 1) {
+		ret = -EINVAL;
+		dev_err(&pdev->dev, "charger_regulators undefined.\n");
+		goto err_no_charger;
+	}
+
+	ret = regulator_bulk_get(&pdev->dev, desc->num_charger_regulators,
+				 desc->charger_regulators);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot get charger regulators.\n");
+		goto err_no_charger;
+	}
+
+	if (!desc->psy_charger_stat || !desc->psy_charger_stat[0]) {
+		dev_err(&pdev->dev, "No power supply defined.\n");
+		ret = -EINVAL;
+		goto err_no_charger_stat;
+	}
+
+	for (i = 0; desc->psy_charger_stat[i]; i++)
+		/* Counting index only */ ;
+
+	cm->charger_stat = kzalloc(sizeof(struct power_supply *) * (i + 1),
+				   GFP_KERNEL);
+	if (!cm->charger_stat) {
+		ret = -ENOMEM;
+		goto err_no_charger_stat;
+	}
+
+	for (i = 0; desc->psy_charger_stat[i]; i++) {
+		cm->charger_stat[i] = power_supply_get_by_name(
+					desc->psy_charger_stat[i]);
+		if (!cm->charger_stat[i]) {
+			dev_err(&pdev->dev, "Cannot find power supply "
+					"\"%s\"\n",
+					desc->psy_charger_stat[i]);
+			ret = -ENODEV;
+			goto err_chg_stat;
+		}
+	}
+
+	cm->fuel_gauge = power_supply_get_by_name(desc->psy_fuel_gauge);
+	if (!cm->fuel_gauge) {
+		dev_err(&pdev->dev, "Cannot find power supply \"%s\"\n",
+				desc->psy_fuel_gauge);
+		ret = -ENODEV;
+		goto err_chg_stat;
+	}
+
+	if (desc->polling_interval_ms == 0 ||
+	    msecs_to_jiffies(desc->polling_interval_ms) <= CM_JIFFIES_SMALL) {
+		dev_err(&pdev->dev, "polling_interval_ms is too small\n");
+		ret = -EINVAL;
+		goto err_chg_stat;
+	}
+
+	if (!desc->is_temperature_error) {
+		dev_err(&pdev->dev, "there is no is_temperature_error\n");
+		ret = -EINVAL;
+		goto err_chg_stat;
+	}
+
+	platform_set_drvdata(pdev, cm);
+
+	ret = try_charger_enable(cm, true);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot enable charger regulators\n");
+		goto err_chg_stat;
+	}
+
+	/* Add to the list */
+	mutex_lock(&cm_list_mtx);
+	list_add(&cm->entry, &cm_list);
+	mutex_unlock(&cm_list_mtx);
+
+	return 0;
+
+err_chg_stat:
+	kfree(cm->charger_stat);
+err_no_charger_stat:
+	if (desc->charger_regulators)
+		regulator_bulk_free(desc->num_charger_regulators,
+					desc->charger_regulators);
+err_no_charger:
+	kfree(cm);
+err_alloc:
+	return ret;
+}
+
+static int __devexit charger_manager_remove(struct platform_device *pdev)
+{
+	struct charger_manager *cm = platform_get_drvdata(pdev);
+	struct charger_desc *desc = cm->desc;
+
+	/* Remove from the list */
+	mutex_lock(&cm_list_mtx);
+	list_del(&cm->entry);
+	mutex_unlock(&cm_list_mtx);
+
+	kfree(cm->charger_stat);
+	if (desc->charger_regulators)
+		regulator_bulk_free(desc->num_charger_regulators,
+					desc->charger_regulators);
+	kfree(cm);
+	return 0;
+}
+
+const struct platform_device_id charger_manager_id[] = {
+	{ "charger-manager", 0 },
+	{ },
+};
+
+static int cm_suspend_prepare(struct device *dev)
+{
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct charger_manager *cm = platform_get_drvdata(pdev);
+
+	if (!cm_suspended) {
+		if (rtc_dev) {
+			struct rtc_time tmp;
+			unsigned long now;
+
+			rtc_read_alarm(rtc_dev, &rtc_wkalarm_save);
+			rtc_read_time(rtc_dev, &tmp);
+
+			if (rtc_wkalarm_save.enabled) {
+				rtc_tm_to_time(&rtc_wkalarm_save.time,
+					       &rtc_wkalarm_save_);
+				rtc_tm_to_time(&tmp, &now);
+				if (now > rtc_wkalarm_save_)
+					rtc_wkalarm_save_ = 0;
+			} else {
+				rtc_wkalarm_save_ = 0;
+			}
+		}
+		cm_suspended = true;
+	}
+
+	cm->status_save_ext_pwr_inserted = is_ext_pwr_online(cm);
+	cm->status_save_batt = is_batt_present(cm);
+
+	if (!cm_rtc_set) {
+		cm_suspend_duration_ms = 0;
+		cm_rtc_set = cm_setup_timer();
+	}
+
+	return 0;
+}
+
+static void cm_suspend_complete(struct device *dev)
+{
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct charger_manager *cm = platform_get_drvdata(pdev);
+
+	if (cm_suspended) {
+		if (rtc_dev) {
+			struct rtc_wkalrm tmp;
+
+			rtc_read_alarm(rtc_dev, &tmp);
+			rtc_wkalarm_save.pending = tmp.pending;
+			rtc_set_alarm(rtc_dev, &rtc_wkalarm_save);
+		}
+		cm_suspended = false;
+		cm_rtc_set = false;
+	}
+
+	uevent_notify(cm, NULL);
+}
+
+static const struct dev_pm_ops charger_manager_pm = {
+	.prepare	= cm_suspend_prepare,
+	.complete	= cm_suspend_complete,
+};
+
+static struct platform_driver charger_manager_driver = {
+	.driver = {
+		.name = "charger-manager",
+		.owner = THIS_MODULE,
+		.pm = &charger_manager_pm,
+	},
+	.probe = charger_manager_probe,
+	.remove = __devexit_p(charger_manager_remove),
+	.id_table = charger_manager_id,
+};
+
+static int __init charger_manager_init(void)
+{
+	return platform_driver_register(&charger_manager_driver);
+}
+late_initcall(charger_manager_init);
+
+static void __exit charger_manager_cleanup(void)
+{
+	platform_driver_unregister(&charger_manager_driver);
+}
+module_exit(charger_manager_cleanup);
+
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_DESCRIPTION("Charger Manager");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("charger-manager");
diff --git a/include/linux/power/charger-manager.h b/include/linux/power/charger-manager.h
new file mode 100644
index 0000000..c91e208
--- /dev/null
+++ b/include/linux/power/charger-manager.h
@@ -0,0 +1,131 @@
+/* linux/include/linux/power/charger-manager.h
+ *
+ * Copyright (C) 2011 Samsung Electronics Co., Ltd.
+ * MyungJoo.Ham <myungjoo.ham@samsung.com>
+ *
+ * Charger Manager.
+ * This framework enables to control and multiple chargers and to
+ * monitor charging even in the context of suspend-to-RAM with
+ * an interface combining the chargers.
+ *
+ * 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.
+**/
+
+#ifndef _CHARGER_MANAGER_H
+#define _CHARGER_MANAGER_H
+
+#include <linux/power_supply.h>
+
+enum data_source {
+	CM_FUEL_GAUGE,
+	CM_CHARGER_STAT,
+};
+
+enum polling_modes {
+	CM_POLL_DISABLE = 0,
+	CM_POLL_ALWAYS,
+	CM_POLL_EXTERNAL_POWER_ONLY,
+	CM_POLL_CHARGING_ONLY,
+};
+
+/**
+ * struct charger_global_desc
+ * @rtc: the name of RTC used to wake up the system from suspend.
+ * @is_rtc_only_wakeup_reason:
+ *	If the system is woken up by waekup-sources other than the RTC or
+ *	callbacks, Charger Manager should recognize with
+ *	is_rtc_only_wakeup_reason() returning false.
+ *	If the RTC given to CM is the only wakeup reason,
+ *	is_rtc_only_wakeup_reason should return true.
+ */
+struct charger_global_desc {
+	char *rtc;
+
+	bool (*is_rtc_only_wakeup_reason)(void);
+};
+
+/**
+ * struct charger_desc
+ * @polling_mode:
+ *	Determine which polling mode will be used
+ * @polling_interval_ms: interval in millisecond at which
+ *	charger manager will monitor battery health
+ * @battery_present:
+ *	Specify where information for existance of battery can be obtained
+ * @psy_charger_stat: the names of power-supply for chargers
+ * @num_charger_regulator: the number of entries in charger_regulators
+ * @charger_regulators: array of regulator_bulk_data for chargers
+ * @psy_fuel_gauge: the name of power-supply for fuel gauge
+ * @is_temperature_error:
+ *	Determine whether the status is overheat or cold or normal.
+ *	return_value > 0: overheat
+ *	return_value == 0: normal
+ *	return_value < 0: cold
+ */
+struct charger_desc {
+	enum polling_modes polling_mode;
+	unsigned int polling_interval_ms;
+
+	enum data_source battery_present;
+
+	char **psy_charger_stat;
+
+	int num_charger_regulators;
+	struct regulator_bulk_data *charger_regulators;
+
+	char *psy_fuel_gauge;
+
+	int (*is_temperature_error)(int *mC);
+};
+
+#define PSY_NAME_MAX	30
+
+/**
+ * struct charger_manager
+ * @entry: entry for list
+ * @dev: device pointer
+ * @desc: instance of charger_desc
+ * @fuel_gauge: power_supply for fuel gauge
+ * @charger_stat: array of power_supply for chargers
+ * @charger_enabled: the state of charger
+ * @emergency_stop:
+ *	When setting true, stop charging
+ * @last_temp_mC: the measured temperature in milli-Celsius
+ * @status_save_ext_pwr_inserted:
+ *	saved status of external power before entering suspend-to-RAM
+ * @status_save_batt:
+ *	saved status of battery before entering suspend-to-RAM
+ */
+struct charger_manager {
+	struct list_head entry;
+	struct device *dev;
+	struct charger_desc *desc;
+
+	struct power_supply *fuel_gauge;
+	struct power_supply **charger_stat;
+
+	bool charger_enabled;
+
+	int emergency_stop;
+	int last_temp_mC;
+
+	bool status_save_ext_pwr_inserted;
+	bool status_save_batt;
+};
+
+#ifdef CONFIG_CHARGER_MANAGER
+extern int setup_charger_manager(struct charger_global_desc *gd);
+extern bool cm_suspend_again(void);
+#else
+static void __maybe_unused setup_charger_manager(struct charger_global_desc *gd)
+{ }
+
+static bool __maybe_unused cm_suspend_again(void)
+{
+	return false;
+}
+#endif
+
+#endif /* _CHARGER_MANAGER_H */
-- 
1.7.4.1

[PATCH v2 2/2] power: Charger-Manager: add properties for power-supply-class

[Donggeun Kim]

Charger Manager provides power-supply-class aggregating
information from multiple chargers and a fuel-gauge.

Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 Documentation/power/charger-manager.txt |   14 ++
 drivers/power/charger-manager.c         |  295 ++++++++++++++++++++++++++++++-
 include/linux/power/charger-manager.h   |   17 ++
 3 files changed, 325 insertions(+), 1 deletions(-)

diff --git a/Documentation/power/charger-manager.txt b/Documentation/power/charger-manager.txt
index 99630e5..3a55c79 100644
--- a/Documentation/power/charger-manager.txt
+++ b/Documentation/power/charger-manager.txt
@@ -98,6 +98,11 @@ battery), an instance of Charger Manager is attached to it.
 
 struct charger_desc {
 
+char *psy_name;
+	: The power-supply-class name of the battery. Default is
+	"battery" if psy_name is NULL. Users can access the psy entries
+	at "/sys/class/power_supply/[psy_name]/".
+
 enum polling_modes polling_mode;
 	: CM_POLL_DISABLE: do not poll this battery.
 	  CM_POLL_ALWAYS: always poll this battery.
@@ -106,6 +111,12 @@ enum polling_modes polling_mode;
 	  CM_POLL_CHARGING_ONLY: poll this battery if and only if the
 				 battery is being charged.
 
+unsigned int fullbatt_uV;
+	: If specified with a non-zero value, Charger Manager assumes
+	that the battery is full (capacity = 100) if the battery is not being
+	charged and the battery voltage is equal to or greater than
+	fullbatt_uV.
+
 unsigned int polling_interval_ms;
 	: Required polling interval in ms. Charger Manager will poll
 	this battery every polling_interval_ms or more frequently.
@@ -131,10 +142,13 @@ char *psy_fuel_gauge;
 	: Power-supply-class name of the fuel gauge.
 
 int (*is_temperature_error)(int *mC);
+bool measure_battery_temp;
 	: This callback returns 0 if the temperature is safe for charging,
 	a positive number if it is too hot to charge, and a negative number
 	if it is too cold to charge. With the variable mC, the callback returns
 	the temperature in 1/1000 of centigrade.
+	The source of temperature can be battery or ambient one according to
+	the value of measure_battery_temp.
 };
 
 5. Other Considerations
diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
index 5006756..818f890 100644
--- a/drivers/power/charger-manager.c
+++ b/drivers/power/charger-manager.c
@@ -118,6 +118,32 @@ static bool is_ext_pwr_online(struct charger_manager *cm)
 }
 
 /**
+ * get_batt_uV - Get the voltage level of the battery
+ * @cm: the Charger Manager representing the battery.
+ * @uV: the voltage level returned.
+ *
+ * Returns 0 if there is no error.
+ * Returns a negative value on error.
+ */
+static int get_batt_uV(struct charger_manager *cm, int *uV)
+{
+	union power_supply_propval val;
+	int ret;
+
+	if (cm->fuel_gauge)
+		ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
+				POWER_SUPPLY_PROP_VOLTAGE_NOW, &val);
+	else
+		return -ENODEV;
+
+	if (ret)
+		return ret;
+
+	*uV = val.intval;
+	return 0;
+}
+
+/**
  * is_charging - Returns true if the battery is being charged.
  * @cm: the Charger Manager representing the battery.
  */
@@ -369,6 +395,208 @@ static bool cm_monitor(void)
 	return stop;
 }
 
+static int charger_get_property(struct power_supply *psy,
+		enum power_supply_property psp,
+		union power_supply_propval *val)
+{
+	struct charger_manager *cm = container_of(psy,
+			struct charger_manager, charger_psy);
+	struct charger_desc *desc = cm->desc;
+	int i, ret = 0, uV;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		if (is_charging(cm))
+			val->intval = POWER_SUPPLY_STATUS_CHARGING;
+		else if (is_ext_pwr_online(cm))
+			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		else
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		break;
+	case POWER_SUPPLY_PROP_HEALTH:
+		if (cm->emergency_stop > 0)
+			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
+		else if (cm->emergency_stop < 0)
+			val->intval = POWER_SUPPLY_HEALTH_COLD;
+		else
+			val->intval = POWER_SUPPLY_HEALTH_GOOD;
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		if (is_batt_present(cm))
+			val->intval = 1;
+		else
+			val->intval = 0;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = get_batt_uV(cm, &i);
+		val->intval = i;
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
+				POWER_SUPPLY_PROP_CURRENT_NOW, val);
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		/* in thenth of centigrade */
+		if (cm->last_temp_mC == INT_MIN)
+			desc->is_temperature_error(&cm->last_temp_mC);
+		val->intval = cm->last_temp_mC / 100;
+		if (!desc->measure_battery_temp)
+			ret = -ENODEV;
+		break;
+	case POWER_SUPPLY_PROP_TEMP_AMBIENT:
+		/* in thenth of centigrade */
+		if (cm->last_temp_mC == INT_MIN)
+			desc->is_temperature_error(&cm->last_temp_mC);
+		val->intval = cm->last_temp_mC / 100;
+		if (desc->measure_battery_temp)
+			ret = -ENODEV;
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		if (!cm->fuel_gauge) {
+			ret = -ENODEV;
+			break;
+		}
+
+		if (!is_batt_present(cm)) {
+			/* There is no battery. Assume 100% */
+			val->intval = 100;
+			break;
+		}
+
+		ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
+					POWER_SUPPLY_PROP_CAPACITY, val);
+		if (ret)
+			break;
+
+		if (val->intval > 100) {
+			val->intval = 100;
+			break;
+		}
+		if (val->intval < 0)
+			val->intval = 0;
+
+		/* Do not adjust SOC when charging: voltage is overrated */
+		if (is_charging(cm))
+			break;
+
+		/*
+		 * If the capacity value is inconsistent, calibrate it base on
+		 * the battery voltage values and the thresholds given as desc
+		 */
+		ret = get_batt_uV(cm, &uV);
+		if (ret) {
+			/* Voltage information not available. No calibration */
+			ret = 0;
+			break;
+		}
+
+		if (desc->fullbatt_uV > 0 && uV >= desc->fullbatt_uV &&
+		    !is_charging(cm)) {
+			val->intval = 100;
+			break;
+		}
+
+		break;
+	case POWER_SUPPLY_PROP_ONLINE:
+		if (is_ext_pwr_online(cm))
+			val->intval = 1;
+		else
+			val->intval = 0;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+		if (cm->fuel_gauge) {
+			if (cm->fuel_gauge->get_property(cm->fuel_gauge,
+			    POWER_SUPPLY_PROP_CHARGE_FULL, val) == 0)
+				break;
+		}
+
+		if (is_ext_pwr_online(cm)) {
+			/* Not full if it's charging. */
+			if (is_charging(cm)) {
+				val->intval = 0;
+				break;
+			}
+			/*
+			 * Full if it's powered but not charging andi
+			 * not forced stop by emergency
+			 */
+			if (!cm->emergency_stop) {
+				val->intval = 1;
+				break;
+			}
+		}
+
+		/* Full if it's over the fullbatt voltage */
+		ret = get_batt_uV(cm, &uV);
+		if (!ret && desc->fullbatt_uV > 0 && uV >= desc->fullbatt_uV &&
+		    !is_charging(cm)) {
+			val->intval = 1;
+			break;
+		}
+
+		/* Full if the cap is 100 */
+		if (cm->fuel_gauge) {
+			ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
+					POWER_SUPPLY_PROP_CAPACITY, val);
+			if (!ret && val->intval >= 100 && !is_charging(cm)) {
+				val->intval = 1;
+				break;
+			}
+		}
+
+		val->intval = 0;
+		ret = 0;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+		if (is_charging(cm)) {
+			ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
+						POWER_SUPPLY_PROP_CHARGE_NOW,
+						val);
+			if (ret) {
+				val->intval = 1;
+				ret = 0;
+			} else {
+				/* If CHARGE_NOW is supplied, use it */
+				val->intval = (val->intval > 0) ?
+						val->intval : 1;
+			}
+		} else {
+			val->intval = 0;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+	return ret;
+}
+
+#define NUM_CHARGER_PSY_OPTIONAL	(4)
+static enum power_supply_property default_charger_props[] = {
+	/* Guaranteed to provide */
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_CHARGE_FULL,
+	/*
+	 * Optional properties are:
+	 * POWER_SUPPLY_PROP_CHARGE_NOW,
+	 * POWER_SUPPLY_PROP_CURRENT_NOW,
+	 * POWER_SUPPLY_PROP_TEMP, and
+	 * POWER_SUPPLY_PROP_TEMP_AMBIENT,
+	 */
+};
+
+static struct power_supply psy_default = {
+	.name = "battery",
+	.type = POWER_SUPPLY_TYPE_BATTERY,
+	.properties = default_charger_props,
+	.num_properties = ARRAY_SIZE(default_charger_props),
+	.get_property = charger_get_property,
+};
+
 /**
  * cm_setup_timer - For in-suspend monitoring setup wakeup alarm
  *		    for suspend_again.
@@ -536,6 +764,7 @@ static int charger_manager_probe(struct platform_device *pdev)
 	struct charger_desc *desc = dev_get_platdata(&pdev->dev);
 	struct charger_manager *cm;
 	int ret = 0, i;
+	union power_supply_propval val;
 
 	if (g_desc && !rtc_dev && g_desc->rtc) {
 		rtc_dev = rtc_class_open(g_desc->rtc);
@@ -630,10 +859,67 @@ static int charger_manager_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, cm);
 
+	memcpy(&cm->charger_psy, &psy_default,
+				sizeof(psy_default));
+	if (!desc->psy_name) {
+		strncpy(cm->psy_name_buf, psy_default.name,
+				PSY_NAME_MAX);
+	} else {
+		strncpy(cm->psy_name_buf, desc->psy_name, PSY_NAME_MAX);
+	}
+	cm->charger_psy.name = cm->psy_name_buf;
+
+	/* Allocate for psy properties because they may vary */
+	cm->charger_psy.properties = kzalloc(sizeof(enum power_supply_property)
+				* (ARRAY_SIZE(default_charger_props) +
+				NUM_CHARGER_PSY_OPTIONAL),
+				GFP_KERNEL);
+	if (!cm->charger_psy.properties) {
+		dev_err(&pdev->dev, "Cannot allocate for psy properties.\n");
+		ret = -ENOMEM;
+		goto err_chg_stat;
+	}
+	memcpy(cm->charger_psy.properties, default_charger_props,
+		sizeof(enum power_supply_property) *
+		ARRAY_SIZE(default_charger_props));
+	cm->charger_psy.num_properties = psy_default.num_properties;
+
+	/* Find which optional psy-properties are available */
+	if (!cm->fuel_gauge->get_property(cm->fuel_gauge,
+					  POWER_SUPPLY_PROP_CHARGE_NOW, &val)) {
+		cm->charger_psy.properties[cm->charger_psy.num_properties] =
+				POWER_SUPPLY_PROP_CHARGE_NOW;
+		cm->charger_psy.num_properties++;
+	}
+	if (!cm->fuel_gauge->get_property(cm->fuel_gauge,
+					  POWER_SUPPLY_PROP_CURRENT_NOW,
+					  &val)) {
+		cm->charger_psy.properties[cm->charger_psy.num_properties] =
+				POWER_SUPPLY_PROP_CURRENT_NOW;
+		cm->charger_psy.num_properties++;
+	}
+	if (!desc->measure_battery_temp) {
+		cm->charger_psy.properties[cm->charger_psy.num_properties] =
+				POWER_SUPPLY_PROP_TEMP_AMBIENT;
+		cm->charger_psy.num_properties++;
+	}
+	if (desc->measure_battery_temp) {
+		cm->charger_psy.properties[cm->charger_psy.num_properties] =
+				POWER_SUPPLY_PROP_TEMP;
+		cm->charger_psy.num_properties++;
+	}
+
+	ret = power_supply_register(NULL, &cm->charger_psy);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot register charger-manager with"
+				" name \"%s\".\n", cm->charger_psy.name);
+		goto err_register;
+	}
+
 	ret = try_charger_enable(cm, true);
 	if (ret) {
 		dev_err(&pdev->dev, "Cannot enable charger regulators\n");
-		goto err_chg_stat;
+		goto err_enable;
 	}
 
 	/* Add to the list */
@@ -643,6 +929,10 @@ static int charger_manager_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_enable:
+	power_supply_unregister(&cm->charger_psy);
+err_register:
+	kfree(cm->charger_psy.properties);
 err_chg_stat:
 	kfree(cm->charger_stat);
 err_no_charger_stat:
@@ -665,6 +955,9 @@ static int __devexit charger_manager_remove(struct platform_device *pdev)
 	list_del(&cm->entry);
 	mutex_unlock(&cm_list_mtx);
 
+	power_supply_unregister(&cm->charger_psy);
+
+	kfree(cm->charger_psy.properties);
 	kfree(cm->charger_stat);
 	if (desc->charger_regulators)
 		regulator_bulk_free(desc->num_charger_regulators,
diff --git a/include/linux/power/charger-manager.h b/include/linux/power/charger-manager.h
index c91e208..3bc0e34 100644
--- a/include/linux/power/charger-manager.h
+++ b/include/linux/power/charger-manager.h
@@ -48,8 +48,12 @@ struct charger_global_desc {
 
 /**
  * struct charger_desc
+ * @psy_name: the name of power-supply-class for charger manager
  * @polling_mode:
  *	Determine which polling mode will be used
+ * @fullbatt_uV: voltage in microvolt
+ *	If it is not being charged and VBATT >= fullbatt_uV,
+ *	it is assumed to be full.
  * @polling_interval_ms: interval in millisecond at which
  *	charger manager will monitor battery health
  * @battery_present:
@@ -63,11 +67,18 @@ struct charger_global_desc {
  *	return_value > 0: overheat
  *	return_value == 0: normal
  *	return_value < 0: cold
+ * @measure_battery_temp:
+ *	true: measure battery temperature
+ *	false: measure ambient temperature
  */
 struct charger_desc {
+	char *psy_name;
+
 	enum polling_modes polling_mode;
 	unsigned int polling_interval_ms;
 
+	unsigned int fullbatt_uV;
+
 	enum data_source battery_present;
 
 	char **psy_charger_stat;
@@ -78,6 +89,7 @@ struct charger_desc {
 	char *psy_fuel_gauge;
 
 	int (*is_temperature_error)(int *mC);
+	bool measure_battery_temp;
 };
 
 #define PSY_NAME_MAX	30
@@ -93,6 +105,8 @@ struct charger_desc {
  * @emergency_stop:
  *	When setting true, stop charging
  * @last_temp_mC: the measured temperature in milli-Celsius
+ * @psy_name_buf: the name of power-supply-class for charger manager
+ * @charger_psy: power_supply for charger manager
  * @status_save_ext_pwr_inserted:
  *	saved status of external power before entering suspend-to-RAM
  * @status_save_batt:
@@ -111,6 +125,9 @@ struct charger_manager {
 	int emergency_stop;
 	int last_temp_mC;
 
+	char psy_name_buf[PSY_NAME_MAX + 1];
+	struct power_supply charger_psy;
+
 	bool status_save_ext_pwr_inserted;
 	bool status_save_batt;
 };
-- 
1.7.4.1

Re: [PATCH v2 0/2] power: introduce Charger-Manager

[MyungJoo Ham]

On Wed, Dec 21, 2011 at 6:36 PM, Donggeun Kim <dg77.kim@samsung.com> wrote:
> Charger Manager provides in-kernel battery charger management that
> requires temperature monitoring during both normal and suspend-to-RAM states
> and where each battery may have multiple chargers attached and the userland
> wants to look at the aggregated information of the multiple chargers.
[]
> Donggeun Kim (2):
>  power: Charger-Manager: add initial Charger-Manager driver
>  power: Charger-Manager: add properties for power-supply-class

Hello Anton, David,

Could you please consider these patches for linux-2.6-battery, which
are "resend patches" of the last "RFC v2" patches of charger-manager?



Cheers! and Happy new year!
MyungJoo

-- 
MyungJoo Ham, Ph.D.
Mobile Software Platform Lab, DMC Business, Samsung Electronics

Re: [PATCH v2 1/2] power: Charger-Manager: add initial Charger-Manager driver

[Rafael J. Wysocki]

On Wednesday, December 21, 2011, Donggeun Kim wrote:
> Because battery health monitoring should be done even when suspended,
> it needs to wake up and suspend periodically. Thus, userspace battery
> monitoring may incur too much overhead; every device and task is woken
> up periodically. Charger Manager uses suspend-again to provide
> in-suspend monitoring.
> 
> This patch allows to monitor battery health in-suspend state.
> 
> Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
>  Documentation/power/charger-manager.txt |  150 ++++++
>  drivers/power/Kconfig                   |    9 +
>  drivers/power/Makefile                  |    1 +
>  drivers/power/charger-manager.c         |  771 +++++++++++++++++++++++++++++++
>  include/linux/power/charger-manager.h   |  131 ++++++
>  5 files changed, 1062 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/power/charger-manager.txt
>  create mode 100644 drivers/power/charger-manager.c
>  create mode 100644 include/linux/power/charger-manager.h
> 
> diff --git a/Documentation/power/charger-manager.txt b/Documentation/power/charger-manager.txt
> new file mode 100644
> index 0000000..99630e5
> --- /dev/null
> +++ b/Documentation/power/charger-manager.txt
> @@ -0,0 +1,150 @@
> +Charger Manager
> +	(C) 2011 MyungJoo Ham <myungjoo.ham@samsung.com>, GPL
> +
> +Charger Manager provides in-kernel battery charger management that
> +requires temperature monitoring during suspend-to-RAM state
> +and where each battery may have multiple chargers attached and the userland
> +wants to look at the aggregated information of the multiple chargers.
> +
> +Charger Manager is a platform_driver with power-supply-class entries.
> +An instance of Charger Manager (a platform-device created with Charger-Manager)
> +represents an independent battery with chargers. If there are multiple
> +batteries with their own chargers acting independently in a system,
> +the system may need multiple instances of Charger Manager.
> +
> +1. Introduction
> +===============
> +
> +Charger Manager supports the following:
> +
> +* Support for multiple chargers (e.g., a device with USB, AC, and solar panels)
> +	A system may have multiple chargers (or power sources) and some of
> +	they may be activated at the same time. Each charger may have its
> +	own power-supply-class and each power-supply-class can provide
> +	different information about the battery status. This framework
> +	aggregates charger-related information from multiple sources and
> +	shows combined information as a single power-supply-class.
> +
> +* Support for in suspend-to-RAM polling (with suspend_again callback)
> +	While the battery is being charged and the system is in suspend-to-RAM,
> +	we may need to monitor the battery health by looking at the ambient or
> +	battery temperature. We can accomplish this by waking up the system
> +	periodically. However, such a method wakes up devices unncessary for
> +	monitoring the battery health and tasks, and user processes that are
> +	supposed to be kept suspended. That, in turn, incurs unnecessary power
> +	consumption and slow down charging process. Or even, such peak power
> +	consumption can stop chargers in the middle of charging
> +	(external power input < device power consumption), which not
> +	only affects the charging time, but the lifespan of the battery.
> +
> +	Charger Manager provides a function "cm_suspend_again" that can be
> +	used as suspend_again callback of platform_suspend_ops. If the platform
> +	requires tasks other than cm_suspend_again, it may implement its own
> +	suspend_again callback that calls cm_suspend_again in the middle.
> +	Normally, the platform will need to resume and suspend some devices
> +	that are used by Charger Manager.
> +
> +2. Global Charger-Manager Data related with suspend_again
> +========================================================
> +In order to setup Charger Manager with suspend-again feature
> +(in-suspend monitoring), the user should provide charger_global_desc
> +with setup_charger_manager(struct charger_global_desc *).
> +This charger_global_desc data for in-suspend monitoring is global
> +as the name suggests. Thus, the user needs to provide only once even
> +if there are multiple batteries. If there are multiple batteries, the
> +multiple instances of Charger Manager share the same charger_global_desc
> +and it will manage in-suspend monitoring for all instances of Charger Manager.
> +
> +The user needs to provide all the three entries properly in order to activate
> +in-suspend monitoring:
> +

There seem to be only two entries in struct charger_global_desc below.

> +struct charger_global_desc {
> +
> +char *rtc;

That should be called rtc_name and I'm not sure if using the name here is
very convenient.  Perhaps it's better if the caller is responsible for
opening the RTC device.

> +	: The name of rtc (e.g., "rtc0") used to wakeup the system from
> +	suspend for Charger Manager. The alarm interrupt (AIE) of the rtc
> +	should be able to wake up the system from suspend. Charger Manager
> +	saves and restores the alarm value and use the previously-defined
> +	alarm if it is going to go off earlier than Charger Manager so that
> +	Charger Manager does not interfere with previously-defined alarms.
> +
> +bool (*is_rtc_only_wakeup_reason)(void);

I'd call that rtc_only_wakeup.

> +	: This callback should let CM know whether
> +	the wakeup-from-suspend is caused only by the alarm of "rtc" in the
> +	same struct. If there is any other wakeup source triggered the
> +	wakeup, it should return false. If the "rtc" is the only wakeup
> +	reason, it should return true.
> +};
> +
> +3. How to setup suspend_again
> +=============================
> +Charger Manager provides a function "extern bool cm_suspend_again(void)".
> +When cm_suspend_again is called, it monitors every battery. The suspend_ops
> +callback of the system's platform_suspend_ops can call cm_suspend_again
> +function to know whether Charger Manager wants to suspend again or not.
> +If there are no other devices or tasks that want to use suspend_again
> +feature, the platform_suspend_ops may directly refer to cm_suspend_again
> +for its suspend_again callback.
> +
> +The cm_suspend_again() returns true (meaning "I want to suspend again")
> +if the system was woken up by Charger Manager and the polling
> +(in-suspend monitoring) results in "normal".
> +
> +4. Charger-Manager Data (struct charger_desc)
> +=============================================
> +For each battery charged independently from other batteries (if a series of
> +batteries are charged by a single charger, they are counted as one independent
> +battery), an instance of Charger Manager is attached to it.
> +
> +struct charger_desc {
> +
> +enum polling_modes polling_mode;
> +	: CM_POLL_DISABLE: do not poll this battery.
> +	  CM_POLL_ALWAYS: always poll this battery.
> +	  CM_POLL_EXTERNAL_POWER_ONLY: poll this battery if and only if
> +				       an external power source is attached.
> +	  CM_POLL_CHARGING_ONLY: poll this battery if and only if the
> +				 battery is being charged.
> +
> +unsigned int polling_interval_ms;
> +	: Required polling interval in ms. Charger Manager will poll
> +	this battery every polling_interval_ms or more frequently.
> +
> +enum data_source battery_present;
> +	CM_FUEL_GAUGE: get battery presence information from fuel gauge.
> +	CM_CHARGER_STAT: get battery presence from chargers.
> +
> +char **psy_charger_stat;

Why do you want to use names here?

> +	: An array ending with NULL that has power-supply-class names of
> +	chargers. Each power-supply-class should provide "PRESENT" (if
> +	battery_present is "CM_CHARGER_STAT"), "ONLINE" (shows whether an
> +	external power source is attached or not), and "STATUS" (shows whether
> +	the battery is {"FULL" or not FULL} or {"FULL", "Charging",
> +	"Discharging", "NotCharging"}).
> +
> +int num_charger_regulators;
> +struct regulator_bulk_data *charger_regulators;
> +	: Regulators representing the chargers in the form for
> +	regulator framework's bulk functions.
> +
> +char *psy_fuel_gauge;
> +	: Power-supply-class name of the fuel gauge.
> +
> +int (*is_temperature_error)(int *mC);

temperature_out_of_range might be a better name here.

> +	: This callback returns 0 if the temperature is safe for charging,
> +	a positive number if it is too hot to charge, and a negative number
> +	if it is too cold to charge. With the variable mC, the callback returns
> +	the temperature in 1/1000 of centigrade.
> +};
> +
> +5. Other Considerations
> +=======================
> +
> +At the charger/battery-related events such as battery-pulled-out,
> +charger-pulled-out, charger-inserted, DCIN-over/under-voltage, charger-stopped,
> +and others critical to chargers, the system should be configured to wake up.
> +At least the following should wake up the system from a suspend:
> +a) charger-on/off b) external-power-in/out c) battery-in/out (while charging)
> +
> +It is usually accomplished by configuring the PMIC as a wakeup source.
> +
> diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
> index 9f88641..92683b5 100644
> --- a/drivers/power/Kconfig
> +++ b/drivers/power/Kconfig
> @@ -236,6 +236,15 @@ config CHARGER_GPIO
>  	  This driver can be build as a module. If so, the module will be
>  	  called gpio-charger.
>  
> +config CHARGER_MANAGER
> +        bool "Battery charger manager for multiple chargers"
> +        help
> +          Say Y to enable charger-manager support, which allows multiple
> +          chargers attached to a battery and multiple batteries attached to a
> +          system. The charger-manager also can monitor charging status in
> +          runtime and in suspend-to-RAM by waking up the system periodically
> +          with help of suspend_again support.
> +
>  config CHARGER_MAX8997
>  	tristate "Maxim MAX8997/MAX8966 PMIC battery charger driver"
>  	depends on MFD_MAX8997 && REGULATOR_MAX8997
> diff --git a/drivers/power/Makefile b/drivers/power/Makefile
> index b4af13d..d3b24e9 100644
> --- a/drivers/power/Makefile
> +++ b/drivers/power/Makefile
> @@ -36,5 +36,6 @@ obj-$(CONFIG_CHARGER_ISP1704)	+= isp1704_charger.o
>  obj-$(CONFIG_CHARGER_MAX8903)	+= max8903_charger.o
>  obj-$(CONFIG_CHARGER_TWL4030)	+= twl4030_charger.o
>  obj-$(CONFIG_CHARGER_GPIO)	+= gpio-charger.o
> +obj-$(CONFIG_CHARGER_MANAGER)	+= charger-manager.o
>  obj-$(CONFIG_CHARGER_MAX8997)	+= max8997_charger.o
>  obj-$(CONFIG_CHARGER_MAX8998)	+= max8998_charger.o
> diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
> new file mode 100644
> index 0000000..5006756
> --- /dev/null
> +++ b/drivers/power/charger-manager.c
> @@ -0,0 +1,771 @@
> +/* linux/drivers/power/charger-manager.c
> + *
> + * Copyright (C) 2011 Samsung Electronics Co., Ltd.
> + * MyungJoo Ham <myungjoo.ham@samsung.com>
> + *
> + * This driver enables to monitor battery health and control charger
> + * during suspend-to-mem.
> + * Charger manager depends on other devices. register this later than
> + * the depending devices.
> + *
> + * 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 <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/irq.h>
> +#include <linux/interrupt.h>
> +#include <linux/rtc.h>
> +#include <linux/slab.h>
> +#include <linux/workqueue.h>
> +#include <linux/platform_device.h>
> +#include <linux/power/charger-manager.h>
> +#include <linux/regulator/consumer.h>
> +
> +/*
> + * Regard CM_JIFFIES_SMALL jiffies is small enough to ignore for
> + * delayed works so that we can run delayed works with CM_JIFFIES_SMALL
> + * without any delays.
> + */
> +#define	CM_JIFFIES_SMALL	(2)

Why do you want to use jiffies instead of ktime?

> +
> +/* If y is valid (> 0) and smaller than x, do x = y */
> +#define CM_MIN_VALID(x, y)	x = (((y > 0) && ((x) > (y))) ? (y) : (x))
> +
> +/*
> + * Regard CM_RTC_SMALL (sec) is small enough to ignore error in invoking
> + * rtc alarm. It should be 2 or larger
> + */
> +#define CM_RTC_SMALL		(2)
> +
> +#define UEVENT_BUF_SIZE		32
> +
> +static LIST_HEAD(cm_list);
> +static DEFINE_MUTEX(cm_list_mtx);
> +
> +/* About in-suspend (suspend-again) monitoring */
> +static struct rtc_device *rtc_dev;
> +static struct rtc_wkalrm rtc_wkalarm_save; /* Backup RTC alarm */
> +static unsigned long rtc_wkalarm_save_; /* 0 if not available */

Those two fields require more explanation or the names should reflect what
they are for (preferably both).

> +static bool cm_suspended;
> +static bool cm_rtc_set;
> +static unsigned long cm_suspend_duration_ms;
> +
> +/* Global charger-manager description */
> +static struct charger_global_desc *g_desc; /* init with setup_charger_manager */
> +
> +/**
> + * is_batt_present - See if the battery presents in place.
> + * @cm: the Charger Manager representing the battery.
> + */
> +static bool is_batt_present(struct charger_manager *cm)
> +{
> +	union power_supply_propval val;
> +	bool present = false;
> +	int i, ret;
> +
> +	switch (cm->desc->battery_present) {
> +	case CM_FUEL_GAUGE:
> +		ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
> +				POWER_SUPPLY_PROP_PRESENT, &val);
> +		if (ret == 0 && val.intval)
> +			present = true;
> +		break;
> +	case CM_CHARGER_STAT:
> +		for (i = 0; cm->charger_stat[i]; i++) {
> +			ret = cm->charger_stat[i]->get_property(
> +					cm->charger_stat[i],
> +					POWER_SUPPLY_PROP_PRESENT, &val);
> +			if (ret == 0 && val.intval) {
> +				present = true;
> +				break;
> +			}
> +		}
> +		break;
> +	}
> +
> +	return present;
> +}
> +
> +/**
> + * is_ext_pwr_online - See if an external power source is attached to charge
> + * @cm: the Charger Manager representing the battery.
> + *
> + * Returns true if at least one of the chargers of the battery has an external
> + * power source attached to charge the battery regardless of whether it is
> + * actually charging or not.
> + */
> +static bool is_ext_pwr_online(struct charger_manager *cm)
> +{
> +	union power_supply_propval val;
> +	bool online = false;
> +	int i, ret;
> +
> +	/* If at least one of them has one, it's yes. */
> +	for (i = 0; cm->charger_stat[i]; i++) {
> +		ret = cm->charger_stat[i]->get_property(
> +				cm->charger_stat[i],
> +				POWER_SUPPLY_PROP_ONLINE, &val);
> +		if (ret == 0 && val.intval) {
> +			online = true;
> +			break;
> +		}
> +	}
> +
> +	return online;
> +}
> +
> +/**
> + * is_charging - Returns true if the battery is being charged.
> + * @cm: the Charger Manager representing the battery.
> + */
> +static bool is_charging(struct charger_manager *cm)
> +{
> +	int i, ret;
> +	bool charging = false;
> +	union power_supply_propval val;
> +
> +	/* If there is no battery, it cannot be charged */
> +	if (!is_batt_present(cm))
> +		return false;
> +
> +	/* If at least one of the charger is charging, return yes */
> +	for (i = 0; cm->charger_stat[i]; i++) {
> +		/* 1. The charger sholuld not be DISABLED */
> +		if (cm->emergency_stop)
> +			continue;
> +		if (!cm->charger_enabled)
> +			continue;
> +
> +		/* 2. The charger should be online (ext-power) */
> +		ret = cm->charger_stat[i]->get_property(
> +				cm->charger_stat[i],
> +				POWER_SUPPLY_PROP_ONLINE, &val);
> +		if (ret) {
> +			dev_warn(cm->dev, "Cannot read ONLINE value from %s.\n",
> +					cm->desc->psy_charger_stat[i]);
> +			continue;
> +		}
> +		if (val.intval == 0)
> +			continue;
> +
> +		/*
> +		 * 3. The charger should not be FULL, DISCHARGING,
> +		 * or NOT_CHARGING.
> +		 */
> +		ret = cm->charger_stat[i]->get_property(
> +				cm->charger_stat[i],
> +				POWER_SUPPLY_PROP_STATUS, &val);
> +		if (ret) {
> +			dev_warn(cm->dev, "Cannot read STATUS value from %s.\n",
> +					cm->desc->psy_charger_stat[i]);
> +			continue;
> +		}
> +		if (val.intval == POWER_SUPPLY_STATUS_FULL ||
> +				val.intval == POWER_SUPPLY_STATUS_DISCHARGING ||
> +				val.intval == POWER_SUPPLY_STATUS_NOT_CHARGING)
> +			continue;
> +
> +		/* Then, this is charging. */
> +		charging = true;
> +		break;
> +	}
> +
> +	return charging;
> +}
> +
> +/**
> + * is_polling_required - Return true if need to continue polling for this CM.
> + * @cm: the Charger Manager representing the battery.
> + */
> +static bool is_polling_required(struct charger_manager *cm)
> +{
> +	switch (cm->desc->polling_mode) {
> +	case CM_POLL_DISABLE:
> +		return false;
> +	case CM_POLL_ALWAYS:
> +		return true;
> +	case CM_POLL_EXTERNAL_POWER_ONLY:
> +		return is_ext_pwr_online(cm);
> +	case CM_POLL_CHARGING_ONLY:
> +		return is_charging(cm);
> +	default:
> +		dev_warn(cm->dev, "Incorrect polling_mode (%d)\n",
> +			cm->desc->polling_mode);
> +	}
> +
> +	return false;
> +}
> +
> +/**
> + * try_charger_enable - Enable/Disable chargers altogether
> + * @cm: the Charger Manager representing the battery.
> + * @enable: true: enable / false: disable
> + *
> + * Note that Charger Manager keeps the charger enabled regardless whether
> + * the charger is charging or not (because battery is full or no external
> + * power source exists) except when CM needs to disable chargers forcibly
> + * bacause of emergency causes; when the battery is overheated or too cold.
> + */
> +static int try_charger_enable(struct charger_manager *cm, bool enable)
> +{
> +	int err = 0, i;
> +	struct charger_desc *desc = cm->desc;
> +
> +	/* Ignore if it's redundent command */
> +	if (enable && cm->charger_enabled)
> +		return 0;
> +	if (!enable && !cm->charger_enabled)
> +		return 0;
> +
> +	if (enable) {
> +		if (cm->emergency_stop)
> +			return -EAGAIN;
> +		err = regulator_bulk_enable(desc->num_charger_regulators,
> +					desc->charger_regulators);
> +	} else {
> +		/*
> +		 * Abnormal battery state - Stop charging forcibly,
> +		 * even if charger was enabled at the other places
> +		 */
> +		err = regulator_bulk_disable(desc->num_charger_regulators,
> +					desc->charger_regulators);
> +
> +		for (i = 0; i < desc->num_charger_regulators; i++) {
> +			if (regulator_is_enabled(
> +				    desc->charger_regulators[i].consumer)) {
> +				regulator_force_disable(
> +					desc->charger_regulators[i].consumer);
> +				dev_warn(cm->dev,
> +					"Disable regulator(%s) forcibly.\n",
> +					desc->charger_regulators[i].supply);
> +			}
> +		}
> +	}
> +
> +	if (!err)
> +		cm->charger_enabled = enable;
> +
> +	return err;
> +}
> +
> +/**
> + * uevent_notify - Let users know something has changed.
> + * @cm: the Charger Manager representing the battery.
> + * @event: the event string.
> + *
> + * If @event is null, it implies that uevent_notify is called
> + * by resume function. When called in the resume function, cm_suspended
> + * should be already reset to false in order to let uevent_notify
> + * notify the recent event during the suspend to users. While
> + * suspended, uevent_notify does not notify users, but tracks
> + * events so that uevent_notify can notify users later after resumed.
> + */
> +static void uevent_notify(struct charger_manager *cm, const char *event)
> +{
> +	static char env_str[UEVENT_BUF_SIZE + 1] = "";
> +	static char env_str_save[UEVENT_BUF_SIZE + 1] = "";
> +
> +	if (cm_suspended) {
> +		/* Nothing in suspended-event buffer */
> +		if (env_str_save[0] == 0) {
> +			if (!strncmp(env_str, event, UEVENT_BUF_SIZE))
> +				return; /* status not changed */
> +			strncpy(env_str_save, event, UEVENT_BUF_SIZE);
> +			return;
> +		}
> +
> +		if (!strncmp(env_str_save, event, UEVENT_BUF_SIZE))
> +			return; /* Duplicated. */
> +		else
> +			strncpy(env_str_save, event, UEVENT_BUF_SIZE);
> +
> +		return;
> +	}
> +
> +	if (event == NULL) {
> +		/* No messages pending */
> +		if (!env_str_save[0])
> +			return;
> +
> +		strncpy(env_str, env_str_save, UEVENT_BUF_SIZE);
> +		kobject_uevent(&cm->dev->kobj, KOBJ_CHANGE);
> +		env_str_save[0] = 0;
> +
> +		return;
> +	}
> +
> +	/* status not changed */
> +	if (!strncmp(env_str, event, UEVENT_BUF_SIZE))
> +		return;
> +
> +	/* save the status and notify the update */
> +	strncpy(env_str, event, UEVENT_BUF_SIZE);
> +	kobject_uevent(&cm->dev->kobj, KOBJ_CHANGE);
> +
> +	dev_info(cm->dev, event);
> +}
> +
> +/**
> + * _cm_monitor - Monitor the temperature and return true for exceptions.
> + * @cm: the Charger Manager representing the battery.
> + *
> + * Returns true if there is an event to notify for the battery.
> + * (True if the status of "emergency_stop" changes)
> + */
> +static bool _cm_monitor(struct charger_manager *cm)
> +{
> +	struct charger_desc *desc = cm->desc;
> +	int temp = desc->is_temperature_error(&cm->last_temp_mC);
> +
> +	dev_dbg(cm->dev, "monitoring (%2.2d.%3.3dC)\n",
> +		cm->last_temp_mC / 1000, cm->last_temp_mC % 1000);
> +
> +	/* It has been stopped already */
> +	if (temp && cm->emergency_stop)
> +		return false;
> +
> +	/* It has been charging already */
> +	if (!temp && !cm->emergency_stop)
> +		return false;
> +

The above two statements may be written as one in the following form:

if (!!temp == !!cm->emergency_stop)
	return false;

> +	if (temp) {
> +		cm->emergency_stop = temp;
> +		if (!try_charger_enable(cm, false)) {
> +			if (temp > 0)
> +				uevent_notify(cm, "OVERHEAT");
> +			else
> +				uevent_notify(cm, "COLD");
> +		}
> +	} else {
> +		cm->emergency_stop = 0;
> +		if (!try_charger_enable(cm, true))
> +			uevent_notify(cm, "CHARGING");
> +	}
> +
> +	return true;
> +}
> +
> +/**
> + * cm_monitor - Monitor every battery.
> + *
> + * Returns true if there is an event to notify from any of the batteries.
> + * (True if the status of "emergency_stop" changes)
> + */
> +static bool cm_monitor(void)
> +{
> +	bool stop = false;
> +	struct charger_manager *cm;
> +
> +	mutex_lock(&cm_list_mtx);
> +
> +	list_for_each_entry(cm, &cm_list, entry)
> +		stop |= _cm_monitor(cm);
> +

That should be

		stop ||= _cm_monitor(cm);

it appears.

> +	mutex_unlock(&cm_list_mtx);
> +
> +	return stop;
> +}
> +
> +/**
> + * cm_setup_timer - For in-suspend monitoring setup wakeup alarm
> + *		    for suspend_again.
> + *
> + * Returns true if the alarm is set for Charger Manager to use.
> + * Returns false if
> + *	cm_setup_timer fails to set an alarm,
> + *	cm_setup_timer does not need to set an alarm for Charger Manager,
> + *	or an alarm previously configured is to be used.
> + */
> +static bool cm_setup_timer(void)
> +{
> +	struct charger_manager *cm;
> +	unsigned int wakeup_ms = UINT_MAX;
> +	bool ret = false;
> +
> +	mutex_lock(&cm_list_mtx);
> +
> +	list_for_each_entry(cm, &cm_list, entry) {
> +		/* Skip if polling is not required for this CM */
> +		if (!is_polling_required(cm) && !cm->emergency_stop)
> +			continue;
> +		if (cm->desc->polling_interval_ms == 0)
> +			continue;
> +		CM_MIN_VALID(wakeup_ms, cm->desc->polling_interval_ms);
> +	}
> +
> +	mutex_unlock(&cm_list_mtx);
> +
> +	if (wakeup_ms < UINT_MAX && wakeup_ms > 0) {
> +		pr_info("Charger Manager wakeup timer: %u ms.\n", wakeup_ms);
> +		if (rtc_dev) {
> +			struct rtc_wkalrm tmp;
> +			unsigned long time, now;
> +			unsigned long add = DIV_ROUND_UP(wakeup_ms, 1000);
> +
> +			/*
> +			 * Set alarm with the polling interval (wakeup_ms)
> +			 * except when rtc_wkalarm_save comes first.
> +			 * However, the alarm time should be NOW +
> +			 * CM_RTC_SMALL or later.
> +			 */
> +			tmp.enabled = 1;
> +			rtc_read_time(rtc_dev, &tmp.time);
> +			rtc_tm_to_time(&tmp.time, &now);
> +			if (add < CM_RTC_SMALL)
> +				add = CM_RTC_SMALL;
> +			time = now + add;
> +
> +			ret = true;
> +
> +			if (rtc_wkalarm_save.enabled && rtc_wkalarm_save_ &&
> +			    rtc_wkalarm_save_ < time) {
> +				if (rtc_wkalarm_save_ < now + CM_RTC_SMALL)
> +					time = now + CM_RTC_SMALL;
> +				else
> +					time = rtc_wkalarm_save_;
> +
> +				/* The timer is not appointed by CM */
> +				ret = false;
> +			}
> +
> +			pr_info("Waking up after %lu secs.\n",
> +					time - now);
> +
> +			rtc_time_to_tm(time, &tmp.time);
> +			rtc_set_alarm(rtc_dev, &tmp);
> +			cm_suspend_duration_ms += wakeup_ms;
> +			return ret;
> +		}
> +	}
> +
> +	if (rtc_dev)
> +		rtc_set_alarm(rtc_dev, &rtc_wkalarm_save);
> +	return false;
> +}
> +
> +/**
> + * cm_suspend_again - Determine whether suspend again or not
> + *
> + * Returns true if the system should be suspended again
> + * Returns false if the system should be woken up
> + */
> +bool cm_suspend_again(void)
> +{
> +	struct charger_manager *cm;
> +	bool ret = false;
> +
> +	if (!g_desc)
> +		return false;
> +	if (!g_desc->is_rtc_only_wakeup_reason)
> +		return false;
> +	if (!g_desc->is_rtc_only_wakeup_reason())
> +		return false;
> +	if (!cm_rtc_set)
> +		return false;

Use || and write the above as one statement, perhaps?

> +
> +	if (cm_monitor())
> +		goto out;
> +
> +	ret = true;
> +	mutex_lock(&cm_list_mtx);
> +	list_for_each_entry(cm, &cm_list, entry) {
> +		if (cm->status_save_ext_pwr_inserted != is_ext_pwr_online(cm) ||
> +		    cm->status_save_batt != is_batt_present(cm))
> +			ret = false;
> +	}
> +	mutex_unlock(&cm_list_mtx);
> +
> +	cm_rtc_set = cm_setup_timer();
> +out:
> +	/* It's about the time when the non-CM appointed timer goes off */
> +	if (rtc_wkalarm_save.enabled) {
> +		unsigned long now;
> +		struct rtc_time tmp;
> +
> +		rtc_read_time(rtc_dev, &tmp);
> +		rtc_tm_to_time(&tmp, &now);
> +
> +		if (rtc_wkalarm_save_ &&
> +		    now + CM_RTC_SMALL >= rtc_wkalarm_save_)
> +			return false;
> +	}
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(cm_suspend_again);
> +
> +/**
> + * setup_charger_manager - initialize charger_global_desc data
> + * @gd: pointer to instance of charger_global_desc
> + */
> +int setup_charger_manager(struct charger_global_desc *gd)
> +{
> +	if (!gd)
> +		return -EINVAL;
> +
> +	if (rtc_dev)
> +		rtc_class_close(rtc_dev);
> +	rtc_dev = NULL;
> +	g_desc = NULL;
> +
> +	if (!gd->is_rtc_only_wakeup_reason) {
> +		pr_err("The callback is_wktimer_only_wkreason is not given.\n");
> +		return -EINVAL;
> +	}
> +
> +	if (gd->rtc) {
> +		rtc_dev = rtc_class_open(gd->rtc);
> +		if (IS_ERR_OR_NULL(rtc_dev)) {
> +			rtc_dev = NULL;
> +			/* Retry at probe. RTC may be not registered yet */
> +		}
> +	} else {
> +		pr_warn("No wktimer is given for charger manager."
> +			"In-suspend monitoring won't work.\n");
> +	}
> +
> +	g_desc = gd;
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(setup_charger_manager);
> +
> +static int charger_manager_probe(struct platform_device *pdev)
> +{
> +	struct charger_desc *desc = dev_get_platdata(&pdev->dev);
> +	struct charger_manager *cm;
> +	int ret = 0, i;
> +
> +	if (g_desc && !rtc_dev && g_desc->rtc) {
> +		rtc_dev = rtc_class_open(g_desc->rtc);
> +		if (IS_ERR_OR_NULL(rtc_dev)) {
> +			rtc_dev = NULL;
> +			dev_err(&pdev->dev, "Cannot get RTC %s.\n",
> +				g_desc->rtc);
> +			ret = -ENODEV;
> +			goto err_alloc;
> +		}
> +	}
> +
> +	if (!desc) {
> +		dev_err(&pdev->dev, "No platform data (desc) found.\n");
> +		ret = -ENODEV;
> +		goto err_alloc;
> +	}

Is there any way to detect whether dev_get_platdata(&pdev->dev) really points
to an instance of struct charger_desc ?

> +
> +	cm = kzalloc(sizeof(struct charger_manager), GFP_KERNEL);
> +	if (!cm) {
> +		dev_err(&pdev->dev, "Cannot allocate memory.\n");
> +		ret = -ENOMEM;
> +		goto err_alloc;
> +	}
> +
> +	/* Basic Values. Unspecified are Null or 0 */
> +	cm->dev = &pdev->dev;
> +	cm->desc = desc;
> +	cm->last_temp_mC = INT_MIN; /* denotes "unmeasured, yet" */
> +
> +	if (!desc->charger_regulators || desc->num_charger_regulators < 1) {
> +		ret = -EINVAL;
> +		dev_err(&pdev->dev, "charger_regulators undefined.\n");
> +		goto err_no_charger;
> +	}
> +
> +	ret = regulator_bulk_get(&pdev->dev, desc->num_charger_regulators,
> +				 desc->charger_regulators);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Cannot get charger regulators.\n");
> +		goto err_no_charger;
> +	}
> +
> +	if (!desc->psy_charger_stat || !desc->psy_charger_stat[0]) {
> +		dev_err(&pdev->dev, "No power supply defined.\n");
> +		ret = -EINVAL;
> +		goto err_no_charger_stat;
> +	}

It might be better to check that before calling regulator_bulk_get().

> +
> +	for (i = 0; desc->psy_charger_stat[i]; i++)
> +		/* Counting index only */ ;

In my opinion it would be better to write the above and a while() loop.

Also, that wouldn't be necessary at all if the number of psy_charger_stat
entries were stored in desc.

> +
> +	cm->charger_stat = kzalloc(sizeof(struct power_supply *) * (i + 1),
> +				   GFP_KERNEL);
> +	if (!cm->charger_stat) {
> +		ret = -ENOMEM;
> +		goto err_no_charger_stat;
> +	}
> +
> +	for (i = 0; desc->psy_charger_stat[i]; i++) {
> +		cm->charger_stat[i] = power_supply_get_by_name(
> +					desc->psy_charger_stat[i]);
> +		if (!cm->charger_stat[i]) {
> +			dev_err(&pdev->dev, "Cannot find power supply "
> +					"\"%s\"\n",
> +					desc->psy_charger_stat[i]);
> +			ret = -ENODEV;
> +			goto err_chg_stat;
> +		}
> +	}
> +
> +	cm->fuel_gauge = power_supply_get_by_name(desc->psy_fuel_gauge);
> +	if (!cm->fuel_gauge) {
> +		dev_err(&pdev->dev, "Cannot find power supply \"%s\"\n",
> +				desc->psy_fuel_gauge);
> +		ret = -ENODEV;
> +		goto err_chg_stat;
> +	}
> +
> +	if (desc->polling_interval_ms == 0 ||
> +	    msecs_to_jiffies(desc->polling_interval_ms) <= CM_JIFFIES_SMALL) {
> +		dev_err(&pdev->dev, "polling_interval_ms is too small\n");
> +		ret = -EINVAL;
> +		goto err_chg_stat;
> +	}
> +
> +	if (!desc->is_temperature_error) {
> +		dev_err(&pdev->dev, "there is no is_temperature_error\n");
> +		ret = -EINVAL;
> +		goto err_chg_stat;
> +	}
> +
> +	platform_set_drvdata(pdev, cm);
> +
> +	ret = try_charger_enable(cm, true);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Cannot enable charger regulators\n");
> +		goto err_chg_stat;
> +	}
> +
> +	/* Add to the list */
> +	mutex_lock(&cm_list_mtx);
> +	list_add(&cm->entry, &cm_list);
> +	mutex_unlock(&cm_list_mtx);
> +
> +	return 0;
> +
> +err_chg_stat:
> +	kfree(cm->charger_stat);
> +err_no_charger_stat:
> +	if (desc->charger_regulators)
> +		regulator_bulk_free(desc->num_charger_regulators,
> +					desc->charger_regulators);
> +err_no_charger:
> +	kfree(cm);
> +err_alloc:
> +	return ret;
> +}
> +
> +static int __devexit charger_manager_remove(struct platform_device *pdev)
> +{
> +	struct charger_manager *cm = platform_get_drvdata(pdev);
> +	struct charger_desc *desc = cm->desc;
> +
> +	/* Remove from the list */
> +	mutex_lock(&cm_list_mtx);
> +	list_del(&cm->entry);
> +	mutex_unlock(&cm_list_mtx);
> +
> +	kfree(cm->charger_stat);
> +	if (desc->charger_regulators)
> +		regulator_bulk_free(desc->num_charger_regulators,
> +					desc->charger_regulators);
> +	kfree(cm);
> +	return 0;
> +}
> +
> +const struct platform_device_id charger_manager_id[] = {
> +	{ "charger-manager", 0 },
> +	{ },
> +};
> +

The prepare/complete routines look good to me.

Thanks,
Rafael

Re: [PATCH v2 1/2] power: Charger-Manager: add initial Charger-Manager driver

[MyungJoo Ham]

2011/12/27 Rafael J. Wysocki <rjw@sisk.pl>:
> That should be called rtc_name and I'm not sure if using the name here is
> very convenient.  Perhaps it's better if the caller is responsible for
> opening the RTC device.

Hi Rafael,

Because struct rtc_device is created at rtc_device_register() call of
rtc device driver, the caller (rtc drivers are not supposed to create
charger manager) needs to call rtc_class_open(rtc_name) in order to
feed struct rtc_device to charger manager. Thus, I think that
enforcing the caller to provide struct rtc_device has no significant
benefit. Besides, it would prohibit statically defining struct
charger_global_desc: cannot define struct charger_global_desc example
= { .rtc_device = rtc_class_open("blahblah") };

>> +#define      CM_JIFFIES_SMALL        (2)
>
> Why do you want to use jiffies instead of ktime?
>

It is based on work schedule, which is based on jiffies. If we define
the "small time" with ktime, it should be translated to jiffies
anyway.

>> +static int charger_manager_probe(struct platform_device *pdev)
>> +{
>> +     struct charger_desc *desc = dev_get_platdata(&pdev->dev);
[]
>> +     if (!desc) {
>> +             dev_err(&pdev->dev, "No platform data (desc) found.\n");
>> +             ret = -ENODEV;
>> +             goto err_alloc;
>> +     }
>
> Is there any way to detect whether dev_get_platdata(&pdev->dev) really points
> to an instance of struct charger_desc ?

We are verifying the member values (whether they are in the proper
ranges) later in this probe function.
Other than that, I don't know a method to detect whether this pointer
is really pointing to struct charger_desc except for simply checking
whether it is NULL or not or enforcing users to add some magic values
in the struct to check (like mutex debug mode).

>> +     /* Basic Values. Unspecified are Null or 0 */
>> +     cm->dev = &pdev->dev;
>> +     cm->desc = desc;

We will let cm->desc to alloc some space and copy contents of desc
into cm->desc because desc may be __initdata.



Donggeun will update and submit patchset v3 mostly based on your
valueable comments.

Thank you so much, Rafael.


Cheers! And happy new year!
MyungJoo

-- 
MyungJoo Ham, Ph.D.
Mobile Software Platform Lab, DMC Business, Samsung Electronics