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Subject[PATCH 1/2] power_supply: Charger-Manager: poll battery health in normal state
Date
Charger-Manager needs to check battery health in normal state
as well as suspend-to-RAM state.
When the battery is fully charged,
Charger-Manager needs to determine when the chargers restart charging.

This patch allows Charger-Manager to monitor battery health in normal state
and handle operation for chargers after battery is fully charged.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
Documentation/power/charger-manager.txt | 25 ++++-
drivers/power/charger-manager.c | 230 +++++++++++++++++++++++++++++++
include/linux/power/charger-manager.h | 25 ++++
3 files changed, 279 insertions(+), 1 deletions(-)
diff --git a/Documentation/power/charger-manager.txt b/Documentation/power/charger-manager.txt
index fdcca99..47f7fdc 100644
--- a/Documentation/power/charger-manager.txt
+++ b/Documentation/power/charger-manager.txt
@@ -44,6 +44,12 @@ Charger Manager supports the following:
Normally, the platform will need to resume and suspend some devices
that are used by Charger Manager.

+* Support for premature full-battery event handling
+ If the battery voltage drops by "fullbatt_vchkdrop_uV" after
+ "fullbatt_vchkdrop_ms" from the full-battery event, the framework
+ restarts charging. This check is also performed while suspended by
+ setting wakeup time accordingly and using suspend_again.
+
2. Global Charger-Manager Data related with suspend_again
========================================================
In order to setup Charger Manager with suspend-again feature
@@ -55,7 +61,7 @@ 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 two entries properly in order to activate
+The user needs to provide all the three entries properly in order to activate
in-suspend monitoring:

struct charger_global_desc {
@@ -74,6 +80,11 @@ bool (*rtc_only_wakeup)(void);
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.
+
+bool assume_timer_stops_in_suspend;
+ : if true, Charger Manager assumes that
+ the timer (CM uses jiffies as timer) stops during suspend. Then, CM
+ assumes that the suspend-duration is same as the alarm length.
};

3. How to setup suspend_again
@@ -111,6 +122,16 @@ enum polling_modes polling_mode;
CM_POLL_CHARGING_ONLY: poll this battery if and only if the
battery is being charged.

+unsigned int fullbatt_vchkdrop_ms;
+unsigned int fullbatt_vchkdrop_uV;
+ : If both have non-zero values, Charger Manager will check the
+ battery voltage drop fullbatt_vchkdrop_ms after the battery is fully
+ charged. If the voltage drop is over fullbatt_vchkdrop_uV, Charger
+ Manager will try to recharge the battery by disabling and enabling
+ chargers. Recharge with voltage drop condition only (without delay
+ condition) is needed to be implemented with hardware interrupts from
+ fuel gauges or charger devices/chips.
+
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
@@ -122,6 +143,8 @@ unsigned int polling_interval_ms;
this battery every polling_interval_ms or more frequently.

enum data_source battery_present;
+ : CM_ASSUME_ALWAYS_TRUE: assume that the battery exists.
+ CM_ASSUME_ALWAYS_FALSE: assume that the battery does not exists.
CM_FUEL_GAUGE: get battery presence information from fuel gauge.
CM_CHARGER_STAT: get battery presence from chargers.

diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
index 88fd971..9ecde4c 100644
--- a/drivers/power/charger-manager.c
+++ b/drivers/power/charger-manager.c
@@ -57,6 +57,12 @@ static bool cm_suspended;
static bool cm_rtc_set;
static unsigned long cm_suspend_duration_ms;

+/* About normal (not suspended) monitoring */
+static unsigned long polling_jiffy = ULONG_MAX; /* ULONG_MAX: no polling */
+static unsigned long next_polling; /* Next appointed polling time */
+static struct workqueue_struct *cm_wq; /* init at driver add */
+static struct delayed_work cm_monitor_work; /* init at driver add */
+
/* Global charger-manager description */
static struct charger_global_desc *g_desc; /* init with setup_charger_manager */

@@ -71,6 +77,12 @@ static bool is_batt_present(struct charger_manager *cm)
int i, ret;

switch (cm->desc->battery_present) {
+ case CM_ASSUME_ALWAYS_TRUE:
+ present = true;
+ break;
+ case CM_ASSUME_ALWAYS_FALSE:
+ present = false;
+ break;
case CM_FUEL_GAUGE:
ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
POWER_SUPPLY_PROP_PRESENT, &val);
@@ -282,6 +294,26 @@ static int try_charger_enable(struct charger_manager *cm, bool enable)
}

/**
+ * try_charger_restart - Restart charging.
+ * @cm: the Charger Manager representing the battery.
+ *
+ * Restart charging by turning off and on the charger.
+ */
+static int try_charger_restart(struct charger_manager *cm)
+{
+ int err;
+
+ if (cm->emergency_stop)
+ return -EAGAIN;
+
+ err = try_charger_enable(cm, false);
+ if (err)
+ return err;
+
+ return try_charger_enable(cm, true);
+}
+
+/**
* uevent_notify - Let users know something has changed.
* @cm: the Charger Manager representing the battery.
* @event: the event string.
@@ -339,6 +371,47 @@ static void uevent_notify(struct charger_manager *cm, const char *event)
}

/**
+ * fullbatt_vchk - Check voltage drop some times after "FULL" event.
+ * @work: the work_struct appointing the function
+ *
+ * If a user has designated "fullbatt_vchkdrop_ms/uV" values with
+ * charger_desc, Charger Manager checks voltage drop after the battery
+ * "FULL" event. It checks whether the voltage has dropped more than
+ * fullbatt_vchkdrop_uV by calling this function after fullbatt_vchkrop_ms.
+ */
+static void fullbatt_vchk(struct work_struct *work)
+{
+ struct delayed_work *dwork =
+ container_of(work, struct delayed_work, work);
+ struct charger_manager *cm = container_of(dwork,
+ struct charger_manager, fullbatt_vchk_work);
+ struct charger_desc *desc = cm->desc;
+ int batt_uV, err, diff;
+
+ /* remove the appointment for fullbatt_vchk */
+ cm->fullbatt_vchk_jiffies_at = 0;
+
+ if (!desc->fullbatt_vchkdrop_uV || !desc->fullbatt_vchkdrop_ms)
+ return;
+
+ err = get_batt_uV(cm, &batt_uV);
+ if (err) {
+ dev_err(cm->dev, "%s: get_batt_uV error(%d).\n", __func__, err);
+ return;
+ }
+
+ diff = cm->fullbatt_vchk_uV;
+ diff -= batt_uV;
+
+ dev_dbg(cm->dev, "VBATT dropped %duV after full-batt.\n", diff);
+
+ if (diff > desc->fullbatt_vchkdrop_uV) {
+ try_charger_restart(cm);
+ uevent_notify(cm, "Recharge");
+ }
+}
+
+/**
* _cm_monitor - Monitor the temperature and return true for exceptions.
* @cm: the Charger Manager representing the battery.
*
@@ -395,6 +468,68 @@ static bool cm_monitor(void)
return stop;
}

+/**
+ * _setup_polling - Setup the next instance of polling.
+ * @work: work_struct of the function _setup_polling.
+ */
+static void _setup_polling(struct work_struct *work)
+{
+ unsigned long min = ULONG_MAX;
+ struct charger_manager *cm;
+ bool keep_polling = false;
+ unsigned long _next_polling;
+
+ mutex_lock(&cm_list_mtx);
+
+ list_for_each_entry(cm, &cm_list, entry) {
+ if (is_polling_required(cm) && cm->desc->polling_interval_ms) {
+ keep_polling = true;
+
+ if (min > cm->desc->polling_interval_ms)
+ min = cm->desc->polling_interval_ms;
+ }
+ }
+
+ polling_jiffy = msecs_to_jiffies(min);
+ if (polling_jiffy <= CM_JIFFIES_SMALL)
+ polling_jiffy = CM_JIFFIES_SMALL + 1;
+
+ if (!keep_polling)
+ polling_jiffy = ULONG_MAX;
+ if (polling_jiffy == ULONG_MAX)
+ goto out;
+
+ WARN(cm_wq == NULL, "charger-manager: workqueue not initialized"
+ ". try it later. %s\n", __func__);
+
+ _next_polling = jiffies + polling_jiffy;
+
+ if (!delayed_work_pending(&cm_monitor_work) ||
+ (delayed_work_pending(&cm_monitor_work) &&
+ time_after(next_polling, _next_polling))) {
+ cancel_delayed_work(&cm_monitor_work);
+ next_polling = jiffies + polling_jiffy;
+ queue_delayed_work(cm_wq, &cm_monitor_work, polling_jiffy);
+ }
+
+out:
+ mutex_unlock(&cm_list_mtx);
+}
+static DECLARE_WORK(setup_polling, _setup_polling);
+
+/**
+ * cm_monitor_poller - The Monitor / Poller.
+ * @work: work_struct of the function cm_monitor_poller
+ *
+ * During non-suspended state, cm_monitor_poller is used to poll and monitor
+ * the batteries.
+ */
+static void cm_monitor_poller(struct work_struct *work)
+{
+ cm_monitor();
+ schedule_work(&setup_polling);
+}
+
static int charger_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
@@ -616,6 +751,20 @@ static bool cm_setup_timer(void)
mutex_lock(&cm_list_mtx);

list_for_each_entry(cm, &cm_list, entry) {
+ unsigned int fbchk_ms = 0;
+
+ /* fullbatt_vchk is required. setup timer for that */
+ if (cm->fullbatt_vchk_jiffies_at) {
+ fbchk_ms = jiffies_to_msecs(cm->fullbatt_vchk_jiffies_at
+ - jiffies);
+ if (cm->fullbatt_vchk_jiffies_at <= jiffies ||
+ msecs_to_jiffies(fbchk_ms) < CM_JIFFIES_SMALL) {
+ fullbatt_vchk(&cm->fullbatt_vchk_work.work);
+ fbchk_ms = 0;
+ }
+ }
+ CM_MIN_VALID(wakeup_ms, fbchk_ms);
+
/* Skip if polling is not required for this CM */
if (!is_polling_required(cm) && !cm->emergency_stop)
continue;
@@ -675,6 +824,27 @@ static bool cm_setup_timer(void)
return false;
}

+static bool _cm_fbchk_in_suspend(struct charger_manager *cm)
+{
+ unsigned long jiffy_now = jiffies;
+
+ if (!cm->fullbatt_vchk_jiffies_at)
+ return false;
+
+ if (g_desc && g_desc->assume_timer_stops_in_suspend)
+ jiffy_now += msecs_to_jiffies(cm_suspend_duration_ms);
+
+ /* Execute now if it's going to be executed not too long after */
+ jiffy_now += CM_JIFFIES_SMALL;
+
+ if (time_after_eq(jiffy_now, cm->fullbatt_vchk_jiffies_at)) {
+ fullbatt_vchk(&cm->fullbatt_vchk_work.work);
+ return true;
+ }
+
+ return false;
+}
+
/**
* cm_suspend_again - Determine whether suspend again or not
*
@@ -696,6 +866,8 @@ bool cm_suspend_again(void)
ret = true;
mutex_lock(&cm_list_mtx);
list_for_each_entry(cm, &cm_list, entry) {
+ _cm_fbchk_in_suspend(cm);
+
if (cm->status_save_ext_pwr_inserted != is_ext_pwr_online(cm) ||
cm->status_save_batt != is_batt_present(cm))
ret = false;
@@ -797,6 +969,21 @@ static int charger_manager_probe(struct platform_device *pdev)
memcpy(cm->desc, desc, sizeof(struct charger_desc));
cm->last_temp_mC = INT_MIN; /* denotes "unmeasured, yet" */

+ /*
+ * The following two do not need to be errors.
+ * Users may intentionally ignore those two features.
+ */
+ if (desc->fullbatt_uV == 0) {
+ dev_info(&pdev->dev, "Ignoring full-battery voltage threshold"
+ " as it is not supplied.");
+ }
+ if (!desc->fullbatt_vchkdrop_ms || !desc->fullbatt_vchkdrop_uV) {
+ dev_info(&pdev->dev, "Disabling full-battery voltage drop "
+ "checking mechanism as it is not supplied.");
+ desc->fullbatt_vchkdrop_ms = 0;
+ desc->fullbatt_vchkdrop_uV = 0;
+ }
+
if (!desc->charger_regulators || desc->num_charger_regulators < 1) {
ret = -EINVAL;
dev_err(&pdev->dev, "charger_regulators undefined.\n");
@@ -905,6 +1092,8 @@ static int charger_manager_probe(struct platform_device *pdev)
cm->charger_psy.num_properties++;
}

+ INIT_DELAYED_WORK(&cm->fullbatt_vchk_work, fullbatt_vchk);
+
ret = power_supply_register(NULL, &cm->charger_psy);
if (ret) {
dev_err(&pdev->dev, "Cannot register charger-manager with"
@@ -930,6 +1119,8 @@ static int charger_manager_probe(struct platform_device *pdev)
list_add(&cm->entry, &cm_list);
mutex_unlock(&cm_list_mtx);

+ schedule_work(&setup_polling);
+
return 0;

err_chg_enable:
@@ -961,10 +1152,14 @@ static int __devexit charger_manager_remove(struct platform_device *pdev)
list_del(&cm->entry);
mutex_unlock(&cm_list_mtx);

+ schedule_work(&setup_polling);
+
if (desc->charger_regulators)
regulator_bulk_free(desc->num_charger_regulators,
desc->charger_regulators);

+ try_charger_enable(cm, false);
+
power_supply_unregister(&cm->charger_psy);
kfree(cm->charger_psy.properties);
kfree(cm->charger_stat);
@@ -1007,6 +1202,7 @@ static int cm_suspend_prepare(struct device *dev)
cm_suspended = true;
}

+ cancel_delayed_work(&cm->fullbatt_vchk_work);
cm->status_save_ext_pwr_inserted = is_ext_pwr_online(cm);
cm->status_save_batt = is_batt_present(cm);

@@ -1036,6 +1232,34 @@ static void cm_suspend_complete(struct device *dev)
cm_rtc_set = false;
}

+ /* Re-enqueue delayed work (fullbatt_vchk_work) */
+ if (cm->fullbatt_vchk_jiffies_at) {
+ unsigned long delay = 0;
+ unsigned long now = jiffies;
+
+ if (time_after_eq(now + CM_JIFFIES_SMALL,
+ cm->fullbatt_vchk_jiffies_at)) {
+ delay = (unsigned long)((long)(now + CM_JIFFIES_SMALL)
+ - (long)(cm->fullbatt_vchk_jiffies_at));
+ delay = jiffies_to_msecs(delay);
+ } else {
+ delay = 0;
+ }
+
+ /*
+ * Account for cm_suspend_duration_ms if
+ * assume_timer_stops_in_suspend is active
+ */
+ if (g_desc && g_desc->assume_timer_stops_in_suspend) {
+ if (delay > cm_suspend_duration_ms)
+ delay -= cm_suspend_duration_ms;
+ else
+ delay = 0;
+ }
+
+ queue_delayed_work(cm_wq, &cm->fullbatt_vchk_work,
+ msecs_to_jiffies(delay));
+ }
uevent_notify(cm, NULL);
}

@@ -1057,12 +1281,18 @@ static struct platform_driver charger_manager_driver = {

static int __init charger_manager_init(void)
{
+ cm_wq = create_freezable_workqueue("charger_manager");
+ INIT_DELAYED_WORK(&cm_monitor_work, cm_monitor_poller);
+
return platform_driver_register(&charger_manager_driver);
}
late_initcall(charger_manager_init);

static void __exit charger_manager_cleanup(void)
{
+ destroy_workqueue(cm_wq);
+ cm_wq = NULL;
+
platform_driver_unregister(&charger_manager_driver);
}
module_exit(charger_manager_cleanup);
diff --git a/include/linux/power/charger-manager.h b/include/linux/power/charger-manager.h
index 4f75e53..78b9865 100644
--- a/include/linux/power/charger-manager.h
+++ b/include/linux/power/charger-manager.h
@@ -18,6 +18,8 @@
#include <linux/power_supply.h>

enum data_source {
+ CM_ASSUME_ALWAYS_TRUE,
+ CM_ASSUME_ALWAYS_FALSE,
CM_FUEL_GAUGE,
CM_CHARGER_STAT,
};
@@ -38,11 +40,18 @@ enum polling_modes {
* rtc_only_wakeup() returning false.
* If the RTC given to CM is the only wakeup reason,
* rtc_only_wakeup should return true.
+ * @assume_timer_stops_in_suspend:
+ * Assume that the jiffy timer stops in suspend-to-RAM.
+ * When enabled, CM does not rely on jiffies value in
+ * suspend_again and assumes that jiffies value does not
+ * change during suspend.
*/
struct charger_global_desc {
char *rtc_name;

bool (*rtc_only_wakeup)(void);
+
+ bool assume_timer_stops_in_suspend;
};

/**
@@ -50,6 +59,11 @@ struct charger_global_desc {
* @psy_name: the name of power-supply-class for charger manager
* @polling_mode:
* Determine which polling mode will be used
+ * @fullbatt_vchkdrop_ms:
+ * @fullbatt_vchkdrop_uV:
+ * Check voltage drop after the battery is fully charged.
+ * If it has dropped more than fullbatt_vchkdrop_uV after
+ * fullbatt_vchkdrop_ms, CM will restart charging.
* @fullbatt_uV: voltage in microvolt
* If it is not being charged and VBATT >= fullbatt_uV,
* it is assumed to be full.
@@ -76,6 +90,8 @@ struct charger_desc {
enum polling_modes polling_mode;
unsigned int polling_interval_ms;

+ unsigned int fullbatt_vchkdrop_ms;
+ unsigned int fullbatt_vchkdrop_uV;
unsigned int fullbatt_uV;

enum data_source battery_present;
@@ -101,6 +117,11 @@ struct charger_desc {
* @fuel_gauge: power_supply for fuel gauge
* @charger_stat: array of power_supply for chargers
* @charger_enabled: the state of charger
+ * @fullbatt_vchk_jiffies_at:
+ * jiffies at the time full battery check will occur.
+ * @fullbatt_vchk_uV: voltage in microvolt
+ * criteria for full battery
+ * @fullbatt_vchk_work: work queue for full battery check
* @emergency_stop:
* When setting true, stop charging
* @last_temp_mC: the measured temperature in milli-Celsius
@@ -121,6 +142,10 @@ struct charger_manager {

bool charger_enabled;

+ unsigned long fullbatt_vchk_jiffies_at;
+ unsigned int fullbatt_vchk_uV;
+ struct delayed_work fullbatt_vchk_work;
+
int emergency_stop;
int last_temp_mC;

--
1.7.4.1


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