power_supply: Charger-Manager: provide function for in-kernel use

Quoted 57 lines · Donggeun Kim

By using cm_notify_event function,
charger driver can report several charger events
(e.g. battery full and external power in/out, etc) to Charger-Manager. Charger-Manager can properly and immediately control chargers by the reported event.

Signed-off-by MyungJoo Ham <[email protected]>

Signed-off-by Donggeun Kim <[email protected]>

Signed-off-by Kyungmin Park <[email protected]>

---
 Documentation/power/charger-manager.txt |   16 +++-
 drivers/power/charger-manager.c         |  157 +++++++++++++++++++++++++++++++
 include/linux/power/charger-manager.h   |   18 ++++
 3 files changed, 190 insertions(+), 1 deletions(-)

Documentation/power/charger-manager.txt +15 -1

index 47f7fdc..f6566c7 100644
@@ -50,6 +50,10 @@ Charger Manager supports the following:
 	restarts charging. This check is also performed while suspended by
 	setting wakeup time accordingly and using suspend_again.
 
+* Support for uevent-notify
+	With the charger-related events, the device sends
+	notification to users with UEVENT.
+
 2. Global Charger-Manager Data related with suspend_again
 ========================================================
 In order to setup Charger Manager with suspend-again feature

@@ -174,7 +178,17 @@ bool measure_battery_temp;
 	the value of measure_battery_temp.
 };
 
-5. Other Considerations
+5. Notify Charger-Manager of charger events: cm_notify_event()
+=========================================================
+If there is an charger event is required to notify
+Charger Manager, a charger device driver that triggers the event can call
+cm_notify_event(psy, type, msg) to notify the corresponding Charger Manager.
+In the function, psy is the charger driver's power_supply pointer, which is
+associated with Charger-Manager. The parameter "type"
+is the same as irq's type (enum cm_event_types). The event message "msg" is
+optional and is effective only if the event type is "UNDESCRIBED" or "OTHERS".
+
+6. Other Considerations
 =======================
 
 At the charger/battery-related events such as battery-pulled-out,

drivers/power/charger-manager.c +0 -0

index 9ecde4c..8cf0d42 100644
@@ -23,6 +23,16 @@
 #include <linux/power/charger-manager.h>
 #include <linux/regulator/consumer.h>
 

drivers/power/charger-manager.c line 27

Quoted 2 lines

drivers/power/charger-manager.c +2 -0

+static const char * const default_event_names[] = {
+	[CM_EVENT_UNDESCRIBED] = "Undescribed",

"Unknown" perhaps?

Quoted 25 lines

drivers/power/charger-manager.c +17 -0

+	[CM_EVENT_BATT_FULL] = "Battery Full",
+	[CM_EVENT_BATT_IN] = "Battery Inserted",
+	[CM_EVENT_BATT_OUT] = "Battery Pulled Out",
+	[CM_EVENT_EXT_PWR_IN_OUT] = "External Power Attach/Detach",
+	[CM_EVENT_CHG_START_STOP] = "Charging Start/Stop",
+	[CM_EVENT_OTHERS] = "Other battery events"
+};
+
 /*
  * Regard CM_JIFFIES_SMALL jiffies is small enough to ignore for
  * delayed works so that we can run delayed works with CM_JIFFIES_SMALL

@@ -530,6 +540,68 @@ static void cm_monitor_poller(struct work_struct *work)
 	schedule_work(&setup_polling);
 }
 
+/**
+ * fullbatt_handler - Event handler for CM_EVENT_BATT_FULL
+ * @cm: the Charger Manager representing the battery.
+ */
+static void fullbatt_handler(struct charger_manager *cm)
+{
+	struct charger_desc *desc = cm->desc;
+
+	if (!desc->fullbatt_vchkdrop_uV || !desc->fullbatt_vchkdrop_ms)

drivers/power/charger-manager.c static void cm_monitor_poller(struct work_struct *work) · line 557

Quoted 6 lines

drivers/power/charger-manager.c +6 -0

+		goto out;
+
+	if (cm_suspended)
+		cm->cancel_suspend = true;
+
+	cancel_delayed_work(&cm->fullbatt_vchk_work);

Is cancel_delayed_work() sufficient here?

Quoted 127 lines

drivers/power/charger-manager.c +101 -0

+	queue_delayed_work(cm_wq, &cm->fullbatt_vchk_work,
+			   msecs_to_jiffies(desc->fullbatt_vchkdrop_ms));
+	cm->fullbatt_vchk_jiffies_at = jiffies + msecs_to_jiffies(
+				       desc->fullbatt_vchkdrop_ms);
+
+	if (cm->fullbatt_vchk_jiffies_at == 0)
+		cm->fullbatt_vchk_jiffies_at = 1;
+
+out:
+	dev_info(cm->dev, "EVENT_HANDLE: Battery Fully Charged.\n");
+	uevent_notify(cm, default_event_names[CM_EVENT_BATT_FULL]);
+}
+
+/**
+ * battout_handler - Event handler for CM_EVENT_BATT_OUT
+ * @cm: the Charger Manager representing the battery.
+ */
+static void battout_handler(struct charger_manager *cm)
+{
+	if (cm_suspended)
+		cm->cancel_suspend = true;
+
+	if (!is_batt_present(cm)) {
+		dev_emerg(cm->dev, "Battery Pulled Out!\n");
+		uevent_notify(cm, default_event_names[CM_EVENT_BATT_OUT]);
+	} else {
+		uevent_notify(cm, "Battery Reinserted?");
+	}
+}
+
+/**
+ * misc_event_handler - Handler for other evnets
+ * @cm: the Charger Manager representing the battery.
+ * @type: the Charger Manager representing the battery.
+ */
+static void misc_event_handler(struct charger_manager *cm,
+			enum cm_event_types type)
+{
+	if (cm_suspended)
+		cm->cancel_suspend = true;
+
+	if (!delayed_work_pending(&cm_monitor_work) &&
+	    is_polling_required(cm) && cm->desc->polling_interval_ms)
+		schedule_work(&setup_polling);
+	uevent_notify(cm, default_event_names[type]);
+}
+
 static int charger_get_property(struct power_supply *psy,
 		enum power_supply_property psp,
 		union power_supply_propval *val)

@@ -1175,6 +1247,20 @@ static const struct platform_device_id charger_manager_id[] = {
 };
 MODULE_DEVICE_TABLE(platform, charger_manager_id);
 
+static int cm_suspend_noirq(struct device *dev)
+{
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct charger_manager *cm = platform_get_drvdata(pdev);
+
+	if (cm->cancel_suspend) {
+		cm->cancel_suspend = false;
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
 static int cm_suspend_prepare(struct device *dev)
 {
 	struct platform_device *pdev = container_of(dev, struct platform_device,

@@ -1260,11 +1346,13 @@ static void cm_suspend_complete(struct device *dev)
 		queue_delayed_work(cm_wq, &cm->fullbatt_vchk_work,
 				   msecs_to_jiffies(delay));
 	}
+	cm->cancel_suspend = false;
 	uevent_notify(cm, NULL);
 }
 
 static const struct dev_pm_ops charger_manager_pm = {
 	.prepare	= cm_suspend_prepare,
+	.suspend_noirq	= cm_suspend_noirq,
 	.complete	= cm_suspend_complete,
 };
 

@@ -1297,6 +1385,75 @@ static void __exit charger_manager_cleanup(void)
 }
 module_exit(charger_manager_cleanup);
 
+/**
+ * find_power_supply - find the associated power_supply of charger
+ * @cm: the Charger Manager representing the battery
+ * @psy: pointer to instance of charger's power_supply
+ */
+static bool find_power_supply(struct charger_manager *cm,
+			struct power_supply *psy)
+{
+	int i;
+	bool found = false;
+
+	for (i = 0; cm->charger_stat[i]; i++) {
+		if (psy == cm->charger_stat[i]) {
+			found = true;
+			break;
+		}
+	}
+
+	return found;
+}
+
+/**
+ * cm_notify_event - charger driver notify Charger Manager of charger event
+ * @psy: pointer to instance of charger's power_supply
+ * @type: type of charger event
+ * @msg: optional message passed to uevent_notify fuction
+ */
+void cm_notify_event(struct power_supply *psy, enum cm_event_types type,
+		     char *msg)
+{
+	struct charger_manager *cm;
+	bool found_power_supply = false;
+
+	if (psy == NULL)
+		return;
+
+	mutex_lock(&cm_list_mtx);
+	list_for_each_entry(cm, &cm_list, entry) {

drivers/power/charger-manager.c static void __exit charger_manager_cleanup(void) · line 1430

Quoted 5 lines

drivers/power/charger-manager.c +5 -0

+		found_power_supply = find_power_supply(cm, psy);
+		if (found_power_supply)
+			break;
+	}
+	mutex_unlock(&cm_list_mtx);

Why don't you move the entire loop above to find_power_supply()? You won't need the found_power_supply variable in that case.

Quoted 78 lines

drivers/power/charger-manager.c +25 -0

+	if (!found_power_supply)
+		return;
+
+	switch (type) {
+	case CM_EVENT_BATT_FULL:
+		fullbatt_handler(cm);
+		break;
+	case CM_EVENT_BATT_OUT:
+		battout_handler(cm);
+		break;
+	case CM_EVENT_BATT_IN:
+	case CM_EVENT_EXT_PWR_IN_OUT ... CM_EVENT_CHG_START_STOP:
+		misc_event_handler(cm, type);
+		break;
+	case CM_EVENT_UNDESCRIBED:
+	case CM_EVENT_OTHERS:
+		uevent_notify(cm, msg ? msg : default_event_names[type]);
+		break;
+	default:
+		dev_err(cm->dev, "%s type not specified.\n", __func__);
+		break;
+	}
+}
+EXPORT_SYMBOL_GPL(cm_notify_event);
+
 MODULE_AUTHOR("MyungJoo Ham <[email protected]>");
 MODULE_DESCRIPTION("Charger Manager");
 MODULE_LICENSE("GPL");

include/linux/power/charger-manager.h +14 -0

index 78b9865..086917c 100644
@@ -31,6 +31,16 @@ enum polling_modes {
 	CM_POLL_CHARGING_ONLY,
 };
 
+enum cm_event_types {
+	CM_EVENT_UNDESCRIBED = 0,
+	CM_EVENT_BATT_FULL,
+	CM_EVENT_BATT_IN,
+	CM_EVENT_BATT_OUT,
+	CM_EVENT_EXT_PWR_IN_OUT,
+	CM_EVENT_CHG_START_STOP,
+	CM_EVENT_OTHERS,
+};
+
 /**
  * struct charger_global_desc
  * @rtc_name: the name of RTC used to wake up the system from suspend.

@@ -116,6 +126,7 @@ struct charger_desc {
  * @desc: instance of charger_desc
  * @fuel_gauge: power_supply for fuel gauge
  * @charger_stat: array of power_supply for chargers
+ * @cancel_suspend: true if there is a pending charger event
  * @charger_enabled: the state of charger
  * @fullbatt_vchk_jiffies_at:
  *	jiffies at the time full battery check will occur.

@@ -140,6 +151,7 @@ struct charger_manager {
 	struct power_supply *fuel_gauge;
 	struct power_supply **charger_stat;
 
+	bool cancel_suspend;
 	bool charger_enabled;
 
 	unsigned long fullbatt_vchk_jiffies_at;

@@ -159,6 +171,8 @@ struct charger_manager {
 #ifdef CONFIG_CHARGER_MANAGER
 extern int setup_charger_manager(struct charger_global_desc *gd);
 extern bool cm_suspend_again(void);
+extern void cm_notify_event(struct power_supply *psy, enum cm_event_types type,
+			    char *msg); /* msg: optional */
 #else
 static void __maybe_unused setup_charger_manager(struct charger_global_desc *gd)
 { }

@@ -167,6 +181,10 @@ static bool __maybe_unused cm_suspend_again(void)
 {
 	return false;

include/linux/power/charger-manager.h static bool __maybe_unused cm_suspend_again(void) · line 187

Quoted 5 lines

include/linux/power/charger-manager.h +4 -0

 }
+
+static void __maybe_unused cm_notify_event(struct power_supply *psy,
+					   enum cm_event_types type, char *msg)
+{ }

We usually define such things as static inline, in which case the __maybe_unused is not necessary.

include/linux/power/charger-manager.h static bool __maybe_unused cm_suspend_again(void) · line 190

Quoted 4 lines

include/linux/power/charger-manager.h +0 -0

 #endif
 
 #endif /* _CHARGER_MANAGER_H */

Thanks,
Rafael
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