power: supply: act8945a_charger: Add status change update support

Add the charger status change interrupt support, it will report
the power supply changed event.

This interrupt is generated by one of the conditions as below:
 - the state machine jumps out of or into the EOC state
 - the CHGIN input voltage goes out of or into the valid range.
 - the battery temperature goes out of or into the valid range.
 - the PRECHARGE time-out occurs.
 - the total charge time-out occurs.
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

drivers/power/supply/act8945a_charger.c

@@ -10,9 +10,11 @@
  * published by the Free Software Foundation.
  *
  */
+#include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
+#include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
 #include <linux/regmap.h>
@@ -75,7 +77,11 @@ static const char *act8945a_charger_manufacturer = "Active-semi";
 #define APCH_STATE_CSTATE_PRE		0x03
 
 struct act8945a_charger {
+	struct power_supply *psy;
 	struct regmap *regmap;
+	struct work_struct work;
+
+	bool init_done;
 };
 
 static int act8945a_get_charger_state(struct regmap *regmap, int *val)
@@ -252,6 +258,47 @@ static const struct power_supply_desc act8945a_charger_desc = {
 	.num_properties	= ARRAY_SIZE(act8945a_charger_props),
 };
 
+static int act8945a_enable_interrupt(struct act8945a_charger *charger)
+{
+	struct regmap *regmap = charger->regmap;
+	unsigned char ctrl;
+	int ret;
+
+	ctrl = APCH_CTRL_CHGEOCOUT | APCH_CTRL_CHGEOCIN |
+	       APCH_CTRL_INDIS | APCH_CTRL_INCON |
+	       APCH_CTRL_TEMPOUT | APCH_CTRL_TEMPIN |
+	       APCH_CTRL_TIMRPRE | APCH_CTRL_TIMRTOT;
+	ret = regmap_write(regmap, ACT8945A_APCH_CTRL, ctrl);
+	if (ret)
+		return ret;
+
+	ctrl = APCH_STATUS_CHGSTAT | APCH_STATUS_INSTAT |
+	       APCH_STATUS_TEMPSTAT | APCH_STATUS_TIMRSTAT;
+	ret = regmap_write(regmap, ACT8945A_APCH_STATUS, ctrl);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void act8945a_work(struct work_struct *work)
+{
+	struct act8945a_charger *charger =
+			container_of(work, struct act8945a_charger, work);
+
+	power_supply_changed(charger->psy);
+}
+
+static irqreturn_t act8945a_status_changed(int irq, void *dev_id)
+{
+	struct act8945a_charger *charger = dev_id;
+
+	if (charger->init_done)
+		schedule_work(&charger->work);
+
+	return IRQ_HANDLED;
+}
+
 #define DEFAULT_TOTAL_TIME_OUT		3
 #define DEFAULT_PRE_TIME_OUT		40
 #define DEFAULT_INPUT_OVP_THRESHOLD	6600
@@ -362,9 +409,8 @@ static int act8945a_charger_config(struct device *dev,
 static int act8945a_charger_probe(struct platform_device *pdev)
 {
 	struct act8945a_charger *charger;
-	struct power_supply *psy;
 	struct power_supply_config psy_cfg = {};
-	int ret;
+	int irq, ret;
 
 	charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
 	if (!charger)
@@ -380,17 +426,51 @@ static int act8945a_charger_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	irq = of_irq_get(pdev->dev.of_node, 0);
+	if (irq == -EPROBE_DEFER) {
+		dev_err(&pdev->dev, "failed to find IRQ number\n");
+		return -EPROBE_DEFER;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq, act8945a_status_changed,
+			       IRQF_TRIGGER_FALLING, "act8945a_interrupt",
+			       charger);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to request nIRQ pin IRQ\n");
+		return ret;
+	}
+
 	psy_cfg.of_node	= pdev->dev.of_node;
 	psy_cfg.drv_data = charger;
 
-	psy = devm_power_supply_register(&pdev->dev,
+	charger->psy = devm_power_supply_register(&pdev->dev,
 						  &act8945a_charger_desc,
 						  &psy_cfg);
-	if (IS_ERR(psy)) {
+	if (IS_ERR(charger->psy)) {
 		dev_err(&pdev->dev, "failed to register power supply\n");
-		return PTR_ERR(psy);
+		return PTR_ERR(charger->psy);
 	}
 
+	platform_set_drvdata(pdev, charger);
+
+	INIT_WORK(&charger->work, act8945a_work);
+
+	ret = act8945a_enable_interrupt(charger);
+	if (ret)
+		return -EIO;
+
+	charger->init_done = true;
+
+	return 0;
+}
+
+static int act8945a_charger_remove(struct platform_device *pdev)
+{
+	struct act8945a_charger *charger = platform_get_drvdata(pdev);
+
+	charger->init_done = false;
+	cancel_work_sync(&charger->work);
+
 	return 0;
 }
 
@@ -399,6 +479,7 @@ static struct platform_driver act8945a_charger_driver = {
 		.name = "act8945a-charger",
 	},
 	.probe	= act8945a_charger_probe,
+	.remove = act8945a_charger_remove,
 };
 module_platform_driver(act8945a_charger_driver);