lp8727_charger: Clean up the interrupt handler

For better understanding, function name is changed. (lp8727_intr_config()
is replaced with lp8727_setup_irq().)

The private IRQ number is set when the IRQ is allocated successfully. This
data is used for releasing the IRQ on unloading the driver. Even the IRQ
number is not defined, the driver should be operated. In this case, just
return as 0.

In additional function lp8727_release_irq(), the workqueue is canceled and
the allocated IRQ is released.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

drivers/power/lp8727_charger.c

@@ -90,6 +90,7 @@ struct lp8727_chg {
 	struct lp8727_chg_param *chg_parm;
 	enum lp8727_dev_id devid;
 	unsigned long debounce_jiffies;
+	int irq;
 };
 
 static int lp8727_read_bytes(struct lp8727_chg *pchg, u8 reg, u8 *data, u8 len)
@@ -241,21 +242,39 @@ static irqreturn_t lp8727_isr_func(int irq, void *ptr)
 	return IRQ_HANDLED;
 }
 
-static int lp8727_intr_config(struct lp8727_chg *pchg)
+static int lp8727_setup_irq(struct lp8727_chg *pchg)
 {
+	int ret;
+	int irq = pchg->client->irq;
 	unsigned delay_msec = pchg->pdata ? pchg->pdata->debounce_msec :
 						DEFAULT_DEBOUNCE_MSEC;
 
 	INIT_DELAYED_WORK(&pchg->work, lp8727_delayed_func);
 
-	pchg->debounce_jiffies = msecs_to_jiffies(delay_msec);
+	if (irq <= 0) {
+		dev_warn(pchg->dev, "invalid irq number: %d\n", irq);
+		return 0;
+	}
 
-	return request_threaded_irq(pchg->client->irq,
-				NULL,
-				lp8727_isr_func,
+	ret = request_threaded_irq(irq,	NULL, lp8727_isr_func,
 				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
-				"lp8727_irq",
-				pchg);
+				"lp8727_irq", pchg);
+
+	if (ret)
+		return ret;
+
+	pchg->irq = irq;
+	pchg->debounce_jiffies = msecs_to_jiffies(delay_msec);
+
+	return 0;
+}
+
+static void lp8727_release_irq(struct lp8727_chg *pchg)
+{
+	cancel_delayed_work_sync(&pchg->work);
+
+	if (pchg->irq)
+		free_irq(pchg->irq, pchg);
 }
 
 static enum power_supply_property lp8727_charger_prop[] = {
@@ -462,7 +481,7 @@ static int lp8727_probe(struct i2c_client *cl, const struct i2c_device_id *id)
 		return ret;
 	}
 
-	ret = lp8727_intr_config(pchg);
+	ret = lp8727_setup_irq(pchg);
 	if (ret) {
 		dev_err(pchg->dev, "irq handler err: %d", ret);
 		lp8727_unregister_psy(pchg);
@@ -476,7 +495,7 @@ static int __devexit lp8727_remove(struct i2c_client *cl)
 {
 	struct lp8727_chg *pchg = i2c_get_clientdata(cl);
 
-	free_irq(pchg->client->irq, pchg);
+	lp8727_release_irq(pchg);
 	lp8727_unregister_psy(pchg);
 	return 0;
 }