[PATCH 5/6] power: bq24190_charger: Check the interrupt status on resume

[Tony Lindgren <tony@atomide.com>]

Some SoCs like omap3 can configure GPIO irqs to use Linux generic
dedicated wakeirq support. If the dedicated wakeirq is configured,
the SoC will use a always-on interrupt controller to produce wake-up
events.

If bq24190 is configured for dedicated wakeirq, we need to check the
interrupt status on PM runtime resume. This is because the Linux
generic wakeirq will call pm_runtime_resume() on the device on a
wakeirq. And as the bq24190 interrupt is falling edge sensitive
and only active for 250 us, there will be no device interrupt seen
by the runtime SoC IRQ controller.

Note that this can cause spurious interrupts on omap3 devices with
bq24190 connected to gpio banks 2 - 5 as there's a glitch on those
pins waking from off mode as listed in "Advisory 1.45". Devices
with this issue should not configure the optional wakeirq interrupt
in the dts file.

Cc: Mark A. Greer <mgreer@animalcreek.com>
Cc: Matt Ranostay <matt@ranostay.consulting>
Cc: Liam Breck <kernel@networkimprov.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/power/supply/bq24190_charger.c | 58 ++++++++++++++++++++++++++++------
 1 file changed, 49 insertions(+), 9 deletions(-)

diff --git a/drivers/power/supply/bq24190_charger.c b/drivers/power/supply/bq24190_charger.c
--- a/drivers/power/supply/bq24190_charger.c
+++ b/drivers/power/supply/bq24190_charger.c
@@ -156,6 +156,8 @@ struct bq24190_dev_info {
 	unsigned int			gpio_int;
 	unsigned int			irq;
 	struct mutex			f_reg_lock;
+	bool				initialized;
+	bool				irq_event;
 	u8				f_reg;
 	u8				ss_reg;
 	u8				watchdog;
@@ -1157,9 +1159,8 @@ static const struct power_supply_desc bq24190_battery_desc = {
 	.property_is_writeable	= bq24190_battery_property_is_writeable,
 };
 
-static irqreturn_t bq24190_irq_handler_thread(int irq, void *data)
+static void bq24190_check_status(struct bq24190_dev_info *bdi)
 {
-	struct bq24190_dev_info *bdi = data;
 	const u8 battery_mask_ss = BQ24190_REG_SS_CHRG_STAT_MASK;
 	const u8 battery_mask_f = BQ24190_REG_F_BAT_FAULT_MASK |
 		BQ24190_REG_F_NTC_FAULT_MASK;
@@ -1167,15 +1168,13 @@ static irqreturn_t bq24190_irq_handler_thread(int irq, void *data)
 	u8 ss_reg = 0, f_reg = 0;
 	int i, ret;
 
-	pm_runtime_get_sync(bdi->dev);
-
 	/* We need to read f_reg twice if fault is set to get correct value */
 	i = 0;
 	do {
 		ret = bq24190_read(bdi, BQ24190_REG_F, &f_reg);
 		if (ret < 0) {
 			dev_err(bdi->dev, "Can't read F reg: %d\n", ret);
-			goto out;
+			return;
 		}
 	} while (f_reg && ++i < 2);
 
@@ -1231,11 +1230,18 @@ static irqreturn_t bq24190_irq_handler_thread(int irq, void *data)
 	if (alert_battery)
 		power_supply_changed(bdi->battery);
 
-out:
-	pm_runtime_put_sync(bdi->dev);
-
 	dev_dbg(bdi->dev, "ss_reg: 0x%02x, f_reg: 0x%02x\n", ss_reg, f_reg);
+}
 
+static irqreturn_t bq24190_irq_handler_thread(int irq, void *data)
+{
+	struct bq24190_dev_info *bdi = data;
+
+	bdi->irq_event = true;
+	pm_runtime_get_sync(bdi->dev);
+	bq24190_check_status(bdi);
+	pm_runtime_put_sync(bdi->dev);
+	bdi->irq_event = false;
 	return IRQ_HANDLED;
 }
 
@@ -1404,6 +1410,7 @@ static int bq24190_probe(struct i2c_client *client,
 	}
 
 	enable_irq(bdi->irq);
+	bdi->initialized = 1;
 
 	return 0;
 
@@ -1439,6 +1446,35 @@ static int bq24190_remove(struct i2c_client *client)
 	return 0;
 }
 
+static int bq24190_runtime_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct bq24190_dev_info *bdi = i2c_get_clientdata(client);
+
+	if (!bdi->initialized)
+		return 0;
+
+	dev_dbg(bdi->dev, "%s\n", __func__);
+
+	return 0;
+}
+
+static int bq24190_runtime_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct bq24190_dev_info *bdi = i2c_get_clientdata(client);
+
+	if (!bdi->initialized)
+		return 0;
+
+	if (!bdi->irq_event) {
+		dev_dbg(bdi->dev, "checking events on possible wakeirq\n");
+		bq24190_check_status(bdi);
+	}
+
+	return 0;
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int bq24190_pm_suspend(struct device *dev)
 {
@@ -1474,7 +1510,11 @@ static int bq24190_pm_resume(struct device *dev)
 }
 #endif
 
-static SIMPLE_DEV_PM_OPS(bq24190_pm_ops, bq24190_pm_suspend, bq24190_pm_resume);
+static const struct dev_pm_ops bq24190_pm_ops = {
+	SET_RUNTIME_PM_OPS(bq24190_runtime_suspend, bq24190_runtime_resume,
+			   NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(bq24190_pm_suspend, bq24190_pm_resume)
+};
 
 /*
  * Only support the bq24190 right now.  The bq24192, bq24192i, and bq24193
-- 
2.11.0