mfd: stmfx: Disable IRQ in suspend to avoid spurious interrupt

When STMFX supply is stopped, spurious interrupt can occur. To avoid that,
disable the interrupt in suspend before disabling the regulator and
re-enable it at the end of resume.

Fixes: 06252ade91 ("mfd: Add ST Multi-Function eXpander (STMFX) core driver")
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/stmfx.c

@@ -296,6 +296,8 @@ static int stmfx_irq_init(struct i2c_client *client)
 	if (ret)
 		goto irq_exit;
 
+	stmfx->irq = client->irq;
+
 	return 0;
 
 irq_exit:
@@ -486,6 +488,8 @@ static int stmfx_suspend(struct device *dev)
 	if (ret)
 		return ret;
 
+	disable_irq(stmfx->irq);
+
 	if (stmfx->vdd)
 		return regulator_disable(stmfx->vdd);
 
@@ -529,6 +533,8 @@ static int stmfx_resume(struct device *dev)
 	if (ret)
 		return ret;
 
+	enable_irq(stmfx->irq);
+
 	return 0;
 }
 #endif

include/linux/mfd/stmfx.h

@@ -109,6 +109,7 @@ struct stmfx {
 	struct device *dev;
 	struct regmap *map;
 	struct regulator *vdd;
+	int irq;
 	struct irq_domain *irq_domain;
 	struct mutex lock; /* IRQ bus lock */
 	u8 irq_src;