diff mbox series

[RFC,15/18] mfd: max77693: Do not enforce (incorrect) interrupt trigger type

Message ID 20201210212534.216197-15-krzk@kernel.org (mailing list archive)
State New, archived
Headers show
Series [01/18] ARM: dts: exynos: correct fuel gauge interrupt trigger level on GT-I9100 | expand

Commit Message

Krzysztof Kozlowski Dec. 10, 2020, 9:25 p.m. UTC
Interrupt line can be configured on different hardware in different way,
even inverted.  Therefore driver should not enforce specific trigger
type - edge falling - but instead rely on Devicetree to configure it.

The Maxim 77693 datasheet describes the interrupt line as active low
with a requirement of acknowledge from the CPU therefore the edge
falling is not correct.

The interrupt line is shared between PMIC and RTC driver, so using level
sensitive interrupt is here especially important to avoid races.  With
an edge configuration in case if first PMIC signals interrupt followed
shortly after by the RTC, the interrupt might not be yet cleared/acked
thus the second one would not be noticed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

---

This patch should wait till DTS changes are merged, as it relies on
proper Devicetree.
---
 Documentation/devicetree/bindings/mfd/max77693.txt |  2 +-
 drivers/mfd/max77693.c                             | 12 ++++--------
 2 files changed, 5 insertions(+), 9 deletions(-)

Comments

Rob Herring Dec. 21, 2020, 6:46 p.m. UTC | #1
On Thu, 10 Dec 2020 22:25:31 +0100, Krzysztof Kozlowski wrote:
> Interrupt line can be configured on different hardware in different way,
> even inverted.  Therefore driver should not enforce specific trigger
> type - edge falling - but instead rely on Devicetree to configure it.
> 
> The Maxim 77693 datasheet describes the interrupt line as active low
> with a requirement of acknowledge from the CPU therefore the edge
> falling is not correct.
> 
> The interrupt line is shared between PMIC and RTC driver, so using level
> sensitive interrupt is here especially important to avoid races.  With
> an edge configuration in case if first PMIC signals interrupt followed
> shortly after by the RTC, the interrupt might not be yet cleared/acked
> thus the second one would not be noticed.
> 
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> 
> ---
> 
> This patch should wait till DTS changes are merged, as it relies on
> proper Devicetree.
> ---
>  Documentation/devicetree/bindings/mfd/max77693.txt |  2 +-
>  drivers/mfd/max77693.c                             | 12 ++++--------
>  2 files changed, 5 insertions(+), 9 deletions(-)
> 

Acked-by: Rob Herring <robh@kernel.org>
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/mfd/max77693.txt b/Documentation/devicetree/bindings/mfd/max77693.txt
index 0ced96e16c16..1032df14498b 100644
--- a/Documentation/devicetree/bindings/mfd/max77693.txt
+++ b/Documentation/devicetree/bindings/mfd/max77693.txt
@@ -139,7 +139,7 @@  Example:
 		compatible = "maxim,max77693";
 		reg = <0x66>;
 		interrupt-parent = <&gpx1>;
-		interrupts = <5 2>;
+		interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
 
 		regulators {
 			esafeout@1 {
diff --git a/drivers/mfd/max77693.c b/drivers/mfd/max77693.c
index 596ed85cab3b..4e6244e17559 100644
--- a/drivers/mfd/max77693.c
+++ b/drivers/mfd/max77693.c
@@ -222,8 +222,7 @@  static int max77693_i2c_probe(struct i2c_client *i2c,
 	}
 
 	ret = regmap_add_irq_chip(max77693->regmap, max77693->irq,
-				IRQF_ONESHOT | IRQF_SHARED |
-				IRQF_TRIGGER_FALLING, 0,
+				IRQF_ONESHOT | IRQF_SHARED, 0,
 				&max77693_led_irq_chip,
 				&max77693->irq_data_led);
 	if (ret) {
@@ -232,8 +231,7 @@  static int max77693_i2c_probe(struct i2c_client *i2c,
 	}
 
 	ret = regmap_add_irq_chip(max77693->regmap, max77693->irq,
-				IRQF_ONESHOT | IRQF_SHARED |
-				IRQF_TRIGGER_FALLING, 0,
+				IRQF_ONESHOT | IRQF_SHARED, 0,
 				&max77693_topsys_irq_chip,
 				&max77693->irq_data_topsys);
 	if (ret) {
@@ -242,8 +240,7 @@  static int max77693_i2c_probe(struct i2c_client *i2c,
 	}
 
 	ret = regmap_add_irq_chip(max77693->regmap, max77693->irq,
-				IRQF_ONESHOT | IRQF_SHARED |
-				IRQF_TRIGGER_FALLING, 0,
+				IRQF_ONESHOT | IRQF_SHARED, 0,
 				&max77693_charger_irq_chip,
 				&max77693->irq_data_chg);
 	if (ret) {
@@ -252,8 +249,7 @@  static int max77693_i2c_probe(struct i2c_client *i2c,
 	}
 
 	ret = regmap_add_irq_chip(max77693->regmap_muic, max77693->irq,
-				IRQF_ONESHOT | IRQF_SHARED |
-				IRQF_TRIGGER_FALLING, 0,
+				IRQF_ONESHOT | IRQF_SHARED, 0,
 				&max77693_muic_irq_chip,
 				&max77693->irq_data_muic);
 	if (ret) {