mfd: max14577: Do not enforce (incorrect) interrupt trigger type

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 14577/77836 datasheets describe 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 charger 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>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20210602110445.33536-4-krzysztof.kozlowski@canonical.com

diff --git a/Documentation/devicetree/bindings/mfd/max14577.txt b/Documentation/devicetree/bindings/mfd/max14577.txt
index 92070b34675692a0eda1954f57824d0bfe647c71..be11943a0560fc110bc2a8cd7159adb3ee8b70e0 100644 (file)
--- a/Documentation/devicetree/bindings/mfd/max14577.txt
+++ b/Documentation/devicetree/bindings/mfd/max14577.txt
@@ -71,7 +71,7 @@ max14577@25 {
        compatible = "maxim,max14577";
        reg = <0x25>;
        interrupt-parent = <&gpx1>;
-       interrupts = <5 IRQ_TYPE_NONE>;
+       interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
 
        muic: max14577-muic {
                compatible = "maxim,max14577-muic";
@@ -106,7 +106,7 @@ max77836@25 {
        compatible = "maxim,max77836";
        reg = <0x25>;
        interrupt-parent = <&gpx1>;
-       interrupts = <5 IRQ_TYPE_NONE>;
+       interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
 
        muic: max77836-muic {
                compatible = "maxim,max77836-muic";

diff --git a/drivers/mfd/max14577.c b/drivers/mfd/max14577.c
index be185e9d5f16b13ec7d62a1e060a8c1ecdb9eb34..6c487fa14e9c805ddd325d155a4f9efd472508f0 100644 (file)
--- a/drivers/mfd/max14577.c
+++ b/drivers/mfd/max14577.c
@@ -332,7 +332,7 @@ static int max77836_init(struct max14577 *max14577)
        }
 
        ret = regmap_add_irq_chip(max14577->regmap_pmic, max14577->irq,
-                       IRQF_TRIGGER_FALLING | IRQF_ONESHOT | IRQF_SHARED,
+                       IRQF_ONESHOT | IRQF_SHARED,
                        0, &max77836_pmic_irq_chip,
                        &max14577->irq_data_pmic);
        if (ret != 0) {
@@ -418,14 +418,14 @@ static int max14577_i2c_probe(struct i2c_client *i2c,
                irq_chip = &max77836_muic_irq_chip;
                mfd_devs = max77836_devs;
                mfd_devs_size = ARRAY_SIZE(max77836_devs);
-               irq_flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT | IRQF_SHARED;
+               irq_flags = IRQF_ONESHOT | IRQF_SHARED;
                break;
        case MAXIM_DEVICE_TYPE_MAX14577:
        default:
                irq_chip = &max14577_irq_chip;
                mfd_devs = max14577_devs;
                mfd_devs_size = ARRAY_SIZE(max14577_devs);
-               irq_flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
+               irq_flags = IRQF_ONESHOT;
                break;
        }