[RFC 18/18] power: supply: max17040: Do not enforce (incorrect) interrupt trigger type
krzk at kernel.org
Fri Dec 11 10:51:47 EST 2020
On Fri, Dec 11, 2020 at 05:44:26PM +0200, Iskren Chernev wrote:
> On 12/11/20 9:47 AM, Krzysztof Kozlowski wrote:
> > On Thu, Dec 10, 2020 at 10:25:34PM +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 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.
> >> Signed-off-by: Krzysztof Kozlowski <krzk at kernel.org>
> >> ---
> >> This patch should wait till DTS changes are merged, as it relies on
> >> proper Devicetree.
> >> ---
> >> .../devicetree/bindings/power/supply/max17040_battery.txt | 2 +-
> >> drivers/power/supply/max17040_battery.c | 2 +-
> >> 2 files changed, 2 insertions(+), 2 deletions(-)
> >> diff --git
> >> index c802f664b508..194eb9fe574d 100644
> >> --- a/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
> >> +++ b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
> >> @@ -39,7 +39,7 @@ Example:
> >> reg = <0x36>;
> >> maxim,alert-low-soc-level = <10>;
> >> interrupt-parent = <&gpio7>;
> >> - interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
> >> + interrupts = <2 IRQ_TYPE_LEVEL_LOW>;
> >> wakeup-source;
> >> };
> >> diff --git a/drivers/power/supply/max17040_battery.c
> >> index d956c67d5155..f737de0470de 100644
> >> --- a/drivers/power/supply/max17040_battery.c
> >> +++ b/drivers/power/supply/max17040_battery.c
> >> @@ -367,7 +367,7 @@ static int max17040_enable_alert_irq(struct
> max17040_chip *chip)
> >> flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
> > This has to be removed. I will fix it in v2.
> > Best regards,
> > Krzysztof
> I removed the IRQF_TRIGGER_FALLING, tweaked the DT as per the DT patch, and
> it worked on the samsung klte.
> I don't understand how the DT irq flag ends up being used by the kernel. It
> is never explicitly read from DT or passed to interrupt API, only i2c->irq,
> which is a pure int.
The core __setup_irq() calls irqd_get_trigger_type() on IRQ data
matching the IRQ.
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