diff mbox series

[RFC,18/18] power: supply: max17040: Do not enforce (incorrect) interrupt trigger type

Message ID 20201210212534.216197-18-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 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@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(-)

Comments

Krzysztof Kozlowski Dec. 11, 2020, 7:47 a.m. UTC | #1
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@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 a/Documentation/devicetree/bindings/power/supply/max17040_battery.txt b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
> 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 b/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


>  	ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> -					max17040_thread_handler, flags,
> +					max17040_thread_handler, IRQF_ONESHOT,
>  					chip->battery->desc->name, chip);
>  
>  	return ret;
> -- 
> 2.25.1
>
Iskren Chernev Dec. 11, 2020, 3:44 p.m. UTC | #2
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@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 
a/Documentation/devicetree/bindings/power/supply/max17040_battery.txt 
b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
 >> 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 
b/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.

Fixing the DT and the drivers will hopefully set a precedent, so future
drivers (when copied/tweaked from existing drivers) will do it right.

Acked-by: Iskren Chernev <iskren.chernev@gmail.com>

 >>      ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 >> -                    max17040_thread_handler, flags,
 >> +                    max17040_thread_handler, IRQF_ONESHOT,
 >>                      chip->battery->desc->name, chip);
 >>
 >>      return ret;
 >> --
 >> 2.25.1
 >>
Krzysztof Kozlowski Dec. 11, 2020, 3:51 p.m. UTC | #3
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@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
> a/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
> b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
> >> 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
> b/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.

Best regards,
Krzysztof
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/power/supply/max17040_battery.txt b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
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 b/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;
 	ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
-					max17040_thread_handler, flags,
+					max17040_thread_handler, IRQF_ONESHOT,
 					chip->battery->desc->name, chip);
 
 	return ret;