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

From: Krzysztof Kozlowski <krzk@kernel.org>
To: Chanwoo Choi <cw00.choi@samsung.com>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	Lee Jones <lee.jones@linaro.org>,
	Sebastian Reichel <sre@kernel.org>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>, Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Alessandro Zummo <a.zummo@towertech.it>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org,
	devicetree@vger.kernel.org, linux-pm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-rtc@vger.kernel.org
Cc: Iskren Chernev <iskren.chernev@gmail.com>,
	Matheus Castello <matheus@castello.eng.br>,
	Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>,
	Angus Ainslie <angus@akkea.ca>,
	Hans de Goede <hdegoede@redhat.com>
Subject: Re: [RFC 18/18] power: supply: max17040: Do not enforce (incorrect) interrupt trigger type
Date: Fri, 11 Dec 2020 08:47:55 +0100	[thread overview]
Message-ID: <20201211074755.GA4346@kozik-lap> (raw)
In-Reply-To: <20201210212534.216197-18-krzk@kernel.org>

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
> 