From: Marek Szyprowski <m.szyprowski@samsung.com>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-usb <linux-usb@vger.kernel.org>,
Chunfeng Yun <chunfeng.yun@mediatek.com>,
Stefan Agner <stefan@agner.ch>,
Krzysztof Kozlowski <krzk@kernel.org>
Subject: Re: [PATCH] usb: usb3503: Convert to use GPIO descriptors
Date: Mon, 9 Dec 2019 17:33:34 +0100 [thread overview]
Message-ID: <bb1432d3-1fee-9c3d-0ae1-af305deed636@samsung.com> (raw)
In-Reply-To: <CACRpkdZBOFXxm_n+A+Oz=MubkSTKG7aUX+9jonB5vm+_XPK_DA@mail.gmail.com>
Hi Linus,
On 06.12.2019 14:43, Linus Walleij wrote:
> On Fri, Dec 6, 2019 at 12:43 PM Marek Szyprowski
> <m.szyprowski@samsung.com> wrote:
>
>> arch/arm/boot/dts/qcom-mdm9615-wp8548-mangoh-green.dts: invert RESET
>> gpio polarity (to ACTIVE_LOW), not sure about INTN gpio
> AFAICT INTN should be set to ACTIVE_HIGH if it is working with the
> current code in the kernel.
>
> However it is pretty confusing with the "N" at the end of INTN,
> indicating negative polarity. Maybe it means something else,
> I haven't checked the datasheet. Maybe all boards have inverters
> on these lines so they come out active high.
Well, this line is indeed active low. The datasheet names it 'int_n'.
However I think it makes sense to keep it as ACTIVE_HIGH, because the
'n' is already in the gpio name (and dt binding). In contrary, the reset
gpio pin/binding is named without the 'n', thus I want to clarify it as
active low. The datasheet names it 'reset_n'.
If you are okay with this approach, I will send a patchset fixing
polarity in DTS together with your patch converting the driver to gpio
descriptors with the fixup for the reset gpio polarity.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
next prev parent reply other threads:[~2019-12-09 16:33 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20191205145641eucas1p1e3f40dff8a0c8e9ca47425e2370eabbb@eucas1p1.samsung.com>
2019-12-05 14:56 ` [PATCH] usb: usb3503: Convert to use GPIO descriptors Linus Walleij
2019-12-06 7:55 ` Marek Szyprowski
2019-12-06 9:14 ` Marek Szyprowski
2019-12-06 9:56 ` Linus Walleij
2019-12-06 11:42 ` Marek Szyprowski
2019-12-06 13:43 ` Linus Walleij
2019-12-09 16:33 ` Marek Szyprowski [this message]
2019-12-10 23:13 ` Linus Walleij
2019-12-11 8:48 ` Marek Szyprowski
2019-12-06 9:58 ` Linus Walleij
2019-12-06 11:52 ` Marek Szyprowski
2019-12-06 13:21 ` Linus Walleij
2019-12-06 13:33 ` Marek Szyprowski
2019-12-06 13:38 ` Linus Walleij
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