From: Pavel Machek <pavel@ucw.cz>
To: Marek Behun <marek.behun@nic.cz>
Cc: Hermes Zhang <chenhui.zhang@axis.com>,
dmurphy@ti.com, robh+dt@kernel.org, linux-leds@vger.kernel.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
chenhuiz@axis.com, lkml@axis.com, kernel@axis.com
Subject: Re: [PATCH 1/2] leds: leds-multi-gpio: Add multiple GPIOs LED driver
Date: Wed, 24 Mar 2021 11:40:16 +0100 [thread overview]
Message-ID: <20210324104016.GA6035@duo.ucw.cz> (raw)
In-Reply-To: <20210324103431.4b945915@thinkpad>
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Hi!
> > From: Hermes Zhang <chenhuiz@axis.com>
> >
> > Introduce a new multiple GPIOs LED driver. This LED will made of
> > multiple GPIOs (up to 8) and will map different brightness to different
> > GPIOs states which defined in dts file.
>
> I wonder how many boards have such LEDs.
>
> Also if it wouldn't be better to expand the original leds-gpio driver.
> Probably depends on how much larger would such expansion make the
> leds-gpio driver.
Let's start with separate.
> Use flexible array members. Allocate with
> devm_kzalloc(dev, struct_size(priv, states, priv->nr_states),
> GFP_KERNEL)
Better yet, assume the brightness is 0..2^(num leds) and avoid this
complexity.
> Again LED_FULL and LED_OFF...
> What about default-state = "keep" ?
>
> Hermes, do you actually have a device that controls LEDs this way? How
> many brightness options do they have?
He has two bits.
> Also I think this functionality could be easily incorporated into the
> existing leds-gpio driver, instead of creating new driver.
> Moreover your driver can control only one LED, so it needs to be
> probed multiple times for multiple LEDs. Meanwhile the leds-gpio driver
> can register multiple LEDs in one probe...
The current version is mostly fine. Let's not overcomplicate it.
Best regards,
Pavel
--
http://www.livejournal.com/~pavelmachek
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next prev parent reply other threads:[~2021-03-24 10:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-24 7:56 [PATCH 0/2] New multiple GPIOs LED driver Hermes Zhang
2021-03-24 7:56 ` [PATCH 1/2] leds: leds-multi-gpio: Add " Hermes Zhang
2021-03-24 10:34 ` Marek Behun
2021-03-24 10:40 ` Pavel Machek [this message]
2021-03-24 10:42 ` Pavel Machek
2021-03-25 6:04 ` Hermes Zhang
2021-03-25 12:26 ` Marek Behun
2021-03-24 10:41 ` Pavel Machek
2021-03-24 7:56 ` [PATCH 2/2] dt-binding: leds: Document leds-multi-gpio bindings Hermes Zhang
2021-03-24 10:40 ` Marek Behun
2021-03-25 5:27 ` Vesa Jääskeläinen
2021-03-25 18:41 ` Pavel Machek
2021-03-28 20:46 ` Vesa Jääskeläinen
2021-03-24 10:42 ` [PATCH 0/2] New multiple GPIOs LED driver Marek Behun
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