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Date:   Tue, 3 Apr 2018 12:49:08 +0200
From:   Pavel Machek <pavel@ucw.cz>
To:     Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Cc:     Sebastian Reichel <sre@kernel.org>, Milo Kim <Milo.Kim@ti.com>,
        Lee Jones <lee.jones@linaro.org>,
        Daniel Thompson <daniel.thompson@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Tony Lindgren <tony@atomide.com>,
        Jingoo Han <jingoohan1@gmail.com>,
        Mark Rutland <mark.rutland@arm.com>,
        linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-omap@vger.kernel.org
Subject: Re: [PATCHv4 08/10] backlight: add TI LMU backlight driver
Message-ID: <20180403104908.GD6758@amd>
References: <20180330172414.26575-1-sebastian.reichel@collabora.co.uk>
 <20180330172414.26575-9-sebastian.reichel@collabora.co.uk>
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Hi!

> +enum ti_lmu_bl_type {
> +	TI_LMU_BL,  /* backlight userspace interface */
> +	TI_LMU_LED, /* led userspace interface */
> +};
=2E..
> +static int ti_lmu_bl_add_device(struct ti_lmu_bank *lmu_bank)
> +{
> +	switch (lmu_bank->type) {
> +	case TI_LMU_BL:
> +		return ti_lmu_bl_register_backlight(lmu_bank);
> +	case TI_LMU_LED:
> +		return ti_lmu_bl_register_led(lmu_bank);
> +	default:
> +		return -EINVAL;
> +	}
> +}

Ok, this is somehow unusual/crazy. Single driver with two interfaces.

Do we need the LED interface for something?

If yes, I believe reasonable solution would be to always provide LED
interface, and then have "backlight-trigger" which that would provide
backlight interface for arbitrary LED.

Thanks,
									Pavel
--=20
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo=
g.html

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