Re: [RESEND PATCH v3 4/4] leds: Add a multicolor LED driver to group monochromatic LEDs

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
Cc: pavel@ucw.cz, robh+dt@kernel.org,
	sven.schwermer@disruptive-technologies.com,
	krzysztof.kozlowski+dt@linaro.org, johan+linaro@kernel.org,
	marijn.suijten@somainline.org, bjorn.andersson@linaro.org,
	linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, sha@pengutronix.de
Subject: Re: [RESEND PATCH v3 4/4] leds: Add a multicolor LED driver to group monochromatic LEDs
Date: Sat, 17 Sep 2022 11:37:44 +0300	[thread overview]
Message-ID: <CAHp75VeAnJQt7kS8UE+OKcqnScYnmHnVvL+QNW6jR=yF0=oMAA@mail.gmail.com> (raw)
In-Reply-To: <20220917081339.3354075-5-jjhiblot@traphandler.com>

On Sat, Sep 17, 2022 at 11:14 AM Jean-Jacques Hiblot
<jjhiblot@traphandler.com> wrote:
>
> By allowing to group multiple monochrome LED into multicolor LEDs,
> all involved LEDs can be controlled in-sync. This enables using effects
> using triggers, etc.

...

> +config LEDS_GRP_MULTICOLOR
> +       tristate "Multi-color LED grouping support"
> +       help
> +         This option enables support for monochrome LEDs that are
> +         grouped into multicolor LEDs.

What will be the module name in case of "m" choice?

...

> +       struct led_mcg_priv *priv =
> +               container_of(mc_cdev, struct led_mcg_priv, mc_cdev);

One line?

...

> +               /*
> +                * Scale the intensity according the max brightness of the
> +                * monochromatic LED

Usually we put a grammar period at the end of sentences in multi-line comments.

> +                */

...

> +               actual_led_brightness = DIV_ROUND_CLOSEST(
> +                       mono->max_brightness * mc_cdev->subled_info[i].brightness,
> +                       mc_cdev->led_cdev.max_brightness);

Can you fix an indentation, so it won't leave the line ending by open
parenthesis? I believe with the help of a temporary variable it can be
easily achieved.

...

> +       for (;;) {
> +               struct led_classdev *led_cdev;

> +               led_cdev = devm_of_led_get(dev, count);

Why _of_ variant? Please, make this OF independent since it's
pretending to cover not only OF-based systems.

> +               if (IS_ERR(led_cdev)) {

> +                       /* Reached the end of the list ? */
> +                       if (PTR_ERR(led_cdev) == -ENOENT)
> +                               break;

Looks like the above needs an _optional() variant

> +                       return dev_err_probe(dev, PTR_ERR(led_cdev),
> +                                            "Unable to get led #%d", count);
> +               }

...

> +               priv->monochromatics = devm_krealloc(dev, priv->monochromatics,
> +                                       count * sizeof(*priv->monochromatics),
> +                                       GFP_KERNEL);

This needs at minimum to use one of the helpers from overflow.h,
ideally you may implement devm_krealloc_array() as a suitable wrapper
for that.

> +               if (!priv->monochromatics)
> +                       return -ENOMEM;

...

> +       subled = devm_kzalloc(dev, count * sizeof(*subled), GFP_KERNEL);

NIH devm_kcalloc()

> +       if (!subled)
> +               return -ENOMEM;

--
With Best Regards,
Andy Shevchenko