Re: [PATCH v5 6/9] leds: multicolor: Introduce a multicolor class definition

From: Jacek Anaszewski <jacek.anaszewski@gmail.com>
To: Dan Murphy <dmurphy@ti.com>, pavel@ucw.cz
Cc: robh+dt@kernel.org, linux-leds@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 6/9] leds: multicolor: Introduce a multicolor class definition
Date: Mon, 16 Sep 2019 22:18:13 +0200	[thread overview]
Message-ID: <43f810ed-f477-1c8e-5f96-ba2c5ef824eb@gmail.com> (raw)
In-Reply-To: <edc6aa22-3a9a-2a99-ccca-1bd3bf07f04b@ti.com>

On 9/16/19 8:34 PM, Dan Murphy wrote:
> Jacek
> 
> On 9/15/19 11:20 AM, Jacek Anaszewski wrote:
>>
>>> +
>>> +static int led_multicolor_init_color(struct led_classdev_mc_data *data,
>>> +                     struct led_classdev_mc *mcled_cdev,
>>> +                     int color_id, int color_index)
>>> +{
>>> +    struct led_classdev *led_cdev = mcled_cdev->led_cdev;
>>> +    struct led_classdev_mc_priv *mc_priv;
>>> +    int ret;
>>> +
>>> +    mc_priv = devm_kzalloc(led_cdev->dev, sizeof(*mc_priv),
>>> GFP_KERNEL);
>>> +    if (!mc_priv)
>>> +        return -ENOMEM;
>>> +
>>> +    mc_priv->led_color_id = color_id;
>>> +    mc_priv->mcled_cdev = mcled_cdev;
>>> +
>>> +    data->led_kobj = kobject_create_and_add(led_colors[color_id],
>>> +                        data->color_kobj);
>> No change here since previous version? What prevents you from following
>> what has been done for drivers/usb/core/ledtrig-usbport.c?
>>
>> Use sysfs_create_group() for creating color dir
>> and sysfs_add_file_to_group() for adding files to it.
> 
> We have nested directories here.  colors is a directory and then the LED
> color is a directory.
> 
> So I am not sure how to create a group under another group without the
> colors directory kobj.
> 
> Wondering if you know of any examples?

Hmm, that indeed seems not to be allowed. kobject_create_and_add()
seems to be the only solution to achieve nested directories.
Nonetheless we will have to first justify the need for that to Greg.

-- 
Best regards,
Jacek Anaszewski