Messages in this thread | | | Subject | Re: [PATCH v6 6/9] leds: multicolor: Introduce a multicolor class definition | From | Dan Murphy <> | Date | Wed, 18 Sep 2019 12:09:12 -0500 |
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Greg
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> +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_mc_color_entry *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; > + > + led_color_group.name = led_colors[color_id]; > + ret = sysfs_create_group(data->color_kobj, &led_color_group); > + if (ret) > + return ret; > + > + sysfs_attr_init(&mc_priv->intensity_attr.attr); > + mc_priv->intensity_attr.attr.name = "intensity"; > + mc_priv->intensity_attr.attr.mode = 666; > + mc_priv->intensity_attr.store = intensity_store; > + mc_priv->intensity_attr.show = intensity_show; > + ret = sysfs_add_file_to_group(data->color_kobj, > + &mc_priv->intensity_attr.attr, > + led_color_group.name); > + if (ret) > + return ret; > + > + sysfs_attr_init(&mc_priv->max_intensity_attr.attr); > + mc_priv->max_intensity_attr.attr.name = "max_intensity"; > + mc_priv->max_intensity_attr.attr.mode = 444; > + mc_priv->max_intensity_attr.show = max_intensity_show; > + ret = sysfs_add_file_to_group(data->color_kobj, > + &mc_priv->max_intensity_attr.attr, > + led_color_group.name); > + if (ret) > + goto err_out; > + > + mc_priv->max_intensity = LED_FULL; > + list_add_tail(&mc_priv->list, &data->color_list); > + > +err_out: > + return ret; > +} > + > +static int led_multicolor_init_color_dir(struct led_classdev_mc_data *data, > + struct led_classdev_mc *mcled_cdev) > +{ > + struct led_classdev *led_cdev = mcled_cdev->led_cdev; > + u32 color_id; > + int ret; > + int i, j = 0; > + > + data->color_kobj = kobject_create_and_add("colors", > + &led_cdev->dev->kobj);
We need some guidance here on how to properly create sub directories more then 1 level deep.
In short under the LED class device parent directory we want to create a directory called "colors".
Under that directory we want to create a directory corresponding to the monochrome LED color. Under that directory we have the files to for intensity and max_intensity for the monochrome LED.
We can use the LED class kobject to create the colors directory using the sysfs calls but the issue comes when creating the LED color directory. We don't have a kobj for colors to associate those directories to. The only API we see to use the kobject_create_and_add which then gives us the colors directory kobj.
So the directory structure would look like this which is explained in this patch https://lore.kernel.org/patchwork/patch/1128444/
Directory Layout Example ======================== root:/sys/class/leds/rgb:grouped_leds# ls -lR colors/ colors/: drwxr-xr-x 2 root root 0 Jun 28 20:21 blue rwxr-xr-x 2 root root 0 Jun 28 20:21 green drwxr-xr-x 2 root root 0 Jun 28 20:21 red
colors/blue: -rw------- 1 root root 4096 Jun 28 20:21 intensity -r-------- 1 root root 4096 Jun 28 20:27 max_intensity +colors/green: -rw------- 1 root root 4096 Jun 28 20:22 intensity -r-------- 1 root root 4096 Jun 28 20:27 max_intensity
colors/red: -rw------- 1 root root 4096 Jun 28 20:21 intensity -r-------- 1 root root 4096 Jun 28 20:27 max_intensity
I have reviewed your example code and read your blogs and papers on the subject but nothing really talks about sub-sub directories.
Now if this is a no-no in the kernel that is fine we can adjust but Jacek wanted to get your opinon/guidance on this topic.
Dan
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