Dan, On 10/28/19 8:36 PM, Dan Murphy wrote: > Jacek > > On 10/28/19 2:22 PM, Jacek Anaszewski wrote: >> Dan, >> >> Thank you for the v15. >> >> On 10/28/19 7:36 PM, Dan Murphy wrote: >>> Introduce a multicolor class that groups colored LEDs >>> within a LED node. >>> >>> The multi color class groups monochrome LEDs and allows controlling two >>> aspects of the final combined color: hue and lightness. The former is >>> controlled via <color>_intensity files and the latter is controlled >>> via brightness file. >>> >>> Signed-off-by: Dan Murphy <dmurphy@xxxxxx> >>> --- >>> .../ABI/testing/sysfs-class-led-multicolor | 36 +++ >>> Documentation/leds/index.rst | 1 + >>> Documentation/leds/leds-class-multicolor.rst | 100 +++++++ >>> drivers/leds/Kconfig | 10 + >>> drivers/leds/Makefile | 1 + >>> drivers/leds/led-class-multicolor.c | 271 ++++++++++++++++++ >>> include/linux/led-class-multicolor.h | 139 +++++++++ >>> 7 files changed, 558 insertions(+) >>> create mode 100644 >>> Documentation/ABI/testing/sysfs-class-led-multicolor >>> create mode 100644 Documentation/leds/leds-class-multicolor.rst >>> create mode 100644 drivers/leds/led-class-multicolor.c >>> create mode 100644 include/linux/led-class-multicolor.h >>> >>> diff --git a/Documentation/ABI/testing/sysfs-class-led-multicolor >>> b/Documentation/ABI/testing/sysfs-class-led-multicolor >>> new file mode 100644 >>> index 000000000000..3d1f9d726c70 >>> --- /dev/null >>> +++ b/Documentation/ABI/testing/sysfs-class-led-multicolor >>> @@ -0,0 +1,36 @@ >>> +What: /sys/class/leds/<led>/brightness >>> +Date: Sept 2019 >>> +KernelVersion: 5.5 >>> +Contact: Dan Murphy <dmurphy@xxxxxx> >>> +Description: read/write >>> + Writing to this file will update all LEDs within the group to a >>> + calculated percentage of what each color LED intensity is set >>> + to. The percentage is calculated for each grouped LED via the >>> + equation below: >>> + >>> + led_brightness = brightness * >>> <color>_intensity/<color>_max_intensity >>> + >>> + For additional details please refer to >>> + Documentation/leds/leds-class-multicolor.rst. >>> + >>> + The value of the color is from 0 to >>> + /sys/class/leds/<led>/max_brightness. >>> + >>> +What: /sys/class/leds/<led>/colors/<color>_intensity >>> +Date: Sept 2019 >>> +KernelVersion: 5.5 >>> +Contact: Dan Murphy <dmurphy@xxxxxx> >>> +Description: read/write >>> + The <color>_intensity file is created based on the color >>> + defined by the registrar of the class. >>> + There is one file per color presented. >>> + >>> + The value of the color is from 0 to >>> + /sys/class/leds/<led>/colors/<color>_max_intensity. >>> + >>> +What: /sys/class/leds/<led>/colors/<color>_max_intensity >>> +Date: Sept 2019 >>> +KernelVersion: 5.5 >>> +Contact: Dan Murphy <dmurphy@xxxxxx> >>> +Description: read only >>> + Maximum intensity level for the LED color. >>> diff --git a/Documentation/leds/index.rst b/Documentation/leds/index.rst >>> index 060f4e485897..bc70c6aa7138 100644 >>> --- a/Documentation/leds/index.rst >>> +++ b/Documentation/leds/index.rst >>> @@ -9,6 +9,7 @@ LEDs >>> leds-class >>> leds-class-flash >>> + leds-class-multicolor >>> ledtrig-oneshot >>> ledtrig-transient >>> ledtrig-usbport >>> diff --git a/Documentation/leds/leds-class-multicolor.rst >>> b/Documentation/leds/leds-class-multicolor.rst >>> new file mode 100644 >>> index 000000000000..c8a224cead51 >>> --- /dev/null >>> +++ b/Documentation/leds/leds-class-multicolor.rst >>> @@ -0,0 +1,100 @@ >>> +==================================== >>> +Multi Color LED handling under Linux >>> +==================================== >>> + >>> +Description >>> +=========== >>> +The multi color class groups monochrome LEDs and allows controlling two >>> +aspects of the final combined color: hue and lightness. The former is >>> +controlled via <color>_intensity files and the latter is controlled >>> +via brightness file. >>> + >>> +For more details on hue and lightness notions please refer to >>> +https://en.wikipedia.org/wiki/CIECAM02. >>> + >>> +Note that intensity files only cache the written value and the actual >>> +change of hardware state occurs upon writing brightness file. This >>> +allows for changing many factors of the perceived color in a virtually >>> +unnoticeable way for the human observer. >>> + >>> +Multicolor Class Control >>> +======================== >>> +The multicolor class presents the LED groups under a directory >>> called "colors". >>> +This directory is a child under the LED parent node created by the >>> led_class >>> +framework. The led_class framework is documented in led-class.rst >>> within this >>> +documentation directory. >>> + >>> +Each colored LED will have two files created under the colors directory >>> +<color>_intensity and <color>_max_intensity. These files will contain >>> +one of LED_COLOR_ID_* definitions from the header >>> +include/dt-bindings/leds/common.h. >>> + >>> +Directory Layout Example >>> +======================== >>> +root:/sys/class/leds/rgb:grouped_leds# ls -lR colors/ >> s/rgb/multicolor/ according to the led_colors[LED_COLOR_ID_MULTI]. > > Ack but this probably would not be multicolor either based on LED node > naming conventions. Why? We still have LED color section in the LED name pattern. And for multicolor LEDs this would make sense. >>> +-rw-r--r-- 1 root root 4096 Jul 7 03:10 blue_intensity >>> +-r--r--r-- 1 root root 4096 Jul 7 03:10 >>> blue_max_intensity >>> +-rw-r--r-- 1 root root 4096 Jul 7 03:10 >>> green_intensity >>> +-r--r--r-- 1 root root 4096 Jul 7 03:10 >>> green_max_intensity >>> +-rw-r--r-- 1 root root 4096 Jul 7 03:10 red_intensity >>> +-r--r--r-- 1 root root 4096 Jul 7 03:10 >>> red_max_intensity >>> + >> [...] >>> +static int led_multicolor_init_color(struct led_classdev_mc >>> *mcled_cdev, >>> + int color_id) >>> +{ >>> + struct led_classdev *led_cdev = mcled_cdev->led_cdev; >>> + struct led_mc_color_entry *mc_priv; >>> + char *intensity_file_name; >>> + char *max_intensity_file_name; >>> + size_t len; >>> + 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; >>> + >>> + sysfs_attr_init(&mc_priv->intensity_attr.attr); >>> + len = strlen(led_colors[color_id]) + strlen(INTENSITY_NAME) + 1; >>> + intensity_file_name = kzalloc(len, GFP_KERNEL); >>> + if (!intensity_file_name) >>> + return -ENOMEM; >>> + >>> + snprintf(intensity_file_name, len, "%s%s", >>> + led_colors[color_id], INTENSITY_NAME); >>> + mc_priv->intensity_attr.attr.name = intensity_file_name; >>> + mc_priv->intensity_attr.attr.mode = 0644; >>> + mc_priv->intensity_attr.store = intensity_store; >>> + mc_priv->intensity_attr.show = intensity_show; >>> + ret = sysfs_add_file_to_group(&led_cdev->dev->kobj, >>> + &mc_priv->intensity_attr.attr, >>> + led_color_group.name); >>> + if (ret) >>> + goto intensity_err_out; >>> + >>> + sysfs_attr_init(&mc_priv->max_intensity_attr.attr); >>> + len = strlen(led_colors[color_id]) + strlen(MAX_INTENSITY_NAME) >>> + 1; >>> + max_intensity_file_name = kzalloc(len, GFP_KERNEL); >>> + if (!max_intensity_file_name) { >>> + ret = -ENOMEM; >>> + goto intensity_err_out; >>> + } >>> + >>> + snprintf(max_intensity_file_name, len, "%s%s", >>> + led_colors[color_id], MAX_INTENSITY_NAME); >>> + mc_priv->max_intensity_attr.attr.name = max_intensity_file_name; >>> + mc_priv->max_intensity_attr.attr.mode = 0444; >>> + mc_priv->max_intensity_attr.show = max_intensity_show; >>> + ret = sysfs_add_file_to_group(&led_cdev->dev->kobj, >>> + &mc_priv->max_intensity_attr.attr, >>> + led_color_group.name); >>> + if (ret) >>> + goto max_intensity_err_out; >>> + >>> + mc_priv->max_intensity = LED_FULL; >>> + list_add_tail(&mc_priv->list, &mcled_cdev->color_list); >> I still would prefer dynamically allocated array here. Also there are >> things I would see differently in the patch 13/19 as already discussed. >> >> Nonetheless I am giving my preliminary ack for this series just to >> give a hint to others to join the review. >> > Replies were given on the 13/19 patch. AFAIR they referred to channel mapping but my request related to replacing list with array was rather more general. We simply don't need a list for fixed set of colors. -- Best regards, Jacek Anaszewski
