Re: [PATCH v10 04/16] leds: multicolor: Introduce a multicolor class definition
From: Dan Murphy
Date: Mon Oct 07 2019 - 07:49:24 EST
Jacek
Thanks for the review
On 10/6/19 10:23 AM, Jacek Anaszewski wrote:
Dan,
Thank you for the update.
On 10/1/19 4:56 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 | 35 +++
Documentation/leds/index.rst | 1 +
Documentation/leds/leds-class-multicolor.rst | 96 +++++++
drivers/leds/Kconfig | 10 +
drivers/leds/Makefile | 1 +
drivers/leds/led-class-multicolor.c | 268 ++++++++++++++++++
include/linux/led-class-multicolor.h | 88 ++++++
7 files changed, 499 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..65cb43de26e6
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-led-multicolor
@@ -0,0 +1,35 @@
+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 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..87a1588d7619
--- /dev/null
+++ b/Documentation/leds/leds-class-multicolor.rst
@@ -0,0 +1,96 @@
+====================================
+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/
+-rw-rwxr-- 1 root root 4096 Jul 7 03:10 red_max_intensity
+--w--wx-w- 1 root root 4096 Jul 7 03:10 red_intensity
+-rw-rwxr-- 1 root root 4096 Jul 7 03:10 green_max_intensity
+--w--wx-w- 1 root root 4096 Jul 7 03:10 green_intensity
+-rw-rwxr-- 1 root root 4096 Jul 7 03:10 blue_max_intensity
+--w--wx-w- 1 root root 4096 Jul 7 03:10 blue_intensity
Now when you have fixed file permissions in LED mc core the
'ls -l' should report them correctly, so this needs to be
updated.
ACK
[...]
+int devm_led_classdev_multicolor_register(struct device *parent,
+ struct led_classdev_mc *mcled_cdev)
+{
+ struct led_classdev_mc **dr;
+ int ret;
+
+ dr = devres_alloc(devm_led_classdev_multicolor_release,
+ sizeof(*dr), GFP_KERNEL);
+ if (!dr)
+ return -ENOMEM;
+
+ ret = led_classdev_multicolor_register(parent, mcled_cdev);
+ if (ret) {
+ devres_free(dr);
+ return ret;
+ }
+
+ *dr = mcled_cdev;
+ devres_add(parent, dr);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devm_led_classdev_multicolor_register);
+
+static int devm_led_classdev_multicolor_match(struct device *dev,
+ void *res, void *data)
+{
+ struct mcled_cdev **p = res;
s/mcled_cdev/led_classdev_mc/
ACK. Fixed in v11
Dan
+
+ if (WARN_ON(!p || !*p))
+ return 0;
+
+ return *p == data;
+}
+
[...]