From: Jacek Anaszewski <jacek.anaszewski@gmail.com>
To: Dan Murphy <dmurphy@ti.com>, pavel@ucw.cz
Cc: linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org,
linus.walleij@linaro.org, shawnguo@kernel.org,
"Sascha Hauer" <s.hauer@pengutronix.de>,
"Pengutronix Kernel Team" <kernel@pengutronix.de>,
"Fabio Estevam" <festevam@gmail.com>,
"NXP Linux Team" <linux-imx@nxp.com>,
"Tony Lindgren" <tony@atomide.com>,
"Benoît Cousson" <bcousson@baylibre.com>
Subject: Re: [PATCH v9 01/15] leds: multicolor: Add sysfs interface definition
Date: Wed, 25 Sep 2019 22:58:04 +0200 [thread overview]
Message-ID: <bf3bb1dd-4647-ea9e-784b-e5062afa73d5@gmail.com> (raw)
In-Reply-To: <20190925174616.3714-2-dmurphy@ti.com>
Hi Dan,
Thank you for the v9.
This patch should me melded with 5/15.
On 9/25/19 7:46 PM, Dan Murphy wrote:
> Add a documentation of LED Multicolor LED class specific
> sysfs attributes.
>
> Add multicolor framework class documentation describing the
> usage of the files created.
>
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
> .../ABI/testing/sysfs-class-led-multicolor | 35 +++++++
> Documentation/leds/index.rst | 1 +
> Documentation/leds/leds-class-multicolor.rst | 96 +++++++++++++++++++
> 3 files changed, 132 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-led-multicolor
> create mode 100644 Documentation/leds/leds-class-multicolor.rst
>
> 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@ti.com>
> +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@ti.com>
> +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@ti.com>
> +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
> +
> +Multicolor Class Brightness Control
> +===================================
> +The multiclor class framework will calculate each monochrome LEDs intensity.
> +
> +The brightness level for each LED is calculated based on the color LED
> +intensity setting divided by the color LED max intensity setting multiplied by
> +the requested brightness.
> +
> +led_brightness = brightness * <color>_intensity/<color>_max_intensity
> +
> +Example:
> +Three LEDs are present in the group as defined in "Directory Layout Example"
> +within this document.
> +
> +A user first writes the color LED brightness file with the brightness level that
> +is necessary to achieve a blueish violet output from the RGB LED group.
> +
> +echo 138 > /sys/class/leds/rgb:grouped_leds/red_intensity
> +echo 43 > /sys/class/leds/rgb:grouped_leds/green_intensity
> +echo 226 > /sys/class/leds/rgb:grouped_leds/blue_intensity
> +
> +red -
> + intensity = 138
> + max_intensity = 255
> +green -
> + intensity = 43
> + max_intensity = 255
> +blue -
> + intensity = 226
> + max_intensity = 255
> +
> +The user can control the brightness of that RGB group by writing the parent
> +'brightness' control. Assuming a parent max_brightness of 255 the user may want
> +to dim the LED color group to half. The user would write a value of 128 to the
> +parent brightness file then the values written to each LED will be adjusted
> +base on this value
> +
> +cat /sys/class/leds/rgb:grouped_leds/max_brightness
> +255
> +echo 128 > /sys/class/leds/rgb:grouped_leds/brightness
> +
> +adjusted_red_value = 128 * 138/255 = 69
> +adjusted_green_value = 128 * 43/255 = 21
> +adjusted_blue_value = 128 * 226/255 = 113
> +
> +Reading the parent brightness file will return the current brightness value of
> +the color LED group.
> +
> +cat /sys/class/leds/rgb:grouped_leds/max_brightness
> +255
> +
> +echo 128 > /sys/class/leds/rgb:grouped_leds/brightness
> +
> +cat /sys/class/leds/rgb:grouped_leds/brightness
> +128
>
--
Best regards,
Jacek Anaszewski
next prev parent reply other threads:[~2019-09-25 20:59 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-25 17:46 [PATCH v9 00/15] Multicolor Framework Dan Murphy
2019-09-25 17:46 ` [PATCH v9 01/15] leds: multicolor: Add sysfs interface definition Dan Murphy
2019-09-25 20:58 ` Jacek Anaszewski [this message]
2019-09-26 11:10 ` Pavel Machek
2019-09-26 12:08 ` Dan Murphy
2019-09-25 17:46 ` [PATCH v9 02/15] dt: bindings: Add multicolor class dt bindings documention Dan Murphy
2019-09-25 17:46 ` [PATCH v9 03/15] dt-bindings: leds: Add multicolor ID to the color ID list Dan Murphy
2019-09-25 17:46 ` [PATCH v9 04/15] " Dan Murphy
2019-09-25 17:46 ` [PATCH v9 05/15] leds: multicolor: Introduce a multicolor class definition Dan Murphy
2019-09-25 21:12 ` Jacek Anaszewski
2019-09-26 11:52 ` Dan Murphy
2019-09-28 10:09 ` Jacek Anaszewski
2019-09-28 18:31 ` Jacek Anaszewski
2019-09-25 17:46 ` [PATCH v9 06/15] dt: bindings: lp50xx: Introduce the lp50xx family of RGB drivers Dan Murphy
2019-09-25 17:46 ` [PATCH v9 07/15] leds: lp50xx: Add the LP50XX family of the RGB LED driver Dan Murphy
2019-09-25 21:27 ` Jacek Anaszewski
2019-09-26 11:59 ` Dan Murphy
2019-09-28 10:29 ` Jacek Anaszewski
2019-09-25 17:46 ` [PATCH v9 08/15] dt: bindings: lp55xx: Be consistent in the document with LED Dan Murphy
2019-09-25 21:31 ` Jacek Anaszewski
2019-09-26 12:00 ` Dan Murphy
2019-09-25 17:46 ` [PATCH v9 09/15] dt: bindings: lp55xx: Update binding for Multicolor Framework Dan Murphy
2019-09-25 21:34 ` Jacek Anaszewski
2019-09-26 12:00 ` Dan Murphy
2019-09-25 17:46 ` [PATCH v9 10/15] ARM: dts: n900: Add reg property to the LP5523 channel node Dan Murphy
2019-09-25 17:46 ` [PATCH v9 11/15] ARM: dts: imx6dl-yapp4: Add reg property to the lp5562 " Dan Murphy
2019-09-25 18:00 ` Fabio Estevam
2019-09-25 18:16 ` Dan Murphy
2019-09-25 17:46 ` [PATCH v9 12/15] ARM: dts: ste-href: Add reg property to the LP5521 channel nodes Dan Murphy
2019-10-04 21:30 ` Linus Walleij
2019-09-25 17:46 ` [PATCH v9 13/15] leds: lp55xx: Update the lp55xx to use the multi color framework Dan Murphy
2019-09-25 22:00 ` Jacek Anaszewski
2019-09-26 12:02 ` Dan Murphy
2019-09-29 13:01 ` Jacek Anaszewski
2019-09-30 16:31 ` Dan Murphy
2019-09-30 20:34 ` Dan Murphy
2019-09-25 17:46 ` [PATCH v9 14/15] leds: lp55xx: Fix checkpatch file permissions issues Dan Murphy
2019-09-25 17:46 ` [PATCH v9 15/15] leds: lp5523: Fix checkpatch issues in the code Dan Murphy
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