From: Krzysztof Kozlowski <krzk@kernel.org>
To: Jacek Anaszewski <jacek.anaszewski@gmail.com>,
Pavel Machek <pavel@ucw.cz>, Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Krzysztof Kozlowski <krzk@kernel.org>,
Baolin Wang <baolin.wang@linaro.org>,
linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v3 1/5] dt-bindings: leds: Add pattern initialization from Device Tree
Date: Wed, 12 Dec 2018 12:16:42 +0100 [thread overview]
Message-ID: <1544613406-27026-2-git-send-email-krzk@kernel.org> (raw)
In-Reply-To: <1544613406-27026-1-git-send-email-krzk@kernel.org>
Document new linux,trigger-pattern property for initialization of LED
pattern trigger.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
---
Documentation/devicetree/bindings/leds/common.txt | 36 +++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt
index aa1399814a2a..3daccd4ea8a3 100644
--- a/Documentation/devicetree/bindings/leds/common.txt
+++ b/Documentation/devicetree/bindings/leds/common.txt
@@ -37,6 +37,42 @@ Optional properties for child nodes:
"ide-disk" - LED indicates IDE disk activity (deprecated),
in new implementations use "disk-activity"
"timer" - LED flashes at a fixed, configurable rate
+ "pattern" - LED alters the brightness for the specified duration with one
+ software timer (requires "led-pattern" property)
+
+- led-pattern : String with default pattern for certain triggers. Each trigger
+ may parse this string differently:
+ - one-shot : two numbers specifying delay on and delay off,
+ - timer : two numbers specifying delay on and delay off,
+ - pattern : The pattern is given by a series of tuples, of
+ brightness and duration (ms). The LED is expected to traverse
+ the series and each brightness value for the specified
+ duration. Duration of 0 means brightness should immediately
+ change to new value.
+
+ 1. For gradual dimming, the dimming interval now is set as 50
+ milliseconds. So the tuple with duration less than dimming
+ interval (50ms) is treated as a step change of brightness,
+ i.e. the subsequent brightness will be applied without adding
+ intervening dimming intervals.
+
+ The gradual dimming format of the software pattern values should be:
+ "brightness_1 duration_1 brightness_2 duration_2 brightness_3
+ duration_3 ...".
+ For example "0 1000 255 2000" will make the LED go gradually
+ from zero-intensity to max (255) intensity in 1000
+ milliseconds, then back to zero intensity in 2000
+ milliseconds.
+
+ 2. To make the LED go instantly from one brightness value to
+ another, pattern should use zero-time lengths (the brightness
+ must be same as the previous tuple's). So the format should be:
+ "brightness_1 duration_1 brightness_1 0 brightness_2
+ duration_2 brightness_2 0 ...".
+ For example "0 1000 0 0 255 2000 255 0" will make the LED
+ stay off for one second, then stay at max brightness for two
+ seconds.
+
- led-max-microamp : Maximum LED supply current in microamperes. This property
can be made mandatory for the board configurations
--
2.7.4
next prev parent reply other threads:[~2018-12-12 11:17 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-12 11:16 [PATCH v3 0/5] leds: trigger: Add pattern initialization from Device Tree Krzysztof Kozlowski
2018-12-12 11:16 ` Krzysztof Kozlowski [this message]
2018-12-12 12:32 ` [PATCH v3 1/5] dt-bindings: leds: " Pavel Machek
2018-12-13 8:36 ` Krzysztof Kozlowski
2018-12-17 22:40 ` Rob Herring
2018-12-18 9:06 ` Krzysztof Kozlowski
2018-12-12 11:16 ` [PATCH v3 2/5] leds: Add helper for getting default pattern " Krzysztof Kozlowski
2018-12-12 12:22 ` Pavel Machek
2018-12-13 8:21 ` Krzysztof Kozlowski
2018-12-12 11:16 ` [PATCH v3 3/5] leds: trigger: pattern: Add pattern initialization " Krzysztof Kozlowski
2018-12-12 11:16 ` [PATCH v3 4/5] leds: trigger: oneshot: Add " Krzysztof Kozlowski
2018-12-12 11:16 ` [PATCH v3 5/5] leds: trigger: timer: " Krzysztof Kozlowski
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