From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v5 15/16] pwm-backlight: Add rudimentary device tree support
Date: Fri, 30 Mar 2012 13:04:28 -0600 [thread overview]
Message-ID: <4F7603BC.2050300@wwwdotorg.org> (raw)
In-Reply-To: <1332945238-14897-16-git-send-email-thierry.reding@avionic-design.de>
On 03/28/2012 08:33 AM, Thierry Reding wrote:
> This commit adds very basic support for device tree probing. Currently,
> only a PWM and a list of distinct brightness levels can be specified.
> Enabling or disabling backlight power via GPIOs is not yet supported.
>
> Signed-off-by: Thierry Reding <thierry.reding@avionic-design•de>
> diff --git a/Documentation/devicetree/bindings/video/backlight/pwm-backlight b/Documentation/devicetree/bindings/video/backlight/pwm-backlight
> +Required properties:
> + - compatible: "pwm-backlight"
> + - pwms: OF device-tree PWM specification (see PWM binding[0])
> + - num-brightness-levels: number of distinct brightness levels
Do we need the "num-brightness-levels" property at all; it's just the
length of the brightness-levels property.
> + - brightness-levels: Array of distinct brightness levels. Typically these
> + are in the range from 0 to 255, but any range starting at 0 will do.
> + The actual brightness level (PWM duty cycle) will be interpolated
> + from these values. 0 means a 0% duty cycle (darkest/off), while the
> + last value in the array represents a 100% duty cycle (brightest).
...> +Example:
> +
> + backlight {
> + compatible = "pwm-backlight";
> + pwms = <&pwm 0 5000000>;
> +
> + num-brightness-levels = <8>;
> + brightness-levels = <0 4 8 16 32 64 128 255>;
> + default-brightness-level = <6>;
> + };
next prev parent reply other threads:[~2012-03-30 19:04 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-28 14:33 [PATCH v5 00/16] Add PWM framework and device tree support Thierry Reding
2012-03-28 14:33 ` [PATCH v5 01/16] pwm: Add PWM framework support Thierry Reding
2012-03-29 21:41 ` Mark Brown
2012-04-04 6:36 ` Shawn Guo
2012-04-04 6:39 ` Thierry Reding
2012-03-28 14:33 ` [PATCH v5 02/16] pwm: Allow chips to support multiple PWMs Thierry Reding
2012-03-29 21:50 ` Mark Brown
2012-04-04 6:44 ` Shawn Guo
2012-03-28 14:33 ` [PATCH v5 03/16] pwm: Add debugfs interface Thierry Reding
2012-03-29 21:56 ` Mark Brown
2012-04-04 6:47 ` Shawn Guo
2012-03-28 14:33 ` [PATCH v5 04/16] pwm: Add table-based lookup for static mappings Thierry Reding
2012-03-29 22:03 ` Mark Brown
2012-03-30 5:06 ` Thierry Reding
2012-03-30 10:18 ` Mark Brown
2012-03-30 10:38 ` Thierry Reding
2012-03-31 14:30 ` Thierry Reding
2012-04-01 15:20 ` Shawn Guo
2012-04-02 0:47 ` Shawn Guo
2012-04-02 4:50 ` Thierry Reding
2012-03-28 14:33 ` [PATCH v5 05/16] pwm: Add device tree support Thierry Reding
2012-03-28 14:53 ` Arnd Bergmann
2012-03-29 21:47 ` Mark Brown
2012-03-30 6:24 ` Thierry Reding
2012-03-28 14:33 ` [PATCH v5 06/16] ARM: tegra: Fix PWM clock programming Thierry Reding
2012-03-28 14:33 ` [PATCH v5 07/16] ARM: tegra: Provide clock for only one PWM controller Thierry Reding
2012-03-28 14:33 ` [PATCH v5 08/16] pwm: Add NVIDIA Tegra SoC support Thierry Reding
2012-03-30 18:57 ` Stephen Warren
2012-04-04 6:54 ` Shawn Guo
2012-03-28 14:33 ` [PATCH v5 09/16] pwm: tegra: Add device tree support Thierry Reding
2012-03-30 19:00 ` Stephen Warren
2012-04-02 8:37 ` Thierry Reding
2012-04-02 15:42 ` Stephen Warren
2012-04-03 17:55 ` Thierry Reding
2012-04-03 19:43 ` Rob Herring
2012-04-03 23:42 ` Grant Likely
2012-04-04 5:00 ` Thierry Reding
2012-04-04 18:32 ` Stephen Warren
2012-04-07 1:44 ` Grant Likely
2012-03-28 14:33 ` [PATCH v5 10/16] pwm: Move Blackfin PWM driver to PWM framework Thierry Reding
2012-03-28 14:33 ` [PATCH v5 11/16] pwm: Move PXA " Thierry Reding
2012-03-28 14:33 ` [PATCH v5 12/16] ARM i.MX: Move i.MX pwm driver to pwm framework Thierry Reding
2012-03-28 14:33 ` [PATCH v5 13/16] ARM Samsung: Move s3c " Thierry Reding
2012-03-28 14:33 ` [PATCH v5 14/16] ARM vt8500: Move vt8500 " Thierry Reding
2012-03-28 14:33 ` [PATCH v5 15/16] pwm-backlight: Add rudimentary device tree support Thierry Reding
2012-03-30 19:04 ` Stephen Warren [this message]
2012-04-04 18:11 ` Thierry Reding
2012-03-28 14:33 ` [PATCH v5 16/16] pwm: Take over maintainership of the PWM subsystem Thierry Reding
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