From: Stephen Warren <swarren@wwwdotorg.org>
To: Alexandre Courbot <acourbot@nvidia.com>
Cc: Stephen Warren <swarren@nvidia.com>,
Thierry Reding <thierry.reding@avionic-design.de>,
Simon Glass <sjg@chromium.org>,
Grant Likely <grant.likely@secretlab.ca>,
Rob Herring <rob.herring@calxeda.com>,
Mark Brown <broonie@opensource.wolfsonmicro.com>,
Anton Vorontsov <cbou@mail.ru>,
David Woodhouse <dwmw2@infradead.org>,
Arnd Bergmann <arnd@arndb.de>,
Leela Krishna Amudala <leelakrishna.a@gmail.com>,
linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fbdev@vger.kernel.org, devicetree-discuss@lists.ozlabs.org,
linux-doc@vger.kernel.org
Subject: Re: [PATCH v4 2/3] pwm_backlight: use power sequences
Date: Thu, 16 Aug 2012 12:42:24 -0600 [thread overview]
Message-ID: <502D3F10.1020509@wwwdotorg.org> (raw)
In-Reply-To: <1345097337-24170-3-git-send-email-acourbot@nvidia.com>
On 08/16/2012 12:08 AM, Alexandre Courbot wrote:
> Make use of the power sequences specified in the device tree or platform
> data to control how the backlight is powered on and off.
> +++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
> Required properties:
> - compatible: "pwm-backlight"
> - - pwms: OF device-tree PWM specification (see PWM binding[0])
> - 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
> @@ -10,19 +9,72 @@ Required properties:
> last value in the array represents a 100% duty cycle (brightest).
> - default-brightness-level: the default brightness level (index into the
> array defined by the "brightness-levels" property)
> + - pwms: OF device-tree PWM specification (see PWM binding[0]). Exactly one PWM
> + must be specified
There's probably no need to move that entry just to change it?
> Optional properties:
> - - pwm-names: a list of names for the PWM devices specified in the
> - "pwms" property (see PWM binding[0])
> + - *-supply: regulators used within a power sequence
> + - *-gpio: GPIOs used within a power sequence
I don't think these really warrant mentioning here; such properties are
part of the standard regulator and GPIO bindings, and are required as a
side-effect of a power sequence using a resource of those types, rather
than being something actively defined or needed directly by the
pwm-backlight binding.
> + - pwm-names: name for the PWM device specified in the "pwms" property (see PWM
> + binding[0]). Necessary if power sequences are used
> + - power-on-sequence: Power sequence (see Power sequences[1]) used to bring the
> + backlight on. This sequence must reference the PWM specified in the pwms
> + property by its name. It can also reference other resources supported by
> + the power sequences mechanism
> + - power-off-sequence: Power sequence (see Power sequences[1]) used to bring
> + the backlight off. This sequence must reference the PWM specified in the
> + pwms property by its name. It can also reference other resources supported
> + by the power sequences mechanism
For these two, I would personally simply say that the pwm-backlight
binding requires that two power sequences named "on" and "off" must
exists, and are to defined according to [1].
> [0]: Documentation/devicetree/bindings/pwm/pwm.txt
> +[1]: Documentation/devicetree/bindings/power_seq/power_seq.txt
next prev parent reply other threads:[~2012-08-16 18:42 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-16 6:08 [PATCH v4 0/3] Runtime Interpreted Power Sequences Alexandre Courbot
2012-08-16 6:08 ` [PATCH v4 1/3] " Alexandre Courbot
2012-08-16 7:42 ` Thierry Reding
2012-08-16 9:19 ` Alex Courbot
2012-08-16 9:52 ` Thierry Reding
2012-08-16 10:33 ` Alex Courbot
2012-08-16 10:52 ` Thierry Reding
2012-08-16 14:14 ` Mark Brown
2012-08-16 18:38 ` Stephen Warren
2012-08-16 18:47 ` Mark Brown
2012-08-16 18:57 ` Stephen Warren
2012-08-16 19:35 ` Stephen Warren
2012-08-16 19:49 ` Thierry Reding
2012-08-16 21:10 ` Mitch Bradley
2012-08-17 23:04 ` Mark Brown
2012-08-17 8:52 ` Alex Courbot
2012-08-21 7:44 ` Tomi Valkeinen
2012-08-21 8:22 ` Alex Courbot
2012-08-21 8:33 ` Thierry Reding
2012-08-21 8:53 ` Alex Courbot
2012-08-21 8:57 ` Tomi Valkeinen
2012-08-21 9:13 ` Thierry Reding
2012-08-21 9:54 ` Tomi Valkeinen
2012-08-21 16:57 ` Mark Brown
2012-08-22 5:42 ` Thierry Reding
2012-08-24 9:24 ` Alex Courbot
2012-08-24 10:34 ` Tomi Valkeinen
2012-08-16 6:08 ` [PATCH v4 2/3] pwm_backlight: use power sequences Alexandre Courbot
2012-08-16 18:42 ` Stephen Warren [this message]
2012-08-16 6:08 ` [PATCH v4 3/3] tegra: add pwm backlight device tree nodes Alexandre Courbot
2012-08-16 18:45 ` Stephen Warren
2012-08-16 21:47 ` [PATCH v4 0/3] Runtime Interpreted Power Sequences Rafael J. Wysocki
2012-08-17 8:54 ` Alex Courbot
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