From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Andersson Subject: Re: [PATCH v3 1/3] leds: core: Introduce generic pattern interface Date: Mon, 20 Nov 2017 16:21:02 -0800 Message-ID: <20171121002102.GD28761@minitux> References: <20171115071345.24331-1-bjorn.andersson@linaro.org> <20171115071345.24331-2-bjorn.andersson@linaro.org> <20171115073642.GA21307@kroah.com> <20171120232015.GB13906@amd> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20171120232015.GB13906@amd> Sender: linux-arm-msm-owner@vger.kernel.org To: Pavel Machek Cc: Greg KH , Richard Purdie , Jacek Anaszewski , linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, linux-arm-msm@vger.kernel.org, Rob Herring , Mark Rutland , devicetree@vger.kernel.org, Fenglin Wu List-Id: devicetree@vger.kernel.org On Mon 20 Nov 15:20 PST 2017, Pavel Machek wrote: > On Wed 2017-11-15 08:36:42, Greg KH wrote: > > On Tue, Nov 14, 2017 at 11:13:43PM -0800, Bjorn Andersson wrote: > > > Some LED controllers have support for autonomously controlling > > > brightness over time, according to some preprogrammed pattern or > > > function. > > > > > > This adds a new optional operator that LED class drivers can implement > > > if they support such functionality as well as a new device attribute to > > > configure the pattern for a given LED. > > > > > > Signed-off-by: Bjorn Andersson > > > --- > > > > > > Changes since v2: > > > - None > > > > > > Changes since v1: > > > - New patch, based on discussions following v1 > > > > > > Documentation/ABI/testing/sysfs-class-led | 20 ++++ > > > drivers/leds/led-class.c | 150 ++++++++++++++++++++++++++++++ > > > include/linux/leds.h | 21 +++++ > > > 3 files changed, 191 insertions(+) > > > > > > diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led > > > index 5f67f7ab277b..74a7f5b1f89b 100644 > > > --- a/Documentation/ABI/testing/sysfs-class-led > > > +++ b/Documentation/ABI/testing/sysfs-class-led > > > @@ -61,3 +61,23 @@ Description: > > > gpio and backlight triggers. In case of the backlight trigger, > > > it is useful when driving a LED which is intended to indicate > > > a device in a standby like state. > > > + > > > +What: /sys/class/leds//pattern > > > +Date: July 2017 > > > > That was many months ago :) > > > > > +KernelVersion: 4.14 > > > > And that kernel version is long since released :) > > Yeah, the other problem is it has some interesting format with ":|" > marking repeat, So what would you prefer? We can either add another file ("pattern_repeat"?) that allows you to describe this separately or some other symbol. > and is not really suitable for RGB LEDs... > I can think of two ways to support patterns for a RGB LED; 1) Provide N files for the N channels 2) Make each entry in the suggested pattern file be N brightness values followed by the duration - if we wrap each N-tuple in some symbol (e.g. <>) this would transparently support "set all channels to same brightness value" and per-channel values. The latter being fully compatible with the proposed interface. > I'd really prefer to get driver in first, and add pattern interface > later. > Sure, I can move all the pattern-related code from the driver into a separate patch. Regards, Bjorn