lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 16 Feb 2017 22:15:29 +0100 From: Frieder Schrempf <frieder.schrempf@...eet.de> To: David Lechner <david@...hnology.com>, Dmitry Torokhov <dmitry.torokhov@...il.com> CC: <robh@...nel.org>, <pawel.moll@....com>, <ijc+devicetree@...lion.org.uk>, <galak@...eaurora.org>, <luis@...ethencourt.com>, <linux-input@...r.kernel.org>, <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org> Subject: Re: [PATCH v3 0/3] input: pwm-beeper: add feature to set volume level Hello David, On 20.01.2017 20:11, David Lechner wrote: > On 01/19/2017 03:37 PM, Dmitry Torokhov wrote: >> On Thu, Jan 19, 2017 at 04:24:07PM +0100, Frieder Schrempf wrote: >>> Make the driver accept switching volume levels via sysfs. >>> This can be helpful if the beep/bell sound intensity needs >>> to be adapted to the environment of the device. >>> >>> The number of volume levels available and their values can >>> be specified via device tree (similar to pwm-backlight). >>> >>> The volume adjustment is done by changing the duty cycle of >>> the pwm signal. >> >> I wonder how this all will mesh up with beepers that have dedicated >> amplifiers (support is being added by David Lechner). > > This will work very well with it. I fact, it is a feature I would like > to have but I was not sure about a good way to implement it. Please Cc: > me on future revisions of this series and I will be glad to test it. I have just send v4. > > One thing that would be nice would be for a more generic way to change > the volume from userspace. Having a sysfs attribute on the platform > device will work, but it requires very specific knowledge from any > userspace program that wants to control the volume. Would it be possible > to add an alsa mixer volume control or something like that? An alsa mixer control for the pwm-beeper volume sounds nice, but unfortunately I have no idea how one would implement this, or if this is even possible. >
Powered by blists - more mailing lists