On Sun, 2007-10-21 at 14:54 +0200, Németh Márton wrote:
> From: Márton Németh <[email protected]>
>
> Extends the leds subsystem with a blink_set() callback function which can
> be optionally implemented by a LED driver. If implemented, the driver can use
> the hardware acceleration for blinking a LED.
>
> Signed-off-by: Márton Németh <[email protected]>
> ---
> diff -uprN linux-2.6.23.orig/Documentation/leds-class.txt linux-2.6.23/Documentation/leds-class.txt
> --- linux-2.6.23.orig/Documentation/leds-class.txt 2007-10-09 22:31:38.000000000 +0200
> +++ linux-2.6.23/Documentation/leds-class.txt 2007-10-21 10:45:35.000000000 +0200
> @@ -47,6 +49,19 @@ overhead, I suggest these become part of
> above leaves scope for further attributes should they be needed.
>
>
> +
> +Hardware accelerated blink of LEDs
> +==================================
> +
> +Some LEDs can be programmed to blink without any CPU interaction. To
> +support this feature, a LED driver can optionally implement the
> +blink_set() function (see <linux/leds.h>). If implemeted, the
> +ledtrig-timer tries to use it. The blink_set() function should return
> +0 if the blink setting is supported, or -EINVAL otherwise, which means
> +that the LED will be turned on and off from software by the leds
> +subsystem.
Hardware acceleration of the timer triggers is great to see and worst
case I'll happily apply this patch to the LED tree, thanks.
Before I do, I did wonder if we should enhance the meaning of the
set_blink function a bit. If set_blink is called with delay_on = 0,
delay_off = 0 it could mean "blink with some user friendly value,
hardware assisted". The use for this would be a more generic blink
trigger where you wouldn't need to know about magically hardware
assisted values for blinking, it would simply make an LED blink in a
hardware assisted way.
We also need to document that the brightness_set overrides any blinking
which may or may not be active (which is implied in your driver).
Cheers,
Richard
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
