(Trying an alternate address for Richard, and adding Andrew to Cc..)
On Thu, Dec 09, 2010 at 02:41:50PM +0100, Janusz Krzysztofik wrote: > This patch extends the LED backlight tirgger driver with an option that > allows > for inverting the trigger output polarity. > > With the invertion option provided, I (ab)use the backlight trigger for > driving a LED that indicates LCD display blank condtition on my Amstrad Delta > videophone. Since the machine has no dedicated power LED, it was not possible > to distinguish if the display was blanked, or the machine was turned off, > without touching it. > > The invert sysfs control is patterned after a similiar function of the GPIO > trigger driver. > > Created and tested against linux-2.6.36-rc5 on Amstrad Delta. > Retested on linux-2.6.37-rc4. > > Signed-off-by: Janusz Krzysztofik <[email protected]> > Cc: Richard Purdie <[email protected]> > --- > > Resent because I still can't see any response received, while yet another > merge window is going to pass away soon. > > Applies cleanly on top of 2.6.37-rc4, so no need for yet another refresh. > Only > tried to clean up the commit message slightly - maybe my English is not good > enough to bother with, if not the code? > > v1 -> v2 changes: > - improve some conditional expressions to be more readable; thanks to Ralph > Corderoy (from e3-hacking) and Lars-Peter Clausen for their suggestions, > - refresh against linux-2.6.36-rc5. > > drivers/leds/ledtrig-backlight.c | 60 > ++++++++++++++++++++++++++++++++++++--- > 1 file changed, 56 insertions(+), 4 deletions(-) > > diff -upr linux-2.6.36-rc5.orig/drivers/leds/ledtrig-backlight.c > linux-2.6.36-rc5/drivers/leds/ledtrig-backlight.c > --- linux-2.6.36-rc5.orig/drivers/leds/ledtrig-backlight.c 2010-09-24 > 15:35:13.000000000 +0200 > +++ linux-2.6.36-rc5/drivers/leds/ledtrig-backlight.c 2010-10-03 > 15:59:49.000000000 +0200 > @@ -26,6 +26,7 @@ struct bl_trig_notifier { > int brightness; > int old_status; > struct notifier_block notifier; > + unsigned invert; > }; > > static int fb_notifier_callback(struct notifier_block *p, > @@ -36,23 +37,63 @@ static int fb_notifier_callback(struct n > struct led_classdev *led = n->led; > struct fb_event *fb_event = data; > int *blank = fb_event->data; > + int new_status = *blank ? BLANK : UNBLANK; > > switch (event) { > case FB_EVENT_BLANK : > - if (*blank && n->old_status == UNBLANK) { > + if (new_status == n->old_status) > + break; > + > + if ((n->old_status == UNBLANK) ^ n->invert) { > n->brightness = led->brightness; > led_set_brightness(led, LED_OFF); > - n->old_status = BLANK; > - } else if (!*blank && n->old_status == BLANK) { > + } else { > led_set_brightness(led, n->brightness); > - n->old_status = UNBLANK; > } > + > + n->old_status = new_status; > + > break; > } > > return 0; > } > > +static ssize_t bl_trig_invert_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct led_classdev *led = dev_get_drvdata(dev); > + struct bl_trig_notifier *n = led->trigger_data; > + > + return sprintf(buf, "%s\n", n->invert ? "yes" : "no"); > +} > + > +static ssize_t bl_trig_invert_store(struct device *dev, > + struct device_attribute *attr, const char *buf, size_t num) > +{ > + struct led_classdev *led = dev_get_drvdata(dev); > + struct bl_trig_notifier *n = led->trigger_data; > + unsigned invert; > + int ret; > + > + ret = sscanf(buf, "%u", &invert); > + if (ret < 1) { > + dev_err(dev, "invalid value\n"); > + return -EINVAL; > + } > + > + n->invert = !!invert; > + > + /* After inverting, we need to update the LED. */ > + if ((n->old_status == BLANK) ^ n->invert) > + led_set_brightness(led, LED_OFF); > + else > + led_set_brightness(led, n->brightness); > + > + return num; > +} > +static DEVICE_ATTR(invert, 0644, bl_trig_invert_show, bl_trig_invert_store); > + > static void bl_trig_activate(struct led_classdev *led) > { > int ret; > @@ -66,6 +107,10 @@ static void bl_trig_activate(struct led_ > return; > } > > + ret = device_create_file(led->dev, &dev_attr_invert); > + if (ret) > + goto err_invert; > + > n->led = led; > n->brightness = led->brightness; > n->old_status = UNBLANK; > @@ -74,6 +119,12 @@ static void bl_trig_activate(struct led_ > ret = fb_register_client(&n->notifier); > if (ret) > dev_err(led->dev, "unable to register backlight trigger\n"); > + > + return; > + > +err_invert: > + led->trigger_data = NULL; > + kfree(n); > } > > static void bl_trig_deactivate(struct led_classdev *led) > @@ -82,6 +133,7 @@ static void bl_trig_deactivate(struct le > (struct bl_trig_notifier *) led->trigger_data; > > if (n) { > + device_remove_file(led->dev, &dev_attr_invert); > fb_unregister_client(&n->notifier); > kfree(n); > } > -- > To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
