[PATCH 3/4] leds-clevo-mail: hw accelerated LED blink extension
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-2.6.24-rc1.b/Documentation/leds-class.txt linux-2.6.24-rc1.c/Documentation/leds-class.txt --- linux-2.6.24-rc1.b/Documentation/leds-class.txt 2007-10-28 09:20:07.0 +0100 +++ linux-2.6.24-rc1.c/Documentation/leds-class.txt 2007-10-28 09:35:54.0 +0100 @@ -49,6 +49,27 @@ 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 ). 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. + +The blink_set() function should choose a user friendly blinking +value if it is called with *delay_on==0 && *delay_off==0 parameters. In +this case the driver should give back the chosen value through delay_on +and delay_off parameters to the leds subsystem. + +Any call to the brightness_set() callback function should cancel the +previously programmed hardware blinking function so setting the brightness +to 0 can also cancel the blinking of the LED. + + Known Issues @@ -57,10 +78,6 @@ would cause nightmare dependency issues. compared to the benefits the simple trigger functionality brings. The rest of the LED subsystem can be modular. -Some leds can be programmed to flash in hardware. As this isn't a generic -LED device property, this should be exported as a device specific sysfs -attribute rather than part of the class if this functionality is required. - Future Development == diff -uprN linux-2.6.24-rc1.b/drivers/leds/Kconfig linux-2.6.24-rc1.c/drivers/leds/Kconfig --- linux-2.6.24-rc1.b/drivers/leds/Kconfig 2007-10-28 09:13:13.0 +0100 +++ linux-2.6.24-rc1.c/drivers/leds/Kconfig 2007-10-28 09:09:45.0 +0100 @@ -152,7 +152,11 @@ config LEDS_TRIGGER_TIMER depends on LEDS_TRIGGERS help This allows LEDs to be controlled by a programmable timer - via sysfs. If unsure, say Y. + via sysfs. Some LED hardware can be programmed to start + blinking the LED without any further software interaction. + For more details read Documentation/leds-class.txt. + + If unsure, say Y. config LEDS_TRIGGER_IDE_DISK bool "LED IDE Disk Trigger" diff -uprN linux-2.6.24-rc1.b/drivers/leds/ledtrig-timer.c linux-2.6.24-rc1.c/drivers/leds/ledtrig-timer.c --- linux-2.6.24-rc1.b/drivers/leds/ledtrig-timer.c 2007-10-28 09:01:56.0 +0100 +++ linux-2.6.24-rc1.c/drivers/leds/ledtrig-timer.c 2007-10-28 08:16:50.0 +0100 @@ -77,8 +77,21 @@ static ssize_t led_delay_on_store(struct count++; if (count == size) { - timer_data->delay_on = state; - mod_timer(_data->timer, jiffies + 1); + if (timer_data->delay_on != state) { + /* the new value differs from the previous */ + timer_data->delay_on = state; + + /* deactivate previous settings */ + del_timer_sync(_data->timer); + + /* try to activate hardware acceleration, if any */ + if (!led_cdev->blink_set || + led_cdev->blink_set(led_cdev, + _data->delay_on, _data->delay_off)) { + /* no hardware acceleration, blink via timer */ + mod_timer(_data->timer, jiffies + 1); + } + } ret = count; } @@ -110,8 +123,21 @@ static ssize_t led_delay_off_store(struc count++; if (count == size) { - timer_data->delay_off = state; - mod_timer(_data->timer, jiffies + 1); + if (timer_data->delay_off != state) { + /* the new value differs from the previous */ + timer_data->delay_off = state; + + /* deactivate previous settings */ + del_timer_sync(_data->timer); + + /* try to activate hardware acceleration, if any */ + if (!led_cdev->blink_set || + led_cdev->blink_set(led_cdev, + _data->delay_on, _data->delay_off)) { + /* no hardware
[PATCH 3/4] leds-clevo-mail: hw accelerated LED blink extension
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-2.6.24-rc1.b/Documentation/leds-class.txt linux-2.6.24-rc1.c/Documentation/leds-class.txt --- linux-2.6.24-rc1.b/Documentation/leds-class.txt 2007-10-28 09:20:07.0 +0100 +++ linux-2.6.24-rc1.c/Documentation/leds-class.txt 2007-10-28 09:35:54.0 +0100 @@ -49,6 +49,27 @@ 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. + +The blink_set() function should choose a user friendly blinking +value if it is called with *delay_on==0 *delay_off==0 parameters. In +this case the driver should give back the chosen value through delay_on +and delay_off parameters to the leds subsystem. + +Any call to the brightness_set() callback function should cancel the +previously programmed hardware blinking function so setting the brightness +to 0 can also cancel the blinking of the LED. + + Known Issues @@ -57,10 +78,6 @@ would cause nightmare dependency issues. compared to the benefits the simple trigger functionality brings. The rest of the LED subsystem can be modular. -Some leds can be programmed to flash in hardware. As this isn't a generic -LED device property, this should be exported as a device specific sysfs -attribute rather than part of the class if this functionality is required. - Future Development == diff -uprN linux-2.6.24-rc1.b/drivers/leds/Kconfig linux-2.6.24-rc1.c/drivers/leds/Kconfig --- linux-2.6.24-rc1.b/drivers/leds/Kconfig 2007-10-28 09:13:13.0 +0100 +++ linux-2.6.24-rc1.c/drivers/leds/Kconfig 2007-10-28 09:09:45.0 +0100 @@ -152,7 +152,11 @@ config LEDS_TRIGGER_TIMER depends on LEDS_TRIGGERS help This allows LEDs to be controlled by a programmable timer - via sysfs. If unsure, say Y. + via sysfs. Some LED hardware can be programmed to start + blinking the LED without any further software interaction. + For more details read Documentation/leds-class.txt. + + If unsure, say Y. config LEDS_TRIGGER_IDE_DISK bool LED IDE Disk Trigger diff -uprN linux-2.6.24-rc1.b/drivers/leds/ledtrig-timer.c linux-2.6.24-rc1.c/drivers/leds/ledtrig-timer.c --- linux-2.6.24-rc1.b/drivers/leds/ledtrig-timer.c 2007-10-28 09:01:56.0 +0100 +++ linux-2.6.24-rc1.c/drivers/leds/ledtrig-timer.c 2007-10-28 08:16:50.0 +0100 @@ -77,8 +77,21 @@ static ssize_t led_delay_on_store(struct count++; if (count == size) { - timer_data-delay_on = state; - mod_timer(timer_data-timer, jiffies + 1); + if (timer_data-delay_on != state) { + /* the new value differs from the previous */ + timer_data-delay_on = state; + + /* deactivate previous settings */ + del_timer_sync(timer_data-timer); + + /* try to activate hardware acceleration, if any */ + if (!led_cdev-blink_set || + led_cdev-blink_set(led_cdev, + timer_data-delay_on, timer_data-delay_off)) { + /* no hardware acceleration, blink via timer */ + mod_timer(timer_data-timer, jiffies + 1); + } + } ret = count; } @@ -110,8 +123,21 @@ static ssize_t led_delay_off_store(struc count++; if (count == size) { - timer_data-delay_off = state; - mod_timer(timer_data-timer, jiffies + 1); + if (timer_data-delay_off != state) { + /* the new value differs from the previous */ + timer_data-delay_off = state; + + /* deactivate previous settings */ + del_timer_sync(timer_data-timer); + + /* try to activate hardware acceleration, if any */ + if (!led_cdev-blink_set || + led_cdev-blink_set(led_cdev, + timer_data-delay_on, timer_data-delay_off)) { +