From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754762AbXJ1K1T (ORCPT ); Sun, 28 Oct 2007 06:27:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751545AbXJ1K07 (ORCPT ); Sun, 28 Oct 2007 06:26:59 -0400 Received: from mail01d.mail.t-online.hu ([84.2.42.6]:57829 "EHLO mail01d.mail.t-online.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751262AbXJ1K06 (ORCPT ); Sun, 28 Oct 2007 06:26:58 -0400 Message-ID: <47247113.1020809@freemail.hu> Date: Sun, 28 Oct 2007 12:22:59 +0100 From: =?ISO-8859-2?Q?N=E9meth_M=E1rton?= User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.2) Gecko/20070221 SeaMonkey/1.1.1 MIME-Version: 1.0 To: Richard Purdie CC: Randy Dunlap , Dmitry Torokhov , Rodrigo Pereira , linux-kernel@vger.kernel.org Subject: [PATCH 3/4] leds-clevo-mail: hw accelerated LED blink extension Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Márton Németh 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 --- 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 09:20:07.000000000 +0100 +++ linux-2.6.24-rc1.c/Documentation/leds-class.txt 2007-10-28 09:35:54.000000000 +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 09:13:13.000000000 +0100 +++ linux-2.6.24-rc1.c/drivers/leds/Kconfig 2007-10-28 09:09:45.000000000 +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 09:01:56.000000000 +0100 +++ linux-2.6.24-rc1.c/drivers/leds/ledtrig-timer.c 2007-10-28 08:16:50.000000000 +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)) { + /* no hardware acceleration, blink via timer */ + mod_timer(&timer_data->timer, jiffies + 1); + } + } ret = count; } @@ -143,6 +169,13 @@ static void timer_trig_activate(struct l if (rc) goto err_out_delayon; + /* If there is hardware support for blinking, start one + * user friendly blink rate chosen by the driver. + */ + if (led_cdev->blink_set) + led_cdev->blink_set(led_cdev, + &timer_data->delay_on, &timer_data->delay_off); + return; err_out_delayon: diff -uprN linux-2.6.24-rc1.b/include/linux/leds.h linux-2.6.24-rc1.c/include/linux/leds.h --- linux-2.6.24-rc1.b/include/linux/leds.h 2007-10-28 09:01:56.000000000 +0100 +++ linux-2.6.24-rc1.c/include/linux/leds.h 2007-10-28 10:04:14.000000000 +0100 @@ -37,6 +37,11 @@ struct led_classdev { void (*brightness_set)(struct led_classdev *led_cdev, enum led_brightness brightness); + /* Activate hardware accelerated blink */ + int (*blink_set)(struct led_classdev *led_cdev, + unsigned long *delay_on, + unsigned long *delay_off); + struct device *dev; struct list_head node; /* LED Device list */ char *default_trigger; /* Trigger to use */