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path: root/include/linux/leds.h
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2016-01-04leds: core: add managed version of led_trigger_registerHeiner Kallweit1-0/+2
Complementing devm_led_classdev_register add a managed version of led_trigger_register. I omit a managed version of led_classdev_unregister as the equivalent devm_led_classdev_unregister isn't used in the kernel as of today. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
2016-01-04leds: core: Drivers shouldn't enforce SYNC/ASYNC brightness settingJacek Anaszewski1-3/+16
This patch removes SET_BRIGHTNESS_ASYNC and SET_BRIGHTNESS_SYNC flags. led_set_brightness() now calls led_set_brightness_nosleep() instead of choosing between sync and async op basing on the flags defined by the driver. From now on, if a user wants to make sure that brightness will be set synchronously, they have to use led_set_brightness_sync() API. It is now being made publicly available since it has become apparent that it is a caller who should decide whether brightness is to be set in a synchronous or an asynchronous way. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
2016-01-04leds: core: Use set_brightness_work for the blocking opJacek Anaszewski1-1/+1
This patch makes LED core capable of setting brightness for drivers that implement brightness_set_blocking op. It removes from LED class drivers responsibility for using work queues on their own. In order to achieve this set_brightness_delayed callback is being modified to directly call one of available ops for brightness setting. led_set_brightness_async() function didn't set brightness in an asynchronous way in all cases. It was mistakenly assuming that all LED subsystem drivers used work queue in their brightness_set op, whereas only half of them did that. Since it has no users now, it is being removed. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
2016-01-04leds: Rename brightness_set_sync op to brightness_set_blockingJacek Anaszewski1-2/+2
The initial purpose of brightness_set_sync op, introduced along with the LED flash class extension, was to add a means for setting torch LED brightness as soon as possible, which couldn't have been guaranteed by brightness_set op. This patch renames the op to brightness_set_blocking, which describes its purpose in a more generic way. It is beneficial in view of the prospective changes in the LED core, aiming at removing the need for using work queues in LED class drivers that can sleep or use delays while setting brightness. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
2016-01-04leds: core: Add two new LED_BLINK_ flagsJacek Anaszewski1-4/+6
This patch adds LED_BLINK_BRIGHTNESS_CHANGE flag to indicate that blink brightness has changed, and LED_BLINK_DISABLE flag to indicate that blinking deactivation has been requested. In order to use the flags led_timer_function and set_brightness_delayed callbacks as well as led_set_brightness() function are being modified. The main goal of these modifications is to prepare set_brightness_work for extension of the scope of its responsibilities. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
2015-10-26arcnet: com20020-pci: add led trigger supportMichael Grzeschik1-0/+7
The EAE PLX-PCI card has special leds on the the main io pci resource bar. This patch adds support to trigger the conflict and data leds with the packages. Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
2015-05-04leds: unify the location of led-trigger APIJacek Anaszewski1-0/+25
Part of led-trigger API was in the private drivers/leds/leds.h header. Move it to the include/linux/leds.h header to unify the API location and announce it as public. It has been already exported from led-triggers.c with EXPORT_SYMBOL_GPL macro. The no-op definitions are changed from macros to inline to match the style of the surrounding code. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2015-03-09leds: flash: Remove synchronized flash strobe featureJacek Anaszewski1-1/+0
Synchronized flash strobe feature has been considered not fitting for LED subsystem sysfs interface and thus is being removed. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2015-03-09leds: Introduce devres helper for led_classdev_registerBjorn Andersson1-0/+4
(cooloney@gmail.com: add _unregister function into the document) Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2015-01-26leds: Add LED Flash class extension to the LED subsystemJacek Anaszewski1-0/+3
Some LED devices support two operation modes - torch and flash. This patch provides support for flash LED devices in the LED subsystem by introducing new sysfs attributes and kernel internal interface. The attributes being introduced are: flash_brightness, flash_strobe, flash_timeout, max_flash_timeout, max_flash_brightness, flash_fault, flash_sync_strobe and available_sync_leds. All the flash related features are placed in a separate module. The modifications aim to be compatible with V4L2 framework requirements related to the flash devices management. The design assumes that V4L2 sub-device can take of the LED class device control and communicate with it through the kernel internal interface. When V4L2 Flash sub-device file is opened, the LED class device sysfs interface is made unavailable. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-12-15Merge branch 'for-next' of ↵Linus Torvalds1-0/+40
git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds Pull LED subsystem update from Bryan Wu: "We got some cleanup and driver for LP8860 as well as some patches for LED Flash Class" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds: leds: lp8860: Fix module dependency leds: lp8860: Introduce TI lp8860 4 channel LED driver leds: Add support for setting brightness in a synchronous way leds: implement sysfs interface locking mechanism leds: syscon: handle multiple syscon instances leds: delete copy/paste mistake leds: regulator: Convert to devm_regulator_get_exclusive
2014-11-14leds: Add support for setting brightness in a synchronous wayJacek Anaszewski1-0/+8
There are use cases when setting a LED brightness has to have immediate effect (e.g. setting a torch LED brightness). This patch extends LED subsystem to support such operations. The LED subsystem internal API __led_set_brightness is changed to led_set_brightness_async and new led_set_brightness_sync API is added. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-11-14leds: implement sysfs interface locking mechanismJacek Anaszewski1-0/+32
Add a mechanism for locking LED subsystem sysfs interface. This patch prepares ground for addition of LED Flash Class extension, whose API will be integrated with V4L2 Flash API. Such a fusion enforces introducing a locking scheme, which will secure consistent access to the LED Flash Class device. The mechanism being introduced allows for disabling LED subsystem sysfs interface by calling led_sysfs_disable function and enabling it by calling led_sysfs_enable. The functions alter the LED_SYSFS_DISABLE flag state and must be called under mutex lock. The state of the lock is checked with use of led_sysfs_is_disabled function. Such a design allows for providing immediate feedback to the user space on whether the LED Flash Class device is available or is under V4L2 Flash sub-device control. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-11-04leds: leds-gpio: Convert gpio_blink_set() to use GPIO descriptorsMika Westerberg1-1/+1
Commit 21f2aae91e902aad ("leds: leds-gpio: Add support for GPIO descriptors") already converted most of the driver to use GPIO descriptors. What is still missing is the platform specific hook gpio_blink_set() and board files which pass legacy GPIO numbers to this driver in platform data. In this patch we handle the former and convert gpio_blink_set() to take GPIO descriptor instead. In order to do this we convert the existing four users to accept GPIO descriptor and translate it to legacy GPIO number in the platform code. This effectively "pushes" legacy GPIO number usage from the driver to platforms. Also add comment to the remaining block describing that it is legacy code path and we are getting rid of it eventually. Suggested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-04leds: leds-gpio: Add support for GPIO descriptorsMika Westerberg1-0/+1
GPIO descriptors are the preferred way over legacy GPIO numbers nowadays. Convert the driver to use GPIO descriptors internally but still allow passing legacy GPIO numbers from platform data to support existing platforms. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Bryan Wu <cooloney@gmail.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-12leds: Improve and export led_update_brightnessJacek Anaszewski1-0/+10
led_update_brightness helper function used to be exploited only locally in the led-class.c module, where its result was being passed to the brightness_show sysfs callback. With the introduction of v4l2-flash subdevice the same functionality becomes required for reading current brightness from a LED device. This patch adds checking of return value of the brightness_get callback and moves the led_update_brightness() function to the LED subsystem public API. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-09-11leds: make brightness type consistent across whole subsystemJacek Anaszewski1-2/+2
Documentations states that brightness units type is enum led_brightness and this is the type used by the led API functions. Adjust the type of brightness variables in the struct led_classdev accordingly. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-09-11leds: Reorder include directivesJacek Anaszewski1-1/+1
Reorder include directives so that they are arranged in alphabetical order. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-09-02Revert "leds: convert blink timer to workqueue"Jiri Kosina1-1/+2
This reverts commit 8b37e1bef5a6b60e949e28a4db3006e4b00bd758. It's broken as it changes led_blink_set() in a way that it can now sleep (while synchronously waiting for workqueue to be cancelled). That's a problem, because it's possible that this function gets called from atomic context (tpt_trig_timer() takes a readlock and thus disables preemption). This has been brought up 3 weeks ago already [1] but no proper fix has materialized, and I keep seeing the problem since 3.17-rc1. [1] https://lkml.org/lkml/2014/8/16/128 BUG: sleeping function called from invalid context at kernel/workqueue.c:2650 in_atomic(): 1, irqs_disabled(): 0, pid: 2335, name: wpa_supplicant 5 locks held by wpa_supplicant/2335: #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff814c7c92>] rtnl_lock+0x12/0x20 #1: (&wdev->mtx){+.+.+.}, at: [<ffffffffc06e649c>] cfg80211_mgd_wext_siwessid+0x5c/0x180 [cfg80211] #2: (&local->mtx){+.+.+.}, at: [<ffffffffc0817dea>] ieee80211_prep_connection+0x17a/0x9a0 [mac80211] #3: (&local->chanctx_mtx){+.+.+.}, at: [<ffffffffc08081ed>] ieee80211_vif_use_channel+0x5d/0x2a0 [mac80211] #4: (&trig->leddev_list_lock){.+.+..}, at: [<ffffffffc081e68c>] tpt_trig_timer+0xec/0x170 [mac80211] CPU: 0 PID: 2335 Comm: wpa_supplicant Not tainted 3.17.0-rc3 #1 Hardware name: LENOVO 7470BN2/7470BN2, BIOS 6DET38WW (2.02 ) 12/19/2008 ffff8800360b5a50 ffff8800751f76d8 ffffffff8159e97f ffff8800360b5a30 ffff8800751f76e8 ffffffff810739a5 ffff8800751f77b0 ffffffff8106862f ffffffff810685d0 0aa2209200000000 ffff880000000004 ffff8800361c59d0 Call Trace: [<ffffffff8159e97f>] dump_stack+0x4d/0x66 [<ffffffff810739a5>] __might_sleep+0xe5/0x120 [<ffffffff8106862f>] flush_work+0x5f/0x270 [<ffffffff810685d0>] ? mod_delayed_work_on+0x80/0x80 [<ffffffff810945ca>] ? mark_held_locks+0x6a/0x90 [<ffffffff81068a5f>] ? __cancel_work_timer+0x6f/0x100 [<ffffffff810946ed>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [<ffffffff81068a6b>] __cancel_work_timer+0x7b/0x100 [<ffffffff81068b0e>] cancel_delayed_work_sync+0xe/0x10 [<ffffffff8147cf3b>] led_blink_set+0x1b/0x40 [<ffffffffc081e6b0>] tpt_trig_timer+0x110/0x170 [mac80211] [<ffffffffc081ecdd>] ieee80211_mod_tpt_led_trig+0x9d/0x160 [mac80211] [<ffffffffc07e4278>] __ieee80211_recalc_idle+0x98/0x140 [mac80211] [<ffffffffc07e59ce>] ieee80211_idle_off+0xe/0x10 [mac80211] [<ffffffffc0804e5b>] ieee80211_add_chanctx+0x3b/0x220 [mac80211] [<ffffffffc08062e4>] ieee80211_new_chanctx+0x44/0xf0 [mac80211] [<ffffffffc080838a>] ieee80211_vif_use_channel+0x1fa/0x2a0 [mac80211] [<ffffffffc0817df8>] ieee80211_prep_connection+0x188/0x9a0 [mac80211] [<ffffffffc081c246>] ieee80211_mgd_auth+0x256/0x2e0 [mac80211] [<ffffffffc07eab33>] ieee80211_auth+0x13/0x20 [mac80211] [<ffffffffc06cb006>] cfg80211_mlme_auth+0x106/0x270 [cfg80211] [<ffffffffc06ce085>] cfg80211_conn_do_work+0x155/0x3b0 [cfg80211] [<ffffffffc06cf670>] cfg80211_connect+0x3f0/0x540 [cfg80211] [<ffffffffc06e6148>] cfg80211_mgd_wext_connect+0x158/0x1f0 [cfg80211] [<ffffffffc06e651e>] cfg80211_mgd_wext_siwessid+0xde/0x180 [cfg80211] [<ffffffffc06e36c0>] ? cfg80211_wext_giwessid+0x50/0x50 [cfg80211] [<ffffffffc06e36dd>] cfg80211_wext_siwessid+0x1d/0x40 [cfg80211] [<ffffffff81584d0c>] ioctl_standard_iw_point+0x14c/0x3e0 [<ffffffff810946ed>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [<ffffffff8158502a>] ioctl_standard_call+0x8a/0xd0 [<ffffffff81584fa0>] ? ioctl_standard_iw_point+0x3e0/0x3e0 [<ffffffff81584b76>] wireless_process_ioctl.constprop.10+0xb6/0x100 [<ffffffff8158521d>] wext_handle_ioctl+0x5d/0xb0 [<ffffffff814cfb29>] dev_ioctl+0x329/0x620 [<ffffffff810946ed>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [<ffffffff8149c7f2>] sock_ioctl+0x142/0x2e0 [<ffffffff811b0140>] do_vfs_ioctl+0x300/0x520 [<ffffffff815a67fb>] ? sysret_check+0x1b/0x56 [<ffffffff810946ed>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [<ffffffff811b03e1>] SyS_ioctl+0x81/0xa0 [<ffffffff815a67d6>] system_call_fastpath+0x1a/0x1f wlan0: send auth to 00:0b:6b:3c:8c:e4 (try 1/3) wlan0: authenticated wlan0: associate with 00:0b:6b:3c:8c:e4 (try 1/3) wlan0: RX AssocResp from 00:0b:6b:3c:8c:e4 (capab=0x431 status=0 aid=2) wlan0: associated IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready cfg80211: Calling CRDA for country: NA wlan0: Limiting TX power to 27 (27 - 0) dBm as advertised by 00:0b:6b:3c:8c:e4 ================================= [ INFO: inconsistent lock state ] 3.17.0-rc3 #1 Not tainted --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/0/0 [HC0[0]:SC1[1]:HE1:SE0] takes: ((&(&led_cdev->blink_work)->work)){+.?...}, at: [<ffffffff810685d0>] flush_work+0x0/0x270 {SOFTIRQ-ON-W} state was registered at: [<ffffffff81094dbe>] __lock_acquire+0x30e/0x1a30 [<ffffffff81096c81>] lock_acquire+0x91/0x110 [<ffffffff81068608>] flush_work+0x38/0x270 [<ffffffff81068a6b>] __cancel_work_timer+0x7b/0x100 [<ffffffff81068b0e>] cancel_delayed_work_sync+0xe/0x10 [<ffffffff8147cf3b>] led_blink_set+0x1b/0x40 [<ffffffffc081e6b0>] tpt_trig_timer+0x110/0x170 [mac80211] [<ffffffffc081ecdd>] ieee80211_mod_tpt_led_trig+0x9d/0x160 [mac80211] [<ffffffffc07e4278>] __ieee80211_recalc_idle+0x98/0x140 [mac80211] [<ffffffffc07e59ce>] ieee80211_idle_off+0xe/0x10 [mac80211] [<ffffffffc0804e5b>] ieee80211_add_chanctx+0x3b/0x220 [mac80211] [<ffffffffc08062e4>] ieee80211_new_chanctx+0x44/0xf0 [mac80211] [<ffffffffc080838a>] ieee80211_vif_use_channel+0x1fa/0x2a0 [mac80211] [<ffffffffc0817df8>] ieee80211_prep_connection+0x188/0x9a0 [mac80211] [<ffffffffc081c246>] ieee80211_mgd_auth+0x256/0x2e0 [mac80211] [<ffffffffc07eab33>] ieee80211_auth+0x13/0x20 [mac80211] [<ffffffffc06cb006>] cfg80211_mlme_auth+0x106/0x270 [cfg80211] [<ffffffffc06ce085>] cfg80211_conn_do_work+0x155/0x3b0 [cfg80211] [<ffffffffc06cf670>] cfg80211_connect+0x3f0/0x540 [cfg80211] [<ffffffffc06e6148>] cfg80211_mgd_wext_connect+0x158/0x1f0 [cfg80211] [<ffffffffc06e651e>] cfg80211_mgd_wext_siwessid+0xde/0x180 [cfg80211] [<ffffffffc06e36dd>] cfg80211_wext_siwessid+0x1d/0x40 [cfg80211] [<ffffffff81584d0c>] ioctl_standard_iw_point+0x14c/0x3e0 [<ffffffff8158502a>] ioctl_standard_call+0x8a/0xd0 [<ffffffff81584b76>] wireless_process_ioctl.constprop.10+0xb6/0x100 [<ffffffff8158521d>] wext_handle_ioctl+0x5d/0xb0 [<ffffffff814cfb29>] dev_ioctl+0x329/0x620 [<ffffffff8149c7f2>] sock_ioctl+0x142/0x2e0 [<ffffffff811b0140>] do_vfs_ioctl+0x300/0x520 [<ffffffff811b03e1>] SyS_ioctl+0x81/0xa0 [<ffffffff815a67d6>] system_call_fastpath+0x1a/0x1f irq event stamp: 493416 hardirqs last enabled at (493416): [<ffffffff81068a5f>] __cancel_work_timer+0x6f/0x100 hardirqs last disabled at (493415): [<ffffffff81067e9f>] try_to_grab_pending+0x1f/0x160 softirqs last enabled at (493408): [<ffffffff81053ced>] _local_bh_enable+0x1d/0x50 softirqs last disabled at (493409): [<ffffffff81054c75>] irq_exit+0xa5/0xb0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((&(&led_cdev->blink_work)->work)); <Interrupt> lock((&(&led_cdev->blink_work)->work)); *** DEADLOCK *** 2 locks held by swapper/0/0: #0: (((&tpt_trig->timer))){+.-...}, at: [<ffffffff810b4c50>] call_timer_fn+0x0/0x180 #1: (&trig->leddev_list_lock){.+.?..}, at: [<ffffffffc081e68c>] tpt_trig_timer+0xec/0x170 [mac80211] stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.17.0-rc3 #1 Hardware name: LENOVO 7470BN2/7470BN2, BIOS 6DET38WW (2.02 ) 12/19/2008 ffffffff8246eb30 ffff88007c203b00 ffffffff8159e97f ffffffff81a194c0 ffff88007c203b50 ffffffff81599c29 0000000000000001 ffffffff00000001 ffff880000000000 0000000000000006 ffffffff81a194c0 ffffffff81093ad0 Call Trace: <IRQ> [<ffffffff8159e97f>] dump_stack+0x4d/0x66 [<ffffffff81599c29>] print_usage_bug+0x1f4/0x205 [<ffffffff81093ad0>] ? check_usage_backwards+0x140/0x140 [<ffffffff810944d3>] mark_lock+0x223/0x2b0 [<ffffffff81094d60>] __lock_acquire+0x2b0/0x1a30 [<ffffffff81096c81>] lock_acquire+0x91/0x110 [<ffffffff810685d0>] ? mod_delayed_work_on+0x80/0x80 [<ffffffffc081e5a0>] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [<ffffffff81068608>] flush_work+0x38/0x270 [<ffffffff810685d0>] ? mod_delayed_work_on+0x80/0x80 [<ffffffff810945ca>] ? mark_held_locks+0x6a/0x90 [<ffffffff81068a5f>] ? __cancel_work_timer+0x6f/0x100 [<ffffffffc081e5a0>] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [<ffffffff8109469d>] ? trace_hardirqs_on_caller+0xad/0x1c0 [<ffffffffc081e5a0>] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [<ffffffff81068a6b>] __cancel_work_timer+0x7b/0x100 [<ffffffff81068b0e>] cancel_delayed_work_sync+0xe/0x10 [<ffffffff8147cf3b>] led_blink_set+0x1b/0x40 [<ffffffffc081e6b0>] tpt_trig_timer+0x110/0x170 [mac80211] [<ffffffff810b4cc5>] call_timer_fn+0x75/0x180 [<ffffffff810b4c50>] ? process_timeout+0x10/0x10 [<ffffffffc081e5a0>] ? __ieee80211_get_rx_led_name+0x10/0x10 [mac80211] [<ffffffff810b50ac>] run_timer_softirq+0x1fc/0x2f0 [<ffffffff81054805>] __do_softirq+0x115/0x2e0 [<ffffffff81054c75>] irq_exit+0xa5/0xb0 [<ffffffff810049b3>] do_IRQ+0x53/0xf0 [<ffffffff815a74af>] common_interrupt+0x6f/0x6f <EOI> [<ffffffff8147b56e>] ? cpuidle_enter_state+0x6e/0x180 [<ffffffff8147b732>] cpuidle_enter+0x12/0x20 [<ffffffff8108bba0>] cpu_startup_entry+0x330/0x360 [<ffffffff8158fb51>] rest_init+0xc1/0xd0 [<ffffffff8158fa90>] ? csum_partial_copy_generic+0x170/0x170 [<ffffffff81af3ff2>] start_kernel+0x44f/0x45a [<ffffffff81af399c>] ? set_init_arg+0x53/0x53 [<ffffffff81af35ad>] x86_64_start_reservations+0x2a/0x2c [<ffffffff81af36a0>] x86_64_start_kernel+0xf1/0xf4 Cc: Vincent Donnefort <vdonnefort@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-07-03leds: convert blink timer to workqueueVincent Donnefort1-2/+1
This patch converts the blink timer from led-core to workqueue which is more suitable for this kind of non-priority operations. Moreover, timer may lead to errors when a LED setting function use a scheduling function such as pinctrl which is using mutex. Signed-off-by: Vincent Donnefort <vdonnefort@gmail.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2014-06-25leds: add led-class attribute-group supportJohan Hovold1-0/+2
Allow led-class devices to be created with optional attribute groups. This is needed in order to allow led drivers to create custom device attributes in a race-free manner. Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2013-04-01leds: add camera LED triggersKim, Milo1-0/+8
Some LED devices support flash/torch functionality through the LED subsystem. This patch enables direct LED trigger controls by the driver. Flash on/off and torch on/off can be done simply by other driver space. Two trigger APIs are added, ledtrig_flash_ctrl() and ledtrig_torch_ctrl(). Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2013-04-01leds: trigger: use inline functions instead of macrosKim, Milo1-11/+14
Macros are used in case that an inline function doesn't work. Otherwise, use an empty inline function. (a) Case of !CONFIG_LEDS_TRIGGERS Following macros are replaced with inline functions. led_trigger_register_simple() led_trigger_unregister_simple() led_trigger_event() To make inline types, the structure, 'led_trigger' should be defined. This structure has no member at all. (b) Case of !CONFIG_LEDS_TRIGGER_IDE_DISK ledtrig_ide_activity() macro is replaced with an inline function as well. (c) DEFINE_LED_TRIGGER() and DEFINE_LED_TRIGGER_GLOBAL() Struct 'led_trigger' is defined both cases, with CONFIG_LEDS_TRIGGERS and without CONFIG_LEDS_TRIGGERS. Those macros are moved out of CONFIG_LED_TRIGGERS because of no-dependency on CONFIG_LEDS_TRIGGERS. (d) Fix build errors in mmc-core driver After replacing macros with inline functions, following build errors occur. (condition: CONFIG_LEDS_TRIGGERS is not set) drivers/mmc/core/core.c: In function 'mmc_request_done': drivers/mmc/core/core.c:164:25: error: 'struct mmc_host' has no member named 'led' drivers/mmc/core/core.c: In function 'mmc_start_request': drivers/mmc/core/core.c:254:24: error: 'struct mmc_host' has no member named 'led' make[3]: *** [drivers/mmc/core/core.o] Error 1 The reason of these errors is non-existent member variable, 'led'. It is only valid when CONFIG_LEDS_TRIGGERS is set. But now, it can be used without this dependency. To fix build errors, member 'led' is always used without its config option in 'include/linux/mmc/host.h'. Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2012-11-26led: Add dependency on CONFIG_LEDS_TRIGGERS to led_trigger_rename_static()Jingoo Han1-18/+17
This patch fixes build warnings when CONFIG_LEDS_TRIGGERS is disabled as below: include/linux/leds.h:158:18: warning: 'struct led_trigger' declared inside parameter list [enabled by default] include/linux/leds.h:158:18: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default] Signed-off-by: Jingoo Han <jg1.han@samsung.com> Acked-by: Fabio Baltieri <fabio.baltieri@gmail.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2012-11-26leds: add led_trigger_rename functionFabio Baltieri1-0/+18
Implements a "led_trigger_rename" function to rename a trigger with proper locking. This assumes that led name was originally allocated in non-constant storage. Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com> Cc: Kurt Van Dijck <kurt.van.dijck@eia.be> Signed-off-by: Bryan Wu <cooloney@gmail.com>
2012-10-10Merge branch 'for-next' of ↵Linus Torvalds1-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds Pull LED subsystem update from Bryan Wu. * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds: (24 commits) leds: add output driver configuration for pca9633 led driver leds: lm3642: Use regmap_update_bits() in lm3642_chip_init() leds: Add new LED driver for lm3642 chips leds-lp5523: Fix riskiness of the page fault leds-lp5523: turn off the LED engines on unloading the driver leds-lm3530: Fix smatch warnings leds-lm3530: Use devm_regulator_get function leds: leds-gpio: adopt pinctrl support leds: Add new LED driver for lm355x chips leds-lp5523: use the i2c device id rather than fixed name leds-lp5523: add new device id for LP55231 leds-lp5523: support new LP55231 device leds: triggers: send uevent when changing triggers leds-lp5523: minor code style fixes leds-lp5523: change the return type of lp5523_set_mode() leds-lp5523: set the brightness to 0 forcely on removing the driver leds-lp5523: add channel name in the platform data leds: leds-gpio: Use of_get_child_count() helper leds: leds-gpio: Use platform_{get,set}_drvdata leds: leds-gpio: use of_match_ptr() ...
2012-09-11leds: delay led_set_brightness if stopping soft-blinkFabio Baltieri1-0/+4
Delay execution of led_set_brightness() if need to stop soft-blink timer. This allows led_set_brightness to be called in hard-irq context even if soft-blink was activated on that LED. Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com> Cc: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-08-13Merge branch 'for-arm-soc' of ↵Arnd Bergmann1-0/+16
git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds into next/drivers From Bryan Wu <bryan.wu@canonical.com>: Based on Linus Walleij's ARM LED consolidation work, this patchset introduce a new generic led trigger for CPU not only for ARM but also for others. For enabling CPU idle event, CPU arch code should call ledtrig_cpu() stub to trigger idle start or idle end event. These patches convert old style LED driver in arch/arm to gpio_led or new led driver interface. Against 3.5 release and build successfully for all the machines. Test ledtrig-cpu driver on OMAP4 Panda board. v9 --> v10 * fix compiling issue on versatile_defconfig reported by Russell King * rebase to 3.5 kernel and move patches to new git tree v8 --> v9: * use mutex to replace rw_sema pointed out by Tim Gardner * add a new struct led_trigger_cpu * add lock_is_inited to record mutex lock initialization v6 --> v7: * add a patch to unify the led-trigger name * fix some typo pointed * use BUG_ON to detect CPU numbers during building stage v5 --> v6: * replace __get_cpu_var() to per_cpu() * remove smp_processor_id() which is wrong with for_each_possible_cpu() * test on real OMAP4 Panda board * add comments about CPU hotplug in the CPU LED trigger driver v4 --> v5: * rebase all the patches on top of latest linux-next * replace on_each_cpu() with for_each_possible_cpu() * add some description of ledtrig_cpu() API * remove old leds code from driver nwflash.c, which should use a new led trigger then * this trigger driver can be built as module now v3 --> v4: * fix a typo pointed by Jochen Friedrich * fix some building errors * add Reviewed-by and Tested-by into patch log v2 --> v3: * almost rewrote the whole ledtrig-cpu driver, which is more simple * every CPU will have a per-CPU trigger * cpu trigger can be assigned to any leds * fix a lockdep issue in led-trigger common code * other fix according to review v1 --> v2: * remove select operations in Kconfig of every machines * add back supporting of led in core module of mach-integrator * solidate name scheme in ledtrig-cpu.c * add comments of CPU_LED_* cpu led events * fold patches of RealView and Versatile together * add machine_is_ check during assabet led driver init * add some Acked-by in patch logs * remove code for simpad machine in machine-sa11000, since Jochen Friedrich introduced gpiolib and gpio-led driver for simpad * on Assabet and Netwinder machine, LED operations is reversed like: setting bit means turn off leds clearing bit means turn on leds * add a new function to read CM_CTRL register for led driver * 'for-arm-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds: ARM: use new LEDS CPU trigger stub to replace old one ARM: mach-sa1100: retire custom LED code ARM: mach-omap1: retire custom LED code ARM: mach-pnx4008: remove including old leds event API header file ARM: plat-samsung: remove including old leds event API header file ARM: mach-pxa: retire custom LED code char: nwflash: remove old led event code ARM: mach-footbridge: retire custom LED code ARM: mach-ebsa110: retire custom LED code ARM: mach-clps711x: retire custom LED code of P720T machine ARM: mach-integrator: retire custom LED code ARM: mach-integrator: move CM_CTRL to header file for accessing by other functions ARM: mach-orion5x: convert custom LED code to gpio_led and LED CPU trigger ARM: mach-shark: retire custom LED code ARM: mach-ks8695: remove leds driver, since nobody use it ARM: mach-realview and mach-versatile: retire custom LED code ARM: at91: convert old leds drivers to gpio_led and led_trigger drivers led-triggers: create a trigger for CPU activity Conflicts: arch/arm/mach-clps711x/p720t.c arch/arm/mach-sa1100/leds-cerf.c arch/arm/mach-sa1100/leds-lart.c Let's hope this is the last time we pull this and it doesn't cause more trouble. I have verified that version 10 causes no build warnings or errors any more, and the patches still look good. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-07-31led-triggers: create a trigger for CPU activityBryan Wu1-0/+16
Attempting to consolidate the ARM LED code, this removes the custom RealView LED trigger code to turn LEDs on and off in response to CPU activity and replace it with a standard trigger. (bryan.wu@canonical.com: It introduces several syscore stubs into this trigger. It also provides ledtrig_cpu trigger event stub in <linux/leds.h>. Although it was inspired by ARM work, it can be used in other arch.) Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Bryan Wu <bryan.wu@canonical.com> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Tested-by: Jochen Friedrich <jochen@scram.de>
2012-07-24leds: Rename led_brightness_set() to led_set_brightness()Shuah Khan1-2/+2
Rename leds external interface led_brightness_set() to led_set_brightness(). This is the second phase of the change to reduce confusion between the leds internal and external interfaces that set brightness. With this change, now the external interface is led_set_brightness(). The first phase renamed the internal interface led_set_brightness() to __led_set_brightness(). There are no changes to the interface implementations. Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-07-24leds: add oneshot blink functionsFabio Baltieri1-0/+25
Add two new functions, led_blink_set_oneshot and led_trigger_blink_oneshot, to be used by triggers for one-shot blink of led devices. This is implemented extending the existing software-blink code, and uses the same timer and handler function. The behavior of the code is to do a blink-on, blink-off sequence when the function is called, ignoring other calls until the sequence is completed so that the leds keep blinking at constant rate if the functions are called repeatedly. This is meant to be used by drivers which needs to trigger on sporadic event, but doesn't have clear busy/idle trigger points. After the blink sequence the led remains off. This behavior can be inverted setting the "invert" argument, which blink the led off, than on and leave the led on after the sequence. (bryan.wu@canonical.com: rebase to commit 'leds: don't disable blinking when writing the same value to delay_on or delay_off') Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com> Acked-by: Shuah Khan <shuahkhan@gmail.com> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-05-29leds: add new field to led_classdev struct to save activation stateShuah Khan1-0/+2
Add a new field to led_classdev to save activattion state after activate routine is successful. This saved state is used in deactivate routine to do cleanup such as removing device files, and free memory allocated during activation. Currently trigger_data not being null is used for this purpose. Existing triggers will need changes to use this new field. Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Bryan Wu <bryan.wu@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25leds: provide helper to register "leds-gpio" devicesUwe Kleine-König1-0/+2
This function makes a deep copy of the platform data to allow it to live in init memory. For a kernel that supports several machines and so includes the definition for several leds-gpio devices this saves quite some memory because all but one definition can be free'd after boot. As the function is used by arch code it must be builtin and so cannot go into leds-gpio.c. [akpm@linux-foundation.org: s/CONFIG_LED_REGISTER_GPIO/CONFIG_LEDS_REGISTER_GPIO/] Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Russell King <rmk@arm.linux.org.uk> Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org> Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Tested-by: H Hartley Sweeten <hartleys@visionengravers.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-25Merge git://git.infradead.org/battery-2.6Linus Torvalds1-0/+3
* git://git.infradead.org/battery-2.6: (30 commits) bq20z75: Fix time and temp units bq20z75: Fix issues with present and suspend z2_battery: Fix count of properties s3c_adc_battery: Fix method names when PM not set z2_battery: Add MODULE_DEVICE_TABLE ds2782_battery: Add MODULE_DEVICE_TABLE bq20z75: Add MODULE_DEVICE_TABLE power_supply: Update power_supply_is_watt_property bq20z75: Add i2c retry mechanism bq20z75: Add optional battery detect gpio twl4030_charger: Make the driver atomic notifier safe bq27x00: Use single i2c_transfer call for property read bq27x00: Cleanup bq27x00_i2c_read bq27x00: Minor cleanups bq27x00: Give more specific reports on battery status bq27x00: Add MODULE_DEVICE_TABLE bq27x00: Add new properties bq27x00: Poll battery state bq27x00: Cache battery registers bq27x00: Add bq27000 support ...
2011-03-22leds: make *struct gpio_led_platform_data.leds constUwe Kleine-König1-2/+2
And fix a typo. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-31leds: Add ability to blink via simple triggerVasily Khoruzhick1-0/+3
As blink API is now available, it's possible to add ability to blink via simple trigger. Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
2010-11-12led-class: always implement blinkingJohannes Berg1-4/+43
Currently, blinking LEDs can be awkward because it is not guaranteed that all LEDs implement blinking. The trigger that wants it to blink then needs to implement its own timer solution. Rather than require that, add led_blink_set() API that triggers can use. This function will attempt to use hw blinking, but if that fails implements a timer for it. To stop blinking again, brightness_set() also needs to be wrapped into API that will stop the software blink. As a result of this, the timer trigger becomes a very trivial one, and hopefully we can finally see triggers using blinking as well because it's always easy to use. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-by: Richard Purdie <rpurdie@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26leds: leds-gpio: Change blink_set callback to be able to turn off blinkingBenjamin Herrenschmidt1-4/+8
The leds-gpio blink_set() callback follows the same prototype as the main leds subsystem blink_set() one. The problem is that to stop blink, normally, a leds driver does it in the brightness_set() callback when asked to set a new fixed value. However, with leds-gpio, the platform has no hook to do so, as this later callback results in a standard GPIO manipulation. This changes the leds-gpio specific callback to take a new argument that indicates whether the LED should be blinking or not and in what state it should be set if not. We also update the dns323 platform which seems to be the only user of this so far. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-06-23leds: Futher document blink_setRichard Purdie1-1/+2
Futher document blink_set function pointer Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-06-23leds: Add options to have GPIO LEDs start on or keep their stateTrent Piepho1-2/+7
There already is a "default-on" trigger but there are problems with it. For one, it's a inefficient way to do it and requires led trigger support to be compiled in. But the real reason is that is produces a glitch on the LED. The GPIO is allocate with the LED *off*, then *later* when the trigger runs it is turned back on. If the LED was already on via the GPIO's reset default or action of the firmware, this produces a glitch where the LED goes from on to off to on. While normally this is fast enough that it wouldn't be noticeable to a human observer, there are still serious problems. One is that there may be something else on the GPIO line, like a hardware alarm or watchdog, that is fast enough to notice the glitch. Another is that the kernel may panic before the LED is turned back on, thus hanging with the LED in the wrong state. This is not just speculation, but actually happened to me with an embedded system that has an LED which should turn off when the kernel finishes booting, which was left in the incorrect state due to a bug in the OF LED binding code. We also let GPIO LEDs get their initial value from whatever the current state of the GPIO line is. On some systems the LEDs are put into some state by the firmware or hardware before Linux boots, and it is desired to have them keep this state which is otherwise unknown to Linux. This requires that the underlying GPIO driver support reading the value of output GPIOs. Some drivers support this and some do not. The platform device binding gains a field in the platform data "default_state" that controls this. There are three constants defined to select from on, off, or keeping the current state. The OpenFirmware binding uses a property named "default-state" that can be set to "on", "off", or "keep". The default if the property isn't present is off. Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Sean MacLennan <smaclennan@pikatech.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-06-23leds: Further document parameters for blink_set()Mark Brown1-1/+3
The documentation for the parameters of blink_set() was a bit hard to find so put some where I'd expected to find it. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-04-06leds: Add suspend/resume state flags to leds-gpioRichard Purdie1-1/+2
Add an option to preserve LED state when suspending/resuming to the LED gpio driver. Based on a suggestion from Robert Jarzmik. Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-04-06leds: allow led-drivers to use a variable range of brightness valuesGuennadi Liakhovetski1-0/+1
This patch allows drivers to override the default maximum brightness value of 255. We take care to preserve backwards-compatibility as much as possible, so that user-space ABI doesn't change for existing drivers. LED trigger code has also been updated to use the per-LED maximum. Signed-off-by: Guennadi Liakhovetski <lg@denx.de> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-01-08leds: Add suspend/resume to the core classRichard Purdie1-0/+3
Add suspend/resume to the core class and remove all the now unneeded code from various drivers. Originally the class code couldn't support suspend/resume but since class_device can there is no reason for each driver doing its own suspend/resume anymore.
2009-01-08leds: Make header variable naming consistentWolfram Sang1-1/+1
There is one place where the struct led_classdev as the function argument is named differently. Fix it. Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2008-10-20leds: Make default trigger fields constTrent Piepho1-2/+2
The default_trigger fields of struct gpio_led and thus struct led_classdev are pretty much always assigned from a string literal, which means the string can't be modified. Which is fine, since there is no reason to modify the string and in fact it never is. But they should be marked const to prevent such code from being added, to prevent warnings if -Wwrite-strings is used, when assigned from a constant string other than a string literal (which produces a warning under current kernel compiler flags), and for general good coding practices. Signed-off-by: Trent Piepho <tpiepho@freescale.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2008-07-23leds: Add support for Philips PCA955x I2C LED driversNate Case1-0/+14
This driver supports the PCA9550, PCA9551, PCA9552, and PCA9553 LED driver chips. Signed-off-by: Nate Case <ncase@xes-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2008-07-23leds: mark led_classdev.default_trigger as constAnton Vorontsov1-1/+1
LED classdev core doesn't modify memory pointed by the default_trigger, so mark it as const and we'll able to pass const char *s without getting compiler warnings. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2008-04-24leds: Document the context brightness_set needsRichard Purdie1-0/+1
Make sure there is no confusion about the contexts brightness_set can be called under by documenting it. Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2008-04-24leds: Add support to leds with readable statusHenrique de Moraes Holschuh1-0/+2
Some led hardware allows drivers to query the led state, and this patch adds a hook to let the led class take advantage of that information when available. Without this functionality, when access to the led hardware is not exclusive (i.e. firmware or hardware might change its state behind the kernel's back), reality goes out of sync with the led class' idea of what the led is doing, which is annoying at best. Behaviour for drivers that do not or cannot read the led status is unchanged. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Richard Purdie <rpurdie@rpsys.net>