Commit Graph

100 Commits

Author SHA1 Message Date
Jacek Anaszewski 3ef7de5304 leds: Improve and export led_update_brightness
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>
2014-09-12 14:01:54 -07:00
Jacek Anaszewski d8082827d8 leds: make brightness type consistent across whole subsystem
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>
2014-09-11 16:55:25 -07:00
Jacek Anaszewski 047133066e leds: Reorder include directives
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>
2014-09-11 16:55:25 -07:00
Jiri Kosina 9067359faf Revert "leds: convert blink timer to workqueue"
This reverts commit 8b37e1bef5.

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>
2014-09-02 10:02:13 -07:00
Vincent Donnefort 8b37e1bef5 leds: convert blink timer to workqueue
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>
2014-07-03 12:02:14 -07:00
Johan Hovold d0d480cce8 leds: add led-class attribute-group support
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>
2014-06-25 14:55:03 -07:00
Kim, Milo 48a1d032c9 leds: add camera LED triggers
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>
2013-04-01 11:04:50 -07:00
Kim, Milo 39f7e08af3 leds: trigger: use inline functions instead of macros
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>
2013-04-01 11:04:50 -07:00
Jingoo Han 057407c732 led: Add dependency on CONFIG_LEDS_TRIGGERS to led_trigger_rename_static()
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>
2012-11-26 14:28:51 -08:00
Fabio Baltieri a8df7b1ab7 leds: add led_trigger_rename function
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>
2012-11-26 14:28:50 -08:00
Linus Torvalds c7a6ced9d8 Merge branch 'for-next' of 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()
  ...
2012-10-10 20:14:07 +09:00
Fabio Baltieri d23a22a74f leds: delay led_set_brightness if stopping soft-blink
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>
2012-09-11 18:32:40 +08:00
Arnd Bergmann 19e4ab54e7 Merge branch 'for-arm-soc' of 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>
2012-08-13 16:45:48 +02:00
Bryan Wu 8f88731d05 led-triggers: create a trigger for CPU activity
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>
2012-07-31 21:23:31 +08:00
Shuah Khan 19cd67e2d5 leds: Rename led_brightness_set() to led_set_brightness()
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>
2012-07-24 07:52:34 +08:00
Fabio Baltieri 5bb629c504 leds: add oneshot blink functions
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>
2012-07-24 07:52:34 +08:00
Shuah Khan b00961824a leds: add new field to led_classdev struct to save activation state
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>
2012-05-29 16:22:31 -07:00
Uwe Kleine-König 4440673a95 leds: provide helper to register "leds-gpio" devices
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>
2011-05-25 08:39:51 -07:00
Linus Torvalds 56a9ccb7ba Merge git://git.infradead.org/battery-2.6
* 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
  ...
2011-03-25 21:00:29 -07:00
Uwe Kleine-König 9517f925f2 leds: make *struct gpio_led_platform_data.leds const
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>
2011-03-22 17:43:59 -07:00
Vasily Khoruzhick 0b9536c957 leds: Add ability to blink via simple trigger
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>
2011-01-31 16:30:24 +03:00
Johannes Berg 5ada28bf76 led-class: always implement blinking
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>
2010-11-12 07:55:32 -08:00
Benjamin Herrenschmidt 2146325df2 leds: leds-gpio: Change blink_set callback to be able to turn off blinking
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>
2010-05-26 13:07:55 +01:00
Richard Purdie a1dd8c6172 leds: Futher document blink_set
Futher document blink_set function pointer

Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-06-23 20:21:39 +01:00
Trent Piepho ed88bae691 leds: Add options to have GPIO LEDs start on or keep their state
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>
2009-06-23 20:21:39 +01:00
Mark Brown 92722b1bb1 leds: Further document parameters for blink_set()
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>
2009-06-23 20:20:35 +01:00
Richard Purdie defb512d25 leds: Add suspend/resume state flags to leds-gpio
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>
2009-04-06 16:06:26 +01:00
Guennadi Liakhovetski 1bd465e6b0 leds: allow led-drivers to use a variable range of brightness values
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>
2009-04-06 16:06:25 +01:00
Richard Purdie 859cb7f2a4 leds: Add suspend/resume to the core class
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.
2009-01-08 17:55:03 +00:00
Wolfram Sang e2387d6c20 leds: Make header variable naming consistent
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>
2009-01-08 12:38:57 +00:00
Trent Piepho 326bb8a5a1 leds: Make default trigger fields const
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>
2008-10-20 22:34:12 +01:00
Nate Case f46e9203d9 leds: Add support for Philips PCA955x I2C LED drivers
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>
2008-07-23 09:49:56 +01:00
Anton Vorontsov 781a54e766 leds: mark led_classdev.default_trigger as const
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>
2008-07-23 09:49:56 +01:00
Richard Purdie 2e214e0fa2 leds: Document the context brightness_set needs
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>
2008-04-24 23:49:30 +01:00
Henrique de Moraes Holschuh 29d76dfa29 leds: Add support to leds with readable status
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>
2008-04-24 23:37:42 +01:00
Herbert Valerio Riedel ca3259b360 leds: enable support for blink_set() platform hook in leds-gpio
Enhance leds-gpio to provide hardware-based led flashing by passing
through the blink_set() call to a optionally set platform-specific
function pointer.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2008-04-24 23:37:42 +01:00
Rafael J. Wysocki b844eba292 PM: Remove destroy_suspended_device()
After 2.6.24 there was a plan to make the PM core acquire all device
semaphores during a suspend/hibernation to protect itself from
concurrent operations involving device objects.  That proved to be
too heavy-handed and we found a better way to achieve the goal, but
before it happened, we had introduced the functions
device_pm_schedule_removal() and destroy_suspended_device() to allow
drivers to "safely" destroy a suspended device and we had adapted some
drivers to use them.  Now that these functions are no longer necessary,
it seems reasonable to remove them and modify their users to use the
normal device unregistration instead.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-19 19:10:28 -07:00
Márton Németh 4c79141d28 leds: Add support for hardware accelerated LED flashing
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 <nm127@freemail.hu>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2008-02-07 09:49:38 +00:00
Rafael J. Wysocki fa23f5cce8 leds: add possibility to remove leds classdevs during suspend/resume
Make it possible to unregister a led classdev object in a safe way during a
suspend/resume cycle.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:23 -08:00
Richard Purdie dc47206e55 leds: Fix led trigger locking bugs
Convert part of the led trigger core from rw spinlocks to rw
semaphores. We're calling functions which can sleep from invalid
contexts otherwise. Fixes bug #9264.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2007-12-07 09:06:53 +00:00
Yoichi Yuasa df96efd73b leds: Add missing include for leds.h
This patch has added #include <linux/spinlock.h> to include/linux/leds.h
for rwlock_t.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2007-09-11 22:24:45 +01:00
Linus Torvalds d7f5e3df35 Merge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds
* 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds:
  leds: Convert from struct class_device to struct device
  leds: leds-gpio for ngw100
  leds: Add warning printks in error paths
  leds: Fix trigger unregister_simple if register_simple fails
  leds: Use menuconfig objects II - LED
  leds: Teach leds-gpio to handle timer-unsafe GPIOs
  leds: Add generic GPIO LED driver
2007-07-22 11:22:01 -07:00
Robert P. J. Day 0a3021f4e2 Remove unnecessary includes of spinlock.h under include/linux
Remove the obviously unnecessary includes of <linux/spinlock.h> under the
include/linux/ directory, and fix the couple errors that are introduced as
a result of that.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:42 -07:00
Richard Purdie f8a7c6fe14 leds: Convert from struct class_device to struct device
Convert the LEDs class from struct class_device to struct device
since class_device is scheduled for removal.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-16 01:15:51 +01:00
Raphael Assenat 22e03f3b58 leds: Add generic GPIO LED driver
This patch adds support for GPIO connected leds via the new GPIO framework.

Information about leds (gpio, polarity, name, default trigger) is passed
to the driver via platform_data.

Signed-off-by: Raphael Assenat <raph@8d.com>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2007-07-16 01:15:50 +01:00
Johannes Berg af410fc13d [PATCH] make leds.h include relevant headers
Make it possible to include linux/leds.h without first including list.h and
spinlock.h.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:13 -07:00
Ben Dooks fb5035dbbe [PATCH] leds: re-layout include/linux/leds.h
Lay out the structure definitions in include/linux/leds.h to be aligned as
much as possible.  Also minor updates to the comments to make them more
concise.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:41 -07:00
Richard Purdie 2bfb646cdf [PATCH] LED: Add IDE disk activity LED trigger
Add an LED trigger for IDE disk activity to the ide-disk driver.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:18:57 -08:00
Richard Purdie c3bc9956ec [PATCH] LED: add LED trigger tupport
Add support for LED triggers to the LED subsystem.  "Triggers" are events
which change the state of an LED.  Two kinds of trigger are available, simple
ones which can be added to exising code with minimum disruption and complex
ones for implementing new or more complex functionality.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:18:56 -08:00
Richard Purdie c72a1d608d [PATCH] LED: add LED class
Add the foundations of a new LEDs subsystem.  This patch adds a class which
presents LED devices within sysfs and allows their brightness to be
controlled.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:18:56 -08:00