138 Commits
Author SHA1 Message Date
Andy ShevchenkoandLee Jones cb335325b1 leds: Unexport of_led_get()
There are no users outside the module.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250630092639.1574860-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Lee Jones <lee@kernel.org>
2025-07-02 17:18:01 +01:00
Thomas ZimmermannandLee Jones dc2139c0aa leds: backlight trigger: Replace fb events with a dedicated function call
Remove support for fb events from the led backlight trigger. Provide
the helper ledtrig_backlight_blank() instead. Call it from fbdev to
inform the trigger of changes to a display's blank state.

Fbdev maintains a list of all installed notifiers. Instead of the fbdev
notifiers, maintain an internal list of led backlight triggers.

v3:
- export ledtrig_backlight_blank()
v2:
- maintain global list of led backlight triggers (Lee)
- avoid IS_REACHABLE() in source file (Lee)
- notify on changes to blank state instead of display state
- use lock guards
- initialize led list and list mutex

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Simona Vetter <simona.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20250321095517.313713-11-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
2025-04-10 10:39:13 +01:00
Mukesh OjhaandLee Jones 4ca7cd9387 leds: class: Protect brightness_show() with led_cdev->led_access mutex
There is NULL pointer issue observed if from Process A where hid device
being added which results in adding a led_cdev addition and later a
another call to access of led_cdev attribute from Process B can result
in NULL pointer issue.

Use mutex led_cdev->led_access to protect access to led->cdev and its
attribute inside brightness_show() and max_brightness_show() and also
update the comment for mutex that it should be used to protect the led
class device fields.

	Process A 				Process B

 kthread+0x114
 worker_thread+0x244
 process_scheduled_works+0x248
 uhid_device_add_worker+0x24
 hid_add_device+0x120
 device_add+0x268
 bus_probe_device+0x94
 device_initial_probe+0x14
 __device_attach+0xfc
 bus_for_each_drv+0x10c
 __device_attach_driver+0x14c
 driver_probe_device+0x3c
 __driver_probe_device+0xa0
 really_probe+0x190
 hid_device_probe+0x130
 ps_probe+0x990
 ps_led_register+0x94
 devm_led_classdev_register_ext+0x58
 led_classdev_register_ext+0x1f8
 device_create_with_groups+0x48
 device_create_groups_vargs+0xc8
 device_add+0x244
 kobject_uevent+0x14
 kobject_uevent_env[jt]+0x224
 mutex_unlock[jt]+0xc4
 __mutex_unlock_slowpath+0xd4
 wake_up_q+0x70
 try_to_wake_up[jt]+0x48c
 preempt_schedule_common+0x28
 __schedule+0x628
 __switch_to+0x174
						el0t_64_sync+0x1a8/0x1ac
						el0t_64_sync_handler+0x68/0xbc
						el0_svc+0x38/0x68
						do_el0_svc+0x1c/0x28
						el0_svc_common+0x80/0xe0
						invoke_syscall+0x58/0x114
						__arm64_sys_read+0x1c/0x2c
						ksys_read+0x78/0xe8
						vfs_read+0x1e0/0x2c8
						kernfs_fop_read_iter+0x68/0x1b4
						seq_read_iter+0x158/0x4ec
						kernfs_seq_show+0x44/0x54
						sysfs_kf_seq_show+0xb4/0x130
						dev_attr_show+0x38/0x74
						brightness_show+0x20/0x4c
						dualshock4_led_get_brightness+0xc/0x74

[ 3313.874295][ T4013] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000060
[ 3313.874301][ T4013] Mem abort info:
[ 3313.874303][ T4013]   ESR = 0x0000000096000006
[ 3313.874305][ T4013]   EC = 0x25: DABT (current EL), IL = 32 bits
[ 3313.874307][ T4013]   SET = 0, FnV = 0
[ 3313.874309][ T4013]   EA = 0, S1PTW = 0
[ 3313.874311][ T4013]   FSC = 0x06: level 2 translation fault
[ 3313.874313][ T4013] Data abort info:
[ 3313.874314][ T4013]   ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000
[ 3313.874316][ T4013]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 3313.874318][ T4013]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 3313.874320][ T4013] user pgtable: 4k pages, 39-bit VAs, pgdp=00000008f2b0a000
..

[ 3313.874332][ T4013] Dumping ftrace buffer:
[ 3313.874334][ T4013]    (ftrace buffer empty)
..
..
[ dd3313.874639][ T4013] CPU: 6 PID: 4013 Comm: InputReader
[ 3313.874648][ T4013] pc : dualshock4_led_get_brightness+0xc/0x74
[ 3313.874653][ T4013] lr : led_update_brightness+0x38/0x60
[ 3313.874656][ T4013] sp : ffffffc0b910bbd0
..
..
[ 3313.874685][ T4013] Call trace:
[ 3313.874687][ T4013]  dualshock4_led_get_brightness+0xc/0x74
[ 3313.874690][ T4013]  brightness_show+0x20/0x4c
[ 3313.874692][ T4013]  dev_attr_show+0x38/0x74
[ 3313.874696][ T4013]  sysfs_kf_seq_show+0xb4/0x130
[ 3313.874700][ T4013]  kernfs_seq_show+0x44/0x54
[ 3313.874703][ T4013]  seq_read_iter+0x158/0x4ec
[ 3313.874705][ T4013]  kernfs_fop_read_iter+0x68/0x1b4
[ 3313.874708][ T4013]  vfs_read+0x1e0/0x2c8
[ 3313.874711][ T4013]  ksys_read+0x78/0xe8
[ 3313.874714][ T4013]  __arm64_sys_read+0x1c/0x2c
[ 3313.874718][ T4013]  invoke_syscall+0x58/0x114
[ 3313.874721][ T4013]  el0_svc_common+0x80/0xe0
[ 3313.874724][ T4013]  do_el0_svc+0x1c/0x28
[ 3313.874727][ T4013]  el0_svc+0x38/0x68
[ 3313.874730][ T4013]  el0t_64_sync_handler+0x68/0xbc
[ 3313.874732][ T4013]  el0t_64_sync+0x1a8/0x1ac

Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
Reviewed-by: Anish Kumar <yesanishhere@gmail.com>
Link: https://lore.kernel.org/r/20241103160527.82487-1-quic_mojha@quicinc.com
Signed-off-by: Lee Jones <lee@kernel.org>
2024-11-06 08:42:59 +00:00
Dmitry RokosovandLee Jones 32360bf6a5 leds: Introduce ordered workqueue for LEDs events instead of system_wq
This allows to setup ordered workqueue for LEDs events. This may be
useful, because default 'system_wq' does not guarantee execution order
of each work_struct, thus for several brightness update requests (for
multiple LEDs), real brightness switch could be in random order.

Yes, for sysfs-based LEDs we have flush_work() call inside
brightness_store() operation, but it's blocking call, so userspace
caller can be blocked at a long time, which means LEDs animation stream
can be broken.

Ordered workqueue has the same behaviour as system_wq + flush_work(),
but all scheduled works are async and userspace caller is not blocked,
which it better for userspace animation scheduling.

Signed-off-by: Alexey Romanov <avromanov@salutedevices.com>
Signed-off-by: Dmitry Rokosov <ddrokosov@salutedevices.com>
Link: https://lore.kernel.org/r/20240903223936.21292-1-ddrokosov@salutedevices.com
[Lee: Couple of style fix-ups]
Signed-off-by: Lee Jones <lee@kernel.org>
2024-11-06 08:11:19 +00:00
Lukasz MajewskiandLee Jones 6b08d07cac leds: trigger: netdev: Add support for tx_err and rx_err notification with LEDs
This patch provides support for enabling blinking of LEDs when RX or TX
errors are detected.

Approach taken in this patch is similar to one for TX or RX data
transmission indication (i.e. TRIGGER_NETDEV_TX/RX attribute).

One can inspect transmission errors with:
ip -s link show eth0

Example LED configuration:
cd /sys/devices/platform/amba_pl@0/a001a000.leds/leds/
echo netdev > mode:blue/trigger && \
echo eth0 > mode:blue/device_name && \
echo 1 > mode:blue/tx_err

Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240710100651.4059887-1-lukma@denx.de
Signed-off-by: Lee Jones <lee@kernel.org>
2024-08-01 13:40:01 +01:00
Lee Jones 59561ccd90 Merge branches 'ib-leds-mfd-6.11', 'ib-leds-platform-power-6.11' and 'ib-mfd-leds-platform-6.11' into ibs-for-leds-merged 2024-06-21 11:54:35 +01:00
Thomas WeißschuhandLee Jones 5f2e950755 leds: core: Introduce led_get_color_name() function
This is similar to the existing led_colors[] array but is safer to use and
usable by everyone.

Getting string representations of color ids is useful for drivers
which are handling color IDs anyways, for example for the multicolor API.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20240613-cros_ec-led-v3-1-500b50f41e0f@weissschuh.net
Signed-off-by: Lee Jones <lee@kernel.org>
2024-06-21 11:41:32 +01:00
Thomas WeißschuhandLee Jones 6b0d3355e5 leds: class: Add flag to avoid automatic renaming of LED devices
Add a mechanism for drivers to opt-out of the automatic device renaming
on conflicts.
Those drivers will provide their own conflict resolution.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20240526-cros_ec-kbd-led-framework-v3-2-ee577415a521@weissschuh.net
Signed-off-by: Lee Jones <lee@kernel.org>
2024-06-14 10:09:40 +01:00
Hans de GoedeandLee Jones 0921a57c91 leds: trigger: Add led_mc_trigger_event() function
Add a new led_mc_trigger_event() function for triggers which want to
change the color of a multi-color LED based on their trigger conditions.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://lore.kernel.org/r/20240531114124.45346-6-hdegoede@redhat.com
Signed-off-by: Lee Jones <lee@kernel.org>
2024-05-31 12:57:42 +01:00
Hans de GoedeandLee Jones 5607ca92e6 leds: core: Add led_mc_set_brightness() function
Add a new led_mc_set_brightness() function for in kernel color/brightness
changing of multi-color LEDs.

led-class-multicolor can be build as a module and led_mc_set_brightness()
will have the builtin callers, so put led_mc_set_brightness() inside
led-core instead, just like how led_set_brightness() is part of the core
and not of the led-class object.

This also adds a new LED_MULTI_COLOR led_classdev flag to allow
led_mc_set_brightness() to verify that it is operating on a multi-color
LED classdev, avoiding casting the passed in LED classdev to a multi-color
LED classdev, when it actually is not a multi-color LED.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://lore.kernel.org/r/20240531114124.45346-5-hdegoede@redhat.com
Signed-off-by: Lee Jones <lee@kernel.org>
2024-05-31 12:57:41 +01:00
Heiner KallweitandLee Jones ab2ab9e69e leds: trigger: audio: Remove this trigger
Now that the audio trigger is fully integrated in
sound/core/control_led.c, we can remove it here.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/1e339779-6d04-4392-8ea2-5592c0fd1aa2@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
2024-03-28 10:40:24 +00:00
Heiner KallweitandLee Jones 822c91e72e leds: trigger: Store brightness set by led_trigger_event()
If a simple trigger is assigned to a LED, then the LED may be off until
the next led_trigger_event() call. This may be an issue for simple
triggers with rare led_trigger_event() calls, e.g. power supply
charging indicators (drivers/power/supply/power_supply_leds.c).
Therefore persist the brightness value of the last led_trigger_event()
call and use this value if the trigger is assigned to a LED.
In addition add a getter for the trigger brightness value.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/b1358b25-3f30-458d-8240-5705ae007a8a@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
2024-03-28 10:39:49 +00:00
Arnd BergmannandLee Jones 08b7dab9f0 leds: Fix ifdef check for gpio_led_register_device()
gpio_led_register_device() is built whenever CONFIG_LEDS_GPIO_REGISTER is
enabled, and this may be used even when CONFIG_NEW_LEDS is turned off.

However, the stub declaration in the header is provided for all configs
without CONFIG_NEW_LEDS, resulting in a build failure:

drivers/leds/leds-gpio-register.c:24:1: error: redefinition of 'gpio_led_register_device'
   24 | gpio_led_register_device(int id, const struct gpio_led_platform_data *pdata)
      | ^
include/linux/leds.h:646:39: note: previous definition is here

Change the #ifdef check to match the definition.
Note: this apparently took years of randconfig builds to hit, since
a number of other drivers just 'select NEW_LEDS' anyway.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240228093834.2230004-1-arnd@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
2024-03-07 08:48:14 +00:00
Arnd BergmannandLee Jones 211f8ec940 leds: Remove led_init_default_state_get() and devm_led_classdev_register_ext() stubs
These two functions have stub implementations that are called when
NEW_LEDS and/or LEDS_CLASS are disabled, theorerically allowing drivers
to optionally use the LED subsystem.

However, this has never really worked because a built-in driver is
unable to link against these functions if the LED class is in a loadable
module. Heiner ran into this problem with a driver that newly gained
a LEDS_CLASS dependency and suggested using an IS_REACHABLE() check.

This is the reverse approach, removing the stub entirely to acknowledge
that it is pointless in its current form, and that not having it avoids
misleading developers into thinking that they can rely on it.

This survived around 1000 randconfig builds to validate that any callers
of the interface already have the correct Kconfig dependency already,
with the exception of the one that Heiner just added.

Cc: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/linux-leds/0f6f432b-c650-4bb8-a1b5-fe3372804d52@gmail.com/T/#u
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240109090715.982332-1-arnd@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
2024-03-07 08:48:02 +00:00
Heiner KallweitandLee Jones c82a1662d4 leds: trigger: Remove unused function led_trigger_rename_static()
This function was added with a8df7b1ab7 ("leds: add led_trigger_rename
function") 11 yrs ago, but it has no users. So remove it.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/d90f30be-f661-4db7-b0b5-d09d07a78a68@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
2023-12-13 15:55:09 +00:00
Daniel GolleandLee Jones 59b3e31e73 leds: trigger: netdev: Extend speeds up to 10G
Add 2.5G, 5G and 10G as available speeds to the netdev LED trigger.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/99e7d3304c6bba7f4863a4a80764a869855f2085.1701143925.git.daniel@makrotopia.org
Signed-off-by: Lee Jones <lee@kernel.org>
2023-12-13 11:24:47 +00:00
Jean-Jacques HiblotandLee Jones c7d80059b0 leds: class: Store the color index in struct led_classdev
Store the color of the LED so that it is not lost after the LED's
name has been composed. This color information can then be exposed to
the user space or used by the LED consumer.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
Link: https://lore.kernel.org/r/20230728153731.3742339-3-jjhiblot@traphandler.com
Signed-off-by: Lee Jones <lee@kernel.org>
2023-08-17 09:00:34 +01:00
Jean-Jacques HiblotandLee Jones afb4815322 leds: Provide devm_of_led_get_optional()
Add an optional variant of devm_of_led_get(). It behaves the same as
devm_of_led_get() except where the LED doesn't exist. In this case,
instead of returning -ENOENT, the function returns NULL.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20230728153731.3742339-2-jjhiblot@traphandler.com
Signed-off-by: Lee Jones <lee@kernel.org>
2023-08-17 09:00:06 +01:00
Linus Torvalds c156d4af43 Merge tag 'leds-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/leds
Pull LED updates from Lee Jones:
 "New Drivers:
   - Add support for Intel Cherry Trail Whiskey Cove PMIC LEDs
   - Add support for Awinic AW20036/AW20054/AW20072 LEDs

  New Device Support:
   - Add support for PMI632 LPG to QCom LPG
   - Add support for PMI8998 to QCom Flash
   - Add support for MT6331, WLEDs and MT6332 to Mediatek MT6323 PMIC

  New Functionality:
   - Implement the LP55xx Charge Pump
   - Add support for suspend / resume to Intel Cherry Trail Whiskey Cove PMIC
   - Add support for breathing mode to Intel Cherry Trail Whiskey Cove PMIC
   - Enable per-pin resolution Pinctrl in LEDs GPIO

  Fix-ups:
   - Allow thread to sleep by switching from spinlock to mutex
   - Add lots of Device Tree bindings / support
   - Adapt relationships / dependencies driven by Kconfig
   - Switch I2C drivers from .probe_new() to .probe()
   - Remove superfluous / duplicate code
   - Replace strlcpy() with strscpy() for efficiency and overflow prevention
   - Staticify various functions
   - Trivial: Fixing coding style
   - Simplify / reduce code

  Bug Fixes:
   - Prevent NETDEV_LED_MODE_LINKUP from being cleared on rename
   - Repair race between led_set_brightness(LED_{OFF,FULL})
   - Fix Oops relating to sleeping in critical sections
   - Clear LED_INIT_DEFAULT_TRIGGER flag when clearing the current trigger
   - Do not leak resources in error handling paths
   - Fix unsigned comparison which can never be negative
   - Provide missing NULL terminating entries in tables
   - Fix misnaming issues"

* tag 'leds-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/leds: (53 commits)
  leds: leds-mt6323: Adjust return/parameter types in wled get/set callbacks
  leds: sgm3140: Add richtek,rt5033-led compatible
  dt-bindings: leds: sgm3140: Document richtek,rt5033 compatible
  dt-bindings: backlight: kinetic,ktz8866: Add missing type for "current-num-sinks"
  dt-bindings: leds: Drop unneeded quotes
  leds: Fix config reference for AW200xx driver
  leds: leds-mt6323: Add support for WLEDs and MT6332
  leds: leds-mt6323: Add support for MT6331 leds
  leds: leds-mt6323: Open code and drop MT6323_CAL_HW_DUTY macro
  leds: leds-mt6323: Drop MT6323_ prefix from macros and defines
  leds: leds-mt6323: Specify registers and specs in platform data
  dt-bindings: leds: leds-mt6323: Document mt6332 compatible
  dt-bindings: leds: leds-mt6323: Document mt6331 compatible
  leds: simatic-ipc-leds-gpio: Introduce more Kconfig switches
  leds: simatic-ipc-leds-gpio: Split up into multiple drivers
  leds: simatic-ipc-leds-gpio: Move two extra gpio pins into another table
  leds: simatic-ipc-leds-gpio: Add terminating entries to gpio tables
  leds: flash: leds-qcom-flash: Fix an unsigned comparison which can never be negative
  leds: cht-wcove: Remove unneeded semicolon
  leds: cht-wcove: Fix an unsigned comparison which can never be negative
  ...
2023-07-03 11:26:05 -07:00
Christian MarangiandJakub Kicinski f22f95b9ff leds: trigger: netdev: add additional specific link duplex mode
Add additional modes for specific link duplex. Use ethtool APIs to get the
current link duplex and enable the LED accordingly. Under netdev event
handler the rtnl lock is already held and is not needed to be set to
access ethtool APIs.

This is especially useful for PHY and Switch that supports LEDs hw
control for specific link duplex.

Add additional modes:
- half_duplex: Turn on LED when link is half duplex
- full_duplex: Turn on LED when link is full duplex

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-21 14:30:46 -07:00
Christian MarangiandJakub Kicinski d5e01266e7 leds: trigger: netdev: add additional specific link speed mode
Add additional modes for specific link speed. Use ethtool APIs to get the
current link speed and enable the LED accordingly. Under netdev event
handler the rtnl lock is already held and is not needed to be set to
access ethtool APIs.

This is especially useful for PHY and Switch that supports LEDs hw
control for specific link speed. (example scenario a PHY that have 2 LED
connected one green and one orange where the green is turned on with
1000mbps speed and orange is turned on with 10mpbs speed)

On mode set from sysfs we check if we have enabled split link speed mode
and reject enabling generic link mode to prevent wrong and redundant
configuration.

Rework logic on the set baseline state to support these new modes to
select if we need to turn on or off the LED.

Add additional modes:
- link_10: Turn on LED when link speed is 10mbps
- link_100: Turn on LED when link speed is 100mbps
- link_1000: Turn on LED when link speed is 1000mbps

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-21 14:30:46 -07:00
Christian MarangiandDavid S. Miller 947acacab5 leds: trigger: netdev: expose netdev trigger modes in linux include
Expose netdev trigger modes to make them accessible by LED driver that
will support netdev trigger for hw control.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-31 09:42:09 +01:00
Andrew LunnandDavid S. Miller 052c38eb17 leds: add API to get attached device for LED hw control
Some specific LED triggers blink the LED based on events from a device
or subsystem.
For example, an LED could be blinked to indicate a network device is
receiving packets, or a disk is reading blocks. To correctly enable and
request the hw control of the LED, the trigger has to check if the
network interface or block device configured via a /sys/class/led file
match the one the LED driver provide for hw control for.

Provide an API call to get the device which the LED blinks for.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-31 09:42:08 +01:00
Christian MarangiandDavid S. Miller ed554d3f94 leds: add APIs for LEDs hw control
Add an option to permit LED driver to declare support for a specific
trigger to use hw control and setup the LED to blink based on specific
provided modes.

Add APIs for LEDs hw control. These functions will be used to activate
hardware control where a LED will use the provided flags, from an
unique defined supported trigger, to setup the LED to be driven by
hardware.

Add hw_control_is_supported() to ask the LED driver if the requested
mode by the trigger are supported and the LED can be setup to follow
the requested modes.

Deactivate hardware blink control by setting brightness to LED_OFF via
the brightness_set() callback.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-31 09:42:08 +01:00
Hans de GoedeandLee Jones 22720a87d0 leds: Fix oops about sleeping in led_trigger_blink()
led_trigger_blink() calls led_blink_set() from a RCU read-side critical
section so led_blink_set() must not sleep. Note sleeping was not allowed
before the switch to RCU either because a spinlock was held before.

led_blink_set() does not sleep when sw-blinking is used, but
many LED controller drivers with hw blink support have a blink_set
function which may sleep, leading to an oops like this one:

[  832.605062] ------------[ cut here ]------------
[  832.605085] Voluntary context switch within RCU read-side critical section!
[  832.605119] WARNING: CPU: 2 PID: 370 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x4ee/0x690
<snip>
[  832.606453] Call Trace:
[  832.606466]  <TASK>
[  832.606487]  __schedule+0x9f/0x1480
[  832.606527]  schedule+0x5d/0xe0
[  832.606549]  schedule_timeout+0x79/0x140
[  832.606572]  ? __pfx_process_timeout+0x10/0x10
[  832.606599]  wait_for_completion_timeout+0x6f/0x140
[  832.606627]  i2c_dw_xfer+0x101/0x460
[  832.606659]  ? psi_group_change+0x168/0x400
[  832.606680]  __i2c_transfer+0x172/0x6d0
[  832.606709]  i2c_smbus_xfer_emulated+0x27d/0x9c0
[  832.606732]  ? __schedule+0x430/0x1480
[  832.606753]  ? preempt_count_add+0x6a/0xa0
[  832.606778]  ? get_nohz_timer_target+0x18/0x190
[  832.606796]  ? lock_timer_base+0x61/0x80
[  832.606817]  ? preempt_count_add+0x6a/0xa0
[  832.606842]  __i2c_smbus_xfer+0xa2/0x3f0
[  832.606862]  i2c_smbus_xfer+0x66/0xf0
[  832.606882]  i2c_smbus_read_byte_data+0x41/0x70
[  832.606901]  ? _raw_spin_unlock_irqrestore+0x23/0x40
[  832.606922]  ? __pm_runtime_suspend+0x46/0xc0
[  832.606946]  cht_wc_byte_reg_read+0x2e/0x60
[  832.606972]  _regmap_read+0x5c/0x120
[  832.606997]  _regmap_update_bits+0x96/0xc0
[  832.607023]  regmap_update_bits_base+0x5b/0x90
[  832.607053]  cht_wc_leds_brightness_get+0x412/0x910 [leds_cht_wcove]
[  832.607094]  led_blink_setup+0x28/0x100
[  832.607119]  led_trigger_blink+0x40/0x70
[  832.607145]  power_supply_update_leds+0x1b7/0x1c0
[  832.607174]  power_supply_changed_work+0x67/0xe0
[  832.607198]  process_one_work+0x1c8/0x3c0
[  832.607222]  worker_thread+0x4d/0x380
[  832.607243]  ? __pfx_worker_thread+0x10/0x10
[  832.607258]  kthread+0xe9/0x110
[  832.607279]  ? __pfx_kthread+0x10/0x10
[  832.607300]  ret_from_fork+0x2c/0x50
[  832.607337]  </TASK>
[  832.607344] ---[ end trace 0000000000000000 ]---

Add a new led_blink_set_nosleep() function which defers the actual
led_blink_set() call to a workqueue when necessary to fix this.

This also fixes an existing race where a pending led_set_brightness() has
been deferred to set_brightness_work and might then race with a later
led_cdev->blink_set() call. Note this race is only an issue with triggers
mixing led_trigger_event() and led_trigger_blink() calls, sysfs API
calls and led_trigger_blink_oneshot() are not affected.

Note rather then adding a separate blink_set_blocking callback this uses
the presence of the already existing brightness_set_blocking callback to
detect if the blinking call should be deferred to set_brightness_work.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Tested-by: Yauhen Kharuzhy <jekhor@gmail.com>
Link: https://lore.kernel.org/r/20230510162234.291439-4-hdegoede@redhat.com
Signed-off-by: Lee Jones <lee@kernel.org>
2023-05-25 12:16:31 +01:00