On 04/08/2015 05:15 PM, Sylwester Nawrocki wrote:
On 08/04/15 16:31, Jacek Anaszewski wrote:
Properties defining maximum values for LED currents and timeout should
be mandatory to avoid the risk of hardware damage. This patch fixes
the issue.
Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
Documentation/devicetree/bindings/leds/common.txt | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt
index 747c538..e478ac6 100644
--- a/Documentation/devicetree/bindings/leds/common.txt
+++ b/Documentation/devicetree/bindings/leds/common.txt
@@ -10,6 +10,17 @@ can influence the way of the LED device initialization, the LED components
have to be tightly coupled with the LED device binding. They are represented
by child nodes of the parent LED device binding.
+Required properties for child nodes:
These properties are mandatory only for LEDs with Flash/Torch capabilities,
aren't they?
flash-max-microamp and flash-timeout-us properties description mention
that they refer to flash LEDs. Perhaps this should be made indeed more
explicit.
> Requiring those properties for all led nodes would make all
current dtses not compliant with the DT binding specification AFAICT.
I was also worrying about making led-max-microamp required, but others
didn't share my objections. I think that we have to reexamine this.
Please refer to the discussion under [PATCH v4]. The role of this
led-max-microamp property would be preventing hardware damage.
How about:
"Required properties for child nodes for LEDs with Flash/Torch capabilities:" ?
+- led-max-microamp : Maximum LED supply current in microamperes
+ (torch LED for flash devices). Controllers that have no
+ configurable current can omit this property.
+- flash-max-microamp : Maximum flash LED supply current in microamperes.
+- flash-timeout-us : Timeout in microseconds after which the flash
+ LED is turned off.
+
+Above properties determine a LED driver IC settings required for safe
+operation. They should be also used as the initial settings for the IC.
Shouldn't "Controllers that have no configurable current can omit this
property" refer to both led-max-microamp and flash-max-microamp?
>
I would drop the "Above...for the IC." paragraph and instead add something like:
"For controllers that have no configurable current the led-max-microamp,
flash-max-microamp properties respectively can be omitted. For controllers that
have no configurable timeout the flash-timeout-us property can be omitted."
Are we going to avoid mentioning about their role in preventing
hardware damage (former "for safe operation" sequence)?
--
Best Regards,
Jacek Anaszewski
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