On 04/11/2016 08:23 AM, Phil Reid wrote:
On 7/04/2016 10:02 PM, Jacek Anaszewski wrote:
Hi Phil,
Thanks for the update. Few more remarks below.
On 04/07/2016 09:22 AM, Phil Reid wrote:
This patch adds basic device tree support for the pca9532 LEDs.
Signed-off-by: Phil Reid <preid@xxxxxxxxxxxxxxxxx>
---
.../devicetree/bindings/leds/leds-pca9532.txt | 42 +++++++++++++
drivers/leds/leds-pca9532.c | 69
++++++++++++++++++++--
include/dt-bindings/leds/leds-pca9532.h | 23 ++++++++
include/linux/leds-pca9532.h | 18 ++----
4 files changed, 135 insertions(+), 17 deletions(-)
create mode 100644
Documentation/devicetree/bindings/leds/leds-pca9532.txt
create mode 100644 include/dt-bindings/leds/leds-pca9532.h
diff --git a/Documentation/devicetree/bindings/leds/leds-pca9532.txt
b/Documentation/devicetree/bindings/leds/leds-pca9532.txt
new file mode 100644
index 0000000..284b96c
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-pca9532.txt
@@ -0,0 +1,42 @@
+*NXP - pca9532 PWM LED Driver
+
+The PCA9532 family is SMBus I/O expander optimized for dimming LEDs.
+The PWM support 256 steps.
+
+Required properties:
+ - compatible:
+ "nxp,pca9530"
+ "nxp,pca9531"
+ "nxp,pca9532"
+ "nxp,pca9533"
+ - reg - I2C slave address
+
+Each led is represented as a sub-node of the nxp,pca9530.
+
+Optional sub-node properties:
+ - label: Name for this LED. If omitted, the label is taken from
the node name.
Please also add a reference to common led bindings, as this property is
documented there:
"(see Documentation/devicetree/bindings/leds/common.txt):"
done.
+ - type: Output configuration, see
dt-bindings/leds/leds-pca9532.h (default NONE)
+ - state: Initial LED state (default OFF)
We already have "default-on" trigger for this purpose.
Not sure it does exactly the same thing.
This setting also associates a led with a particular PWM controller.
The chip has 2 shared PWM that each led can be controlled by.
default-on trigger sets the LED to max_brightness on init.
As I see pca9532_set_brightness() sets PCA9532_ON state if
passed LED_FULL and uses PCA9532_PWM0 for other values
greater than zero.
So, maybe it would make more sense if we used default-on trigger to
initialize LED to LED_FULL on init, but provide another DT property
'default-pwm' to determine which PWM block should be used by default?
Currently I see that driver uses only PWM0:
led->state = PCA9532_PWM0; /* Thecus: hardcode one pwm */
Alternatively the driver could expose a dedicated sysfs attribute
for changing the default pwm. This is of course out of this patch
scope.
--
Best regards,
Jacek Anaszewski
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