On 06/21/2016 05:28 PM, Jacek Anaszewski wrote:

Hi Florian,

Thanks for the patch. I have two remarks below.

On 06/21/2016 09:29 AM, Florian Vaussard wrote:

quoted

Add device tree binding documentation for On Semiconductor NCP5623 I2C
LED driver. The driver can independently control the PWM of the 3
channels with 32 levels of intensity.

The current delivered by the current source can be controlled using the
led-max-microamp property. In order to control this value, it is also
necessary to know the current on the Iref pin, hence the
onnn,led-iref-microamp property. It is usually set using an external
bias resistor, following Iref = Vref/Rbias with Vref=0.6V.

Signed-off-by: Florian Vaussard <redacted>
---
  .../devicetree/bindings/leds/leds-ncp5623.txt      | 44
++++++++++++++++++++++
  1 file changed, 44 insertions(+)
  create mode 100644
Documentation/devicetree/bindings/leds/leds-ncp5623.txt

diff --git a/Documentation/devicetree/bindings/leds/leds-ncp5623.txt

b/Documentation/devicetree/bindings/leds/leds-ncp5623.txt
new file mode 100644
index 0000000..0dc8345

--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-ncp5623.txt

@@ -0,0 +1,44 @@
+* ON Semiconductor - NCP5623 3-Channel LED Driver
+
+The NCP5623 is a 3-channel I2C LED driver. The brightness of each
+channel can be independently set using 32 levels. Each LED is

represented
+as a sub-node of the device.
+
+Required properties:
+  - compatible: Should be "onnn,ncp5623"
+  - reg: I2C slave address (fixed to 0x38)
+  - #address-cells: must be 1
+  - #size-cells: must be 0
+  - onnn,led-iref-microamp: Current on the Iref pin in microampere

I think that you don't need this property. Just provide the formula for
calculating led-max-microamp value, similarly as you're doing that in
the commit message.

quoted

+  - led-max-microamp: Desired maximum current for each LED in
microampere
+                      (maximum 30000uA)

Please add instead of (maximum ...):

Valid values: min - max, step by N (rounded {up|down})

E.g.

Valid values: 10000 - 30000, step by 1000 (rounded down)

quoted

+
+LED sub-node properties:
+  - reg : LED channel number (0..2)
+  - For other LED properties see:
+      Documentation/devicetree/bindings/leds/common.txt
+
+Example:
+
+led1: ncp5623@38 {
+    #address-cells = <1>;
+    #size-cells = <0>;
+    compatible = "onnn,ncp5623";
+    reg = <0x38>;
+
+    led1_r@0 {
+        label = "ncp:power:red";
+        reg = <0>;
+        linux,default-trigger = "default-on";

Please add also led-max-microamp to all child nodes in this example.

quoted

+    };
+
+    led1_b@1 {
+        label = "ncp:power:blue";
+        reg = <1>;
+    };
+
+    led1_g@2 {
+        label = "ncp:power:green";
+        reg = <2>;
+    };
+};

-- 
Best regards,
Jacek Anaszewski