On Mon, Jun 27, 2016 at 10:11:04AM +0200, Jacek Anaszewski wrote: > Hi Florian, > > On 06/27/2016 09:03 AM, Florian Vaussard wrote: > >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 also be controlled. To > >do so, the led-max-microamp property is used by each LED sub-node. The > >maximum value is then found and used as a limit to compute the final > >intensity of the current source. If a LED happens to have a lower limit, > >the PWM is then used to limit the current to the requested value. > > > >In order to control the current source, 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 <florian.vaussard@xxxxxxxxxx> > >--- > > .../devicetree/bindings/leds/leds-ncp5623.txt | 60 ++++++++++++++++++++++ > > 1 file changed, 60 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..77dd7ad > >--- /dev/null > >+++ b/Documentation/devicetree/bindings/leds/leds-ncp5623.txt > >@@ -0,0 +1,60 @@ > >+* 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. It depends > >+ on the value of the external bias resistor Rbias, following > >+ Iref = Vref / Rbias with Vref = 0.6V. This is used to set the intensity of > >+ the current that can be provided by the internal current source, based on > >+ the maximum current permitted by LED sub-nodes (see below), but no more than > >+ Imax = 2400 * Iref. > >+ > >+LED sub-nodes > >+============= > >+ > >+Required properties: > >+ - reg : LED channel number (0..2) > >+ - led-max-microamp: Maximum allowable current inside the LED in microampere. > >+ This property is used to limit the PWM ratio, based on the intensity of the > >+ internal current source (see above). > >+ > >+Optional properties: > >+ - label: Used for naming LEDs > > Instead of the above description use same reference to common led > bindings as below. > > >+ - default-trigger: see Documentation/devicetree/bindings/leds/common.txt And this is missing the linux prefix. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
