diff mbox series

[v4,2/7] dt-bindings: ti-lmu: Modify dt bindings for the LM3697

Message ID 20181023170623.31820-2-dmurphy@ti.com
State New
Headers show
Series None | expand

Commit Message

Dan Murphy Oct. 23, 2018, 5:06 p.m. UTC 
The LM3697 is a single function LED driver. The single function LED
driver needs to reside in the LED directory as a dedicated LED driver
and not as a MFD device.  The device does have common brightness and ramp
features and those can be accomodated by a TI LMU framework.

The LM3697 dt binding needs to be moved from the ti-lmu.txt and a dedicated
LED dt binding needs to be added.  The new LM3697 LED dt binding will then
reside in the Documentation/devicetree/bindings/leds directory and follow the
current LED and general bindings guidelines.

Signed-off-by: Dan Murphy <dmurphy@ti.com>

---

v4 - Squashed removal and addition of the dt bindings into a single patch - https://lore.kernel.org/patchwork/patch/998703/

 .../devicetree/bindings/leds/leds-lm3697.txt  | 98 +++++++++++++++++++
 .../devicetree/bindings/mfd/ti-lmu.txt        | 26 +----
 2 files changed, 99 insertions(+), 25 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-lm3697.txt

-- 
2.19.0

Comments

Pavel Machek Oct. 26, 2018, 8:30 a.m. UTC | #1 
Hi!

> >>>>> +Optional child properties:

> >>>>> +	- runtime-ramp-up-msec: Current ramping from one brightness level to

> >>>>> +				the a higher brightness level.

> >>>>> +				Range from 2048 us - 117.44 s


> This is this problem with the Device Tree's scope of responsibility.

> It is defined as a means for "describing the hardware", but often

> this rule is abused by the properties that fall into "configuration"

> category. E.g. default-state, retain-state-suspended from leds-gpio.txt

> or linux-default-trigger from common LED bindings.


I always assumed that ramp-up time is there because hardware (power
supply?) can not handle "too fast" switching. Missing capacitors or
something. If so, this needs to be in device tree.

If not, it indeed does not belong to device tree.

> In some cases this is justified. The question is whether it is something

> that necessarily needs to be configured on driver probing? If not, then

> I'd go for sysfs interface.


While this would be useful for hardware accelerated patterns, I doubt
we want to make it configurable without that support.

									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/leds/leds-lm3697.txt b/Documentation/devicetree/bindings/leds/leds-lm3697.txt
new file mode 100644
index 000000000000..4bb2ed51025b
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-lm3697.txt
@@ -0,0 +1,98 @@ 
+* Texas Instruments - LM3697 Highly Efficient White LED Driver
+
+The LM3697 11-bit LED driver provides high-
+performance backlight dimming for 1, 2, or 3 series
+LED strings while delivering up to 90% efficiency.
+
+This device is suitable for display and keypad Lighting
+
+Required properties:
+	- compatible:
+		"ti,lm3697"
+	- reg :  I2C slave address
+	- #address-cells : 1
+	- #size-cells : 0
+
+Optional properties:
+	- enable-gpios : GPIO pin to enable/disable the device
+	- vled-supply : LED supply
+
+Required child properties:
+	- reg : 0 - LED is Controlled by bank A
+		1 - LED is Controlled by bank B
+	- led-sources : Indicates which HVLED string is associated to which
+			control bank.  Each element in the array is associated
+			with a specific HVLED string.  Element 0 is HVLED1,
+			element 1 is HVLED2 and element 2 HVLED3.
+			Additional information is contained
+			in Documentation/devicetree/bindings/leds/common.txt
+			0 - HVLED is not active in this control bank
+			1 - HVLED string is controlled by this control bank
+
+Optional child properties:
+	- runtime-ramp-up-msec: Current ramping from one brightness level to
+				the a higher brightness level.
+				Range from 2048 us - 117.44 s
+	- runtime-ramp-down-msec: Current ramping from one brightness level to
+				  the a lower brightness level.
+				  Range from 2048 us - 117.44 s
+	- label : see Documentation/devicetree/bindings/leds/common.txt
+	- linux,default-trigger :
+	   see Documentation/devicetree/bindings/leds/common.txt
+
+Example:
+
+HVLED string 1 and 3 are controlled by control bank A and HVLED 2 string is
+controlled by control bank B.
+
+led-controller@36 {
+	compatible = "ti,lm3697";
+	reg = <0x36>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	enable-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>;
+	vled-supply = <&vbatt>;
+
+	led@0 {
+		reg = <0>;
+		led-sources = <1 0 1>;
+		runtime-ramp-up-msec = <5000>;
+		runtime-ramp-down-msec = <1000>;
+		label = "white:first_backlight_cluster";
+		linux,default-trigger = "backlight";
+	};
+
+	led@1 {
+		reg = <1>;
+		led-sources = <0 1 0>;
+		runtime-ramp-up-msec = <500>;
+		runtime-ramp-down-msec = <1000>;
+		label = "white:second_backlight_cluster";
+		linux,default-trigger = "backlight";
+	};
+}
+
+All HVLED strings controlled by control bank A
+
+led-controller@36 {
+	compatible = "ti,lm3697";
+	reg = <0x36>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	enable-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>;
+	vled-supply = <&vbatt>;
+
+	led@0 {
+		reg = <0>;
+		led-sources = <1 1 1>;
+		runtime-ramp-up-msec = <500>;
+		runtime-ramp-down-msec = <1000>;
+		label = "white:backlight_cluster";
+		linux,default-trigger = "backlight";
+	};
+}
+
+For more product information please see the link below:
+http://www.ti.com/lit/ds/symlink/lm3697.pdf
diff --git a/Documentation/devicetree/bindings/mfd/ti-lmu.txt b/Documentation/devicetree/bindings/mfd/ti-lmu.txt
index c885cf89b8ce..920f910be4e9 100644
--- a/Documentation/devicetree/bindings/mfd/ti-lmu.txt
+++ b/Documentation/devicetree/bindings/mfd/ti-lmu.txt
@@ -9,7 +9,6 @@  TI LMU driver supports lighting devices below.
   LM3632       Backlight and regulator
   LM3633       Backlight, LED and fault monitor
   LM3695       Backlight
-  LM3697       Backlight and fault monitor
 
 Required properties:
   - compatible: Should be one of:
@@ -18,11 +17,10 @@  Required properties:
                 "ti,lm3632"
                 "ti,lm3633"
                 "ti,lm3695"
-                "ti,lm3697"
   - reg: I2C slave address.
          0x11 for LM3632
          0x29 for LM3631
-         0x36 for LM3633, LM3697
+         0x36 for LM3633
          0x38 for LM3532
          0x63 for LM3695
 
@@ -38,7 +36,6 @@  Optional nodes:
     Required properties:
       - compatible: Should be one of:
                     "ti,lm3633-fault-monitor"
-                    "ti,lm3697-fault-monitor"
   - leds: LED properties for LM3633. Please refer to [2].
   - regulators: Regulator properties for LM3631 and LM3632.
                 Please refer to [3].
@@ -220,24 +217,3 @@  lm3695@63 {
 		};
 	};
 };
-
-lm3697@36 {
-	compatible = "ti,lm3697";
-	reg = <0x36>;
-
-	enable-gpios = <&pioC 2 GPIO_ACTIVE_HIGH>;
-
-	backlight {
-		compatible = "ti,lm3697-backlight";
-
-		lcd {
-			led-sources = <0 1 2>;
-			ramp-up-msec = <200>;
-			ramp-down-msec = <200>;
-		};
-	};
-
-	fault-monitor {
-		compatible = "ti,lm3697-fault-monitor";
-	};
-};