This adds device tree binding documentation for the Broadcom BCM6328 LED controller.
Signed-off-by: Álvaro Fernández Rojas <noltari@xxxxxxxxx>
Signed-off-by: Jonas Gorski <jogo@xxxxxxxxxxx>
---
v4: introduce changes suggested by Jacek
- Follow Documentation convention.
v3: introduce changes suggested by Jacek
- Revert compatible string to "brcm,bcm6328-leds".
- Improved description.
- Renamed normal LEDs to hardware controlled.
- Explain that LEDs are active high by default on active-low optional property.
- Properties are now grouped depending on the type of LED and optional requirement.
- Added more examples to explain hardware controlled LEDs and activity/link selection.
v2: Introduce changes suggested by Florian and Jonas.
- Change compatible string to "brcm,bcm6328-leds-ctrl".
- Make valid LEDs statement more strict.
- Remove compatible strings from LED subnodes.
- Clarify that LEDs are active high by default.
- Add a better description for brcm,link-signal-sources and brcm,activity-signal-sources.
.../devicetree/bindings/leds/leds-bcm6328.txt | 309 +++++++++++++++++++++
1 file changed, 309 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/leds-bcm6328.txt
diff --git a/Documentation/devicetree/bindings/leds/leds-bcm6328.txt b/Documentation/devicetree/bindings/leds/leds-bcm6328.txt
new file mode 100644
index 0000000..f9e36ad
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-bcm6328.txt
@@ -0,0 +1,309 @@
+LEDs connected to Broadcom BCM6328 controller
+
+This controller is present on BCM6318, BCM6328, BCM6362 and BCM63268.
+In these SoCs it's possible to control LEDs both as GPIOs or by hardware.
+However, on some devices there are Serial LEDs (LEDs connected to a 74x164
+controller), which can either be controlled by software (exporting the 74x164
+as spi-gpio. See Documentation/devicetree/bindings/gpio/gpio-74x164.txt), or
+by hardware using this driver.
+Some of these Serial LEDs are hardware controlled (e.g. ethernet LEDs) and
+exporting the 74x164 as spi-gpio prevents those LEDs to be hardware
+controlled, so the only chance to keep them working is by using this driver.
+
+BCM6328 LED controller has a HWDIS register, which controls whether a LED
+should be controlled by a hardware signal instead of the MODE register value,
+with 0 meaning hardware control enabled and 1 hardware control disabled. This
+is usually 1:1 for hardware to LED signals, but through the activity/link
+registers you have some limited control over rerouting the LEDs (as
+explained later in brcm,link-signal-sources). Even if a LED is hardware
+controlled you are still able to make it blink or light it up if it isn't,
+but you can't turn it off if the hardware decides to light it up. For this
+reason, hardware controlled LEDs aren't registered as LED class devices.
+
+Required properties:
+ - compatible : should be "brcm,bcm6328-leds".
+ - #address-cells : must be 1.
+ - #size-cells : must be 0.
+ - reg : BCM6328 LED controller address and size.
+
+Optional properties:
+ - brcm,serial-leds : Boolean, enables Serial LEDs.
+ Default : false
+
+Each LED is represented as a sub-node of the brcm,bcm6328-leds device.
+
+LED sub-node required properties:
+ - reg : LED pin number (only LEDs 0 to 23 are valid).
+
+LED sub-node optional properties:
+ a) Optional properties for sub-nodes related to software controlled LEDs:
+ - label : see Documentation/devicetree/bindings/leds/common.txt
+ - active-low : Boolean, makes LED active low.
+ Default : false
+ - default-state : see
+ Documentation/devicetree/bindings/leds/leds-gpio.txt
+ - linux,default-trigger : see
+ Documentation/devicetree/bindings/leds/common.txt
+
+ b) Optional properties for sub-nodes related to hardware controlled LEDs:
+ - brcm,hardware-controlled : Boolean, makes this LED hardware controlled.
+ Default : false
+ - brcm,link-signal-sources : An array of hardware link
+ signal sources. Up to four link hardware signals can get muxed into
+ these LEDs. Only valid for LEDs 0 to 7, where LED signals 0 to 3 may
+ be muxed to LEDs 0 to 3, and signals 4 to 7 may be muxed to LEDs
+ 4 to 7. A signal can be muxed to more than one LED, and one LED can
+ have more than one source signal.
+ - brcm,activity-signal-sources : An array of hardware activity
+ signal sources. Up to four activity hardware signals can get muxed into
+ these LEDs. Only valid for LEDs 0 to 7, where LED signals 0 to 3 may
+ be muxed to LEDs 0 to 3, and signals 4 to 7 may be muxed to LEDs
+ 4 to 7. A signal can be muxed to more than one LED, and one LED can
+ have more than one source signal.
+
+Examples:
+Scenario 1 : BCM6328 with 4 EPHY LEDs
+ leds0: led-controller@10000800 {
+ compatible = "brcm,bcm6328-leds";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0x10000800 0x24>;
+
+ alarm_red@2 {
+ reg = <2>;
+ active-low;
+ label = "red:alarm";
+ };
+ inet_green@3 {
+ reg = <3>;
+ active-low;
+ label = "green:inet";
+ };
+ power_green@4 {
+ reg = <4>;
+ active-low;
+ label = "green:power";
+ default-state = "on";
+ };
+ ephy0_spd@17 {
+ reg = <17>;
+ brcm,hardware-controlled;
+ };
+ ephy1_spd@18 {
+ reg = <18>;
+ brcm,hardware-controlled;
+ };
+ ephy2_spd@19 {
+ reg = <19>;
+ brcm,hardware-controlled;
+ };
+ ephy3_spd@20 {
+ reg = <20>;
+ brcm,hardware-controlled;
+ };
+ };
+
+Scenario 2 : BCM63268 with Serial/GPHY0 LEDs
+ leds0: led-controller@10001900 {
+ compatible = "brcm,bcm6328-leds";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0x10001900 0x24>;
+ brcm,serial-leds;
+
+ gphy0_spd0@0 {
+ reg = <0>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <0>;
+ };
+ gphy0_spd1@1 {
+ reg = <1>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <1>;
+ };
+ inet_red@2 {
+ reg = <2>;
+ active-low;
+ label = "red:inet";
+ };
+ dsl_green@3 {
+ reg = <3>;
+ active-low;
+ label = "green:dsl";
+ };
+ usb_green@4 {
+ reg = <4>;
+ active-low;
+ label = "green:usb";
+ };
+ wps_green@7 {
+ reg = <7>;
+ active-low;
+ label = "green:wps";
+ };
+ inet_green@8 {
+ reg = <8>;
+ active-low;
+ label = "green:inet";
+ };
+ ephy0_act@9 {
+ reg = <9>;
+ brcm,hardware-controlled;
+ };
+ ephy1_act@10 {
+ reg = <10>;
+ brcm,hardware-controlled;
+ };
+ ephy2_act@11 {
+ reg = <11>;
+ brcm,hardware-controlled;
+ };
+ gphy0_act@12 {
+ reg = <12>;
+ brcm,hardware-controlled;
+ };
+ ephy0_spd@13 {
+ reg = <13>;
+ brcm,hardware-controlled;
+ };
+ ephy1_spd@14 {
+ reg = <14>;
+ brcm,hardware-controlled;
+ };
+ ephy2_spd@15 {
+ reg = <15>;
+ brcm,hardware-controlled;
+ };
+ power_green@20 {
+ reg = <20>;
+ active-low;
+ label = "green:power";
+ default-state = "on";
+ };
+ };
+
+Scenario 3 : BCM6362 with 1 LED for each EPHY
+ leds0: led-controller@10001900 {
+ compatible = "brcm,bcm6328-leds";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0x10001900 0x24>;
+
+ usb@0 {
+ reg = <0>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <0>;
+ brcm,activity-signal-sources = <0>;
+ /* USB link/activity routed to USB LED */
+ };
+ inet@1 {
+ reg = <1>;
+ brcm,hardware-controlled;
+ brcm,activity-signal-sources = <1>;
+ /* INET activity routed to INET LED */
+ };
+ ephy0@4 {
+ reg = <4>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <4>;
+ /* EPHY0 link routed to EPHY0 LED */
+ };
+ ephy1@5 {
+ reg = <5>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <5>;
+ /* EPHY1 link routed to EPHY1 LED */
+ };
+ ephy2@6 {
+ reg = <6>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <6>;
+ /* EPHY2 link routed to EPHY2 LED */
+ };
+ ephy3@7 {
+ reg = <7>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <7>;
+ /* EPHY3 link routed to EPHY3 LED */
+ };
+ power_green@20 {
+ reg = <20>;
+ active-low;
+ label = "green:power";
+ default-state = "on";
+ };
+ };
+
+Scenario 4 : BCM6362 with 1 LED for all EPHYs
+ leds0: led-controller@10001900 {
+ compatible = "brcm,bcm6328-leds";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0x10001900 0x24>;
+
+ usb@0 {
+ reg = <0>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <0 1>;
+ brcm,activity-signal-sources = <0 1>;
+ /* USB/INET link/activity routed to USB LED */
+ };
+ ephy@4 {
+ reg = <4>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <4 5 6 7>;
+ /* EPHY0/1/2/3 link routed to EPHY0 LED */
+ };
+ power_green@20 {
+ reg = <20>;
+ active-low;
+ label = "green:power";
+ default-state = "on";
+ };
+ };
+
+Scenario 5 : BCM6362 with EPHY LEDs swapped
+ leds0: led-controller@10001900 {
+ compatible = "brcm,bcm6328-leds";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0x10001900 0x24>;
+
+ usb@0 {
+ reg = <0>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <0>;
+ brcm,activity-signal-sources = <0 1>;
+ /* USB link/act and INET act routed to USB LED */
+ };
+ ephy0@4 {
+ reg = <4>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <7>;
+ /* EPHY3 link routed to EPHY0 LED */
+ };
+ ephy1@5 {
+ reg = <5>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <6>;
+ /* EPHY2 link routed to EPHY1 LED */
+ };
+ ephy2@6 {
+ reg = <6>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <5>;
+ /* EPHY1 link routed to EPHY2 LED */
+ };
+ ephy3@7 {
+ reg = <7>;
+ brcm,hardware-controlled;
+ brcm,link-signal-sources = <4>;
+ /* EPHY0 link routed to EPHY3 LED */
+ };
+ power_green@20 {
+ reg = <20>;
+ active-low;
+ label = "green:power";
+ default-state = "on";
+ };
+ };
--
1.9.1
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