2 files changed, 30 insertions, 1 deletions

diff --git a/Documentation/devicetree/bindings/pwm/bcm-kona-pwm.txt b/Documentation/devicetree/bindings/pwm/bcm-kona-pwm.txt
new file mode 100644
index 000000000000..8eae9fe7841c
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/bcm-kona-pwm.txt
@@ -0,0 +1,21 @@
+Broadcom Kona PWM controller device tree bindings
+
+This controller has 6 channels.
+
+Required Properties :
+- compatible: should contain "brcm,kona-pwm"
+- reg: physical base address and length of the controller's registers
+- clocks: phandle + clock specifier pair for the external clock
+- #pwm-cells: Should be 3. See pwm.txt in this directory for a
+  description of the cells format.
+
+Refer to clocks/clock-bindings.txt for generic clock consumer properties.
+
+Example:
+
+pwm: pwm@3e01a000 {
+        compatible = "brcm,bcm11351-pwm", "brcm,kona-pwm";
+        reg = <0x3e01a000 0xc4>;
+        clocks = <&pwm_clk>;
+        #pwm-cells = <3>;
+};
diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt
index 93cb97974986..ca895fd211e4 100644
--- a/Documentation/pwm.txt
+++ b/Documentation/pwm.txt
@@ -19,7 +19,8 @@ should instead register a static mapping that can be used to match PWM
 consumers to providers, as given in the following example:
 
         static struct pwm_lookup board_pwm_lookup[] = {
-                PWM_LOOKUP("tegra-pwm", 0, "pwm-backlight", NULL),
+                PWM_LOOKUP("tegra-pwm", 0, "pwm-backlight", NULL,
+                           50000, PWM_POLARITY_NORMAL),
         };
 
         static void __init board_init(void)
@@ -97,6 +98,13 @@ pwm_chip as argument which provides a description of the PWM chip, the
 number of PWM devices provided by the chip and the chip-specific
 implementation of the supported PWM operations to the framework.
 
+When implementing polarity support in a PWM driver, make sure to respect the
+signal conventions in the PWM framework. By definition, normal polarity
+characterizes a signal starts high for the duration of the duty cycle and
+goes low for the remainder of the period. Conversely, a signal with inversed
+polarity starts low for the duration of the duty cycle and goes high for the
+remainder of the period.
+
 Locking
 -------