summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--Documentation/devicetree/bindings/pwm/pwm.txt7
-rw-r--r--include/dt-bindings/pwm/pwm.h14
2 files changed, 18 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/pwm/pwm.txt b/Documentation/devicetree/bindings/pwm/pwm.txt
index 06e67247859..8556263b850 100644
--- a/Documentation/devicetree/bindings/pwm/pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm.txt
@@ -43,13 +43,14 @@ because the name "backlight" would be used as fallback anyway.
pwm-specifier typically encodes the chip-relative PWM number and the PWM
period in nanoseconds.
-Optionally, the pwm-specifier can encode a number of flags in a third cell:
-- bit 0: PWM signal polarity (0: normal polarity, 1: inverse polarity)
+Optionally, the pwm-specifier can encode a number of flags (defined in
+<dt-bindings/pwm/pwm.h>) in a third cell:
+- PWM_POLARITY_INVERTED: invert the PWM signal polarity
Example with optional PWM specifier for inverse polarity
bl: backlight {
- pwms = <&pwm 0 5000000 1>;
+ pwms = <&pwm 0 5000000 PWM_POLARITY_INVERTED>;
pwm-names = "backlight";
};
diff --git a/include/dt-bindings/pwm/pwm.h b/include/dt-bindings/pwm/pwm.h
new file mode 100644
index 00000000000..96f49e82253
--- /dev/null
+++ b/include/dt-bindings/pwm/pwm.h
@@ -0,0 +1,14 @@
+/*
+ * This header provides constants for most PWM bindings.
+ *
+ * Most PWM bindings can include a flags cell as part of the PWM specifier.
+ * In most cases, the format of the flags cell uses the standard values
+ * defined in this header.
+ */
+
+#ifndef _DT_BINDINGS_PWM_PWM_H
+#define _DT_BINDINGS_PWM_PWM_H
+
+#define PWM_POLARITY_INVERTED (1 << 0)
+
+#endif