@@ -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";
};
new file mode 100644
@@ -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
Define a PWM_POLARITY_INVERTED macro in include/dt-bindings/pwm/pwm.h to be used by device tree sources. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> --- Documentation/devicetree/bindings/pwm/pwm.txt | 7 ++++--- include/dt-bindings/pwm/pwm.h | 14 ++++++++++++++ 2 files changed, 18 insertions(+), 3 deletions(-) create mode 100644 include/dt-bindings/pwm/pwm.h