pwm: vt8500: Add polarity support

Add support to set polarity on PWM devices, allowing for inverted
duty cycles.

Also update the binding document to #pwm-cells = <3> to allow
passing the flags from devicetree.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
This commit is contained in:
Tony Prisk
2013-01-03 08:44:16 +13:00
committed by Thierry Reding
parent 8ab432caa4
commit 3ccb1c1702
2 changed files with 29 additions and 3 deletions

View File

@@ -3,14 +3,17 @@ VIA/Wondermedia VT8500/WM8xxx series SoC PWM controller
Required properties:
- compatible: should be "via,vt8500-pwm"
- reg: physical base address and length of the controller's registers
- #pwm-cells: should be 2. The first cell specifies the per-chip index
of the PWM to use and the second cell is the period in nanoseconds.
- #pwm-cells: Should be 3. Number of cells being used to specify PWM property.
First cell specifies the per-chip index of the PWM to use, the second
cell is the period in nanoseconds and bit 0 in the third cell is used to
encode the polarity of PWM output. Set bit 0 of the third in PWM specifier
to 1 for inverse polarity & set to 0 for normal polarity.
- clocks: phandle to the PWM source clock
Example:
pwm1: pwm@d8220000 {
#pwm-cells = <2>;
#pwm-cells = <3>;
compatible = "via,vt8500-pwm";
reg = <0xd8220000 0x1000>;
clocks = <&clkpwm>;