[alsa-devel] [PATCH 1/4] dt-bindings: Document the dmas and dma-names properties for bcm2835-analog-audio

[Michael Zoran]

Add documentation for the DMA properties required when using the
PWM controller of the bcm2835 for analog audio output.

Signed-off-by: Michael Zoran <mzoran at crowfest.net>
---
 Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt b/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt
index cf573e85b11d..08fc06fc083a 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-bcm2835.txt
@@ -1,14 +1,21 @@
 BCM2835 PWM controller (Raspberry Pi controller)
 
 Required properties:
-- compatible: should be "brcm,bcm2835-pwm"
+- compatible: should be "brcm,bcm2835-pwm" or "brcm,bcm2835-analog-audio"
 - reg: physical base address and length of the controller's registers
 - clocks: This clock defines the base clock frequency of the PWM hardware
   system, the period and the duty_cycle of the PWM signal is a multiple of
   the base period.
+
+Required properties(PWM Output):
 - #pwm-cells: Should be 2. See pwm.txt in this directory for a description of
   the cells format.
 
+Required properties(Audio Output):
+- dmas: Should contain one entry pointing to the DMA channel used to
+	transfer audio data
+- dma-names:   Should contain "tx"
+
 Examples:
 
 pwm at 2020c000 {
-- 
2.11.0