On Wed, Jun 15, 2016 at 09:29:55AM +0200, Boris Brezillon wrote:

On Tue, 14 Jun 2016 16:47:37 -0500
Rob Herring [off-list ref] wrote:

quoted

On Sat, Jun 11, 2016 at 12:03:05AM +0200, Alexandre Belloni wrote:

quoted

The current binding for the TCB is not flexible enough for some use cases
and prevents proper utilization of all the channels.

Cc: Daniel Lezcano <redacted>
Cc: Thierry Reding <redacted>
Cc: linux-pwm at vger.kernel.org
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree at vger.kernel.org
Signed-off-by: Alexandre Belloni <redacted>
---
 .../devicetree/bindings/arm/atmel-at91.txt         | 32 -----------
 .../devicetree/bindings/mfd/atmel-tcb.txt          | 62 ++++++++++++++++++++++
 .../devicetree/bindings/pwm/atmel-tcb-pwm.txt      | 12 +++--
 3 files changed, 69 insertions(+), 37 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mfd/atmel-tcb.txt  

[...]

quoted

quoted

diff --git a/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt b/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt
index 8031148bcf85..ab8fbd5ba184 100644
--- a/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/atmel-tcb-pwm.txt

@@ -2,15 +2,17 @@ Atmel TCB PWM controller
 
 Required properties:
 - compatible: should be "atmel,tcb-pwm"
+- reg: tcb channel to use. Each channel can export 2 PWMs  

Is there a difference in channels? If not, then this compatible should 
go.

This one I don't understand.
The TCB (Timer Counter Block) is an MFD containing 3 Timer Counter
devices. Each of these devices (also called channels) can be assigned a
specific mode:
- timer mode (free-running of programmable)
- waveform generator mode (IOW, a PWM)
- capture mode (an IIO device, but we don't have any driver for that
  right now)

So each sub-device of the TCB is represented as a sub-node with its own
compatible. Is there a problem with that?

Missed this in my first reply. I guess for purposes of referencing pwm 
from other nodes this is okay.

Rob