Hi Geert,

On 14 June 2017 at 17:42, Geert Uytterhoeven [off-list ref] wrote:

Hi Chunyan,

On Wed, Jun 14, 2017 at 11:21 AM, Chunyan Zhang
[off-list ref] wrote:

quoted

The value of property 'clock-cells' is not determined only by the number
of clock outputs in one clock node, it is determined by whether the clock
output in this node can be referenced directly without index. If the
output clock has to be referenced by a index, the clock-cell of this
clock node can't be defined 0.

Signed-off-by: Chunyan Zhang <redacted>
---
 Documentation/devicetree/bindings/clock/clock-bindings.txt | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt
index 2ec489e..e2b76b4 100644
--- a/Documentation/devicetree/bindings/clock/clock-bindings.txt
+++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt

@@ -18,6 +18,9 @@ Required properties:
                   with a single clock output and 1 for nodes with multiple
                   clock outputs.

+                  There's one exception, please see the description for
+                  clock-indices below.
+
 Optional properties:
 clock-output-names: Recommended to be a list of strings of clock output signal
                    names indexed by the first cell in the clock specifier.

@@ -48,6 +51,13 @@ clock-indices:          If the identifying number for the clocks in the node
                   is not linear from zero, then this allows the mapping of
                   identifiers into the clock-output-names array.

+                  This property not only servers for clocks with multiple

serves

Thanks, I will fix that.

quoted

+                  clock outputs, but also for clocks with a single clock
+                  output whose identifying number is not zero.

Why would you want a single clock and a non-zero identifying number?

Because of the probably weird hardwire design :)
There indeed some clocks like that on the platform I'm working on.

quoted

+                  So long as clock-indices is set, clock-cells cannot be
+                  set zero.

Gr{oetje,eeting}s,

                        Geert

Thanks for your review,
Chunyan

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds