On 31.05.2018 18:56, Rob Herring wrote:
On Thu, May 31, 2018 at 10:31 AM, Stephen Boyd <sboyd@xxxxxxxxxx> wrote:
Quoting Rob Herring (2018-05-31 07:20:57)
On Thu, May 31, 2018 at 5:25 AM, Codrin Ciubotariu
<codrin.ciubotariu@xxxxxxxxxxxxx> wrote:
On 31.05.2018 03:58, Rob Herring wrote:
On Fri, May 25, 2018 at 03:34:22PM +0300, Codrin Ciubotariu wrote:
The I2S mux clock can be used to select the I2S input clock. The
available parents are the peripheral and the generated clocks.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>
---
.../devicetree/bindings/clock/at91-clock.txt | 34
++++++++++++++++++++++
1 file changed, 34 insertions(+)
diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt
b/Documentation/devicetree/bindings/clock/at91-clock.txt
index 51c259a..1c46b3c 100644
--- a/Documentation/devicetree/bindings/clock/at91-clock.txt
+++ b/Documentation/devicetree/bindings/clock/at91-clock.txt
@@ -90,6 +90,8 @@ Required properties:
"atmel,sama5d2-clk-audio-pll-pmc"
at91 audio pll output on AUDIOPLLCLK that feeds the PMC
and can be used by peripheral clock or generic clock
+ "atmel,sama5d2-clk-i2s-mux":
+ at91 I2S clock source selection
Is this boolean or takes some values. If latter, what are valid values?
This is the compatible string of the clock driver.
Ah, now I remember. AT91 uses fine grained clock nodes in DT. Is there
still a plan to fix this?
I'm also interested in a plan.
+ compatible = "atmel,sama5d2-clk-i2s-mux";
+ #address-cells = <1>;
+ #size-cells = <0>;
How do you address this block? My guess is you don't because it is just
part of some other block and you are just creating this node to
instantiate a driver. Just make the node for the actual h/w block a
clock provider and define the clock ids (0 and 1).
This block is not addressed, but its children are. The register we access in
this driver is not part of other block. It's a SFR register, accessed
through syscon and it has nothing to do with the I2S IP (see SAMA5D2 DS,
page 1256, fig. 44-1: I2SC Block Diagram) that is the consumer of this
clock. Adding a clock-id property in the I2S node would be just like v3 of
this series, with the difference that we use clock-id instead of alias id to
set the clock parent, which is not how you suggested back then.
I wasn't suggesting a clock-id property, but a clock specifier (i.e.
make #clock-cells 1).
But AT91 clocks are all a mess, so I don't know what to tell you.
If #clock-cells of 1 works then we should go with that. It's still weird
that we need random nodes to add more clks, but I guess that's how it's
going to be for each at91 clk driver until it changes to be one big
provider node.
Seems to me that clock additions could use a new binding and we start
with a new driver that handles these few clocks initially. But I
haven't looked whether both can coexist.
Mark already applied to broonie/sound.git the I2S bindings that have a
phandle to this clock. If I am to change #clock-cells to 1, I will have
to change the bindings to include the clock-id.
Which approach should I take now?
Thanks and best regards,
Codrin
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