On 27/04/16 09:04, H. Nikolaus Schaller wrote:
Am 26.04.2016 um 19:27 schrieb Tony Lindgren <tony@xxxxxxxxxxx>:
Tero,
* H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> [160418 11:23]:
OMAP5 has a register to control if the ckobuffer is enabled
and defines the polarity. ckobuffer is required to drive a twl6040
with the system clock. Hence, add the pinctrl,single to the
OMAP5 SoC description so that omap5-board-common can
set up the ckobuffer as required.
Is this really a mux or should it be a mux clock?
It is a pinmux setting for the clock out buffer to choose what signal
(and polarity) is presented on the fref_xtal_clk pad.
The register is part of the CTRL_MODULE_WKUP.
The clock signal is the xtal master clock of the whole SoC.
Although there is a bit to choose an alternate clock, there is no
alternate in the OMAP5 silicon.
Therefore I would say it is about padconf and not clock or clock mux
related.
It just happens to be a clock signal which can be routed to this
pad.
The two could very well be implemented as clock nodes, a mux and a gate.
This would describe the hardware functionality better imo, if the
assumptions made here are correct. Implementing the control as pinctrl
hacks looks rather weird to me.
I could not find any documentation related to the ckobuffer usage
though, maybe Peter can provide some insight? I think you spent some
considerable time bringing up twl6040 a few years back...
-Tero
BR,
Nikolaus
Regards,
Tony
Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
---
arch/arm/boot/dts/omap5.dtsi | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/arm/boot/dts/omap5.dtsi b/arch/arm/boot/dts/omap5.dtsi
index 120b6b8..1d9050f 100644
--- a/arch/arm/boot/dts/omap5.dtsi
+++ b/arch/arm/boot/dts/omap5.dtsi
@@ -277,6 +277,16 @@
pinctrl-single,register-width = <16>;
pinctrl-single,function-mask = <0x7fff>;
};
+
+ omap5_control_ckobuffer: pinmux@cdb4 {
+ compatible = "ti,omap5-padconf",
+ "pinctrl-single";
+ reg = <0xcdb4 4>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ pinctrl-single,register-width = <32>;
+ pinctrl-single,function-mask = <0xf0000000>;
+ };
};
ocmcram: ocmcram@40300000 {
--
2.7.3
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