Hi everyone,
I recently went mainline with our embedded device and so far I am happy that 
I've done it. Coming from a quite old kernel (4.1.15) there are some new 
features and changes I need to get my head around and one is bugging me for 
quite some time now.

We are using an RTC which depends on the m41t80 kernel driver. This RTC has a 
CLK-OUT feature which is per default to ON and 32kHz. We have another chip 
wired and depending to that clock signal.
On kernel version 4.1.15 there was no feature to enable/disable square wave 
output for this rtc driver, so it was always on per default.
In newer kernel versions is a change which is adding clock-provider feature to 
use and enable/disable that CLK-OUT feature.
Which results in the clock output signal being turned of as default option. Now 
I am totally lost on how to activate that feature in - I think the device tree?
I read through all documentation regarding the matter and tried adding clock 
attributes in the dts but with no luck so far. My entry is:

/* external real time clock */
i2c_rtc: rtc@68 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_rtc_int>;
compatible = "st,rv4162", "fixed-clock", "microcrystal,rv4162"; 
reg = <0x68>; 
interrupt-parent = <&gpio5>; 
interrupts = <1 IRQ_TYPE_LEVEL_LOW>; 
status = "okay"; 
#clock-cells = <1>; 
clock-frequency = <32678>; 
clock-output-names = "rtcosc"; 
};

Any help is appreciated!

Best regards,
Patrick

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