Re: [PATCH v2 04/18] clocksource: Add ARM System timer driver

2015-03-09 16:50 GMT+01:00 Linus Walleij [off-list ref]:

On Fri, Feb 20, 2015 at 7:01 PM, Maxime Coquelin
[off-list ref] wrote:

quoted

This patch adds clocksource support for ARMv7-M's System timer,
also known as SysTick.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>

(...)

quoted

+       /* If no clock found, try to get clock-frequency property */
+       if (!rate) {
+               ret = of_property_read_u32(np, "clock-frequency", &rate);
+               if (ret)
+                       goto out_unmap;
+       }

If this driver is only used for this one system, and if on this one system
the clk subsystem will provide the clock rate, then there is no need
to include this hackaround property.

Alternatively there is no point including reading the frequency from
the clk subsystem for this one system.

So which one is it?

In the first version, the "clock-frequency" property handling was not here.
Rob Herring advised me to add its support, as it could be used by
simple systems not selecting CCF.

So, I don't have the name of a system where it could be useful, but I
think Rob's request make sense.

Note that I tested using the clock-frequency property before sending.

Best regards,
Maxime

Yours,
Linus Walleij