Hello Arnd, On Wed, Mar 11, 2015 at 10:53 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Wednesday 11 March 2015 02:00:59 Javier Martinez Canillas wrote: >> >> What do you mean by parsing here? IIUC there isn't a clock driver for >> these clocks and are setup directly in the >> drivers/net/wireless/ti/wl12xx/main.c driver. >> >> So you can't make the WLAN chip dev node a consumer of these clocks by >> adding a phandle to a clock provider and clock specifiers since there >> isn't a provider to be referenced in the DT. Or did I misunderstand? > > As I understand it, the clock signal is provided by an external oscillator, According to [0], it seems the chip can be connected to both external oscillators or internal clocks provided by the chip itself. > which we can easily model in DT, and then you call clk_get_rate on that. > Right, my point wast that this can be done only if the external oscillator have a proper clock driver / provider which I don't think is the case here. Most of this stuff predates the common clock framework. Or at least Luciano Coelho had a patch on his series to make the wilink driver a clock provider itself by registering the refclock and tcxoclock clocks [0]. Luciano also had patches for: * Adding the clock provider dev node in the DTS [1] * Have a table to map the clock rate with the FW configuration values [2] * Getting the clock from DT and the rate as you said to configure the firmware accordingly [3] I think that patch [0] should not be needed since for external clocks, the IP providing the clocks should have its own clock driver and for internal clocks, a property should be used instead as you said. > If there is no external clock provider for this chip and the clocks > are provided by the device itself, then all we need is a clock-frequency > property in the device node. > Agreed, IIUC Luciano wanted to expose the internal clocks by registering in the common clock framework but if those clocks are not really accessible from outside the wlan chip, then I also think that a device node property should be used instead. > Arnd > -- Best regards, Javier [0]: https://lists.ozlabs.org/pipermail/devicetree-discuss/2013-July/037139.html [1]: http://lists.infradead.org/pipermail/linux-arm-kernel/2013-July/187794.html [2]: http://lists.infradead.org/pipermail/linux-arm-kernel/2013-July/181594.html [3]: http://lists.infradead.org/pipermail/linux-arm-kernel/2013-July/181591.html -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
