On 22/05/14 14:01, Tomasz Figa wrote: >>>> >>> [ ... ] >>>> >>> >>>>> >>>> + clkout->clk_table[0] = clk_register_composite(NULL, "clkout", >>>>> >>>> + parent_names, parent_count, &clkout->mux.hw, >>>>> >>>> + &clk_mux_ops, NULL, NULL, &clkout->gate.hw, >>>>> >>>> + &clk_gate_ops, CLK_SET_RATE_PARENT >>>>> >>>> + | CLK_SET_RATE_NO_REPARENT); >>>> >>> >>>> >>> Would you please remove CLK_SET_RATE_NO_REPARENT flag from here? Let me >>>> >>> know if you have reservations against this. >>> >> >>> >> The problem with clock reparenting is that there are certain parent >>> >> clocks of CLKOUT, rate of which changes at runtime, e.g. clocks derived >>> >> from APLL or bus clocks, which can be reconfigured by cpufreq or devfreq. >>> >> >> > >> > +CC: Sylwester Nawrocki >> > >> > Okay. But in cases where there is only 1 valid parent clock provided >> > through DT (at the moment for Exynos5250/Exynos5420), would it be safe >> > to set that clock as the parent of CLKOUT? > > This is not something to rely on. I have simply omitted remaining CLKOUT > parents on Exynos 5 SoCs, as I don't have any board with them on which I > could test this. Eventually they will be added. > >> > Otherwise, this clock is >> > not usable ATM. > > On many boards it is already configured properly by the bootloader. > Although I don't see any reason why you couldn't reparent it in > (board-specific) sound card driver right now. This would require passing the parent's clock specifier in 'clocks' property of the sound card device node, which I assume is not something we're generally expected to do in mainline. Although some drivers happen to be doing it already I think that's a bad example. It sounds like an abuse of the current clock bindings. -- Regards, Sylwester -- 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
