On 22 May 2014 17:31, Tomasz Figa <t.figa@xxxxxxxxxxx> wrote: > On 22.05.2014 13:44, Tushar Behera wrote: >> On 22 May 2014 16:04, Tomasz Figa <t.figa@xxxxxxxxxxx> wrote: >>> On 22.05.2014 07:13, Tushar Behera wrote: >>>> On 05/20/2014 10:13 PM, Tomasz Figa wrote: >>>>> This patch introduces a driver that handles configuration of CLKOUT pin >>>>> of Exynos SoCs that can be used to output certain clocks from inside of >>>>> the SoC to a dedicated output pin. >>>>> >>>>> Signed-off-by: Tomasz Figa <t.figa@xxxxxxxxxxx> >>>>> --- >>>>> .../devicetree/bindings/arm/samsung/pmu.txt | 30 ++++ >>>>> drivers/clk/samsung/Makefile | 1 + >>>>> drivers/clk/samsung/clk-exynos-clkout.c | 153 +++++++++++++++++++++ >>>>> 3 files changed, 184 insertions(+) >>>>> create mode 100644 drivers/clk/samsung/clk-exynos-clkout.c >>>>> >>>> >>>> [ ... ] >>>> >>>>> + 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. > Mark, Is this (clock reparenting in sound card driver) an acceptable solution for you? -- Tushar Behera -- 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
