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? Otherwise, this clock is not usable ATM. >> >> With RFC patches, I am able to do a clk_set_rate() on this clock to >> get a 24MHz output to the codec clock. With this flag set, I again have >> to rely on the default value set to this register in bootloader. >> > > This problem should be handled by initializing clocks from DT. I'm not > sure why it hasn't been implemented yet... I would be happy to get it done that way. I can see a patch from Sylwester regarding this, but there hasn't been a conclusion as of yet. https://lkml.org/lkml/2014/4/9/173 Thanks, -- 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
