Hi Doug&Heiko, On 2016年06月01日 23:46, Heiko Stübner wrote:
Am Mittwoch, 1. Juni 2016, 08:24:48 schrieb Doug Anderson:Lin Huang,On Wed, Jun 1, 2016 at 2:35 AM, Lin Huang <h...@rock-chips.com> wrote:add ddrc clock setting, so we can do ddr frequency scaling on rk3399 platform in future. Signed-off-by: Lin Huang <h...@rock-chips.com> --- drivers/clk/rockchip/clk-rk3399.c | 16 ++++++++++++++++ include/dt-bindings/clock/rk3399-cru.h | 1 + 2 files changed, 17 insertions(+) diff --git a/drivers/clk/rockchip/clk-rk3399.c b/drivers/clk/rockchip/clk-rk3399.c index f1d8e44..749ea59 100644 --- a/drivers/clk/rockchip/clk-rk3399.c +++ b/drivers/clk/rockchip/clk-rk3399.c @@ -118,6 +118,10 @@ PNAME(mux_armclkb_p) = { "clk_core_b_lpll_src",> "clk_core_b_bpll_src", "clk_core_b_dpll_src", "clk_core_b_gpll_src" }; +PNAME(mux_ddrclk_p) = { "clk_ddrc_lpll_src", + "clk_ddrc_bpll_src", + "clk_ddrc_dpll_src", + "clk_ddrc_gpll_src" }; PNAME(mux_aclk_cci_p) = { "cpll_aclk_cci_src","gpll_aclk_cci_src","npll_aclk_cci_src", @@ -1377,6 +1381,18 @@ static struct rockchip_clk_branch rk3399_clk_branches[] __initdata = {> COMPOSITE_NOMUX(0, "clk_test", "clk_test_pre", CLK_IGNORE_UNUSED,RK3368_CLKSEL_CON(58), 0, 5, DFLAGS,RK3368_CLKGATE_CON(13), 11, GFLAGS), + + /* ddrc */ + GATE(0, "clk_ddrc_lpll_src", "lpll", CLK_IGNORE_UNUSED, + RK3399_CLKGATE_CON(3), 0, GFLAGS), + GATE(0, "clk_ddrc_bpll_src", "bpll", CLK_IGNORE_UNUSED, + RK3399_CLKGATE_CON(3), 1, GFLAGS), + GATE(0, "clk_ddrc_dpll_src", "dpll", CLK_IGNORE_UNUSED, + RK3399_CLKGATE_CON(3), 2, GFLAGS), + GATE(0, "clk_ddrc_gpll_src", "gpll", CLK_IGNORE_UNUSED, + RK3399_CLKGATE_CON(3), 3, GFLAGS), + COMPOSITE_DDRC(SCLK_DDRCLK, "clk_ddrc", mux_ddrclk_p, CLK_IGNORE_UNUSED, + RK3399_CLKSEL_CON(6), 4, 2, MFLAGS, 0, 3, DFLAGS),It seems slightly unfortunate that we need CLK_IGNORE_UNUSED on these. Only one of these will ever be used at once and it would be awfully nice if the others could get gated, right? ...presumably this is needed because we might not have an actual driver for DDR Freq and we definitely want to make sure that clk_ddrc is enabled in that case. I guess what we really want is something like CLK_ENABLE_HAND_OFF eventually, but until then I think you might get slightly better behavior by getting rid of all of these CLK_IGNORE_UNUSED and setting "clk_ddrc" as a critical clock, either using the table in this file or the new flag.My current feeling is that staying with the homegrown solution for critical clocks might be preferable until the clk-handoff mechanism lands as well, as our critical clocks fall into both categories and I'd like to not touch everything twice. The clock above should be controlled by the dcf, so falls into the handoff category (critical until a driver picks up the clock). Also mixing both new and old approach might get confusing. But I'm definitly open to counter-arguments :-)
I will remove CLK_IGNORE_UNUSED flag and set
"clk_ddrc" as critical clock in next version. Besides, i think we
should also
set "clk_ddrc_dpll_src" as critical clock, since we always use dpll
as ddr clock source,
and it should always on.
};static struct rockchip_clk_branch rk3399_clk_pmu_branches[] __initdata ={ diff --git a/include/dt-bindings/clock/rk3399-cru.h b/include/dt-bindings/clock/rk3399-cru.h index 50a44cf..8a0f0442 100644 --- a/include/dt-bindings/clock/rk3399-cru.h +++ b/include/dt-bindings/clock/rk3399-cru.h @@ -131,6 +131,7 @@ #define SCLK_DPHY_RX0_CFG 165 #define SCLK_RMII_SRC 166 #define SCLK_PCIEPHY_REF100M 167 +#define SCLK_DDRCLK 168Almost certainly you'll want to create a separate patch for the dt-bindings change since it will need to land in a different tree so it can be pulled into both Heiko's clock topic branch and dts64 topic branch.correct.
will fix next version, thanks.
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-- Lin Huang
