On Thu, Mar 23, 2017 at 07:17:03AM +0800, Icenowy Zheng wrote: > > > 23.03.2017, 04:09, "Maxime Ripard" <maxime.ripard@xxxxxxxxxxxxxxxxxx>: > > On Wed, Mar 22, 2017 at 02:22:22AM +0800, Icenowy Zheng wrote: > >> 21.03.2017, 15:41, "Maxime Ripard" <maxime.ripard@xxxxxxxxxxxxxxxxxx>: > >> > On Thu, Mar 16, 2017 at 01:28:04AM +0800, Icenowy Zheng wrote: > >> >> Many Allwinner SoCs after A31 have a CCU in PRCM block. > >> >> > >> >> Give the ones on H3 and A64 compatible strings. > >> >> > >> >> Signed-off-by: Icenowy Zheng <icenowy@xxxxxxxx> > >> >> --- > >> >> Changes in v2: > >> >> - Add iosc for R_CCU's on H3/A64. (A31, A23 and A33 seem to have different > >> >> clock for mux 3 of ar100 clk. Investgations are needed for them.) > >> >> > >> >> Documentation/devicetree/bindings/clock/sunxi-ccu.txt | 18 +++++++++++++++++- > >> >> 1 file changed, 17 insertions(+), 1 deletion(-) > >> >> > >> >> diff --git a/Documentation/devicetree/bindings/clock/sunxi-ccu.txt b/Documentation/devicetree/bindings/clock/sunxi-ccu.txt > >> >> index 68512aa398a9..4a4addff595d 100644 > >> >> --- a/Documentation/devicetree/bindings/clock/sunxi-ccu.txt > >> >> +++ b/Documentation/devicetree/bindings/clock/sunxi-ccu.txt > >> >> @@ -7,9 +7,11 @@ Required properties : > >> >> - "allwinner,sun8i-a23-ccu" > >> >> - "allwinner,sun8i-a33-ccu" > >> >> - "allwinner,sun8i-h3-ccu" > >> >> + - "allwinner,sun8i-h3-r-ccu" > >> >> - "allwinner,sun8i-v3s-ccu" > >> >> - "allwinner,sun9i-a80-ccu" > >> >> - "allwinner,sun50i-a64-ccu" > >> >> + - "allwinner,sun50i-a64-r-ccu" > >> >> - "allwinner,sun50i-h5-ccu" > >> >> > >> >> - reg: Must contain the registers base address and length > >> >> @@ -20,7 +22,11 @@ Required properties : > >> >> - #clock-cells : must contain 1 > >> >> - #reset-cells : must contain 1 > >> >> > >> >> -Example: > >> >> +For the PRCM CCUs on H3/A64, one more clock is needed: > >> >> +- "iosc": another frequency oscillator used for CPUS (usually at 32000Hz, > >> >> + not the same with losc) > >> > > >> > This is called the internal oscillator in the datasheet, it would > >> > probably make more sense to call it that way in the documentation too. > >> > > >> > This oscillator seems to be clocked at 16MHz, so we should represent > >> > it as such. > >> > > >> > And I'm wondering, are you *sure* that it's fed directly from the > >> > internal oscillator, or goes through the registers in the RTC, with > >> > the 32 divider and 16 prescaler by default that makes it at roughly > >> > the same rate (31.25kHz). > >> > >> In fact I know nothing about it -- I only represented the code in BSP > >> clock driver. > >> > >> The mux value 3 varies from SoC to SoC. For A64/H5 it's 32000, > >> for A33 it's 667000 (seems to be directly the internal OSC, as the > >> user manual says the internal OSC is 600~700kHz; but it's named > >> cpuosc rather than iosc in A33 BSP clock driver); for A80 it's even > >> PLL_AUDIO. > > > > Where are you getting those info from? > > > > As far as I know, the A33 PRCM takes the hosc, losc, pll6 and CPU > > (internal) oscillator: > > https://github.com/allwinner-zh/linux-3.4-sunxi/blob/master/drivers/clk/sunxi/clk-sun8iw5.c#L508 > > > > The H3 takes the hosc and losc: > > https://github.com/allwinner-zh/linux-3.4-sunxi/blob/master/drivers/clk/sunxi/clk-sun8iw7.c#L379 > > > > The A80 takes the hosc and losc: > > https://github.com/allwinner-zh/linux-3.4-sunxi/blob/master/drivers/clk/sunxi/clk-sun9iw1.c#L281 > > > > The A64 takes the hosc, losc, pll-periph0 and the iosc, which indeed > > seems to be fed from the internal oscillator with the divider in the > > RTC: > > https://github.com/longsleep/linux-pine64/blob/lichee-dev-v3.10.65-bsp2.0/arch/arm64/boot/dts/sun50iw1p1-clk.dtsi#L19 > > https://github.com/longsleep/linux-pine64/blob/lichee-dev-v3.10.65-bsp2.0/drivers/clk/sunxi/clk-sun50iw1.c#L603 > > But then in sunxi_init_clocks function, the iosc clock is initialized > as a fixed clock with 32000Hz. > > The clock node in BSP device tree have a compatible of > allwinner,fixed-clock, but not fixed-clock, which makes it not able > to be really probed. That clock is registered: https://github.com/longsleep/linux-pine64/blob/lichee-dev-v3.10.65-bsp2.0/drivers/clk/sunxi/clk-sun50iw1.c#L1193 Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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