From mboxrd@z Thu Jan 1 00:00:00 1970 From: icenowy@aosc.xyz (Icenowy Zheng) Date: Thu, 23 Mar 2017 07:17:03 +0800 Subject: [PATCH v2 1/5] dt-bindings: update device tree binding for Allwinner PRCM CCUs In-Reply-To: <20170322200923.tcr7yqnfqj2zk2v7@lukather> References: <20170315172808.64011-1-icenowy@aosc.xyz> <20170315172808.64011-2-icenowy@aosc.xyz> <20170321074117.vdfjynauuuv6fivp@lukather> <115431490120542@web34g.yandex.ru> <20170322200923.tcr7yqnfqj2zk2v7@lukather> Message-ID: <997781490224623@web30o.yandex.ru> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 23.03.2017, 04:09, "Maxime Ripard" : > On Wed, Mar 22, 2017 at 02:22:22AM +0800, Icenowy Zheng wrote: >> ?21.03.2017, 15:41, "Maxime Ripard" : >> ?> 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 >> ?>> ?--- >> ?>> ?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. > > Maxime > > -- > Maxime Ripard, Free Electrons > Embedded Linux and Kernel engineering > http://free-electrons.com