On 09/06/2016 07:42 PM, Prabhakar Kushwaha wrote: > >> -----Original Message----- >> From: york sun >> Sent: Tuesday, September 06, 2016 9:10 PM >> To: Prabhakar Kushwaha <prabhakar.kushw...@nxp.com>; u- >> b...@lists.denx.de >> Subject: Re: [PATCH] arch: ifc: update the IFC IP input clock >> >> On 09/06/2016 04:15 AM, Prabhakar Kushwaha wrote: >>> IFC IP clock is always a constant divisor of platform clock >>> pre-defined per SoC. Clock Control register (CCR) used in >>> current implementation governs IFC IP output clock. >>> >>> So update IFC IP clock to be defined as per predefined clock >>> divisor of platform clock. >>> >>> Signed-off-by: Prabhakar Kushwaha <prabhakar.kushw...@nxp.com> >>> --- >>> README | 3 +++ >>> arch/arm/cpu/armv7/ls102xa/clock.c | 10 ++-------- >>> arch/arm/cpu/armv8/fsl-layerscape/fsl_lsch2_speed.c | 10 ++-------- >>> arch/arm/cpu/armv8/fsl-layerscape/fsl_lsch3_speed.c | 10 ++-------- >>> arch/arm/include/asm/arch-fsl-layerscape/config.h | 3 +++ >>> arch/arm/include/asm/arch-ls102xa/config.h | 1 + >>> arch/powerpc/cpu/mpc85xx/speed.c | 10 ++-------- >>> arch/powerpc/include/asm/config_mpc85xx.h | 9 +++++++++ >>> 8 files changed, 24 insertions(+), 32 deletions(-) >> >> Prabkahar, >> >> Two concerns here >> >> 1, it is not only IFC for powerpc. Older SoCs have local bus. That's why >> the variable is named freq_localbus.. >> > > As per my understanding, Issue is valid for eLBC SoC also. > Just wanted to confirm from internal IP team before spinning patch to fix it. > >> 2, what's the reason for this change? Is it wrong to use ccr to >> calculate the clock? Or is it because recent Layerscape SoCs have >> platform PLL different from platform clock? If the latter, can we limit >> the fix to platform clock and not changing powerpc? >> > > CCR governs the IFC output clock. > This clock is used for synchronous NOR, NAND flashes. It is nowhere govern > IFC IP internal clock. > > It is true since conception of IFC. Unfortunately code written is wrong since > P1010. > It is confusing everyone. >
Are you saying the freq_localbus should be the internal clock, not output clock? As far as I can remember, this variable has always be used for output clock since 85xx. I am open to the idea to change to internal clock only if it makes sense. Browsing the code, I see this variable is used for information only, except for setting arch.lbc_clk. York York _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot