> -----Original Message----- > From: york sun > Sent: Thursday, September 08, 2016 7:33 AM > To: Prabhakar Kushwaha <prabhakar.kushw...@nxp.com>; u- > b...@lists.denx.de > Subject: Re: [PATCH] arch: ifc: update the IFC IP input clock > > On 09/07/2016 06:30 PM, Prabhakar Kushwaha wrote: > > > >> -----Original Message----- > >> From: york sun > >> Sent: Wednesday, September 07, 2016 9:17 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 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. > >> > > > > Everyone believe it to be IFC internal clock not the output clock. > > Not everyone. > > > As I always used to get query from customers about wrong IFC speed. > > > > So better to print IP clock to avoid any confusion. > > IFC output clock will be printed when it is actually being used during > synchronous NOR, syn NAND. > > I am not against changing it to internal clock. But what are you going > to print on the console? I think it is confusing to say IFC or local bus > internal clock speed. Please also check how this clock is used and make > sure arch.lbc_clk is still correct, after passing to Linux. > arch.lbc_clk is only being used for eLBC for device tree fixup. And I checked the Linux eLBC driver. Looks like it is not using used.
No device tree fixup is being done for IFC. --prabhakar _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
