From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joakim Tjernlund Date: Thu, 7 Sep 2017 06:55:22 +0000 Subject: [U-Boot] setup of PEX_GCLK_RATIO in E500 CPUs(P2010) missing ? In-Reply-To: References: <1504003621.4350.49.camel@infinera.com> <1504012881.32677.3.camel@infinera.com> <1504026376.32677.11.camel@infinera.com> <1504098321.32677.24.camel@infinera.com> <1504615525.27247.31.camel@infinera.com> Message-ID: <1504767319.27247.143.camel@infinera.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Thu, 2017-09-07 at 06:45 +0000, Mingkai Hu wrote: > > -----Original Message----- > > From: Mingkai Hu > > Sent: Wednesday, September 06, 2017 5:37 PM > > To: 'Joakim Tjernlund' ; Roy Zang > > ; York Sun > > Cc: u-boot at lists.denx.de > > Subject: RE: setup of PEX_GCLK_RATIO in E500 CPUs(P2010) missing ? > > > > > > > > > -----Original Message----- > > > From: Joakim Tjernlund [mailto:Joakim.Tjernlund at infinera.com] > > > Sent: Tuesday, September 05, 2017 8:45 PM > > > To: Mingkai Hu ; Roy Zang ; > > > > York > > > Sun > > > Cc: u-boot at lists.denx.de > > > Subject: Re: setup of PEX_GCLK_RATIO in E500 CPUs(P2010) missing ? > > > > > > On Wed, 2017-08-30 at 15:25 +0000, York Sun wrote: > > > > On 08/30/2017 06:05 AM, Joakim Tjernlund wrote: > > > > > On Tue, 2017-08-29 at 17:33 +0000, York Sun wrote: > > > > > > +Roy Zang to comment on PCIe clock source > > > > > > > > > > > > On 08/29/2017 10:06 AM, Joakim Tjernlund wrote: > > > > > > > On Tue, 2017-08-29 at 15:43 +0000, York Sun wrote: > > > > > > > > On 08/29/2017 06:21 AM, Joakim Tjernlund wrote: > > > > > > > > > On Tue, 2017-08-29 at 12:47 +0200, Joakim Tjernlund wrote: > > > > > > > > > > As we are looking at PCI stuff ATM I would like to ask > > > > > > > > > > about PEX_GCLK_RATIO in E500 CPUs. I cannot find this is > > > > > > > > > > setup at all for E500 but I THINK this is required. > > > > > > > > > > > > > > > > > > > > In 83xx one do: > > > > > > > > > > get_clocks(); > > > > > > > > > > /* Configure the PCIE controller core clock ratio */ > > > > > > > > > > out_le32(hose_cfg_base + PEX_GCLK_RATIO, > > > > > > > > > > > > > > > > > > A bit strange with out_le32 instead of out_be32 ? > > > > > > > > > > > > > > > > > > > (((bus ? gd->arch.pciexp2_clk : gd->arch.pciexp1_clk) / > > > > > > > > > > 1000000) * 16) / 333); udelay(1000000); > > > > > > > > > > > > > > > > > > > > Any clues? > > > > > > > > > > > > > > > > > > > > Jocke > > > > > > > > > > > > > > > > > > Seems like only 83xx is setting this parameter. > > > > > > > > > > > > > > > > > > Anyhow, I put together this patch: > > > > > > > > > > > > > > > > > > --- a/drivers/pci/fsl_pci_init.c > > > > > > > > > +++ b/drivers/pci/fsl_pci_init.c > > > > > > > > > @@ -322,6 +322,10 @@ void fsl_pci_init(struct > > > > > > > > > pci_controller *hose, struct fsl_pci_info *pci_info) > > > > > > > > > > > > > > > > > > pci_setup_indirect(hose, cfg_addr, cfg_data); > > > > > > > > > > > > > > > > > > + /* Configure the PCIE controller core clock ratio */ > > > > > > > > > + pci_hose_write_config_dword(hose, dev, 0x440, (gd- > > > > > > > > bus_clk / 333333333) * 16); > > > > > > > > > + /* udelay(1000000) needed here ?*/ > > > > > > > > > + > > > > > > > > > block_rev = in_be32(&pci->block_rev1); > > > > > > > > > if (PEX_IP_BLK_REV_2_2 <= block_rev) { > > > > > > > > > pi = &pci->pit[2]; /* 0xDC0 */ > > > > > > > > > > > > > > > > > > Any chance this will work for all supported FSL PCIe controllers? > > > > > > > > > > > > > > > > > > > > > > > > > Jocke, > > > > > > > > > > > > > > > > You don't need to program this register if the actual PCIe > > > > > > > > clock is the same as default. Since SerDes reference clock > > > > > > > > has to be 100MHz for PCIe protocol, my guess is the PCIe > > > > > > > > clock is always correct. The bus_clk you are referring is > > > > > > > > not the PCIe clock. Again, I am not a PCIe expert, I could > > > > > > > > be wrong. Since PCIe (SerDes) has been working on multiple > > > > > > > > platforms, I guess the > > > > > > clock is correct. > > > > > > > > > > > > > > I don't think so. Here is what T1042 says about this: > > > > > > > > > > > > > > The PCI Express controller clock frequency is one-half the > > > > > > > platform > > > > > > clock frequency. > > > > > > > > > > > > > > The PCI Express controller core clock ratio register is used > > > > > > > to program the ratio of the actual PCI Express controller > > > > > > > clock frequency to the default controller core frequency ( 333 MHz ). > > > > > > > This is required only when a PCI Express controller clock > > > > > > > frequency > > > > > > other than the default 333 MHz has to be used. > > > > > > > As an example of programming PEX_GCLK_RATIO, consider the case > > > > > > > where the actual PCI Express controller clock is 250 MHz, the > > > > > > > ratio of the actual clock to the default clock ( 333 MHz) is > > > > > > > 3:4. that is, the default core clock has to be multiplied by > > > > > > > the ratio (3/4, which is equivalent to 12/16). So the register > > > > > > > has to be > > > > > > programmed with the decimal numerator value 12 or 0x0000_000C. > > > > > > > > > > > > > > Our CCB is 250 MHz so this should be set to 0xc. > > > > > > > > > > > > > > I found this on Google too: > > > > > > > The PEX controller hardware requires for timing tuning in > > > > > > > order to operate properly at given CCB/2 clock frequency. > > > > > > > PEX_GCLK_RATIO register controls this tuning with 333MHz/16 > > > > > > > granularities. So for given CCB frequency Fccb [MHz] we must > > > > > > > write to > > > > > > PEX_GCLK_RATIO nearest integer of ((Fccb/2)/(333/16)). So for Fccb=375 > > > we have to write 18. > > > > > > > > > > > > Jocke, > > > > > > > > > > > > Basically I agree with you, if the clock is different from > > > > > > default, you need to set the ratio. T104x indeed uses 1/2 > > > > > > platform clock as PCIe clock. I am not sure if P2010 uses the > > > > > > same way. Let me add Roy to this thread. > > > > > > > > > > > > Roy, how do we get PCIe clock for P1/T1 (and other mpc85xx) SoCs? > > > > > > Don't we need to set PEX_GCLK_RATIO register? It is not even in > > > > > > the > > > > > > header file. > > > > > > > > > > Patch was off, this works: > > > > > diff --git a/drivers/pci/fsl_pci_init.c > > > > > b/drivers/pci/fsl_pci_init.c index 52792dcd59..e7f2499784 100644 > > > > > --- a/drivers/pci/fsl_pci_init.c > > > > > +++ b/drivers/pci/fsl_pci_init.c > > > > > @@ -322,6 +322,11 @@ void fsl_pci_init(struct pci_controller > > > > > *hose, struct fsl_pci_info *pci_info) > > > > > > > > > > pci_setup_indirect(hose, cfg_addr, cfg_data); > > > > > > > > > > + /* Configure the PCIE controller core clock ratio */ > > > > > + pci_hose_write_config_dword(hose, dev, 0x440, > > > > > > > > pci_hose_write_config_dword() writes to config space, doesn't it? > > > > 0x440 is not in config space. > > > > > > > > > + ((gd->bus_clk / 1000000) * 16/2) / 333); > > > > > + /* udelay(1000000) needed here ?*/ > > > > > > > > Let us not to add delay if we don't know yet. > > > > > > > > > + > > > > > block_rev = in_be32(&pci->block_rev1); > > > > > if (PEX_IP_BLK_REV_2_2 <= block_rev) { > > > > > pi = &pci->pit[2]; /* 0xDC0 */ > > > > > > > > > > > > > > > Any news on this ? > > > > > I know both T1042 and P2010 has the same setting/formula, a good > > > > > start :) > > > > > > > > +Mingkai to comment on PCIe clock > > > > > > > > York > > > > This is the clock to PCIe controller which is not different from the clock to > > PCIe SerDes lane. > > My understanding is that it should be configured according to the platform > > frequency. > > But there is no specific and consistent description for all the platforms. I am > > checking with the design team to see if there is hardware fixed clock to PCIe > > controller for the platforms which don't have clear description. Will keep you > > all updated. > > > > This ratio will be used by GPEX only to calculate the actual timer values to be used for Ack Latency and > Replay timeout values and the FC update timer value under traffic condition. It's applicable for all PowerPC > controllers except T4 and T2 family, so would you please help to update the patch to set the register > according to platform clock (or platform/2, need to check chip RM) excluding T4/T2 platform? I think NXP is in a better position to adjust the patch w.r.t actual PCIe clock. I just want to known, for now, what PCIe clock is for T1042 and P2010, CCB or CCB/2, so we can set the correct value and continue with our trouble shooting. T1040RM actually has this writing in 28.11.19: The PCI Express controller clock frequency is one-half the platform clock frequency. .... That indicates the PCIe clock is CCB/2. P2010 does not have that text. Please advice. Jocke