| Message ID | 20230418122403.3178462-13-yoshihiro.shimoda.uh@renesas.com |
|---|---|
| State | New |
| Headers | show |
| Series | PCI: rcar-gen4: Add R-Car Gen4 PCIe support | expand |
On Tue, Apr 18, 2023 at 09:23:53PM +0900, Yoshihiro Shimoda wrote: > Add dw_pcie_link_set_max_cap_width() to set PCI_EXP_LNKCAP_MLW. > In accordance with the DW PCIe RC/EP HW manuals [1,2,3,...] aside with > the PORT_LINK_CTRL_OFF.LINK_CAPABLE and GEN2_CTRL_OFF.NUM_OF_LANES[8:0] > field there is another one which needs to be update. It's s/update/updated > LINK_CAPABILITIES_REG.PCIE_CAP_MAX_LINK_WIDTH. If it isn't done at > the very least the maximum link-width capability CSR won't expose > the actual maximum capability. > > [1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > Version 4.60a, March 2015, p.1032 > [2] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > Version 4.70a, March 2016, p.1065 > [3] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > Version 4.90a, March 2016, p.1057 > ... > [X] DesignWare Cores PCI Express Controller Databook - DWC PCIe Endpoint, > Version 5.40a, March 2019, p.1396 > [X+1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > Version 5.40a, March 2019, p.1266 > > The commit description is suggested by Serge Semin. > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> > --- > drivers/pci/controller/dwc/pcie-designware.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c > index c76fa78c6468..2413cd39310c 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.c > +++ b/drivers/pci/controller/dwc/pcie-designware.c > @@ -737,6 +737,21 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen) > dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, cap | link_speed); > } > > +void dw_pcie_link_set_max_cap_width(struct dw_pcie *pci, int num_lanes) static? Or if you want other drivers to make use of it, then define it as a common PCI function (not dwc specific) and also update one potential user (pci-mvebu.c). I think you need to do the later. - Mani > +{ > + u32 val; > + u8 cap; > + > + if (!num_lanes) > + return; > + > + cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > + val = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP); > + val &= ~PCI_EXP_LNKCAP_MLW; > + val |= num_lanes << PCI_EXP_LNKSTA_NLW_SHIFT; > + dw_pcie_writel_dbi(pci, cap + PCI_EXP_LNKCAP, val); > +} > + > static void dw_pcie_link_set_max_width(struct dw_pcie *pci, u32 num_lanes) > { > u32 val; > @@ -1073,6 +1088,7 @@ void dw_pcie_setup(struct dw_pcie *pci) > dw_pcie_writel_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS, val); > } > > + dw_pcie_link_set_max_cap_width(pci, pci->num_lanes); > dw_pcie_link_set_max_width(pci, pci->num_lanes); > dw_pcie_link_set_max_link_width(pci, pci->num_lanes); > } > -- > 2.25.1 >
Hi Manivannan, > From: Manivannan Sadhasivam, Sent: Saturday, April 22, 2023 10:49 PM > > On Tue, Apr 18, 2023 at 09:23:53PM +0900, Yoshihiro Shimoda wrote: > > Add dw_pcie_link_set_max_cap_width() to set PCI_EXP_LNKCAP_MLW. > > In accordance with the DW PCIe RC/EP HW manuals [1,2,3,...] aside with > > the PORT_LINK_CTRL_OFF.LINK_CAPABLE and GEN2_CTRL_OFF.NUM_OF_LANES[8:0] > > field there is another one which needs to be update. It's > > s/update/updated Oops. I'll fix it. > > LINK_CAPABILITIES_REG.PCIE_CAP_MAX_LINK_WIDTH. If it isn't done at > > the very least the maximum link-width capability CSR won't expose > > the actual maximum capability. > > > > [1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > > Version 4.60a, March 2015, p.1032 > > [2] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > > Version 4.70a, March 2016, p.1065 > > [3] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > > Version 4.90a, March 2016, p.1057 > > ... > > [X] DesignWare Cores PCI Express Controller Databook - DWC PCIe Endpoint, > > Version 5.40a, March 2019, p.1396 > > [X+1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > > Version 5.40a, March 2019, p.1266 > > > > The commit description is suggested by Serge Semin. > > > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> > > --- > > drivers/pci/controller/dwc/pcie-designware.c | 16 ++++++++++++++++ > > 1 file changed, 16 insertions(+) > > > > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c > > index c76fa78c6468..2413cd39310c 100644 > > --- a/drivers/pci/controller/dwc/pcie-designware.c > > +++ b/drivers/pci/controller/dwc/pcie-designware.c > > @@ -737,6 +737,21 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen) > > dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, cap | link_speed); > > } > > > > +void dw_pcie_link_set_max_cap_width(struct dw_pcie *pci, int num_lanes) > > static? Or if you want other drivers to make use of it, then define it as a > common PCI function (not dwc specific) and also update one potential user > (pci-mvebu.c). I think you need to do the later. Oops. This should be static. But, this function cannot be for other uesrs because this function needs to use dw_pcie_{read,write}l which are for dwc controllers. Best regards, Yoshihiro Shimoda > - Mani > > > +{ > > + u32 val; > > + u8 cap; > > + > > + if (!num_lanes) > > + return; > > + > > + cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > > + val = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP); > > + val &= ~PCI_EXP_LNKCAP_MLW; > > + val |= num_lanes << PCI_EXP_LNKSTA_NLW_SHIFT; > > + dw_pcie_writel_dbi(pci, cap + PCI_EXP_LNKCAP, val); > > +} > > + > > static void dw_pcie_link_set_max_width(struct dw_pcie *pci, u32 num_lanes) > > { > > u32 val; > > @@ -1073,6 +1088,7 @@ void dw_pcie_setup(struct dw_pcie *pci) > > dw_pcie_writel_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS, val); > > } > > > > + dw_pcie_link_set_max_cap_width(pci, pci->num_lanes); > > dw_pcie_link_set_max_width(pci, pci->num_lanes); > > dw_pcie_link_set_max_link_width(pci, pci->num_lanes); > > } > > -- > > 2.25.1 > > > > -- > மணிவண்ணன் சதாசிவம்
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index c76fa78c6468..2413cd39310c 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -737,6 +737,21 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen) dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, cap | link_speed); } +void dw_pcie_link_set_max_cap_width(struct dw_pcie *pci, int num_lanes) +{ + u32 val; + u8 cap; + + if (!num_lanes) + return; + + cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + val = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP); + val &= ~PCI_EXP_LNKCAP_MLW; + val |= num_lanes << PCI_EXP_LNKSTA_NLW_SHIFT; + dw_pcie_writel_dbi(pci, cap + PCI_EXP_LNKCAP, val); +} + static void dw_pcie_link_set_max_width(struct dw_pcie *pci, u32 num_lanes) { u32 val; @@ -1073,6 +1088,7 @@ void dw_pcie_setup(struct dw_pcie *pci) dw_pcie_writel_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS, val); } + dw_pcie_link_set_max_cap_width(pci, pci->num_lanes); dw_pcie_link_set_max_width(pci, pci->num_lanes); dw_pcie_link_set_max_link_width(pci, pci->num_lanes); }
Add dw_pcie_link_set_max_cap_width() to set PCI_EXP_LNKCAP_MLW. In accordance with the DW PCIe RC/EP HW manuals [1,2,3,...] aside with the PORT_LINK_CTRL_OFF.LINK_CAPABLE and GEN2_CTRL_OFF.NUM_OF_LANES[8:0] field there is another one which needs to be update. It's LINK_CAPABILITIES_REG.PCIE_CAP_MAX_LINK_WIDTH. If it isn't done at the very least the maximum link-width capability CSR won't expose the actual maximum capability. [1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.60a, March 2015, p.1032 [2] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.70a, March 2016, p.1065 [3] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.90a, March 2016, p.1057 ... [X] DesignWare Cores PCI Express Controller Databook - DWC PCIe Endpoint, Version 5.40a, March 2019, p.1396 [X+1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 5.40a, March 2019, p.1266 The commit description is suggested by Serge Semin. Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> --- drivers/pci/controller/dwc/pcie-designware.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)