PCI: dwc: Read DWC IP core version from register

Since DWC PCIe v4.70a, the controller version and version type can be read
from the PORT_LOGIC.PCIE_VERSION_OFF and PORT_LOGIC.PCIE_VERSION_TYPE_OFF
registers respectively.

Read the version from those registers and warn if if's different from the
version we got from the device tree.

We can only read the version after platform-specific drivers have done any
DBI-related initialization, such as reference clock activation.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20220624143947.8991-5-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 1e35542..ffbd3af 100644 (file)
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -711,6 +711,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
        ep->phys_base = res->start;
        ep->addr_size = resource_size(res);
 
+       dw_pcie_version_detect(pci);
+
        dw_pcie_iatu_detect(pci);
 
        ep->ib_window_map = devm_kcalloc(dev,

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 1314bb1..479ab6c 100644 (file)
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -405,6 +405,8 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
                }
        }
 
+       dw_pcie_version_detect(pci);
+
        dw_pcie_iatu_detect(pci);
 
        dw_pcie_setup_rc(pp);

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index f10a7d5..cbb36cc 100644 (file)
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -16,6 +16,30 @@
 #include "../../pci.h"
 #include "pcie-designware.h"
 
+void dw_pcie_version_detect(struct dw_pcie *pci)
+{
+       u32 ver;
+
+       /* The content of the CSR is zero on DWC PCIe older than v4.70a */
+       ver = dw_pcie_readl_dbi(pci, PCIE_VERSION_NUMBER);
+       if (!ver)
+               return;
+
+       if (pci->version && pci->version != ver)
+               dev_warn(pci->dev, "Versions don't match (%08x != %08x)\n",
+                        pci->version, ver);
+       else
+               pci->version = ver;
+
+       ver = dw_pcie_readl_dbi(pci, PCIE_VERSION_TYPE);
+
+       if (pci->type && pci->type != ver)
+               dev_warn(pci->dev, "Types don't match (%08x != %08x)\n",
+                        pci->type, ver);
+       else
+               pci->type = ver;
+}
+
 /*
  * These interfaces resemble the pci_find_*capability() interfaces, but these
  * are for configuring host controllers, which are bridges *to* PCI devices but

diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 6b81530..7899808 100644 (file)
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -85,6 +85,9 @@
 #define PCIE_PORT_MULTI_LANE_CTRL      0x8C0
 #define PORT_MLTI_UPCFG_SUPPORT                BIT(7)
 
+#define PCIE_VERSION_NUMBER            0x8F8
+#define PCIE_VERSION_TYPE              0x8FC
+
 #define PCIE_ATU_VIEWPORT              0x900
 #define PCIE_ATU_REGION_INBOUND                BIT(31)
 #define PCIE_ATU_REGION_OUTBOUND       0
@@ -279,6 +282,7 @@ struct dw_pcie {
        struct dw_pcie_ep       ep;
        const struct dw_pcie_ops *ops;
        u32                     version;
+       u32                     type;
        int                     num_lanes;
        int                     link_gen;
        u8                      n_fts[2];
@@ -290,6 +294,8 @@ struct dw_pcie {
 #define to_dw_pcie_from_ep(endpoint)   \
                container_of((endpoint), struct dw_pcie, ep)
 
+void dw_pcie_version_detect(struct dw_pcie *pci);
+
 u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap);
 u16 dw_pcie_find_ext_capability(struct dw_pcie *pci, u8 cap);