staging/hfi1: set Gen3 half-swing for integrated devices

[karo-tx-linux.git] / drivers / staging / rdma / hfi1 / pcie.c

diff --git a/drivers/staging/rdma/hfi1/pcie.c b/drivers/staging/rdma/hfi1/pcie.c
index 8317b07d722a5ebcdb9ebe07d60fc437cfc2d690..9917faff823cc812c7ac1ae164717a58a9a4b88d 100644 (file)
--- a/drivers/staging/rdma/hfi1/pcie.c
+++ b/drivers/staging/rdma/hfi1/pcie.c
@@ -866,6 +866,83 @@ static void arm_gasket_logic(struct hfi1_devdata *dd)
        read_csr(dd, ASIC_PCIE_SD_HOST_CMD);
 }
 
+/*
+ * CCE_PCIE_CTRL long name helpers
+ * We redefine these shorter macros to use in the code while leaving
+ * chip_registers.h to be autogenerated from the hardware spec.
+ */
+#define LANE_BUNDLE_MASK              CCE_PCIE_CTRL_PCIE_LANE_BUNDLE_MASK
+#define LANE_BUNDLE_SHIFT             CCE_PCIE_CTRL_PCIE_LANE_BUNDLE_SHIFT
+#define LANE_DELAY_MASK               CCE_PCIE_CTRL_PCIE_LANE_DELAY_MASK
+#define LANE_DELAY_SHIFT              CCE_PCIE_CTRL_PCIE_LANE_DELAY_SHIFT
+#define MARGIN_OVERWRITE_ENABLE_SHIFT CCE_PCIE_CTRL_XMT_MARGIN_OVERWRITE_ENABLE_SHIFT
+#define MARGIN_SHIFT                  CCE_PCIE_CTRL_XMT_MARGIN_SHIFT
+#define MARGIN_G1_G2_OVERWRITE_MASK   CCE_PCIE_CTRL_XMT_MARGIN_GEN1_GEN2_OVERWRITE_ENABLE_MASK
+#define MARGIN_G1_G2_OVERWRITE_SHIFT  CCE_PCIE_CTRL_XMT_MARGIN_GEN1_GEN2_OVERWRITE_ENABLE_SHIFT
+#define MARGIN_GEN1_GEN2_MASK         CCE_PCIE_CTRL_XMT_MARGIN_GEN1_GEN2_MASK
+#define MARGIN_GEN1_GEN2_SHIFT        CCE_PCIE_CTRL_XMT_MARGIN_GEN1_GEN2_SHIFT
+
+ /*
+  * Write xmt_margin for full-swing (WFR-B) or half-swing (WFR-C).
+  */
+static void write_xmt_margin(struct hfi1_devdata *dd, const char *fname)
+{
+       u64 pcie_ctrl;
+       u64 xmt_margin;
+       u64 xmt_margin_oe;
+       u64 lane_delay;
+       u64 lane_bundle;
+
+       pcie_ctrl = read_csr(dd, CCE_PCIE_CTRL);
+
+       /*
+        * For Discrete, use full-swing.
+        *  - PCIe TX defaults to full-swing.
+        *    Leave this register as default.
+        * For Integrated, use half-swing
+        *  - Copy xmt_margin and xmt_margin_oe
+        *    from Gen1/Gen2 to Gen3.
+        */
+       if (dd->pcidev->device == PCI_DEVICE_ID_INTEL1) { /* integrated */
+               /* extract initial fields */
+               xmt_margin = (pcie_ctrl >> MARGIN_GEN1_GEN2_SHIFT)
+                             & MARGIN_GEN1_GEN2_MASK;
+               xmt_margin_oe = (pcie_ctrl >> MARGIN_G1_G2_OVERWRITE_SHIFT)
+                                & MARGIN_G1_G2_OVERWRITE_MASK;
+               lane_delay = (pcie_ctrl >> LANE_DELAY_SHIFT) & LANE_DELAY_MASK;
+               lane_bundle = (pcie_ctrl >> LANE_BUNDLE_SHIFT)
+                              & LANE_BUNDLE_MASK;
+
+               /*
+                * For A0, EFUSE values are not set.  Override with the
+                * correct values.
+                */
+               if (is_ax(dd)) {
+                       /*
+                        * xmt_margin and OverwiteEnabel should be the
+                        * same for Gen1/Gen2 and Gen3
+                        */
+                       xmt_margin = 0x5;
+                       xmt_margin_oe = 0x1;
+                       lane_delay = 0xF; /* Delay 240ns. */
+                       lane_bundle = 0x0; /* Set to 1 lane. */
+               }
+
+               /* overwrite existing values */
+               pcie_ctrl = (xmt_margin << MARGIN_GEN1_GEN2_SHIFT)
+                       | (xmt_margin_oe << MARGIN_G1_G2_OVERWRITE_SHIFT)
+                       | (xmt_margin << MARGIN_SHIFT)
+                       | (xmt_margin_oe << MARGIN_OVERWRITE_ENABLE_SHIFT)
+                       | (lane_delay << LANE_DELAY_SHIFT)
+                       | (lane_bundle << LANE_BUNDLE_SHIFT);
+
+               write_csr(dd, CCE_PCIE_CTRL, pcie_ctrl);
+       }
+
+       dd_dev_dbg(dd, "%s: program XMT margin, CcePcieCtrl 0x%llx\n",
+                  fname, pcie_ctrl);
+}
+
 /*
  * Do all the steps needed to transition the PCIe link to Gen3 speed.
  */
@@ -1064,11 +1141,8 @@ retry:
 
        /*
         * step 5d: program XMT margin
-        * Right now, leave the default alone.  To change, do a
-        * read-modify-write of:
-        *      CcePcieCtrl.XmtMargin
-        *      CcePcieCtrl.XmitMarginOverwriteEnable
         */
+       write_xmt_margin(dd, __func__);
 
        /* step 5e: disable active state power management (ASPM) */
        dd_dev_info(dd, "%s: clearing ASPM\n", __func__);