fsl/fman: Workaround for Errata A-007273

Errata A-007273 (For FMan V3 devices only):
FMan soft reset is not finished properly if one
of the Ethernet MAC clocks is disabled

Workaround:
Re-enable all disabled MAC clocks through the DCFG_CCSR_DEVDISR2
register prior to issuing an FMAN soft reset.
Re-disable the MAC clocks after the FMAN soft reset is done.

Signed-off-by: Igal Liberman <igal.liberman@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 88 insertions, 16 deletions

diff --git a/drivers/net/ethernet/freescale/fman/fman.c b/drivers/net/ethernet/freescale/fman/fman.c
index 79a210aaf0bb..ea83712a6d62 100644
--- a/drivers/net/ethernet/freescale/fman/fman.c
+++ b/drivers/net/ethernet/freescale/fman/fman.c
@@ -35,6 +35,7 @@
 #include "fman.h"
 #include "fman_muram.h"
 
+#include <linux/fsl/guts.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/module.h>
@@ -1871,6 +1872,90 @@ err_fm_state:
         return -EINVAL;
 }
 
+static int fman_reset(struct fman *fman)
+{
+        u32 count;
+        int err = 0;
+
+        if (fman->state->rev_info.major < 6) {
+                iowrite32be(FPM_RSTC_FM_RESET, &fman->fpm_regs->fm_rstc);
+                /* Wait for reset completion */
+                count = 100;
+                do {
+                        udelay(1);
+                } while (((ioread32be(&fman->fpm_regs->fm_rstc)) &
+                         FPM_RSTC_FM_RESET) && --count);
+                if (count == 0)
+                        err = -EBUSY;
+
+                goto _return;
+        } else {
+                struct device_node *guts_node;
+                struct ccsr_guts __iomem *guts_regs;
+                u32 devdisr2, reg;
+
+                /* Errata A007273 */
+                guts_node =
+                        of_find_compatible_node(NULL, NULL,
+                                                "fsl,qoriq-device-config-2.0");
+                if (!guts_node) {
+                        dev_err(fman->dev, "%s: Couldn't find guts node\n",
+                                __func__);
+                        goto guts_node;
+                }
+
+                guts_regs = of_iomap(guts_node, 0);
+                if (!guts_regs) {
+                        dev_err(fman->dev, "%s: Couldn't map %s regs\n",
+                                __func__, guts_node->full_name);
+                        goto guts_regs;
+                }
+#define FMAN1_ALL_MACS_MASK     0xFCC00000
+#define FMAN2_ALL_MACS_MASK     0x000FCC00
+                /* Read current state */
+                devdisr2 = ioread32be(&guts_regs->devdisr2);
+                if (fman->dts_params.id == 0)
+                        reg = devdisr2 & ~FMAN1_ALL_MACS_MASK;
+                else
+                        reg = devdisr2 & ~FMAN2_ALL_MACS_MASK;
+
+                /* Enable all MACs */
+                iowrite32be(reg, &guts_regs->devdisr2);
+
+                /* Perform FMan reset */
+                iowrite32be(FPM_RSTC_FM_RESET, &fman->fpm_regs->fm_rstc);
+
+                /* Wait for reset completion */
+                count = 100;
+                do {
+                        udelay(1);
+                } while (((ioread32be(&fman->fpm_regs->fm_rstc)) &
+                         FPM_RSTC_FM_RESET) && --count);
+                if (count == 0) {
+                        iounmap(guts_regs);
+                        of_node_put(guts_node);
+                        err = -EBUSY;
+                        goto _return;
+                }
+
+                /* Restore devdisr2 value */
+                iowrite32be(devdisr2, &guts_regs->devdisr2);
+
+                iounmap(guts_regs);
+                of_node_put(guts_node);
+
+                goto _return;
+
+guts_regs:
+                of_node_put(guts_node);
+guts_node:
+                dev_dbg(fman->dev, "%s: Didn't perform FManV3 reset due to Errata A007273!\n",
+                        __func__);
+        }
+_return:
+        return err;
+}
+
 static int fman_init(struct fman *fman)
 {
         struct fman_cfg *cfg = NULL;
@@ -1914,22 +1999,9 @@ static int fman_init(struct fman *fman)
                 fman->liodn_base[i] = liodn_base;
         }
 
-        /* FMan Reset (supported only for FMan V2) */
-        if (fman->state->rev_info.major >= 6) {
-                /* Errata A007273 */
-                dev_dbg(fman->dev, "%s: FManV3 reset is not supported!\n",
-                        __func__);
-        } else {
-                iowrite32be(FPM_RSTC_FM_RESET, &fman->fpm_regs->fm_rstc);
-                /* Wait for reset completion */
-                count = 100;
-                do {
-                        udelay(1);
-                } while (((ioread32be(&fman->fpm_regs->fm_rstc)) &
-                         FPM_RSTC_FM_RESET) && --count);
-                if (count == 0)
-                        return -EBUSY;
-        }
+        err = fman_reset(fman);
+        if (err)
+                return err;
 
         if (ioread32be(&fman->qmi_regs->fmqm_gs) & QMI_GS_HALT_NOT_BUSY) {
                 resume(fman->fpm_regs);