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>

diff --git a/drivers/net/ethernet/freescale/fman/fman.c b/drivers/net/ethernet/freescale/fman/fman.c
index 79a210aaf0bbd69d86ce830a45909ae8ede07f83..ea83712a6d62cf89136f19fbe6b0ce1cc18370ab 100644 (file)
--- 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);