powerpc/fsl_lbc: Add workaround for ELBC-A001 erratum

Simultaneous FCM and GPCM or UPM operation may erroneously trigger
bus monitor timeout.

Set the local bus monitor timeout value to the maximum by setting
LBCR[BMT] = 0 and LBCR[BMTPS] = 0xF.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

2 files changed, 9 insertions, 2 deletions

diff --git a/arch/powerpc/include/asm/fsl_lbc.h b/arch/powerpc/include/asm/fsl_lbc.h
index 5c1bf3466749..8a0b5ece8f76 100644
--- a/arch/powerpc/include/asm/fsl_lbc.h
+++ b/arch/powerpc/include/asm/fsl_lbc.h
@@ -157,6 +157,8 @@ struct fsl_lbc_regs {
 #define LBCR_EPAR_SHIFT    16
 #define LBCR_BMT   0x0000FF00
 #define LBCR_BMT_SHIFT      8
+#define LBCR_BMTPS 0x0000000F
+#define LBCR_BMTPS_SHIFT    0
 #define LBCR_INIT  0x00040000
         __be32 lcrr;            /**< Clock Ratio Register */
 #define LCRR_DBYP    0x80000000
diff --git a/arch/powerpc/sysdev/fsl_lbc.c b/arch/powerpc/sysdev/fsl_lbc.c
index 4fcb5a4e60dd..0608b1657da4 100644
--- a/arch/powerpc/sysdev/fsl_lbc.c
+++ b/arch/powerpc/sysdev/fsl_lbc.c
@@ -184,7 +184,8 @@ int fsl_upm_run_pattern(struct fsl_upm *upm, void __iomem *io_base, u32 mar)
 }
 EXPORT_SYMBOL(fsl_upm_run_pattern);
 
-static int __devinit fsl_lbc_ctrl_init(struct fsl_lbc_ctrl *ctrl)
+static int __devinit fsl_lbc_ctrl_init(struct fsl_lbc_ctrl *ctrl,
+                                       struct device_node *node)
 {
         struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
 
@@ -198,6 +199,10 @@ static int __devinit fsl_lbc_ctrl_init(struct fsl_lbc_ctrl *ctrl)
         /* Enable interrupts for any detected events */
         out_be32(&lbc->lteir, LTEIR_ENABLE);
 
+        /* Set the monitor timeout value to the maximum for erratum A001 */
+        if (of_device_is_compatible(node, "fsl,elbc"))
+                clrsetbits_be32(&lbc->lbcr, LBCR_BMT, LBCR_BMTPS);
+
         return 0;
 }
 
@@ -304,7 +309,7 @@ static int __devinit fsl_lbc_ctrl_probe(struct platform_device *dev)
 
         fsl_lbc_ctrl_dev->dev = &dev->dev;
 
-        ret = fsl_lbc_ctrl_init(fsl_lbc_ctrl_dev);
+        ret = fsl_lbc_ctrl_init(fsl_lbc_ctrl_dev, dev->dev.of_node);
         if (ret < 0)
                 goto err;