ppc4xx: Initialize magnetic couplers in PLU405

[karo-tx-uboot.git] / board / esd / plu405 / plu405.c

diff --git a/board/esd/plu405/plu405.c b/board/esd/plu405/plu405.c
index f14ef7a20f843a88ff0f48e34ae22f2b11301a0e..c733587b2a8557016b69ff8e46d32d026140ff6c 100644 (file)
--- a/board/esd/plu405/plu405.c
+++ b/board/esd/plu405/plu405.c
@@ -26,6 +26,7 @@
 #include <asm/io.h>
 #include <command.h>
 #include <malloc.h>
+#include <sja1000.h>
 
 #undef FPGA_DEBUG
 
@@ -61,6 +62,34 @@ au_image_t au_image[] = {
 
 int N_AU_IMAGES = (sizeof(au_image) / sizeof(au_image[0]));
 
+/*
+ * generate a short spike on the CAN tx line
+ * to bring the couplers in sync
+ */
+void init_coupler(u32 addr)
+{
+       struct sja1000_basic_s *ctrl = (struct sja1000_basic_s *)addr;
+
+       /* reset */
+       out_8(&ctrl->cr, CR_RR);
+
+       /* dominant */
+       out_8(&ctrl->btr0, 0x00); /* btr setup is required */
+       out_8(&ctrl->btr1, 0x14); /* we use 1Mbit/s */
+       out_8(&ctrl->oc, OC_TP1 | OC_TN1 | OC_POL1 |
+             OC_TP0 | OC_TN0 | OC_POL0 | OC_MODE1);
+       out_8(&ctrl->cr, 0x00);
+
+       /* delay */
+       in_8(&ctrl->cr);
+       in_8(&ctrl->cr);
+       in_8(&ctrl->cr);
+       in_8(&ctrl->cr);
+
+       /* reset */
+       out_8(&ctrl->cr, CR_RR);
+}
+
 /* Prototypes */
 int gunzip(void *, int, unsigned char *, unsigned long *);
 
@@ -214,6 +243,13 @@ int misc_init_r(void)
        out_8((void *)DUART1_BA + 1, fctr); /* write FCTR */
        out_8((void *)DUART1_BA + 3, 0);    /* write LCR */
 
+       /*
+        * Init magnetic couplers
+        */
+       if (!getenv("noinitcoupler")) {
+               init_coupler(CAN0_BA);
+               init_coupler(CAN1_BA);
+       }
        return 0;
 }