This patch fixes an ugly behavior of the IL712 magnetic coupler as used on VOM405. These parts will remember their last state over a power cycle which might cause unwanted behavior.
Signed-off-by: Matthias Fuchs matthias.fuchs@esd.eu --- board/esd/vom405/vom405.c | 35 +++++++++++++++++++++++++++++++++++ 1 files changed, 35 insertions(+), 0 deletions(-)
diff --git a/board/esd/vom405/vom405.c b/board/esd/vom405/vom405.c index fb48022..de35036 100644 --- a/board/esd/vom405/vom405.c +++ b/board/esd/vom405/vom405.c @@ -26,11 +26,40 @@ #include <asm/io.h> #include <command.h> #include <malloc.h> +#include <sja1000.h>
DECLARE_GLOBAL_DATA_PTR;
extern void lxt971_no_sleep(void);
+/* + * 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); +} + int board_early_init_f (void) { /* @@ -77,6 +106,12 @@ int misc_init_r (void) gd->bd->bi_flashstart = 0 - gd->bd->bi_flashsize; gd->bd->bi_flashoffset = 0;
+ /* + * Init magnetic coupler + */ + if (!getenv("noinitcoupler")) + init_coupler(CAN_BA); + return (0); }