This patch fixes an ugly behavior of the IL712 magnetic couplers as used on PLU405. 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 --- V2 changes: - use C struct to access CAN controller registes
board/esd/plu405/plu405.c | 56 +++++++++++++++++++++++++++++++++++++++++++++ include/configs/PLU405.h | 3 +- 2 files changed, 58 insertions(+), 1 deletions(-)
diff --git a/board/esd/plu405/plu405.c b/board/esd/plu405/plu405.c index 1841cda..7fd24c1 100644 --- a/board/esd/plu405/plu405.c +++ b/board/esd/plu405/plu405.c @@ -45,6 +45,55 @@ const unsigned char fpgadata[] = */ #include "../common/fpga.c"
+/* + * SJA1000 register layout in basic can mode + */ +struct sja1000_basic_s { + u8 cr; + u8 cmr; + u8 sr; + u8 ir; + u8 ac; + u8 am; + u8 btr0; + u8 btr1; + u8 oc; + u8 txb[10]; + u8 rxb[10]; + u8 unused; + u8 cdr; +}; + +#define SJA1000_CR_RR 0x01 +#define SJA1000_OC_MODE0 0x01 + +/* + * 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, 0x20 | SJA1000_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, ~SJA1000_OC_MODE0); + out_8(&ctrl->cr, 0x20); + + /* delay */ + in_8(&ctrl->cr); + in_8(&ctrl->cr); + in_8(&ctrl->cr); + in_8(&ctrl->cr); + + /* reset */ + out_8(&ctrl->cr, 0x20 | SJA1000_CR_RR); +} + /* Prototypes */ int gunzip(void *, int, unsigned char *, unsigned long *);
@@ -198,6 +247,13 @@ 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; }
diff --git a/include/configs/PLU405.h b/include/configs/PLU405.h index 07fc715..b6740de 100644 --- a/include/configs/PLU405.h +++ b/include/configs/PLU405.h @@ -298,7 +298,8 @@ /* * External Bus Controller (EBC) Setup */ -#define CAN_BA 0xF0000000 /* CAN Base Address */ +#define CAN0_BA 0xF0000000 /* CAN0 Base Address */ +#define CAN1_BA 0xF0000100 /* CAN1 Base Address */ #define DUART0_BA 0xF0000400 /* DUART Base Address */ #define DUART1_BA 0xF0000408 /* DUART Base Address */ #define RTC_BA 0xF0000500 /* RTC Base Address */