can: flexcan: add documentation about mailbox organization

This patch adds a short documentation snippet about the mailbox organization as
it's regularly not correct in freescale's datasheets.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 0f5965cc3fbc..eb3ebfb47442 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -230,6 +230,16 @@ struct flexcan_regs {
         u32 rxfir;              /* 0x4c */
         u32 _reserved3[12];     /* 0x50 */
         struct flexcan_mb cantxfg[64];  /* 0x80 */
+        /* FIFO-mode:
+         *                      MB
+         * 0x080...0x08f        0       RX message buffer
+         * 0x090...0x0df        1-5     reserverd
+         * 0x0e0...0x0ff        6-7     8 entry ID table
+         *                              (mx25, mx28, mx35, mx53)
+         * 0x0e0...0x2df        6-7..37 8..128 entry ID table
+         *                              size conf'ed via ctrl2::RFFN
+         *                              (mx6, vf610)
+         */
         u32 _reserved4[408];
         u32 mecr;               /* 0xae0 */
         u32 erriar;             /* 0xae4 */