[src/bouyer-socketcan]: src/sys/arch/arm/allwinner can4linux code, and experi...

[bouyer <bouyer%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/cae28eb45f23
branches:  bouyer-socketcan
changeset: 820899:cae28eb45f23
user:      bouyer <bouyer%NetBSD.org@localhost>
date:      Fri Apr 21 13:08:55 2017 +0000

description:
can4linux code, and experiments, shows that the CAN clock frequency is
AWIN_REF_FREQ, not AWIN_REF_FREQ / 2 as the A20 doc suggests.
Always set the mbuf len to CAN_MTU, this is what linux does.
Set accept filters and clear errors counters on ifconfig up.

We can now send and receive CAN frames.

diffstat:

 sys/arch/arm/allwinner/awin_can.c |  19 ++++++++++++-------
 1 files changed, 12 insertions(+), 7 deletions(-)

diffs (65 lines):

diff -r 7358ac37cf4c -r cae28eb45f23 sys/arch/arm/allwinner/awin_can.c
--- a/sys/arch/arm/allwinner/awin_can.c Fri Apr 21 13:05:15 2017 +0000
+++ b/sys/arch/arm/allwinner/awin_can.c Fri Apr 21 13:08:55 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: awin_can.c,v 1.1.2.4 2017/04/20 17:30:52 bouyer Exp $  */
+/*     $NetBSD: awin_can.c,v 1.1.2.5 2017/04/21 13:08:55 bouyer Exp $  */
 
 /*-
  * Copyright (c) 2017 The NetBSD Foundation, Inc.
@@ -36,7 +36,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(1, "$NetBSD: awin_can.c,v 1.1.2.4 2017/04/20 17:30:52 bouyer Exp $");
+__KERNEL_RCSID(1, "$NetBSD: awin_can.c,v 1.1.2.5 2017/04/21 13:08:55 bouyer Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -168,7 +168,7 @@
        sc->sc_timecaps.cltc_brp_min = 1;
        sc->sc_timecaps.cltc_brp_max = 64;
        sc->sc_timecaps.cltc_brp_inc = 1;
-       sc->sc_timecaps.cltc_clock_freq = AWIN_REF_FREQ / 2;
+       sc->sc_timecaps.cltc_clock_freq = AWIN_REF_FREQ;
        sc->sc_timecaps.cltc_linkmode_caps =
            CAN_LINKMODE_3SAMPLES | CAN_LINKMODE_LISTENONLY |
            CAN_LINKMODE_LOOPBACK;
@@ -274,13 +274,11 @@
                }
        }
        awin_can_write(sc, AWIN_CAN_CMD_REG, AWIN_CAN_CMD_REL_RX_BUF);
-       m->m_len = m->m_pkthdr.len =
-           offsetof(struct can_frame, data[0]) + cf->can_dlc;
+       m->m_len = m->m_pkthdr.len = CAN_MTU;
        ifp->if_ipackets++;
        ifp->if_ibytes += m->m_len;
        m_set_rcvif(m, ifp);
        bpf_mtap(ifp, m);
-       printf("can_input1\n");
        can_input(ifp, m);
 }
 
@@ -300,7 +298,6 @@
                ifp->if_opackets++;
                can_mbuf_tag_clean(m);
                m_set_rcvif(m, ifp);
-               printf("can_input2\n");
                can_input(ifp, m); /* loopback */
                sc->sc_m_transmit = NULL;
                ifp->if_timer = 0;
@@ -503,6 +500,14 @@
 
        awin_can_write(sc, AWIN_CAN_BUS_TIME_REG, reg);
 
+       /* set filters to accept all frames */
+       awin_can_write(sc, AWIN_CAN_ACPC, 0x00000000);
+       awin_can_write(sc, AWIN_CAN_ACPM, 0xffffffff);
+
+       /* clear errors counter */
+       awin_can_write(sc, AWIN_CAN_REC_REG, 0);
+
+       /* leave reset mode and enable interrupts */
        awin_can_exit_reset(sc);
        awin_can_write(sc, AWIN_CAN_INTE_REG,
            AWIN_CAN_INT_TX_FLAG | AWIN_CAN_INT_RX_FLAG | AWIN_CAN_INT_ALLERRS);