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tsrtc.c revision 1.4 
      1 /*	$NetBSD: tsrtc.c,v 1.4 2008/03/28 19:05:49 tsutsui Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1995, 1996 Carnegie-Mellon University.
      5  * All rights reserved.
      6  *
      7  * Author: Chris G. Demetriou
      8  *
      9  * Permission to use, copy, modify and distribute this software and
     10  * its documentation is hereby granted, provided that both the copyright
     11  * notice and this permission notice appear in all copies of the
     12  * software, derivative works or modified versions, and any portions
     13  * thereof, and that both notices appear in supporting documentation.
     14  *
     15  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     16  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     17  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     18  *
     19  * Carnegie Mellon requests users of this software to return to
     20  *
     21  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     22  *  School of Computer Science
     23  *  Carnegie Mellon University
     24  *  Pittsburgh PA 15213-3890
     25  *
     26  * any improvements or extensions that they make and grant Carnegie the
     27  * rights to redistribute these changes.
     28  */
     29 
     30 #include <sys/cdefs.h>
     31 __KERNEL_RCSID(0, "$NetBSD: tsrtc.c,v 1.4 2008/03/28 19:05:49 tsutsui Exp $");
     32 
     33 #include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
     34 
     35 #include <sys/param.h>
     36 #include <sys/kernel.h>
     37 #include <sys/systm.h>
     38 #include <sys/device.h>
     39 
     40 #include <machine/bus.h>
     41 
     42 #include <dev/clock_subr.h>
     43 #include <dev/ic/mc146818reg.h>
     44 #include <dev/ic/mc146818var.h>
     45 
     46 #include <evbarm/tsarm/tspldvar.h>
     47 #include <evbarm/tsarm/tsarmreg.h>
     48 
     49 int	tsrtc_match(device_t, cfdata_t, void *);
     50 void	tsrtc_attach(device_t, device_t, void *);
     51 
     52 struct tsrtc_softc {
     53 	struct mc146818_softc	sc_mc;
     54 	bus_space_tag_t		sc_iot;
     55 	bus_space_handle_t	sc_dath;
     56 	bus_space_handle_t	sc_idxh;
     57 };
     58 
     59 CFATTACH_DECL_NEW(tsrtc, sizeof (struct tsrtc_softc),
     60     tsrtc_match, tsrtc_attach, NULL, NULL);
     61 
     62 void	tsrtc_write(struct mc146818_softc *, u_int, u_int);
     63 u_int	tsrtc_read(struct mc146818_softc *, u_int);
     64 
     65 
     66 int
     67 tsrtc_match(device_t parent, cfdata_t cf, void *aux)
     68 {
     69 	struct tspld_attach_args *aa = aux;
     70 	struct tsrtc_softc tsrtc, *sc;
     71 	unsigned int t1, t2;
     72 	static int found = -1;
     73 
     74 	if (found != -1)
     75 		return found;
     76 
     77 	sc = &tsrtc;
     78 	sc->sc_iot = aa->ta_iot;
     79 	if (bus_space_map(sc->sc_iot, TS7XXX_IO8_HWBASE + TS7XXX_RTCIDX, 1, 0,
     80 		 &sc->sc_idxh))
     81 		return (0);
     82 	if (bus_space_map(sc->sc_iot, TS7XXX_IO8_HWBASE + TS7XXX_RTCDAT, 1, 0,
     83 		 &sc->sc_dath))
     84 		return (0);
     85 
     86 	/* Read from the seconds counter. */
     87 	t1 = FROMBCD(tsrtc_read((struct mc146818_softc *)sc, MC_SEC));
     88 	if (t1 > 59)
     89 		goto unmap;
     90 
     91 	/* Wait, then look again. */
     92 	DELAY(1100000);
     93 	t2 = FROMBCD(tsrtc_read((struct mc146818_softc *)sc, MC_SEC));
     94 	if (t2 > 59)
     95 		goto unmap;
     96 
     97         /* If [1,2) seconds have passed since, call it a clock. */
     98 	if ((t1 + 1) % 60 == t2 || (t1 + 2) % 60 == t2)
     99 		found = 1;
    100 
    101  unmap:
    102 	bus_space_unmap(sc->sc_iot, sc->sc_idxh, 1);
    103 	bus_space_unmap(sc->sc_iot, sc->sc_dath, 1);
    104 
    105 	return (found);
    106 }
    107 
    108 void
    109 tsrtc_attach(device_t parent, device_t self, void *aux)
    110 {
    111 	struct tsrtc_softc *sc = device_private(self);
    112 	struct tspld_attach_args *aa = aux;
    113 
    114 	sc->sc_iot = aa->ta_iot;
    115 	if (bus_space_map(sc->sc_iot, TS7XXX_IO8_HWBASE + TS7XXX_RTCIDX,
    116 	    1, 0, &sc->sc_idxh))
    117 		panic("tsrtc_attach: couldn't map clock I/O space");
    118 	if (bus_space_map(sc->sc_iot, TS7XXX_IO8_HWBASE + TS7XXX_RTCDAT,
    119 	    1, 0, &sc->sc_dath))
    120 		panic("tsrtc_attach: couldn't map clock I/O space");
    121 
    122 	sc->sc_mc.sc_year0 = 2000;
    123 	sc->sc_mc.sc_mcread = tsrtc_read;
    124 	sc->sc_mc.sc_mcwrite = tsrtc_write;
    125 	sc->sc_mc.sc_flag = MC146818_BCD;
    126 	mc146818_attach(&sc->sc_mc);
    127 
    128 	aprint_error("\n");
    129 
    130 	(*sc->sc_mc.sc_mcwrite)((struct mc146818_softc *)sc, MC_REGB,
    131 		MC_REGB_24HR);
    132 }
    133 
    134 void
    135 tsrtc_write(struct mc146818_softc *mc_sc, u_int reg, u_int datum)
    136 {
    137 	struct tsrtc_softc *sc = (struct tsrtc_softc *)mc_sc;
    138 
    139 	bus_space_write_1(sc->sc_iot, sc->sc_idxh, 0, reg);
    140 	bus_space_write_1(sc->sc_iot, sc->sc_dath, 0, datum);
    141 }
    142 
    143 u_int
    144 tsrtc_read(struct mc146818_softc *mc_sc, u_int reg)
    145 {
    146 	struct tsrtc_softc *sc = (struct tsrtc_softc *)mc_sc;
    147 	u_int datum;
    148 
    149 	bus_space_write_1(sc->sc_iot, sc->sc_idxh, 0, reg);
    150 	datum = bus_space_read_1(sc->sc_iot, sc->sc_dath, 0);
    151 
    152 	return (datum);
    153 }
    154