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tegra_fuse.c revision 1.2 
      1 /* $NetBSD: tegra_fuse.c,v 1.2 2015/11/21 22:52:31 jmcneill Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2015 Jared D. McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include "locators.h"
     30 
     31 #include <sys/cdefs.h>
     32 __KERNEL_RCSID(0, "$NetBSD: tegra_fuse.c,v 1.2 2015/11/21 22:52:31 jmcneill Exp $");
     33 
     34 #include <sys/param.h>
     35 #include <sys/bus.h>
     36 #include <sys/device.h>
     37 #include <sys/intr.h>
     38 #include <sys/systm.h>
     39 #include <sys/kernel.h>
     40 
     41 #include <arm/nvidia/tegra_reg.h>
     42 #include <arm/nvidia/tegra_var.h>
     43 
     44 static int	tegra_fuse_match(device_t, cfdata_t, void *);
     45 static void	tegra_fuse_attach(device_t, device_t, void *);
     46 
     47 struct tegra_fuse_softc {
     48 	device_t		sc_dev;
     49 	bus_space_tag_t		sc_bst;
     50 	bus_space_handle_t	sc_bsh;
     51 };
     52 
     53 static struct tegra_fuse_softc *fuse_softc = NULL;
     54 
     55 CFATTACH_DECL_NEW(tegra_fuse, sizeof(struct tegra_fuse_softc),
     56 	tegra_fuse_match, tegra_fuse_attach, NULL, NULL);
     57 
     58 static int
     59 tegra_fuse_match(device_t parent, cfdata_t cf, void *aux)
     60 {
     61 	return 1;
     62 }
     63 
     64 static void
     65 tegra_fuse_attach(device_t parent, device_t self, void *aux)
     66 {
     67 	struct tegra_fuse_softc * const sc = device_private(self);
     68 	struct tegraio_attach_args * const tio = aux;
     69 	const struct tegra_locators * const loc = &tio->tio_loc;
     70 
     71 	sc->sc_dev = self;
     72 	sc->sc_bst = tio->tio_bst;
     73 	bus_space_subregion(tio->tio_bst, tio->tio_bsh,
     74 	    loc->loc_offset, loc->loc_size, &sc->sc_bsh);
     75 
     76 	KASSERT(fuse_softc == NULL);
     77 	fuse_softc = sc;
     78 
     79 	aprint_naive("\n");
     80 	aprint_normal(": FUSE\n");
     81 }
     82 
     83 uint32_t
     84 tegra_fuse_read(u_int offset)
     85 {
     86 	bus_space_tag_t bst;
     87 	bus_space_handle_t bsh;
     88 
     89 	if (fuse_softc) {
     90 		bst = fuse_softc->sc_bst;
     91 		bsh = fuse_softc->sc_bsh;
     92 	} else {
     93 		bst = &armv7_generic_bs_tag;
     94 		bus_space_subregion(bst, tegra_apb_bsh,
     95 		    TEGRA_FUSE_OFFSET, TEGRA_FUSE_SIZE, &bsh);
     96 	}
     97 
     98 	tegra_car_fuse_enable();
     99 	const uint32_t v = bus_space_read_4(bst, bsh, 0x100 + offset);
    100 	tegra_car_fuse_disable();
    101 
    102 	return v;
    103 }
    104