Home | History | Annotate | Line # | Download | only in nvidia
tegra_fuse.c revision 1.3 
      1 /* $NetBSD: tegra_fuse.c,v 1.3 2015/12/13 17:39:19 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 1.3 2015/12/13 17:39:19 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 #include <dev/fdt/fdtvar.h>
     45 
     46 static int	tegra_fuse_match(device_t, cfdata_t, void *);
     47 static void	tegra_fuse_attach(device_t, device_t, void *);
     48 
     49 struct tegra_fuse_softc {
     50 	device_t		sc_dev;
     51 	bus_space_tag_t		sc_bst;
     52 	bus_space_handle_t	sc_bsh;
     53 };
     54 
     55 static struct tegra_fuse_softc *fuse_softc = NULL;
     56 
     57 CFATTACH_DECL_NEW(tegra_fuse, sizeof(struct tegra_fuse_softc),
     58 	tegra_fuse_match, tegra_fuse_attach, NULL, NULL);
     59 
     60 static int
     61 tegra_fuse_match(device_t parent, cfdata_t cf, void *aux)
     62 {
     63 	const char * const compatible[] = { "nvidia,tegra124-efuse", NULL };
     64 	struct fdt_attach_args * const faa = aux;
     65 
     66 	return of_match_compatible(faa->faa_phandle, compatible);
     67 }
     68 
     69 static void
     70 tegra_fuse_attach(device_t parent, device_t self, void *aux)
     71 {
     72 	struct tegra_fuse_softc * const sc = device_private(self);
     73 	struct fdt_attach_args * const faa = aux;
     74 	bus_addr_t addr;
     75 	bus_size_t size;
     76 	int error;
     77 
     78 	if (fdtbus_get_reg(faa->faa_phandle, 0, &addr, &size) != 0) {
     79 		aprint_error(": couldn't get registers\n");
     80 		return;
     81 	}
     82 
     83 	sc->sc_dev = self;
     84 	sc->sc_bst = faa->faa_bst;
     85 	error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
     86 	if (error) {
     87 		aprint_error(": couldn't map %#llx: %d", (uint64_t)addr, error);
     88 		return;
     89 	}
     90 
     91 	KASSERT(fuse_softc == NULL);
     92 	fuse_softc = sc;
     93 
     94 	aprint_naive("\n");
     95 	aprint_normal(": FUSE\n");
     96 }
     97 
     98 uint32_t
     99 tegra_fuse_read(u_int offset)
    100 {
    101 	bus_space_tag_t bst;
    102 	bus_space_handle_t bsh;
    103 
    104 	if (fuse_softc) {
    105 		bst = fuse_softc->sc_bst;
    106 		bsh = fuse_softc->sc_bsh;
    107 	} else {
    108 		bst = &armv7_generic_bs_tag;
    109 		bus_space_subregion(bst, tegra_apb_bsh,
    110 		    TEGRA_FUSE_OFFSET, TEGRA_FUSE_SIZE, &bsh);
    111 	}
    112 
    113 	tegra_car_fuse_enable();
    114 	const uint32_t v = bus_space_read_4(bst, bsh, 0x100 + offset);
    115 	tegra_car_fuse_disable();
    116 
    117 	return v;
    118 }
    119