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tegra_fuse.c revision 1.4.2.2 
      1 /* $NetBSD: tegra_fuse.c,v 1.4.2.2 2015/12/27 12:09:31 skrll 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 <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: tegra_fuse.c,v 1.4.2.2 2015/12/27 12:09:31 skrll Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 #include <sys/device.h>
     35 #include <sys/intr.h>
     36 #include <sys/systm.h>
     37 #include <sys/kernel.h>
     38 
     39 #include <arm/nvidia/tegra_reg.h>
     40 #include <arm/nvidia/tegra_var.h>
     41 
     42 #include <dev/fdt/fdtvar.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 	struct clk		*sc_clk;
     53 	struct fdtbus_reset	*sc_rst;
     54 };
     55 
     56 static struct tegra_fuse_softc *fuse_softc = NULL;
     57 
     58 CFATTACH_DECL_NEW(tegra_fuse, sizeof(struct tegra_fuse_softc),
     59 	tegra_fuse_match, tegra_fuse_attach, NULL, NULL);
     60 
     61 static int
     62 tegra_fuse_match(device_t parent, cfdata_t cf, void *aux)
     63 {
     64 	const char * const compatible[] = { "nvidia,tegra124-efuse", NULL };
     65 	struct fdt_attach_args * const faa = aux;
     66 
     67 	return of_match_compatible(faa->faa_phandle, compatible);
     68 }
     69 
     70 static void
     71 tegra_fuse_attach(device_t parent, device_t self, void *aux)
     72 {
     73 	struct tegra_fuse_softc * const sc = device_private(self);
     74 	struct fdt_attach_args * const faa = aux;
     75 	bus_addr_t addr;
     76 	bus_size_t size;
     77 	int error;
     78 
     79 	if (fdtbus_get_reg(faa->faa_phandle, 0, &addr, &size) != 0) {
     80 		aprint_error(": couldn't get registers\n");
     81 		return;
     82 	}
     83 	sc->sc_clk = fdtbus_clock_get(faa->faa_phandle, "fuse");
     84 	if (sc->sc_clk == NULL) {
     85 		aprint_error(": couldn't get clock fuse\n");
     86 		return;
     87 	}
     88 	sc->sc_rst = fdtbus_reset_get(faa->faa_phandle, "fuse");
     89 	if (sc->sc_rst == NULL) {
     90 		aprint_error(": couldn't get reset fuse\n");
     91 		return;
     92 	}
     93 
     94 	sc->sc_dev = self;
     95 	sc->sc_bst = faa->faa_bst;
     96 	error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
     97 	if (error) {
     98 		aprint_error(": couldn't map %#llx: %d", (uint64_t)addr, error);
     99 		return;
    100 	}
    101 
    102 	KASSERT(fuse_softc == NULL);
    103 	fuse_softc = sc;
    104 
    105 	aprint_naive("\n");
    106 	aprint_normal(": FUSE\n");
    107 }
    108 
    109 uint32_t
    110 tegra_fuse_read(u_int offset)
    111 {
    112 	bus_space_tag_t bst;
    113 	bus_space_handle_t bsh;
    114 
    115 	KASSERT(fuse_softc != NULL);
    116 
    117 	bst = fuse_softc->sc_bst;
    118 	bsh = fuse_softc->sc_bsh;
    119 
    120 	clk_enable(fuse_softc->sc_clk);
    121 	const uint32_t v = bus_space_read_4(bst, bsh, 0x100 + offset);
    122 	clk_disable(fuse_softc->sc_clk);
    123 
    124 	return v;
    125 }
    126