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@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