1 /* $NetBSD: tegra_fuse.c,v 1.4 2015/12/22 22:10:36 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 <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: tegra_fuse.c,v 1.4 2015/12/22 22:10:36 jmcneill 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