1 /* $NetBSD: meson_resets.c,v 1.2 2019/02/25 19:30:17 jmcneill Exp $ */ 2 3 /*- 4 * Copyright (c) 2017-2019 Jared 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: meson_resets.c,v 1.2 2019/02/25 19:30:17 jmcneill Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/cpu.h> 35 #include <sys/device.h> 36 37 #include <dev/fdt/fdtvar.h> 38 39 #include <dev/clk/clk_backend.h> 40 41 #define RESET_REG(index) (((index) / 32) * 4) 42 #define RESET_MASK(index) __BIT((index) % 32) 43 44 #define LEVEL_OFFSET 0x7c 45 46 static const char * compatible[] = { 47 "amlogic,meson8b-reset", 48 "amlogic,meson-gxbb-reset", 49 NULL 50 }; 51 52 struct meson_resets_softc { 53 device_t sc_dev; 54 bus_space_tag_t sc_bst; 55 bus_space_handle_t sc_bsh; 56 }; 57 58 #define RESET_READ(sc, reg) \ 59 bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg)) 60 #define RESET_WRITE(sc, reg, val) \ 61 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val)) 62 63 static void * 64 meson_resets_acquire(device_t dev, const void *data, size_t len) 65 { 66 if (len != 4) 67 return NULL; 68 69 /* Specifier is an index. Just return it. */ 70 return (void *)(uintptr_t)be32dec(data); 71 } 72 73 static void 74 meson_resets_release(device_t dev, void *priv) 75 { 76 } 77 78 static int 79 meson_resets_assert(device_t dev, void *priv) 80 { 81 struct meson_resets_softc * const sc = device_private(dev); 82 const uintptr_t index = (uintptr_t)priv; 83 84 const bus_size_t reset_reg = RESET_REG(index) + LEVEL_OFFSET; 85 const uint32_t reset_mask = RESET_MASK(index); 86 87 const uint32_t val = RESET_READ(sc, reset_reg); 88 RESET_WRITE(sc, reset_reg, val & ~reset_mask); 89 90 return 0; 91 } 92 93 static int 94 meson_resets_deassert(device_t dev, void *priv) 95 { 96 struct meson_resets_softc * const sc = device_private(dev); 97 const uintptr_t index = (uintptr_t)priv; 98 99 const bus_size_t reset_reg = RESET_REG(index) + LEVEL_OFFSET; 100 const uint32_t reset_mask = RESET_MASK(index); 101 102 const uint32_t val = RESET_READ(sc, reset_reg); 103 RESET_WRITE(sc, reset_reg, val | reset_mask); 104 105 return 0; 106 } 107 108 static const struct fdtbus_reset_controller_func meson_fdtreset_funcs = { 109 .acquire = meson_resets_acquire, 110 .release = meson_resets_release, 111 .reset_assert = meson_resets_assert, 112 .reset_deassert = meson_resets_deassert, 113 }; 114 115 static int 116 meson_resets_match(device_t parent, cfdata_t cf, void *aux) 117 { 118 struct fdt_attach_args * const faa = aux; 119 120 return of_match_compatible(faa->faa_phandle, compatible); 121 } 122 123 static void 124 meson_resets_attach(device_t parent, device_t self, void *aux) 125 { 126 struct meson_resets_softc * const sc = device_private(self); 127 struct fdt_attach_args * const faa = aux; 128 const int phandle = faa->faa_phandle; 129 bus_addr_t addr; 130 bus_size_t size; 131 132 if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) { 133 aprint_error(": couldn't get registers\n"); 134 return; 135 } 136 137 sc->sc_dev = self; 138 sc->sc_bst = faa->faa_bst; 139 if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh) != 0) { 140 aprint_error(": couldn't map registers\n"); 141 return; 142 } 143 144 aprint_naive("\n"); 145 aprint_normal("\n"); 146 147 fdtbus_register_reset_controller(sc->sc_dev, phandle, 148 &meson_fdtreset_funcs); 149 } 150 151 CFATTACH_DECL_NEW(meson_resets, sizeof(struct meson_resets_softc), 152 meson_resets_match, meson_resets_attach, NULL, NULL); 153