1 /* $NetBSD: fdt_reset.c,v 1.2 2018/06/30 20:34:43 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: fdt_reset.c,v 1.2 2018/06/30 20:34:43 jmcneill Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/kmem.h> 35 #include <sys/queue.h> 36 37 #include <libfdt.h> 38 #include <dev/fdt/fdtvar.h> 39 40 struct fdtbus_reset_controller { 41 device_t rc_dev; 42 int rc_phandle; 43 const struct fdtbus_reset_controller_func *rc_funcs; 44 45 LIST_ENTRY(fdtbus_reset_controller) rc_next; 46 }; 47 48 static LIST_HEAD(, fdtbus_reset_controller) fdtbus_reset_controllers = 49 LIST_HEAD_INITIALIZER(fdtbus_reset_controllers); 50 51 int 52 fdtbus_register_reset_controller(device_t dev, int phandle, 53 const struct fdtbus_reset_controller_func *funcs) 54 { 55 struct fdtbus_reset_controller *rc; 56 57 rc = kmem_alloc(sizeof(*rc), KM_SLEEP); 58 rc->rc_dev = dev; 59 rc->rc_phandle = phandle; 60 rc->rc_funcs = funcs; 61 62 LIST_INSERT_HEAD(&fdtbus_reset_controllers, rc, rc_next); 63 64 return 0; 65 } 66 67 static struct fdtbus_reset_controller * 68 fdtbus_get_reset_controller(int phandle) 69 { 70 struct fdtbus_reset_controller *rc; 71 72 LIST_FOREACH(rc, &fdtbus_reset_controllers, rc_next) { 73 if (rc->rc_phandle == phandle) 74 return rc; 75 } 76 77 return NULL; 78 } 79 80 struct fdtbus_reset * 81 fdtbus_reset_get_index(int phandle, u_int index) 82 { 83 struct fdtbus_reset_controller *rc; 84 struct fdtbus_reset *rst = NULL; 85 void *rst_priv = NULL; 86 uint32_t *resets = NULL; 87 uint32_t *p; 88 u_int n, reset_cells; 89 int len, resid; 90 91 len = OF_getproplen(phandle, "resets"); 92 if (len <= 0) 93 return NULL; 94 95 resets = kmem_alloc(len, KM_SLEEP); 96 if (OF_getprop(phandle, "resets", resets, len) != len) { 97 kmem_free(resets, len); 98 return NULL; 99 } 100 101 p = resets; 102 for (n = 0, resid = len; resid > 0; n++) { 103 const int rc_phandle = 104 fdtbus_get_phandle_from_native(be32toh(p[0])); 105 if (of_getprop_uint32(rc_phandle, "#reset-cells", &reset_cells)) 106 break; 107 if (n == index) { 108 rc = fdtbus_get_reset_controller(rc_phandle); 109 if (rc == NULL) 110 goto done; 111 rst_priv = rc->rc_funcs->acquire(rc->rc_dev, 112 reset_cells > 0 ? &p[1] : NULL, reset_cells * 4); 113 if (rst_priv) { 114 rst = kmem_alloc(sizeof(*rst), KM_SLEEP); 115 rst->rst_rc = rc; 116 rst->rst_priv = rst_priv; 117 } 118 break; 119 } 120 resid -= (reset_cells + 1) * 4; 121 p += reset_cells + 1; 122 } 123 124 done: 125 if (resets) 126 kmem_free(resets, len); 127 128 return rst; 129 } 130 131 struct fdtbus_reset * 132 fdtbus_reset_get(int phandle, const char *rstname) 133 { 134 struct fdtbus_reset *rst = NULL; 135 char *reset_names = NULL; 136 const char *p; 137 u_int index; 138 int len, resid; 139 140 len = OF_getproplen(phandle, "reset-names"); 141 if (len <= 0) 142 return NULL; 143 144 reset_names = kmem_alloc(len, KM_SLEEP); 145 if (OF_getprop(phandle, "reset-names", reset_names, len) != len) { 146 kmem_free(reset_names, len); 147 return NULL; 148 } 149 150 p = reset_names; 151 for (index = 0, resid = len; resid > 0; index++) { 152 if (strcmp(p, rstname) == 0) { 153 rst = fdtbus_reset_get_index(phandle, index); 154 break; 155 } 156 resid -= strlen(p); 157 p += strlen(p) + 1; 158 } 159 160 if (reset_names) 161 kmem_free(reset_names, len); 162 163 return rst; 164 } 165 166 void 167 fdtbus_reset_put(struct fdtbus_reset *rst) 168 { 169 struct fdtbus_reset_controller *rc = rst->rst_rc; 170 171 rc->rc_funcs->release(rc->rc_dev, rst->rst_priv); 172 kmem_free(rst, sizeof(*rst)); 173 } 174 175 int 176 fdtbus_reset_assert(struct fdtbus_reset *rst) 177 { 178 struct fdtbus_reset_controller *rc = rst->rst_rc; 179 180 return rc->rc_funcs->reset_assert(rc->rc_dev, rst->rst_priv); 181 } 182 183 int 184 fdtbus_reset_deassert(struct fdtbus_reset *rst) 185 { 186 struct fdtbus_reset_controller *rc = rst->rst_rc; 187 188 return rc->rc_funcs->reset_deassert(rc->rc_dev, rst->rst_priv); 189 } 190