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      1 /* $NetBSD: fdt_platform.c,v 1.3 2025/09/08 23:38:18 rin Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2017 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: fdt_platform.c,v 1.3 2025/09/08 23:38:18 rin Exp $");
     31 
     32 #include <sys/param.h>
     33 
     34 #include <dev/ofw/openfirm.h>
     35 
     36 #include <dev/fdt/fdtvar.h>
     37 #include <dev/fdt/fdt_platform.h>
     38 
     39 const struct fdt_platform *
     40 fdt_platform_find(void)
     41 {
     42 	static const struct fdt_platform_info *booted_platform = NULL;
     43 	__link_set_decl(fdt_platforms, struct fdt_platform_info);
     44 	struct fdt_platform_info * const *info;
     45 
     46 	if (booted_platform == NULL) {
     47 		const struct fdt_platform_info *best_info = NULL;
     48 		const int phandle = OF_peer(0);
     49 		int match, best_match = 0;
     50 
     51 		__link_set_foreach(info, fdt_platforms) {
     52 			const struct device_compatible_entry compat_data[] = {
     53 				{ .compat = (*info)->fpi_compat },
     54 				DEVICE_COMPAT_EOL
     55 			};
     56 
     57 			match = of_compatible_match(phandle, compat_data);
     58 			if (match > best_match) {
     59 				best_match = match;
     60 				best_info = *info;
     61 			}
     62 		}
     63 
     64 		booted_platform = best_info;
     65 	}
     66 
     67 	/*
     68 	 * No SoC specific platform was found. Try to find a generic
     69 	 * platform definition and use that if available.
     70 	 */
     71 	if (booted_platform == NULL) {
     72 		__link_set_foreach(info, fdt_platforms) {
     73 			if (strcmp((*info)->fpi_compat, FDT_PLATFORM_DEFAULT) == 0) {
     74 				booted_platform = *info;
     75 				break;
     76 			}
     77 		}
     78 	}
     79 
     80 	return booted_platform == NULL ? NULL : booted_platform->fpi_ops;
     81 }
     82