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fdt_i2c.c revision 1.2.18.2 
      1 /* $NetBSD: fdt_i2c.c,v 1.2.18.2 2017/12/03 11:37:01 jdolecek Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2015 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_i2c.c,v 1.2.18.2 2017/12/03 11:37:01 jdolecek Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 #include <sys/kmem.h>
     35 
     36 #include <libfdt.h>
     37 #include <dev/fdt/fdtvar.h>
     38 
     39 struct fdtbus_i2c_controller {
     40 	device_t i2c_dev;
     41 	int i2c_phandle;
     42 	const struct fdtbus_i2c_controller_func *i2c_funcs;
     43 
     44 	struct fdtbus_i2c_controller *i2c_next;
     45 };
     46 
     47 static struct fdtbus_i2c_controller *fdtbus_i2c = NULL;
     48 
     49 int
     50 fdtbus_register_i2c_controller(device_t dev, int phandle,
     51     const struct fdtbus_i2c_controller_func *funcs)
     52 {
     53 	struct fdtbus_i2c_controller *i2c;
     54 
     55 	i2c = kmem_alloc(sizeof(*i2c), KM_SLEEP);
     56 	i2c->i2c_dev = dev;
     57 	i2c->i2c_phandle = phandle;
     58 	i2c->i2c_funcs = funcs;
     59 
     60 	i2c->i2c_next = fdtbus_i2c;
     61 	fdtbus_i2c = i2c;
     62 
     63 	return 0;
     64 }
     65 
     66 static struct fdtbus_i2c_controller *
     67 fdtbus_get_i2c_controller(int phandle)
     68 {
     69 	struct fdtbus_i2c_controller *i2c;
     70 
     71 	for (i2c = fdtbus_i2c; i2c; i2c = i2c->i2c_next) {
     72 		if (i2c->i2c_phandle == phandle) {
     73 			return i2c;
     74 		}
     75 	}
     76 
     77 	return NULL;
     78 }
     79 
     80 i2c_tag_t
     81 fdtbus_get_i2c_tag(int phandle)
     82 {
     83 	struct fdtbus_i2c_controller *i2c;
     84 
     85 	i2c = fdtbus_get_i2c_controller(phandle);
     86 	if (i2c == NULL)
     87 		return NULL;
     88 
     89 	return i2c->i2c_funcs->get_tag(i2c->i2c_dev);
     90 }
     91