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fdt_i2c.c revision 1.8 
      1 /* $NetBSD: fdt_i2c.c,v 1.8 2020/06/12 03:32:30 thorpej 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 1.8 2020/06/12 03:32:30 thorpej 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_i2c_controller {
     41 	device_t i2c_dev;
     42 	int i2c_phandle;
     43 	const struct fdtbus_i2c_controller_func *i2c_funcs;
     44 
     45 	LIST_ENTRY(fdtbus_i2c_controller) i2c_next;
     46 };
     47 
     48 static LIST_HEAD(, fdtbus_i2c_controller) fdtbus_i2c_controllers =
     49     LIST_HEAD_INITIALIZER(fdtbus_i2c_controllers);
     50 
     51 int
     52 fdtbus_register_i2c_controller(device_t dev, int phandle,
     53     const struct fdtbus_i2c_controller_func *funcs)
     54 {
     55 	struct fdtbus_i2c_controller *i2c;
     56 
     57 	i2c = kmem_alloc(sizeof(*i2c), KM_SLEEP);
     58 	i2c->i2c_dev = dev;
     59 	i2c->i2c_phandle = phandle;
     60 	i2c->i2c_funcs = funcs;
     61 
     62 	LIST_INSERT_HEAD(&fdtbus_i2c_controllers, i2c, i2c_next);
     63 
     64 	return 0;
     65 }
     66 
     67 static struct fdtbus_i2c_controller *
     68 fdtbus_get_i2c_controller(int phandle)
     69 {
     70 	struct fdtbus_i2c_controller *i2c;
     71 
     72 	LIST_FOREACH(i2c, &fdtbus_i2c_controllers, i2c_next) {
     73 		if (i2c->i2c_phandle == phandle)
     74 			return i2c;
     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 
     92 i2c_tag_t
     93 fdtbus_i2c_acquire(int phandle, const char *prop)
     94 {
     95 	int i2c_phandle;
     96 
     97 	i2c_phandle = fdtbus_get_phandle(phandle, prop);
     98 	if (i2c_phandle == -1)
     99 		return NULL;
    100 
    101 	return fdtbus_get_i2c_tag(i2c_phandle);
    102 }
    103 
    104 device_t
    105 fdtbus_attach_i2cbus(device_t dev, int phandle, i2c_tag_t tag, cfprint_t print)
    106 {
    107 	struct i2cbus_attach_args iba;
    108 	prop_dictionary_t devs, props;
    109 	device_t ret;
    110 	u_int address_cells;
    111 
    112 	devs = prop_dictionary_create();
    113 	if (of_getprop_uint32(phandle, "#address-cells", &address_cells))
    114 		address_cells = 1;
    115 
    116 	of_enter_i2c_devs(devs, phandle, address_cells * 4, 0);
    117 
    118 	memset(&iba, 0, sizeof(iba));
    119 	iba.iba_tag = tag;
    120 	iba.iba_child_devices = prop_dictionary_get(devs, "i2c-child-devices");
    121 	if (iba.iba_child_devices)
    122 		prop_object_retain(iba.iba_child_devices);
    123 	prop_object_release(devs);
    124 
    125 	props = device_properties(dev);
    126 	prop_dictionary_set_bool(props, "i2c-no-indirect-config", true);
    127 
    128 	ret = config_found_ia(dev, "i2cbus", &iba, print);
    129 	if (iba.iba_child_devices)
    130 		prop_object_release(iba.iba_child_devices);
    131 
    132 	return ret;
    133 }
    134