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ofw_i2c_subr.c revision 1.2 
      1 /*	$NetBSD: ofw_i2c_subr.c,v 1.2 2025/09/16 11:37:17 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright 1998
      5  * Digital Equipment Corporation. All rights reserved.
      6  *
      7  * This software is furnished under license and may be used and
      8  * copied only in accordance with the following terms and conditions.
      9  * Subject to these conditions, you may download, copy, install,
     10  * use, modify and distribute this software in source and/or binary
     11  * form. No title or ownership is transferred hereby.
     12  *
     13  * 1) Any source code used, modified or distributed must reproduce
     14  *    and retain this copyright notice and list of conditions as
     15  *    they appear in the source file.
     16  *
     17  * 2) No right is granted to use any trade name, trademark, or logo of
     18  *    Digital Equipment Corporation. Neither the "Digital Equipment
     19  *    Corporation" name nor any trademark or logo of Digital Equipment
     20  *    Corporation may be used to endorse or promote products derived
     21  *    from this software without the prior written permission of
     22  *    Digital Equipment Corporation.
     23  *
     24  * 3) This software is provided "AS-IS" and any express or implied
     25  *    warranties, including but not limited to, any implied warranties
     26  *    of merchantability, fitness for a particular purpose, or
     27  *    non-infringement are disclaimed. In no event shall DIGITAL be
     28  *    liable for any damages whatsoever, and in particular, DIGITAL
     29  *    shall not be liable for special, indirect, consequential, or
     30  *    incidental damages or damages for lost profits, loss of
     31  *    revenue or loss of use, whether such damages arise in contract,
     32  *    negligence, tort, under statute, in equity, at law or otherwise,
     33  *    even if advised of the possibility of such damage.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 __KERNEL_RCSID(0, "$NetBSD: ofw_i2c_subr.c,v 1.2 2025/09/16 11:37:17 thorpej Exp $");
     38 
     39 #include <sys/param.h>
     40 #include <sys/device.h>
     41 #include <sys/kmem.h>
     42 #include <sys/systm.h>
     43 #include <dev/ofw/openfirm.h>
     44 #include <dev/i2c/i2cvar.h>
     45 
     46 /*
     47  * Iterate over the subtree of a i2c controller node.
     48  * Add all sub-devices into an array as part of the controller's
     49  * device properties.
     50  * This is used by the i2c bus attach code to do direct configuration.
     51  */
     52 prop_array_t
     53 of_copy_i2c_devs(int ofnode, size_t cell_size, int addr_shift)
     54 {
     55 	int node, len;
     56 	char name[32];
     57 	uint64_t reg64;
     58 	uint32_t reg32;
     59 	uint64_t addr;
     60 	prop_array_t array = NULL;
     61 	prop_dictionary_t dev;
     62 
     63 	for (node = OF_child(ofnode); node; node = OF_peer(node)) {
     64 		if (OF_getprop(node, "name", name, sizeof(name)) <= 0)
     65 			continue;
     66 		len = OF_getproplen(node, "reg");
     67 		addr = 0;
     68 		if (cell_size == 8 && len >= sizeof(reg64)) {
     69 			if (OF_getprop(node, "reg", &reg64, sizeof(reg64))
     70 			    < sizeof(reg64))
     71 				continue;
     72 			addr = be64toh(reg64);
     73 			/*
     74 			 * The i2c bus number (0 or 1) is encoded in bit 33
     75 			 * of the register, but we encode it in bit 8 of
     76 			 * i2c_addr_t.
     77 			 */
     78 			if (addr & 0x100000000)
     79 				addr = (addr & 0xff) | 0x100;
     80 		} else if (cell_size == 4 && len >= sizeof(reg32)) {
     81 			if (OF_getprop(node, "reg", &reg32, sizeof(reg32))
     82 			    < sizeof(reg32))
     83 				continue;
     84 			addr = be32toh(reg32);
     85 		} else {
     86 			continue;
     87 		}
     88 		addr >>= addr_shift;
     89 		if (addr == 0) continue;
     90 
     91 		if (array == NULL)
     92 			array = prop_array_create();
     93 
     94 		dev = prop_dictionary_create();
     95 		prop_dictionary_set_string(dev, "name", name);
     96 		prop_dictionary_set_uint32(dev, "addr", addr);
     97 		prop_dictionary_set_uint64(dev, "cookie", node);
     98 		prop_dictionary_set_uint32(dev, "cookietype", I2C_COOKIE_OF);
     99 		of_to_dataprop(dev, node, "compatible", "compatible");
    100 		prop_array_add(array, dev);
    101 		prop_object_release(dev);
    102 	}
    103 
    104 	return array;
    105 }
    106