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      1 /* $NetBSD: fdt_powerdomain.c,v 1.2 2024/06/12 06:39:28 rin Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2022 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Nick Hudson
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: fdt_powerdomain.c,v 1.2 2024/06/12 06:39:28 rin Exp $");
     34 
     35 #include <sys/param.h>
     36 
     37 #include <sys/bus.h>
     38 #include <sys/kmem.h>
     39 #include <sys/queue.h>
     40 
     41 #include <libfdt.h>
     42 #include <dev/fdt/fdtvar.h>
     43 
     44 
     45 struct fdtbus_powerdomain_controller {
     46 	device_t pdc_dev;
     47 	int pdc_phandle;
     48 
     49 	void *pdc_cookie;
     50 
     51 	int pdc_cells;
     52 
     53 	const struct fdtbus_powerdomain_controller_func *pdc_funcs;
     54 
     55 	LIST_ENTRY(fdtbus_powerdomain_controller) pdc_next;
     56 };
     57 
     58 static LIST_HEAD(, fdtbus_powerdomain_controller) fdtbus_powerdomain_controllers =
     59     LIST_HEAD_INITIALIZER(fdtbus_powerdomain_controllers);
     60 
     61 int
     62 fdtbus_register_powerdomain_controller(device_t dev, int phandle,
     63     const struct fdtbus_powerdomain_controller_func *funcs)
     64 {
     65 	struct fdtbus_powerdomain_controller *pdc;
     66 
     67 	uint32_t cells;
     68 	if (of_getprop_uint32(phandle, "#power-domain-cells", &cells) != 0) {
     69 		aprint_debug_dev(dev, "missing #power-domain-cells");
     70 		return EINVAL;
     71 	}
     72 
     73 	pdc = kmem_alloc(sizeof(*pdc), KM_SLEEP);
     74 	pdc->pdc_dev = dev;
     75 	pdc->pdc_phandle = phandle;
     76 	pdc->pdc_funcs = funcs;
     77 	pdc->pdc_cells = cells;
     78 
     79 	LIST_INSERT_HEAD(&fdtbus_powerdomain_controllers, pdc, pdc_next);
     80 
     81 	return 0;
     82 }
     83 
     84 static struct fdtbus_powerdomain_controller *
     85 fdtbus_powerdomain_lookup(int phandle)
     86 {
     87 	struct fdtbus_powerdomain_controller *pdc;
     88 
     89 	LIST_FOREACH(pdc, &fdtbus_powerdomain_controllers, pdc_next) {
     90 		if (pdc->pdc_phandle == phandle)
     91 			return pdc;
     92 	}
     93 
     94 	return NULL;
     95 }
     96 
     97 static int
     98 fdtbus_powerdomain_enable_internal(int phandle, int index, bool enable)
     99 {
    100 	int len;
    101 	const uint32_t *pds = fdtbus_get_prop(phandle, "power-domains", &len);
    102 
    103 	if (pds == NULL)
    104 		return EINVAL;
    105 
    106 	for (const uint32_t *pd = pds; pd < pds + len / sizeof(*pd); index--) {
    107 		uint32_t pd_node =
    108 		   fdtbus_get_phandle_from_native(be32toh(pd[0]));
    109 		struct fdtbus_powerdomain_controller *pdc =
    110 		    fdtbus_powerdomain_lookup(pd_node);
    111 
    112 		if (pdc == NULL)
    113 			return ENXIO;
    114 
    115 		if (index < 0 || index == 0)
    116 			pdc->pdc_funcs->pdc_enable(pdc->pdc_dev, pd, enable);
    117 		if (index == 0)
    118 			break;
    119 
    120 		pd += pdc->pdc_cells + 1;
    121 	}
    122 
    123 	return 0;
    124 }
    125 
    126 int
    127 fdtbus_powerdomain_enable_index(int phandle, int index)
    128 {
    129 	return fdtbus_powerdomain_enable_internal(phandle, index, true);
    130 }
    131 
    132 int
    133 fdtbus_powerdomain_disable_index(int phandle, int index)
    134 {
    135 	return fdtbus_powerdomain_enable_internal(phandle, index, false);
    136 }
    137 
    138 int
    139 fdtbus_powerdomain_enable(int node)
    140 {
    141 	return fdtbus_powerdomain_enable_index(node, -1);
    142 }
    143 
    144 int
    145 fdtbus_powerdomain_disable(int node)
    146 {
    147 	return fdtbus_powerdomain_disable_index(node, -1);
    148 }
    149