xref: /netbsd-src/sys/arch/arm/apple/apple_pmgr.c (revision abcecf9b421259c78ab50964b3ca4cf086e54fb2)
1 /* $NetBSD: apple_pmgr.c,v 1.2 2022/05/10 08:10:28 skrll 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: apple_pmgr.c,v 1.2 2022/05/10 08:10:28 skrll 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  * Power manager registers
46  */
47 #define PMGR_PS_TARGET_MASK	__BITS(3, 0)
48 #define PMGR_PS_ACTUAL_MASK	__BITS(7, 4)
49 #define  PMGR_PS_ACTIVE		0xf
50 #define  PMGR_PS_PWRGATE	0x0
51 
52 struct apple_pmgr_softc {
53 	device_t sc_dev;
54 	bus_space_tag_t sc_bst;
55 	bus_space_handle_t sc_bsh;
56 };
57 
58 #define PMGR_READ(sc, reg) \
59 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
60 #define	PMGR_WRITE(sc, reg, val) \
61 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
62 
63 
64 static const struct device_compatible_entry compat_data[] = {
65 	{ .compat = "apple,pmgr" },
66 	DEVICE_COMPAT_EOL
67 };
68 
69 static void
apple_pmgr_enable(device_t dev,const uint32_t * data,bool enable)70 apple_pmgr_enable(device_t dev, const uint32_t *data, bool enable)
71 {
72 	struct apple_pmgr_softc * const sc = device_private(dev);
73 	const uint32_t pstate = enable ? PMGR_PS_ACTIVE : PMGR_PS_PWRGATE;
74 	const int phandle = fdtbus_get_phandle_from_native(be32dec(data));
75 
76 	fdtbus_powerdomain_enable(phandle);
77 
78 	bus_size_t off;
79 	bus_size_t size;
80 	if (fdtbus_get_reg(phandle, 0, &off, &size) != 0 || size != 4) {
81 		aprint_error(": invalid 'reg' property\n");
82 		return;
83 	}
84 
85 	uint32_t val = PMGR_READ(sc, off);
86 
87 	val &= ~PMGR_PS_TARGET_MASK;
88 	val |= __SHIFTIN(pstate, PMGR_PS_TARGET_MASK);
89 	PMGR_WRITE(sc, off, val);
90 
91 	for (int timo = 0; timo < 100; timo++) {
92 		val = PMGR_READ(sc, off);
93 		if (__SHIFTOUT(val, PMGR_PS_ACTUAL_MASK) == pstate)
94 			break;
95 		delay(1);
96 	}
97 }
98 
99 
100 static int
apple_pmgr_match(device_t parent,cfdata_t cf,void * aux)101 apple_pmgr_match(device_t parent, cfdata_t cf, void *aux)
102 {
103 	struct fdt_attach_args * const faa = aux;
104 
105 	return of_compatible_match(faa->faa_phandle, compat_data);
106 }
107 
108 
109 static void
apple_pmgr_attach(device_t parent,device_t self,void * aux)110 apple_pmgr_attach(device_t parent, device_t self, void *aux)
111 {
112 	struct apple_pmgr_softc * const sc = device_private(self);
113 	struct fdt_attach_args * const faa = aux;
114 	const int phandle = faa->faa_phandle;
115 
116 	bus_addr_t pmgr_addr;
117 	bus_size_t pmgr_size;
118 
119 	int error = fdtbus_get_reg(phandle, 0, &pmgr_addr, &pmgr_size);
120 	if (error) {
121 		aprint_error(": couldn't get registers\n");
122 		return;
123 	}
124 
125 	sc->sc_dev = self;
126 	sc->sc_bst = faa->faa_bst;
127 
128 	error = bus_space_map(faa->faa_bst, pmgr_addr, pmgr_size, 0,
129 	    &sc->sc_bsh);
130 	if (error) {
131 		aprint_error(": couldn't map registers: %d\n", error);
132 		return;
133 	}
134 
135 	aprint_naive("\n");
136 	aprint_normal(": Apple PMGR\n");
137 
138 	for (int node = OF_child(phandle); node; node = OF_peer(node)) {
139 		static const struct device_compatible_entry compat_ps[] = {
140 			{ .compat = "apple,pmgr-pwrstate" },
141 			DEVICE_COMPAT_EOL
142 		};
143 
144 		if (!of_compatible_match(node, compat_ps))
145 			continue;
146 
147 		static struct fdtbus_powerdomain_controller_func funcs = {
148 			.pdc_enable = apple_pmgr_enable,
149 		};
150 
151 		fdtbus_register_powerdomain_controller(self, node, &funcs);
152 	}
153 }
154 
155 CFATTACH_DECL_NEW(apple_pmgr, sizeof(struct apple_pmgr_softc),
156     apple_pmgr_match, apple_pmgr_attach, NULL, NULL);
157