1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2011 Justin Hibbits
5 * Copyright (c) 2009 Nathan Whitehorn
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/bus.h>
33#include <sys/cpu.h>
34#include <sys/kernel.h>
35#include <sys/limits.h>
36#include <sys/module.h>
37
38#include <dev/ofw/ofw_bus.h>
39#include <dev/ofw/openfirm.h>
40
41#include "cpufreq_if.h"
42#include "powerpc/powermac/pmuvar.h"
43
44struct pmufreq_softc {
45	device_t dev;
46	uint32_t minfreq;
47	uint32_t maxfreq;
48	uint32_t curfreq;
49};
50
51static void	pmufreq_identify(driver_t *driver, device_t parent);
52static int	pmufreq_probe(device_t dev);
53static int	pmufreq_attach(device_t dev);
54static int	pmufreq_settings(device_t dev, struct cf_setting *sets, int *count);
55static int	pmufreq_set(device_t dev, const struct cf_setting *set);
56static int	pmufreq_get(device_t dev, struct cf_setting *set);
57static int	pmufreq_type(device_t dev, int *type);
58
59static device_method_t pmufreq_methods[] = {
60	/* Device interface */
61	DEVMETHOD(device_identify,	pmufreq_identify),
62	DEVMETHOD(device_probe,		pmufreq_probe),
63	DEVMETHOD(device_attach,	pmufreq_attach),
64
65	/* cpufreq interface */
66	DEVMETHOD(cpufreq_drv_set,	pmufreq_set),
67	DEVMETHOD(cpufreq_drv_get,	pmufreq_get),
68	DEVMETHOD(cpufreq_drv_type,	pmufreq_type),
69	DEVMETHOD(cpufreq_drv_settings,	pmufreq_settings),
70	{0, 0}
71};
72
73static driver_t pmufreq_driver = {
74	"pmufreq",
75	pmufreq_methods,
76	sizeof(struct pmufreq_softc)
77};
78
79DRIVER_MODULE(pmufreq, cpu, pmufreq_driver, 0, 0);
80
81static void
82pmufreq_identify(driver_t *driver, device_t parent)
83{
84	phandle_t node;
85	uint32_t min_freq;
86
87	node = ofw_bus_get_node(parent);
88	if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
89		return;
90
91	/* Make sure we're not being doubly invoked. */
92	if (device_find_child(parent, "pmufreq", -1) != NULL)
93		return;
94
95	/*
96	 * We attach a child for every CPU since settings need to
97	 * be performed on every CPU in the SMP case.
98	 */
99	if (BUS_ADD_CHILD(parent, 10, "pmufreq", -1) == NULL)
100		device_printf(parent, "add pmufreq child failed\n");
101}
102
103static int
104pmufreq_probe(device_t dev)
105{
106	phandle_t node;
107	uint32_t min_freq;
108
109	if (resource_disabled("pmufreq", 0))
110		return (ENXIO);
111
112	node = ofw_bus_get_node(device_get_parent(dev));
113	/*
114	 * A scalable MPC7455 has min-clock-frequency/max-clock-frequency as OFW
115	 * properties of the 'cpu' node.
116	 */
117	if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
118		return (ENXIO);
119	device_set_desc(dev, "PMU-based frequency scaling");
120	return (0);
121}
122
123static int
124pmufreq_attach(device_t dev)
125{
126	struct pmufreq_softc *sc;
127	phandle_t node;
128
129	sc = device_get_softc(dev);
130	sc->dev = dev;
131
132	node = ofw_bus_get_node(device_get_parent(dev));
133	OF_getprop(node, "min-clock-frequency", &sc->minfreq, sizeof(sc->minfreq));
134	OF_getprop(node, "max-clock-frequency", &sc->maxfreq, sizeof(sc->maxfreq));
135	OF_getprop(node, "rounded-clock-frequency", &sc->curfreq, sizeof(sc->curfreq));
136	sc->minfreq /= 1000000;
137	sc->maxfreq /= 1000000;
138	sc->curfreq /= 1000000;
139
140	cpufreq_register(dev);
141	return (0);
142}
143
144static int
145pmufreq_settings(device_t dev, struct cf_setting *sets, int *count)
146{
147	struct pmufreq_softc *sc;
148
149	sc = device_get_softc(dev);
150	if (sets == NULL || count == NULL)
151		return (EINVAL);
152	if (*count < 2)
153		return (E2BIG);
154
155	/* Return a list of valid settings for this driver. */
156	memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * 2);
157
158	sets[0].freq = sc->maxfreq; sets[0].dev = dev;
159	sets[1].freq = sc->minfreq; sets[1].dev = dev;
160	/* Set high latency for CPU frequency changes, it's a tedious process. */
161	sets[0].lat = INT_MAX;
162	sets[1].lat = INT_MAX;
163	*count = 2;
164
165	return (0);
166}
167
168static int
169pmufreq_set(device_t dev, const struct cf_setting *set)
170{
171	struct pmufreq_softc *sc;
172	int error, speed_sel;
173
174	if (set == NULL)
175		return (EINVAL);
176
177	sc = device_get_softc(dev);
178
179	if (set->freq == sc->maxfreq)
180		speed_sel = 0;
181	else
182		speed_sel = 1;
183
184	error = pmu_set_speed(speed_sel);
185	if (error == 0)
186		sc->curfreq = set->freq;
187
188	return (error);
189}
190
191static int
192pmufreq_get(device_t dev, struct cf_setting *set)
193{
194	struct pmufreq_softc *sc;
195
196	if (set == NULL)
197		return (EINVAL);
198	sc = device_get_softc(dev);
199
200	set->freq = sc->curfreq;
201	set->dev = dev;
202
203	return (0);
204}
205
206static int
207pmufreq_type(device_t dev, int *type)
208{
209
210	if (type == NULL)
211		return (EINVAL);
212
213	*type = CPUFREQ_TYPE_ABSOLUTE;
214	return (0);
215}
216