1/*-
2 * Copyright (c) 2011 Justin Hibbits
3 * Copyright (c) 2009 Nathan Whitehorn
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
20 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
22 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD$");
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/bus.h>
34#include <sys/cpu.h>
35#include <sys/kernel.h>
36#include <sys/limits.h>
37#include <sys/module.h>
38
39#include <dev/ofw/ofw_bus.h>
40#include <dev/ofw/openfirm.h>
41
42#include "cpufreq_if.h"
43#include "powerpc/powermac/pmuvar.h"
44
45struct pmufreq_softc {
46	device_t dev;
47	uint32_t minfreq;
48	uint32_t maxfreq;
49	uint32_t curfreq;
50};
51
52static void	pmufreq_identify(driver_t *driver, device_t parent);
53static int	pmufreq_probe(device_t dev);
54static int	pmufreq_attach(device_t dev);
55static int	pmufreq_settings(device_t dev, struct cf_setting *sets, int *count);
56static int	pmufreq_set(device_t dev, const struct cf_setting *set);
57static int	pmufreq_get(device_t dev, struct cf_setting *set);
58static int	pmufreq_type(device_t dev, int *type);
59
60static device_method_t pmufreq_methods[] = {
61	/* Device interface */
62	DEVMETHOD(device_identify,	pmufreq_identify),
63	DEVMETHOD(device_probe,		pmufreq_probe),
64	DEVMETHOD(device_attach,	pmufreq_attach),
65
66	/* cpufreq interface */
67	DEVMETHOD(cpufreq_drv_set,	pmufreq_set),
68	DEVMETHOD(cpufreq_drv_get,	pmufreq_get),
69	DEVMETHOD(cpufreq_drv_type,	pmufreq_type),
70	DEVMETHOD(cpufreq_drv_settings,	pmufreq_settings),
71
72	{0, 0}
73};
74
75static driver_t pmufreq_driver = {
76	"pmufreq",
77	pmufreq_methods,
78	sizeof(struct pmufreq_softc)
79};
80
81static devclass_t pmufreq_devclass;
82DRIVER_MODULE(pmufreq, cpu, pmufreq_driver, pmufreq_devclass, 0, 0);
83
84static void
85pmufreq_identify(driver_t *driver, device_t parent)
86{
87	phandle_t node;
88	uint32_t min_freq;
89
90	node = ofw_bus_get_node(parent);
91	if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
92		return;
93
94	/* Make sure we're not being doubly invoked. */
95	if (device_find_child(parent, "pmufreq", -1) != NULL)
96		return;
97
98	/*
99	 * We attach a child for every CPU since settings need to
100	 * be performed on every CPU in the SMP case.
101	 */
102	if (BUS_ADD_CHILD(parent, 10, "pmufreq", -1) == NULL)
103		device_printf(parent, "add pmufreq child failed\n");
104}
105
106static int
107pmufreq_probe(device_t dev)
108{
109	struct pmufreq_softc *sc;
110	phandle_t node;
111	uint32_t min_freq;
112
113	if (resource_disabled("pmufreq", 0))
114		return (ENXIO);
115
116	sc = device_get_softc(dev);
117	node = ofw_bus_get_node(device_get_parent(dev));
118	/*
119	 * A scalable MPC7455 has min-clock-frequency/max-clock-frequency as OFW
120	 * properties of the 'cpu' node.
121	 */
122	if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
123		return (ENXIO);
124	device_set_desc(dev, "PMU-based frequency scaling");
125	return (0);
126}
127
128static int
129pmufreq_attach(device_t dev)
130{
131	struct pmufreq_softc *sc;
132	phandle_t node;
133
134	sc = device_get_softc(dev);
135	sc->dev = dev;
136
137	node = ofw_bus_get_node(device_get_parent(dev));
138	OF_getprop(node, "min-clock-frequency", &sc->minfreq, sizeof(sc->minfreq));
139	OF_getprop(node, "max-clock-frequency", &sc->maxfreq, sizeof(sc->maxfreq));
140	OF_getprop(node, "rounded-clock-frequency", &sc->curfreq, sizeof(sc->curfreq));
141	sc->minfreq /= 1000000;
142	sc->maxfreq /= 1000000;
143	sc->curfreq /= 1000000;
144
145	cpufreq_register(dev);
146	return (0);
147}
148
149static int
150pmufreq_settings(device_t dev, struct cf_setting *sets, int *count)
151{
152	struct pmufreq_softc *sc;
153
154	sc = device_get_softc(dev);
155	if (sets == NULL || count == NULL)
156		return (EINVAL);
157	if (*count < 2)
158		return (E2BIG);
159
160	/* Return a list of valid settings for this driver. */
161	memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * 2);
162
163	sets[0].freq = sc->maxfreq; sets[0].dev = dev;
164	sets[1].freq = sc->minfreq; sets[1].dev = dev;
165	/* Set high latency for CPU frequency changes, it's a tedious process. */
166	sets[0].lat = INT_MAX;
167	sets[1].lat = INT_MAX;
168	*count = 2;
169
170	return (0);
171}
172
173static int
174pmufreq_set(device_t dev, const struct cf_setting *set)
175{
176	struct pmufreq_softc *sc;
177	int error, speed_sel;
178
179	if (set == NULL)
180		return (EINVAL);
181
182	sc = device_get_softc(dev);
183
184	if (set->freq == sc->maxfreq)
185		speed_sel = 0;
186	else
187		speed_sel = 1;
188
189	error = pmu_set_speed(speed_sel);
190	if (error == 0)
191		sc->curfreq = set->freq;
192
193	return (error);
194}
195
196static int
197pmufreq_get(device_t dev, struct cf_setting *set)
198{
199	struct pmufreq_softc *sc;
200
201	if (set == NULL)
202		return (EINVAL);
203	sc = device_get_softc(dev);
204
205	set->freq = sc->curfreq;
206	set->dev = dev;
207
208	return (0);
209}
210
211static int
212pmufreq_type(device_t dev, int *type)
213{
214
215	if (type == NULL)
216		return (EINVAL);
217
218	*type = CPUFREQ_TYPE_ABSOLUTE;
219	return (0);
220}
221
222