1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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/cdefs.h>
31__FBSDID("$FreeBSD$");
32
33#include <sys/param.h>
34#include <sys/systm.h>
35#include <sys/bus.h>
36#include <sys/cpu.h>
37#include <sys/kernel.h>
38#include <sys/limits.h>
39#include <sys/module.h>
40
41#include <dev/ofw/ofw_bus.h>
42#include <dev/ofw/openfirm.h>
43
44#include "cpufreq_if.h"
45#include "powerpc/powermac/pmuvar.h"
46
47struct pmufreq_softc {
48	device_t dev;
49	uint32_t minfreq;
50	uint32_t maxfreq;
51	uint32_t curfreq;
52};
53
54static void	pmufreq_identify(driver_t *driver, device_t parent);
55static int	pmufreq_probe(device_t dev);
56static int	pmufreq_attach(device_t dev);
57static int	pmufreq_settings(device_t dev, struct cf_setting *sets, int *count);
58static int	pmufreq_set(device_t dev, const struct cf_setting *set);
59static int	pmufreq_get(device_t dev, struct cf_setting *set);
60static int	pmufreq_type(device_t dev, int *type);
61
62static device_method_t pmufreq_methods[] = {
63	/* Device interface */
64	DEVMETHOD(device_identify,	pmufreq_identify),
65	DEVMETHOD(device_probe,		pmufreq_probe),
66	DEVMETHOD(device_attach,	pmufreq_attach),
67
68	/* cpufreq interface */
69	DEVMETHOD(cpufreq_drv_set,	pmufreq_set),
70	DEVMETHOD(cpufreq_drv_get,	pmufreq_get),
71	DEVMETHOD(cpufreq_drv_type,	pmufreq_type),
72	DEVMETHOD(cpufreq_drv_settings,	pmufreq_settings),
73	{0, 0}
74};
75
76static driver_t pmufreq_driver = {
77	"pmufreq",
78	pmufreq_methods,
79	sizeof(struct pmufreq_softc)
80};
81
82static devclass_t pmufreq_devclass;
83DRIVER_MODULE(pmufreq, cpu, pmufreq_driver, pmufreq_devclass, 0, 0);
84
85static void
86pmufreq_identify(driver_t *driver, device_t parent)
87{
88	phandle_t node;
89	uint32_t min_freq;
90
91	node = ofw_bus_get_node(parent);
92	if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
93		return;
94
95	/* Make sure we're not being doubly invoked. */
96	if (device_find_child(parent, "pmufreq", -1) != NULL)
97		return;
98
99	/*
100	 * We attach a child for every CPU since settings need to
101	 * be performed on every CPU in the SMP case.
102	 */
103	if (BUS_ADD_CHILD(parent, 10, "pmufreq", -1) == NULL)
104		device_printf(parent, "add pmufreq child failed\n");
105}
106
107static int
108pmufreq_probe(device_t dev)
109{
110	struct pmufreq_softc *sc;
111	phandle_t node;
112	uint32_t min_freq;
113
114	if (resource_disabled("pmufreq", 0))
115		return (ENXIO);
116
117	sc = device_get_softc(dev);
118	node = ofw_bus_get_node(device_get_parent(dev));
119	/*
120	 * A scalable MPC7455 has min-clock-frequency/max-clock-frequency as OFW
121	 * properties of the 'cpu' node.
122	 */
123	if (OF_getprop(node, "min-clock-frequency", &min_freq, sizeof(min_freq)) == -1)
124		return (ENXIO);
125	device_set_desc(dev, "PMU-based frequency scaling");
126	return (0);
127}
128
129static int
130pmufreq_attach(device_t dev)
131{
132	struct pmufreq_softc *sc;
133	phandle_t node;
134
135	sc = device_get_softc(dev);
136	sc->dev = dev;
137
138	node = ofw_bus_get_node(device_get_parent(dev));
139	OF_getprop(node, "min-clock-frequency", &sc->minfreq, sizeof(sc->minfreq));
140	OF_getprop(node, "max-clock-frequency", &sc->maxfreq, sizeof(sc->maxfreq));
141	OF_getprop(node, "rounded-clock-frequency", &sc->curfreq, sizeof(sc->curfreq));
142	sc->minfreq /= 1000000;
143	sc->maxfreq /= 1000000;
144	sc->curfreq /= 1000000;
145
146	cpufreq_register(dev);
147	return (0);
148}
149
150static int
151pmufreq_settings(device_t dev, struct cf_setting *sets, int *count)
152{
153	struct pmufreq_softc *sc;
154
155	sc = device_get_softc(dev);
156	if (sets == NULL || count == NULL)
157		return (EINVAL);
158	if (*count < 2)
159		return (E2BIG);
160
161	/* Return a list of valid settings for this driver. */
162	memset(sets, CPUFREQ_VAL_UNKNOWN, sizeof(*sets) * 2);
163
164	sets[0].freq = sc->maxfreq; sets[0].dev = dev;
165	sets[1].freq = sc->minfreq; sets[1].dev = dev;
166	/* Set high latency for CPU frequency changes, it's a tedious process. */
167	sets[0].lat = INT_MAX;
168	sets[1].lat = INT_MAX;
169	*count = 2;
170
171	return (0);
172}
173
174static int
175pmufreq_set(device_t dev, const struct cf_setting *set)
176{
177	struct pmufreq_softc *sc;
178	int error, speed_sel;
179
180	if (set == NULL)
181		return (EINVAL);
182
183	sc = device_get_softc(dev);
184
185	if (set->freq == sc->maxfreq)
186		speed_sel = 0;
187	else
188		speed_sel = 1;
189
190	error = pmu_set_speed(speed_sel);
191	if (error == 0)
192		sc->curfreq = set->freq;
193
194	return (error);
195}
196
197static int
198pmufreq_get(device_t dev, struct cf_setting *set)
199{
200	struct pmufreq_softc *sc;
201
202	if (set == NULL)
203		return (EINVAL);
204	sc = device_get_softc(dev);
205
206	set->freq = sc->curfreq;
207	set->dev = dev;
208
209	return (0);
210}
211
212static int
213pmufreq_type(device_t dev, int *type)
214{
215
216	if (type == NULL)
217		return (EINVAL);
218
219	*type = CPUFREQ_TYPE_ABSOLUTE;
220	return (0);
221}
222